# US 4,395,207 A · Gear pump or motor with bearing passage for shaft lubrication

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- Number: US 4,395,207 A
- Document ID: US4395207A
- Status: Granted
- Kind: A
- Application number: 06/197,471
- Filed: 1980-10-16
- Granted: 1983-07-26
- Earliest claimed: 1979-10-22
- Assignees: Valmet Corporation
- Inventors: Erkki Manttari; Matti Korpinen
- Web page: https://patentgrep.com/patent/US4395207A

## CPC

- F04C 2/086: {Carter}
- F04C 15/0088: {Lubrication (of machines or engines in general F01M)}
- F04C 2240/56: Bearing bushings or details thereof
- F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS

## Abstract

Gear pump and motor apparatus adapted to operate both as a pump and as a motor include two meshing gears whose shafts are supported in a housing chamber by respective bearing sleeves whose end faces sealingly engage the end faces of the respective gears. An oil supply passage is formed in each of the bearing sleeves in a region diametrically opposed to flat surface portions formed on the outer peripheral surface of the bearing sleeves and near a central plane which passes through the axes of cylindrical chamber portions in which the gears are situated. Oil leaking from the pump/motor chamber is directed into spaces defined between the peripheral surfaces of the bearing sleeves and the respective chamber portions through the oil supply passages into the bearing sleeve openings to lubricate the gear shafts which are received therein. The ratio of the length to the diameter of each of the oil supply passages is less than or equal to about 10.

## Claims

### Claim 1

Gear pump and motor apparatus adapted to operate alternatively either as a pump or as a motor, comprising: a housing having a chamber defined therein, said chamber including a pair of superimposed substantially cylindrical portions defined by respective substantially cylindrical inwardly facing surfaces, said chamber portions intercommunicating with each other; a pair of parallely extending toothed gears situated in said housing chamber in meshing engagement with each other, each of said gears having an axial shaft fixed to and extending from at least one of its ends; a pair of bearing sleeves, each bearing sleeve being mounted in a respective chamber portion of said housing chamber and including a body having an inner face surface adapted to normally sealingly engage the end face of a respective gear, an opposed outer face surface, a substantially cylindrical outer peripheral surface having a diameter smaller than the diameter of said inwardly facing cylindrical surface of a respective cylindrical chamber portion and defining a space between it and said inwardly facing surface of the respective cylindrical chamber portion of said housing chamber, and a central opening which receives and supports a shaft of a respective one of said gears for mounting the latter in a respective portion of said housing chamber, and an oil supply bore formed through each bearing sleeve substantially in the plane which passes through the axes of said chamber portions, each bore opening at one end into the space defined by the outer peripheral surface of a respective bearing sleeve and the inwardly facing surface of a respective chamber portion and opening at its other end into the central opening of said bearing sleeve, and wherein the ratio of the length to the diameter of each of said oil supply bores being less than or equal to about 10, whereby oil is directed from said spaces defined between the peripheral surfaces of the bearing sleeves and the inwardly facing surfaces of the respective chamber portions through said bores into said bearing sleeve openings to lubricate the gear shaft received therein.

### Claim 2 (depends on 1)

The combination of claim 1 wherein in a cross section transverse to the axis of said bearing sleeves, each of said oil supply bores extends substantially radially with respect to a respective bearing sleeve.

### Claim 3 (depends on 1)

The combination of claim 1 wherein said outer peripheral surfaces of said bearing sleeve bodies are formed with respective flat portions which engage each other in the region where said cylindrical chamber portions intercommunicate and wherein said oil supply bores formed in said bearing sleeves are formed in a region which is diametrically opposed to said flat surface portions.

### Claim 4 (depends on 1)

The combination of claim 1 wherein in a longitudinal cross section of said apparatus relative to the axes of said sleeve bearings, an outer end of each oil supply bores opens onto a substantially axially central region of the peripheral surface of a respective bearing while an inner end of said bores opens into the central opening of said bearing sleeve at a region closer to said end face of a respective gear than to said outer end face of said bearing sleeve.

### Claim 5 (depends on 4)

The combination of claim 4 wherein in a cross section transverse to the axes of said bearing sleeves, each of said oil supply bores extends substantially radially with respect to a respective bearing sleeve.