FLUID PUMP FOR A LINEAR ACTUATOR

摘要

A fluid pump for a linear actuator is provided. The pump causes a rod in the actuator to extend or retract by controlling the flow of fluid to and from portions of a fluid chamber on either side of a piston disposed within the fluid chamber and supporting the rod. The pump includes a valve structure that enables the pump to redistribute fluid obtained from one portion of the fluid chamber on one side of the piston to the other portion of the fluid chamber on the other side of the piston without first returning the fluid to a fluid reservoir thereby increasing the efficiency of the pump.

主权项

1. A fluid pump for a linear actuator, comprising:
a housing defining an inlet port configured for fluid communication with a fluid reservoir and first and second outlet ports configured for fluid communication with first and second portions of a fluid chamber formed on opposite sides of a piston disposed within said fluid chamber; a driven pump element disposed within said housing; a first shuttle disposed on a first axial side of said driven pump element and movable between a first fluid flow position permitting fluid flow between said inlet port and said driven pump element along a first fluid flow path and a second fluid flow position permitting fluid flow between said inlet port and said driven pump element along a second fluid flow path; a first check valve disposed on a second axial side of said driven pump element and movable between a closed position and an open position permitting fluid flow between said driven pump element and said first outlet port; a second check valve disposed on said second axial side of said driven pump element and movable between a closed position and an open position permitting fluid flow between said driven pump element and said second outlet port; and, a second shuttle disposed on said second axial side of said driven pump element and movable between a first position in which said second shuttle causes said first check valve to assume said open position and a second position in which said second shuttle causes said second check valve to assume said open position; wherein rotation of said driven pump element in a first rotational direction results in movement of said first shuttle to said first fluid flow position, movement of said first check valve to said open position and movement of said second shuttle to said second position and rotation of said driven pump element in a second rotational direction opposite said first rotational direction results in movement of said first shuttle to said second fluid flow position, movement of said second valve to said open position and movement of said second shuttle to said first position.