Pressure source unit

Abstract

A pressure source unit (1) includes: a hydraulic pump (2) including a rotating shaft (21) and a pump housing (22); and an electric motor (6) including an output shaft (61) coupled to the rotating shaft (21) by a coupling mechanism (4), and a motor housing (62). Furthermore, the pressure source unit (1) includes a housing (5) that accommodates the rotating shaft (21), the output shaft (61), and the coupling mechanism (4), and connects the pump housing (22) and the motor housing (62). Working oil is stored in the pump housing (22), and the working oil is supplied into the housing (5).

Description

Technical Field

[0001] The present disclosure relates to a pressure source unit used in a hydraulic circuit. Background Art

[0002] Conventionally, a pressure source unit including a hydraulic pump and an electric motor has been known. For example, a pressure source unit in which the rotation shaft of a hydraulic pump and the output shaft of an electric motor are connected by a key and a keyway is disclosed in FIG. 6 of Patent Document 1. In addition, in Patent Document 1, the pressure source unit is referred to as a "hydraulic generating device".

[0003] In this pressure source unit, the rotation shaft of the hydraulic pump, the output shaft of the electric motor, and the key are accommodated in a sleeve, and through this sleeve, the pump housing of the hydraulic pump is connected to the motor housing of the electric motor.

[0004] Prior Art Documents: Patent Documents: Patent Document 1: Japanese Patent Laid-Open No. 11-314257. Summary of the Invention

[0005] Problems to be Solved by the Invention: In the pressure source unit as described above, various connection mechanisms other than a key and a keyway can be adopted. In addition, lubrication of such a connection mechanism is desired.

[0006] Therefore, an object of the present disclosure is to provide a pressure source unit capable of lubricating a connection mechanism.

[0007] Means for Solving the Problems: The present disclosure provides a pressure source unit including: a hydraulic pump including a rotation shaft and a pump housing; an electric motor including an output shaft connected to the rotation shaft by a connection mechanism and a motor housing; and a housing that accommodates the rotation shaft, the output shaft, and the connection mechanism and connects the pump housing to the motor housing, wherein working oil is stored in the pump housing and supplied to the housing.

[0008] Effects of the Invention: According to the present disclosure, a pressure source unit capable of lubricating a connection mechanism is provided. Brief Description of the Drawings

[0009] Figure 1 is a cross-sectional view of a pressure source unit according to an embodiment; Figure 2 is a cross-sectional view of a part of a pressure source unit according to a first modification; Figure 3 is a cross-sectional view of a part of a pressure source unit according to a second modification; Figure 4Cross-sectional view of a part of the pressure source unit according to the third modified example; Figure 5 Cross-sectional view of the pressure source unit according to the fourth modified example; Detailed implementation mode

[0010] Figure 1 The pressure source unit 1 of one implementation mode is shown. The pressure source unit 1 includes a hydraulic pump 2 and an electric motor 6, and includes a hollow housing 5 interposed between the hydraulic pump 2 and the electric motor 6. In this implementation mode, the hydraulic pump 2 and the electric motor 6 are arranged coaxially.

[0011] In this implementation mode, the hydraulic pump 2 is a swash plate pump as one of the axial piston pumps. However, the hydraulic pump 2 can also be a swash shaft pump as other axial piston pumps. Or, the hydraulic pump 2 can also be other types of pumps such as vane pumps, gear pumps, and screw pumps.

[0012] The hydraulic pump 2 includes: a rotating shaft 21; and a pump housing 22 that rotatably supports the rotating shaft 21 via a plurality of bearings 23, 24. The pump housing 22 is hollow, and a valve plate 31, a cylinder block 32, and a swash plate 36 are accommodated in the pump housing 22.

[0013] More specifically, the pump housing 22 has: a front wall 22a that is penetrated by the rotating shaft 21; a valve cover 22b that is opposed to the front wall 22a in the axial direction of the rotating shaft 21; and a peripheral wall that surrounds the space between the front wall 22a and the valve cover 22b. An intake passage and a discharge passage are formed on the valve cover 22b.

