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HUMAN POWERED FLYWHEEL MOTORCONCEPT, DESIGN, DYNAMICS AND APPLICATIONS

by

J. P. MODAK

Emeritus Professor of Mechanical Engineering and Dean (R&D)Priyadarshini College of Engineering,

Near Central Reserve Police Force Campus, Hingna Road, MIDC,NAGPUR 440019 (INDIA)

Keywords : Human Power, Flywheel, Motor, Peddling, Mechanisms,Torsionally Flexible Clutches, Rural Based Applications.

Summary : The author and his associates have developed HumanPowered Process Machines for several rural based production activitiessuch as low level water lifting, bricks making (rectangular as well askeyed cross section) for various combinations of raw materials, alge

formation process, wood turning, winnowing, wood strips cutting, smithshammer (drop forged/ cam type) electricity generation etc.

The evolved machine system comprised of three subsystems namely (1)Energy Unit : Comprising of a suitable peddling mechanism, speed risegear pair and Flywheel conceptualized as Human Powered Flywheel Motor(HPFM) (2) Suitable torsionally flexible clutch and torque amplificationgear pair and (3) a process unit. Though human capacity is 0.1hp

continuous duty, the processes needing power even upto 6.0 hp can beenergised by such a machine concept.

This development is realized over last 3 decades (1979-2006).

After evolving MHADA machine for brick making which was mainly anintution based backed up by general past mechanical design experience.Since, this machine proved to be functionally feasible and economicallyviable though developed mainly based on intution without any designdata, subsequently it was decided to develop its all subsystems such as

(1) peddling mechanisms (2) human powered flywheel motor, (3)torsionally flexible clutches and (4) establishing functional & economicviability of various rural based applications enumerated above.

The basis of this development is generation of design data of thesesubsystems through establishing Generalized Experimental Data BasedModels through executed necessary research projects.

This entire work is published through around 60 publications, guiding (1)four candidates for Masters (by research) degree in Engineering and (2)nearly five candidates for doctoral degree (Ph.D.). Around 4 sponsoredprojects are completed based on this research.

This development has conceived several employment guarantee schemesfor semiskilled /unskilled labour for the population of the 3rdworld.

The complete research is presented through a treatise leading to thedegree of Doctor of Science (D.Sc.) of the author of this lecture.

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1.0 MHADA MACHINE:

1.1. Need for a Human Powered Brick Making MachineMaharashtra Housing and Area Development Authority (MHADA), Mumbai

(India) offered a sponsored project towards evolution of a manufacturingsystem which can work as an employment guarantee scheme for

unskilled/semiskilled unemployed labour available in plenty in India andfor some countries of the 3rdworld. As the project was offered by MHADAobviously the product had to be some building component preferablybricks. Brick composition was proposed to be lime: Flyash; Sand (1/2/4 byweight) in order to solve the problem of flyash utilization of thermalstations.

Bricks with such a composition gain strength simply by weather and /orwater curing so conventional energy sources are conserved which

otherwise could have been used in baking normal earthen bricks.

In view of all above it boiled down to design and fabricate a human

powered brick making machine to manufacture lime-flyash-sand bricksand to design and demonstrate operating production system for themanufacturing of such bricks. This project based on intution was

completed in 1979-82 [1 & 4].

1.2. Basic Concept of the MachineOn an average, the power produced by a man is approximately 75W(0.10hp) [23], if he works continuously. Therefore human power may be

used for a process if the power requirement is maximum of 75W. Ifprocess power requirement is more than 75W and if the process can be ofan intermittent nature without affecting the end product, a machine-

system can be developed that stored the energy. Figure 1.1 describes the

schematic arrangement of the proposed machine.

Essentially, the machine consists of three subsystems : (1) the energyunit, (2) appropriate transmission, and (3) the process unit. The energy

Numbers in the square brackets denote references listed at the end of the lecture.

Figure 1.1 Plan View of the Schematic arrangement of the Machine

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unit consists of a conventional bicycle mechanism, a pair of speed-

increasing gears G having a speed rise ratio G = 3 to 4 and a flywheel.The transmission consists of a single-jaw spiral clutch [24] and thetorque-amplification gear pair G having torque amplification ratio G = 4.For brick manufacturing, a process unit PU consists of an auger, cone and

die, conventionally used for motorised brick-extruders for the manufacture

of clay bricks [51]

The suggested machine system uses human energy achieved by peddlingand stores this energy in a flywheel at an energy-input rate convenient to

the peddler. After storing the maximum possible energy in the flywheel(peddling time could be 1-2 minutes) the same can be made available forthe actuation of any process unit by making available the energy stored inthe flywheel through a suitable clutch and torque-amplification if needed.Thus the flywheel will decelerate depending on the actual resisting torque

offered by the process. It implies that the peddler does not pedal whilethe flywheel is supplying energy to the process-unit.

1.3 Availability of Design Data for the Proposed Machine

The literature search we made did not produce data regarding whatshould be the numerical value of G and the moment of inertia of theflywheel so that this man-machine system could store maximum energy inthe flywheel for the shortest possible peddling time. Obviously we wanted

the most compatible system with the minimum possible internal humanenergy loss. Thus no design data were available for the energy unit. Wecalled this unit a Human-Powered Flywheel Motor [6].

Upon engagement of the clutch there is a rapid transfer of momentumand kinetic energy between the energy unit and the process unit. Theprocess unit input shaft is thus instantaneously accelerated and, after

reaching the maximum speed, is subjected to deceleration. Thisdeceleration is induced by the resistance offered on account of extrusion

of lime-flyash-sand paste contained in the extruder. Thus the process

unit input shaft is in a transient state of motion (rigid-body angularvelocity of the auger is changing). The literature available as far as

design of an extruder is concerned pertains only to the manufacture ofclay bricks using a motorized machine wherein an auger shaft is always ina steady state of motion. The literature search did not provide anyinformation regarding horse-power requirement, optimum auger speed,

details of geometry of blade, cone and die for such an extruder formanufacturing lime-flyash-sand, or only lime-flyash, bricks. Thus no

design-data was available for the process unit nor for a single-jaw spiral

clutch and torque-amplification gears. Here, the emphasis is on severityof initial mechanical shock and its associated severe adverse effects suchas excessive stressing of the system under severe impact, randomvibrations and rapid wear.

In view of the foregoing the main parameters and dimensioning of the

components were decided essentially based on intuition and general pastmechanical design experience. Accordingly the machine is designed and

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is described in Figure 1.2. A photograph of this machine is given in Figure

1.3.

Figure 1.2 : Mechanical Parts of the Machine1) Die 2) Conveyor drum 3) Hopper 4) Wooden mould 5) Mould stand 6) Screw Conveyor

7) Conveyor shaft 8) Bearing 9) Gear I 10) Pinion I shaft 12) Bearing 13) Movable jaw ofclutch 14) Clutch lever 15) Fixed jaw of clutch 16) Flywheel shaft 17) Flywheel 18) Bearing19) Pinion II 20) Gear II 21) Free wheel 22) Intermediate shaft 23) Bearing 24) Chainwheel 25) Roller chain 26) Drivers seat 27) Handle 28) Bracket 29) Frame

1.4 Mechanical Design of the MachineThe machine has a die (1; see Figure 1.2) that is bolted to the conveyor

drum (2). The die has a variable cross-section, convergent near the

conveyor-drum end to compact the material and to prevent rotation in thedie, while a subsequent uniform section gives the desired shape to thecolumn. The material is fed through the hopper (3).

The detachable mould (4), lined from inside by acrylic material tominimize friction, is kept level and in contact with a die on the mould

stand (5). The mould can be lifted or pulled from the stand.

Figure 1.3 Brick Making Machine Energized by HPFM

The screw-conveyor (6) is mounted on a conveyor shaft (7). The shaft issupported by two bearings (8) outside the conveyor drum. Gear I (9) ismounted on the conveyor shaft between two bearings. Pinion-I (10)

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which meshes with gear I is mounted on a pinion shaft (11), between two

bearings (12). The left overhang of the pinion shaft is splined and takesthe movable half of the clutch (13). Axial movement of clutch is possibleusing the lever (14).

The fixed half of the clutch (15) is keyed to the flywheel shaft (16) which

is supported by two bearings (18). The flywheel (17) was readilyavailable in a market of old machine parts. This flywheel is mounted onthe shaft at the extreme left. Gear pair II (19 and 20) is mountedbetween the flywheel shaft and an intermediate shaft on which the rear

sprocket (21) of the bicycle chain drive is mounted. Thus, the totalspeed-rise ratio between the bicycle driving crank and the flywheel is keptat 6.24. Out of this, the chain drive provides a speed-rise ratio of 2.6 andthe remainder is provided by gear pair II (same as G described in Figure1.1). The crank, chain wheel and pedal assembly is identical to the oneused for the bicycle. An existing bicycle frame is used to provide seat and

handle support. Specifications of the major machine parts are describedin table 1.

A spiral jaw clutch is used because it is expected that this type of clutch islikely to consume less energy for its own operation as compared to thefriction clutch [52]. In order to ensure that the energy does not flow fromthe flywheel to the driving pedals after the clutch is engaged, it isnecessary to have a one-way clutch between the driving pedals and theflywheel.

1.5 Manufacturing Process

The complete process of manufacturing bricks has two stages: (1)manufacture of columns of the paste of brick ingredients with water, and(2) conversion of these columns into bricks. The proposed machinemanufactures the columns.

1.5.1 Working of the machine

A properly prepared mixture of dry ingredients with water is pouredthrough hopper (3) into the conveyor drum (2) of the screw conveyor.The water content may be 25-30% by weight of dry mixture.

A person pedals the mechanism for about a minute with the clutch in thedisengaged position. In this duration the flywheel of about 1m diameter

and 0.1m rim width can be accelerated from rest to about 700-800 rpm.

