Abstract: In hydraulic systems having rotating-stationary component interfaces, a bore pressure regulating mechanism is provided to interact with the hydraulic fluid in a control volume to maintain a hydraulic fluid pressure in a longitudinal shaft bore at or approximately equal to a supply pressure when a gear shaft rotates within the control volume. In one aspect, the bore pressure regulating mechanism minimizes vortex flow of the hydraulic fluid induced by the rotation of the gear shaft. In another aspect, the bore pressure regulating mechanism provides a direct feed of pressurized hydraulic fluid proximate an opening of the longitudinal shaft bore through an end surface of the gear shaft, and thereby minimizes the opportunity for the hydraulic fluid to be forced into vortex flow by the gear shaft in the area of the longitudinal shaft bore.

Abstract: In hydraulic systems having rotating-stationary component interfaces, a bore pressure regulating mechanism is provided to interact with the hydraulic fluid in a control volume to maintain a hydraulic fluid pressure in a longitudinal shaft bore at or approximately equal to a supply pressure when a gear shaft rotates within the control volume. In one aspect, the bore pressure regulating mechanism minimizes vortex flow of the hydraulic fluid induced by the rotation of the gear shaft. In another aspect, the bore pressure regulating mechanism provides a direct feed of pressurized hydraulic fluid proximate an opening of the longitudinal shaft bore through an end surface of the gear shaft, and thereby minimizes the opportunity for the hydraulic fluid to be forced into vortex flow by the gear shaft in the area of the longitudinal shaft bore.

Abstract: A fluid control valve system suitable for use in fluid systems. The valve system includes at least one check valve assembly that has a controllable bidirectional flow capability. The valve system and its check valve assembly can be installed in a fluid system that contains a pump/motor to enable the displacement output of the pump/motor to be controlled. The valve system further includes a pilot valve assembly and a device for controlling the check and pilot valve assemblies. The controlling device is adapted to control the pressure of at least one pilot fluid delivered to the pilot valve assembly, which enables the check valve assembly to selectively check flow of a working fluid flowing therethrough in either of two directions.

Abstract: A fluid control valve system suitable for use in fluid systems. The valve system includes at least one check valve assembly that has a controllable bidirectional flow capability. The valve system and its check valve assembly can be installed in a fluid system that contains a pump/motor to enable the displacement output of the pump/motor to be controlled. The valve system further includes a pilot valve assembly and a device for controlling the check and pilot valve assemblies. The controlling device is adapted to control the pressure of at least one pilot fluid delivered to the pilot valve assembly, which enables the check valve assembly to selectively check flow of a working fluid flowing therethrough in either of two directions.