oscar hällfors - divakth.diva-portal.org/smash/get/diva2:1113251/fulltext01.pdf · 2017. 6....

Conceptual Design of a Cable

Attachment Device for a Mining Machine

Oscar Hällfors

Master of Science Thesis MMK 2017:89 MKN 198

KTH Industrial Engineering and Management

Machine Design

SE-100 44 STOCKHOLM

I

Examensarbete MMK 2017:89 MKN 198

Konceptuell Konstruktion för en Kabelupphängningsanordning för en

Gruvmaskin

Oscar Hällfors

Godkänt

2017-06-09

Examinator

Ulf Sellgren

Handledare

Ulf Sellgren

Uppdragsgivare

Svea Teknik AB

Kontaktperson

Jacob Wollberg

Sammanfattning

Den här rapporten är resultatet av ett examensarbete utfört på mastern för maskinkonstruktion på

KTH i samarbete med Svea Teknik AB och Atlas Copco Rock Drills AB.

Atlas Copcos avdelning för bergbrytning håller på att utveckla en ny maskin som ska användas

för malmbrytning. Maskinen är tänkt att den ska kunna användas utan att ha några operatörer på

eller kring maskinen medan den arbetar. Maskinen och dennes system skall därför kunna styras

från en annan plats eller autonomt.

För att maskinen ska kunna arbeta utan operatörer på plats krävs en anordning som kan hantera

och hänga upp de kablar och slangar som krävs på gruvväggen allt eftersom maskinen bryter

malmen. Målet med detta examensarbete har varit att konstruera ett koncept för denna

anordning.

Projektet innehöll flera faser så som bakgrundstudie, konceptgenerering, konceptevaluering,

konceptutveckling och dokumentation.

Under konceptgenereringsfasen togs åtta koncept på olika hängare för kablarna fram varav en

valdes ut att användas. Därefter togs fem olika koncept på anordningar fram och efter en kort

utvärdering av koncepten valdes en vidareutveckla till ett fungerande koncept.

Konceptet verifierades sedan utifrån de krav som ställts i kravspecifikationen.

Det slutgiltiga konceptet är baserat på ett länkarmsystem som sätter fast hängaren och kablarna

på samma gång i nätet.

Nyckelord: kabelupphängning, bergbrytning, kabelhängare

III

Master of Science Thesis MMK 2017:89 MKN 198

Conceptual Design of a Cable Attachment Device for a Mining Machine

Oscar Hällfors

Approved

2017-06-09

Examiner

Ulf Sellgren

Supervisor

Ulf Sellgren

Commissioner

Svea Teknik AB

Contact person

Jacob Wollberg

Abstract

This report is the result of a master thesis project from the master in machine design at KTH in

cooperation with Svea Teknik AB and Atlas Copco Rock Drills AB.

Atlas Copco’s department for rock drills and excavation is currently developing a new machine

for underground mining. The machine is supposed to work without any operators on it or around

it while it excavates. The machine and its systems should therefore be able to be controlled

remotely or autonomously.

To operate the machine without any operators nearby the machine demands a device that could

handle and attach the cables and hoses necessary for the machine to operate on the mine wall as

it operates and excavates. The purpose of this master thesis has therefore been to design such a

device.

The project included many stages such as a background study, concept generation, concept

evaluation, concept development and documentation.

During the concept generation phase eight concepts of hangers to attach the cables and hoses to

the wire mesh was generated. One of these hangers was then chosen to use later with the device.

With the hanger chosen five concepts for the device was generated and after a short evaluation of

the concepts one was chosen to develop further.

The concept was verified with the requirement specification in consideration.

The final concept is based on a link arm system that attaches the hanger and cables at the same

time on to the wire mesh.

Keywords: Cable hanger, mining

V

FOREWORD

I would like to thank my supervisors at KTH and Svea Teknik for the support and time during

the past months that they have given me. I would also like to thank Atlas Copco for the project

and opportunity to work with them. A lot of thanks to my fellow colleagues during this master’s

thesis whom I would not have suffered all this time without. Together we have been through a

lot of laughter, many fights and a lot of frustration but I will look back and remember our time

here together with a smile.

Oscar Hällfors

Stockholm, 2017-05-31

VII

NOMENCLATURE

In this chapter the notations and abbreviations that are used in the report presented and

explained.

Notations

Symbol Description

Fmax Highest force allowed on the wire mesh (N)

rmesh Radius of the wire in the wire mesh (m)

Fyield Yield force of the wire in the wire mesh (N)

Vhose Volume of the water hose (m3)

rhose Radius of the water hose (m)

lhose Length of the water hose (m)

mhose Mass of the water hose per meter (kg/m)

ρwater Density of water (kg/m3)

msignal Mass per meter of the signal cable (kg/m)

Asignal Area of the signal cable (m2)

Apower Area of the power cable (m2)

mpower Mass of the power cable per meter (kg/m)

AA Area in port A (m2)

AB Area in port B (m2)

AA,1 Area 1 in port A (m2)

AA,2 Area 2 in port A (m2)

AB,1 Area 1 in port B (m2)

AB,2 Area 2 in port B (m2)

Fcyl Cylinder force (N)

p Hydraulic pressure (Pa)

Tvane Torgue from the rotation vane actuator (Nm)

Avane Area of the vane in the vane actuator (m2)

rvane Radius from the axis to the middle of the vane (m)

rinner Inner radius of the cable when bent (m)

rcemter Center radius of the cable when bent (m)

router Outer radius of the cable when bent (m)

F1x Force in joint 1 in x-direction (N)

F1y Force in joint 1 in y-direction (N)


VIII










Fmcyl1 Force from gravity in cylinder 1 (N)

Fmcyl2 Force from gravity in cylinder 2 (N)

Fmlink1 Force from gravity in Link arm 1 (N)

Fmlink2 Force from gravity in Link arm 2 (N)

Fload Force from the load acting on the Link arm (N)

lcyl1 Length of cylinder 1 (m)

lcyl2 Length of cylinder 2 (m)

lmcyl1 Length to center of mass in cylinder 1 (m)

lmcyl2 Length to center of mass in cylinder (m)

g Gravity (m/s2)

l1 Length of Link arm 1 (m)

l2 Length of Link arm 2 (m)

l3 Length to joint 4 (m)



h1 Height to joint 3, 4 and 6 (m)

h3 Height to joint 5 (m)

α Angle of Cylinder 2 (°)

β Angle of Link arm 2 (°)

γ Angle of Link arm 1 (°)

φ Angle of Cylinder 1 (°)

time Time used in ADAMS simulation (s)

Acyl Area of cylinder (m2)

psystem Hydraulic pressure in system (Pa)

rcyl Radius of the cylinder (m)

pvane Hydraulic pressure in vane actuator (Pa)

FMATLAB Force from MATLAB results (N)

FADAMS Force from ADAMS results (N)

IX

Abbreviations

CAD Computer Aided Design

RVM Remote Vein Miner

FEM Finite Element Method

Pro/E Pro Engineer

Tramming Moving the machine without excavating

Ore Mineral rich rock

Muck Crushed ore from the mine

XI

TABLE OF CONTENTS

1 INTRODUCTION .............................................................................................. 1

1.1 Background .................................................................................................. 1

1.2 Problem Description .................................................................................... 1

1.3 Purpose ........................................................................................................ 2

1.4 Delimitations ............................................................................................... 2

1.5 Method ......................................................................................................... 3

1.6 Requirements Specification ......................................................................... 4

2 FRAME OF REFERENCE ................................................................................ 5

2.1 The Machine ................................................................................................ 5

2.2 Wire Mesh ................................................................................................... 6

2.3 Cables and hose ........................................................................................... 7

2.4 Hangers ........................................................................................................ 9

2.5 Hydraulic cylinders.................................................................................... 10

2.6 Rotational vane actuator ............................................................................ 11

3 CONCEPT PHASE .......................................................................................... 13

3.1 Concept Generation ................................................................................... 13

3.2 Hanger Design Concepts ........................................................................... 14

3.3 Hanger Evaluation ..................................................................................... 18

3.4 Device Concepts ........................................................................................ 20

3.5 Concept Evaluation.................................................................................... 23

3.6 Detailed Concept ....................................................................................... 23

4 RESULTS AND VERIFICATION .................................................................. 31

4.1 Load on the Link Arm ............................................................................... 31

4.2 Allowed Bending Radius ........................................................................... 32

4.3 Reach of the Link Arm .............................................................................. 33

4.4 Forces in the Joints in the Link Arm ......................................................... 35

4.5 Dimensioning of the Cylinders .................................................................. 41

4.6 FEM Analysis ............................................................................................ 42

4.7 Worst Case ................................................................................................. 46

4.8 Weight of the Device ................................................................................. 46

XII

4.9 Hydraulic rotational actuators ................................................................... 47

4.10 Requirements Fulfillment .......................................................................... 48

5 DISCUSSION AND CONCLUSION .............................................................. 49

5.1 Discussion .................................................................................................. 49

5.2 Conclusion ................................................................................................. 50

6 RECOMMENDATIONS AND FUTURE WORK .......................................... 51

7 REFERENCES ................................................................................................. 53

APPENDIX A: Power Cable Product Sheet ........................................................... 55

APPENDIX B: Equation System ............................................................................ 57

APPENDIX C: MATLAB FORCE CALCULATIONS ......................................... 59

APPENDIX D: MATLAB PLOT ........................................................................... 61

APPENDIX E: FEM Convergence Test ................................................................. 65

APPENDIX F: Fatigue Analysis ............................................................................. 67

APPENDIX G: Worst Case FEM Analysis ............................................................ 69

1

1 INTRODUCTION

This chapter includes background information, problem description, purpose, delimitations and

choice of method to be used during this project.

