Electric oil pump

Abstract

An electric oil pump (1) has a pump portion (2) that generates hydraulic pressure, a motor portion (3) that drives the pump portion, a substrate (4) in which a control circuit that controls the motor portion (3) is formed by a plurality of electronic components (41), and a housing (5) that has a pump housing portion (53) that houses the pump portion, a motor housing portion (54) that houses the motor portion, and a substrate housing portion (55) that houses the substrate. The substrate (4) is arranged in a tangential direction of a circle that has an axis of the motor portion (3) as a center. The pump housing portion (53), the motor housing portion (54), and the substrate housing portion (55) are integrally formed.

Description

Technical Field

[0001] This invention relates to electric oil pumps. Background Technology

[0002] In recent years, electric oil pumps have sometimes been used in automobiles and other vehicles to supply oil to various parts of the vehicle. For example, in vehicles with an idle stop mechanism (a mechanism that automatically stops the engine when the vehicle is parked) or hybrid vehicles, an electric oil pump is sometimes installed on the transmission housing in order to maintain hydraulic pressure inside the transmission when the vehicle is parked. As such an electric oil pump, for example, the electric oil pump disclosed in Patent Document 1 is known.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-105601

[0006] Patent Document 2: Japanese Patent Application Publication No. 2017-184542

[0007] Patent Document 3: Japanese Patent Application Publication No. 2020-195196 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, in the electric oil pump described in Patent Document 1, since the substrate on which the control circuit for controlling the motor is formed is positioned perpendicular to the output shaft, the thickness of the electric oil pump in this perpendicular direction is increased. Therefore, it is expected that this increased size will be constrained by the installation space, making the installation of the electric oil pump difficult. In addition, since the pump section, motor section, and housing for housing the substrate are divided in multiple places, and these divisions are threaded together to form the housing, concerns remain regarding the strength and rigidity of the housing, resulting in insufficient reliability.

[0010] Therefore, the object of the present invention is to provide a compact electric oil pump with high reliability.

[0011] Methods for solving problems

[0012] To address the above-mentioned problems, the present invention provides an electric hydraulic pump comprising: a pump section that generates hydraulic pressure; a motor section that drives the pump section; a substrate comprising a control circuit formed by a plurality of electronic components for controlling the motor section; and a housing having a pump housing section for housing the pump section, a motor housing section for housing the motor section, and a substrate housing section for housing the substrate. The invention is characterized in that the substrate is arranged along a tangent direction to a circle centered on the axis of the motor section, and the pump housing section, the motor housing section, and the substrate housing section are integrally formed.

[0013] In this way, by arranging the substrate along the tangential direction of a circle centered on the axis of the motor section, compared to existing products where the substrate is arranged perpendicular to the axis, miniaturization or thinning of the electric oil pump can be achieved in the radial direction (particularly the thickness direction of the substrate in this invention). Furthermore, since the pump housing, motor housing, and substrate housing are integrally formed, a housing with high strength and rigidity can be provided. Therefore, a compact and highly reliable electric oil pump can be provided.

[0014] Preferably, the housing has a housing body integrally formed with a pump housing, a motor housing, and a base plate housing. An oil suction hole and a discharge hole are provided on the surface of the housing body. An oil suction side flow path and a oil discharge side flow path are provided on the housing body. The oil suction side flow path connects the suction hole and the pump unit, and the oil discharge side flow path connects the discharge hole and the pump unit.

[0015] Therefore, the housing body can be cooled by the oil flowing in the suction side oil flow path and the discharge side oil flow path. This cooling effect promotes the cooling of the motor section and the base plate, which are heat sources, and improves the reliability of the electric oil pump. In addition, compared with the case where the suction side oil flow path and the discharge side oil flow path are provided as separate components from the housing body, the electric oil pump can be miniaturized.

[0016] In this electric oil pump, it is preferable to position at least one of the suction port and the discharge port between the pump section and the motor section. This ensures that sufficient space is available for the oil flow path to that port without considering interference with components housed within the housing.

