Electric pump unit

Abstract

To improve cooling efficiency of a control unit.SOLUTION: An electric pump unit 105 includes an electric pump 100. The electric pump 100 has a housing 40 which houses a pump part 10, a motor part 20, and a control unit 30. The housing 40 has: a suction port 45; an axial wall 49 which protrudes from an outer peripheral surface of the housing 40 and extends in an axial direction of a drive shaft 1; and a partition part 42 which separates the motor part 20 from the control unit 30. In the partition part 42, a cooling passage 48 which is formed penetrating through the partition part 42 and allows a fluid suctioned into the pump part 10 to pass therethrough, and two opening parts 48a serving as an inlet and an outlet of the cooling passage 48 are formed. The axial wall 49 is formed between the two opening parts 48 of the cooling passage 48 in a circumferential direction of the drive shaft 1.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electric pump unit. [Background technology]

[0002] Patent Document 1 discloses an electric pump unit in which a pump, an electric motor for driving the pump, and a motor controller are assembled in a unit housing. The controller has a board on which electronic components such as a capacitor are mounted, and is accommodated in the unit housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-112302 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an electric pump unit such as that described in Patent Document 1, the electronic components of the controller generate heat during operation, and the heat is transferred to the unit housing. The unit housing is cooled by outside air, thereby cooling the controller (electronic components). In an electric pump unit such as that described in Patent Document 1, the controller is cooled by air in this manner, and therefore there is room for improving the cooling efficiency of the controller.

[0005] The present invention has been made in consideration of the above problems, and has an object to improve the cooling efficiency of a control unit. [Means for solving the problem]

[0006] The present invention is an electric pump unit comprising an electric pump, an attachment body having an accommodation portion in which the electric pump is accommodated, and a space formed between the electric pump and the accommodation portion through which a fluid flows, the electric pump having a pump portion that discharges fluid, a motor portion that rotates a drive shaft to drive the pump portion, a control portion that controls the motor portion, and a housing that accommodates the pump portion, the motor portion, and the control portion, the housing having a suction port that directs fluid in the space to the pump portion, an axial wall that protrudes from the outer peripheral surface of the housing and extends in the axial direction of the drive shaft, and a partition portion that separates the motor portion and the control portion, the partition portion having a cooling passage that is formed through the partition portion and through which the fluid sucked into the pump portion passes, and two openings that are an inlet and an outlet of the cooling passage, the axial wall being formed between the two openings of the cooling passage in the circumferential direction of the drive shaft.

[0007] In this invention, heat generated by electronic components of the control unit when the electric pump is driven is transferred to the partition. A cooling passage is formed in the partition, and the partition is cooled by the fluid passing through the cooling passage, thereby cooling the control unit. In this way, the cooling efficiency of the control unit can be improved by cooling the control unit using the fluid sucked into the pump unit. Furthermore, the axial wall obstructs the flow of the fluid that flows along the outer circumferential surface of the housing and is guided to the suction port, increasing the flow rate guided to the cooling passage, thereby efficiently cooling the control unit.

[0008] In addition, the present invention is characterized in that a pair of axial walls are provided circumferentially spaced apart to separate the space into two, and two openings of the cooling passage are separated by the pair of axial walls.

[0009] In this invention, since the space is divided into two by the axial wall, the fluid is guided from one space to the other space through the cooling passage, so that the flow rate guided to the cooling passage is increased, and the control unit can be cooled efficiently.

[0010] The present invention is also characterized in that the housing has two suction ports, the mounting body has a supply passage formed therein that communicates with the space and supplies fluid to the space, and the housing further has a circumferential wall formed between the supply passage and the suction port close to the supply passage and extending in the circumferential direction of the drive shaft, the circumferential wall providing resistance to the flow of fluid from the supply passage to the suction port close to the supply passage.

[0011] In this invention, resistance is applied to the fluid guided to the suction port close to the supply passage, thereby increasing the flow rate guided to the cooling passage and the suction port far from the supply passage, thereby efficiently cooling the control unit.

[0012] The present invention is also characterized in that the housing has two suction ports, a supply passage is formed in the mounting body which communicates with the space and supplies fluid to the space, and a flow rate adjustment portion is formed in the axial wall or between the axial wall and the accommodating portion, and fluid is guided through the flow rate adjustment portion to the suction port far from the supply passage.