1.1 Background

Atlas Copco Rock Drills AB manufactures machines for mining and excavation both over- and

underground. In underground mining it is common that the machines run on electricity due to

difficulties with air ventilation deep in the mines. If a combustion engine where to be used in

these machines the tunnels would become filled with exhausts and make it a non-suitable

environment for people to work in. The machines are usually powered by a power cable attached

at the end of machine on a cable reel and lets out the cable while it moves forward. The cable is

then attached to the mine wall on a steel wire mesh, which prevents rocks from falling, with

hangers to make sure that it is not in the way for other machines and to protect it from getting

damaged from sharp rocks on the ground. The process to put the power cables on the walls is

mainly done manually by an operator.

Atlas is currently working on a new machine called the Remote Vein Miner, RVM. On the new

machine the voltage is going to be higher than earlier machines and therefore the cable cannot be

handled by hand. The cable must be handled with an insulated stick which makes the task

tedious and a bit more complicated. Also, during operation of the machine a lot of dust stirs up in

the mine creating a rough environment to work in for the operators. It is therefore desired to

make this process automated or remotely operated.

Svea Teknik AB took on this task as a master thesis project with KTH. Svea Teknik has a history

of working together with Atlas Copco with similar machines and master thesis projects.

1.2 Problem Description

The power cable and other necessary cables and hoses are today put up on the wall by an

operator by hand. With a higher voltage this cannot be done by hand and instead an insulated

stick must be used. This process is desired to make autonomous or remotely operated so that the

manual work could be eliminated.

The task is to design a device that can attach and detach a power cable, other cables and hoses

that are required for the machine to operate, on to the mine wall while excavating. The device

should be able to attach the cable while the machine is moving forward and detach it when

moving backwards.

2

The mine walls are stabilized with a steel wire mesh that prevents the wall from collapsing. This

wire mesh could preferably be used to attach the cables/hoses since it will also be attached by the

machine as it excavates further into the ground. Figure 1 shows a typical mine tunnel with cables

on the ground and on the wall.

Figure 1 Cables on the ground and wall in a mine (Provided by Customer)

1.3 Purpose

The purpose of the project is to generate a conceptual design of a cable attachment device that

can attach the cables and hoses on the mine wall with a hanger when the machine operates. The

device should be able to work remotely controlled and/or autonomously while the machine is

moving forward and backwards. If the concept is good enough it could later be further developed

and implemented on the machine and by so reduce the manual and potential dangerous work for

operators working with the machine and around it.

1.4 Delimitations

The project has a limited time frame of 20 weeks and therefore the following delimitations have

been set:

Wire mesh assumed to already be mounted on the wall

General solid mechanic calculations/simulations

No specific parts selection or suppliers

Bearings will not be dimensioned or implemented in the design

Other sub systems of the machine are disregarded

Design interface of the CAD locked at 25th

January

Since the machine that this project faces towards is under development the interfaces and

parameters will change during the time frame of the project and therefore this project will regard

the machine and its design as it were the 25th

of January.

Cables

3

1.5 Method

A stage gate method was chosen for this project. In Figure 2 all the planned stages and gates are

shown in a chronological order. At each gate all stages before it must be approved before moving

on to the next stage.

Figure 2 Stage Gate method chart

To generate the stages in the stage gate method the seven step design process described by N.

Cross (Cross, 2000) was taken as inspiration for the concept generation and evaluation stages.

Figure 3 Seven step design process (Cross, 2000, p. 58)

Thesis

Application

Svea Teknik

Meeting with

Atlas Copco

Choice of

Project

Gate

1

Start at

Svea Teknik

Plan ProjectBackground

Research

Gate

2Requirements

Gate

3

Concept

Generation

Concept

Evaluation

Detailed

Concept

Gate

4Evaluate

Document and

Write ReportPresentation

Gate

6

Gate

5

Start at Svea Teknik

Planning SeminarConfirm Requirements

Choose Concept

Hand in Preliminary

Report

Hand in Revised

Report

• Brainstorming

• Morphological chart

• Evaluation matrix

• Feasibility Analyze

• Verification

• Improvements

Overall

Problem

Sub-solutionsSub-problems

Overall

Solution

Clarifying

objectives

Establishing

functions

Setting

requirements

Generating

alternatives

Evaluating

alternatives

Improving

details

Determining

characteristics

4

The concept generation stage was divided into two separate stages. The first stage was to design

and evaluate a concept for the hanger that holds the cables on the wall that was going to be used

and the second stage was to design a device that with this hanger would fulfill the task to attach

the cables and the hoses to the mine wall. To generate the concepts a method using

brainstorming and a morphological chart were used.

The evaluation of the concepts was made using an evaluation chart where one concept was

chosen as a datum reference that the other concepts were compared to through a couple of

criteria’s. If the concept was better than the datum on a criteria it was given a “+”, if it was worse

than the datum it was given a “–“ and if they scored the same as the datum it was given a “0”.

The score was then summarized and the concept with the highest score was the best concept

according to the evaluation chart. The result of the evaluation chart was taken into consideration

when choosing the concepts to develop further.

The final concept was designed using the CAD software Pro/ENGINEER (PTC) and the

verifications of the concept was done using MATLAB (MathWorks), ADAMS (MSC) and

ANSYS Workbench (ANSYS).

A status report were uploaded to the school supervisor once a week with the progress of the

project and with an update of the time plan.

1.6 Requirements Specification

Following requirements were discussed with the customer and were wished to be fulfilled.

Table 1 Requirements specification

Description Quantity

Ort dimension, maximum H = 4980 mm W = 5130 mm

Ort dimension, minimum H = 4500 mm W = 3200 mm

Machine size H = 3600 mm W = 2000 mm

L = 22000 mm

Size of device Should fit behind the machine

Weight of device No max, ~500 kg

Number of cables/hoses

1 cable 4.5kg/m ø53 mm

1 water hose ø 38 mm (1.5”)

1 signal cable ø 15 mm

Distance between hangers max 3 m

Speed (tramming) max 500 m/h

Operating speed (machine) 1.5 m/h

Distance between reconnecting 150 m

Wire mesh dimensions Wire ø3 mm, 50 x 50 mm

Environment 35°C, high moist

Attach/Detach Should be able to attach/detach

cable and hangers if possible

Time frame 20 weeks

Life span About 6 years

Quality Robust

Cable Bending Radius 8 ⋅ O.D. (Overall Diameter)

5

2 FRAME OF REFERENCE

Following knowledge about the project has been gathered before the design process was started.

2.1 The Machine

The RVM is a continuous mining machine that cuts rocks with a vertical rotating wheel in the

front of the machine. The cutter wheel has a number of small cutters that are pressed against the

mine wall with such a high pressure that small chips of rock loosen and falls to the ground (the

muck). The machine then transports the muck with a conveyor belt under the machine to its back

where it is collected and transported away from the mine. The RVM works in cycles and the

cables are reconnected every 150 m. The machine is supposed to have an automatic bolting

device that also puts up the wire mesh on the wall. This device is placed in the middle of the

machine before the cable attachment device.

Figure 4 Remote Vein Miner (Provided by Customer)

The dimensions in Figure 5 displays approximate dimensions of the machine that needs to be

taken regards to during the design of the concept. To the left is a view from the side of the

machine and the right directly from behind.

Figure 5 Approximate dimensions of the interface

1300

1300

100

26002400

1600

2000

800

850

590

1200

6

2.2 Wire Mesh

The wire mesh that is going to be used on the mine wall is of the type Chain Link Mesh or

“Gunnebostängsel” as it is called in Sweden. Figure 6 displays a simple sketch of the wire mesh

appearance.

Figure 6 Sketch of a Chain Link Mesh (“Gunnebostängsel”)

The wire mesh has the dimensions described in Figure 7.

Figure 7 Dimensions of the wire mesh

The space between the wire mesh and the mine wall is limited. The wire mesh is pressed against

the mine wall with bolts which leaves a small to no gap between the wire mesh and the wall at

some places.

50 50

Ø3

7

A typical wire mesh of this kind has a yield strength of 450-500 N/mm2 according to a supplier

(Perimeter Protection, 2017). Figure 8 displays a simple free body diagram of the wire mesh.

Figure 8 Simple free body diagram of the wire mesh

Fmax = 2 ⋅ Fyield ⋅ cos(45°) (1)

With Fyield = π ⋅ rmesh2 ⋅ 450 N/mm2 ≈ 3180 N. Then Fmax become about 4450 N which roughly means that the highest load that can be hung in one point on the wire mesh is about 450 kg. The situation is however more complex than that due to that the wire mesh is knitted and sliding will occur in the wire mesh.

2.3 Cables and hose

As specified in the requirement specification, Table 1, there are two cables and one water hose

that are needed for the machine to operate. Their dimensions are presented in Figure 9 next to a

sketch of the wire mesh, the sizes are scaled relative to each other.

Figure 9 Cables and hose relative size to the wire mesh

Fmax

Fyield Fyield

Ø 53

50 Ø 38Ø 15

Power Cable

Water Hose

Signal Cable

Wire Mesh

8

The weight of the water hose per meter was estimated with following equations

Vhose = π ⋅ rhose2 ⋅ lhose

(2)

and

mhose = ρwater ⋅ Vhose. (3)

Where rhose = 19 mm, ρwater = 998 kg/m3 (Björk, 2011, p. 70) and lhose=1 m. Equation (2) and

Equation (3) gives that the mass per meter is about 1 kg/m. To simplify the estimation the shell

of the hose was assumed to be water. The water was assumed to have a higher density than the

shell so the hose itself could weigh less but not more than the estimation.

Properties for the power cable are found in APPENDIX A. The product id for the cable is 1/0

AWG.