During pedalling he has to overcome only the inertia of the flywheel. Theoperator pedals for about one and a half-hours before wishing to have a

change of activity or some food or drink. (he gets a rest period of 6-10seconds between two consecutive extrusion operations).

After attaining the predecided maximum flywheel speed pedalling is

stopped. The clutch is immediately engaged and the energy stored in theflywheel is made available to the process unit through the clutch (is

immediately engaged and the energy stored in the flywheel is made

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available to the process unit through the clutch) and the torque

amplification gears G. The clay extrusion immediately commences uponthe clutch engagement and it continues for 6-10 seconds, until such timeas the flywheel comes to rest. A clay column about 1.3m long is obtainedat the end of the extrusion. The extrusion time depends on the type ofclay, the flywheel terminal speed, and the size and shape of the cross

sections of the die. The machine has been tried for extrusion of variousclays, various die cross sections and various flywheel terminal speeds atthe end of the pedalling. Table 2 provides information about these trials.

Table 1.1 : Specifications of major machine parts

No. Name of component Major dimensions (mm) Material

1 Intermediate shaft Length = 740, max. diam=52 SAE 1030 mild steel

2 Flywheel shaft Length = 740, max. diam = 72 SAE 1030 mild steel

3 Conveyor shaft Length = 1030, max. diam=68 SAE 1030 mild steel

4 Flywheel Outer diam=1000, rim

Width=1000, no. of arms=6Hub diam=100, wgt=50kg

Cast iron

5 Pinion I PCD=190, face width=50

No. of teeth=24

Cast iron

6 Gear I PCD=455, face width=50

No. of teeth=91

Cast iron

7 Pinion II PCD=130, face width=55

No. of teeth=24

Cast iron

8 Floating gear PCD=533.5, face width=55

No. of teeth =97

Cast iron

9 Clutch Length of one-half = 118

Mean diam = 67

Cast steel

10 Conveyor Screw Outer diam = 180, pitch=160

Helix angle = 23%

Mild Steel

11 Bearings Intermediate shaft

Flywheel shaft

Conveyor shaft

6008

6409

6312

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Table 1.2 : Performance of human-powered brick-making machine

for different mixes and their composition

Sr.No.

Composition byweight

CrossSectionmm xmm

Max.speedofflywhe

el(RPM)

Columnlength(m)

Extrusiontime(sec)

Strengthwithout

bakingkgr/mm2

MN/m2Mpa

HorsePower(hp)

KW

1 River clay

+ sand(1.1)

90 x

90

750 0.70 10 0.27 2.65 1.95 1.45

2 Blackcotton

soil+flyash+sand(1:2:1)

90x 90 750650

550

1.040.72

0.70

57.5

10

0.205 2.01 3.909.95

1.05

2.911.45

0.783

3 Blackcottonsoil+flyash-sand

(1:2:2)

90 x90

750650550

0.530.300.25

101530

0.205 2.01 1.950.980.35

1.450.730.26

4 Lime+flyash+sand(1:1:2)

90 x9090 x90

750450750

0.901.000.75

713

0.700.42

6.94.1

2.790.54

2.080.40

5 Lime+flyash+sand

(1:2:4)

750 0.75 7 - - 2.97 2.08

6 Lime+flyash(1.1)

(1.2)(1.3)

90 x90 450450450

0.900.900.90

151515

0.400.200.15

3.92.01.5

0.470.470.47

0.350.350.35

1.5.2 Conversion of brick column into bricks

Sometimes the extruded column might have a bulge, which must be

removed by pressure from a flat plate before the column is detached fromthe mixture in the die. The mould is then taken manually to a column-

curing platform and demoulded. Immediately after demoulding, a column

is not enough stiff to be cut. After about one hour, however, it becomesstiff enough to be cut into bricks of standard length of 200mm. On an

average in one cycle of operation of the machine (total cycle time beingmaximum 70 seconds), 6-7 bricks are manufactured.

These bricks are cured by sprinkling water on them or by covering them

with a damp cloth for 28 days. During the process of curing a low-temperature cementing reaction undergoes which imparts fairly high

strength and water-absorption resistance to these bricks. Therefore, it is

necessary to provide a storage facility for 30x1500 (=45000) bricksbefore they are fully prepared for sale. Additional land or proper storageracks for vertical storing of these bricks may also be needed. Fiftycolumns can be accommodated on one curing platform 6m long and 1mwide.

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A team of five unskilled workers is required for performing various manual

operations of this kind of brick making. Out of these five, one pedals theflywheel, two remove the bulge from the column, detach the mould, liftthe mould from the stand and carry the mould to the curing platform onwhich moulds are demoulded. The remaining two bring the preparedmixture to the machine hopper.

1.6 Economic Viability

This machine was operated for one month by a team of five workers on an

eight-hours shift. The actual time of machine operation was five and one-half hours a day. The team was required to perform several othersupporting operations such as preparation of the mixture for the next day,curing of bricks manufactured earlier, shifting of one-day-old bricks fromthe curing platform to the storing stack, maintenance of the machine, andmaintenance of the factory (i.e. premises, housing, machine and other

accessories described earlier). These operations needed two and one-halfhours per shift. During the first week of machine operation, the number

of bricks manufactured were 400 per day; this output increased steadilyto 1000 bricks per day in the last week of machine operation. This steadyincrease in production level was on account of proper synchronization ofvarious human activities which a team of five workers is required toperform every day. There was a learning process about themanufacturing activity as the teammates continued to work together onthe process. The production level would increase with experience. The

machine capacity is about 2000 bricks per day, so that a further increasein production level with experience would be expected.

A machine site can therefore be considered to be a small factorycomprising a machine, enough vertical brick storing racks, curingplatforms, enough space for storage of raw material, etc.

The cost of manufacturing of lime flyash sand bricks was calculated for

various locations in Vidarbha (a region in Maharashtra state of India).These locations were comprised of (1) a state industrial developmentcorporation of a very big town like Nagpur, (2) a state industrial

development corporation of district places like Bhandara, and locationsnear raw materials like Rajura (near the lime quarries), Chandrapur (near2200-MW thermal power station producting an abundance of flyash) andon the bed of river Knhan (nearness of sand). A detailed breakdown ofcost is given in table 3, based on a production of 1000 bricks per day.

The current selling price is Rs. 1.15 per brick. This implies that on an

average the monthly earning of the entrepreneur of this small-scalefactory manufacturing lime flyash sand bricks or lime flyash bricks is at

least Rs. 10,000/-month. The average earning of a middle-class person inthe nearby locality is around Rs. 7000 per month. This establishes theeconomic viability of the proposal for human-powered brick manufacture.Further, this also justifies the development of a human-powered process

machine needing a power requirement far in excess of human capacity incontinuous operation in general and of a human-powered brick-making

machine in particular.

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Table 1.3 : Total cost of manufacture of lime-flyash-sand brick

Cost of material per brick (NP)Plantlocation

Lime Flyash Sand Totalmateri

al

Labour

Charges

(NP)

Depreciati

on(NP)

Recovery of

investment

w/interest (NP)

TotalManufa

cturingcost

(NP)

Remarks

NagpurMIDC

34.00 5.00 8.00 47.00 7.00 1.00 5.00 60.00

BhandaraMIDC

35.00 6.00 4.00 45.00 7.00 1.00 4.00 57.00

Chandrap

ur MIDC34.00 18.00

*2.50

4.00 56.00

*40.50

6.00 1.00 4.00 67.00

*50.00

*After

getting flyashlocally

Rajura 30.00 19.00

*5.00

4.00 53.00

*39.00

6.00 1.00 4.00 64.00

*50.00

*After

gettingflyash at

Chandrapur

Koradi 34.00 2.50 4.00 40.50 6.00 1.00 4.50 52.00

Kanhan 35.00 6.00 1.00 42.00 6.00 1.00 6.00 53.00

1.7 Further Development

After developing this first Human Powered Machine (1979-82) for themanufacture of lime fly ash sand bricks, Modak and his associates workedon further development of (1) This concept of the use of human powered

energy source [5-22, 25-32, 34-37, 64-66] and (2) For feeding such a

power to various applications [38-50, 53, 54, 56, 62] needing power far inexcess of human continuous capacity. What follows in the subsequent

sections are the details of this further development. A D.Sc. treatisebased on this complete work is being submitted to Nagpur University(India) in Dec. 2007.

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2.0 IMPROVEMENT OF GENERAL MECHANICAL DESIGN OFTHE MACHINE

2.1 Improvement Based on Performance Feedback.

MHADA machine was operated almost for one month after establishing its

functional viability. During this month 50,000 bricks are produced(assuming 25 working days). We learnt about the various operational and

design draw backs of this machine. In view of these draw backs a newmachine was designed [2 & 3] keeping in view main aspects enlisted asunder.

[1] Optimum average auger speed should be 30 to 40 rpm [51] for

getting maximum extrusion.

[2] Maximum speed rise ratio should be 2.33 x 2.56.0. Out of this 2.33from chain drive and 2.5 [24] from G in view of keeping adverse

dynamic effects lowest possible.

[3] This decides maximum flywheel speed to be 480 rpm. Assuming thatflywheel on-load would be subjected to approximately constant

retardation.

[4] This gives the rim diameter of the flywheel to be 80 cms and 150 kgf

weight at 240 rpm maximum speed.

[5] The spiral jaw clutch to be replaced in future machines by torsionallymore flexible clutches [29]. This is so because spiral jaw clutch canoperate satisfactorily only upto 300 rpm maximum speed [24] in

order to avoid its abrupt tip failure. Ordinary friction clutch cannotbe a substitute as it consumed 30% of the flywheel energy [52]

during initial slippage.

[6] Chain drive to be made inclined at maximum 60oinclination [24] for

making the drive compact with top side in tension.

