pdr final project

8/9/2019 PDR Final Project

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B.TECH (M & AE) VIII SEMESTER[BTM 860] PROJECT -

PRELIMINARY DESIGN REPORT

____________________________________________________

SAENIS EFFI CYCLE 2013 HYBRID TRICYCLE

“AEROJET A-01

”

____________________________________________________

Authors:

Debraj Roy, Dhaval Jain, Kulkeerty Singh,

Amit Kumar A. Singh, Deepak Kumar, Harshit Agarwal

B.Tech (M & AE) VIII Semester

Amity School of Engineering & Technology, Jaipur

Under the guidance of

Mr. Mangal Singh Sisodiya

(Department of Mechanical Engineering)

Amity School of Engineering & Technology, Jaipur

Report Due Date:

10 March 2014


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Design Overview

The vehicle involves a recumbent design for front driver & accommodates regular seating

position for rear rider. Owing to changes in rules & increase in the overall vehicle length to

maximum of 100in. led to ease of accommodating both drivers one behind the other. The

recumbent seating for front rider increases comfort while he/she focuses on steering the vehicle.The provision of side impact members increases overall collision safety of riders without hindering

mounting stances of entry & egress. Any instances of front or side impact has been neutralised by

use of the impact members. The front double wishbone suspension with A-arms & rear pivot-type

suspension provide a smooth & comfortable road experience to the riders especially keeping in

mind the potholes & deteriorated roads in many towns & villages throughout the globe. Disc brakes

for all individual tyres provide efficient braking with optimised braking distances & speeds. Use

of derailleurs & gears in transmission helps overcoming even the most difficult & steepest terrains

with ease & negligible chances of slip.

Trike Specifications

Direct steering with customized horizontal grips not only reduces confusion & skill level

requirement of rider & significantly improves road feel, enabling high G-force turnings. An

aesthetic fabrication provides an appealing look to the tricycle. The trike can be simultaneously be

driven by the combined power by both human & electric drive

1. Trike frame

With looks of a Rolls Royce Phantom incarnated in a tricycle, the design meets requirements

of safety, ergonomics & connects them to innovation. All the vital systems- steering, suspension,transmission, braking have been made of best possible configurations as needed for enhanced

comfort.

Member Outer Diameter Wall Thickness

Top tube 37.5mm 1.25mm

Down tube 37.5mm 1.25mm


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Seat tube 37.5mm 1.25mm

Seat stays 25.4mm 1.00mm

Chain stays 25.4mm 1.00mm

Bottom bracket 54.3mm 2.00mm

2. Material

Material selection was done with emphasis on strength & weight. As for the core, AISI 4130

was been selected owing to its high weldability, easy machinability. As it has Chromium &

Molybdenum as strengthening agents so it can be hardened by heat treatment.

Pros

Principal Design Features: AISI 4130 is a low carbon steel containing molybdenum and

chromium as strengthening agents. The carbon content is nominally 0.30%. The alloy can be hardened by heat treatment.

Machinability: Machinability is best with the alloy in the normalized and tempered

condition. Although the alloy may be machined in the fully heat treated condition,

machinability becomes more difficult with increasing strength (hardness) of the alloy.

Welding: 4130 alloy is noted for its weldability by all of the commercial methods.

Aging: Not applicable to this alloy.

Easily available across India.

Physical Property Value Chemical

Composition

Elemental Wt %

AISI 4130 AISI 316 AISI 4130 AISI 316

Density x103kg/m3 7.7-8.03 8 C 0.28-0.33 0.08

Elastic Modulus (GPa) 190-210 170-200 Mn 0.40-0.60 2.0

Tensile Strength (Mpa) 620 515 P 0.035 (max) 0.045

Yield Strength (MPa) 434.3 205-290 S 0.04 (max) 0.03

Elongation(%) 28.2 40-50 Si 0.15-0.30 1

Reduction in area(%) 55.6 50 Cr 0.80-1.10 16-18

Hardness (HB) 156 79 Mo 0.15-0.25 2-3

Ni 10-14

3. Wheel Base & Track Width

To achieve high speed stability longest possible wheelbase of 1460mm has been selected for

the vehicle with maximum length of 2470mm so that a clearance of 70mm (3in) from the limit of


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2540mm (100in) was achieved. This contributed greatly in limiting vehicle track width to an

astounding 850mm & obtaining a streamlined design for improving aerodynamics of vehicle.

Minimal wind resistance would be faced by riders even on rough windy or cloudy days as the

vehicle spears through wind, thus giving it its name “Aero Jet A-01”.

4.