The weight of the signal cable was approximated by assuming that it had the same density as the

power cable. The quotient of the area between the signal cable and power cable then gives the

weight of the signal cable, Equation (4).

msignal = Asignal/Apower ⋅ mpower (4)

By using Equation (4) the signal cables weight was estimated to 0.37 kg/m.

9

2.4 Hangers

The hangers used in the mining industry today have a lot of different appearances and functions.

Figure 10 and Figure 11 are just two examples.

Figure 10 displays a sketch of a hanger from SSORRICH who develops equipment for the

mining industry. With the two hooks the hanger can hold multiple cables and separate those if

that is wanted.

Figure 10 Sketch of a trailing cable hook from SSORRICH (SSORRICH, 2017)

The S-hook from CAB PRODUCTS is a simple hanger made to easily hang up cables and other

equipment on fences or nets.

Figure 11 Sketch of an S-hook from CAB PRODUCTS (CAB PRODUCTS, 2017)

10

2.5 Hydraulic cylinders

Double acting cylinders work in both directions depending on which port that is pressurized

(Rabie, 2009, p. 258) . The force of the cylinder is given by the area of the piston and the

pressure. The area AB becomes smaller due to that the rod takes some of the area and therefore

the force to retract the piston will be smaller if the same pressure is used in both ports.

Figure 12 Principle sketch of a hydraulic double acting cylinder

Double acting telescopic cylinders works like the double acting cylinders but have more

sections, see Figure 13. Telescopic cylinders are good when there is limited space and a long

stroke length is required (Rabie, 2009, p. 260).

Figure 13 Principle sketch of a hydraulic double acting telescopic cylinder

A

B

AA

AB

A

B

AA,1AA,2

AB,1AB,1

11

2.6 Rotational vane actuator

A hydraulic rotational vane actuator works by adding a hydraulic pressure in port A or B, Figure

14. The hydraulic pressure acts on the vane rotor in the actuator pushing it around the axis and

generating a rotational motion. The vane rotor is connected to an output shaft. Due to the design

of the actuator the range is limited to about 320 degrees (Rabie, 2009, p. 265).

Figure 14 Principle sketch of hydraulic vane actuator

The torque generated in the actuator is given by the area of the vane and the pressure and can be

calculated with Equation (5).

Tvane = Avane⋅ p⋅ rvane (5)

Where Avane is the area of the vane, p the pressure in the system and rvane the distance from the

shaft to the middle point in the vane.

A good precision of the rotation can be achieved with the right controller of the hydraulic flow.

A B

13

3 CONCEPT PHASE

This chapter presents the concept generation, evaluation and final concept.

3.1 Concept Generation

To generate the concepts a method using brainstorming and a morphological chart (Cross, 2000,

pp. 124-138) have been used. The morphological chart is a good tool to generate many

alternatives and concepts. However, some of these concepts do not work or are too complex so

they must be evaluated too see how reasonable and feasible they truly are.

Table 2 Morphological chart

Solution

Function 1 2 3 4 5 6

Cable

holder Hook Clip String Cable tie Glue Carabiner

Attach to

wire mesh Hook "Pine tree" Glue Bolt plate

Snap

fastener

Expand

rubber

cylinder

Detect

distance

from wall

Push

sensor

Optical

sensor

Stereo

sensor Camera

Feedback

from

machine

Release

from device

Air

pressure

Pushing

rod

Pull off

with force

from link

arm

Wire

tension

Z- and Y-

direction Two links

Three

links

Z- and Y-

directional

pistons

X-direction Mounted

on slider

Rotational

actuator

X-

directional

piston

Actuate

motion of

link arms

Gears Hydraulics Pneumatics Electric Spring

loaded

Magazine Revolver Vertical Horizontal Spiral

Attach to

the machine

Shelf

behind

Shelf on

top

One sided

shelf on

top

Hinged

arm on

the sides

14

For this project the morphological chart was not sufficient. The morphological chart has been

good for brainstorming alternative solutions but was hard to use to deliver a final overall

solution. Therefore the morphological chart, Table 2, was divided into two stages where the first

stage generated hanger concepts and the second stage generated concepts for the device. The

morphological chart could be divided into two separate matrixes in relation to the two stages

described. These matrixes would be divided as follows:

Rows 1-2, attaching the hangers and cables to the wire mesh

Rows 3-10, device to attach the hanger

3.2 Hanger Design Concepts

The first task in the concept generation was to decide which kind of method that was going to be

used to attach the cables to the wire mesh. The attachment to the wire mesh is a key feature in

the design and therefore it was needed to be decided first. Following concepts for the attachment

was generated as options. The concepts were modelled in Solid Edge ST5 (Siemens).

3.2.1 Concept 1 – Hook

Using a conventional S-hook like hanger to attach to the wire mesh and hold the cables. The

hanger will be pressed against the wire mesh and be pulled downwards. The hanger will then be

released from the device when a specific load is applied to ensure that the hanger has attached

correctly to the wire mesh. The device will then lay down the cables on to the hanger in the

hook.

Figure 15 S-hook concept

15

3.2.2 Concept 2 – Flanges

This concept attaches to the wire mesh with flanges that folds out when they are pressed against

a surface, the mine wall. The flanges could be designed with barbs on the end to make sure that

they hook on to the wire mesh firmly. As Figure 16 shows the attachment method requires the

hanger to be mounted with a high precision to be inserted into a hole in the mesh. Therefore it

should be designed so it can attach even if it is pressed against the wire mesh as well.

Figure 16 Flanges concept

3.2.3 Concept 3 – Cable tie

The idea with cable ties is to simplify the cable laying process. With the cable tie the cables can

be attached directly with the tie on to the wire mesh. The cable ties are for single use and can be

cut when collecting the cables.

Figure 17 Cable tie concept

16

3.2.4 Concept 4 – Pine tree

The hanger attaches to the wire mesh by pushing it into one of the holes in the wire mesh. The

wire in the wire mesh sticks into the space between the flanges and makes sure that it does not

fall of. The hanger could be collected again by pulling it out from the wire mesh. When the

hanger is loaded with cables the pulling force is downwards and the hanger should stay in place.

Figure 18 Pine tree concept

3.2.5 Concept 5 – Clip

In this concept the hanger is attached to the wire mesh with a clip. The clip makes it possible to

easy detach it and reuse it. The process of attaching it might though become a bit more

complicated.

Figure 19 Clips concept

17

3.2.6 Concept 6 – Staples

This concept is inspired by a staple. A thin and flexible metal bar that is bent to place over the

cables and into the wire mesh when pressed against the rock wall on the other side of the wire

mesh.

Figure 20 Staple concept

3.2.7 Concept 7 – Bolting plate

The wire mesh on the wall is hold in place by bolts with a plate on it. The plate has a loop in

which could be used to attach a small hook in. Since the bolt and plate is fixed on to the wall it

makes a good and secure fastening point.

Figure 21 Bolting plate concept

18

3.2.8 Concept 8 – Hook and loop

The idea of this concept is to use a hook and loop type band that could be wrapped over the

cables and on to the wire mesh. To attach the cables to the wall the device will hold the cables

and the hose to the wall and roll over with a roller that pushes the hook and loops through the

wire mesh and makes it stick to it.

Figure 22 Hook and loop concept

3.3 Hanger Evaluation

The hangers were evaluated with an evaluation chart (Cross, 2000, p. 161). A non-weighted

evaluation was chosen due to its simplicity. Concept 1 was chosen as datum reference.

Table 3 Evaluation chart for the hanger concepts

Hanger Concept

1 2 3 4 5 6 7 8

FU

NC

TIO

N

Attachability

- + - - - + +

Collectable

- - 0 0 - 0 0

Reusable D - - 0 0 - 0 -

Compact storing A - + - 0 + 0 +

Manufacturing T - + - - + 0 -

Cost U - + - - + 0 +

Hold the cables M 0 - 0 0 - 0 -

Weight

0 + + 0 + 0 +

Complexity of

attachment device + - + - 0 - -

∑ - 0 6 4 4 4 4 1 4

∑ + 0 1 5 2 0 4 1 4

Total 0 -5 1 -2 -4 0 0 0

19

According to the evaluation only one concept scored better than the datum. With the evaluation

in consideration and a discussion with the customer Concept 1 was chosen as the best method for

the attachment.

Due to new demands during the evaluation of the hanger concepts the chosen hanger needed

some modifications. The new demand was that the cables needed to hang separate from each

other. The new design was based on SSORRICH hanger, Figure 10, and the modification can be

seen in Figure 23.

Figure 23 Three hooked hanger

20

3.4 Device Concepts

After the attachment method was chosen following concepts for the device was generated with

the morphological chart in mind. Figure 25 to Figure 29 shows drawings of the generated

concepts. On the left side of the figure there is a view from above the machine and on the right

side of the figure there is a view from behind the machine. Figure 24 shows how the

morphological chart was used to generate a concept, in this case concept 3

Figure 24 Morphological chart concept generation

3.4.1 Device concept 1 – Horizontal rolling applicator

Figure 25 shows the first concept. In this concept the wheel rolls on the wall as the machine is

moving forward and mechanically attaches the hangers. The cables are guided in a chute that

follows around the wheel and at the end lays the cables and the hose down into the hangers

separate hooks.

Figure 25 Device concept 1

21

3.4.2 Device concept 2 – Hydraulic cylinders

Figure 26 shows the second concept. In this concept the hanger is attached to the wall with

hydraulic arms. The hydraulic arms collect a hanger and then pushes the hanger so the hooks

goes in between the cables and the hose and transports them to the wall all at once. A small

modification for the hanger is needed for this concept.