[7] Concept can be applied to energise machines needing horse powerup to 6 hp as the maximum energy storage can be up to 2700 kgf.min a minutes time with 5 seconds of energy exhaustion time and 15%

frictional losses.

[8] Processes not getting affected by constantly changing input speeds

should only be powered by such an energy source.

2.2 Conceptual Design of a Novel Gearbox [33].

In such a manually energized machine the speed of process unit input

shaft is all the while changing. It is necessary to operate a process unit ata fairly constant speed in order to use the already established design dataof the process unit for designing it.

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For this reason it is thought appropriate to develop a suitable mechanical

transmission system which when subjected to a continuously varyingspeed of input, will give approximately constant output speed over anestimated range of variation in input speed.

Fig. 2.1 (a) : Constant output drive for variable input, using gears rolls

Fig. 2.1 (b) : Constant output drive for varying input, using friction rolls.

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Fig. 2.1. (a) Shows conceptual design of the drive using gears. Flywheel

fixed on shaft A is spun to a predetermined speed through input gear 2.Machine elements 3, 4 (four identical links), 5(two identical balls), 6 forma flywheel speed sensor. Link 3 is fixed to shaft A. Element 6 and gears

7,8,9 are keyed to sleeve 10, which is mounted on shaft A with feather

key.

It is proposed to design pitch circle diameters of gear wheels, such thatthe minimum of speed deviation in the speed of output shaft B will bemaintained.

Upon engaging the clutch 14, flywheel is immediately subjected to a loadtorque, because the drive is so arranged that gear pair 7, and 13 arealready in engagement when the clutch 14 is engaged.

As the flywheel is subjected to the load, it will be immediately subjectedto speed fall. On account of this speed fall, spring 15 will be in a positionto move the sleeve rightwards, pushing the gear cluster 7,8,9 towards

right. The spacing of gears 8,9 on sleeve 10 will be so adjusted that asthe gear cluster continuously moves towards right, the engagement of

gear pair 8-12 and 9-11 will take place in such a way that the fluctuation

in speed of output shaft B will be achieved to be minimum.

Fig. 2.1. (b) Shows a conceptual design of the drive in which the gears of

the drive discussed in Fig. 2.1(a) are replaced by friction rolls 7 and 8.

Friction roll 7 is cylindrical and mounted on sleeve 10. Friction roll 8 isconical and is mounted on shaft B, which is connected to process unit

input shaft. As the speed of the flywheel drops, the compressed spring

pushes the rotating roll 7 rightwards to slide on shaft A.The contact radius of cone 8 keeps on reducing for different positions of

roll 7, such that with continuously reducing speed of input shaft A, shaft Brotates at a Constant speed.

Comparision of Operational Characteristics of the Drives

Although it is from the Kinematics of the drive with friction rolls, thatspeed of output shaft is expected to remain fairly constant, it has onesignificant shortcoming, that this drive is dependant on friction traction

between the cylindrical roll and the conical roll. It is very essential toachieve very high wear resistance for the surfaces of these rolls in orderto get desired performance of the drive for a very long time. It is in this

respect the drive with gears is better.

It is therefore suggested that the first drive should be the first preference,provided the process machine operational characteristics permit somedeviation in the shaft speed.

However if the operational characteristics of process machine cannot

permit even the smaller deviation in the speed of shaft B, then the choiceshould be the second drive, although it may turn out to be somewhatcostlier compared to the first drive.

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2.3 Improvement of Cranking Arrangement

Cranking arrangement of bicycle is one component of HPFM. This actuallycomprises a five linkchain. Heap joint to peddle axle is a fixed link or aframe, thigh is an oscillating input link, leg (distance between Knee joint

to ankle) is a coupler, foot and peddle is the output link. Though it is a

five link chain it is a constrained chain because the orientation of thigh

and position of foot with respect to the leg is decided by nervous system.However, this five link chain can be approximated to a four link chain by

eliminating foot as a separate link.When it comes to improve HPFM it becomes necessary to improve the

performance of this cranking arrangement too. Hence, Kinematic Analysisof existing mechanism was done [16] to examine its shortcomings if any.For every configuration of this mechanism unit force application throughthe leg is assumed and torque generated at the small sprocket isestimated.

The static force analysis [16] revealed that (1) about 30oof crank travel isthe idle period (2) about 110o is less effective period (3) only 220o is ausefully utilized period.

These shortcomings prompted us to design several new crankingarrangements such as (1) Quick Return Ratio (Q.R.R.) = 1 drive (2)Doublelever inversion drive. These are 17% and 35% more effective ascompared to the existing (Figs 2.3 (a) & 2.3 (b)). This effectiveness isconceptualized as the ratio of energy delivered at small sprocket with a

proposed new drive to the energy delivered at small sprocket with existing

drive in the same duration. This effectiveness is nominclated as ME. ThusME for Q.R.R.=1 drive is 1.17 where as that for double lever inversion

drive is 1.35. Literature indicates [58] use of Elliptical Sprocket instead ofpresently used big sprocket. Its ME value has come out to be 1.18 [16].

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Figure 2.3 (a) : Bicycle Cranking Mechanism QRR = 1 Drive

Figure. 2.3 (b) :Double Lever InversionModak & Moghe [19-22, 64, 65] have proposed several other cranking

arrangements. The experimental validation of some of these are alsoexecuted [17, 18, 64, 65]. The Double lever inversion drive is proved tobe the best though it is complex & costly from the fabrication point of

view.

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3.0 GENERATION OF THE DESIGN DATA FOR HPFM THROUGHESTABLISHMENT OF THE GENERALISED EXPERIMENTAL

DATA BASED MODELS

3.1 Necessity of Experimental Data Based Models

Design data for a Human Powered Flywheel Motor was not available whenMHADA machine was developed. The main parameters of this sub-system, namely bicycle drive mechanism, speed rise ratio between smallchain wheel shaft and flywheel shaft and mass moment of inertia of theflywheel were decided based on intuition and easy availability of

components. That time it was not known whether these are the optimumchoices to achieve any one of the below stated objective functions.1. To get maximum angular velocity of the flywheel at the end of

stipulated peddling time.

2. To get maximum energy stored in the flywheel at the end of stipulatedpeddling time.

3. To achieve maximum efficiency of conversion of human muscularenergy into rotational kinetic energy of the flywheel.

Such optimisation is possible provided the mathematical models amongstthese parameters are established.

It is highly improbable to evolve such models adapting total theoreticalapproach of applying one or more of basic balances of mechanics, viz. (1)Force balance (2) Momentum balance (3) Energy balance (4) Massbalance [63]. This is so because the phenomenon of energy conversion inthis case of man-machine system is highly complex for applying these

balances.

Hence an approach of methodology of experimentation [55] is adapted toevolve Generalised Experimental Model for this man-machine system. Inthis approach all independent parameters are varied experimentally overwidest possible range and the response data is measured. Based on thisexperimental data the analytical relationship amongst independent anddependent parameters is established. Thus, the desired Generalised

Experimental Model is established. This has revealed the optimum valuesof the independent parameters to achieve various above stated objectivefunctions.

3.2 Planning of Experimentation

The dimensional equation for the process is deduced as follows:WT = f [(I/RT2), (ME), (G)] (3.1)Where,

W = Angular Velocity of flywheel in rad/sec reached after timeinterval T secs.,

I = moment of inertia of flywheel, Kg-m2

R = energy input by rider, Kgf-mME = effectiveness of mechanism, MG = speed increasing gear ratio

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f = stands for function of

T = peddling time, in second.

Table 3.1 enumerates Test envelope, Test points and Test sequence [55]

for every independent term or parameter which have been worked out

based on earlier findings [1 and 16 18]. It is not possible to estimate

Test envelope for (I/RT2

) because it is not possible to adjust R for thegiven rider. Hence Test envelope for parameter I only is considered.

Table 3.1 : Test Envelope, Test Points and Test Sequence

Sr.

No.pi Terms Test Envelope Test Sequence

1. I Moment of Inertia

of Flywheel, kg-m20.255 to 3.48 (for I) 0.255,1.867, 3.48,

1.061, 2.673

2. ME Effectiveness of

Mechanism M1 to 1.18 1, 1.17, 1.18

3. Gear Ratio 1.14 to 4.0 1.14, 1.5, 4.0, 2.0, 1.3

The different bicycle mechanisms developed by Modak [16] other thanexisting bicycle mechanism are i) Quick Return Ratio = 1 drive and ii)

Double lever mechanism. The Elliptical drive mechanism [58] is alsostudied. It is found theoretically that effectiveness of Q.R.R.=1 drive,Elliptical drive and Double lever inversion is respectively 17%, 18% and

35% more effective as compared to existing drive from the point of viewof riders energy utilization [16]. Hence in TABLE 3.1 the test envelope istaken as 1 to 1.18 for ME in view of the fact that in the present

investigation only three mechanisms viz. (1) Existing (2) Q.R.R.=1 driveand (3) Elliptical sprocket drive [58] are tried. Double lever inversion,

although should have been tried in spite of the fact that its ME value is1.34 could not be tried at this stage because of its mechanical fabrication

complexity.

The physical design and fabrication of the experimental set up was thencarried out [6 & 7] and the set up was tested for sturdiness, accuracy and

smooth running [8]. A procedure is evolved [9] for eliminating the effectof extraneous variables associated with rider like temperament, attitude,day and duration of test etc. on the experiment.

The complete set up is described in details in Fig. 3.1.

Figure 3.1 : Experimental Set-Up for Human Powered Flywheel Motor

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3.3 Analysis of the Results

From the observations taken the graphs are plotted to indicate the systemresponse (average for all riders) while varying G, ME and I in morning,noon and afternoon. The average of these readings obtained in morning,

noon and afternoon are taken and the graphs are plotted as (i) WT

average Vs G, Fig 3.2, (ii) WT average Vs ME, Fig 3.3 and (iii) WT

average Vs I, Fig 3.4. Qualitative discussion regarding variation in thedependent pi term WT as resulted because of variation in independent pi

terms G, ME and independent parameter I is presented.

