# US 5,708,311 A · Integrated electric motor driven in line hydraulic pump

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- Number: US 5,708,311 A
- Document ID: US5708311A
- Status: Granted
- Kind: A
- Application number: 08/682,302
- Filed: 1996-07-17
- Granted: 1998-01-13
- Earliest claimed: 1996-07-17
- Assignees: Vickers, Incorporated
- Inventors: Leslie M. Claar; Robert C. Hodges
- Web page: https://patentgrep.com/patent/US5708311A

## CPC

- F04B 17/03: driven by electric motors
- F04B 1/20: having rotary cylinder block
- F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F)

## Abstract

An integrated electric motor-driven in-line hydraulic pump that includes a housing with an internal shaft, and a cylinder block mounted for rotation on the shaft. The rotor of an electric motor has an internally affixed bearing sleeve that is rotatably supported with respect to the shaft surrounding the cylinder block within the housing. Teeth on the sleeve engage splines on the cylinder block for rotatably coupling the rotor to the cylinder block. The stator of the electric motor is affixed within the housing surrounding the rotor. Pistons are operatively coupled to the cylinder block and engage a yoke plate for obtaining positive displacement pumping action upon energization of the motor. Fluid inlet and outlet ports feed hydraulic fluid through the housing to the cylinder block and pistons, and from the cylinder block to the outlet port.

## Claims

### Claim 1

An integrated electric motor-driven in-line hydraulic pump comprising:
a housing with a shaft carried within said housing,
a cylinder block mounted for rotation on said shaft and having splines extending from said cylinder block,
an electric motor rotor having a bearing sleeve internally affixed to said rotor with means on said sleeve for rotatably supporting said rotor with respect to said shaft surrounding said cylinder block and teeth on said sleeve engaging said splines for rotatably coupling said rotor to said cylinder block,
an electric motor stator affixed within said housing surrounding said rotor,
piston means operatively coupled to said cylinder block for obtaining positive displacement pumping action upon energization of said stator, and
fluid inlet and outlet means for feeding hydraulic fluid from said inlet means through said housing to said cylinder block and piston means, and thence to said outlet means.

### Claim 2 (depends on 1)

The pump set forth in claim 1 wherein said bearing sleeve includes a hollow body of uniform outer diameter received by press fit within said electric motor rotor.

### Claim 3 (depends on 2)

The pump set forth in claim 2 wherein said bearing sleeve further includes a radially outwardly projecting end flange that abuts an axial end of said rotor.

### Claim 4 (depends on 2)

The pump set forth in claim 2 wherein said bearing sleeve further includes means extending radially inwardly from said body to a cylindrical bearing surface within said sleeve, said pump further comprising bearing means rotatably supporting said bearing surface with respect to said stationary shaft.

### Claim 5 (depends on 4)

The pump set forth in claim 4 wherein said bearing surface is disposed mid-way of said sleeve axially of said shaft.

### Claim 6 (depends on 2)

The pump set forth in claim 2 wherein said splines are disposed on a radially outwardly facing surface of said cylinder block, and said teeth extend radially inwardly from said sleeve.