Torque converter with lock-up clutch having a flow-restraining elastic

Abstract

A torque converter is provided with a front cover (2) at the power input side, an impeller, a turbine (4), a stator (5), a piston (22), a plate spring (35), and a friction facing (36). The piston (22) is disposed in the space formed between the front cover (2) and the turbine (4) to divide the space into first and second hydraulic chambers (A) and (B). The first hydraulic chamber (A) is located between the piston (22) and the front cover (2), while the second hydraulic chamber (B) is located between the piston (22) and the turbine (4). The piston (22) can move close to and away from the front cover (2) by the pressure difference between the first hydraulic chamber (A) and the second hydraulic chamber (B). The piston (22) is opposite the front cover (2) and engages to the turbine (4) to enable the torque to be transmitted. The plate spring (35) is fixedly coupled to the piston (22) and is opposite the front cover (2). The friction facing (36) is fixedly coupled to the plate spring (35) and is located adjacent to the front cover (2). In the state where the piston (22) is disposed closest to the turbine (4), and at least when substantially no pressure difference exists between the first and second hydraulic chambers (A) and (B), the friction facing (36) is pressed against the front cover (2) by the plate spring (35) to increase the moving speed of the piston (22) when the lock-up clutch (7) of a torque converter (1) being engaged.