Electrohydraulic system and apparatus with bidirectional electric-motor/hydraulic-pump unit

An electrohydraulic control system that comprises:

• bidirectional electric motor means responsive to application of electrical power for rotation in either of two directions,
• hydraulic pump means coupled to said electric motor means and having ports for supplying hydraulic fluid in either of two flow directions as a function of direction of rotation of said electric motor means,
• hydraulic actuator means coupled to said ports of said hydraulic pump means for receiving fluid in either of two flow directions and performing work as a function thereof, and
• electronic control means for applying electrical power to said electric motor means so as to obtain a desired work at said actuator means,
• said bidirectional electric motor means having a motor output shaft, and said hydraulic pump means comprising bidirectional hydraulic pump means coupled to said shaft,
• said bidirectional motor means having one or more endplates into which said motor output shaft extends, said hydraulic pump means being mounted on said one or more endplates to form a unitary assembly with said motor means,
• said bidirectional electric motor means comprising a fluid-cooled motor having a housing with ports for feeding fluid through said housing, and said system further including means for routing hydraulic fluid through said motor housing between said pump means and said actuator means.

An electrohydraulic control system that comprises:

• bidirectional electric motor means responsive to application of electrical power for rotation in either of two directions,
• hydraulic pump means coupled to said electric motor means and having ports for supplying hydraulic fluid in either of two flow directions as a function of direction of rotation of said electric motor means,
• hydraulic actuator means coupled to said ports of said hydraulic pump means for receiving fluid in either of two flow directions and performing work as a function thereof, and
• electronic control means for applying electrical power to said electric motor means so as to obtain a desired work at said actuator means,
• said bidirectional electric motor means having a motor output shaft, and said hydraulic pump means comprising bidirectional hydraulic pump means coupled to said shaft,
• said bidirectional hydraulic pump means comprising a pair of unidirectional hydraulic pumps and a pair of directional couplers respectively connecting said pumps to said motor output shaft such that said pumps are alternately coupled to said shaft as a function of direction of rotation of said shaft, each of said unidirectional pumps having an inlet port and an outlet port, and said system further comprising valve means responsive to direction and/or pressure of hydraulic fluid flow for controlling fluid flow between said actuator means and said pump ports.

An electrohydraulic control system that comprises:

• bidirectional electric motor means responsive to application of electrical power for rotation in either of two directions,
• hydraulic pump means coupled to said electric motor means and having ports for supplying hydraulic fluid in either of two flow directions as a function of direction of rotation of said electric motor means,
• hydraulic actuator means coupled to said ports of said hydraulic pump means for receiving fluid in either of two flow directions and performing work as a function thereof,
• electronic control means for applying electrical power to said electric motor means so as to obtain a desired work at said actuator means, and
• valve means operatively coupled to said pump means and said actuator means for controlling flow of hydraulic fluid between said pump means and said actuator means, said valve means comprising pilot-operated passive hydraulic check valves responsive to direction and/or pressure of hydraulic fluid flow to control vent ports of associated pressure relief valves and thereby control fluid flow between said motor means and said actuator means.