Innovative and Highly Efficient Clutch System for Multispeed BEV with Highspeed Powertrains

According to the state of the art in research and technology, previous clutch systems based on multidisc design are not suitable for shiftable BEVs with highspeed transmissions up to 30,000 rpm in order to meet the higher requirements with regard to controllability at high clutch input speeds, efficiency and freedom from drag torque. The consortium project “Highspeed Clutch” was started with the IPEK—Institute of Product Engineering and transmission suppliers Mubea Tellerfedern GmbH, Miba Frictec GmbH and Kaco GmbH + Co. KG with the aim of developing and prototyping friction clutch concepts for electric vehicles with a multi speed transmission. The focus is on electric drives with high speeds of up to 30,000 rpm. This article presents the clutch concept for multispeed electric drives that was developed in the project. Two designs of friction system for high sliding speeds and combination and arrangement of the subsystems shift piston, separating spring and sealing system are presented in order to improve the system behaviour in the synchronization phase as well as in the open phase. To increase efficiency, the clutch concept is equipped with an innovative latching system that is based on the ballpoint pen mechanism and requires no energy when closed. This paper presents the first results of the functional verification. Furthermore, a novel release bearing in the form of a plain bearing was developed in order to realize actuation by a non-rotating shift piston at high clutch input speeds. In this lecture the test bench concept and the test specimen variants, test parameters and lubrication concepts are described also.