3.4.3 Device concept 3 – Link arm

Figure 27 shows the third concept. The principle of this concept is much like concept 2 but

instead of hydraulic arms there are two link arms that sets the motion. The link arm pushes the

cables and the hose in between the hanger feeder and the head of the link arm. The link arm then

picks up the hanger with the cables and the hose and transports them to the wall and attaches

them. The cables and the hose are here secured from falling of the hanger on the way to the wall.


22

3.4.4 Device concept 4 – Vertical rolling applicator

Figure 28 shows the fourth concept. In this concept the device attaches the hangers to the wall

with a horizontal wheel. The cables and the hose are guided over the device in chutes and then

laid down into the hanger.


3.4.5 Device concept 5 – Side mounted hanger applicator with cables on top

Figure 29 shows the fifth concept. A side mounted hanger feeder attaches the hangers to the

wall. The cables and the hose are guided by tubes into the hanger on the wall.


23

3.5 Concept Evaluation

An evaluation chart has been used to evaluate which of the concepts that seems to be the best

alternative to develop further.

Table 4 Evaluation chart for the device concepts

Concept

1 2 3 4 5

FU

NC

TIO

N

Size

+ + + +

Weight

0 + 0 +

Robustness D + + 0 -

Complexity A 0 - 0 +

Reach T + + 0 -

Flexibility U + + - -

Reliability M + + - 0

Speed of hanger

dispenser 0 0 0 0

∑ - 0 0 1 2 3

∑ + 0 5 6 1 3

Total 0 5 5 -1 0

Concept 2 and 3 scored the same in the evaluation, both with much better scores than the other

concepts. At the end, concept 3 was chosen to be developed further. Concept 3 was chosen over

concept 2 because it had better flexibility and reach when compared to each other.

3.6 Detailed Concept

Developing the concept was an iterative process and an overview of the final design can be seen

in Figure 30.

Figure 30 Overview of the detailed concept

Link arm device

Conveyor belt

Shelf

Hanger feeder

24

The link arm has two hydraulic cylinders that actuates the motion towards the mine wall.

Hydraulic cylinders were chosen since the machine already have a hydraulic system

implemented in it. The lower hydraulic cylinder was chosen as a telescopic cylinder to increase

the stroke length so that the wanted reach of the arm could be achieved. The link arm stands on a

rotational actuator to increase the reach of the arm, and also because this is needed to fulfill the

requirement of the bending radius or the cable.

Figure 31 Link arm design

A bearing arrangement is needed for the link arm and the base to rotate easily. As seen in Figure

32 a thrust ball bearing could work for this application. The bearing in Figure 32 is just an

example and has not been dimensioned or verified. The rotational motion is then provided

directly by a rotational actuator. The type of actuator has not been chosen or dimensioned. A

rotational single vane actuator is sufficient to reach out from both sides of the machine but if the

link arm should be able to rotate 360 degrees another option must be considered like a hydraulic

motor or electric stepper motor.

Figure 32 Cut view pf the rotational actuator in the base

Telescopic hydraulic

cylinder

(Cylinder 1)

Hydraulic cylinder

(Cylinder 2)

Hydraulic

rotary vane

actuators

Rotary actuator

Wall push sensor

Hanger release sensor

Link arm 1

Link arm 2

Head

Hanger

Base

25

The angle of the head is controlled by two hydraulic rotational vane actuators. These actuators

are connected to a hinge between link arm 2 and the head. Figure 33 shows the actuators and

their rotation.

Figure 33 Rotation of the head

The head lifts up the hanger with pins that goes under the hooks in the hanger, left picture in

Figure 34. This method was chosen to reduce the complexity of the device. Another retractable

spring loaded pin makes sure that the hanger stay in place during the transport from the machine

to the mine wall. The retractable pin folds in when the hanger is loaded into the head and when

the hanger is loaded on to the head and ready to be transported the pin gets pushed out again to

make sure that the hanger does not fall off on the way to the wall. The pretension in the springs

then determine the force needed to pull off the hangers from the head on to the wall. This

mechanism could with a sensor work as an insurance that the hanger has attached to the wall.

Figure 34 Cut view of the head

Pins

Spring

loaded pin

Spring loaded pin

Actuator with

sensor

Rounded pin

Spring

26

For the device to work, some kind of sensor must be added to detect the distance to the wall. In

this concept a push sensor on top of the head was chosen due to its simplicity. When the head

closes in to the wall, the wheel on the push sensor touches the wall and the push sensor then

detects the distance. When the head is close enough to attach the hanger it moves downwards

and attaches the hanger with the hook to the wire mesh. The wheel on the push sensor protects

the sensor from getting damaged when the head is moving downwards.

Figure 35 Push sensor

The hanger feeder has a magazine that can fit 50 hangers (one for every 3 meters). The feeder

elevates one hanger at the time so that the link arm can collect the hanger with ease. Three

grooves has been implemented into the feeder to steer the head into position when collecting the

hanger. A cover over the hangers protects them from getting dust into the hanger feeder system.

Figure 36 Hanger feeder and magazine

Hanger magazine, 50 hangers

Hanger feeder

Grooves

27

The cable feeder arranges the cables and the hose so the head can collect them at the same time

as the hanger. The cable feeder is also needed to collect the cables and hose since the cable reels

in the machine is not strong enough. The cables are fed through the cable feeder with rollers.

There are three pairs of rollers, Figure 37. In each pair the bottom roller is motorized and the top

one is adjustable in height so different cables can be used and also the right clamping force

needed for the feeder to work can be set.

Figure 37 Cable feeder

To attach the hanger and cables and hose to the wire mesh the link arm first gets into position in

front of the hanger feeder. Then it pushes the heads arms in between the cables and collects a

hanger. Figure 38 shows the link arm in position to collect the hanger and the cables and the

hose.

Figure 38 Position to get the hanger

Motors

Handles to

adjust roller

height

28

The link arm lifts the head out of the hanger feeder with the cables and the hose. It then follows

the cables and the hose to the wall. During the transport the cables and the hose are secured from

falling off by the geometry of the head and the hanger, Figure 39.

Figure 39 Head moving towards the wall

Figure 40 shows the head attaching the hanger with the cables and the hose to the wire mesh. The

hanger hooks on to the wire mesh and the link arm moves the head downwards, releases the

hanger and lays the cables and the hose down into the hooks in the hanger.

Figure 40 Hanger attached to the wall

29

Figure 41 shows how the result of the cables and the hose hanging on the wall could look if the

concept is working as planned. The cables and the hose hangs separately from each other on the

hooks in the hangers. The slack between the hangers can be controlled by the cable feeder. Since

each cable has a separate motor in the cable feeder the slack of each cable or hose can be set

individually.

Figure 41 Hangers successfully attached to the wire mesh with the cables and the hose

31

4 RESULTS AND VERIFICATION

In this chapter the concept generation is verified that it works as intended.

4.1 Load on the Link Arm

The load on the link arm has been calculated with the properties in Table 5.

Table 5 Cable properties

Item Quantity Unit

Power cable weight 4.5 kg/m

Signal cable weight 0.37 kg/m

Water hose weight 1.14 kg/m

Distance to wall from

cable feeder 2.1 m

Cable length on wall 3.3 m

Total length 5.4 m

Total weight of cables ~33 kg

The cable length on the wall is 3.3 meters but half of that weight is supported by the previous

hanger. For the calculations the whole length has been considered due to that when the hanger is

attached it will be lifted slightly higher than the previously attached hanger and therefore the

whole weight might lay on the head and the link arm.

The total weight from the cables was rounded up to 33 kg. The weight from the hanger, the head,

the hinge and the motors also needs to be added. The weights are presented in Table 6.

Table 6 Weight

Item Quantity Unit

Cables 33 kg

Head 20 kg

Hinge 3.6 kg

Hanger 0.5 kg

Motors ~2 kg

Total 59.1 kg

The acting load on the link arm is about 59.1 kg which gives Fload = 579.8 N.

32

4.2 Allowed Bending Radius

The bending radius of the power cable was verified with the sketches in Figure 42. The sketches

were drawn with the radius 450 mm. This radius was chosen since the minimum bending radius

according to the product sheet, APPENDIX A, is 8 ⋅ O.D. which is r = 424 mm. If the cables

centerline is bent with this radius the smallest radius becomes slightly smaller due to the

thickness of the cable. Therefore half the diameter of the cable was added to this radius and

rounded to 450 mm.

Figure 42 Bending radius

Here in Figure 43 the phenomena of the bending of the inner, outer and the middle bending

radius is visualized.

Figure 43 Inner and outer bending radius

rr

rrr

r

r

rr r

r

rinner

router

rcenter

ØD

33

4.3 Reach of the Link Arm

The reach of the link arm in this chapter is the theoretical reach of the link arm out to the large

and small ort profile from the machine and not the practical reach. Figure 44 and Figure 45

shows the reach of the arm on the two mine dimensions when the link arm is positioned

orthogonally out from the side of the machine. The two positions in both figures are the highest

and lowest the arm can reach with the head and hanger orthogonally against the wall in the two

different cases.

Figure 44 Small ort profile reach straight from the machine

Figure 45 Large ort profile reach straight from the machine

560

2515

1605

87

1366

2565

34

Figure 46 and Figure 47 shows the maximum reach behind the machine with the head and

hanger orthogonally to the mine wall. In these two figures the link arm is locked by the geometry

and cannot stretch out any further.

Figure 46 Small ort profile maximum reach

Figure 47 Large ort profile maximum reach

As stated the reach in this chapter is the theoretical and does not work in practice. In Figure 44

and Figure 45 the bending radius is exceeded and in Figure 46 and Figure 47 the link arm cannot

move up and down which is required. The practical area of reach is slightly smaller than the area

given in this chapter.

