Review on Overload Torque Limiter with Electromechanical Clutch for Timer Belt Spindle Drive

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Review on Overload Torque Limiter with Electromechanical Clutch for Timer Belt Spindle Drive Mr. Nitesh A. Kulkarni 1, Prof. V. R. Gambhire 2 1 M.E. Student, Mechanical department, TKIET, warananagar, Kolhapur, 2 Prof.

1 Review on Overload Torque Limiter with Electromechanical Clutch for Timer Belt Spindle Drive Mr. Nitesh A. Kulkarni 1, Prof. V. R. Gambhire 2 1 M.E. Student, Mechanical department, TKIET, warananagar, Kolhapur, 2 Prof., 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 jamup 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. 1.1 Actual working of the overload slip ball clutch- The overload slipping ball clutch is an safety device used in the transmission line to connect the driving and driven elements such that in case of occasional overload the clutch will slip there by disconnecting the input and output members. This protects the transmission elements from any breakage or damage. For a particular loading conditions the clutch is preset to set the cylindrical body for slipping at a different overload, it is simply mounted on output member by means of a key. Casing is adjusted in the appropriate direction, during which the balls will remain pressed against the serrations; thus setting operation is simple, rapid and reliable. The clutch is there connected to the output member or load. When the input shaft is in rotation through the reduction pulley and motor, the base flange is rotated, along with it the balls pressed against Vee - serration also rotate. This motion is transmitted through springs; plunger to the cylindrical body which then rotates the output All Rights Reserved 158

When the load on the output shaft exceeds the preset design overload the resistance of the balls to more in direction of motion of base flange, there by balls start slipping in the Vee serrations.

2 When the load on the output shaft exceeds the preset design overload the resistance of the balls to more in direction of motion of base flange, there by balls start slipping in the Vee serrations. At one point the balls completely come out of the serrations into open space in base flange thereby disconnecting the base flange and the cylindrical body. Thus the input shaft keeps rotating where as the output shaft comes to stand stop. The overload value at which clutch slips can be designed and preset by moving the casing in either direction of the cylindrical body. To increase the overload value; move casing towards the base flange where as to reduce the overload; move the casing away from the base flange. The casing can be locked in position by means of the lock nut. Figure 1- Schematic Layout Of Overload Torque Limiter With Electromechanical Clutch 1.2 Features of Ball Clutch a) Electromechanical disengagement so that drive can be temporarily disengaged for process inspection or other activity. b) The torque limiter can be set over a range of torques so that the machine operator can set it to desired value for given application unlike the conventional clutches that are factory set. c) The 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 All Rights Reserved 159

3 assembly and will save considerable amount of downtime of process as compared to the conventional clutch. d) 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. II. LITERATURE SURVEY 1. Guy James Burlington, et.al. [1] have done invention related to clutch mechanism, such as that employed in conjunction with the drive of agitator of a vacuum cleaner. Vacuum cleaners typically comprise a downwardly direction dirty air inlet arranged in the cleaner head or a floor tool through which dirty air is sucked, by means of a motor driven fan, into dirt and dust separation apparatus. An agitator, such as a brush bar, may be arranged in the mouth of the dirty air inlet so as to agitate the fibers of a carpet over which the vacuum cleaner is passed. A problem which may encounter with vacuum cleaners having an agitator is that, on occasion, the agitator may become jammed by becoming entangled with objects on the floor surface. Where the agitator is driven by vacuum motor sensing of such overload condition is more difficult. Thus actuator may be arranged to interrupt torque when the relative speed rise above predetermined value. 2. Charles W. Yeiser, et.al. [2] have work done the torsional design and analysis process associated with revamping a 7000 hp synchronous motor-driven compressor train with a 8000 hp synchronous motor driver. The paper details multiple issues associated with revamping the compressor drive train, including the selection of the replacement driver and low-speed coupling assembly, torsional vibration analysis, and the mechanical operation of the controlled slip clutch mechanism. The main objective in revamping the compressor trains was to extend the life of the plant while being able to operate at substantially higher than design production. The second objective was to reduce the amount of electrical power consumed per unit volume of product produced. The third objective was to reduce the amount of projected maintenance for the compressor train. The fourth objective was to minimize the amount of modification required to install the new motors. The fifth objective was to design the revamped compressor train for 5000 starts. The final objective was to minimize the risk of the revamp. The first three objectives were achieved by using a higher horse power solid pole rotor synchronous motor whose design was optimized for this application. The fourth objective was achieved by having the motor frame designed to fit the existing sole plate sand duplicating all-important dimensions of the original motor. The fifth and final objective was achieved by using the controlled slip clutch coupling. Accordingly, the revamp met the objectives and is considered a success. 3. NicolaeEftimie [3] has discussed that by taking into considerations both the proposed kinematic and dynamic modeling, and the numerical simulations presented, & concluded that the most important parameters, which influence in a major manner the safety clutches working are; the ratio between the inertia moments at the driven and driving parts, the spring s type and consequently their rigidity and the pretension springs force. The proper adjustment of the inertia moment to the driven part of the clutch to the possibility of taking over the medium value shocks. This situation is necessary in case of the clutch assembling in the frame of the striking machines transmissions. Finally, it must be remarked the fact, the proposed computer simulations were made with a view of the main characteristics identification of the safety clutches with implications in kinematic optimization and more, their dynamic All Rights Reserved 160