[0014] The valve plate 31 is fixed to the valve cover 22b. An arc-shaped intake port communicating with the intake passage and an arc-shaped discharge port communicating with the discharge passage are formed on the valve plate 31. The intake port and the discharge port are located on the same circumference around the rotating shaft 21.

[0015] 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. A plurality of cylinder bores 32a are formed in the cylinder block 32. Some of the cylinder bores 32a communicate with the intake port, and others communicate with the discharge port.

[0016] A plurality of pistons 33 are respectively inserted into the cylinder bores 32a of the cylinder block 32. A plurality of slippers 34 are respectively mounted on the heads of the pistons 33. In this implementation mode, the slipper 34 slides on the slipper plate 35 fixed to the swash plate 36. However, the slipper 34 can also slide directly on the swash plate 36.

[0017] An oil passage 37 is formed on each piston 33 and the corresponding slipper 34, leading from the cylinder bore 32a to the front end face of the slipper 34. Working oil is supplied from the cylinder bore 32a to the front end face of the slipper 34 through the oil passage 37, and the supplied working oil is used for lubricating the slipper 34. The working oil for lubrication is stored in the pump housing 22.

[0018] The electric motor 6 includes: an output shaft 61; and a motor housing 62 that rotatably supports the output shaft 61 via a plurality of bearings. The motor housing 62 is hollow, and a rotor and a stator are accommodated within the motor housing 62. The rotor is fixed to the output shaft 61, and the stator is fixed to the motor housing 62.

[0019] The rotating shaft 21 of the hydraulic pump 2 and the output shaft 61 of the electric motor 6 are connected by a connecting mechanism 4. In the present embodiment, the connecting mechanism 4 includes a sleeve 40, into which the rotating shaft 21 and the output shaft 61 are inserted. A spline-shaped tooth surface 21a is formed on the outer peripheral surface of the rotating shaft 21. On the other hand, a spline-shaped tooth surface 41 is formed at one end of the inner peripheral surface of the sleeve 40, and the tooth surface 21a and the tooth surface 41 mesh with each other. Similarly, a spline-shaped tooth surface 61a is formed on the outer peripheral surface of the output shaft 61. On the other hand, a spline-shaped tooth surface 42 is formed at the other end of the inner peripheral surface of the sleeve 40, and the tooth surface 61a and the tooth surface 42 mesh with each other.

[0020] However, the connecting mechanism 4 does not necessarily have to include the sleeve 40. Alternatively, one end of either the rotating shaft 21 or the output shaft 61 can be hollow, and the other is inserted therein, such that the spline-shaped tooth surfaces formed on the rotating shaft 21 and the output shaft 61 mesh directly with each other.

[0021] The housing 5 connects the pump housing 22 and the motor housing 62, and accommodates the rotating shaft 21, the output shaft 61, and the connecting mechanism 4. In the present embodiment, the housing 5 is in the shape of a cylinder extending along the axial directions of the rotating shaft 21 and the output shaft 61.

[0022] Moreover, in the present embodiment, the axial directions of the rotating shaft 21 and the output shaft 61 are horizontal, and an oil discharge port 51 is provided at the lower part (e.g., the bottom) of the housing 5. However, the oil discharge port 51 can also be absent. The axial directions of the rotating shaft 21 and the output shaft 61 do not necessarily have to be parallel to the horizontal direction, and can be slightly inclined (e.g., within 10 degrees) with respect to the horizontal direction.

[0023] In the present embodiment, no oil seal is provided between the front wall 22a of the pump housing 22 and the rotary shaft 21. Therefore, the working oil is supplied from inside the pump housing 22 into the housing 5 through the gap between the rotary shaft 21 and the front wall 22a. The outflow of the working oil through the oil discharge port 51 is restricted, whereby the working oil is stored in the housing 5. At this time, the oil level of the working oil may be between the lower end and the upper end of the connecting mechanism 4 so that a part of the connecting mechanism 4 is immersed in the working oil, or may be located above the upper end of the connecting mechanism 4 so that the entire connecting mechanism 4 is immersed in the working oil.

[0024] However, alternatively, an oil seal may be provided between the front wall 22a of the pump housing 22 and the rotary shaft 21, and a through hole communicating the inside of the pump housing 22 with the inside of the housing 5 may be provided in the lower part of the front wall 22a.