Weight DistributionWith a 45/55 weight distribution i.e. 45% weight on the front & rest on the rear end, easy

cornering with reduced rear tire wear is achieved. Since the vehicle is rear drive & electric drive

also powers up rear wheel, no reduction in performance is seen. The weight of the vehicle is 42kg.

5. Tires & Rims

Position Rim Diameter Tyre Thickness Tyre Diameter

Front 20” 1.75” 23.5”

Rear 24” 2.125” 28.25”

Selection of tires was been done by keeping in mind the need of superior traction while driving

& the bearing of load of 2 people of around 130kg each. Two small tires at front improve steering

response without hindering the clearance rule of 8” for any component so that suspension

components could be accommodated.

6. Braking System

Mechanical shoe brakes with independent control for both front & rear tires have been included

in the design. A double barrel brake lever helps actuating both front shoes simultaneously.

Reduced chances of skidding & smoother braking are achieved, whilst calculations show much

optimized braking distance.

Parameter Specifications

System Mechanical Shoe Brake System

Actuation Conventional handle & cable


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Pads High performance metal ceramic compound

Weight 96 grams/wheel (Excludes adapter & mounting bolts)

Braking Distance

Condition: Vehicle must stop within 5m when it covers 50m in 15 s i.e. speed=3.33m/s

=

+ = .

for Velocity, v = 3.33m/s; Acceleration due to gravity, g = 9.81m/s2; Coefficient of friction, f =

0.6; Roadway grade as %, G = 0.02

s = 3.95m

for Velocity, v = 6.94m/s (average speed); Coefficient of friction, f = 0.6

Retardation

=

= . / for

Velocity, v = 6.94m/s (average speed); Stopping distance, s = 5.88 m/s

Braking force

= = . for

Mass = vehicle mass + 2 persons of 115 kgs = 270kg

Braking Time

= −

= . for

Velocity, u = 6.94 m/s; Final velocity, v = 0m/s; Retardation, a = - 6.09m/s2

Stopping energy

= .

= .

for

Kinetic energy, KE = 0.5mu2 = 6502.08 J; Potential energy, PE = 0 J (as slope = 0);

Rotational energy, Rot. E = 3% KE = 195.06 J

Brake power

= = .

Brake ratio & efficiency

=

=

.


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= ( %) = %

7. Suspension System

Double Wishbone with A-arms at front & a pivot-type rear suspension at rear protects rider

from the bumpy roads & adds to comfort of riders. While double wishbone reduces brake dive,

increases steering response & limits sway, the mono shock between top & seat tube of rear rider

is easy to be implemented & sufficient enough to combat the 30% of shock that the vehicle

experiences altogether. For dampers of spring rate 46.58N/mm a maximum deflection on the

dampers come out to be 11.43mm.

8. Steering System

A highly responsive Direct Steering with the kingpins on both hubs having a connecting

rod to sync with each other is been set up for the front rider. Horizontal grips give traditional &

improved road feel. Additional gear changer is being mounted alongside the handle bars. The low

cost, simplicity & low weight makes the system very efficient.

Pros:

Simple and inexpensive implementation, uses single tie-rod system.

Gives rider good and safe feel as the direct steering is responsive and offer good road feel.

Direct steering is responsive and gives you a good road feel.

Less complicated system as compare to indirect steering system, easy for maintenance.

Low cost and less weight then other.

Max inner wheel angle (θi): 30˚

Max outer wheel angle (θo): 24.9˚

Effective turning radius: 3.27m

Where, Wheel base, b = 1460mm

Track, a = 850mm

Ackermann’s Angle

tan = ℎ ℎ

2 ∗ ℎ

1

= 1

&

=


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Caster Angle 12°

Camber Angle -2°

Kingpin Inclination 8°

Toe 0°

Turning Radius(R) Value

Inner front wheel (R i) 2.93m

Outer front wheel (R o) 3.27m

9. Transmission System

While human power on the crank wheels for both riders adds up at the rear derailleur to

power the rear wheel through freewheels, a PMDC motor with speed reduction jackshaft on

insulated rear carrier forms the electric drive. Idler gears are used for transferring power from front

rider.

Pros:

Better traction during hill-climbing due to rear wheel drive

Light weight, Economical, Low power consumption.

An average adult can put out about 100 watts on a continuous basis & about 200 to 300 Wcontinuously for an hour working up a sweat while about 500W in a 30s burst. A bicycle racer can

put out 600 W continuously for an hour. Our bicycle with a 0.5HP W motor will go about the

speed of a human-power only bicycle pedalled hard by a healthy adult (20.2 km/h). The motor rpm

on a DC motor is directly related to voltage & so increasing the voltage from 24 to 36 V (50%)

will increase no-load shaft speed by 50%. As the motor produces more heat, so continuous current

and therefore power should not be expected to increase by 50%.