2080

502

947

502

35

4.4 Forces in the Joints in the Link Arm

The forces in the link arm has been derived from an ADAMS simulation. The ADAMS model

was verified with an analytical solution made with MATLAB in one specific case. The case

chosen was when Cylinder 1 fully compressed and Cylinder 2 is fully extended. This case was

chosen as it was deemed as the case where the forces in the joints would be the highest. Figure

48 displays the link arm positioned in the chosen case.

Figure 48 Figure of the position of the chosen case

To make the analytical solution a free body diagram over the chosen case was needed to

calculate the forces and equations. Figure 49 shows the free body diagram of Figure 48.

Figure 49 Free body diagram

F1x

F1y

F1y

F1xF2x

F2y

F2x

F2y

Fmcyl1

F3y

F3yF3x

F3x

Fmlink1

F4x

F4x

F4y

F4y

F5y

F5y

F5x

F5x

F6x

F6x

F6y

F6y

Fmcyl2

Fload

l1

Fmlink2

l3

lmlink1

l4

l2

l5

lmlink2

lcyl1

lmcyl2

lcyl2

lmcyl1

h1

h1

h1

h3

l4

γ

φ

α

β

Y

X

36

Following equations where derived from the free body diagram in Figure 49:

F2x – F3x = Fmcyl1 (6)

F1y – F2y = 0 (7)

F2y ⋅ lcyl1 ⋅ sin(φ) = Fmcyl1 ⋅ lmcyl1 ⋅ cos(φ) (8)

– F1y + F3y + F4y – F5y = Fmlink1 (9)

– F1x + F3x + F4x – F4y = 0 (10)

F3x ⋅ (l4 ⋅ cos(γ) – h1 ⋅ sin(γ))+ F3y ⋅ (l4 ⋅ sin (γ) + h1 ⋅ cos(γ))+ F4x ⋅ (l3 ⋅ cos(γ) – h1 ⋅ sin(γ)) + F4y ⋅ (l3 ⋅ sin(γ) + h1 ⋅ sin(γ)) – F5x ⋅ (l1 ⋅ cos(γ) – h3 ⋅ sin(γ)) – F5y ⋅ (l1 ⋅ sin(γ)

– h3 ⋅ sin(γ)) = Fmlink1 ⋅ lmlink1 ⋅ sin(γ)

(11)

– F4y + F6y = Fmcyl2 (12)

– F4x + F6x = 0 (13)

– F6x ⋅ lcyl2 ⋅ sin(α) = Fmcyl2 ⋅ lmcyl2 ⋅ cos(α) (14)

F5y – F6y = Fmlink2 + Fload (15)

F5x – F6x = 0 (16)

F6x ⋅ (l5 ⋅ sin(β) + h1 ⋅ cos(β)) – F6y ⋅ (l5 ⋅ cos(β) – h1 ⋅ sin(β)) = Fmlink2 ⋅ lmlink2 ⋅ cos(β)

+ Fload ⋅ l2 ⋅ cos(β) (17)

Equations (6) to (17) were rewritten into an equation system and solved using MATLAB. The

equation system is shown in APPENDIX B and the MATLAB script used to solve it in

APPENDIX C.

37

The known forces, lengths and masses used to solve the equation system is presented in Table 7.

The angles α, β, γ and φ was taken from the CAD model in the chosen case.

Table 7 Parameters used to solve the equation system

Parameter Quantity Unit

g 9.81 m/s2

l1 1340 mm

l2 1260 mm

l3 1125 mm

l4 215 mm

l5 640 mm

lcyl1 240 mm

lcyl2 830 mm

lmcyl1 lcyl1/2 mm

lmcyl2 lcyl2/2 mm

lmlink1 l1/2 mm

lmlink2 l2/2 mm

h1 75 mm

h2 230 mm

h3 100 mm

Fload 579.8 N

Fmlink1 245.25 N

Fmlink2 166.77 N

Fmcyl1 58.86 N

Fmcyl2 117.72 N

α 12.3 °

β 14.35 °

γ 68.81 °

φ 82.23 °

Figure 50 shows the result of the ADAMS model at is starting position. The model was built

with the points in Table 8. Between each body a cylindrical joint has been added except between

the bodies in the cylinders that have a translational joint between them. All inertias for all bodies

in the model was removed to get a static analysis in each step of the simulation.

Figure 50 Starting position of the ADAMS model

Cyl_2_1Cyl_2_2

Link arm 2Link arm 1

Base

Y

X

38

The joints in the right column in Table 8 are numbered as the forces in Figure 49.

Table 8 Positions of the ADAMS model

Item X Y Joint/Other

Base 0 0 Origin

-260 0 Joint 2

0 230 Joint 1

Link arm 1 0 230 Joint 1

- 1249.37 714.44 End of link arm 1

- 624.68 472.22 Center of mass

- 1076.02 566.78 Joint 4

-227.57 237.8 Joint 3

-1285.52 621.2 Joint 5

Link arm 2 -1285.52 621.2 Joint 5

-2506.2 308.88 End of link arm 2

-1895.86 465.04 Center of mass

-1886.96 389.9 Joint 6

Cyl_1_1 -260.0 0.0 Joint 2

-243.79 118.9 Cyl_1_3

Cyl_1_2 -235.68 178.35 Cyl_1_3


-246.83 96.61 Cyl_1_1

Cyl_1_3 -227.57 237.8 Joint 3

-243.79 118.9 Cyl_1_1

Cyl_2_1 -1076.02 566.78 Joint 4

-1283.64 521.495 Center of mass

-1491.26 476.21 Cyl_2_2

Cyl_2_2 -1491.26 476.21 Cyl_2_1


-1886.96 389.9 Joint 6

Cyl_1_1 and Cyl_1_3 was modeled as weightless and Cyl_1_2 compensates for those parts with

the total weight in its mass center. With the mass center in Cyl_1_2 the weight of the cylinder

stays in the right place through the simulation. Cyl_2_1 and Cyl_2_2 has half the weight each in

their own center of mass. The center of mass in Cylinder 2 is therefore not in the middle of the

cylinder during the simulation as in the analytical solution but close enough for the calculations.

Following motions were added to the model in its starting position before the simulation.

Motion 1: Between Cyl_2_1 and Cyl_2_1 to retract Cylinder 2.

Motion 2: Between Cyl_1_1 and Cyl_1_2 to move the middle part of Cylinder 1.

Motion 3: Between Cyl_1_1 and Cyl_1_3 to expand Cylinder 1.

39

The displacement velocity of the translational motion 1, 2 and 3 were set according to Table 9.

Table 9 Translational motions

Motion 1 (360/10) ⋅ time



Where the number in the numerator is the stroke length and the number in the denominator is the

time step. Time is the time parameter in ADAMS and must be set to the same as the denominator

or the simulation will not be complete. The simulation was set to static analysis.

Figure 51 displays the end position after the simulation with time = 10 s.

Figure 51 End position of the ADAMS model

Cyl_1_1

Cyl_1_2

Cyl_1_3

40

The result of the ADAMS simulation is presented in Figure 52. The figure displays the absolute

value of the forces and the direction of the forces can be taken from the free body diagram,

Figure 49. To generate the graph the result was exported from ADAMS and imported to

MATLAB. The script used to generate the graph can be found in APPENDIX D.

The graph shows that the highest forces in the joints is at the starting position (time = 0).

Figure 52 Forces in the joints as function of the stroke length of cylinder 1

The results of both models in the starting position are shown in Table 10. The ADAMS model

was verified with the MATLAB model. The difference between the results from both

simulations are presented in the right column in Table 10. Since the results of both models were

so close to each other both models was accepted as reliable.

Table 10 Comparison between the MATLAB and ADAMS results

Force MATLAB [N] ADAMS [N] Difference [%]

F1x 1255 1254 0.08

F1y 8059 8061 -0.02

F2x 1255 1254 0.08

F2y 9228 9230 -0.02

F3x 1255 1254 0.08

F3y 9169 9171 -0.02

F4x 8437 8439 -0.02

F4y 1781 1782 -0.06

F5x 8437 8439 -0.02

F5y 2645 2646 -0.04

F6x 8437 8439 -0.02

F6y 1898 1900 -0.11

The right column in Table 10 was calculated with Equation (18).

Difference = (FMATLAB – FADAMS)/FMATLAB ⋅ 100 (18)

41

4.5 Dimensioning of the Cylinders

The forces in the two cylinders are given by F3x, F3y, F4x and F4y. The resulting force in each

cylinder was calculated with Equation (19) and presented Figure 53.

Fcyl = (Fx2 + Fy

2)(1/2)

(19)

Figure 53 Resulting forces in the cylinders

As Figure 53 displays, the highest forces in the cylinders are at the starting point of the

simulation and the resulting force in this point is presented in Table 11.

Table 11 Highest forces in the cylinders

Cylinder Force [N]

1 9315

2 12463

The cylinders can be roughly dimensioned with the forces presented in Table 11 and Equation

(20) and Equation (21). The pressure is assumed to be psystem = 100 bar which is reasonable for a

machine like this.

Acyl = Fcyl/psystem (20)

rcyl = (Acyl/π)(1/2)

(21)

The smallest radius needed in the cylinders to actuate the link arm at the highest forces is

presented in Table 12 with the stroke lengths for each cylinder as well.

Table 12 Cylinder properties

Cylinder rcyl [mm] Stroke, min [mm] Stroke, max [mm]

1 17.3 240 545

2 20 470 830

42

Since the forces in the cylinders does not change direction through the simulation only one

direction of the cylinder is used and therefore the concept could work with single acting

cylinders. This is though with the specified load and how the forces becomes in the cylinders

without the specified load has not been tested.

