초록 ▼

A hydraulic power system having a variable displacement hydraulic pump, a hydraulic motor driven by the hydraulic pump for actuating a load, the pump and motor being connected to constitute a closed hydraulic circuit, hydraulic servo for controlling the displacement volume of the pump, and motor sto

A hydraulic power system having a variable displacement hydraulic pump, a hydraulic motor driven by the hydraulic pump for actuating a load, the pump and motor being connected to constitute a closed hydraulic circuit, hydraulic servo for controlling the displacement volume of the pump, and motor stopping device including a brake arrangement adapted to release the motor from a braked condition when a control pressure from a hydraulic fluid source is received. The system includes a control valve responsive to a main line pressure in the closed hydraulic circuit for controlling a hydraulic fluid supply to the servo to prevent the main line pressure from substantially exceeding a predetermined level, first pressure transmission control interlocked with an input of the servo for transmitting the control pressure to the brake arrangement when the input is actuated, and a second pressure transmission control responsive to the pressure of a hydraulic fluid supply to the servo on the output side of the control valve for transmitting the control pressure to the brake arrangement when the supply pressure is substantially lower than a normal supply pressure of the hydraulic fluid source.

대표청구항 ▼

A hydraulic power system comprising a variable displacement hydraulic pump, a hydraulic motor driven by said hydraulic pump for actuating a load, said pump and motor being connected to constitute a closed hydraulic circuit, hydraulic servo means for controlling the displacement volume of said pump,

A hydraulic power system comprising a variable displacement hydraulic pump, a hydraulic motor driven by said hydraulic pump for actuating a load, said pump and motor being connected to constitute a closed hydraulic circuit, hydraulic servo means for controlling the displacement volume of said pump, and motor stopping means including brake means adapted to release the motor from a braked condition when a control pressure from a hydraulic fluid source is received, wherein the hydraulic power system comprises: a control valve responsive to a main line pressure in said closed hydraulic circuit for controlling a hydraulic fluid supply to said servo means to prevent said main line pressure from substantially exceeding a predetermined level; first pressure transmission control means interlocked with input means of said servo means for transmitting said control pressure to said brake means when said input means is actuated; and second pressure transmission control means responsive to the pressure of a hydraulic fluid supply to said servo means on the output side of the control valve for transmitting said control pressure to said brake means when said supply pressure is substantially lower than a normal supply pressure of the hydraulic fluid source.