Power transmission apparatus

Patent metadata

Field	Value
Publication number	US-10753358-B2
Application number	US-201615743246-A
Country	US
Kind code	B2
Filing date	Sep 29, 2016
Priority date	Sep 29, 2015
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

A power transmission apparatus includes an oil pump disposed between a hydraulic controller and a strainer. The oil pump includes a rotor (3) and a housing provided with a rotor chamber housing the rotor (3). Rotation of the rotor (3) causes oil to be sucked into an oil chamber (c1) defined by the rotor (3), and the oil is pressurized and discharged therefrom. The housing is provided with a first oil passage (71) through which oil sucked from a reservoir through the strainer flows toward the oil chamber, and a second oil passage (72) through which oil refluxed from the hydraulic controller flows toward the oil chamber. The second oil passage (72) includes a curved oil passage curved along the rotor (3) and is disposed such that the oil refluxed from the hydraulic controller flows in a rotation direction of the rotor (3) through the curved oil passage.

First claim

The invention claimed is:

1. A power transmission apparatus comprising:
an input shaft drivingly coupled by a driving source;
a transmission mechanism to transmit a driving force from the input shaft;
a hydraulic controller to adjust pressure of oil and supply resulting oil to the transmission mechanism;
a reservoir storing oil; and
an oil pump including a rotor and a housing provided with a rotor chamber housing the rotor, the oil pump being configured such that rotation of the rotor causes oil as an excess pressure discharged inside the hydraulic controller and refluxed therefrom and oil sucked from the reservoir through a strainer to be sucked into a pump chamber partitioned by the rotor, and the oil sucked into the pump chamber is pressurized and supplied to the hydraulic controller, wherein
the oil pump is disposed between the hydraulic controller and the strainer as viewed in an axial direction of the rotor,
the housing is provided with a first oil passage through which the oil sucked through the strainer is supplied to the pump chamber, and a second oil passage through which the oil refluxed from the hydraulic controller is supplied to the pump chamber, and
the second oil passage includes a wall surface curved along a rotation direction of the rotor at a position radially outward of an axis of the rotor, so that the oil refluxed from the hydraulic controller flows in a rotation direction of the rotor along the wall surface,
the first oil passage is configured to merge with the second oil passage at a downstream end of the second oil passage in a flow direction of the oil refluxed from the hydraulic controller,
the housing is provided with an opening which is disposed on a first side of the axial direction of the rotor chamber and through which the pump chamber is exposed as viewed in the axial direction,
a portion of a bottom of the first oil passage located away from the rotor chamber in the axial direction is provided with a first inclined region inclined toward the opening in the axial direction,
a portion of a bottom of the second oil passage located away from the rotor chamber in the axial direction is provided with a second inclined region inclined toward the opening in the axial direction and toward a downstream end of the rotation direction of the rotor, and
a second inclined angle of the second inclined region against a vertical plane that is perpendicular to the axial direction is lamer than a first inclined angle of the first inclined region against the vertical plane.

2. The power transmission apparatus according to claim 1 , wherein
the first oil passage merges with the second oil passage at a location downstream of the wall surface of the second oil passage.

3. The power transmission apparatus according to claim 1 , wherein
the wall surface is curved such that a downstream region of the wall surface in the rotation direction of the rotor extends radially inward.

4. The power transmission apparatus according to claim 3 , wherein
the first oil passage includes a wall along which the oil sucked through the strainer flows downstream in the rotation direction of the rotor.

5. The power transmission apparatus according to claim 4 , wherein
the second oil passage is provided such that a sectional area of the second oil passage in a cross section passing through the axis of the rotor decreases as the second oil passage extends downstream in the rotation direction of the rotor along a downstream region of the wall surface.

6. The power transmission apparatus according to claim 5 , wherein
the housing is provided with a second opening disposed on a second side of the axial direction of the rotor chamber,
the housing includes a partition facing the rotor chamber defined around the axis of the rotor and located radially outward of the rotor chamber, the partition defining a third oil passage connecting the first oil passage to the second opening at a radially outward location, and
at least a portion of a radially outward wall surface of the curved oil passage is disposed to overlap with the partition as viewed in the axial direction and is connected at its axial end to the partition.

7. The power transmission apparatus according to claim 6 , wherein
the housing includes a protrusion protruding downstream in the rotation direction of the rotor as viewed in the axial direction, the protrusion including an outer surface facing the first oil passage at a radially outward location relative to a rotation axis of the rotor, and an inner surface facing the second oil passage at a radially inward location, and
the inner surface defines at least a portion of a radially outward wall surface of the wall surface.

8. The power transmission apparatus according to claim 1 , wherein
the housing is provided with a first suction port disposed to face the strainer and connected to the strainer, a second suction port disposed to face the hydraulic controller and connected to the hydraulic controller, and an opening which is disposed on a first side of the axial direction of the rotor chamber and through which the pump chamber is exposed as viewed in the axial direction, and
the first oil passage connects the first suction port to the opening, and the second oil passage connects the second suction port to the opening.

9. The power transmission apparatus according to claim 8 , wherein
the oil pump includes a rotor shaft that rotates together with the rotor, the rotor shaft being disposed in parallel with the input shaft, the rotor being rotated by providing power from the driving source to the rotor shaft through a transmission member that drivingly couples the input shaft to the rotor shaft.

10. The power transmission apparatus according to claim 9 , the apparatus comprising a case housing the transmission mechanism, wherein
the hydraulic controller is disposed on a lateral surface of the case,
the reservoir is provided in a lower portion of the case, and
the oil pump is disposed below the input shaft.

11. The power transmission apparatus according to claim 10 , wherein
the rotor is a drive gear including external teeth, and
the oil pump includes a driven gear that includes internal teeth meshing with the external teeth, the driven gear being housed in the rotor chamber so as to be eccentric relative to the drive gear, the driven gear being configured to rotate in accordance with rotation of the drive gear.

12. The power transmission apparatus according to claim 11 , wherein
the housing includes a pump body provided with the rotor chamber, and a cover body secured to the pump body so as to cover a first side of the axial direction of the pump body, the cover body being provided with the first oil passage and the second oil passage.

13. The power transmission apparatus according to claim 1 , wherein
the first oil passage includes a wall along which the oil sucked through the strainer flows downstream in the rotation direction of the rotor.

14. The power transmission apparatus according to claim 13 , wherein
the second oil passage is provided such that a sectional area of the second oil passage in a cross section passing through the axis of the rotor decreases as the second oil passage extends downstream in the rotation direction of the rotor along a downstream region of the wall surface.

15. The power transmission apparatus according to claim 1 wherein
the second oil passage is provided such that a sectional area of the second oil passage in a cross section passing through the axis of the rotor decreases as the second oil passage extends downstream in the rotation direction of th

Assignees

• Aisin Aw Co

Inventors

• Saito Naoki
• Torii Takeshi
• Chujo Atsushi

Classifications

• F16H41/00

  Rotary fluid gearing of the hydrokinetic type (control of exclusively fluid gearing F16H61/38) · CPC title

• F16H57/0436

  Pumps · CPC title

• F04C2270/185

  Controlled or regulated · CPC title

• F16H57/12

  Arrangements for adjusting or for taking-up backlash not provided for elsewhere · CPC title

• F04C2/102

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