Optimisation of a CVT-Chain

1. Abstract In order to account for current and future requirements regarding the further improvement of the dynamical behaviour of a chain CVT (Continuous Variable Transmission) optimisation methods are substantial. The primary focus lies on the chain, which is the central part of the gear. In this work a concept to deal with this challenging task is introduced, leading to an optimisation tool for CVTs. First of all, a detailed dynamical model of the CVT is necessary to estimate the performance of the gear using numerical simulation techniques. The optimisation problem arising from the aim to optimise CVTs is identified in the next step. This includes the formulation of a target function quantifying the property which has to be optimised. For its evaluation simulated data is used. The optimisation problem is analysed in order to identify the requirements for a suitable optimisation algorithm. Implicit filtering will turn out to be the method of choice. For the implementation of complicated optimisation goals, a class of target functions is introduced. Therewith a tool for optimising CVTs is developed, which basically consists of the numerical simulation, the optimisation algorithm and the class of target functions. Its capability is shown by reducing the noise emission of a CVT which is achieved by obtaining optimal values for certain geometry parameters of the chain.