[0025] As described above, in the pressure source unit 1 of the present embodiment, since the working oil is supplied into the housing 5 that houses the connecting mechanism 4, the connecting mechanism 4 can be lubricated. When the working oil is stored in such a manner that a part of the connecting mechanism 4 is immersed in the housing 5, the working oil is agitated as the connecting mechanism 4 rotates, and the entire connecting mechanism 4 is lubricated by the splashing of the working oil at this time. And since the working oil stored in the pump housing 22 is used for lubrication, the structure for lubrication can be simplified.

[0026] In addition, in the present embodiment, since the oil discharge port 51 is provided in the housing 5, the working oil in the housing 5 can be circulated. Therefore, deterioration of local lubricating oil such as sealed grease can be prevented.

[0027] Moreover, since the working oil in the housing 5 is refreshed by replacing the working oil in the hydraulic circuit, the maintainability is excellent.

[0028] <Modification Example> The present disclosure is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present disclosure.

[0029] For example, the hydraulic pump 2 may be a series pump or a parallel pump provided with two piston pump mechanisms each including a valve plate 31, a cylinder block 32, a piston 33, a slipper 34, and a swash plate 36.

[0030] In addition, as Figure 2 shown, an air vent port 52 may be provided in the upper part (for example, the top) of the housing 5. If this structure is adopted, when the working oil is supplied into the housing 5, the air in the housing 5 can be discharged through the air vent port 52.

[0031] In addition, as Figure 3As shown, it can also be that the axial directions of the rotating shaft of the hydraulic pump 2 and the output shaft 61 of the electric motor 6 are longitudinal, and the hydraulic pump 2 is located below the electric motor 6. The axial directions of the rotating shaft 21 and the output shaft 61 do not have to be parallel to the vertical direction, and can also be slightly inclined (for example, within 10 degrees) with respect to the vertical direction.

[0032] When the axial directions of the rotating shaft of the hydraulic pump 2 and the output shaft 61 of the electric motor 6 are longitudinal, an air bleeding port 52 can be provided at the upper part of the housing 5. Here, the so-called "upper part of the housing 5" refers to the upper 1 / 3 area when the housing 5 is divided into three equal parts in the vertical direction. According to this structure, the oil level of the working oil stored in the housing 5 can be set at a higher position. In addition, the air bleeding port 52 is preferably provided at a position adjacent to the electric motor 6 on the housing 5. Furthermore, the oil discharge port 51 is preferably located at a position lower than the air bleeding port 52.

[0033] Moreover, as Figure 4 shown, the housing 5 can also have a cylindrical wall 53 surrounding the output shaft 61 of the electric motor 6, which has an end face at a position higher than the air bleeding port 52. According to this structure, the oil level of the working oil stored in the housing 5 can be set above the lower end of the air bleeding port 52.

[0034] In addition, it can also be that, as in the hydraulic system 1A of the modification example shown in Figure 5 the connecting mechanism 4 includes a gear 43 fixed to the rotating shaft 21 of the hydraulic pump 2 and a gear 44 fixed to the output shaft 61 of the electric motor 6, and the tooth surfaces of the gears 43 and 44 mesh with each other. In Figure 5 the gears 43 and 44 are bevel gears, but the gears 43 and 44 can also be spur gears.

[0035] In addition, the connecting mechanism 4 does not have to have tooth surfaces that mesh with each other, and can also be a key and a keyway.

[0036] <Summary> As a first aspect, the present disclosure provides a pressure source unit, which includes: a hydraulic pump, which includes a rotating shaft and a pump housing; an electric motor, which includes an output shaft connected to the rotating shaft through a connecting mechanism and a motor housing; and a housing, which accommodates the rotating shaft, the output shaft and the connecting mechanism, and connects the pump housing and the motor housing, and working oil is stored in the pump housing and supplied to the housing.

[0037] According to the above structure, since the working oil is supplied to the housing that accommodates the connecting mechanism, the connecting mechanism can be lubricated. And since the working oil stored in the pump housing is used for lubrication, the structure for lubrication can be simplified.