[0017] Since the outer diameter of the bearing and seal located between the pump section and the motor section is smaller than the outer diameter of each of the pump section and the motor section, as described above, by making the oil flow path to the other side pass through the outer diameter side of the bearing and seal, the space for the oil flow path can be ensured, thereby avoiding the need for a large housing.

[0018] Preferably, the housing body is formed of a conductive metallic material. Thus, the substrate is covered by a substrate housing portion made of conductor. Therefore, the electromagnetic sensitivity (immunity) of the substrate can be reduced, and the reduction in control accuracy of the motor unit caused by electromagnetic noise can be avoided, thereby improving the reliability of the electric oil pump.

[0019] Preferably, the pump section and the motor section are arranged axially, and the substrate is configured to span the pump section and the motor section.

[0020] Therefore, sufficient substrate length can be ensured in the axial direction. Consequently, the protrusion width of the substrate relative to the motor section in the tangential direction, as already described, can be reduced, enabling miniaturization of the electric oil pump.

[0021] Preferably, the outer peripheral surface of the pump housing and the outer peripheral surface of the motor housing are provided on the bottom surface of the substrate housing, and the outer peripheral surface of the pump housing is configured to be closer to the axis of the motor housing than the outer peripheral surface of the motor housing.

[0022] Therefore, the area opposite the pump housing in the radial direction can be utilized as a space for high-height components, which are taller than the electronic components of the substrate. In this case, low-height components, which are shorter than the motor housing, can be concentrated in the area of ​​the substrate opposite the motor housing in the radial direction. As a result, the substrate can be positioned close to the bottom surface of the substrate housing. Therefore, miniaturization of the electric oil pump can be achieved in the direction perpendicular to the substrate (the thickness direction of the substrate).

[0023] To achieve this effect, it is preferable that the outer diameter of the pump section is smaller than that of the motor section.

[0024] The substrate has a high-height component and a low-height component with a height lower than the high-height component as electronic components. Preferably, the high-height component is arranged facing the outer peripheral surface of the pump housing.

[0025] Preferably, the center of the substrate in the tangential direction, as described above, is offset from the axis of the motor section in that tangential direction. This further increases the distance from one end of the substrate in the tangential direction to the outer peripheral surface of the motor housing. Consequently, sufficient space for high-height components can be reliably ensured at one end of the substrate in the tangential direction.

[0026] An opening is provided in the substrate storage section. Additionally, the electric oil pump has a closing section that seals the opening of the substrate storage section. In this case, by placing a heat dissipation member between the substrate and the closing section, heat from the high-temperature electronic components on the substrate can be efficiently released to the closing section and then to the housing body via the heat dissipation member.

[0027] By configuring the enclosed portion to contact the outside air, the above-mentioned heat dissipation path includes an enclosed portion that contacts the outside air, thus achieving a cooling effect based on the outside air.

[0028] As an electric fluid pump installed in vehicles, for example, there is an electric oil pump that maintains hydraulic pressure in the transmission when the vehicle is parked in a vehicle with an idle stop mechanism (a mechanism that automatically stops the engine when the vehicle is parked).

[0029] In this type of electric fluid pump, a board (control board) is provided with various electronic components such as capacitors for controlling fluid pressure. When current flows through the electronic components on the board, the electronic components heat up. Due to the effect of this heating, the efficiency of circuit operation may decrease, or the electronic components may be damaged.

[0030] Therefore, in Patent Document 2 above and Patent Document 3 below, a structure having a heat sink is disclosed as a heat dissipation component for dissipating heat from electronic components and a substrate. By using a heat sink to dissipate heat from electronic components on the substrate, it is possible to avoid functional degradation or damage to electronic components due to rising temperatures.

[0031] However, in addition to the above-mentioned measures of adding heat dissipation components such as heat sinks, there is also the issue of having to make design changes such as component configuration.

[0032] In order to provide an electric fluid pump that can effectively dissipate heat from a substrate without adding heat dissipation components, the electric fluid pump of the present invention comprises: a pump section for transporting fluid; a motor section for driving the pump section; a substrate having a control circuit for controlling the motor section; and a housing having a pump housing section for housing the pump section, a motor housing section for housing the motor section, and a substrate housing section for housing the substrate, characterized in that the pump housing section, the motor housing section, and the substrate housing section are integral metal components.

