Fluid transmitting system with lock-up clutch

摘要

A fluid transmitting system includes a lock-up clutch (L) whose clutch piston (19) is disposed between a side cover connected to a pump impeller (6) and a turbine runner (3). A Belleville spring (33) for biasing the clutch piston to a clutch turning-on direction is mounted to a piston hub of the clutch piston slidably carried on a turbine hub (3a) so that the deformation attitude thereof is changed freely. A limiting means (45) is provided between the clutch piston and the turbine runner for limiting the amount of retraction of the clutch piston to a constant value thereby preventing excessive deformation of the Belleville spring, when the clutch piston is retracted in a clutch turning-off direction. Thus, the Belleville spring for biasing the clutch piston of the lock-up clutch in the clutch turning-on direction can exhibit an intrinsic spring characteristic, and moreover the durability of the Belleville spring can be enhanced.