[0013] In this invention, since the fluid is guided to the suction port not only through the cooling passage but also through the flow rate adjusting portion, the flow rate guided to the suction port can be controlled by adjusting the shape of the flow rate adjusting portion. Effect of the Invention

[0014] According to the present invention, the cooling efficiency of the control unit can be improved. [Brief description of the drawings]

[0015] [Figure 1] 1 is a perspective view of an electric pump according to an embodiment of the present invention; [Diagram 2] 1 is a cross-sectional view of an electric pump according to an embodiment of the present invention. [Diagram 3] 1 is a side view of an electric pump unit according to an embodiment of the present invention, showing a state in which the electric pump is attached to a mounting body, the mounting body being shown in cross section. [Figure 4]FIG. 2 is a schematic diagram showing the flow of a fluid introduced into a suction port, and corresponds to FIG. 1. [Diagram 5] FIG. 11 is a diagram showing an electric pump unit according to a third modified example of the embodiment of the present invention. [Figure 6] FIG. 13 is a diagram showing an electric pump unit according to a fifth modified example of the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] An electric pump unit 105 according to an embodiment of the present invention will now be described with reference to the drawings. The electric pump unit 105 includes an electric pump 100 and a mounting body 101 to which the electric pump 100 is mounted.

[0017] First, the configuration of the electric pump 100 will be described in detail. The electric pump 100 is mounted on, for example, a vehicle and discharges a coolant (fluid) for cooling an electric motor mounted on the vehicle, or discharges oil (fluid) for lubricating gears mounted on the vehicle. The electric pump 100 may be used as a fluid pressure supply source that discharges a working fluid for driving equipment. The electric pump 100 may also be mounted on industrial machinery other than a vehicle.

[0018] FIG. 1 is a perspective view of an electric pump 100, and FIG. 2 is a cross-sectional view of the electric pump 100 as viewed from the front side in FIG. 1. As shown in FIGS. 1 and 2, the electric pump 100 includes a pump section 10 that discharges a fluid, a motor section 20 that drives the pump section 10 by rotating a drive shaft 1, a control section 30 that controls the motor section 20, and a housing 40 that accommodates the pump section 10, the motor section 20, and the control section 30. In the electric pump 100, the control section 30, the motor section 20, and the pump section 10 are arranged in this order from the top in FIGS. 1 and 2. Hereinafter, the axial direction of the drive shaft 1 will be simply referred to as the "axial direction", the radial direction of the drive shaft 1 will be simply referred to as the "radial direction", and the circumferential direction of the drive shaft 1 will be simply referred to as the "circumferential direction".

[0019] In this embodiment, the pump section 10 is a vane pump. As shown in Fig. 2, the pump section 10 has a pump rotor 11, a vane (not shown), a cam ring 12, a first side plate 13, a second side plate 14, and a pump chamber 15. The configuration and operation of the vane pump are similar to those of a well-known configuration, and therefore detailed description will be omitted. The pump section 10 is accommodated in a housing body section 41 and a pump cover section 44 of a housing 40, which will be described later.

[0020] As shown in FIG. 1, the housing main body 41 has a suction port 45 that guides fluid from the outside to the pump chamber 15 of the pump section 10. Note that FIG. 2 shows a cross section that does not include the suction port 45. The pump cover section 44 is formed with a discharge port 46 that guides fluid discharged from the pump chamber 15 to the outside. With the rotation of the pump rotor 11, fluid is sucked in through the suction port 45 in the suction region where the pump chamber 15 expands, and fluid is discharged in the discharge region where the pump chamber 15 contracts and is guided to the outside through the discharge port 46. In this embodiment, two (a pair) of suction ports 45 are provided so as to face each other across the drive shaft 1. That is, only one suction port 45 is shown in FIG. 1, and another suction port 45 is formed on the back side of the paper.

[0021] 2, the motor section 20 has an annular stator 21 and a motor rotor 25 disposed radially inside the stator 21. The stator 21 and the motor rotor 25 are housed in a housing 40 (specifically, a housing main body section 41).

[0022] The stator 21 has an annular stator core 22 provided to surround the motor rotor 25, and a coil wire 23 wound around the stator core 22. The stator core 22 has an annular yoke portion 22a in contact with the inner peripheral surface of the housing 40 (housing main body portion 41), and a plurality of teeth portions 22b protruding radially inward from the yoke portion 22a and arranged at predetermined intervals in the circumferential direction. The coil wire 23 is wound around the teeth portions 22b of the stator core 22, so that a U-phase coil, a V-phase coil, and a W-phase coil corresponding to the three-phase drive current are formed on each of the teeth portions 22b. An end of each coil wire 23 is connected to the control portion 30.

