# US 4,865,922 A · Plain bearing

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- Number: US 4,865,922 A
- Document ID: US4865922A
- Status: Granted
- Kind: A
- Application number: 07/077,113
- Filed: 1987-07-23
- Granted: 1989-09-12
- Earliest claimed: 1984-10-22
- Assignees: Aeplc
- Inventors: Glyndwr Davies
- Web page: https://patentgrep.com/patent/US4865922A

## CPC

- F16C 33/201: {Composition of the plastic}
- C08K 3/16: Halogen-containing compounds
- F16C 2208/32: Polytetrafluorethylene [PTFE] (F16C2208/58 takes precedence)
- Y10S 384/91: Powders
- Y10T 428/12049: Nonmetal component
- Y10T 428/1209: Plural particulate metal components
- Y10T 428/12139: Nonmetal particles in particulate component
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A cavitation erosion resistant plain bearing comprising a steel backing, a sintered bronze interlayer and a lining of PTFE filled with 1 to 50% by volume of an ionic fluoride of low aqueous solubility.

## Claims

### Claim 1

A plain bearing comprising a metal backing, a sinter layer on said metal backing and a bearing layer on said sinter layer, said bearing layer comprising a surface layer of polytetrafluoroethylene (PTFE) including 1 to 50% by volume of an ionic fluoride selected from the group consisting of CaF.sub.2, MgF.sub.2, SrF.sub.2 and mixtures thereof precipitated from an aqueous solution and having a solubility in water which is less than 0.5 g/cm.sup.3 at 18.degree. C., the ionic fluoride being in a finely divided form in the PTFE, the particle size being in the range from 0.01 to 10 microns.

### Claim 2 (depends on 1)

A bearing according to claim 1 wherein said backing is of steel.

### Claim 3 (depends on 2)

A bearing according to claim 2 wherein said sinter layer is sintered bronze.

### Claim 4 (depends on 1)

A bearing according to claim 1 wherein said fluoride is a fluoride selected from the group consisting of CaF.sub.2, MgF.sub.2 and SrF.sub.2.

### Claim 5 (depends on 4)

A bearing according to claim 4 wherein said surface layer further incorporates metallic lead.

### Claim 6 (depends on 1)

A plain bearing as described in claim 1 wherein the particle size of said fluoride is in the range of 0.1 to 1 micron.

### Claim 7 (depends on 1)

A plain bearing according to claim 1 wherein said fluoride is a combination of two or more of the fluorides selected from the group consisting of CaF.sub.2, MgF.sub.2 and SrF.sub.2.

### Claim 8 (depends on 1)

A plain bearing according to claim 1 wherein said fluoride is CaF.sub.2.

### Claim 9 (depends on 1)

A plain bearing according to claim 1 wherein said fluoride is CaF.sub.2 having a particle size in the range of 0.1 to 1 micron.

### Claim 10 (depends on 1)

A bearing according to claim 1 wherein the ionic fluoride is precipitated CaF.sub.2.

### Claim 11 (depends on 1)

A bearing according to claim 1 wherein the ionic fluoride is precipitated CaF.sub.2 and has a particle size in the range of 0.1 to 1 micron.

### Claim 12

A plain bearing comprising a metal backing, a sinter layer on said metal backing and a bearing layer on said sinter layer, said bearing layer comprising a surface layer of polytetrafluoroethylene containing from 1 to 50 volume percent of at least one ionic fluoride selected from the group consisting of CaF.sub.2, MgF.sub.2, SrF.sub.2 and mixtures thereof having a water solubility not greater than 0.05 grams per cubic centimeter at 18.degree. C. and a particle size in the range from 0.01 to 10 microns.

### Claim 13 (depends on 12)

A plain bearing according to claim 12 wherein said fluoride comprises CaF.sub.2.

### Claim 14 (depends on 13)

A plain bearing according to claim 13 wherein said fluoride has a particle size in the range from 0.1 to 1 micron.

### Claim 15 (depends on 12)

A plain bearing according to claim 12 wherein the particle size of said fluoride is in the range from 0.1 to 10 microns.

### Claim 16 (depends on 12)

A plain bearing according to claim 12 wherein the particle size of said fluoride is in the range from 0.1 to 1 micron.

### Claim 17 (depends on 12)

A plain bearing according to claim 12 wherein said fluoride is a combination of two or more of the fluorides selected from the group consisting of CaF.sub.2, MgF.sub.2, SrF.sub.2 and mixtures thereof.