Electric pump

Abstract

To improve cooling efficiency of a control unit.SOLUTION: An electric pump 100 includes: a pump part 10 configured to discharge a fluid; a motor part 20 configured to drive the pump part 10; a control unit 30 configured to control the motor part 20; and a housing 40 which houses the pump part 10, the motor part 20, and the control unit 30. The control unit 30 has a substrate 32 on which electronic components 31 are mounted. The housing 40 has a partition part 42 which separates the motor part 20 from the control unit 30. The partition part 42 is provided with a cooling passage 48 through which the fluid suctioned into the pump part 10 passes.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electric pump. [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 comprising a pump section that discharges a fluid, a motor section that drives the pump section, a control section that controls the motor section, and a housing that accommodates the pump section, the motor section, and the control section, wherein the control section has a board on which electronic components are mounted, and the housing has a partition section that separates the motor section and the control section, and the partition section has a cooling passage formed therein through which the fluid sucked into the pump section passes.

[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 control unit is cooled by using the fluid sucked into the pump unit, thereby improving the cooling efficiency of the control unit.

[0008] In addition, the present invention is characterized in that the cooling passages are formed in correspondence with the positions of the electronic components on the board.

[0009] In this invention, the control section can be cooled more efficiently by utilizing the fluid sucked into the pump section.

[0010] In the present invention, the cooling passage is formed so that the length between the partition part and the end on the substrate side is longer than the length between the partition part and the end on the motor part side.

[0011] In this invention, the control section can be cooled more efficiently by utilizing the fluid sucked into the pump section.

[0012] The present invention is also characterized in that the housing further has a housing main body portion in which the motor portion is accommodated, the partition portion is provided separately from the housing main body portion and connected to the housing main body portion, and a control portion is provided at the end of the partition portion opposite the housing main body portion.

[0013] In this invention, the cooling passage can be easily formed by processing the partition portion provided separately from the housing body. 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 showing a state in which an electric pump according to an embodiment of the present invention 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. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] An electric pump 100 according to an embodiment of the present invention will be described below with reference to the drawings. 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.

[0017] 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 also be simply referred to as the "axial direction", and the radial direction of the drive shaft 1 will also be simply referred to as the "radial direction".

[0018] 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, and a second side plate 14. The configuration and operation of the vane pump are similar to those of a well-known configuration, and therefore detailed description thereof 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.

[0019] 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 (see FIG. 2) 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, in FIG. 1, another suction port 45 is formed on the back side of the paper.

[0020] 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).

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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 that covers the opening 41a and separates the motor portion 20 and the control portion 30, a cover portion 43 connected to the partition portion 42 and covers the control portion 30, and a pump cover portion 44 that accommodates and covers the pump portion 10.

[0025] 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. In FIG. 1, only one of the suction ports 45 is shown, and another suction port 45 is formed on the rear side of the page. The suction port 45 is formed across the pump cover 44.

[0026] 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.

[0027] A cooling passage 48 (see Figs. 1 and 2) is formed in the partition section 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 section 30 and the motor section 20. The cooling passage 48 is formed so as to extend linearly and penetrate the partition section 42. The cooling passage 48 is formed to cool the control section 30, and the details of its function will be described later. An insertion hole 42c into which an end of the drive shaft 1 is inserted is formed in the partition section 42, and a bearing 51 that is provided on the outer circumferential surface of the drive shaft 1 and supports the drive shaft 1 so as to be freely rotatable is housed in the insertion hole 42c.

[0028] 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.

[0029] 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.

[0030] The mounting and fluid flow of the electric pump 100 and the function of the cooling passages 48 will now be described in detail.

[0031] Fig. 3 is a side view showing the state in which electric pump 100 is attached to a mounting body 101, and Fig. 4 is a schematic diagram showing the flow of fluid introduced into suction port 45. In Fig. 3, mounting body 101 is shown in cross section, and opening 48b of cooling passage 48 on the rear side of the paper, suction port 45b on the rear side of the paper, and the flow of fluid on the rear side of the paper (arrows B and D) are shown by dotted lines. In Fig. 4, the inner peripheral surface of mounting body 101 is shown by dotted lines.

[0032] As shown in Figs. 3 and 4, the electric pump 100 is mounted in a recessed housing portion 101a of the mounting body 101. The housing portion 101a is formed in a stepped shape having a large diameter portion 101b and a small diameter portion 101c. When the electric pump 100 is mounted on 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. In addition, the housing main body 41, the partition portion 42 on the housing main body 41 side from the shoulder surface 42d, and a part of the pump cover portion 44 are housed in the large diameter portion 101b. The large diameter portion 101b is formed with a larger diameter than the housing main 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 circumferential surface of the housing 40 and the inner circumferential surface of the large diameter portion 101b. The electric pump 100, the accommodating portion 101a, and the space 70 configure an electric pump unit 105. The space 70 communicates with a supply passage 102 formed in the mounting body 101. The space 70 is supplied with fluid that is supplied to the electric pump 100 through the supply passage 102.

