Gear pump

Patent metadata

Field	Value
Publication number	US-9506466-B2
Application number	US-201414339603-A
Country	US
Kind code	B2
Filing date	Jul 24, 2014
Priority date	Jul 24, 2013
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

In a gear pump, an outer rotor and an inner rotor are disposed in a rotor installation chamber defined by a pump body and a pump cover. A suction port groove and a discharge port groove are formed in at least one of the pump body and the pump cover. A narrowing portion is formed at a portion of a radially outer side wall portion of the suction port groove, the portion being close to a terminal end wall portion of the suction port groove. The narrowing portion narrows the groove width in the radial direction. A pressurizing region that pressurizes oil in the gear chamber is formed between the narrowing portion and the terminal end wall portion.

First claim

What is claimed is:

1. A gear pump comprising:
a pump body;
a pump cover;
an outer rotor having a plurality of internal teeth;
an inner rotor having external teeth meshed with the internal teeth and able to be driven to be rotated;
a rotor installation chamber defined by the pump body and the pump cover, wherein the outer rotor and the inner rotor are disposed in the rotor installation chamber;
gear chambers defined between the internal teeth of the outer rotor and the external teeth of the inner rotor;
a suction port groove that forms a suction port, and a discharge port groove that forms a discharge port, provided in at least one of the pump body and the pump cover, wherein the suction port groove has a radially outer side wall; and
means provided on the radially outer side wall of the suction port groove to induce pressurization by centrifugal force of oil in the gear chamber that is defined between the internal tooth and the external tooth and that is located at a position on the suction port groove side and closest to a terminal end wall portion of the suction port groove.

2. The gear pump according to claim 1 , further comprising means for restraining the pressurized oil in the gear chamber located closest to the terminal end wall portion of the suction port groove from flowing back into the suction port groove.

3. A gear pump comprising:
a pump body;
a pump cover;
an outer rotor having a plurality of internal teeth;
an inner rotor having external teeth meshed with the internal teeth and able to be driven to be rotated;
a rotor installation chamber defined by the pump body and the pump cover, wherein the outer rotor and the inner rotor are disposed in the rotor installation chamber;
gear chambers defined between the internal teeth of the outer rotor and the external teeth of the inner rotor;
a suction port groove that forms a suction port, and a discharge port groove that forms a discharge port, provided in at least one of the pump body and the pump cover, wherein the suction port groove has a radially outer side wall and a radially inner side wall;
a narrowing portion of the suction port groove, the narrowing portion being provided at a portion of the radially outer side wall portion of the suction port groove, the narrowing portion being located close to a terminal end wall portion of the suction port groove, the narrowing portion bulging toward the radially inner side wall of the suction port groove to narrow a groove width of the suction port groove in a radial direction; and
a pressurizing region provided between the narrowing portion and the terminal end wall portion, the pressurizing region pressurizing oil in the gear chamber that is defined between the internal tooth and the external tooth and that is located at a position on the suction port groove side and closest to the terminal end wall portion.

4. The gear pump according to claim 3 , wherein a bulging position of the narrowing portion with respect to the radially outer side wall portion of the suction port groove is set such that the pressurizing region is formed in a range from the terminal end wall portion of the suction port groove to a position that is apart from the terminal end wall portion by a distance corresponding to one pitch of the internal teeth.

5. The gear pump according to claim 4 , wherein the suction port groove has a portion with a groove depth smaller than that of the other portion of the suction port, the portion being located in the pressurizing region to restrain the pressurized oil in the gear chamber located closest to the terminal end wall portion of the suction port groove from flowing back into the suction port groove.

6. The gear pump according to claim 5 , wherein the suction port groove is formed such that the groove width in the radial direction gradually increases from the narrowing portion toward the terminal end wall portion.

7. The gear pump according to claim 4 , wherein the suction port groove is formed such that the groove width in the radial direction gradually increases from the narrowing portion toward the terminal end wall portion.

8. The gear pump according to claim 3 , wherein the suction port groove has a portion with a groove depth smaller than that of the other portion of the suction port, the portion being located in the pressurizing region to restrain the pressurized oil in the gear chamber located closest to the terminal end wall portion of the suction port groove from flowing back into the suction port groove.

9. The gear pump according to claim 8 , wherein the suction port groove is formed such that the groove width in the radial direction gradually increases from the narrowing portion toward the terminal end wall portion.

10. The gear pump according to claim 3 , wherein the suction port groove is formed such that the groove width in the radial direction gradually increases from the narrowing portion toward the terminal end wall portion.

Assignees

• Jtekt Corp

Inventors

• Ebihara Tsuyoshi
• Morita Teppei
• Udo Katsuhisa

Classifications

• F04C2/102

  the two members rotating simultaneously around their respective axes · CPC title

• F04C2/086

  Carter · CPC title

• F04C2250/101

  of the inlet · CPC title

• F04C2/10 Primary

  of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member · CPC title

• F04C15/0026

  Elements specially adapted for sealing of the lateral faces of intermeshing-engagement type machines or pumps, e.g. gear machines or pumps · CPC title