Patent ID: 6336323
Filing Date: 2002-01-08
Classification: B60T,F16D

Abstract:
A brake for a hydraulic motor having a fixed portion and a rotating portion rotatable relative to the fixed portion, the brake comprising:one or more fixed friction plates connected to the fixed portion, and movable in an axial direction; one or more rotating friction discs connected to the rotating portion, and movable in the axial direction and rotatable together with the rotating portion; a spring for exerting a pressing force to said fixed and rotating friction plates to frictionally contact these friction plates together; a releasing piston, disposed between said spring and said fixed and rotating friction plates, for transmitting the pressing force exerted by said spring to the friction plates; a releasing passage for introducing a driving fluid fed to the hydraulic motor to said releasing piston to move said releasing piston away from said fixed and rotating friction plates, thereby releasing the frictional contact between the fixed and rotating friction plates; a braking piston supported on said fixed portion and movable in the axial direction; and a braking passage for introducing a high pressure fluid to said braking piston to press said braking piston against said fixed and rotating friction plates, there by frictionally contacting the fixed and rotating friction plates together.