[0033] Thus, in this invention, since the pump housing, motor housing, and substrate housing are all integral metal components, the heat transfer of the housing is improved, enabling effective heat dissipation from the substrate through the housing. Furthermore, since no additional heat dissipation components are required, significant design changes can be avoided.

[0034] Preferably, the substrate contacts the housing via a metal foil on the substrate. In this case, the thermal conductivity from the substrate to the housing is improved, thus improving the heat dissipation of the substrate.

[0035] Alternatively, it is preferable that the substrate is fixed to the housing by a metal fastener. In this case, the thermal conductivity from the substrate to the housing is also improved, thus improving the heat dissipation of the substrate.

[0036] Furthermore, it is preferable that the substrate and the housing are in contact on the surface of the substrate on the pump housing side. As a result, the heat transfer path from the substrate to the pump housing is shortened, thus facilitating the transfer of heat from the substrate to the fluid within the pump housing, further improving the heat dissipation of the substrate.

[0037] Furthermore, it is preferable that, in the case where the housing has multiple substrate mounting portions for mounting the substrate, a portion of the substrate mounting portions is positioned closer to the pump receiving portion than the other substrate mounting portions. In this case, the heat transfer path via the substrate mounting portions on the pump receiving portion side is shortened, thus facilitating the transfer of heat from the substrate to the pump receiving portion.

[0038] Furthermore, it is preferable that the substrate is arranged along the tangential direction of a circle centered on the axis of the motor section. In this case, miniaturization (thinning) of the electro-fluid pump can be achieved in the direction perpendicular to the substrate, and since the heat transfer path from the substrate to the pump housing is shortened, it is easier to transfer heat from the substrate to the pump housing.

[0039] Based on the above structure, heat dissipation of the substrate can be effectively achieved without adding additional heat dissipation components.

[0040] Invention Effects

[0041] As described above, according to the present invention, a compact electric oil pump with high reliability can be provided. Attached Figure Description

[0042] Figure 1 This is an axial sectional view of the electric oil pump of this embodiment.

[0043] Figure 2 It is shown Figure 1 A sectional view of section II-II in the diagram.

[0044] Figure 3 It is shown Figure 1 A sectional view of section III-III in the diagram.

[0045] Figure 4 This is a top view of the substrate as seen from the mounting side.

[0046] Figure 5 This is a perspective view of the electric oil pump of this embodiment.

[0047] Figure 6 It is Figure 1 A section of the cross-sectional view is shown in enlarged form.

[0048] Figure 7 From Figure 4 A side view of the substrate viewed from direction VII.

[0049] Figure 8This is an axial sectional view of an electric oil pump according to another embodiment of the present invention.

[0050] Figure 9 It is shown Figure 8 A sectional view of the section along line IX-IX.

[0051] Figure 10 It is shown Figure 8 The sectional view of section XX in the image.

[0052] Figure 11 This is a top view of the substrate as seen from the mounting side.

[0053] Figure 12 This is a perspective view of an electric oil pump according to another embodiment.

[0054] Figure 13 This is a cross-sectional view showing the mounting structure of the substrate.

[0055] Figure 14 It is Figure 8 A section of the cross-sectional view is shown in enlarged form.

[0056] Figure 15 This is a side view of the substrate viewed from the axial direction of the motor section. Detailed Implementation

[0057] The following is based on Figures 1 to 7 The embodiments of the present invention will be described.

[0058] The electric oil pump in this embodiment provides hydraulic pressure to the transmission when the engine is stopped. Oil is drawn from an oil reservoir at the bottom of the transmission housing, discharged, and then pressurized and supplied to the transmission, thereby ensuring the necessary hydraulic pressure within the transmission.

[0059] like Figures 1 to 3 As shown, the electric oil pump 1 of this embodiment includes a pump section 2 that generates hydraulic pressure, a motor section 3 that drives the pump section 2, a base plate 4, the pump section 2, the motor section 3, and a housing 5 that houses the base plate 4. Hereinafter, each component or element will be described in detail.