Figure 3.2 : Log WT Verses Gear Ratio, G

Figure 3.3 : Log WT Versus Effectiveness of Mechanism,ME

Figure 3.4 : Log WT Vs Moment of Inertia, I

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3.3.1 Qualitative Justification of Results

Assuming more or less same frequency of pedaling for all the riders it isexpected that WT must increase if G is increased. Since the pedaling timeT is kept same for all the observations as G is increased, effectively

angular acceleration of flywheel shaft has also increased. This will result

into greater inertia torque, as I is kept fixed. This increased inertia torque

on the flywheel shaft with increased G has further increased torque onpedals, which is to be overcome by the rider. This means with increased G

the energy input by rider (R) must also increase.

If R Vs G is plotted then the agreement between WT and R can be

reasoned out. Likewise, variation of R Vs ME and I is also needed forcomplete justification of the results. As this is a first attempt in this areaso much detailing is postponed as further work. Thus relationship WT Vs G

should apparently be linear. However, the different slope values areobserved in Fig 3.2 for different values of G. This indicates that thephenomenon of energy release in human body is highly complex as theload on the limbs changes. The complexity of this phenomenon all the

more justifies the experimental solution of the phenomenon.

3.3.2 Mixed Plan-Character of Present Experimentation

The classical experiment [55] was planned to obtain the generalised

empirical relationship of a human powered flywheel motor. In this type ofexperimentation, at a time one independent pi term is varied and thereflections on the dependent dimensionless group are observed. In thisexperiment independent pi term, which is to be varied, are (I/RT2), (ME)

and (G). The dependent pi term is (WT). Accordingly, an attempt is madeto vary each independent pi term at a time while maintaining otherindependent pi terms at constant desired level and noting the effect on

dependent pi term i.e. (WT). However, it is observed that this type ofexperimentation is only possible while varying (I/RT2) in which case MEand G could be held at constant desired level. But, while varying ME or Git is observed that (I/RT2) is however known for every observation. This isbecause of the fact that variation in R even for the same rider and for

unchanged other physical condition is highly unpredictable and dependson various extraneous variables like his physical condition, environmental

condition, psychological factors like enthusiasm, interest etc. In fact

different riders of a particular age group are chosen to average out theeffect of their extraneous variables. The readings were taken on different

days and during different time i.e. morning, noon and afternoon to

average out the effect of extraneous variables, shift day and time [9].

Still, it is observed that (I/RT2

) cannot be maintained at fixed levelbecause of uncontrolled variation in R.

Thus as far as this type of experiment is concerned where human energyinput is involved the plan of experimentation will be either classical or

factorial. Thus a mixed plan is the characteristic of such a situation. Thiscan be considered as a general characteristic of a man-machine system.

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3.4 Generalized Experimental Model

Assuming the exponential form for the dimensional equation of thisprocess, Eqn 3.1 takes the form

WT = K (I/RT2)a(ME)b(G)c (3.2)

Where K is a curve fitting constant and a, b and c are constant exponents.

Using the multiple regression analysis based on experimental data and

appropriate computer program. The values of K, a, b and C are obtainedas 1.288, -0.46, -0.87 and 0.40 respectively. This deduces the generalisedexperimental model for this human powered flywheel motor as

WT = 1.288 (I/RT2)-0.46(ME)-0.87(G)0.40 (3.5)

3.5 Optimization of I, ME AND G

It is clear that the objective of establishing this experimental model for

this flywheel motor is ultimately to optimise it for various applications ofthis flywheel motor. Obviously, the application could be such that forsome it may be desirable to achieve highest possible flywheel speed at theend of pedaling or storing maximum possible kinetic energy in theflywheel at the end of pedaling or for getting maximum efficiency for thisenergy conversion process.

For some processes it may be necessary to optimise the combination ofabove enumerated objectives.

The analysis which follows now, discusses how to optimise establishedmodel for:

i. to achieve maximum WTii. to achieve maximum stored energy in the flywheeliii. maximum efficiency

3.5.1 Optimisation of Maximum Wt

From the Eqn (3.5) it can be concluded that for obtaining maximum valueof WT term (I/RT2) should be minimum as its exponent is having anegative value. Similarly, the exponent of (ME) is also having negative

value. Therefore, standard bicycle mechanism having ME = 1 should onlybe used to achieve maximum value of WT. The exponent of G is having

positive value, which indicates that value of G should be maximum, toachieve maximum value of WT. In the experimentation maximum value ofG is 4.

Thus to achieve maximum value of WT this man-machine system shouldhave I = 0.255 kg-m2, ME = 1 and G = 4.

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3.5.2 Optimisation for Maximum Energy Storage

The other aim of experimentation could be to decide the systemparameters to achieve the maximum energy storage in the flywheel. The

energy storage in the flywheel is given by

E = 0.5 * I * 2 (3.6)

From Eqn (3.6) one may apparently conclude that E will be maximum

when I and both are maximum simultaneously. However, from theexperimental data it is observed that is maximum when in fact I is

minimum. Thus as energy storage is dependent on second power ofthenecessary condition for E to be maximum is when is maximum. Hence,the necessary values of the parameters for getting maximum energy

storage are I = 0.255 kg-m2, G=4 and ME=1.

For the complete observed data of the 250 observations the envelope ofinput and output energy is obtained as described in Fig 3.5.

3.5.3 Optimisation for Maximum Efficiency

Similarly, for obtaining maximum efficiency it is observed that the systemshould have G = 2 or 4, ME=1 and I should be in between 0.255 to 1.061kgf-m2.

Figure 3.5 : Energy Output Vs Energy Input

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A further detailed experimentation is required to find out the exact values

of G and I so that maximum efficiency can be obtained.

3.5.4 Optimisation for Effective Peddling Time

The graph on X-T plotter (Fig 3.6) is plotted for rpm of flywheel Vs time

and simultaneously the air consumption of rider is noted. It is clear fromEqn 3.9 that approximately after 40 seconds the graph starts flatteningand becomes approximately parallel to time axis. Thus it is clear that thepedaling is required to be done only for about 40seconds and not for 60seconds as is done in experiment.

This is one of the major findings of the experimentation, which puts a limiton time of operation of pedaling.

Now, to find out the actual efficiency of the system it is necessary tomeasure the air consumption during these 40 seconds only. For gettingthis and for finding actual time of operation a further experimentation is

necessary.

3.5.5 Conclusion

Generalised experimental model for a manually driven flywheel motor isdeduced with below mentioned limitations:

1. The optimisation of the independent parameters of the process isdone for achieving singular objective (i.e. to optimise for maximumWT, maximum energy storage in the flywheel or maximum

efficiency).

Figure 3.6: Flywheel Instantaneous Speed Vs Pedaling Time

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2. Ergonomical aspect such as posture is not considered while finding

out efficiency of the system.3. The rate of energy storage and rate of energy input is not

measured.

4. Only leg operated mechanisms are considered. Hand operated may

also be given a thought.

5. Concept can not be used for continuous operation.6. The operation time is not fixed for getting maximum efficiency.

7. The process can be used where power requirement is up to certainlimit (i.e. h.p. of system is up to a certain limit only [1 & 4]).

Different types of riders are not considered for establishing themodel.

3.6 Formulation and Optimization of Models for Variousefficiencies

3.6.1 Scope of present research

As an extension of earlier mathematical models [10], some more modelsare formulated for the response variables of the energy unit, such as thetransverse force exerted on the pedal, the crank, pedal, and foot positionswith respect to the frame, the pedal and flywheel energies [14]. This

extension essentially reports on experimentation which involves describing

and varying independent variables, the method of measuring the responsevariables, the procedure of experimentation, data collection, presentation,

and analysis, concluding with a qualitative logical analysis for theoptimization of the models.

3.6.2 Experimentation

Independent variables

Independent variables chosen this time are more or less same as that ofearlier investigation [10] except (1) Double lever inversion having ME =1.38 was also tride this time and (2) Twelve male riders in an age group

of 20-22 years and of slim stature were chosen for the experiments asagainst 4/5 tried earlier.

The load torque required to be overcome on the flywheel shaft is I.a,where a is the average angular acceleration during the pedaling duration

of one minute. The load torque to be overcome on the pedals is thereforeG.I.a. The total air exhaled during experimentation was recorded by a

specially-designed and fabricated spirometer [12, 13]. The specialty ofmeasuring the exhaled air with respect to time is an improvement over

the earlier investigation [10]. The total (physiological) energy input bythe rider is estimated from the exhaled air collected in the spirometer andthe corresponding oxygen intake.

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Dependent variables

Ft, the transverse force exerted on the crank, is measured using strain

gauges which are mounted midway on the cranks. The instantaneous

strain values are stored in a computer memory for further processing.The crank angle is measured digitally by using a circular ring having

equally spaced drilled holes and a photoelectric sensor which measuresthe interruptions of the light beam as the ring rotates. The pedal energy

is estimated in terms of the pedal force Ft, the circumference of the pedalrotation, and the number of rotations of the pedal during the period ofpedaling. The flywheel energy is estimated in terms of I (the flywheelsmoment of inertia), and the terminal flywheel speed which is measured asearlier by a techometer. An X-T plotter gives the graph plot of the

instantaneous flywheel speed during the period of pedaling.

3.6.3 Conduct of experiment

Experiments were conducted while varying ME, I and G independently. Alltwelve riders operated the system for every combination of ME, I and Gand the values of the corresponding independent and dependent variableswere recorded.

