Fluid pump

Patent metadata

Field	Value
Publication number	US-2016298625-A1
Application number	US-201615096657-A
Country	US
Kind code	A1
Filing date	Apr 12, 2016
Priority date	Apr 13, 2015
Publication date	Oct 13, 2016
Grant date	—

Abstract

A pump housing receives an outer rotor and an inner rotor. A joint member couples between a rotatable shaft and the inner rotor to transmit a rotational torque from the rotatable shaft to the inner rotor. A radial bearing is shaped into a cylindrical tubular form. A cylindrical inner peripheral surface of the radial bearing rotatably and slidably supports the rotatable shaft. A cylindrical outer peripheral surface of the radial bearing rotatably and slidably supports an inner peripheral surface of the inner rotor. A lubrication groove is formed in the cylindrical outer peripheral surface of the radial bearing and accumulates fluid, which is present in an inside of the pump housing.

First claim

What is claimed is:

1 . A fluid pump comprising:
an inner rotor that is shaped into a cylindrical tubular form and has a plurality of external teeth; an outer rotor that has a plurality of internal teeth for meshing with the plurality of external teeth; a pump housing that receives the outer rotor and the inner rotor and forms a plurality of pump chambers between the plurality of internal teeth and the plurality of external teeth, wherein each of the plurality of pump chambers draws and compresses fluid by changing a volume of the pump chamber; a rotatable shaft that is placed to extend over both of:
a high pressure passage, which conducts the fluid discharged from each corresponding one of the plurality of pump chambers; and
an inside of the pump housing;
a joint member that couples between the inner rotor and the rotatable shaft to transmit a rotational torque of the rotatable shaft to the inner rotor; and a radial bearing that is shaped into a cylindrical tubular form, wherein the radial bearing rotatably and slidably supports the rotatable shaft through a cylindrical inner peripheral surface of the radial bearing and rotatably and slidably supports an inner peripheral surface of the inner rotor through a cylindrical outer peripheral surface of the radial bearing, and wherein at least one lubrication groove is formed in the cylindrical outer peripheral surface of the radial bearing and accumulates the fluid, which is present in the inside of the pump housing.

2 . The fluid pump according to claim 1 , wherein:
a region of the pump housing, in which at least one of the plurality of pump chambers draws the fluid, is defined as a suction region; another region of the pump housing, in which at least another one of the plurality of pump chambers compresses the fluid, is defined as a compression region; and the at least one lubrication groove is located in an angular extent of the suction region in a rotational direction of the inner rotor.

3 . The fluid pump according to claim 2 , comprising:
a suction passage that is formed in the pump housing and conducts the fluid to be drawn into the at least one of the plurality of pump chambers; and a suction groove that is formed in an inside wall surface of the pump housing and is communicated with the suction passage while the suction groove is shaped to extend along a rotational path of the plurality of external teeth and a rotational path of the plurality of internal teeth, wherein: the at least one lubrication groove is located in an angular extent of the suction groove in the rotational direction.

4 . The fluid pump according to claim 3 , wherein the at least one lubrication groove is located in an angular extent of the suction passage in the rotational direction.

5 . The fluid pump according to claim 1 , wherein:
the radial bearing includes:
a slide portion, which slidably supports the inner rotor; and
a seal portion, which tightly contacts the pump housing; and
the at least one lubrication groove is located in a portion of the cylindrical outer peripheral surface of the radial bearing, which forms the slide portion and is displaced from the seal portion.

Assignees

• Denso Corp

Inventors

• Sakai Hiromi
• Furuhashi Daiji

Classifications

• F05C2253/20

  Resin · CPC title

• F04C2240/56

  Bearing bushings or details thereof · CPC title

• F04C2240/50

  Bearings · CPC title

• F04C15/0092

  Control systems for the circulation of the lubricant · CPC title

• F04C15/06

  Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet · CPC title