[0023] The motor rotor 25 has a rotor core 25a that is provided on the outer circumferential surface of the drive shaft 1 and rotates together with the drive shaft 1, and a plurality of permanent magnets 25b that are provided on the outer circumferential surface of the rotor core 25a. The permanent magnets 25b are provided in an annular shape, with N poles and S poles arranged alternately. In the motor section 20, the motor rotor 25 rotates about the drive shaft 1 as an axis due to the interaction between the magnetized state of the stator core 22 of the stator 21 and the permanent magnets 25b. This drives the pump section 10.

[0024] The control unit 30 controls the current supplied to the stator 21 to drive the motor unit 20. The control unit 30 has a substrate 32 on which electronic components 31 are mounted. The electronic components 31 include, for example, a magnetic detection sensor such as a Hall element capable of detecting a change in magnetism that changes according to the rotation of the drive shaft 1, a calculation unit that calculates the rotation angle and rotation speed of the drive shaft 1 based on the detection value of the magnetic detection sensor, and a transistor. The coil wire 23 of the motor unit 20 is electrically connected to the substrate 32. The control unit 30 controls the direction of the current flowing through the coil wire 23 of the stator 21 according to the rotation angle of the drive shaft 1, and controls the magnitude of the current supplied to the coil wire 23 so that the rotation speed of the drive shaft 1 becomes a target rotation speed input from the outside. The control unit 30 is provided with the electronic components 31 in contact with the housing 40.

[0025] As shown in Figures 1 and 2, the housing 40 has a housing main body portion 41 having an opening 41a (see Figure 2), a partition portion 42 covering the opening 41a and separating the motor portion 20 and the control portion 30, a cover portion 43 connected to the partition portion 42 and covering the control portion 30, a pump cover portion 44 that accommodates and covers the pump portion 10, and an axial wall 49 protruding from the outer circumferential surface of the housing 40.

[0026] As shown in FIG. 2, the housing body 41 has an insertion hole 41b through which the drive shaft 1 is inserted, an annular motor accommodating recess 41c in which the motor unit 20 is accommodated, and a pump accommodating recess 41e in which the pump unit 10 is accommodated. The insertion hole 41b extends in the axial direction across the opening 41a and the pump accommodating recess 41e, and is formed radially inside the motor accommodating recess 41c. The motor accommodating recess 41c is formed continuously with the opening 41a, and an annular yoke portion 22a of the stator core 22 of the motor unit 20 is provided in contact with the inner peripheral surface. The insertion hole 41b accommodates a bearing 50 provided on the outer peripheral surface of the drive shaft 1 and rotatably supporting the drive shaft 1, and an oil seal 60. The pump accommodating recess 41e accommodates the first side plate 13, a part of the pump rotor 11, and a part of the cam ring 12. The housing body 41 is connected to the partition portion 42 by a fastening member 82 (see FIG. 1). As described above, a pair of suction ports 45 (see FIG. 1) are formed in the housing body 41. The suction ports 45 are formed across the housing body 41 and the pump cover portion 44.

[0027] The partition 42 is provided separately from the housing main body 41, and is connected to the housing main body 41 while covering the opening 41a of the housing main body 41. The partition 42 is formed with a concave accommodating portion 42a in which the control unit 30 is accommodated. The accommodating portion 42a is formed at the end opposite to the housing main body 41, and accommodates the electronic components 31 and the board 32 of the control unit 30. The board 32 is electrically connected to the outside by a connector (not shown) provided on the housing 40. The partition 42 is formed with a small diameter on the housing main body 41 side and a large diameter on the control unit 30 side, and a shoulder surface 42d is formed between the two.

[0028] A cooling passage 48 (see FIG. 1 and FIG. 2) is formed in the partition 42. In FIG. 1, the opening area where the cooling passage 48 is formed is indicated by hatching. The cooling passage 48 is formed so as to be located between the electronic components 31 of the control unit 30 and the motor unit 20. The cooling passage 48 is formed so as to extend linearly and penetrate the partition 42. Therefore, the partition 42 is formed with two openings 48a, 48b (see FIG. 3) which are the inlet and outlet of the cooling passage 48. The cooling passage 48 is formed to cool the control unit 30. The cooling passage 48 will be described in detail later. The partition 42 is formed with an insertion hole 42c into which an end of the drive shaft 1 is inserted, and the insertion hole 42c accommodates a bearing 51 provided on the outer circumferential surface of the drive shaft 1 and rotatably supporting the drive shaft 1.

[0029] The cover portion 43 has a protrusion 43a that protrudes on the side opposite to the housing main body portion 41 (upward in FIG. 2). The protrusion 43a is formed hollow and is provided so as to cover the substrate 32 of the control portion 30. The cover portion 43 is fixed to the partition portion 42 by a fastening member 81.

