US-20260126031-A1 - PRESSURE SOURCE UNIT

US20260126031A1US 20260126031 A1US20260126031 A1US 20260126031A1US-20260126031-A1

Abstract

A pressure source unit includes: a hydraulic pump including a rotating shaft and a pump casing; and an electric motor including an output shaft and a motor casing, the output shaft being coupled to the rotating shaft by a coupling structure. The pressure source unit further includes a housing that accommodates therein the rotating shaft, the output shaft, and the coupling structure, the housing connecting between the pump casing and the motor casing. Hydraulic oil is stored in the pump casing, and the hydraulic oil is supplied into the housing.

Inventors

Kenta Kano
Hideki Tanaka
Takanobu Nakamura
Atsuhito HIGUCHI
Yukito Imamura

Assignees

KAWASAKI JUKOGYO KABUSHIKI KAISHA

Dates

Publication Date: 20260507
Application Date: 20230904
Priority Date: 20221115

Claims (13)

1 . A pressure source unit comprising: a hydraulic pump including a rotating shaft and a pump casing; an electric motor including an output shaft and a motor casing, the output shaft being coupled to the rotating shaft by a coupling structure; and a housing that accommodates therein the rotating shaft, the output shaft, and the coupling structure, the housing connecting between the pump casing and the motor casing, wherein hydraulic oil is stored in the pump casing, and the hydraulic oil is supplied into the housing.
2 . The pressure source unit according to claim 1 , wherein the housing includes a drain port.
3 . The pressure source unit according to claim 2 , wherein an axial direction of the rotating shaft of the hydraulic pump and the output shaft of the electric motor extends horizontally, and an upper portion of the housing includes an air vent port, and a lower portion of the housing includes the drain port.
4 . The pressure source unit according to claim wherein an axial direction of the rotating shaft of the hydraulic pump and the output shaft of the electric motor extends vertically, and the hydraulic pump is positioned below the electric motor.
5 . The pressure source unit according to claim 4 , wherein an upper portion of the housing includes an air vent port, and the housing includes a tubular wall that includes an end surface located at a position higher than a position of the air vent port, the tubular wall surrounding the output shaft.
6 . The pressure source unit according to claim 5 , wherein the housing includes a drain port that is located below the air vent port.
7 . The pressure source unit according to claim 1 , wherein the coupling structure includes toothed surfaces that mesh with each other.
8 . The pressure source unit according to claim 1 , wherein the pump casing includes a front wall that is penetrated by the rotating shaft, and there is no oil seal between the front wall and the rotating shaft.
9 . The pressure source unit according to claim 1 , wherein the hydraulic pump includes: a cylinder block fixed to the rotating shaft and including cylinder bores; pistons that are received in the respective cylinder bores; and shoes that are mounted to heads of the respective pistons, the pistons and the shoes include oil passages, through which the hydraulic oil is supplied from the cylinder bores to distal end surfaces of the respective shoes, and the hydraulic oil that has been supplied to the distal end surfaces of the respective shoes lubricates the shoes, and is then stored in the pump casing.
10 . The pressure source unit according to claim 2 , wherein an axial direction of the rotating shaft of the hydraulic pump and the output shaft of the electric motor extends vertically, and the hydraulic pump is positioned below the electric motor.
11 . The pressure source unit according to claim 2 , wherein the coupling structure includes toothed surfaces that mesh with each other.
12 . The pressure source unit according to claim 2 , wherein the pump casing includes a front wall that is penetrated by the rotating shaft, and there is no oil seal between the front wall and the rotating shaft.
13 . The pressure source unit according to claim 2 , wherein the hydraulic pump includes: a cylinder block fixed to the rotating shaft and including cylinder bores; pistons that are received in the respective cylinder bores; and shoes that are mounted to heads of the respective pistons, the pistons and the shoes include oil passages, through which the hydraulic oil is supplied from the cylinder bores to distal end surfaces of the respective shoes, and the hydraulic oil that has been supplied to the distal end surfaces of the respective shoes lubricates the shoes, and is then stored in the pump casing

