# US 2010/0166149 A1 · Mechanism and x-ray tube apparatus

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- Number: US 2010/0166149 A1
- Document ID: US20100166149A1
- Status: Published application
- Kind: A1
- Application number: 12/663,716
- Filed: 2008-06-12
- Published: 2010-07-01
- Earliest claimed: 2007-06-13
- Assignees: Hitachi Medical Corporation
- Inventors: Hidefumi Okamura
- Web page: https://patentgrep.com/patent/US20100166149A1

## CPC

- H01J 35/104: {Fluid bearings}
- F16C 33/1025: {with liquid, e.g. oil, as lubricant}
- F16C 33/103: {retained in or near the bearing}
- H01J 2235/106: Dynamic pressure bearings, e.g. helical groove type
- H01J 2235/1086: liquid metals
- Y10T 428/12993: Surface feature [e.g., rough, mirror]
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A mechanism to which a liquid-repellent structure hard to be exfoliated is applied. The tip of each of microprojections has a generally spherical surface. When a liquid metal (8) comes into contact with such a surface, the liquid metal (8) cannot enter the spaces among microprojections and is supported by the surfaces of the tips only with point contact. Therefore, the liquid metal (8) neither wets the surface of the base material nor spread over the surface. The liquid-repellent surface (11) has a structure such that the liquid metal (8) is supported by point contact of the many microprojections and repelled by the surface (11), and does not wet the surface (11).

## Claims

### Claim 1

A mechanism having an non-wetting and liquid-repellent surface structure which repels liquid metal for sealing the liquid metal, characterized in that multiple microprojections which point contact the liquid metal are provided on a base material surface so as to hold surface tension of the liquid metal.

### Claim 2

An X-ray tube device having an non-wetting and liquid-repellent structure which repels liquid metal to be applied to the boundary portion between a bearing gap and vacuum in a fluid slide bearing for rotary anode, characterized in that multi microprojections which point contact the liquid metal are provided on a base material surface so as to hold surface tension of the liquid metal.

### Claim 3 (depends on 2)

The X-ray tube device according to claim 2, characterized in that the liquid metal is formed by an alloy of gallium/indium/stannum.

### Claim 4 (depends on 3)

The X-ray tube device according to claim 3, characterized in that the tip of the microprojections are formed in a generally spherical shape.

### Claim 5 (depends on 3)

The X-ray tube device according to claim 3, characterized in that the width and height of the microprojections are in the range of 0.5˜3.0 μm.

### Claim 6 (depends on 3)

The X-ray tube device according to claim 3, characterized in that the basal side of the microprojections has greater content of chrome than the tip side thereof.

### Claim 7 (depends on 3)

The X-ray tube device according to claim 3, characterized in that multi microprojections are formed all over the base material surface.

### Claim 8

A method for manufacturing an non-wetting and liquid-repelling surface which repels liquid metal, characterized in performing heat treatment to iron alloy including chrome in hydrogen atmosphere including water vapor with the heat higher than the annealing temperature of the iron alloy so as to make the surface of iron alloy non-wetting and liquid-repellent.