[0030] The pump cover portion 44 is provided so as to cover the pump accommodating recess 41e, and is fixed to the housing body portion 41 by fastening members 83 (see FIG. 1). The pump cover portion 44 is formed with a protruding portion 44a that protrudes toward the side opposite the motor portion 20, and a discharge port 46 is formed in the protruding portion 44a. An annular seal member 61 is provided on the outer circumferential surface of the protruding portion 44a. As described above, the pump cover portion 44 is formed with a pair of suction ports 45 across the housing body portion 41.

[0031] The axial wall 49 protrudes in the radial direction from the outer circumferential surface of the housing 40. The axial wall 49 has a first axial wall 49a and a second axial wall 49c extending in the axial direction. That is, in this embodiment, a pair of axial walls 49 is provided. In this embodiment, the first axial wall 49a and the second axial wall 49c are provided circumferentially separated from each other and facing each other with the drive shaft 1 in between. The first axial wall 49a and the second axial wall 49c are formed between the two suction ports 45 and between the two openings 48a, 48b of the cooling passage 48 in the circumferential direction of the drive shaft 1. The first axial wall 49a and the second axial wall 49c are formed from the shoulder surface 42d of the partition portion 42 to the outer circumferential surface of the housing main body portion 41 and the outer circumferential surface of the pump cover portion 44, respectively. The first axial wall 49a and the second axial wall 49c have top surfaces 49b, 49d extending in the axial direction, and the top surfaces 49b, 49d are located between the inner peripheral edge and the outer peripheral edge of the shoulder surface 42d of the partition portion 42. In this embodiment, the first axial wall 49a is provided at a position closer to a supply passage 102 (described later) than the second axial wall 49c. The first axial wall 49a and the second axial wall 49c are configured symmetrically with respect to the drive shaft 1, and therefore, hereinafter, the first axial wall 49a and the second axial wall 49c will also be collectively referred to simply as "axial walls 49".

[0032] Next, the configuration of the mounting body 101 and the mounting of the electric pump 100 will be described in detail.

[0033] As shown in Fig. 3, the electric pump unit 105 includes a mounting body 101 having a housing portion 101a in which the electric pump 100 is housed, and a space 70 formed between the electric pump 100 and the housing portion 101a through which a fluid flows. Fig. 3 is a side view showing a state in which the electric pump 100 is mounted on the mounting body 101, and Fig. 4 is a schematic diagram showing the flow of a fluid guided to the suction port 45. Note that Fig. 3 shows the mounting body 101 in cross section, and also shows the opening 48b of the cooling passage 48 on the rear side of the paper, the suction port 45b on the rear side of the paper, and the flow of the fluid on the rear side of the paper (arrow C) by dotted lines. Also, Fig. 4 shows the mounting body 101 by dotted lines.

[0034] 3 and 4, the electric pump 100 is mounted to be accommodated in a recessed accommodation portion 101a of a mounting body 101. The accommodation portion 101a is formed in a stepped shape having a large diameter portion 101b and a small diameter portion 101c.

[0035] When the electric pump 100 is attached to the mounting body 101, the shoulder surface 42d of the partition portion 42 contacts the end surface of the mounting body 101, and the tip of the protruding portion 44a of the pump cover portion 44 is housed in the small diameter portion 101c. Also, the tip of the axial wall 49 (the first axial wall 49a and the second axial wall 49c) contacts the step portion 101d between the large diameter portion 101b and the small diameter portion 101c of the housing portion 101a. Furthermore, the housing main body portion 41, the partition portion 42 on the housing main body portion 41 side relative to the shoulder surface 42d, a part of the pump cover portion 44, and the axial wall 49 are housed in the large diameter portion 101b. The large diameter portion 101b is formed with a larger diameter than the housing body 41, the shoulder surface 42d of the partition portion 42, and the pump cover portion 44, and a space 70 is formed between the outer peripheral surface of the housing 40 and the inner peripheral surface of the large diameter portion 101b. The space 70 communicates with a supply passage 102 formed in the mounting body 101. The space 70 is supplied with a fluid guided to the suction port 45 of the electric pump 100 through the supply passage 102. That is, the fluid is guided to the suction port 45 of the electric pump 100 through the supply passage 102 and the space 70. In addition, in FIG. 3 and FIG. 4, the supply passage 102 communicates with the space 70 on the front side of the paper surface of the first axial wall 49a.

