VANE OIL PUMP

• US 20180128107A1
• Filed: 10/25/2017
• Published: 05/10/2018
• Est. Priority Date: 11/04/2016
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: INAGAKI, Takafumi, SOGA, Yoshinobu, MORIYAMA, Shuji, OHGATA, Yusuke, HATTORI, Yuji, TUKUDA, Kazumichi, NOBORIO, Akihiko
• Granted Patent: US 10,724,373 B2
• Time in Patent Office: Days
• CPC Class Codes: F01C 21/0836 comprising guiding means, e.g. cams, rollers
• CPC Class Codes: F01C 21/0863 the fluid being the working fluid
• CPC Class Codes: F04C 15/0076 Fixing rotors on shafts, e.g. by clamping together hub and shaft
• CPC Class Codes: F04C 15/066 of the non-return type
• CPC Class Codes: F04C 2/3446 the inner and outer member being in contact along more than one line or surface
• CPC Class Codes: F04C 2/348 the vanes positively engaging, with circumferential play, an outer rotatable member
• CPC Class Codes: F04C 2210/206 Oil
• CPC Class Codes: F04C 2240/20 Rotors
• CPC Class Codes: F04C 2240/30 Casings or housings

Abstract

A vane oil pump includes a rotor including a plurality of slits, a housing having an inner circumferential cam surface such that a first pump unit and a second pump unit taking in and discharging oil in accordance with rotation of the rotor are separately disposed in a rotational direction of the rotor, a plurality of vanes respectively fitted in the slits of the rotor, and a pressure adjusting device configured to adjust a second discharge pressure of the second pump unit to a lower pressure than a first discharge pressure of the first pump unit. A back pressure groove is disposed on the housing and is provided to supply back pressure oil to a bottom portion of each slit.

Claims

1. A vane oil pump comprising:

a rotor including a plurality of slits open on an outer circumferential surface of the rotor;

a housing having an inner circumferential cam surface, the housing accommodating the rotor inside the housing such that the outer circumferential surface of the rotor faces the inner circumferential cam surface, the housing being configured to allow rotation of the rotor with respect to the housing, the inner circumferential cam surface of the housing being configured to have a diameter dimension from a rotational axis of the rotor, and the diameter dimension being configured to increase or decrease in a rotational direction of the rotor such that a first pump unit and a second pump unit taking in and discharging oil in accordance with rotation of the rotor are separately disposed in the rotational direction of the rotor;

a plurality of vanes respectively fitted in the slits of the rotor, a tip end portion of each vane being radially disposed to protrude from the opening of each slit of the rotor, and the vanes being configured to advance or retract with respect to the slits in a radial direction of the rotor; and

a pressure adjusting device configured to adjust a second discharge pressure of the second pump unit to a lower pressure than a first discharge pressure of the first pump unit,

wherein a back pressure groove is disposed on the housing, the back pressure groove is provided to supply back pressure oil to a bottom portion of each slit such that the tip end portion of each vane is pressed to the inner circumferential cam surface, and the back pressure groove is provided such that the back pressure oil supplied to the bottom portion of each slit corresponding to an oil discharge part of the second pump unit has a lower pressure than the back pressure oil supplied to the bottom portion of each slit corresponding to an oil discharge part of the first pump unit when the second discharge pressure is adjusted to a lower pressure than the first discharge pressure.

2. The vane oil pump according to claim 1, wherein:

the back pressure groove includes a first back pressure groove into which first discharged oil of the first pump unit having the first discharge pressure is introduced, and a second back pressure groove into which second discharged oil of the second pump unit having the second discharge pressure is introduced;

the first back pressure groove is provided to supply the back pressure oil to the bottom portion of each slit corresponding to the oil discharge part of the first pump unit; and

the second back pressure groove is provided to supply the back pressure oil to the bottom portion of each slit corresponding to an entirety of the second pump unit and an oil intake part of the first pump unit.

3. The vane oil pump according to claim 1, wherein the back pressure groove is provided to supply the back pressure oil to the bottom portion of each slit corresponding to the oil discharge part of the first pump unit.