US 4,477,231 AGranted

Variable displacement vane type pump

OwnerJoseph E. Swiftinventor

Life of this patent

Estimating the term…

Abstract

A variable displacement vane type hydraulic pump of simple construction automatically varies its output flow rate, between a maximum value and zero, in response to changes in the output pressure. The pump is characterized by a laterally shifting flow modulating member located in a central recess of a vane carrying rotor and whose lateral position is dictated by the pressure existing at the outlet port. The pump can run continuously at a no-flow condition without overheating or stalling and its rotor direction may be reversed by merely reversing the functions of its two ports.

Claims17

Dependent claims

A variable displacement vane type pump comprising:

a stationary structure,
a rotor supported by said stationary structure for rotation relative thereto about a horizontal rotor axis, said rotor having a cylindrical radially outwardly facing outer surface concentric with said axis and also having a right-hand end surface,
said rotor having a recess extending leftwardly from said rotor right-hand end surface which recess is defined in part by a radially inwardly facing surface generally symmetrical about said axis,
a flow modulating member having a cam portion with right and left-hand ends located in said rotor recess, said cam portion having a radially outwardly facing cylindrical cam surface, concentric about a corresponding cam portion axis, of such diameter that said cam portion fits radially loosely in said rotor recess,
means supporting said flow modulating member from said stationary structure so that said cam portion axis is parallel to said rotor axis and so that said modulating member is laterally movable relative to said stationary structure, to vary the spacing between said rotor axis and said cam portion axis, between a position at which said cam portion has a maximum eccentricity relative to said rotor axis and a position of lesser eccentricity,
means biasing said modulating member relative to said stationary structure toward said position of maximum eccentricity,
means at both said right and left-hand ends of said cam portion closing the radial space between said radially inwardly facing recess surface and said radially outwardly facing cam surface to define a fluid confining chamber between said recess surface and said cam surface,
means providing an inlet port and an outlet port in said stationary structure both communicating with said fluid confining chamber, said inlet and outlet ports being located respectively on opposite sides of the plane of movement of said cam portion axis,
a plurality of vanes carried by said rotor for radial sliding movement relative to said rotor and engageable at their inner ends with said cam surface, and
means biasing said vanes radially inwardly relative to said rotor into engagment with said cam surface,
said vanes extending axially across the full extent of said fluid confining chamber so as to divide said fluid confining chamber into a plurality of fluid confining sub-chambers which move with said rotor and which sub-chambers are increasing in volume as they pass said inlet port and are decreasing in volume as they pass said outlet port.

8 more elements

Dependencies are inferred from the claim text.

patentgrep

Loading patent…

Abstract

A variable displacement vane type pump comprising:

a stationary structure,
a rotor supported by said stationary structure for rotation relative thereto about a horizontal rotor axis, said rotor having a cylindrical radially outwardly facing outer surface concentric with said axis and also having a right-hand end surface,
said rotor having a recess extending leftwardly from said rotor right-hand end surface which recess is defined in part by a radially inwardly facing surface generally symmetrical about said axis,
a flow modulating member having a cam portion with right and left-hand ends located in said rotor recess, said cam portion having a radially outwardly facing cylindrical cam surface, concentric about a corresponding cam portion axis, of such diameter that said cam portion fits radially loosely in said rotor recess,
means supporting said flow modulating member from said stationary structure so that said cam portion axis is parallel to said rotor axis and so that said modulating member is laterally movable relative to said stationary structure, to vary the spacing between said rotor axis and said cam portion axis, between a position at which said cam portion has a maximum eccentricity relative to said rotor axis and a position of lesser eccentricity,
means biasing said modulating member relative to said stationary structure toward said position of maximum eccentricity,
means at both said right and left-hand ends of said cam portion closing the radial space between said radially inwardly facing recess surface and said radially outwardly facing cam surface to define a fluid confining chamber between said recess surface and said cam surface,
means providing an inlet port and an outlet port in said stationary structure both communicating with said fluid confining chamber, said inlet and outlet ports being located respectively on opposite sides of the plane of movement of said cam portion axis,
a plurality of vanes carried by said rotor for radial sliding movement relative to said rotor and engageable at their inner ends with said cam surface, and
means biasing said vanes radially inwardly relative to said rotor into engagment with said cam surface,
said vanes extending axially across the full extent of said fluid confining chamber so as to divide said fluid confining chamber into a plurality of fluid confining sub-chambers which move with said rotor and which sub-chambers are increasing in volume as they pass said inlet port and are decreasing in volume as they pass said outlet port.

8 more elements