4 4. Duane W. Woltjen [4] has done invention relates to shaft coupling means, and more specifically pertains to a bearing interconnecting torque limiting overload coupling for preventing shaft rotation at forces exceeding the designed torque for the operating machinery. The construction of a torque limiting device for furnishing a totally mechanically operates overload coupling for, as previously mention, attaching rotating and rotatable part of machinery together. And, due to the unique construction of the interrelated component of this invention, the coupling can be easily adjusted, to within relatively precise limits of the quantity of force or torque that may be accommodated by such machinery before disengagement of the coupling occurs, therefore functioning as a safety mechanism for the industrial machinery and tools. 5. Donald L. Miller, et.all. [5] have worked on Electric overload clutch and discussed that an electromagnetic clutch having an overtorque triggered release which allows reengagement of the torque transmitting members without reducing clutch speed. when overload occurs, the initial slippage of the torque transmitting members cams them apart, reversing the spring-electromagnetic force balance to force the axially movable torque transmitting member away from the axially stationary torque transmitting member. Electrical switching means, sensitive to torque and speed, are also provided to change the state of current flow in the electromagnetic clutch. 6. Thomas C. Kilwin [7] has discussed about invention relates generally to means for coupling machinery components together, and more specifically pertains to an improved torque limiting clutch that interconnects principally between the speed reducer and machinery it operates in order that operational power to machinery can be curtailed upon encountering excessive impeding forces that exceed the acceptable clutch designed torque. III. OBJECTIVES 3.1 Objectives 1. To reduce machine down time so as to improve productivity. 2. To run the system smoothly. 3. To reduce maintenance cost. 3.2 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. [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 Design Calculations and Process Sheets a) Design of various components such as input shaft, bearings, output shaft, V Belt drive, selection of timer belt, base flange, cylinder body, plunger, spring etc. b) Sample process sheet of input shaft, output shaft, plunger, base flange, cylinder body manufacturing with details of all the All Rights Reserved 161

5 3.2.2 Experimentation and testing 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 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 such as 1. Input Shaft, 2. Plunger, 3. Output shaft, 4. Cylinder body. IV. 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 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 NicolaeEftimie, Dynamic Simulation Of The Safety Clutches With Balls, Transilvania University of Brasov Faculty of Technological Engineering Romania Duane W. Woltjen, Torque Limiting Overload Coupling, United States Patent Donald. Miller, Horseheads. N. Y, Electric Overload Clutch,United States Patent Thomas C. Kilwin, Torque Limiting Clutch, United States patent 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 All Rights Reserved 162

REVIEW ON OVERLOAD TORQUE LIMITER WITH ELECTROMECHANICAL CLUTCH FOR TIMER BELT SPINDLE DRIVE

REVIEW ON OVERLOAD TORQUE LIMITER WITH ELECTROMECHANICAL CLUTCH FOR TIMER BELT SPINDLE DRIVE Abstract Chaitanya G Burande 1, Sanjaysingh Vijaysingh Patil 2 1 PG Student, burandechaitanya5@gmail.com 2 Assistant