Actuator for torque transmission friction clutch - has shape memory metal element that is electrically heated to cause sudden change in length to operate coupling

摘要

A friction clutch coupling [1] is located between a flywheel [4] on the engine side and a pressure plate that is engaged by a spring plate [2]. The spring plate is subjected to an axial force to control engagement. The actuator [10] operates directly on the spring plate and is at the end of a hollow shaft [9] that locates in a carrier [7] and are coupled together by a bar of shape memory metal [16]. An electrical current applied via a slip ring raises the temperature above the limit for a metallurgical phase change to take place and the length of the bar changes. The clutch action i.e. engage and disengage, can advantageously be controlled via a central control unit, such as an electronic computer.