Design & Analysis of Overload Torque Limiter … & Analysis of Overload Torque Limiter with Electromechanical Clutch for Timer Belt Spindle Drive Mr. Nitesh A. Kulkarni1,Prof. V. R

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Design & Analysis of Overload Torque Limiter with Electromechanical

Clutch for Timer Belt Spindle Drive

Mr. Nitesh A. Kulkarni1, Prof. V. R. Gambhire2 1M.E. Student, Mechanical department, TKIET, warananagar, Kolhapur

2Prof., Mechanical department, TKIET, warananagar, Kolhapur

Abstract— Clutches are used to transmit power between two coincident shafts. The positive

engagement between the clutch elements ensures 100% torque transmission. But occasionally the

output shaft may the subjected to a sudden overload which may make the driving motor or engine to

stop, which will lead to burnout of the electric motor. In extreme cases this overload will lead to the

breakage of drive elements or the clutch itself. In order to avoid the damage of the transmission

elements it is necessary that the input and output shafts be disconnected in case of sudden overloads.

Torque-limiters are overload safety devices which provide reliable overload protection. When a jam-

up or excessive loading occurs the torque limiter will reliably and quickly disengage to prevent the

system damage. The clutch transmission elements i.e. the balls will not come out of assembly when

there is overload slipping. This will be an advantage as the clutch can be preset without removing it

from assembly and will save considerable amount of downtime of process as compared to the

conventional clutch. If temporary overload occurs the clutch will slip and remain disengaged only till

the overload is removed thus if the overload is removed while in running condition the clutch shall

automatically engage and start transmitting power. This leads to minimize process down time saving

a considerable amount of man and machine hours wasted due to breakage or presetting as in

conventional clutches.

Keywords— Overload Torque Limiter, Timer Belt, Solenoid, Theoretical (Th.).

I. INTRODUCTION

Whenever an overload occurs in any shaft drive mechanism there are possibilities, Shaft /

coupling/ belt drive may fail or break, Application machine shaft may fail or break, Motor will be

overloaded resulting into electric burn. In any case the system will be damaged, leading to machine

part replacement, increased down time of machine, increased part replacement and maintenance cost.

In order to avoid the damage of the transmission elements it is necessary that the input and output

shafts be disconnected in case of sudden overloads. The isolation of the input driver member i.e.,

motor from the output member is absolutely necessary to avoid damage and it is possible by overload

slip ball clutch.

II. OBJECTIVES

2.1 Objectives

1. To reduce machine down time so as to improve productivity.

2. To run the system smoothly.

3. To reduce maintenance cost.

2.2 Working Methodologies

[a] To carry system design as to number of ball-springs for desired torque capacity.

[b] Design of the groove profile in input base flange.

[c] Design of spring plunger profile.

[d] Selection and geometrical profile of clutch body ball holder.

International Journal of Recent Trends in Engineering & Research (IJRTER) Volume 02, Issue 0X; Month - 2016 [ISSN: 2455-1457]


[e] Selection and design of torque control using plunger and casing arrangement.

[f] Selection of timer belt drive for open belt drive.

[g] Mechanical design: This part includes the design and development of springs, selection of

suitable drive motor, strength analysis of components under the given system of forces.

[h] The critical components of assembly input pulley, torque limiter input shaft, input base flange,

plunger, cylindrical body, output shaft etc., components will be designed using conventional

theories of failure using various formulae, 3-D models of the above parts will be developed using

modeling software and meshing –analysis will be done, the result of stress produced will be

validated using Finite element Analysis.

2.3 Mechanical Design -

In mechanical design the components are listed down and stored on the basis of their procurement in

two categories,

Design parts

Parts to be purchased. Approach To Mechanical Design Of ‘Overload Slipping Ball Clutch’

In design the parts we shall adopt the following approach;

a) Selection of appropriate material.

b) Assuming an appropriate dimension as per system design.

c) Design check for failure of component under any possible system of forces.

III. FINITE ELEMENT ANALYSIS

3.1 FEA Analysis

3-D cad modeling using modeling software and analysis for strength of critical components of the

overload slipping ball clutch using finite element analysis software like ANSYS.

3.2 Analysis Of Input Shaft By Using Ansys Software.

Import IGES input shaft cad file into ansys design moduler.

Fig. 3.1 Import IGES input shaft cad file into ansys design moduler.



Meshing is done with 0.5mm mesh size & tetrahedron element selected.

Fig. 3.2 Meshing.

Apply boundary conditions & loading condition to input shaft.

Fig. 3.3 Apply boundary conditions & loading conditions.

Solve solution & observe the result.

Total deformation in the input shaft is 0.0001469 maximum.

Fig. 3.4 Total deformation.



Equivalent (Von-mises) stress is 1.4329 Mpa.

Fig. 3.5 Equivalent (Von-mises) stresses.

Total deformation & equivalent von mises stress is less than material yield strength so input shaft is

safe.

3.3 Analysis of plunger :-

Meshing is done with 1mm mesh size.

Fig. 3.6 Meshing.



Apply boundary conditions & loading condition to plunger.



Fig. 3.8 Normal stresses.

Maximum normal stress induced in plunger is 0.0161MPa.




Maximum total deformation in plunger is 6.507e-6 which is negligible. Analytical stress &

Theoretical stress in plunger is less than yield stress material so plunger is safe.

