초록 ▼

A hydraulic motor control system comprises a speed control loop and a pressure control loop which provide closed loop control of a variable displacement chamber space and the mechanical advantage coupling thereof to the motor output shaft. The speed control loop is effective in the speed control mod

A hydraulic motor control system comprises a speed control loop and a pressure control loop which provide closed loop control of a variable displacement chamber space and the mechanical advantage coupling thereof to the motor output shaft. The speed control loop is effective in the speed control mode of operation to maintain a set speed within a given load range. In response to load increases beyond said range, the pressure control loop pre-empts the speed control loop so that the control operates in a constant horsepower mode.

대표청구항 ▼

A system for controlling a hydraulic fluid powered rotary output shaft comprising a chamber space for hydraulic power fluid having variable displacement, an operative coupling from said chamber space effective to rotate said output shaft by the hydraulic power fluid in said chamber space, means to a

A system for controlling a hydraulic fluid powered rotary output shaft comprising a chamber space for hydraulic power fluid having variable displacement, an operative coupling from said chamber space effective to rotate said output shaft by the hydraulic power fluid in said chamber space, means to adjust the displacement of said variable displacement chamber space, means providing a speed representative signal representative of the rotational speed of said output shaft, means providing another signal representing another parameter indicative of load on said output shaft, means providing a speed control signal representative of a predetermined rotational speed for said output shaft, means providing a further control signal representing a predetermined value for said another parameter, means comparing said speed representative signal against said speed control signal, means comparing said another signal against said further control signal, and priority according means comprising means according priority to the comparison of said speed representative signal and speed control signal in closed loop control of the adjustment of the displacement of said chamber space when said further control signal and said another control signal bear one predetermined relationship with each other and means according priority to the comparison of said another control signal and said further control signal in closed loop control of the adjustment of the displacement of said chamber space when said another signal and said further control signal bear another predetermined relationship with each other.