New Model of a CVT Rocker-Pin Chain With Exact Joint Kinematics

Abstract

The improvement of continuously variable transmissions (CVTs) is a challenging task. Detailed dynamic models of the system are needed for the optimization process. This paper introduces a new model of a rocker-pin chain, which is the central part of a chain CVT. During the derivation of the equations of motion, special attention is turned on the exact description of the joint kinematics. An interesting method to speed up the numerical simulation of the chain drive is introduced, which takes into account the special structure of the mass matrix. Simulation results show the strong influence of the geometry of the rocker-pin joints on the dynamics of the whole gear. Further reasonable gear efficiencies can be estimated for arbitrary joint geometries. This model is an excellent basis for further work on optimization of the CVT chain.

On non-smooth multibody dynamics

“…In the meantime, we are able to optimize rocker pin chains applying a new mathematical optimization algorithm called 'implicit filtering'. 63 Computing times in the order of magnitude of some hours are reasonable, and the results for a certain type of an industrial chain are very promising.…”

“…Two types of torques are taken into consideration, the restoring torques from the non-symmetric local pressure distributions generated in the contacts pins/pulley and from the kinematical process of rolling without sliding of rocker pins on rocker pins. 35,63 The dynamics of the rocker pin chain system as a whole will be represented by a set of the equations of motion together with a second set of relative kinematics in normal and tangential directions and finally the set of all complementarity equations. This is written as…”

Study of power loss in chain continuously variable transmissions (CVT) using a geometric model (Translated)

“…Performance predictions of chain-type CVTs such as vibration, noise, and strength have been studied in various ways in the past, such as studies using multibody models and studies using continuum models (Sedlmayr et al, 2002, Pfeiffer, 2005Neumann et al, 2006aNeumann et al, , 2006bSrivastava and Haque, 2008a, 2008b, 2009a, 2009bCarbone et al, 2005Carbone et al, , 2010Yildiz et al, 2016). There is also a research example in which the deformation of the pulley was considered using FEM analysis, and the power loss caused by the chain slipping in the pulley in the radial direction was investigated (Tenberge, 2004).…”