[0036] The first axial wall 49a and the second axial wall 49c are provided to separate the space 70 into two. Specifically, the first axial wall 49a is provided such that a top surface 49b contacts the inner circumferential surface of the large diameter portion 101b of the storage portion 101a, and the second axial wall 49c is provided such that a top surface 49d contacts the inner circumferential surface of the large diameter portion 101b of the storage portion 101a. In other words, the first axial wall 49a and the second axial wall 49c are formed so that the top surfaces 49b, 49d contact the inner circumferential surface of the large diameter portion 101b in accordance with the shape of the large diameter portion 101b of the storage portion 101a. As a result, the space 70 is separated into a first space 70a (the front side of the paper in FIGS. 3 and 4) that communicates with the supply passage 102 and a second space 70b (the rear side of the paper in FIGS. 3 and 4) that does not communicate with the supply passage 102. A pair of axial walls 49 separate the two suction ports 45 and also separate the two openings 48a, 48b of the cooling passage 48 (see FIG. 3).

[0037] Next, the flow of fluid in the space 70 and the function of the cooling passages 48 will be described in detail.

[0038] The fluid supplied from the supply passage 102 to the space 70 is guided to the two suction ports 45. Specifically, as shown by arrow A in Figures 3 and 4, the fluid is directly guided from the supply passage 102 to the first suction port 45a located in the first space 70a and close to the supply passage 102. In contrast, the fluid is not directly guided from the supply passage 102 to the second suction port 45b (see Figure 3) located in the second space 70b and far from the supply passage 102, but is guided to the second suction port 45b that has passed through the cooling passage 48 because the space 70 is separated by the axial wall 49. Specifically, as shown by arrow B in Figures 3 and 4, the fluid supplied from the supply passage 102 to the space 70a flows into the cooling passage 48 from the first opening 48a (inlet) located in the first space 70a and close to the supply passage 102 in the cooling passage 48. Since the cooling passage 48 is formed to extend linearly and penetrate the partition portion 42, the fluid that has passed through the cooling passage 48 flows out from the second opening 48b (outlet) far from the supply passage 102 (in the second space 70b) into the second space 70b, and is guided to the second suction port 45b as shown by the arrow C in Fig. 4. In this way, the fluid from the supply passage 102 is guided to the two suction ports 45 via two routes.

[0039] Here, in the electric pump 100 of this embodiment, the electronic component 31 of the control unit 30 generates heat during operation. The electronic component 31 comes into contact with the partition portion 42 of the housing 40, and the heat is transferred to the partition portion 42. Since the cooling passage 48 is formed in the partition portion 42, the partition portion 42 is cooled by the fluid passing through the cooling passage 48, and the electronic component 31 is cooled. In this way, the control unit 30 is cooled by using the fluid sucked into the pump portion 10, rather than air cooling, so that the cooling efficiency of the control unit 30 can be improved. Furthermore, due to the axial wall 49 (the first axial wall 49a and the second axial wall 49c), the fluid is not directly guided from the supply passage 102 to the second suction port 45b, but the fluid that has passed through the cooling passage 48 is guided thereto. That is, in this embodiment, the space 70 is divided into two by the axial wall 49, and therefore the fluid is guided from one space 70a to the other space 70b through the cooling passage 48. Therefore, the flow rate guided to the cooling passage 48 increases, so that the control unit 30 can be cooled efficiently.

[0040] In this embodiment, the top surfaces 49b, 49d of the axial wall 49 are provided in contact with the inner circumferential surface of the large diameter portion 101b of the accommodation portion 101a, so that the axial wall 49 functions as a guide when the electric pump 100 is accommodated in the accommodation portion 101a. Therefore, the electric pump 100 can be easily attached to the attachment target 101.

[0041] In this embodiment, the cooling passages 48 are formed in correspondence with the positions of the electronic components 31 on the substrate 32. Specifically, the cooling passages 48 are formed in positions that overlap with the electronic components 31 in the axial direction. This allows the cooling of positions close to the electronic components 31 that are heat sources, and allows the control unit 30 to be cooled more efficiently.

[0042] 2, in this embodiment, the cooling passage 48 is formed such that the length D1 between the partition 42 and the end on the substrate 32 side is greater than the length D2 between the partition 42 and the end on the motor unit 20 side. Specifically, in the partition 42, the axial length D1 from the cooling passage 48 to the end on the substrate 32 side is greater than the axial length D2 from the cooling passage 48 to the end on the motor unit 20 side. This makes it possible to increase the thickness of the partition 42 from the cooling passage 48 to the end on the substrate 32 side, which is the region through which the heat of the electronic component 31 is transferred, and to more efficiently cool the control unit 30. Furthermore, the electric pump 100 is attached with the shoulder surface 42d of the partition 42 in contact with the attachment target 101, so that stress is likely to act near the shoulder surface 42d when the electric pump 100 is attached or when a load is applied to the electric pump 100. However, by forming the cooling passage 48 on the motor section 20 side of the partition section 42 in this manner and ensuring a sufficient thickness in the vicinity of the shoulder surface 42d, the strength of the partition section 42 can be improved.