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Motor Specifications Battery Specifications

Type PMDC Quantity 3

Voltage Range 24-36V Type Lead Acid

Rechargable

Wattage 0.5HP Resistance 9.3mΩ

Torque 12kg-cm Operating Current 0.5HP

Current 13.6A Torque 24Ah@2hr-rate

Weight 9kg Voltage per Unit 12V

RPM/V 80 Max. Discharge Current 30A

Weight 7kg

RPM/V 80

Killswitch is attached to the +ve terminal of battery & the wire extends to the charger &

motor controller which completely puts all electrical connections to sleep upon killswitch

triggering. Mobile charging can be introduced and can be switched from pedal power to battery

mode by the help of the switch as shown above in the fig.

For front driver

A series of idle wheels are used to route the chain from front axle to the rear wheel. The chain is

almost twice the conventional cycle chains.

Pros:

High performance & reliability, Use of light-weight bearings, Low cost, lesser no. of

Universal joints.


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Cons:

Adding of unwanted dynamic weight of drive train, less traction.

o Front Chain Ring (Sprocket): 44T - 7” Φ

o Crank size : 165mm

Average human height in India is 166cm for male and 155cm for female. Average

human leg is 80cm.

Thus crank size 160mm +5mm(extra)=165mm

Pros: 44T chain ring is easily available in market at low cost and to

obtain greater gear ratio for high speed. Lowering or raising of gear ratio isn’t possible as

Rear chain ring is bolted to Front chain ring of 2nd driver.

Low gear ratio will need 2nd driver to increase his paddling speed (cadence) and it

would be difficult for him.

Higher gear ratio will cause the front driver to increase his paddling speed (cadence). Thus gear ratio 44/44=1 is selected.

Leg (cm) 50 52.5 55 57.5 60 62.5 65 67.5 70 72.5 75 77.5 80 82.5 85 87.5 90 92.5

Child(mm) 110 115 120 125 130 140 145 150 155 160 160 165 170 175 175 180 180 185

Adult(mm) 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185

For rear driver

Rear chain ring of 1st driver and Front chain ring of 2nd driver bolted to each other areused. Freewheels (21T) with index type shift is used to transmit power from rear driver to rear

wheel.

Pros:

Smoother, quieter, faster shifting:

Sprocket design allows the chain to engage two adjacent sprockets simultaneously.

The sprocket meshes before it disengages from the old one.

Differently shaped individual teeth on the same sprocket & ramps formed into the

sides of the sprockets facilitate downshifting.

While in conventional derailleur systems, shift occurs by the chain moving sidewaysuntil it can no longer mesh with the sprocket it is on.

o Chain Pitch: 1.27 cm or 0.5”

o Chain length

Front driver sprocket - rear driver sprocket: 360cm

Rear driver sprocket - rear wheel sprocket: 137cm


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Since, Chain length = 2*c + (F/4) + (R/4) + 1

c= distance between two chain ring;

F= front chain ring teeth

R= rear chain ring teeth

o Number of links

Front driver sprocket to rear driver sprocket: 142

Rear driver sprocket to rear wheel sprocket: 54

Max speed: 50 km/h

Max weight of riders: 2 x 115 = 230kg

o Front drive sprocket

Diameter: 17.78cm

Teeth: 44cm

o Velocity ratio

=

=

= .

Load: 850 kg

Service Factor (K s): 1.562

Assumed permissible speed of smaller sprocket (N1): 3300rpm

Speed of Larger Sprocket (N2): 1352.46 rpm

Avg. chain velocity = ∗∗

= .∗∗.

= . /

Breaking Strength:

= ∗ = ∗ . = .

Factor of Safety:

=

=

.

= .

Power Transmitted:

= ∗ ∗

= . ∗ .

.∗. = . = .

Front/Rear Gain Ratio Speed @100rpm Speed @120rpm

Mph Kmph Mph Kmph


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Bottom bracket-Bottom of Seat 460mm

Bottom bracket height (Front) 250mm

Handle bar – Top of Seat (Front) 350mm

Handle bar - Bottom of Seat (Front) 320mmCrank Length 175mm

Seat height 340mm

Finite Element Analysis on ANSYS Workbench 14.0 (Non-Commercial)


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Production Plan Layout


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Pictorial Presentation of Work Progress

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