Figure 3.7 : Instantaneous Ft Vs Crank angleFigure 3.7 describes the variation of instantaneous Ft vs. crank angle for

both the legs for one cycle of operation of the pedal crank. (Here the

result is the average of 3 riders from the 12, chosen at random). Thetotal average Ft is 38.8N and during one minute an energy of 2616 Nm isaccumulated, thus the average power here is about 44W. I is given as0.225 kgm2 and G is given as 1.5.

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Figure 3.8 : Ft, R and Flywheel load torque Vs I, averaged over 1

min

Figure 3.8 presents the measurements of some physical quantities versusI (average values from the 12 riders). These are the energy input R, thetransverse pedal force Ft and the flywheel load torque, all averaged overthe pedaling duration of one minute. G is given as 2.0.

Figure 3.9 : Energy efficiencies measured at the end of 1 min. pedalling duration

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Figure 3.9 presents the variations of pedal energy and flywheel energy at

the end of the one-minute pedaling duration versus I, given as percentageof the input energy (average values from the 12 riders). G is given as2.0.

Findings of this investigation and corroboration of generalised

experimental models reveals the best combination of variables to use for aspecified objective function, e.g., if the objective is to minimize pedal

force FT, the smallest available values for I and G are to be used.However in terms of efficiency, as seen in figure 3.9, the combination I =

1.06 and G = 3.8 is optimal. In terms of maximum power, as seen infigure 3.8, the same combination very nearly gives the maximum flywheeltorque, and hence maximum flywheel power (neglecting flywheel loses).The generalized mathematical model however gives different optima forefficiency when the variable in question is I, and the authors conclude that

for this case more experimental evidence is needed in order to understandthe relationships.

3.6.4 Conclusion

There exists a considerable similarity in this investigation and of previousinvestigators [59] regarding the pattern of transverse force Ft exerted onthe pedal at every instant during the cycle of each leg. There has beensome difference in the pattern of Ft for both the legs during the rise of Ft

compared with the previous investigations. This needs to be confirmed by

additional research. It is not desirable to keep the flywheel moment ofinertia I in the range of 1.4 to 2.4 kgm2. This is because during this

variation of I all the three parameters R, Ft and G.I.a have fairly largevalues.In view of keeping internal human body energy losses and frictionalenergy losses at a minimum, it is necessary to keep G at 3.8 and I at

1.06 kgm2, however lowering G to 2.85 or even 2.17 may result in areasonable compromise between the intensity of taxing muscles and

incurring considerable internal physiological energy loss in the human

body.

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4.0 GENERATION OF DESIGN DATA FOR THE TORSIONALLYFLEXIBLE CLUTCHES THROUGH ESTABLISHMENT OF

THE GENERALIZED EXPERIMENTAL DATA BASEDMODELS

4.1 Necessity of Positive Torsionally Flexible Clutches

During the period of clutch engagement the mechanical system issubjected to severe shock due to instantaneous momentum exchange.On account of this, spiral jaw clutch is subjected to unpredictable

malfunction. This is one of the serious drawbacks of this system.The basic reason for the spiral jaw clutch failure is, it does not havetorsional flexibility very much needed in this situation. A clutch with

torsional flexibility will permit momentum exchange at a slow rate. Theexhaustive literature survey [60,61] shows that clutches with torsionalflexibility are not developed excepting the attempts of Modak and hisresearch scholars [25-32, 34-37, 66]. These types of clutches permitmomentum exchange at a fairly slow rate. Though literature indicatesdevelopment of plate clutches with axial flexibility [60, 61] these are not

useful for the present purpose.

4.2 Types of Torsionally Flexible ClutchesThree types of torsionally flexible clutches [25-28] are conceived anddeveloped. These are Finger type, Face Tooth Type and Toothed GearType [25-28].Finger type torsionally flexible clutch:Clutch comprises of two members. Member 1 is connected to the flywheel

shaft through splines. Multiple number of fingers 3.4.6 are provided

integral with the hub of the member 1. Fingers have rectangular sectionas shown. Member 2 is carrying jaws J (3.4.6 depending on number of

fingers provided) but number of jaws equals number of fingers Member 2is integral with the jaw which provides drive to the process unit.

Figure 4.1 : Schematics of Finger Type Clutch

Fingers F, structurally behave as short cantilevers having spring like

action because of its elasticity. Thus the fingers provide relative angulardisplacement between load shaft and the flywheel shaft during the periodof clutch engagement. This is how torsional flexibility is provided by thistype of clutch.

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Figure 4.2 : Face Tooth Clutch

The Clutch is described in Figure 4.2 The Clutch is consisting of twoidentical parts A and B having four jaws on their end faces. B is rigidly

fixed to the load shaft while A is mounted on flywheel shaft. A canperform an axial movement by virtue of splines and bush with zerorelative angular rotation with respect to flywheel shaft. The axialmovement of A is initiated with the help of shifting lever.

Toothed Gear Type clutch:

The clutch is described in Figure 4.3. Two toothed gears A and B are

keyed to the flywheel shaft and the load shaft respectively. The ring gearC with the same number of the teeth as on A & B meshes with A. C is

made to slide axially on A in order to engage with B.

Figure 4.3 Toothed Gear Type Clutch

4.3 Models for Finger Type Clutches

The present research [30-31] addresses to the generation of design data

through the development of generalized experimental model for a fingertip load and subsequent vibrations of fingers in a finger type torsionallyflexible clutch.

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Dynamics of the clutch

Clutch engagement duration is defined to be the time interval in which the

flywheel shaft and the load shaft attain the identical speeds after first

contact of fingers with the jaws. During this period, flywheel shaft speedF & load shaft speed L are different. Applying De-Alemberts

formulation, the general conditions of dynamic equilibrium for the flywheelshaft and the load shaft respectively can be derived as

-IFF bFF Kt = 0

.(4.3.1)Kt-ILL bLL TL = 0

.(4.3.2)

In Equs (4.3.1) & (4.3.2)IF & IL are moment of inertias of flywheel andload shaft. bF and bL are bearing Friction Torque Constants of Flywheeland load shafts respectively, TL = Load Torque on the load shaft asimposed by the process resistance. K = Stiffness of the fingers t

instantaneous slope of the finger at its fixed end, W = Finger Tip Load.Careful Examination of Equs (4.3.1) & (4.3.2) shows that these equationsare not solvable unless experimental feedback of the behavior of thesystem is known.

Hence, it amounts, to establishing the generalized experimental databased models for F & L or eventually of finger-tip load & finger

vibrations which can be considered to be a function ofF &L.

Design of Experimentation

Generalized Experimental Models for W & S (Maximum Stress Induced in

the fingers due to finger vibrations) are established adopting methodologyof experimentation [55].

Dimensional Equations

Applying Buckingham II theorem & Releighs method [55] the

dimensional equations for (WD/TL) & (SD3/TL) are Formulated as under.

WD / TL=f [IF/TL*t2), (IL/TL*t2), (bF/TL*t), (bL/TL*t), (R/D), (w/D), (d/D),

(ED3/TL), (U), (N), (gt2/D)

.(4.3.3)

SD3/TL = f [IF/TL*t2), (IL/TLt

2), (bF/TL t), (bL/TL t), (R/D), (w/D), (d/D),(ED3/TL), (U), (N), (gt

2/D)]

.(4.3.4)

Lete R = Radius of the circle described by tip of the finger

W= cross sectional dimension of the finger transverse to the shaft axis,

d = cross sectional dimension of the finger parallel to the shaft axis, D =

2R, E = Modulas of Elasticity, U = coeff of friction, N = number of fingers.

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Test Planning : Keeping in view the functional response obtained inprevious investigations [26-28] & in view of cost, time and computationalaccuracy constraints the test planning is decide as described in Table 1.

TABLE 4.1 : TEST PLANNING

Term Test EnvelopeWD/TL 34.5 21.7

IFTL/ t2 107.29 42916.8

ILTL/t2 0.909 363.7

IFis held constant, ILis varied over TLis varied over For some terms the

test planning could not be done as time (t) gets associated with the

term.

Experimental Set up

Fig. 4.4 describes the experimental set up having the provision of varying

all independent terms of equations 4.3.3 & 4.3.4.

A band brake is arranged to vary TL. Encoders EFand ELput on flywheelshaft & load shaft respectively generate signals representing F& Lare

further processed through frequency voltage transducer using ICs andvoltage output is fed to the PC using A-D converter. PC gives graphicdisplay of F& Lverses time. A representative variation is depicted inFig. 4.5.

Figure 4.4 : Experimental Setup

Generalized Models

Using the principle of (i) force balance & (ii) energy balance variation of W

verses time is established as depicted in Fig. 4.6 by the curves (a) & (b)respectively corresponding to the experimental data of Fig. 4.5.

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Figure 4.5: Dynamic Response

Fig. 4.6 shows erratic variation of W. This appears to be because of

unpredictable bearing friction torque. This situation may be perhaps dueto much more severe loading on the flywheel shaft & load shaft. Hencehereafter the anticipated finger tip load based on force balance concept isno more considered. The vibration response is evaluated approximatingthe finger as a single degree of freedom spring mass damper system,

is assumed to be 0.9 in view of the fact that the system damping is dueto the friction between the finger and the jaws due to axial siding of

fingers under sever tip load during the period of engagement is not

reflected in equs I & II. To account for this, is assumed to be very highand of the order of 0.9.

Fig 4.6 Variation of Load (W) with Time (t)

Fig. 4.7 shows the variation of maximum stress vs time for the variationof W Vs time shown in Figure 4.6 (a) & 4.6 (b). The above variations areobtained for the entire experimental information gathered in this work.

Based on this research, exact mathematical form of dimensional equation(4.3.1 & 4.3.2) are obtained after performing necessary mathematicaloperations & are reproduced below.

