Clearance and friction-induced dynamics of chain CVT drives

Abstract A continuously variable transmission (CVT) is an emerging automotive transmission technology that offers a continuum of gear ratios between desired limits. A chain CVT is a friction-limited drive as its performance and torque capacity rely significantly on the friction characteristic of the contact patch between the chain and the pulley. Moreover, such a CVT is susceptible to clearance formation due to assembly defects or extensive continual operation of the system, which further degrades its performance and leads to early wear and failure of the system. The present research focuses on developing models to understand the influence of clearance and different friction characteristics on the dynamic performance of a chain CVT drive. A detailed planar multibody model of a chain CVT is developed in order to accurately capture the dynamics characterized by the discrete structure of the chain, which causes polygonal excitations in the system. A suitable model for clearance between the chain links is embedded into this multibody model of the chain CVT. Friction between the chain link and the pulley sheaves is modeled using different mathematical models which account for different loading scenarios. The mathematical models, the computational scheme, and the results corresponding to different loading scenarios are discussed. The results discuss the influence of friction characteristics and clearance parameters on the dynamic performance, the axial force requirements, and the torque transmitting capacity of a chain CVT drive.

[1]  Giacomo Mantriota,et al.  Influence of Clearance Between Plates in Metal Pushing V-Belt Dynamics , 2002 .

[2]  Nilabh Srivastava,et al.  Influence of Clearance on the Dynamics of Chain CVT Drives , 2006 .

[3]  Pier Paolo Valentini,et al.  Dynamic Simulation of a Metal Belt CVT Under Transient Conditions , 2002 .

[4]  Nilabh Srivastava,et al.  Using Genetic Algorithms to Identify Initial Operating Conditions for a Transient CVT Model , 2004 .

[5]  Friedrich Pfeiffer,et al.  Spatial Dynamics of CVT Chain Drives , 2002 .

[6]  Heinz Ulbrich,et al.  Analysis of Self-induced Vibrations in a Pushing V-belt CVT , 2004 .

[7]  K.J. Astrom,et al.  Dynamic Friction Models and Control Design , 1993, 1993 American Control Conference.

[8]  Friedrich Pfeiffer,et al.  Multibody Dynamics with Unilateral Contacts , 1996 .

[9]  G. Stavroulakis.  Multibody Dynamics with Unilateral Contacts by Friedrich Pfeiffer and Christoph Glocker, Wiley, New York, 1996 , 1998 .

[10]  Nilabh Srivastava,et al.  On the transient dynamics of a metal pushing V-belt CVT at high speeds , 2005 .

[11]  Friedrich Pfeiffer,et al.  Dynamics of CVT chain drives , 1999 .

[12]  Peter Ravn,et al.  A Continuous Analysis Method for Planar Multibody Systems with Joint Clearance , 1998 .

[13]  Martin Sedlmayr,et al.  Force reduction in CVT chains , 2002 .

[14]  Giuseppe Carbone,et al.  The Influence of Pulley Deformations on the Shifting Mechanism of Metal Belt CVT , 2005 .

[15]  Yutaka Mabuchi,et al.  A STUDY ON THE TORQUE CAPACITY OF A METAL PUSHING V-BELT FOR CVTS , 1998 .

[16]  Peter Tenberge.  Efficiency of Chain-CVTs at Constant and Variable Ratio - A new mathematical model for a very fast calculation of chain forces, clamping forces, clamping ratio, slip, and efficiency , 2004 .

[17]  Jorge Ambrósio,et al.  A Roller Chain Drive Model Including Contact with Guide-Bars , 2004 .

[18]  N. Srivastava,et al.  Influence of friction characteristic on the performance of chain CVT drives , 2006 .

[19]  Friedrich Pfeiffer,et al.  State-of-the-Art of CVT-Modelling , 2004 .

[20]  J. N. Fawcett.  Chain and Belt Drives - A Review , 1981 .

[21]  Nilabh Srivastava,et al.  On the operating regime of a metal pushing V- belt CVT under steady state microslip conditions , 2004 .

[22]  Friedrich Pfeiffer,et al.  Dynamics of high speed roller chain drives , 1996 .

[23]  J. Ambrósio,et al.  Dynamic Analysis for Planar Multibody Mechanical Systems with Lubricated Joints , 2004 .

[24]  D. C. Sun.  Performance Analysis of a Variable Speed-Ratio Metal V-Belt Drive , 1988 .

[25]  D K Longmore,et al.  Modelling of the Steel Pushing V-Belt Continuously Variable Transmission , 1994 .

[26]  Giuseppe Carbone,et al.  EHL visco-plastic friction model in CVT shifting behaviour , 2003 .

[27]  Nilabh Srivastava,et al.  Transient Dynamics of the Metal V-Belt CVT: Effects of Pulley Flexibility and Friction Characteristic , 2007 .