[0060] In the following explanation, the direction parallel to the axis O of the motor part 3 is referred to as the "axial direction," and the radial direction of the circle centered on the axis O is referred to as the "radial direction" (the "inner diameter direction" and "outer diameter direction" also refer to the inner diameter direction and outer diameter direction of the circle). In addition, the circumferential direction of the circle centered on the axis O is referred to as the "circumferential direction."

[0061] like Figure 1 and Figure 2As shown, the pump unit 2 in this embodiment is a subcycloidal pump, which includes: an inner rotor 21 having a plurality of external teeth; an outer rotor 22 having a plurality of internal teeth; and a pump housing 23, which serves as a stationary component and houses the inner rotor 21 and the outer rotor 22. The inner rotor 21 is disposed on the inner diameter side of the outer rotor 22. The outer rotor 22 is located at an eccentric position relative to the inner rotor 21. A portion of the teeth of the outer rotor 22 meshes with a portion of the teeth of the inner rotor 21. Furthermore, if the number of teeth of the inner rotor 21 is set to n, then the number of teeth of the outer rotor 22 is (n+1).

[0062] The outer circumferential surface of the outer rotor 22 and the inner circumferential surface of the pump housing 23 are both cylindrical surfaces that can fit together. The outer rotor 22 is rotatably disposed on the inner circumference of the pump housing 23 in such a way that it rotates passively in response to the rotation of the inner rotor 21.

[0063] like Figure 1 As shown, the motor unit 3 and the pump unit 2 are arranged axially. For example, a three-phase brushless DC motor is used as the motor unit 3. Figure 1 and Figure 3 As shown, the motor unit 3 includes: a stator 30 having a plurality of coils 30a; a rotor 31 disposed inside the stator 30 with a gap; and an output shaft 32 connected to the rotor 31. Coils 30a corresponding to the U-phase, V-phase, and W-phase are formed on the stator 30.

[0064] The output shaft 32 protrudes axially to both sides of the stator 30. The portions of the output shaft 32 that protrude axially from the stator 30 are supported by bearings (such as rolling bearings like deep groove ball bearings) 33 and 34, respectively, so that they can rotate relative to the housing 5.

[0065] An inner rotor 21 of the pump section 2 is mounted at the end of the output shaft 32 on the pump section 2 side. No reducer is provided between the output shaft 32 and the pump section 2; the inner rotor 21 is directly connected to the output shaft 32 of the motor section 3. A seal 35 with a sealing lip that slides in contact with the outer peripheral surface of the output shaft 32 is provided between the bearing 33 located on the axial pump section 2 side and the inner rotor 21. This seal 35 prevents oil leakage from the pump section 2 to the motor section 3. An axially compressible elastic member 36 is provided between the bearing 33 on the axial pump section 2 side and the seal 35.

[0066] To detect the rotation angle of the rotor 32 in the motor unit 3, a detection unit 37 is provided between the rotating side and the stationary side of the motor unit 3. For example... Figure 1As shown, the detection unit 37 in this embodiment can be composed of a sensor magnet 37a (e.g., a neodymium-bonded magnet) mounted on the shaft end opposite the pump section of the output shaft 32 via a bracket 38, and a magnetic sensor 37b, such as an MR element, disposed in the housing 5 which is on the stationary side. The magnetic sensor 37b is arranged opposite the shaft end opposite the pump section of the output shaft 32 and is mounted on a sub-board 39 arranged in a direction perpendicular to the output shaft 32. The detection value of the magnetic sensor 37b is input to the control circuit of the board 4 (main board) described later.

[0067] Alternatively, a Hall element can be used as the magnetic sensor 37b. Furthermore, in addition to the magnetic sensor, an optical encoder, a rotary transformer, etc., can be used as the detection unit 37. Additionally, a sensorless drive motor unit 3 can also be used.

