On the working administration of metal pushing V-belt CVT under relentless state microslip conditions

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2004 International CVT Congress, CA, USA On the working administration of metal pushing V-belt CVT under unfaltering state microslip conditions SAE #: 2004-34-2851 Nilabh Srivastava Imtiaz Haque Department of Mechanical Engineering Clemson University September 24, 2004

Introduction to CVT (Continuously Variable Transmission) Research Objective Literature Review Model Development Results Conclusion Future Work & Recommendations Presentation Outline

Introduction Metal belt structure Metal V-belt CVT

Research Objective Research Focus: Develop model to catch dynamic communications in a metal V-belt CVT under enduring state microslip conditions Study the impact of stacking conditions (torque and powers) on belt slip Study belt slip conduct under microslip conditions i.e. because of hole between belt components Investigate working administration of the CVT for productive torque transmission (i.e. meeting the heap necessities) Predict torque transmitting limit of the CVT Research Support : US ARMY TACOM

Literature Review Related to Slip models & Operating Regime Gerbert, G., 'Belt Slip – A brought together approach', ASME J. of Mechanical Design, Vol. 118, 1996 Sun, D. C., 'Execution examination of a variable speed-proportion metal V-belt drive', Transactions of ASME, Mechanisms, Transmission, and Automotive Design, 110, 1988 Micklem, J. D.. e t al , 'Demonstrating of the steel pushing V-belt constantly factor transmission',Proceedings Inst. Of Mech. Eng., Vol. 208, 1994 Carbone, G., et al , 'Hypothetical Model Of Metal V-Belt Drives During Ratio Changing Speed', ASME Journal of Mechanical Design, Vol. 123, 2000 Kobayashi D., Mabuchi Y., Katoh Y., 'A Study on the Torque Capacity of a Metal Pushing V-Belt for CVTs', SAE Paper 980822, Transmission and Driveline Systems Symposium, 1998 Srivastava,N., Haque, I., "On the transient progression of a metal pushing V-belt CVT at high speeds", International J. of Vehicle Design, ( acknowledged March 2004 ) Srivastava,N., Blouin, V., Haque, I., "Utilizing Genetic Algorithms to recognize introductory working conditions for a transient CVT display", 2004 ASME IMECE, Nov 13-19, 2004 ( acknowledged )

Model Development Assumptions: The pulleys are unbending and there is no misalignment between them E lements and groups are dealt with as a ceaseless belt The focal point of mass of the component and that of the band pack agree Belt length is steady Impending slip conditions exist at all contact surfaces Bending and torsional firmness of the belt are dismissed The component measurements are little in contrast with the pulley radii The aggregate hole between the components is dispersed consistently in the area of zero or low pressure in the belt

ê r dF ê t  a dF d  Model Development Free Body Diagrams: T+dT T Driven Band pack

Model Development Free Body Diagrams: Driven Element

 b dN sin  Element dN  Shaft Axis dF z Pulley Sheave Model Development Free Body Diagrams: Forces of belt component on DRIVEN pulley Free body outlines of the two pulleys yield torque conditions

Model Development Elemental Gap and Slip: Redistribution of natural hole Belt microslip is characterized on the premise of mean crevice [ Kobayashi,1998 ]

Half sheave edge,  15 deg Band pack thickness,  b 3.5 kg/m Element thickness,  e 3 kg/m Belt claim, T o 400 N Driver pulley speed,  500 rpm Center separation, d 0.5 m Coefficient of grating, 0.15 Coefficient of erosion, 0.15 Results Simulation Parameters

Results Belt Compressive Force Profile

Results Transmission proportion versus Driver pivotal Force (5 Nm)

Results Transmission proportion versus Driver hub Force (30 Nm)

Results Transmission proportion versus Most extreme Load Torque

Results Driver side belt slip versus Driver pivotal constrain

Results Driver side belt slip versus Driven pivotal compel

Results Driver side belt slip versus Input Torque

Dynamic connections were noted under relentless state microslip conditions Belt slip was ascertained on the premise of hole redistribution Belt slip is affected by stacking states of torques and strengths Operating administration could be recognized for a given CVT arrangement and determined stacking conditions, under the supposition of microslip and semi static variety in transmission proportion Increasing torque on one of the pulleys expands slip on that pulley, if stacking conditions on the other pulley are kept consistent Increasing hub drive on one of the pulleys diminishes slip on that pulley, if stacking conditions on the other pulley are kept steady Maximum transmittable torque can be evaluated just before the belt experiences net slip Conclusions

Belt can experience both large scale and smaller scale slip, so the working administration ought to be assessed by considering inertial impacts other than the stacking impacts – Srivastava,N., Blouin, V., Haque, I., "Utilizing Genetic Algorithms to distinguish introductory working conditions for a transient CVT demonstrate", 2004 ASME IMECE, Nov 13-19, 2004 ( acknowledged ) Belt slip is not just affected by stacking states of torques and powers, additionally by inertial impacts => The suspicion of steady sliding point over the pulley wrap is disregarded at fast varieties - Srivastava,N., Haque, I., "On the transient elements of a metal pushing V-belt CVT at high speeds", International J. of Vehicle Design, ( acknowledged March 2004 ) The grinding between individual groups in the band pack have been disregarded. In any case, it is assumed that it won't essentially bring about movements in the working administration of the CVT. Kim H., Lee J., 'Investigation of Belt Behavior and Slip Characteristics for a Metal V-belt CVT', Mechanism & Machine Theory,1994 Friction between the surfaces can likewise be demonstrated utilizing elastohydrodynamic grease hypothesis Flexural impacts have been ignored. Notwithstanding, at high speeds and under high stacking conditions, the pulley bundles can experience flexural vibrations, in this manner, affecting working administration of the CVT Real-world analyses should be keep running on a CVT for confirming the consistency of working administration got from the reproduction display. Be that as it may, the aftereffects of the model are in consonance with those got under states of no-heap (i.e. Kobayashi,D., SAE Paper 980822, 1998) Future Work & Recommendations