[0038] As a second aspect, in the first aspect, it is also possible that an oil drain port is provided on the housing. According to this structure, the working oil in the housing can be circulated. Therefore, it is possible to prevent deterioration of local lubricating oil such as sealed grease.

[0039] As a third aspect, in the second aspect, for example, it is also possible that the axial directions of the rotating shaft of the hydraulic pump and the output shaft of the electric motor are horizontal, an air vent port is provided at the upper part of the housing, and the oil drain port is provided at the lower part of the housing.

[0040] As a fourth aspect, in the first or second aspect, for example, it is also possible that the axial directions of the rotating shaft of the hydraulic pump and the output shaft of the electric motor are vertical, and the hydraulic pump is located below the electric motor.

[0041] As a fifth aspect, in the fourth aspect, it is also possible that an air vent port is provided at the upper part of the housing, and the housing has a cylindrical wall surrounding the output shaft, which has an end face at a position higher than the air vent port. According to this structure, it is possible to set the oil level of the working oil stored in the housing above the lower end of the air vent port.

[0042] As a sixth aspect, in the fifth aspect, for example, it is also possible that an oil drain port is provided on the housing at a position below the air vent port.

[0043] As a seventh aspect, in any one of the first to sixth aspects, for example, it is also possible that the connecting mechanism has tooth surfaces that mesh with each other.

[0044] As an eighth aspect, in any one of the first to seventh aspects, it is also possible that the pump housing has a front wall penetrated by the rotating shaft, and no oil seal is provided between the front wall and the rotating shaft. According to this structure, the working oil is supplied from the inside of the pump housing into the housing through the gap between the rotating shaft and the front wall.

[0045] As a ninth aspect, in any one of the first to eighth aspects, for example, it is also possible that the hydraulic pump includes: a cylinder block fixed to the rotating shaft and having a plurality of cylinder bores; a plurality of pistons inserted into the plurality of cylinder bores; and a plurality of slippers mounted on the heads of the plurality of pistons. The working oil supplied from the plurality of cylinder bores to the front end faces of the plurality of slippers through the oil passages formed in the plurality of pistons and the plurality of slippers is stored in the outer pump after lubricating the plurality of slippers.

Claims

1. A pressure source unit, characterized in that, it comprises: a hydraulic pump including a rotating shaft and a pump housing; an electric motor including an output shaft connected to the rotating shaft through a connecting mechanism and a motor housing; and a housing that houses the rotating shaft, the output shaft and the connecting mechanism, and connects the pump housing and the motor housing, wherein working oil is stored in the pump housing and supplied into the housing.

2. The pressure source unit according to claim 1, characterized in that, an oil drain port is provided on the housing.

3. The pressure source unit according to claim 2, characterized in that, the axial directions of the rotating shaft of the hydraulic pump and the output shaft of the electric motor are horizontal, a vent port is provided at the upper part of the housing, and the oil drain port is provided at the lower part of the housing.

4. The pressure source unit according to claim 1 or 2, characterized in that, the axial directions of the rotating shaft of the hydraulic pump and the output shaft of the electric motor are vertical, and the hydraulic pump is located below the electric motor.

5. The pressure source unit according to claim 4, characterized in that, a vent port is provided at the upper part of the housing, the housing has a cylindrical wall surrounding the output shaft, and has an end face at a position higher than the vent port.

6. The pressure source unit according to claim 5, characterized in that, an oil drain port is provided on the housing at a position below the vent port.

7. The pressure source unit according to claim 1 or 2, characterized in that, the connecting mechanism has tooth surfaces meshing with each other.

8. The pressure source unit according to claim 1 or 2, characterized in that, the pump housing has a front wall penetrated by the rotating shaft, and no oil seal is provided between the front wall and the rotating shaft.

9. The pressure source unit according to claim 1 or 2, characterized in that, the hydraulic pump includes: a cylinder block fixed to the rotating shaft and having a plurality of cylinder bores; a plurality of pistons inserted into the plurality of cylinder bores; and a plurality of slippers mounted on the heads of the plurality of pistons, the working oil supplied from the plurality of cylinder bores to the front end faces of the plurality of slippers through the oil passages formed in the plurality of pistons and the plurality of slippers is stored in the pump housing after lubricating the plurality of slippers.

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