WD/TL = -0.063 [IF/TL*t2)1.569 (IL/TL*t

2)-0.07 (Rwd/D3)-0.031 (ED3/TL)-0.237

(gt2/D)1.512]

(4.3.5)

SD3/TL= 0.1438 [IF/TL*t2)0.0027 (IL/TL*t

2)0.0289 (Rwd/D3)0.2766 (ED3/TL)0.0638

(gt2/D)-0.128]

(4.3.6)

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Figure. 4.7 Stress under vibration Vs Time

Computer programmes are developed for complete quantitativeprocessing of experimental information.

Discussion of Results

Fig. 4.5 shows that in the early part of clutch engagement there is a dropin flywheel speed but afterwards it keeps on increasing till t = t3when F= L. Lhowever keeps on increasing right from t = t1till t = t3with somespells of time in which f is negative. Similar behavior is observed for

entire variation of independent quantities.

This indicates that immediately upon colliding of fingers on the jawsconsiderable energy is stored in the finger in the form of elastic strain

energy. Maximum energy should be stored during t=t2-t1. In fact thisgets confirmed from subsequent calculations of estimation of finger tip

load W. Curve a of Fig. 4.6 shows maximum W at t=t2 when F is

minimum. As W is maximum at t=t2tip deformation is maximum at t = t2hence is the maximum storage of strain energy. Interestingly, it isobserved that duration t=t2-t1varies with system independent variables.In fact generalized experimental model should be formulated for t which

will reveal the influence of independent quantities ont & hence an impact

phenomenon.

Further interesting observation is at times L is + ve and at times ve

during t=t2-t1. This solidly confirms that load shaft at times demandsenergy from fingers and at times pumps the energy in the fingers. Thisshould cause severe superimposed oscillations over and above that

caused by variation of W verses time. Finger vibrations during t=t3-t2also during t=t2-t1 as W is rising with steep gradient, fingers are

subjected to transient vibrations. On the whole therefore fingers aresubjected to vibrations which needs estimation of stress under vibrations.

Equs. 4.3.5 & 4.3.6 reveals that as the index of term (IF/TL*t2) is

maximum. Stress under vibration is highly sensitive to IF, TL, t.

Curve a of Fig. 4.6 shows higher value of W as compared to those of curveb. This is obvious because frictional energy loss is not assumed for

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information represented by curve a. Bearing friction phenomenon appears

to be pretty erratic because curve b shows W = 0 for some instants. Thisis because at those instants frictional resistance it self is enough toimpose necessary retardation heaven if not reaching to limiting value of

friction.

The experimental set up may need additional instrumentation to solidlyascertain the influence of friction.

In the estimation of vibration response over simplifying assumptions are

made which are as under (I) Entire finger mass is assumed at tip (2)finger elasticity is assured to be linear. In fact it may be non linearleading to the sever finger oscillations (3) is assumed to be = 0.9 a very

high value without which stress under vibrations could not have been apractically acceptable figure, = 0.9 may be justified because

considerable axial frictional rub of the fingers during t=t3-t1 is not

modeled. It is necessary to crystallized its influence. Of course this willbe only possible by sophisticated instrumentation like telemetry.

Conclusion

Although the formulated generalized experimental models are useful fromclutch design point of view, the models need to be refined by collectingthe experimental data adopting more sophisticated instrumentation.

4.4 Approximate Generalized Experimental Models ForTorsionally Flexible Clutches

J.T.Pattiwar at all [32, 66] established these models in a limited way.The limitation was by only varying ILinertia of process machine and the

load torque TL.

Huge experimental data is generated for these types of clutches to

investigate the dynamic response based on the experimental data.An approximate generalized experimental models [55] for these clutchesbased on this experimental data are established as under.

F*t) = 1.2537 [IF/TL*t2)-0.3877(IL/TL*t

2)-0.0048] (4.4.1)L*t) = 2.4020 [IF/TL*t

2)-0.8621(IL/TL*t2)-0.1024] (4.4.2)

F*t) = 0.9586 [IF/TL*t2)-0.3648(IL/TL*t

2)-0.0772] (4.4.3)

F*t) = 1.9866 [IF/TL*t2)-0.8642(IL/TL*t2) 0.0961] (4.4.4)F*t) = 1.0043 [IF/TL*t

2)-0.3929(IL/TL*t2)-0.0536] (4.4.5)

L*t) = 1.1498 [IF/TL*t2)-0.7206(IL/TL*t

2)0.05278] (4.4.6)

Equations 4.4.1 to 4.4.6 are the approximate generalized experimental

models respectively for Finger Type, Face Tooth Type & Toothed GearType torsionally flexible clutches. These are approximate generalized

models because the geometrical and material parameters of the individual

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clutches (except for Finger type clutch) are not varied in the present

investigation.

The curve fitting constants 1.2537, 0.9586, 1.0043 (for flywheel shaft) &

2.4020, 1.9866, 1.1498 (for load shaft) represents the geometrical and

material properties of the respective clutches. The model is useful from

the point of view of estimating the dynamic response for known values ofmoment of inertia of the load, moment of inertia of flywheel and load

torque. The models are valid for the ranges of variation of terms(IF/TL*t

2) & (IL/TL*t2) as detailed in Table 4.2

Figure 4.8 Dynamic Response of various clutches

Table 4.2 : TEST ENVELOPS OF INDEPENDENT TERMS

Sr. No. Clutch Type IF/TL*t2 IL/TL*t

2

1 Finger Type Clutch 37.125 to 201709.4 0.5005 to 23669.69

2 Face Tooth Clutch 240.73 to 1573.33 1.0732 to 47339.38

3 Tooted Gear Type Clutch 16.18 to 403418.8 0.1279 to 47339.38

Analysis of Results

The experimental performance of the three types of clutches as describedin Figure 4.8 is qualitatively discussed as follows

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Performance of Finger Type Clutch

Referring to Figure 4.8, it is evident that in the duration t = (t2 t1)

there is a considerable storage of strain energy in the fingers. This is so

because in the duration t = (t3-t1) both the shafts are accelerating.Looking to the smooth variation of L it establishes that the Finger Type

Clutch has maximum torsional flexibility. The maximum relative angulardisplacement between flywheel shaft and load shaft for the entire range ofvariation of IL & TL is observed to be 2.8

o. Although this reasonably

indicates that the instrumentation is satisfactory, actually it is not so if the

area intercepted between F Vs Time & L Vs time is considered. Thisarea comes out to be much more than maximum (F - L ). This shows

that the measurement system should be further improved.

Performance of Face Tooth Type Clutch

In the entire duration of clutch engagement more or less there is acontinuous decline in F and there is a continuous rise of L .The area

intercepted between the two curves F & L indicates permissible torsionalflexibility. In act this area should be much smaller as compared to thesame for Finger Type clutch. This could be probably due to (1) slowresponse of electronic measurement system & (2) partly due to theclearance between the tooth faces.

Performance of Toothed Gear Type Clutch

The variation of F Vs Time shows continuos decline of F & L Vs Timeshows steep variation meaning there by much higher angular accelerationof the load shaft as compared to earlier two types of clutches. During

certain spell of time of clutch engagement period sudden rise and fall in

L could be reasoned out towards the prevailing backlash between theteeth.

Conclusion

Operational sensitivity of the clutches from the point of view of indices ofvarious independent terms can be stated as follows.

1. As the range of indices for (IF/TL*t2) is in the range -0.3648 to -

0.3923 and that for the term (IL/TL*t2) is in the range -0.0048 to -

0.0772 it is concluded that the dynamic response is highly sensitive

to load shaft inertia.2. The three curves of Figure 4.8 clearly ranks Finger Type Clutch, Face

Tooth Clutch, & Toothed Gear Type Clutch in the descending order of

torsionally flexibility.3. It is very necessary to improve the accuracy of electronic measuring

system.

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5.0 APPLICATIONSThere are several processes essentially rural based where power requiredis moderate (2-5 hp) and which can be of intermittent nature. Hence, thisconcept of HPFM is applied. What follows are these details for some

processes.

5.1 Water LiftingA tillu water pump of small capacity 4m lift and 1m3/10 minutes has beenoperated by such a Human Powered Flywheel Motor [62]. In 5/6energisiation of flywheel this much quantity of water is lifted through 4mheight. The concept is very useful for low head irrigation purposes forsmall farmers.5.2 Bricks Manufacture

After initial version of MHADA machine for rectangular bricks, tworesearch projects were completed. In one generalised experimental data

based model was formulated for extrusion of rectangular bricks [38-44]and confirming feasibility of manufacture of keyed bricks [45-49] (Fig.5.1). The productivity is enhanced to average 16 bricks/minute. Back

pressure flow and leakage flow is reduced by putting ring at the end andchanging the geometry of last blade of auger (Fig. 5.2 (a), (b), (c) ).Twine mould concept extensively enhanced effective utilization of flywheel

energy.Technology is evolved for de-molding bricks with such a complicatedshape of cross section after many trials (Figs. 5.1(b) to 5.1(f)).

Keyed bricks have special advantage of practically morterless journey ofbricks. Subsequently generalised experimental data based models forkeyed bricks are also established [45-49].

Figure 5.1 : Keyed Bricks Demolding process

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5.3 Algae Manufacturing

5.3.1 Basic Requirement

This is a rural requirement of production of spiraling algae. A drum (60cmlength x 30cm dia.) is rotated in a tank of water for the purpose of (1) to

brake algae and (2) push the water ahead. Water then passes throughcanal and comes back to the centrifugal drum.

Figure .5.2 : Mechanical Design Modification to increase Clay

Flow

5.3.2 Earlier System

One such system was available at CSV, Wardha (Fig. 5.3(a)) [53]. A

stone weighing 350 kgf was raised though 6m height by hand crankingonce in a day. The transmission comprised of series of chain drives(speed ratio 4.3:1). Algae drum could be rotated at 12 R.P.M. speed.Uniform speed of rotation was possible by perhaps excessive frictional

resistance offered by transmission. System did not have properalignment. Production capacity was 1 kg of algae per day.

