US 4,850,812 AGranted

Integrated motor pump combination

AssigneesVersatron Corporation, F.P.I., Inc.

InventorAllan A. Voight

Life of this patent

Estimating the term…

Loading patent…

Abstract

An integrated motor pump unit for use as a hydraulic fluid pressure source at a remote location incorporates a pump rotor affixed in the center of a motor rotor. The motor/pump rotor assembly spins on a fixed shaft in a combination providing both radial journal and axial thrust bearings. The stationary shaft assembly incorporates a piston drive mechanism which is angled, relative to the shaft axis, so that reciprocal movement of the pistons is developed as they rotate about the axis. The fixed rotor shaft is axially adjustable to control the end clearance between the pistons and cam surfaces, and contains fluid flow galleries to the journal and thrust bearings. A magnetically permeable sleeve is mounted between the motor stator and rotor to seal the hydraulic fluid within the rotor space, thereby maintaining the stator windings and associated electronic circuitry in a dry environment. The combination functions as a servo pump under the control of an associated electronic motor controller unit and has the capability of providing variable flow directions and flow rates and pressures over a wide range for driving a hydraulic actuator or the like.

Claims19

Dependent claims

An integral motor pump combination comprising:

an axial-piston pump of the swash-plate type having a rotor containing a plurality of axially oriented cylinders and pistons which is mounted for rotation about a stationary shaft;
a brushless direct current motor having an electromagnetic stator mounted within a housing and a rotor including a plurality of permanent magnets spaced circumferentially about the longitudinal axis of said shaft, the magnets being mounted to the pump rotor to drive the pump rotor rotationally about said shaft;
means mounting the pump rotor, the motor rotor and the motor stator concentrically and generally axially coterminously of each other within said housing;
sealing means positioned between the motor rotor and the stator to prevent fluid driven by the pump from reaching the electrical circuitry associated with the electromagnetic stator;
an angled thrust plate rotatably mounted on said shaft for bearing against said pistons to develop reciprocal motion thereof during rotation of the pump rotor;
return means coupled to said pistons to cause said pistons to bear against said thrust plate during rotation of the pump rotor, said return means comprising an apertured return plate having means defining openings engaging respective necked-down portions of said pistons for urging the pistons into contact with said thrust plate throughout their rotation about the shaft;
and
a return bearing affixed to said shaft against rotation and having an angled bearing surface for supporting the return plate at a predetermined angle during rotation thereof about said shaft.

5 more elements

Dependencies are inferred from the claim text.