Design consideration and potential of the Milner CVT

The Milner continuously variable transmission (MCVT) is a transmission device based on rolling contacts analogous to those found in an angular contact roller bearing. The MCVT is particularly applicable to very high power density applications or those with very demanding packaging constraints, due primarily to the existence of multiple traction contacts on each of the rolling elements. Initial testing of a 12kW MCVT prototype was undertaken in 1999 with promising results [1]. This lead to the further development and testing of a 2 nd prototype MCVT rated to 60kW, however the design target of this device was not achieved and performance was hampered by a loss of traction capacity compared to the design specification. The work presented in this paper highlights work undertaken on a full dynamic simulation and analysis of the MCVT and identifies the failure mode of the 2nd MCVT prototype and as a result a redesign of this device has been undertaken such that it can obtain its original design targets.