# US 9,518,581 B2 · Vane pump including shaft fitting concave not to be penetrated

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- Number: US 9,518,581 B2
- Document ID: US9518581B2
- Status: Granted
- Kind: B2
- Application number: 14/409,402
- Filed: 2012-09-28
- Published: 2015-11-19
- Granted: 2016-12-13
- Earliest claimed: 2012-09-28
- Assignees: Mitsubishi Electric Corporation
- Applicants: Satoshi Nakagawa
- Inventors: Satoshi Nakagawa
- Web page: https://patentgrep.com/patent/US9518581B2

## CPC

- F04C 18/3441: {the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation}
- F01C 21/0809: {Construction of vanes or vane holders}
- F01C 21/108: {with an axial surface, e.g. side plates}
- F04C 2/344: with vanes reciprocating with respect to the inner member
- F04C 2/3441: {the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation}
- F04C 15/0076: {Fixing rotors on shafts, e.g. by clamping together hub and shaft}
- F04C 18/344: with vanes reciprocating with respect to the inner member
- F04C 27/005: {Axial sealings for working fluid}
- F04C 29/0078: {Fixing rotors on shafts, e.g. by clamping together hub and shaft}
- F04C 2240/20: Rotors
- F04C 2240/60: Shafts
- F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F01C: ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES (internal-combustion aspects F02B53/00, F02B55/00)

## Abstract

A shaft is fitted in a shaft fitting concave part to provide a structure such that no shaft penetrates through a rotor, so that an inner space (shaft fitting concave part, and hollow parts) and an outer space (pump chamber) of the rotor are made independent. The inner space of the rotor is communicated with outside to be at a low pressure, and the outer space is at a high pressure due to gas compression, and an upper surface of the rotor slides on an inner wall surface of a rotor housing part with pressed against this inner wall surface by a pressure difference.

## Claims

### Claim 1

A vane pump comprising:
a first housing having a rotor housing that houses a rotor, an intake port, and a shaft through-hole through which a motor shaft is penetrated to the rotor housing;
a second housing having a discharge port that allow the rotor housing to communicate with outside;
a cylindrical rotor that is housed in the rotor housing eccentrically to a center of the rotor housing and that rotates integrally with the motor shaft; and
vanes that are installed in the rotor, movable outward in a radial direction by receiving rotation force of the rotor, and rotates in sliding contact with an inner peripheral surface of the rotor housing,
wherein the rotor has a shaft fitting concave in which an end portion of the motor shaft that penetrates through the shaft through-hole is fitted, and the shaft fitting concave is formed on a surface of the rotor that faces the motor shaft, not permitting penetration to the opposite side of the surface of the rotor that faces the motor shaft.

### Claim 2 (depends on 1)

The vane pump according to claim 1, wherein an opening area of the discharge port is smaller than that of the intake port.

### Claim 3 (depends on 1)

The vane pump according to claim 1, wherein one or both of a surface on which the shaft fitting concave of the rotor is formed and a surface of the first housing that faces the surface on which the shaft fitting concave of the rotor is formed are smooth surfaces.

### Claim 4 (depends on 1)

The vane pump according to claim 1, wherein the second housing is communicated with the discharge port and also has a groove at a position that faces the rotor.

### Claim 5 (depends on 1)

The vane pump according to claim 1, wherein a concave-convex shape is formed on one or both of a surface opposite to the surface on which the shaft fitting concave of the rotor is formed, and a surface of the second housing that faces the opposite surface.

### Claim 6 (depends on 1)

The vane pump according to claim 1, wherein a serrated concave-convex shape is formed on one or both of a surface opposite to the surface on which the shaft fitting concave of the rotor is formed, and a surface of the second housing that faces the opposite surface.

### Claim 7 (depends on 1)

The vane pump according to claim 1, wherein one of or both of a surface opposite to the surface on which the shaft fitting concave of the rotor is formed and a surface of the second housing that faces the opposite surface are rough surfaces.