[0033] 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 Figs. 3 and 4, the fluid is directly guided from the supply passage 102 to the suction port 45a close to the supply passage 102. In contrast, the fluid is guided to the suction port 45b (see Fig. 3) far from the supply passage 102 via two paths. Specifically, as shown by arrow B in Figs. 3 and 4, the fluid is guided along the outer circumferential surface of the housing 40 to the suction port 45b located on the back side of the suction port 45a. In addition, the fluid that has passed through the cooling passage 48 is also guided to the suction port 45b. More specifically, as shown by arrow C in Figs. 3 and 4, the fluid supplied from the supply passage 102 is first guided to the cooling passage 48 through an opening 48a of the cooling passage 48 close to the supply passage 102. Since the cooling passage 48 is formed to extend linearly and penetrate the partition portion 42, the fluid that passes through the cooling passage 48 is guided to the opening 48b far from the supply passage 102, and is guided to the back side of the paper in Figures 3 and 4. Then, the fluid that passes through the cooling passage 48 is guided to the suction port 45b, as shown by the arrow D in Figure 4. In this manner, the fluid is guided from the supply passage 102 to the two suction ports 45.

[0034] Here, in the electric pump 100 of this embodiment, the electronic components 31 of the control unit 30 generate heat when the pump 100 is driven. The electronic components 31 come into contact with the partition portion 42 of the housing 40, and the heat is transferred to the partition portion 42. Since the partition portion 42 has a cooling passage 48 formed therein, the partition portion 42 is cooled by the fluid passing through the cooling passage 48, thereby cooling the electronic components 31. In this way, by cooling the control unit 30 using the fluid sucked into the pump portion 10, rather than air cooling, the cooling efficiency of the control unit 30 can be improved.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] According to the above-described embodiment, the following effects are obtained.

[0039] In the electric pump 100, the partition 42 is formed with the cooling passage 48, and therefore the partition 42 is cooled by the fluid passing through the cooling passage 48, thereby cooling the control unit 30. In this manner, by cooling the control unit 30 using the fluid sucked into the pump unit 10, the cooling efficiency of the control unit 30 can be improved.

[0040] In the electric pump 100, the cooling passages 48 are formed in correspondence with the positions of the electronic components 31 on the substrate 32, so that the control unit 30 can be cooled more efficiently.

[0041] 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.

[0042] <Variation 1> In the above embodiment, the cooling passage 48 is formed so as 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 and the fluid sucked into the pump portion 10 can pass through it. For example, the cooling passage 48 may be formed so as 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. Also, a plurality of cooling passages 48 may be formed. Also, it is not essential that the cooling passage 48 is formed in correspondence with 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 greater than the length between the partition portion 42 and the end of the partition portion 42 on the motor portion 20 side.

[0043] <Variation 2> 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.

[0044] <Modification 3> In the above embodiment, the pump unit 10 is a vane pump, but the pump unit 10 is not limited to this and may be another type of pump such as a gear pump.

[0045] The configuration, operation, and effects of the embodiment of the present invention will be described below.

[0046] The electric pump 100 comprises a pump section 10 that discharges fluid, a motor section 20 that drives the pump section 10, 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. The control section 30 has a board 32 on which electronic components 31 are mounted. The housing 40 has a partition section 42 that separates the motor section 20 and the control section 30. The partition section 42 has a cooling passage 48 formed therein through which the fluid sucked into the pump section 10 passes.

[0047] 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 unit 42. Since a cooling passage 48 is formed in the partition unit 42, the partition unit 42 is cooled by the fluid passing through the cooling passage 48, thereby cooling the control unit 30. In this way, by cooling the control unit 30 using the fluid sucked into the pump unit 10, the cooling efficiency of the control unit 30 can be improved.

[0048] Moreover, in the electric pump 100 , the cooling passages 48 are formed in correspondence with the positions of the electronic components 31 on the substrate 32 .

[0049] In this configuration, the control unit 30 can be cooled more efficiently by utilizing the fluid sucked into the pump unit 10.

[0050] Furthermore, in the electric pump 100, the cooling passage 48 is formed so that the length between the end of the partition portion 42 on the substrate 32 side is longer than the length between the end of the partition portion 42 on the motor portion 20 side.

[0051] In this configuration, the control unit 30 can be cooled more efficiently by utilizing the fluid sucked into the pump unit 10.

[0052] In addition, in the electric pump 100, the housing 40 further has a housing main body portion 41 in which the motor portion 20 is accommodated, the partition portion 42 is provided separately from the housing main body portion 41 and connected to the housing main body portion 41, and the control portion 30 is provided at the end of the partition portion 42 opposite the housing main body portion 41.

[0053] In this configuration, the cooling passage 48 can be easily formed by processing the partition portion 42 provided separately from the housing body portion 41.

[0054] 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]

[0055] REFERENCE SIGNS LIST 10 pump section, 20 motor section, 30 control section, 31 electronic components, 32 circuit board, 40 housing, 41 housing main body section, 42 partition section, 48 cooling passage, 100 electric pump

Claims

1. A pump unit that discharges a fluid; A motor unit that drives 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 control unit has a substrate on which electronic components are mounted, the housing has a partition portion that separates the motor portion from the control portion, The electric pump, wherein the partition portion is formed with a cooling passage through which fluid sucked into the pump portion passes.

2. 2. The electric pump according to claim 1, The electric pump, wherein the cooling passage is formed in correspondence with the position of the electronic component on the board.

3. The electric pump according to claim 2, 13. The electric pump, comprising: a cooling passage formed such that a length between the partition portion and an end portion of the partition portion on the substrate side is greater than a length between the partition portion and an end portion of the partition portion on the motor side.

4. 2. The electric pump according to claim 1, The housing further includes a housing main body portion in which the motor portion is accommodated, the partition portion is provided separately from the housing main body and is connected to the housing main body, The electric pump, wherein the control unit is provided at an end of the partition portion opposite to the housing body portion.

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