Brake circuit apparatus for hydraulic motor

摘要

The brake circuit apparatus for a hydraulic motor in a hydraulic circuit system having at least one main hydraulic pump, a hydraulic motor driven by a hydraulic fluid supplied from the main pump and having a rotary shaft, and a directional control valve actuated by an operation device for control of flow rate and flow direction of the hydraulic fluid supplied to the hydraulic motor from the main pump. The hydraulic motor is provided with a mechanical brake device having a brake release cylinder adapted to release the rotary shaft of the motor from the braking by the mechanical brake device by supply of a hydraulic fluid to the brake release cylinder. The apparatus further has an auxiliary hydraulic pump and a control circuit connected to the auxiliary pump, brake release cylinder and reservoir for control of fluid communication therebetween. The control circuit includes a hydraulic fluid supply line for receiving a hydraulic fluid supplied from the auxiliary hydraulic pump, a first line connected between the hydraulic fluid supply line and the brake release cylinder, and a second line connected between the hydraulic fluid supply line and the reservoir.