This system had lot many problems (1) frequent falling out of chains (2)350 kgf weight dropping (3) difficulties in repairs. One had to rely on

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cycle repairer. This task was not profitable to them. It used to create

excessive strain on hands while lifting. Higher speed could not beobtained.

Figure 5.3 (a) : Schematic Representation of Existing System

5.3.3 New Design

Concept: Using H.P.F.M. raise 45 kgf weight, energizing system 8 timesa day. This should supply the same energy to the system as it used to bewith earlier arrangement. This should give 20 RPM speed of the drum.Use gears instead of chains.

Details: New design is so evolved that flywheel could be speeded to 320

rpm in 1 minute. Finger type torsionally flexible clutch is adopted.Weight is raised through 6 m using rope drum as shown (Fig. 5.3(b)). A

self locking brake is provided on drum shaft responsible for uniform

rotation of drum at 20 rpm.

Fig.:5.3 (b) Manually Energized Drum Type Algae Processing Unit

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5.4 Types of Manually Energized Machines

There are three types of Manually Energized machines [54].

Type 1: Power demand far in excess of continuous duty human capacityof 0.13 hp. This needs flywheel and hence H.P.F.M. Possible applications

could be water lifting, bricks making, threshing, food grains crushing,Chauf cutting etc.

Type 2: Power demand same as that of human capacity continuous duty.Possible applications could be winnowing, wood strips cutting, algaemanufacturing etc.

Type 3 : Power requirement same as that of human capacity but cyclicspeed fluctuations are not desired. A small fly wheel is desired in suchcases.

5.5 Winnower

This machine belongs to Type 3 given above [ 54 ].MIXTURE OF FOOD GRAINS & HUSK

Fan

--------------X------------X-------------- ---------------

CH2 F

Grains

--X--------X--

F = Fly WheelCH1, CH2 = Chain drives

Fig. 5.4 : Schematics of Winnower

Construction :Schematic arrangement is as described in Fig. 5.4. A fanis arranged with axis horizontal. Fan speed is 150 rpm uniform. Total

DR

DS

DRDS

HuskCH1

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speed rise from small sprocket to fan is 5.68. Two stage rise is obtained

each having 43/18 rise.

Operation : Mixture of grains & husk is arranged to drop vertically. Airblast created by fan removes husk. About 600 kgf of grains/hr areprocessed. Operating cost is Rs. 100/day.

The machine occupies 1.5 m x 0.5 m space. It does not need afoundation. Small flywheel is required.

5.6 Smith's Hammer

There are two versions of this machine, A) Drop Forge Type and B) CamType [54].

S= Seat , P= Pedals, H= Hammer, 04A= Crank, AB=Connecting Rod, PLT=Platform,

F=Flywheel, SP1,SP2,SP3,SP4 = Chain Sprockets, CH1,CH2,CH3 = Chain Drives,

X are bearing locations.

B

O4O3

O1

S

PLT

H

P

SP4

CH3

SP3

SP1 CH1SP2

CH2F

O3

O1

O2

Figure 5.5 : Schematics of Drop Forge Hammer

A

O

P

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A) Drop Forge Type

Construction: In this machine a rectangular shaped hammer 38 x 35 x35 cm3 is arranged as a slider of a slider crank chain. Crank radius is 7.0cm & connecting rod length/crank length = 8.0 thereby achieving fairly

S.H.M. for hammer.Transmission comprises of a speed rise by chain drive with speed ratio =44/19 = 2.33 and torque amplification 4:1 by a gear drive. Flywheel isprovided for avoiding cyclic speed fluctuations.

Operation: Job is placed at the dead center position of the hammer. Fig.

5.5 Describes Schematic Arrangement.

B) Cam Type

Construction :Fig. 5.6 Describes schematic arrangement of the machine.RRD Cam is provided giving instantaneous drop giving hammering action.

Transmission comprises of speed rise provided by a chain drive of the

order of 56/46 = 1.21 where as torque amplification is provided of theorder of 44/18 = 2.44. Flywheel is provided to avoid cyclic speed

fluctuations.

Figure 5.6 : Schematics of Drop Forge Hammer(Cam Type)

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5.7 Wood Strips Cutter

Constructions : A serrated blade having uniform rectilinear motion is

arranged [54]. Total speed rise is 7.56. This comprises of four stages :

First Stage 1.08 (52/42 = 1.08), Second stage 124/49, Third Stage 49/32(Second and third stage by gears), Fourth Stage again by chain drive45/25 = 1.08.

Operation: Band saw speed 350 m/m on a job of 125 mm2& 50 cuttingoperations are performed in a shift giving production capacity as 4.5

sq.m./8 hours. This yields Rs. 200/day earnings for the operator.

CSB

Teeth 52

P

S

S0

CH1

Teeth 48

S1

Teeth 49

Teeth 124

S2

Teeth 49

Teeth 32

S3

FW

G

G

Direction

of Feed

Teeth 45

P1

P2

Teeth 24

CH2

S4

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S = SeatP = Peddles

CSB = Cutting Seareted BladeP1 = Blade Pulley (Driving) 56 cm dia

P2 = Blade Pulley (Driven) 56 cmCH1 = Chain Drive

FW = Fly WheelCH2 = Chain Drive 2

Photograph of Drop Forge Hammer

Photograph of Wood Strip Cutter

Figure 5.7: Schematics of Wood Strips Cutter

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5.8 A Wood Turning Process

The research [50] described here reports on comparison of operationalcharacteristics of two systems to energise wood turning process. Thesesystems are (1) Using Human Powered Flywheel Motor and (2) on loadfeeding.

5.8.1 Experimentation

Flywheel Motor as Energy Source (Test A)

In this test rider energises the flywheel for 1 minute during which the woodturning operation is not performed. After this, peddling is stopped andimmediately wood turning is commenced which continues till whole kineticenergy of the system is exhausted. Time of operation of the lathe isrecorded.

Fig .5.8 : Experimental Response to wood Turning

On Load Test (Test B)

In this test as the rider starts peddling, wood turning is simultaneouslycommenced. The rider pedals only for 1 minute but the wood turningcontinues till the kinetic energy of the system is exhausted.

During both these tests, for every observation XT plotter plots rpm of mainshaft FS versus time and drum recorder plots float travel versus time. Fromthese plots, the plots of energy stored in the flywheel versus time and ofenergy input by the rider versus time averaged for all the riders are deduced.These have been presented in Fig. 5.8 for tests A and B.

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5.8.2 Analysis of Results

Overall Averaged Performance of Test A

Total energy input per cycle of operation of 135 seconds is 14500 N-m, outof which 4200 N-m is left in the flywheel before commencing wood turningprocess. The difference 10300 N-m energy can be attributed towards (1)error in estimation of energy input from exhaled air (2) energy required foraccelerated activities of body physiological functions and (3) energy requiredto over come windage and friction losses. It is rather difficult to apportionthis 10300 N-m energy in to its above stated components. The efficiency ofthis test is 28.96%.

Overall Averaged Performance of Test B

Total input energy per cycle of 135 seconds is 21000 N-m. Out of this 3500N-m is left in the flywheel after peddling is stopped. 3500 N-m energy isavailable for the remaining part of wood processing which continues foralmost the same period of 75 seconds as in Test A after peddling. Hence, itmay be predicted that in this phase material removed may be 16.85 cubiccms. Hence during peddling the material removed may be about 34.15 cubic

cm which might need 7090 N-m energy. Hence, the energy needed toovercome losses during peddling is 10410 N-m this test as against 10300 N-m in test A. In fact as this is onload test this loss should have been muchgreater. But the fact that it is not so, may be because the wood turningprocess may not be appreciably loading the system. Effectively, 10590 N-mof 21000 N-m input energy is utilised in this test for woodturning giving50.42% efficiency.

Salient Operational Characteristics

Fig. 5.8 indicates that input energy rate is higher for test B than for test A.This infers that higher the load higher is the human energy input. There isno significant rise and difference in the terminal speed attained by flywheelafter 40 seconds in both the tests. This infers that (1) riders maximumfrequency of thigh oscillations decides the terminal speed and (2) it isindependent of load.

5.8.3 Conclusion

Cycle time of both the tests is 135 seconds. With the present system, test Bis more efficient than test A by 74% where as B is more taxing than A by

50% from the human energy input point of view. If mechanical system isfabricated and assembled with greater accuracy, the overall system efficiencyis likely to be increased considerably. Experimental verification of this maybe considered as suggested further work. For any test, peddling time shouldbe 40 seconds only.

5.9 Electricity Generation

Here idea is to provide self sustained rural electrification for a house of 4family members. Each person of the house will operate HPFM for 1.5 hours

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per day [56]. A process machine is a D.C. generator of 2.5 KW self excitedtype. Torque needed by the generator is proportional to the armaturecurrent. In the duration of 8 hours/day enough electricity is stored in thebattery so that 6 bulbs of 60 watts capacity can be fed with electric power for5 hours during late evening and early night.

A diode rectifier is necessary to prevent battery discharge during a slow

speed operation of a generator on account of a possibility of reverse powerflow. New concept of equivalent mechanical resistance of charging process isevolved through this work.

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REFERENCES

[1] J. P. Modak," Manufacture of Lime-Flyash-Sand Bricks using Manually DrivenBrick Making Machine". Project Report :- Project sponsored by MHADA,Bombay-1982.

[2] A. Agrawal, et all, "Improved Design of Manually Driven Brick MakingMachine". Proceedings of International Conference on Modelling & Simulation,CAIRO, (EGYPT) 1987, AMSE PRESS, FRANCE, VOL.3-A, March-1987, pp 73-87.

[3] J. P. MODAK, "General Considerations of the Mechanical Design of ManuallyDriven Process Machine". Proceedings, 3rd NACOMM 87, IndustrialApplications, Group H, 1987, pp13-20.