4.6 FEM Analysis

A FEM analysis was performed to check if the link arms where in a reasonable size. The FEM

analysis was made with ANSYS and only the link arms and hinges were tested with the forces

calculated in the highest force case, the load on the link arm and the head set to 579.8 N.

The profiles for the link arms used in the FEM analysis are presented in Figure 54. Link arm 2

has a slightly thinner profile than Link arm 1. This was set to make Link arm 1 stronger since it

takes on a higher force than Link arm 2 and also so that the forces from the weight of Link arm 2

was reduced.

Figure 54 Profiles of Link arm tubes

Link arm 1 was modeled with the properties described in Table 13. The surfaces between the

hinges and the beam were set as bonded.

Table 13 Forces and supports in Link arm 1

Force [N] Joint 1 Joint 3 Joint 4 Joint 5

X 1255 Cylindrical

support

8437 8437

Y 8059 1781 2645

The overall result of the FEM analysis is presented in Figure 55. The highest stress is situated

between the top hinge (joint 4) and Link arm 1.

Link arm 1 Link arm 2

68

8080

64

43

A convergence test was made to verify the ANSYS model. The mesh size was set to 10 mm on

the link arm surface and hinge surface where they are connected. The mesh size was then

decreased 1 mm every run to see the change of the result. The results did not converge and the

license did not allow further reduction of the size of the mesh due to its limits in calculations.

The result of the convergence test and pictures of the mesh can be found in APPENDIX E. The

mesh size set to 4 mm was deemed to be a good mean result so it was chosen for the analysis.

Figure 55 Result from Link arm 1 FEM analysis

The stresses in Link arm 1 is presented in Figure 56. The stress in the beam in the link arm is

lower than the highest stresses in the analysis.

Figure 56 Link arm 1 from the side

Link 1 – max

Link 1 - side

44

The highest stress in the first analysis is shown in Figure 57. The stress is situated in a corner of

the model and is about 140 MPa which could be considered a reasonable stress.

Figure 57 The top hinge from link arm 1

Another analysis was made for Link arm 2. The model was modeled as the first analysis but with

the forces in Table 14

Table 14 Forces and supports in Link arm 2

Force [N] Joint 5 Joint 6 Joint load

X 8437 Cylindrical

support

0

Y 2645 579.8

The overall result of Link arm 2 is presented in Figure 58. The highest stress here is also between

the hinge and the beam. The stress in the hinge is in the same size as in the first analysis but the

beam is much lower.

Figure 58 Result from Link arm 2 FEM analysis

Link 2 - max

45

The stresses in the beam in Link arm 2 is presented in Figure 59. The maximum stress is about

98 MPa.

Figure 59 Link arm 2 from the side

The stress in the hinge in Link arm 2 is slightly higher. The maximum stress is about 170 MPa

which is higher than the beam. This stress is though situated in a corner as well and could be

considered as a result of a sharp corner in the CAD model.

Figure 60 The hinge from link arm 2

The stresses in the link arms are in a reasonable size for this construction. All the stresses in the

analysis are smaller than the yield stress for normal construction steel (Björk, 2011, p. 50) and

the construction is therefore deemed as valid.

Link 2 - side

Link 2 hinge max

46

4.6.1 Fatigue

A fatigue analysis was done using the built in function in ANSYS Workbench and the results

from the FEM analysis. The result of the fatigue analysis can be seen in APPENDIX F. The link

arm system will not be subjected to fatigue during the life time of the machine according to the

analysis.

4.7 Worst Case

The case described in chapter 4.1 describes a normal case where each hanger is placed with 3 meters from each

other. A special case is when one or more hangers fails to attach to the wire mesh correctly. A short analysis of this

case was made in ANSYS with the load Fload = 776 N, one hanger has failed to attach correctly (3.3 meters extra

cables). The result from this analysis is presented in APPENDIX G. The stresses in this case are higher but under the

yield strength in most points. There is though one point where it gets higher, but this is in a corner and the stress

there is most likely not that high. The stress at that point is about 216 MPa.

4.8 Weight of the Device

The weight of the concept has been calculated with the built in function for mass analysis in

Pro/E.

The weight of the concept design is about 260 kg for the link arm and the hanger feeder with the

magazine with 50 hangers about 238 kg. This however is without regards to any material choices

and dimensioning. The model has been modeled in construction steel and many parts have been

made solid for simplification and therefore the weight of the device would probably be lower.

The total weight of the concept without the shelf and cables has been estimated to about 500 kg.

47

4.9 Hydraulic rotational actuators

To dimension the hydraulic rotational actuators positioned in the hinge between the link arm and

the head the torque from lifting the cables and the head needed to be estimated. This was done

with the parameters in Table 15. The torque was estimated by taking the distance from the motor

axis to an approximate mass center off each item.

Table 15 Properties for torque calculation

Item Mass [kg] Length [mm]

Cables 33 338

Lift head 20 175

Hinge 3.6 8

Hanger 0.5 338

The needed torque in the hydraulic rotational actuators was estimated to 15.2 Nm.

The dimension of the vane in the actuator is shown in Figure 61. The shaft has a diameter of 20

mm. The force from the vane is applied at the center of the vane which is 15 mm from the center

of the shaft. Therefore the torque from the vane actuator is given by Equation (22).

Figure 61 Inner dimensions of the rotational actuator

Tvane = p ⋅ Avane ⋅ 15 (22)

With the given size of the vane in the actuator the needed pressure to actuate the rotation with

the normal load case is about pvane = 34 bar.

30

10

15

Shaft

Vane

48

4.10 Requirements Fulfillment

With the final concept design and the verification done a last check to see if the requirement

specification was fulfilled was made. The result is presented in Table 16

Table 16 Fulfillment of the requirements specification

Description Quantity Requirement fulfilled

Yes/No

Ort dimension, maximum H = 4980 mm W = 4800 mm Yes

Ort dimension, minimum H = 4500 mm W = 3200 mm Yes

Machine size H = 3600 mm W = 2000 mm

L = 22000 mm Yes

Size of device Should fit behind the machine Yes

Weight of device No max, ~500 kg Yes

Number of cables/hoses

1 cable 4.5kg/m ø53 mm

1 water hose ø38 mm (1.5”)

1 signal cable ø15 mm

Yes

Distance between hangers max 3 m Yes

Speed (tramming) max 500 m/h Possible

Operating speed (machine) 1.5 m/h Possible

Distance between reconnecting 150 m Yes

Wire mesh dimensions Wire ø3 mm, 50 x 50 mm Yes

Environment 35°, high moist Possible

Attach/Detach

Should be able to

attach/detach cable and

hangers if possible

Possible

Time frame 20 weeks Yes

Life span About 6 years Possible

Quality Robust Possible

Cable Bending Radius 8 ⋅ O.D. (Overall Diameter) Yes

Most of the requirements have been fulfilled. There are a few that have not been verified and

therefore marked as possible because they are deemed as so.

49

5 DISCUSSION AND CONCLUSION

Following chapter includes discussion, conclusions and reflections over the project and the

results.

5.1 Discussion

The method chosen became slightly inadequate when it came to the concept generation. But with

a slightly modification and dividing the concept generation into two stages it turned out well.

The generated concept fulfills most of the requirements in the requirement specification. The

requirement to be able to detach the hanger and cables and collect it again however has not been

verified due to the time frame of the project. However, by doing the attachment sequence in

reverse is a possible solution but would probably need some more sensors to be able to work

perfectly. Another solution to this problem could be to leave the hangers on the wall and use the

head plus one hanger to guide the cables of the hangers and reel them in. The hangers would then

be collected later and refilled into the device again.

The idea of using a hanger that either could be left on the wall or cut open like cable ties seems

like good choices to avoid the difficulties with collecting the hangers again. This though needs to

further investigated to see if it actually is a good solution.

The FEM analysis was made with a quick set up in ANSYS and a brief convergence test was

executed. Since no convergence was found, the results should be considered as an indication of

the stress in the link arms.

No fatigue analysis was done for the worst case. But since the stresses are under or slightly

higher than the yield stress this can be allowed to happen a few times.

Late in the project it was realized that the load case described in chapter 4.1 could be modeled in

a slightly different way that leads to that the cable length will be longer which will increase the

load. However, since the forces have been calculated in the link arms most extended position this

can be seen as compensation for the slightly higher load. The case where the cables become

slightly longer is when the link arm places the hangers behind the machine and not like the

position in Figure 30 which the cable lengths were taken from. In such case the extra length was

estimated to 1 m which would result in about 6 kg extra weight on the load.

If the concept is further developed it could fulfill the requirement of being autonomous or

remotely controlled. If this is achieved it would reduce the amount of time operators needs to be

around the machine in the mine and make it a better working place for them.

A brief patent search was done and no conflicting patent was found. The patent search was done

with Google Patents (Google Patents) and following key words: Cable, trailing, hanger, hook,

device, autonomous, remote operated, mine, mining and machine.

The hanger has been considered just as a design concept and has not been dimensioned.

Dimensioning and verifying tests of the hanger functions should therefore be executed to prove

that it is functional in the intended way. The size of the hanger could also be reduced with some

further optimization.

50

5.2 Conclusion

The conceptual design developed in this master thesis has a good possibility to work according

to the verifications carried out in this report. Though, some further design and engineering is

required for it to fully work.

51

6 RECOMMENDATIONS AND FUTURE WORK

In this chapter, recommendations on more detailed solutions and/or future work in this field are

presented.

Investigate further the possibility to attach the cables to the wire mesh with a disposable

hanger like a cable tie.

Investigate the possibility to attach the hanger directly to the wire mesh when the wire mesh

is put up on the wall and focus on getting the cables down in that hanger.

Build a prototype to verify that the head and link arm can attach the hanger to the wall in the

desired way.

Dimensioning of bearings and other parts must be done.

A more extensive FEM analysis for the whole system.