[0043] In addition, in this embodiment, since the partition portion 42 is formed separately from the housing body 41, the cooling passage 48 can be formed by processing the partition portion 42 alone. Therefore, the cooling passage 48 can be easily formed.

[0044] According to the above-described embodiment, the following effects are obtained.

[0045] In the electric pump 100, the partition portion 42 is formed with a cooling passage 48, and therefore the partition portion 42 is cooled by the fluid passing through the cooling passage 48, thereby cooling the control portion 30. In this manner, the control portion 30 is cooled by using the fluid sucked into the pump portion 10, thereby improving the cooling efficiency of the control portion 30. Furthermore, the axial wall 49 obstructs the flow of the fluid that flows along the outer circumferential surface of the housing 40 and is led to the suction port 45 (second suction port 45b), increasing the flow rate led to the cooling passage 48, thereby efficiently cooling the control portion 30.

[0046] Next, modified examples of this embodiment will be described. The following modified examples are also within the scope of the present invention, and it is possible to combine the configurations shown in the modified examples with the configurations described in the above embodiment, or to combine the configurations described in the different modified examples below.

[0047] <Variation 1> In the above embodiment, the cooling passage 48 is formed to extend linearly and penetrate the partition portion 42, and is formed so as not to surround the periphery of the insertion hole 42c. However, the cooling passage 48 is not limited to the above configuration as long as the cooling passage 48 is formed in the partition portion 42, the fluid to be sucked into the pump portion 10 passes through the cooling passage 48, and the partition portion 42 is formed with two openings 48a, 48b. For example, the cooling passage 48 may be formed to surround the periphery of the insertion hole 42c and to penetrate the partition portion 42 over a wide area of ​​the partition portion 42. In addition, it is not essential that the cooling passage 48 is formed to correspond to the position of the electronic component 31 of the control portion 30, or that the length between the partition portion 42 and the end of the partition portion 42 on the substrate 32 side is longer than the length between the partition portion 42 and the end of the partition portion 42 on the motor portion 20 side.

[0048] <Variation 2> In the above embodiment, the axial wall 49 (the first axial wall 49a and the second axial wall 49c) is provided as a pair so as to separate the space 70 into two. However, the axial wall 49 may be provided only with one of the first axial wall 49a and the second axial wall 49c. In this case, the axial wall 49 is formed between the two suction ports 45 in the circumferential direction and between the two openings 48a, 48b of the cooling passage 48. In this case, since the space 70 is not separated into two, the fluid that has passed through the cooling passage 48 is guided to the second suction port 45b far from the supply passage 102, and the fluid that flows from the supply passage 102 along the outer circumferential surface of the housing 40 is also guided. However, even in this modified example, the axial wall 49 obstructs the flow of the fluid that flows along the outer circumferential surface of the housing 40 and is guided to the second suction port 45b, and the flow rate guided to the cooling passage 48 increases, so that the control unit 30 can be efficiently cooled.

[0049] <Modification 3> As shown in FIG. 5, in addition to the axial wall 49, the housing 40 may further have a circumferential wall 49e formed on the outer circumferential surface of the housing body 41 and extending in the circumferential direction. The circumferential wall 49e is formed between the supply passage 102 and the first suction port 45a close to the supply passage 102, and one end of the circumferential wall 49e is formed in contact with the first axial wall 49a. A top surface 49f of the circumferential wall 49e is provided in contact with the inner circumferential surface of the large diameter portion 101b of the storage portion 101a. In this case, a raised portion 45c is formed around the first suction port 45a, and the distance between the raised portion 45c and the inner circumferential surface of the large diameter portion 101b is small. In this configuration, the circumferential wall 49e diverts the flow of fluid from the supply passage 102 to the first suction port 45a and provides resistance to the flow, as shown by the arrow D. Therefore, the flow rate guided to the first suction port 45a close to the supply passage 102 is reduced, and a large flow rate can be guided to the cooling passage 48 and the second suction port 45b far from the supply passage 102. This makes it possible to efficiently cool the control unit 30. Note that a configuration may also be adopted in which the circumferential wall 49e is formed between the first axial wall 49a and the second axial wall 49c, and the fluid is guided from the supply passage 102 to the first suction port 45a through a notch formed in the circumferential wall 49e.