[0068] like Figure 4 As shown, substrate 4 is rectangular when viewed from above. Figure 1 and Figure 3 As shown, the substrate 4 is arranged parallel to the output shaft 32 of the motor section 3, and the mounting surface 40 of the substrate 4 extends in the tangential direction of a circle centered on the axis O of the motor section 3. The two ends of the substrate 4 in the aforementioned tangential direction are located at positions extending in the aforementioned tangential direction from the outer peripheral contour M (outer peripheral contour of the stator) of the motor section 3.

[0069] Multiple electronic components 41 are mounted on one side of the substrate 4. For example... Figure 4 As shown, the electronic components include capacitors (electrolytic capacitors such as aluminum electrolytic capacitors) 41a, inductors 41b, semiconductor elements 41c such as MOS-FETs, and integrated circuits such as driver ICs, resistors, etc. These electronic components 41 constitute a control circuit that controls the drive of the motor unit 3. Among them, capacitors 41a and inductors 41b are relatively tall electronic components (referred to as high-height components), while semiconductor elements 41c, integrated circuits, and resistors are relatively short electronic components (referred to as low-height components). Figure 2 As shown, the substrate 4 has the surface (mounting surface) 40 on which these electronic components 41 are mounted positioned opposite the pump section 2 and the motor section 3.

[0070] Power is supplied to substrate 4 from an external power source via connector 42. The polarity of the drive current is controlled in the control circuit of substrate 4. Figure 1 As shown, the controlled current is supplied to each coil 30a of the stator 30 provided in the motor section 3 via a busbar 43 connected to the substrate 4. A heat sink 44, serving as a heat dissipation component, is mounted on the surface 42 of the substrate 4 opposite to the mounting surface 40. The heat sink 44 is formed of a material with high thermal conductivity and compressibility. The heat sink 44 is arranged in contact with high-heat-generating components (e.g., semiconductor element 41c) in the electronic components.

[0071] The housing 5 has a cylindrical housing body 50 with openings at both ends, a first cover 51 that closes the axial pump side opening of the housing body 50, and a second cover 52 that closes the axial opposite pump side opening of the housing body 50. The first cover 51 and the second cover 52 are respectively fixed to the housing body 50 using a plurality of fastening bolts B1 and B2.

[0072] The second cover 52 has: a cylindrical bearing housing 52a that supports the bearing 34 on the opposite side of the pump section; and a cover 52b that closes the opening on the opposite side of the bearing housing 52a. A sub-base plate 39 is disposed on the inner diameter side of the bearing housing 52a. The cover 52b is mounted to the bearing housing 52a using a fastening member (not shown).

[0073] The housing body 50 integrally comprises a pump housing 53 for housing the pump section 2, a motor housing 54 for housing the motor section 3, and a substrate housing 55 for housing the substrate 4. The housing body 50, the first cover 51, and the second cover 52 are formed of a conductive and thermally conductive metal material (e.g., aluminum alloy).

[0074] The pump housing 53 of the housing 5 has a generally cylindrical shape that includes the pump housing 23 of the pump section 2. A partition wall 56 is provided on the inner circumferential surface of the pump housing 53, dividing the interior of the housing into a pump section 2 side and a motor section 3 side. The inner circumferential surface of the partition wall 56 extends to a position close to the outer circumferential surface of the output shaft 32. The inner circumferential surface of the partition wall 56 is in a non-contact state with the outer circumferential surface of the output shaft 32, thereby allowing rotation of the output shaft 32.

[0075] The motor housing 54 is formed in a cylindrical shape. The stator 30 of the motor part 3 is pressed into or bonded to the inner circumferential surface of the cylindrical motor housing 54 (see reference). Figure 3 The bearing 33 and seal 35, as described above, are mounted on the inner circumferential surface of the motor housing 54 on the side of the pump section 2 closer to the axial direction than the motor section 3. The bearing 33 and seal 35 are located on the opposite side of the partition wall 56 from the axial direction of the pump section.