A dynamic analysis of the forces in the system and dynamic FEM-analysis.

A more extensive fatigue analysis of the link arms and other parts that is not dimensioned.

Optimization of the whole system with regards to the weight can be done.

Hydraulic control system is needed for the device to work, either an autonomous or operator

controlled. For both controlling options some more sensors or visual aid is needed for it to

work.

.

53

7 REFERENCES

(n.d.). Retrieved 06 05, 2017, from Google Patents: https://patents.google.com/

ANSYS. (n.d.). Workbench 17.1.

Björk, K. (2011). Formler och tabeller för mekanisk konstruktion (6th ed.). Spånga: Karl Björks

Förlag HB.

CAB PRODUCTS. (2017). CAB PRODUCTS CAB S-HOOKS. Retrieved April 3, 2017, from

http://www.cabproducts.com/s-hooks/

Cross, N. (2000). In Engineering Design Methods (3rd ed.). Chichester: John Wiley & Sons Ltd.

MathWorks. (n.d.). MATLAB R15b.

MSC. (n.d.). ADAMS.

Perimeter Protection. (2017, 03 01). Perimeter Protection Industrial Fence. Retrieved from

http://www.perimeterprotection.net/SE/offering/HomeVilla/industrialfence/fence/Pages/f

orzinkad.aspx

Provided by Customer. (u.d.).

PTC. (n.d.). Pro/ENGINEER Wildfire 4.0.

Rabie, M. G. (2009). Fluid Power Engineering. New York: McGraw-Hill Professional

Publishing.

Siemens. (n.d.). SOLID EDGE ST5.

SSORRICH. (2017). SSORRICH TRAILING CABLE (TC) HANGER. Retrieved April 3, 2017,

from http://ssorrich.com/product/tc-hanger/

55

APPENDIX A: Power Cable Product Sheet

Product sheet provided by customer.

57

APPENDIX B: Equation System

59

APPENDIX C: MATLAB FORCE CALCULATIONS

close all, clear all, clc

l1 = 1340e-3;

l2 = 1260e-3;

l3 = 1125e-3;

l4 = 215e-3;

l5 = 640e-3;

l6 = 260e-3;

lmlink1 = l1/2;

lmlink2 = l2/2;

g = 9.81; %Gravity

mcyl1 = 6;

mcyl2 = 12;

mlink1 = 25; % mass of link arm 1

mlink2 = 17; % mass of link arm 2

mload = 59.1;

h1 = 75e-3;

h2 = 230e-3;

h3 = 100e-3;

lcyl1 = 240e-3; %[240 545]*1e-3 ;

lmcyl1 = lcyl1/2;

lcyl2 = 830e-3; %[470 830]*1e-3 ;

lmcyl2 = lcyl2/2; % Length to middle of cylinder

phi = 82.23; %[84.62 59.67];

gamma = 68.81; %[(0:1:360)]; %49.63 59.67 från caden,

alfa = 12.3;%[29.16 6.87];

beta = 14.35; %[35.86 4.82];

% test1=lcyl1(1)*sind(phi(1))+h1*sind(gamma);

Fmcyl1 = mcyl1*g;

Fmcyl2 = mcyl2*g;

Fmlink1 = mlink1*g;

Fmlink2 = mlink2*g;

Fload = mload*g;

60

%% NEW

% F1x F1y F2x F2y F3x F3y F4x F4y F5x F5y F6x F6y

A = [ 0 0 0 1 0 -1 0 0 0 0 0 0

0 0 1 0 -1 0 0 0 0 0 0 0

0 0 0 0 lcyl1*sind(phi) (-1)*lcyl1*cosd(phi) 0 0 0 0

0 0

0 -1 0 0 0 1 0 1 0 -1 0 0

-1 0 0 0 1 0 1 0 -1 0 0 0

0 0 0 0 (l4*cosd(gamma)-h1*sind(gamma))

(l4*sind(gamma)+h1*cosd(gamma)) (l3*cosd(gamma)-h1*sind(gamma))

(1)*(l3*sind(gamma)+h1*cosd(gamma)) (-1)*(l1*cosd(gamma)-h3*sind(gamma))

(-1)*(l1*sind(gamma)+h3*cosd(gamma)) 0 0

0 0 0 0 0 0 0 -1 0 0 0 1

0 0 0 0 0 0 -1 0 0 0 1 0

0 0 0 0 0 0 0 0 0 0 (-1)*lcyl2*sind(alfa)

(1)*lcyl2*cosd(alfa)

0 0 0 0 0 0 0 0 0 1 0 -1

0 0 0 0 0 0 0 0 1 0 -1 0

0 0 0 0 0 0 0 0 0 0 (l5*sind(beta)+h1*cosd(beta))

(-1)*(l5*cosd(beta)-h1*sind(beta))];

B = [Fmcyl1 0 lmcyl1*Fmcyl1*cosd(phi) Fmlink1 0

Fmlink1*lmlink1*sind(gamma) Fmcyl2 0 lmcyl2*cosd(alfa)*Fmcyl2

Fmlink2+Fload 0 lmlink2*cosd(beta)*Fmlink2+l2*cosd(beta)*Fload]';

R = A\B;

R_adams = [1254.4124 8061.3551 1254.4124 9229.7261 1254.4124

9170.8661 -8439.2676 -1781.8898 -8439.2676 -2646.1508 -8439.2676

-1899.6098];

disp(['F1x = ',num2str(R(1)),'N',' Fadams = ',num2str(R_adams(1)),'N'])

disp(['F1y = ',num2str(R(2)),'N',' Fadams = ',num2str(R_adams(2)),'N'])











