Parker-Hannifin Corporation

Dyminski, Daniel

Daniel Dyminski

Matthew Herman Simon

Bruce D Larkin

Brewce Larkin

A variable displacement hydraulic pump including a control actuator configured to interact with a movable displacement control member to control the displacement of the pump; and a displacement control valve assembly configured to provide mechanical feedback control of positioning of the control actuator and thereby the displacement control member. The displacement control valve assembly includes a control valve member that is movable within a fluid flow path of the control valve assembly to control a flow of fluid to or from the control actuator. The control valve assembly includes a first valve part, a second valve part, and a biasing member configured to selectively position respective one or more portions of the first and second valve parts relative to each other to open or close a vent flow passage in response to an operating state of the pump. When in a normal operating state of the pump, the biasing member is configured to position the first and second valve parts relative to each other such that the vent flow passage is closed, and the control valve member moves in the fluid flow path to control the flow of fluid to or from the control actuator. When in a failsafe state of the pump, the biasing member is configured to position the first and second valve parts relative to each other such that the vent flow passage is opened, thereby enabling fluid from the control actuator to escape via the vent flow passage.

Displacement control for hydraulic pump

An inlet baffle chamber () is provided in the port cover () of a piston pump. The inlet baffle chamber () fluidly connects a compressed piston chamber to an adjacent lower pressure piston chamber while the lower pressure piston chamber is in the suction cycle and separately receiving fluid from an inlet manifold () of the port cover (). Instead of de-compressing high pressure fluid directly to pump's inlet () as in prior art pumps, the inlet baffle chamber () directs fluid to the next piston that is already in the suction cycle.

Hydraulic pump with inlet baffle

A pump barrel () for use in a hydrostatic pump assembly includes a barrel body () defining a plurality of piston bores () that receive a plurality of pistons moveable within the bores, and a porting face () that defines a plurality of ports () in fluid communication with the piston bores and providing fluid flow paths into and out from the barrel body. Each port () has a leading edge surface and a trailing edge surface relative to a direction of rotation of the pump barrel, said leading and trailing edge surfaces being oriented in a first direction (along line-) at non-right angles relative to the porting face (). Each port () has an inner edge surface () and an outer edge surface () relative to a radial direction of the pump barrel, said inner and outer edge surfaces () being oriented in a second direction (along line-) comprising a tilt angle () relative to the porting face () that is different from the angles in the first direction. A hydrostatic pump assembly incorporating such a pump barrel () is also disclosed.

Hydrostatic pump barrel with sloped kidney ports

A piston-slipper assembly and method for assembling a piston-slipper assembly for use in a hydraulic apparatus such as a piston motor or piston pump. The assembly contains a piston and a slipper, and at least one of the piston or the slipper includes a ball and the other includes a socket. The ball is retained in the socket without crimping, swaging or bending of the socket.

Growing community of inventors

Portage, MI, United States of America

Daniel Dyminski