[4] J. P. Modak & Mrs. S. D. Moghe, "Design & Development of a HumanPowered Machine for the Manufacture of Line-flyash-sand Bricks" HumanPower Vol. 13, pp 3-8, 1998, Journal of International Human Powered VehicleAssociation, U.S.A.

[5] J. P. Modak, "Bicycle Drive Mechanism & it's Adoption to the Development ofa Manually Energised Process Machine" Invited Lecture, National Seminar onHuman Engineering, Jan.'95 Organised by VIT, Pune & IIIE Chapter, Pune.

[6] J. P. Modak & A. R. Bapat "Design of Experimentation for EstablishingGeneralised Experimental Model for a Manually Driven Flywheel Motor".Proceedings of International Conference, Modelling & Simulation, New Delhi,Oct. 1987 vol. 8, pp 127-140.

[7] J. P. Modak & A. R. Bapat. "Design of Experimental Set up forEstablishing Generalised Experimental Model for Manually Driven FlywheelMotor "Modelling, Simulation & Control, B, AMSE, Press. France vol-26, 1989,pp 2329.

[8] J. P. Modak & A. R. Bapat "Experimental Setup for a Manually Driven FlywheelMotor" Industrial Engineering Journal (India), March 1989, pp 8-12.

[9] J. P. Modak & A. R. Bapat "Methodology of Minimizing Extraneous Variables

of a Manually Driven Flywheel Motor & Approach for Mathematical Analysis ofResults". Modelling, Simulation & Control. B. AMSE PRESS, FRANCE, VOL-29,no. 3, 1990, pp 55-64

[10] J. P. Modak & A. R. Bapat, "Formulation of Generalised Experimental Modelfor a Manually Driven Flywheel Motor and its Optimization", AppliedErgonomics, U.K., vol. 25, No. 2, 1994, pp 119-122.

[11] A. R. Bapat, "Experimental Optimization of a Manually Driven Flywheel Motor"M.E. (by Research) Thesis of Nagpur University 1989, under the supervisionof Dr. J. P. Modak.

[12] J. P. Modak & A. R. Bapat "Improvement in Experimental Setup forEstablishing Generalised Experimental Model for Manually Energised FlywheelMotor". Proceedings of National Seminar on Human Engineering, Jan. 95

Organised by IIIE & VIT, Pune. pp 109-126.[13] J. P. Modak & A.R. Bapat "Design of Experimentation to Establish Generalised

Experimental Model for Manually Energised Flywheel Motor for New Set ofResponses" Proceedings 2nd International Symposium on ErgonomicsOccupational, Health, Safety & Environment Conference (ISI-OH-SF) NewDelhi (India) Nov. 96. Abstracts S-5 (4)

[14] J. P. Modak & A. R. Bapat., " Various Efficiencies of a human poweredflywheel motor , Human Power, International Journal of Human PowerVehicle Association, U.S.A. No. 54, Spring 2003 pp. 21-23

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[15] A. R. Bapat, "Formulation of Generalised Experimental Models for variousDynamic Responses of a Manually Energised Flywheel Motor". Ph. D. Thesis ofNagpur University, 1996 under the supervision of Dr. J. P. Modak.

[16] J. P. Modak, "Bicycle-it's Kinematics and Modifications" Proceedings ofNational Conference on Machines & Mechanisms, Feb. 1984, pp 5-12.

[17] J. P. Modak & S. Ketkar "Design of Experimentation for Comparison of VariousBicycle Drive Mechanisms". Modelling, Simulation & Control, C, AMSE Press,France, vol. 9, No. 1, 1987, pp 33-46

[18] K. V. Chandurkar, et all "Experimental Verification of Various Bicycle DriveMechanisms Part-i". Proceedings of International AMSE Conf., Modelling &Simulation Control, KARLSRUHE (WEST Germany), vol 3-A, July 1987, pp139-160.

[19] J. P. Modak & Mrs. S. D. Moghe, "Comparison of Some Bicycle DriveMechanisms Designed in the Light of Transmission Angle Optimization & J.Papadopolos Hypothesis-Part I" Proceedings of International conference onMechanical Transmission & Mechanisms (MTM'97) (IFToMM) Organised byUniversity of Tianjian, China, July '97. pp 1087-1091.

[20] J. P. Modak & Swati Moghe, "Comparison of some Bicycle DriveMechanisms Designed in the Light of Transmission Angle Optimization & J.

Papadopolos Hypothesis Part-II ", Proceedings International Symposium onMachines & Mechanisms (IFToMM) University of Belgrade 1998 pp.

[21] Mrs. S. D. Moghe, et all "Design of Experimental Setup for OptimisingCranking Arrangement for Cycle Rickshaw". Proceedings of 2nd InternationalSymposium on Ergonomics, Occupational Health, Safety & Environment. (ISI-OHSF) New Delhi (India) Nov. 96. Abstracts S-5 (1).

[22] S. D. Moghe & J. P. Modak "Formulation of Generalised Experimental Modelfor Determination of Optimum Cranking Arrangement of a Cycle Rickshaw"10th IFToMM World Congress Uni of Oulu, Finland, June 20-24, 99 Acceptedfor presentation.

[23] Murell K. F.H., Ergonomics, Man in His Working Environment, Chapman andHall Ltd., London, 1965.

[24] William A. Williams, Mechanical Power Transmission, Manual, Book Division,Conovex-Mast Publications, Inc., 1953, p 358.

[25] A. Tyagrajan, et all "Development of on Load Starting Positive Clutch forFrequent on-off' Proceedings of 3rd IFToMM Speciality Symposium on RotorDynamics, Vibration Control, France. Sept. 1990. Accepted for Presentation.

[26] J. P. Modak & S. K. Gupta, "Concept and Dynamics of On-Load StartingPositive Finger Type Torsionally Flexible Clutch with Frequent On-Off'Accepted for Presentation at International Conference on MechanicalTransmissions and Mechanisms. (MTM'97) University of Tiajin, China, July '97.

[27] J. P. Modak & J. T. Pattiwar, "Concepts and Functional Viability of on LoadStarting Positive Clutches with Frequent on-off." Accepted for Presentation at

International Conference on Mechanical Transmissions and Mechanisms. (MTM'97) University of Tiajin, China, July '97.

[28] J. P. Modak, et all, "Design Proposals of New Type of clutches Essential forProcess Machines with Manually Energised Flywheel Motor as an EnergySource." Proceedings of International Conference on Mechanical Transmissionand Mechanisms. (MTM'97) University of Tiajin, China, July'97 pp 1078-1082.

[29] R. Deshmukh & J. P. Modak," Necessity, Development and Further Scope ofTorsionally Flexible Clutch-an update". 10th IFToMM World CongressUniversity of Oulu, Finland, June 20-24, 1999 accepted for presentation.

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[30] R. Deshmukh, et all, "Formulation of Generalised Experimental Model for theDynamics of finger Type Torsionally Flexible Clutch". Proceedings, CCM'98Clude-Bernard Uni of Layon, France, July 98. pp-16.31 to 16.34.

[31] R. Deshmukh et all "Dynamics of a Flywheel Shaft & Load Shaft of aMechanical System Incorporating Torsionally Flexible Finger Type ClutchAdopting a State Variable Approach". VIBRO ENGINEERING 98, Uni ofKaunas, Lithunia, Sept. 24-26,98. Session Paper G.

[32] J. T. Pattiwar et all "Formulation of Approximate Generalised Experimental

Model of Various Types of .Torsionally Flexible Clutches" Proceedings, CCM'98,Clude Bernard University of Layon, France, July 98, Paper 16.10 pp - 16.35 to16.38.

[33] V. V. Sohoni, et all "Mechanical Design of Transmission of a ManuallyEnergised Process Machine." Proceedings International Conference onMachine and Mechanisms (IFToMM). University of Belgrade, 1998 June.

[34] J. P. Modak, Mrs. R.V. Uddanwadikar Dynamic and Vibration Response ofFingers in a Finger Type Torsionally Flexible Clutch Journal of VibrationInstitute of India ( International Journal) Dec 2004, sent for publication.

[35] J. T. Pattiwar, "Design, Development and Analysis of Torsionally FlexibleClutches for on load Starting of a Manually Energised Machine". M.E. (by

Research) thesis under the supervision of Dr. J. P. Modak, Nagpur University(INDIA), 1997.

[36] R. Deshmukh, "Dynamics of a Torsionally Flexible Clutches" M.E. (byResearch) Thesis under the supervision of Dr. J. P. Modak, Nagpur University(INDIA), 1998.

[37] J.T, Pattiwar, Advancement in the Development of Finger Type TorsionallyFlexible Clutch For A Low Capacity Manually Energised Chemical UnitOperation Device a thesis submitted for award of Degree of Doctor ofPhilosophy to Nagpur University, 2004, under the supervision of Dr. J.P.Modak

[38] R. D. Askhedkar & J. P. Modak, "Modelling of Manually Driven Brick MakingMachine to Simulate Design Data Experimentally" Modelling, Simulation &

Control, B, AMSE, Press, France. vo1.4, 1985, pp 29-64.

[39] R. D. Askhedkar & J. P. Modak, "Calibration of Tachometer-A Case Study"Proceedings of 28th Congress of ISTAM. Dec. 1983, paper ET-5, DEC. 1983.

[40] R. D. Askhedkar et all "An Overview of Methodology of Experimentation"Proceedings of 28th Congress of ISTAM Dec-1983. paper ET-6, Dec. 1983.

[41] R. D. Askhedkar & J. P. Modak, "Hypothesis for the Extrusion of Lime Flyash-Sand Bricks using Manually Driven Brick Making Machine". Building Research& Information U.K., vo1.22, No.l, pp 47-54, 1994.

[42] R. D. Askhedkar & J. P. Modak, "Techno-Economic Feasibility of ManufactureLime-Flyash-Sand B