Abstract: A braking apparatus for a hydraulic motor (20) having a rotary component (21) includes a rotary side friction plate (22) coupled to the rotary component of the hydraulic motor, a fixed side friction plate (23) coupled to a fixed component of the hydraulic motor, and a braking cylinder assembly (24) having a piston (25), a spring (26) and a piston pressure receiving chamber (27). The piston is energizable by the spring to move in a braking direction for bringing the fixed side and the rotary side friction plates into a pressure contact, whereas the piston pressure receiving chamber can be be supplied with pressure fluid to displace the piston in a braking release direction, thereby separating the fixed side friction plate and the rotary side friction plate from each other. An operating valve (41, 42) supplies pressure fluid into the hydraulic motor, and a hydraulic pilot valve (52, 53) provides pilot pressure fluid for use to switch the operating valve.

Abstract: A braking apparatus for a hydraulic motor has a housing and a cylinder block. The apparatus includes fixed side frictional plates mounted to the housing and movable side frictional plates mounted to the cylinder block. In addition, a piston for pressing the fixed side frictional plates against the movable side frictional plates is also provided. A spring for thrusting the piston to move in a first direction thus tending to establish a first state in which the two sets of frictional plates are pressed together is also included. Furthermore, the apparatus includes a piston driving pressure receiving chamber disposed between the housing and the piston for thrusting the piston to move in a second direction under a pressure that is introduced into the piston driving pressure receiving chamber to establish a second state in which the two sets of frictional plates are separated from each other.