US 12,448,967 B2
Variable displacement oil pump
Nobuaki Sogawa, Hitachinaka (JP); Koji Saga, Hitachinaka (JP); and Daisuke Kato, Hitachinaka (JP)
Assigned to Hitachi Astemo, Ltd., Hitachinaka (JP)
Appl. No. 18/683,837
Filed by Hitachi Astemo, Ltd., Hitachinaka (JP)
PCT Filed Jul. 5, 2022, PCT No. PCT/JP2022/026651
§ 371(c)(1), (2) Date Feb. 15, 2024,
PCT Pub. No. WO2023/037736, PCT Pub. Date Mar. 16, 2023.
Claims priority of application No. 2021-145848 (JP), filed on Sep. 8, 2021.
Prior Publication US 2024/0369060 A1, Nov. 7, 2024
Int. Cl. F04C 14/22 (2006.01); F04C 2/34 (2006.01); F04C 2/344 (2006.01); F04C 15/00 (2006.01)
CPC F04C 15/0065 (2013.01) [F04C 2/3442 (2013.01); F04C 14/22 (2013.01); F04C 14/223 (2013.01); F04C 14/226 (2013.01); F04C 15/0003 (2013.01); F04C 2210/206 (2013.01); F04C 2240/30 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A variable displacement oil pump comprising:
a housing having a pump accommodating portion;
an adjusting member provided in the pump accommodating portion so as to be able to pivot on a pivot as a rotation shaft that is provided at the pump accommodating portion;
a pump member accommodated inside the adjusting member and driven and rotated by a drive shaft passing through a rotation center that is eccentric to a center of an inner circumference of the adjusting member, wherein a plurality of working chambers are defined between the pump member and the adjusting member, oil is sucked into some working chambers of the plurality of working chambers through a suction portion that is provided so as to straddle the adjusting member in a radial direction of the drive shaft according to rotation of the pump member, and oil in the some working chambers of the plurality of working chambers is discharged through a discharge portion that is provided so as to straddle the adjusting member in the radial direction according to the rotation of the pump member;
a first control hydraulic chamber formed between the pump accommodating portion and the adjusting member in the radial direction, wherein a volume of the first control hydraulic chamber increases when oil discharged from the discharge portion is led to the first control hydraulic chamber and the adjusting member moves in a direction in which an eccentric amount of the center of the inner circumference of the adjusting member from the rotation center of the drive shaft decreases; and
an urging member forcing the adjusting member in a direction in which the eccentric amount of the center of the inner circumference of the adjusting member from the rotation center of the drive shaft increases by contacting the adjusting member, wherein the urging member is provided between the pump accommodating portion and the adjusting member and located at a position that faces the drive shaft in the radial direction and that does not overlap the suction portion when viewed from an axial direction along the drive shaft, wherein
the urging member is accommodated in an urging member accommodating chamber liquid-tightly sealed between the pump accommodating portion and the adjusting member, and
a distance between a discharge side seal portion liquid-tightly sealing a clearance between the discharge portion and the urging member accommodating chamber and a center of the urging member is shorter than a distance between a suction side seal portion liquid-tightly sealing a clearance between the suction portion and the urging member accommodating chamber and the center of the urging member.