61

APPENDIX D: MATLAB PLOT

clear all, close all, clc

R_adams = abs([ 0.0 1254.4124 8061.3551 1254.4124 9229.7261 1254.4124

9170.8661 -8439.2676 -1781.8898 -8439.2676 -2646.1508 -8439.2676 -

1899.6098

0.2 1218.7334 7947.6974 1218.7334 9116.0684 1218.7334 9057.2084 -

7499.0776 -1789.6962 -7499.0776 -2653.9572 -7499.0776 -1907.4162

0.4 1191.0887 7838.4851 1191.0887 9006.8561 1191.0887 8947.9961 -

6790.3248 -1779.155 -6790.3248 -2643.416 -6790.3248 -1896.875

0.6 1170.6497 7733.4704 1170.6497 8901.8414 1170.6497 8842.9814 -

6232.6111 -1758.8692 -6232.6111 -2623.1302 -6232.6111 -1876.5892

0.8 1156.6765 7632.2403 1156.6765 8800.6113 1156.6765 8741.7513 -

5780.1721 -1733.3556 -5780.1721 -2597.6166 -5780.1721 -1851.0756

1.0 1148.5146 7534.3309 1148.5146 8702.7019 1148.5146 8643.8419 -

5404.7261 -1705.1629 -5404.7261 -2569.4239 -5404.7261 -1822.8829

1.2 1145.5865 7439.275 1145.5865 8607.646 1145.5865 8548.786 -

5087.6994 -1675.8021 -5087.6994 -2540.0631 -5087.6994 -1793.5221

1.4 1147.3809 7346.6224 1147.3809 8514.9934 1147.3809 8456.1334 -

4816.3088 -1646.2003 -4816.3088 -2510.4613 -4816.3088 -1763.9203

1.6 1153.4435 7255.9486 1153.4435 8424.3196 1153.4435 8365.4596 -

4581.4232 -1616.939 -4581.4232 -2481.2 -4581.4232 -1734.659

1.8 1163.3681 7166.856 1163.3681 8335.227 1163.3681 8276.367 -

4376.3204 -1588.3875 -4376.3204 -2452.6485 -4376.3204 -1706.1075

2.0 1176.7896 7078.9737 1176.7896 8247.3447 1176.7896 8188.4847 -

4195.9269 -1560.7807 -4195.9269 -2425.0417 -4195.9269 -1678.5007

2.2 1193.3777 6991.955 1193.3777 8160.326 1193.3777 8101.466 -

4036.3329 -1534.2668 -4036.3329 -2398.5278 -4036.3329 -1651.9868

2.4 1212.8313 6905.4753 1212.8313 8073.8463 1212.8313 8014.9863 -

3894.4717 -1508.9372 -3894.4717 -2373.1982 -3894.4717 -1626.6572

2.6 1234.8739 6819.2291 1234.8739 7987.6001 1234.8739 7928.7401 -

3767.9017 -1484.8457 -3767.9017 -2349.1067 -3767.9017 -1602.5657

2.8 1259.2499 6732.9275 1259.2499 7901.2985 1259.2499 7842.4385 -

3654.6545 -1462.0212 -3654.6545 -2326.2822 -3654.6545 -1579.7412

3.0 1285.7206 6646.2956 1285.7206 7814.6666 1285.7206 7755.8066 -

3553.1252 -1440.4765 -3553.1252 -2304.7375 -3553.1252 -1558.1965

3.2 1314.062 6559.0698 1314.062 7727.4408 1314.062 7668.5808 -

3461.994 -1420.2144 -3461.994 -2284.4754 -3461.994 -1537.9344

3.4 1344.0612 6470.9962 1344.0612 7639.3672 1344.0612 7580.5072 -

3380.1672 -1401.2311 -3380.1672 -2265.4921 -3380.1672 -1518.9511

3.6 1375.5146 6381.8277 1375.5146 7550.1987 1375.5146 7491.3387 -

3306.7331 -1383.5202 -3306.7331 -2247.7812 -3306.7331 -1501.2402

3.8 1408.2256 6291.3227 1408.2256 7459.6937 1408.2256 7400.8337 -

3240.9286 -1367.0739 -3240.9286 -2231.3349 -3240.9286 -1484.7939

4.0 1442.002 6199.2425 1442.002 7367.6135 1442.002 7308.7535 -

3182.1133 -1351.8852 -3182.1133 -2216.1462 -3182.1133 -1469.6052

4.2 1476.655 6105.3498 1476.655 7273.7208 1476.655 7214.8608 -

3129.7495 -1337.9492 -3129.7495 -2202.2102 -3129.7495 -1455.6692

4.4 1511.9964 6009.4065 1511.9964 7177.7775 1511.9964 7118.9175 -

3083.3869 -1325.2637 -3083.3869 -2189.5247 -3083.3869 -1442.9837

62

4.6 1547.8369 5911.1718 1547.8369 7079.5428 1547.8369 7020.6828 -

3042.6502 -1313.8303 -3042.6502 -2178.0913 -3042.6502 -1431.5503

4.8 1583.9847 5810.4005 1583.9847 6978.7715 1583.9847 6919.9115 -

3007.23 -1303.6553 -3007.23 -2167.9163 -3007.23 -1421.3753

5.0 1620.2427 5706.8401 1620.2427 6875.2111 1620.2427 6816.3511 -

2976.875 -1294.7503 -2976.875 -2159.0113 -2976.875 -1412.4703

5.2 1656.4067 5600.2292 1656.4067 6768.6002 1656.4067 6709.7402 -

2951.3872 -1287.1332 -2951.3872 -2151.3942 -2951.3872 -1404.8532

5.4 1692.2631 5490.2944 1692.2631 6658.6654 1692.2631 6599.8054 -

2930.6176 -1280.8289 -2930.6176 -2145.0899 -2930.6176 -1398.5489

5.6 1727.586 5376.7477 1727.586 6545.1187 1727.586 6486.2587 -

2914.4639 -1275.8703 -2914.4639 -2140.1313 -2914.4639 -1393.5903

5.8 1762.1342 5259.2828 1762.1342 6427.6538 1762.1342 6368.7938 -

2902.8691 -1272.2996 -2902.8691 -2136.5606 -2902.8691 -1390.0196

6.0 1795.6476 5137.5718 1795.6476 6305.9428 1795.6476 6247.0828 -

2895.8214 -1270.1696 -2895.8214 -2134.4306 -2895.8214 -1387.8896

6.2 1827.8433 5011.2601 1827.8433 6179.6311 1827.8433 6120.7711 -

2893.3557 -1269.5453 -2893.3557 -2133.8063 -2893.3557 -1387.2653

6.4 1858.4102 4879.9612 1858.4102 6048.3322 1858.4102 5989.4722 -

2895.5561 -1270.506 -2895.5561 -2134.767 -2895.5561 -1388.226

6.6 1887.0032 4743.2502 1887.0032 5911.6212 1887.0032 5852.7612 -

2902.5603 -1273.1477 -2902.5603 -2137.4087 -2902.5603 -1390.8677

6.8 1913.2355 4600.6558 1913.2355 5769.0268 1913.2355 5710.1668 -

2914.5654 -1277.5864 -2914.5654 -2141.8474 -2914.5654 -1395.3064

7.0 1936.6696 4451.6504 1936.6696 5620.0214 1936.6696 5561.1614 -

2931.8371 -1283.9619 -2931.8371 -2148.2229 -2931.8371 -1401.6819

7.2 1956.8049 4295.6373 1956.8049 5464.0083 1956.8049 5405.1483 -

2954.7204 -1292.4429 -2954.7204 -2156.7039 -2954.7204 -1410.1629

7.4 1973.0633 4131.9353 1973.0633 5300.3063 1973.0633 5241.4463 -

2983.6557 -1303.2332 -2983.6557 -2167.4942 -2983.6557 -1420.9532

7.6 1984.769 3959.7578 1984.769 5128.1288 1984.769 5069.2688 -

3019.1994 -1316.5801 -3019.1994 -2180.8411 -3019.1994 -1434.3001

7.8 1991.1225 3778.186 1991.1225 4946.557 1991.1225 4887.697 -

3062.0517 -1332.7855 -3062.0517 -2197.0465 -3062.0517 -1450.5055

8.0 1991.1656 3586.1332 1991.1656 4754.5042 1991.1656 4695.6442 -

3113.0953 -1352.2203 -3113.0953 -2216.4813 -3113.0953 -1469.9403

8.2 1983.7337 3382.2956 1983.7337 4550.6666 1983.7337 4491.8066 -

3173.448 -1375.3443 -3173.448 -2239.6053 -3173.448 -1493.0643

8.4 1967.3879 3165.0844 1967.3879 4333.4554 1967.3879 4274.5954 -

3244.5368 -1402.7332 -3244.5368 -2266.9942 -3244.5368 -1520.4532

8.6 1940.3191 2932.5292 1940.3191 4100.9002 1940.3191 4042.0402 -

3328.2044 -1435.1166 -3328.2044 -2299.3776 -3328.2044 -1552.8366

8.8 1900.2053 2682.137 1900.2053 3850.508 1900.2053 3791.648 -

3426.8654 -1473.4335 -3426.8654 -2337.6945 -3426.8654 -1591.1535

9.0 1843.9948 2410.6778 1843.9948 3579.0488 1843.9948 3520.1888 -

3543.742 -1518.9121 -3543.742 -2383.1731 -3543.742 -1636.6321

9.2 1767.5634 2113.8506 1767.5634 3282.2216 1767.5634 3223.3616 -

3683.231 -1573.1923 -3683.231 -2437.4533 -3683.231 -1690.9123

9.4 1665.147 1785.7335 1665.147 2954.1045 1665.147 2895.2445 -

3851.5002 -1638.5171 -3851.5002 -2502.7781 -3851.5002 -1756.2371

63

9.6 1528.3502 1417.8329 1528.3502 2586.2039 1528.3502 2527.3439 -

4057.5004 -1718.0437 -4057.5004 -2582.3047 -4057.5004 -1835.7637

9.8 1344.2896 997.3179 1344.2896 2165.6889 1344.2896 2106.8289 -

4314.7888 -1816.3751 -4314.7888 -2680.6361 -4314.7888 -1934.0951

10.0 1091.7973 503.4438 1091.7973 1671.8148 1091.7973 1612.9548

-4645.0569 -1940.5153 -4645.0569 -2804.7763 -4645.0569 -2058.2353]);

stroke = [240:(545-240)/50: 545]';

stroke2 = [830:-(830-470)/50: 470]'

plot(stroke,R_adams(:,2),'k',stroke,R_adams(:,3),'b',stroke,R_adams(:,4),'m',

stroke,R_adams(:,5),'r',stroke,R_adams(:,6),'--k',stroke,R_adams(:,7),'--

b',stroke,R_adams(:,8),'--m',stroke,R_adams(:,9),'--

r',stroke,R_adams(:,10),'-.k',stroke,R_adams(:,11),'-

.b',stroke,R_adams(:,12),'-.m',stroke,R_adams(:,13),'-.r','LineWidth',1.5)

lgd =

legend('F_1_x','F_1_y','F_2_x','F_2_y','F_3_x','F_3_y','F_4_x','F_4_y','F_5_x

','F_5_y','F_6_x','F_6_y')

set(gca,'FontName','Times New Roman')

lgd.FontAngle = 'Italic'

lgd.FontWeight = 'Bold'

xlabel('Stroke length, Cylinder 1 [mm]')

ylabel('Force [N]')

axis([240 545 0 10000])

title('Force as function of the stroke length of Cylinder 1')

cylinder1 = sqrt(R_adams(:,5).^2+R_adams(:,6).^2)

cylinder2 = (sqrt(R_adams(:,7).^2+R_adams(:,8).^2))

figure

subplot(2,1,1)

plot(stroke,cylinder1,'k','LineWidth',1.5)


ylabel('Force [N]')

legend('Cylinder 1')

axis([240 545 min(cylinder1) max(cylinder1)])

title('Resulting forces in the cylinders')


subplot(2,1,2)

plot(stroke2,cylinder2,'k','LineWidth',1.5)

set(gca,'xdir','reverse')


ylabel('Force [N]')

axis([470 830 min(cylinder2) max(cylinder2)])

legend('Cylinder 2')

max(cylinder1)

max(cylinder2)


65

APPENDIX E: FEM Convergence Test

Table 17 Link arm 1 convergence test

Mesh size [mm]

Link [MPa]

Hinge

[MPa]

10 86.594 125.95

9 106.63 129.01

8 106.07 133.06

7 62.561 140.64

6 127.96 118.85

5 105.88 122.79

4 105.45 137.62

3 98.871 114.48

66

Table 18 Link arm 2 convergence test

Mesh size [mm]

Link arm [MPa]

Hinge

[MPa]

10 73.893 125.2

9 75.573 131.59

8 68.738 162.82

7 84.048 169.41

6 81.831 163.23

5 81.248 177.34

4 97.826 171.78

3 217 124.51

67

APPENDIX F: Fatigue Analysis

Following settings was used in the fatigue mode in ANSYS, Figure 62.

Figure 62 Settings for the fatigue analysis

With these settings following results were achieved. The result of Link arm 1 is shown in Figure

63 and the result of Link arm 2 is shown in Figure 64. The requirement specification specifies

that the device should work for 6 years. If the machine works continuously none stop for 24

hours and 7 days a week for 6 years then the link arm system would have to repeat the cycle of

hanging a hanger with cables 26240 times.

Link arm 1 will not be subjected to fatigue according to the analysis during the time of operation.

Figure 63 Fatigue of Link arm 1

68

The limit towards fatigue in Link arm 2 is however closer but will hold through the lifetime

according to the results.

Figure 64 Fatigue of Link arm 2

69

APPENDIX G: Worst Case FEM Analysis

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