Oil pump having extension portions that reduce the effect of #the collapse of bubbles in the oil

Patent metadata

Field	Value
Publication number	US-10174757-B2
Application number	US-201715416383-A
Country	US
Kind code	B2
Filing date	Jan 26, 2017
Priority date	Feb 4, 2016
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

In an oil pump, an inner rotor and an outer rotor rotate to discharge the oil through a discharge port. The discharge port has an outer extension portion located on a radially inner side with respect to a root circle of the outer rotor and on a radially outer side of a tip circle of the outer rotor and an inner extension portion located on the radially inner side with respect to the tip circle of the outer rotor and on the radially outer side with respect to a root circle of the inner rotor. An inter-tooth chamber facing a partitioning portion that partitions the suction port from the discharge port comes into communication with the outer extension portion and the inner extension portion. Then, a tip seal portion defining the inter-tooth chamber intersects an outer edge of an opening of the discharge port.

First claim

What is claimed is:

1. An oil pump comprising:
a pump housing provided with a pump chamber that communicates with a suction port and a discharge port;
an inner rotor having a plurality of tooth profile portions on an outer periphery of the inner rotor; and
an outer rotor having more tooth profile portions on an inner periphery of the outer rotor than the inner rotor and forming a plurality of inter-tooth chambers between the outer rotor and the inner rotor,
wherein the inner rotor and the outer rotor rotate eccentrically in a predetermined rotating direction in the pump housing while meshing with each other to allow oil to be sucked into the pump chamber through the suction port and to allow the oil to be discharged out of the pump chamber through the discharge port,
wherein the inter-tooth chambers are separated from one another by proximate portions, in each of which the tooth profile portion of the inner rotor lies close to the tooth profile portion of the outer rotor,
wherein the pump chamber is formed as a recess that is recessed in a direction of a rotation axis of the inner rotor and the outer rotor, the suction port and the discharge port have openings in a bottom surface of the pump chamber, and a partitioning portion is provided on the bottom surface to partition the suction port from the discharge port,
wherein at a backward end of the discharge port in the rotating direction, an outer extension portion is provided which extends backward in the rotating direction on a radially inner side with respect to a root circle of the outer rotor and on a radially outer side with respect to a tip circle of the outer rotor, and an inner extension portion is also provided which extends backward in the rotating direction on the radially inner side with respect to the tip circle of the outer rotor and on the radially outer side with respect to a root circle of the inner rotor,
wherein when the inner rotor and the outer rotor rotate in the rotating direction, the proximate portion that separates the inter-tooth chamber from other inter-tooth chambers located forward in the rotating direction intersects an outer edge of the opening of the discharge port after the inter-tooth chamber facing the partitioning portion comes into communication with the outer extension portion and the inner extension portion, and
wherein when the inner rotor and the outer rotor rotate in the rotating direction, the inter-tooth chamber facing the partitioning portion comes into communication with the outer extension portion before coming into communication with the inner extension portion, and subsequently, the proximate portion separating the inter-tooth chamber from the other inter-tooth chambers intersects the outer edge of the opening of the discharge port.

2. The oil pump according to claim 1 , wherein,
the inner extension portion is formed of a shallow groove that is shallower than the outer extension portion in the direction of the rotation axis of the inner rotor and the outer rotor.

Assignees

• Jtekt Corp

Inventors

• Oowaki Masaaki

Classifications

• F16N13/20

  Rotary pumps (with distributing equipment F16N13/22) · CPC title

• F04C2270/13

  Noise · CPC title

• F04C2/102

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

• F01M1/02 Primary

  using lubricating pumps (pumps in general F04; lubricating pumps per se F16N) · 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