[0050] <Variation 4> In the above embodiment, the axial wall 49 is provided in contact with the inner circumferential surface of the large diameter portion 101b of the housing portion 101a and the step portion 101d. However, the axial wall 49 does not necessarily need to be in contact with the inner circumferential surface of the large diameter portion 101b of the housing portion 101a and the step portion 101d, and may be provided with a gap therebetween.

[0051] <Variation 5> As shown in FIG. 6, a flow rate adjusting portion may be formed in the axial wall 49. Specifically, a notch 49g may be formed in the axial wall 49 as the flow rate adjusting portion, and the fluid may be guided to the second suction port 45b far from the supply passage 102 through the notch 49g. In this configuration, the fluid is guided to the second suction port 45b through notch 49g as well as through the cooling passage 48, so that the flow rate guided to the second suction port 45b can be controlled by adjusting the shape (size) of the notch 49g. Therefore, it is possible to prevent a malfunction of the electric pump 100 due to a small flow rate guided to the second suction port 45b. Note that the flow rate adjusting portion is not limited to the notch 49g, and may be a through hole formed penetrating the axial wall 49 or a gap formed between the axial wall 49 and the accommodation portion 101a as in the above-mentioned modified example 4.

[0052] <Variation 6> In the above embodiment, the partition portion 42 is formed separately from the housing main body 41. However, the present invention is not limited to this, and the partition portion 42 may be formed integrally with the housing main body 41. Even with this configuration, the same effects as those of the above embodiment are achieved.

[0053] <Variation 7> In the above embodiment, the pump unit 10 is a vane pump. However, the pump unit 10 may be another pump such as a gear pump. In this case, the housing 40 has one suction port 45, and the two openings 48a, 48b of the cooling passage 48 are separated by a pair of axial walls 49. Even in this configuration, the space 70 is separated into two by the axial wall 49, and the fluid is guided from one space 70 to the other space 70 through the cooling passage 48, so that the flow rate guided to the cooling passage 48 is increased, and the control unit 30 can be efficiently cooled. In this case, it is preferable that the suction port 45 is provided in the second space 70b that does not communicate with the supply passage 102 so that the flow rate guided to the cooling passage 48 is increased. Furthermore, even when only one of the first axial wall 49a and the second axial wall 49c is provided as in the above-mentioned modified example 2, the flow of the fluid that flows along the outer circumferential surface of the housing 40 and is guided to the suction port 45 is obstructed by the axial wall 49, increasing the flow rate guided to the cooling passage 48, thereby efficiently cooling the control unit 30. In this case, it is preferable that the suction port 45 is provided at a position away from the supply passage 102 so that the flow rate guided to the cooling passage 48 is increased.

[0054] The configuration, operation, and effects of the embodiment of the present invention will be described below.

[0055] The electric pump unit 105 includes an electric pump 100, a mounting body 101 having an accommodation portion 101a in which the electric pump 100 is accommodated, and a space 70 formed between the electric pump 100 and the accommodation portion 101a through which a fluid flows. The electric pump 100 includes a pump portion 10 that discharges a fluid, a motor portion 20 that drives the pump portion 10 by rotating a drive shaft 1, a control portion 30 that controls the motor portion 20, and a housing 40 that accommodates the pump portion 10, the motor portion 20, and the control portion 30. The housing 40 distributes the fluid in the space 70. The housing 40 has an intake port 45 that introduces fluid to the pump section 10, an axial wall 49 that protrudes from the outer peripheral surface of the housing 40 and extends in the axial direction of the drive shaft 1, and a partition section 42 that separates the motor section 20 and the control section 30. The partition section 42 is formed with a cooling passage 48 that is formed through the partition section 42 and through which the fluid sucked into the pump section 10 passes, and two openings 48a, 48b that are the inlet and outlet of the cooling passage 48. The axial wall 49 is formed between the two openings 48a, 48b of the cooling passage 48 in the circumferential direction of the drive shaft 1.

[0056] In this configuration, heat generated in the electronic components 31 of the control unit 30 when the electric pump 100 is driven is transferred to the partition 42. Since the partition 42 has a cooling passage 48 formed therein, the partition 42 is cooled by the fluid passing through the cooling passage 48, thereby cooling the control unit 30. In this manner, the control unit 30 is cooled by using the fluid sucked into the pump unit 10, thereby improving the cooling efficiency of the control unit 30. Furthermore, the axial wall 49 obstructs the flow of the fluid that flows along the outer circumferential surface of the housing 40 and is guided to the suction port 45, increasing the flow rate of the fluid guided to the cooling passage 48, thereby allowing the control unit 30 to be efficiently cooled.

