Internal gear pump

Patent metadata

Field	Value
Publication number	US-10060430-B2
Application number	US-201415104188-A
Country	US
Kind code	B2
Filing date	Dec 10, 2014
Priority date	Dec 13, 2013
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

An internal gear pump integrally provided with a plain bearing requiring fewer machining steps, allowing inexpensive manufacture, and offering a highly stable seizing property. The internal gear pump has a trochoid ( 4 ), in which an inner rotor ( 3 ) having a plurality of outer teeth is eccentrically and rotatably accommodated in an outer rotor ( 2 ) having a plurality of inner teeth, the outer teeth meshing with the inner teeth, and in which a suction-side chamber for suctioning liquid and a discharge-side chamber for discharging the liquid that has been suctioned into the suction-side chamber are formed between the inner teeth and outer teeth; a drive shaft ( 9 ) fixed to the inner rotor ( 3 ); a casing ( 5 ) in which is formed a recess ( 5 a ) for accommodating the trochoid ( 4 ); and a cover ( 6 ) for closing off the recess ( 5 a ) of the casing ( 5 ).

First claim

The invention claimed is:

1. An internal gear pump comprising a trochoid in which an inner rotor having a plurality of outer teeth is eccentrically and rotatably accommodated in an outer rotor having a plurality of inner teeth, the outer teeth meshing with the inner teeth, and in which a suction-side chamber for suctioning liquid and a discharge-side chamber for discharging the liquid suctioned into the suction-side chamber are formed between the inner teeth and the outer teeth;
said internal gear pump being characterized by comprising a drive shaft fixed to the inner rotor, a casing in which a recess for accommodating the trochoid is formed, and a cover for closing off the recess of the casing,
wherein one or both members are selected from the cover and the casing having a plain bearing part for rotatably supporting the drive shaft, and the plain bearing part being formed on said one or both members by injection-molding a thermoplastic resin composition,
wherein the plain bearing part has a radial bearing part and a thrust bearing part, said thrust bearing part being positioned on an inside-diameter side of the radial bearing part.

2. The internal gear pump according to claim 1 , characterized in that in the one or both members having the plain bearing part, an area where the plain bearing part is formed is a sintered metal body.

3. The internal gear pump according to claim 1 , characterized in that a drive-shaft thrust-supporting face of the thrust bearing part has lubrication grooves that communicate with a through-hole for the drive shaft in said drive-shaft thrust-supporting face.

4. The internal gear pump according to claim 1 , characterized in that the thermoplastic resin composition is made by blending carbon fibers and a polytetrafluoroethylene resin into a polyether ether ketone resin.

Assignees

• Ntn Toyo Bearing Co Ltd

Inventors

• Ishii Takuya
• Asada Hajime

Classifications

• F01C21/108

  with an axial surface, e.g. side plates · CPC title

• F16C2220/04

  by injection-moulding · CPC title

• F04C2240/50

  Bearings · CPC title

• F04C2240/20

  Rotors · CPC title

• F04C2230/60

  Assembly methods · CPC title