# US 5,701,668 A · Method of making a refrigeration compressor thrust bearing assembly

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- Number: US 5,701,668 A
- Document ID: US5701668A
- Status: Granted
- Kind: A
- Application number: 08/678,497
- Filed: 1996-07-09
- Granted: 1997-12-30
- Earliest claimed: 1995-05-23
- Assignees: Tecumseh Products Company
- Inventors: Nelik I. Dreiman; Tara C. Kandpal
- Web page: https://patentgrep.com/patent/US5701668A

## CPC

- F04B 39/0094: {crankshaft}
- F16C 33/04: Brasses; Bushes; Linings
- Y10S 384/909: Plastic
- Y10S 417/902: Hermetically sealed motor pump unit
- Y10T 29/49236: Fluid pump or compressor making
- Y10T 29/49826: Assembling or joining
- 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)
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A refrigeration compressor includes a polyamide annular thrust bearing pressfit within a countersunk recess in the rotor aperture and having radially extending lubricating oil grooves on a lower surface thereof. A vertical crankshaft being concentrically disposed within and secured to the rotor at one end and being journalled for rotation within a vertical bore defined by a bearing hub formed in a frame. The bearing hub supports the rotor and crankshaft combination. The bearing hub includes an upper end face which is machine ground and polished to a smooth surface and which is in contact with the smooth lower surface of the thrust bearing thereby forming a frictional pair. A reduction in mechanical friction and power consumption is realized by use of the polyamide thrust bearing and the smooth polishing of the hub upper end face thereby increasing the overall efficiency associated with the refrigeration compressor.

## Claims

### Claim 1

A method of manufacturing a motor-compressor unit for use in a refrigeration compressor having a motor including a stator and a rotor, a crankshaft connected to the rotor, and a frame having a bearing hub receiving and supporting the crankshaft and rotor assembly, the manufacturing method including the steps of:
forming an annular thrust bearing from a fluorocarbon-based resin and providing at least one oil distributing groove on a lower surface of the thrust bearing;
press fitting the thrust bearing within a recess formed in the rotor, whereby the thrust bearing lower surface faces the bearing hub and the thrust bearing is fixed relative to the rotor;
processing an upper surface of the bearing hub to a finish of at least 63 microinches;
disposing the crankshaft within the rotor recess and connecting the crankshaft to the rotor so as to prohibit the movement of the crankshaft relative to the rotor; and
disposing the rotor and crankshaft assembly within the stator with an end of the crankshaft extending axially away from the rotor and being rotatably received in a bore formed in the bearing hub, whereby the lower surface of the thrust bearing engages and is supported by the upper surface of the bearing hub.

### Claim 2 (depends on 1)

The method of claim 1 wherein the processing step comprises polishing the upper surface of the bearing hub to a smoothness of at least 20 microinches.

### Claim 3 (depends on 1)

The method of claim 1 wherein the processing step comprises grinding the upper surface of the bearing hub to a smoothness of at least 63 microinches.

### Claim 4 (depends on 1)

The method of claim 1 wherein the forming step comprises providing at least three oil distributing grooves on the lower surface of the bearing.

### Claim 5 (depends on 4)

The method of claim 4 wherein the forming step comprises providing at least three oil distributing grooves on the lower surface of the bearing spaced evenly about the circumference of the thrust bearing.

### Claim 6 (depends on 1)

The method of claim 1 wherein the step of discussing the crankshaft in the rotor comprises connecting the crankshaft to the rotor by an interference fit.

### Claim 7 (depends on 1)

The method of claim 1 wherein the forming step comprises forming the annular thrust bearing from one of a group comprised of polyamides and aramids.

### Claim 8 (depends on 1)

The method of claim 1 wherein the forming step comprises making the at least one oil distributing groove semi-circular in cross-section.