Theoretical stress N/mm2 Analytical stress N/mm2

0.0153 N/mm2 0.0161 N/mm2

3.4 Analysis of Output shaft:-

Same analysis procedure is carried out for outshaft & observe the result.



Maximum total deformation in plunger is 0.0001482 which is very less. Maximum von mises stress

is 1.567MPa which is less than yield strength of material so output shaft is safe.



3.5 Analysis of Cylinder Body :-

Meshing is done with 1mm mesh size.

Fig. 3.12Meshing.

Apply boundary conditions & loading condition to cylinder body.







Maximum total deformation 3.1423e-6 which is negligible. Analytical stress & Theoretical stress in

cylinder body is less than yield stress material so cylinder body is safe.

Theoretical stress N/mm2 Analytical stress N/mm2

0.026 N/mm2 0.023 N/mm2

Table 3.2 Theoretical & analytical stresses

IV. TEST & TRIAL ON OVERLOAD TORQUE LIMITOR.

4.1 PROCEDURE:-

1) Start motor

2) Let mechanism run & stabilize at certain speed.

3) Place the pulley cord on load drum and add 100 gm weight into the pan, note down the output

speed for this load by means of tachometer.

4) Add another 100 gm weight & take reading.

5) Tabulate the readings in the observation table.

6) Plot Load Vs Torque characteristic.

Load Vs Power characteristic.

4.2 calculation for each load & each speed is calculated.

Sr No. LOAD

(Gms)

SPEED

(Rpm)

TORQUE

(N-mm)

POWER

(Watt)

1 100 1375 12.26 1.68

2 200 1282 24.52 3.22

3 300 1254 36.78 4.72

4 400 1200 49.05 6.15

5 500 1184 61.31 7.56

6 600 1157 73.57 8.91

7 700 1103 85.83 9.91

8 800 990 98.1 10.15

9 900 950 110.36 10.97

10 1000 925 122.62 11.81

Table 4.1 Calculated torque, power.



Fig. 4.1 Load Vs Toque Graph.

Fig. 4.2 Load Vs Power Graph.

V. CONCLUSION

As explained in the relevance overload torque limiter with electromechanical clutch for shaft drive

mechanism was design and devolved successfully, by taking various trials using different weights

and following conclusion is drawn.

Designed overload torque limiter clutch transmit positive torque and by using it, shaft coupling, belt

drive, motor part failure is avoided. The torque limiter can be set over a range of torque values so

that the machine operator can set it to desired value for given application unlike the conventional

clutches. If temporary overload occurs the clutch will slip and remain disengaged only till the

overload is removed thus if the overload is removed while in running condition the clutch shall

automatically engage and start transmitting power. This leads to minimize process down time saving

a considerable amount of man and machine hours wasted due to breakage or presetting as in

conventional clutches. Due to provision of electromechanical disengagement the drive can be

temporarily disengaged for process inspection or other activity. It also act as a safety device for

system.

Overload torque limiter is useful in industry field for pump drive mechanism, compressor drive

mechanism etc.

ACKNOWLEDGMENT

I would like to express my deep sense of gratitude to Prof. V. R. Gambhire for their valuable

contribution in developing the IJRTER article. I am indebted to him for helping to select my project

and providing guidance throughout the completion of my project.

REFERENCES 1. Guy James Burlington, Martin David Townsend, “Clutch Mechanism”,United States Patent 2005.

0

50

100

150

100 200 300 400 500 600 700 800 900 1000TOR

QU

E in

N-m

m

LOAD in grams

TORQUE

TORQUE

0

5

10

15

100 200 300 400 500 600 700 800 900 1000PO

WER

in W

att

LOAD in grams

POWER

POWER



2. Charles W. Yeiser, Volker Hütten, AkramAyoub&Robert Rheinboldt, “Revamping A Gas Compressor Drive Train

From 7000 To 8000 Hp With A New Synchronous Motor Drive And A Controlled Slip Clutch

Mechanism”,Proceedings Of The Thirty-Fifth Turbomachinery Symposium 2006.

3. NicolaeEftimie, “Dynamic Simulation Of The Safety Clutches With Balls”, Transilvania University of Brasov

Faculty of Technological Engineering Romania 2007.

4. Duane W. Woltjen, “Torque Limiting Overload Coupling”, United States Patent 1977.

5. Donald. Miller, Horseheads. N. Y, “Electric Overload Clutch”,United States Patent 1971.

6. Thomas C. Kilwin, “Torque Limiting Clutch”, United States patent 1988.

7. www.ime.rwth-aachen.de/index.php

8. Andrew Lechner, “Servo Rated Ball-Detent Torque Limiter” Design news (September-2013 Issue).

9. V.B. Bhandari, “Design Of Machine Elements”, Tat McGraw Hill Publication Company Limited, third edition.

10. Holbrook L. Horton, “Ingenious Mechanisms For Designers And Inventers”, Industrial Press Inc. 200 Madison

Avenue New York, New York 10016-4078(VOLUME-iii).

http://www.ime.rwth-aachen.de/index.php

Documents

Design & Analysis of Overload Torque Limiter … & Analysis of Overload Torque Limiter with Electromechanical Clutch for Timer Belt Spindle Drive Mr. Nitesh A. Kulkarni1,Prof. V. R