[0057] In addition, in the electric pump unit 105, a pair of axial walls 49 are provided so as to be spaced apart in the circumferential direction and separate the space 70 into two, and the pair of axial walls 49 separate the two openings 48a, 48b of the cooling passage 48.

[0058] In this configuration, the space 70 is divided into two by the axial wall 49, and therefore the fluid is guided from one space 70 to the other space 70 through the cooling passage 48. Therefore, the flow rate guided to the cooling passage 48 is increased, and the control unit 30 can be cooled efficiently.

[0059] In addition, in the electric pump unit 105, the housing 40 has two suction ports 45, and the mounting body 101 is formed with a supply passage 102 that communicates with the space 70 and supplies fluid to the space 70, and the axial wall 49 further has a circumferential wall 49e that is formed between the supply passage 102 and the suction port 45 close to the supply passage 102 and extends in the circumferential direction of the drive shaft 1, and the circumferential wall 49e provides resistance to the flow of fluid from the supply passage 102 to the suction port 45a close to the supply passage 102.

[0060] In this configuration, resistance is applied to the fluid guided to the suction port 45a close to the supply passage 102, thereby increasing the flow rate guided to the cooling passage 48 and the suction port 45b far from the supply passage 102, thereby efficiently cooling the control unit 30.

[0061] In addition, in the electric pump unit 105, the housing 40 has two suction ports 45, and the mounting body 101 has a supply passage 102 formed therein that communicates with the space 70 and supplies fluid to the space 70, and a flow rate adjustment portion (notch 49g) is formed in the axial wall 49 or between the axial wall 49 and the accommodating portion 101a, and the fluid is guided through the flow rate adjustment portion to the suction port 45b that is far from the supply passage 102.

[0062] In this configuration, the fluid is guided to suction port 45b not only through cooling passage 48 but also through the flow rate adjustment portion, so that the flow rate guided to suction port 45b can be controlled by adjusting the shape of the flow rate adjustment portion.

[0063] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above-mentioned embodiments. [Explanation of symbols]

[0064] 1...drive shaft, 10...pump section, 20...motor section, 30...control section, 40...housing, 42...partition section, 45a...first suction port (suction port), 45b...second suction port (suction port), 48...cooling passage, 48a...first opening (opening), 48b...second opening (opening), 49...axial wall, 49a...first axial wall (axial wall), 49c...second axial wall (axial wall), 49e...circumferential wall, 49g...notch (flow rate adjustment section), 70a...first space (space), 70b...second space (space), 100...electric pump, 101...mounted body, 101a...accommodating section, 102...supply passage, 105...electric pump unit

Claims

1. An electric pump unit, An electric pump, a mounting body having a housing portion in which the electric pump is housed; a space formed between the electric pump and the housing portion through which a fluid flows, The electric pump is A pump unit that discharges a fluid; a motor unit that rotates a drive shaft to drive the pump unit; A control unit that controls the motor unit; a housing that accommodates the pump unit, the motor unit, and the control unit, The housing includes: a suction port that introduces the fluid in the space to the pump section; an axial wall protruding from an outer circumferential surface of the housing and extending in an axial direction of the drive shaft; A partition portion that separates the motor portion and the control portion, The partition portion is formed with a cooling passage formed to penetrate the partition portion and through which a fluid to be sucked into the pump portion passes, and two openings serving as an inlet and an outlet of the cooling passage are formed, The electric pump unit according to claim 1, wherein the axial wall is formed between the two openings of the cooling passage in the circumferential direction of the drive shaft.

2. 2. The electric pump unit according to claim 1, The electric pump unit is characterized in that a pair of axial walls are provided at intervals in the circumferential direction to separate the space into two, and the pair of axial walls separate the two openings of the cooling passage.

3. 2. The electric pump unit according to claim 1, The housing has two of the suction ports, a supply passage is formed in the mounting body to communicate with the space and supply a fluid to the space; The housing further includes a circumferential wall formed between the supply passage and the suction port close to the supply passage and extending in a circumferential direction of the drive shaft, The electric pump unit according to claim 1, wherein the circumferential wall provides resistance to a flow of fluid from the supply passage to the suction port close to the supply passage.

4. 2. The electric pump unit according to claim 1, The housing has two of the suction ports, a supply passage communicating with the space and supplying a fluid to the space is formed in the mounting body; An electric pump unit characterized in that a flow rate adjustment portion is formed on the axial wall or between the axial wall and the accommodating portion, and fluid is guided through the flow rate adjustment portion to the suction port far from the supply passage.

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