Description

TECHNICAL FIELD The present disclosure relates to a pressure source unit for use in a hydraulic circuit. BACKGROUND ART Conventionally, there is a known pressure source unit including a hydraulic pump and an electric motor. For example, FIG. 6 of Patent Literature 1 discloses a pressure source unit in which the rotating shaft of a hydraulic pump and the output shaft of an electric motor are coupled to each other by a key and a key groove. In Patent Literature 1, the pressure source unit is referred to as a “hydraulic pressure generator”. In the pressure source unit, the rotating shaft of the hydraulic pump, the output shaft of the electric motor, and the key are accommodated in a sleeve, and a pump casing of the hydraulic pump and a motor casing of the electric motor are connected to each other by the sleeve. Citation List Patent Literature PTL 1: Japanese Laid-Open Patent Application Publication No. H11-314257 SUMMARY OF INVENTION Technical Problem In the above-described pressure source unit, various coupling structures other than the key and the key groove are adoptable. There is a desire to lubricate such a coupling structure. An object of the present disclosure is to provide a pressure source unit capable of lubricating a coupling structure. Solution to Problem The present disclosure provides a pressure source unit including: a hydraulic pump including a rotating shaft and a pump casing; an electric motor including an output shaft and a motor casing, the output shaft being coupled to the rotating shaft by a coupling structure; and a housing that accommodates therein the rotating shaft, the output shaft, and the coupling structure, the housing connecting between the pump casing and the motor casing. Hydraulic oil is stored in the pump casing, and the hydraulic oil is supplied into the housing. Advantageous Effects of Invention The present disclosure provides a pressure source unit capable of lubricating a coupling structure. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a sectional view of a pressure source unit according to one embodiment. FIG. 2 is a sectional view of a part of a first variation of the pressure source unit. FIG. 3 is a sectional view of a part of a second variation of the pressure source unit. FIG. 4 is a sectional view of a part of a third variation of the pressure source unit. FIG. 5 is a sectional view of a fourth variation of the pressure source unit. DESCRIPTION OF EMBODIMENTS FIG. 1 shows a pressure source unit 1 according to one embodiment. The pressure source unit 1 includes: a hydraulic pump 2; an electric motor 6; and a hollow housing 5 located between the hydraulic pump 2 and the electric motor 6. In the present embodiment, the hydraulic pump 2 and the electric motor 6 are located coaxially. In the present embodiment, the hydraulic pump 2 is a swash plate pump that is one type of axial piston pump. Alternatively, the hydraulic pump 2 may be a bent axis pump that is another type of axial piston pump. Further alternatively, the hydraulic pump 2 may be a different type of pump, such as a vane pump, a gear pump, or a screw pump. The hydraulic pump 2 includes: a rotating shaft 21; and a pump casing 22, which supports the rotating shaft 21 via bearings 23 and 24 such that the rotating shaft 21 is rotatable. The pump casing 22 is a hollow casing, and a valve plate 31, a cylinder block 32, and a swash plate 36 are accommodated in the pump casing 22. To be more specific, the pump casing 22 includes: a front wall 22a, which is penetrated by the rotating shaft 21; a valve cover 22b, which faces the front wall 22a in the axial direction of the rotating shaft 21; and a peripheral wall that surrounds a space between the front wall 22a and the valve cover 22b. The valve cover 22b includes a suction passage and a delivery passage. The valve plate 31 is fixed to the valve cover 22b. The valve plate 31 includes: an arc-shaped suction port that communicates with the suction passage; and an arc-shaped delivery port that communicates with the delivery passage. The suction port and the delivery port are located on the same circumference about the rotating shaft 21. The cylinder block 32 is fixed to the rotating shaft 21, and rotates together with the rotating shaft 21 while sliding on the valve plate 31. The cylinder block 32 includes cylinder bores 32a. Some of the cylinder bores 32a communicate with the suction port, and some of the other cylinder bores 32a communicate with the delivery port. Pistons 33 are received in the respective cylinder bores 32a of the cylinder block 32. Shoes 34 are mounted to the heads of the respective pistons 33. In the present embodiment, the shoes 34 slide on a shoe plate 35 fixed to the swash plate 36. Alternatively, the shoes 34 may directly slide on the swash plate 36. Each piston 33 and the corresponding shoe 34 include an oil passage 37, which extends from the cylinder bore 32a to the distal end surface of the shoe 34. Hydraulic oil is supplied from the cylinder bor