[0076] Figure 5 It is Figure 1 The electric oil pump 1 shown is a perspective view when viewed from the pump section 2 side and the base plate storage section 55 side, upside down. Figure 5As shown, the substrate storage portion 55 of the housing 5 has a peripheral wall 55a that is rectangular in shape when viewed from the radial direction and has an opening on the outer diameter side in the radial direction. The substrate 4 disposed within the substrate storage portion 55 is surrounded by the peripheral wall 55a. After the substrate 4 is disposed within the substrate storage portion 55, the opening of the substrate storage portion 55 is closed by a cover 57, which serves as a closure. The cover 57 is mounted to the housing body 50 using fastening members B3. The fastening members refer to all bolts, including self-tapping screws. In this state, the cover 57 and... Figure 1 The heat sink 44 is in contact with the heat sink. Thus, heat from the high-temperature electronic components 41 on the substrate 4 can be efficiently released via the heat sink 44 to the cover 57 and then to the housing body 50. Since the heat path includes the cover 57 which is in contact with the outside air, a cooling effect based on the outside gas can also be expected.

[0077] like Figure 1 As shown, the bottom surface 55b of the substrate housing 55 is formed by the outer peripheral surface of the pump housing 53 and the outer peripheral surface of the motor housing 54. In this bottom surface 55b, there is a step in the radial direction between the outer peripheral surface of the pump housing 53 and the outer peripheral surface of the motor housing 54, and the outer peripheral surface of the pump housing 53 is located closer to the axis O of the motor 3 in the radial direction than the outer peripheral surface of the motor housing 54.

[0078] like Figure 1 and Figure 5 As shown, flange-shaped mounting portions 58 and 59 for mounting the electric oil pump 1 to a mounting object (a transmission housing in this embodiment) are integrally formed on both axial sides of the housing body 50. Two fastening holes 58a are formed in the mounting portion 58 on the pump portion 3 side, and two fastening holes 59a are formed in the mounting portion 59 on the opposite side of the pump portion. A fastening component (not shown) is inserted into these fastening holes 58a and 59a, and then screwed into the mounting object, thereby mounting the electric oil pump 1 to the mounting object.

[0079] Flat mounting surfaces 58b and 59b that contact the mounted object are formed around the fastening holes 58a and 59a of the mounting portions 58 and 59. The mounting surfaces 58b and 59b are arranged on a common plane that extends in a direction perpendicular to the substrate 4 housed in the substrate housing portion 55.

[0080] like Figure 1 As shown, an oil flow path 6 connected to the pump section 2 is provided in the housing body 50. As the oil flow path 6, the suction side oil flow path 60 and the discharge side oil flow path 61 are provided separately from each other.

[0081] like Figure 2As shown, the suction-side oil flow path 60 has: a suction-side space 60a, which opens at the meshing portion of the inner rotor 21 and the outer rotor 22; a suction hole 60b, which opens on the surface of the housing body 50; and a suction-side connecting passage 60c, which connects the suction-side space 60a and the suction hole 60b. Similarly, the discharge-side oil flow path 61 has: a discharge-side space 61a, which opens at the meshing portion of the inner rotor 21 and the outer rotor 22; a discharge hole 61b, which opens on the surface of the housing body 50; and a discharge-side connecting passage 61c, which connects the discharge-side space 61a and the discharge hole 61b.

[0082] Both the suction-side space 60a and the discharge-side space 61a are located in the region opposite to the axial pump section of the pump section 3 within the pump housing 53. Both the suction-side space 60a and the discharge-side space 61a are arc-shaped extending along the circumferential direction of the output shaft 32, and are positioned opposite each other at 180° in the circumferential direction. In this embodiment, the suction-side space 60a is positioned closer to the substrate 4 than the discharge-side space 61a. Furthermore, as... Figure 5 As shown, the suction port 60b and the discharge port 61b open on the surface of the housing 5 opposite to the object being mounted. The suction port 60b and the discharge port 61b are located on the plane containing the mounting surfaces 58b and 59b of the mounting portions 58 and 59. Therefore, it is not necessary to run oil piping around the electric oil pump 1, which simplifies the peripheral structure of the electric oil pump 1.

[0083] In the electric oil pump with the above structure, the inner rotor 21 rotates by driving the motor unit 3. As the inner rotor 21 rotates, the outer rotor 22, which meshes with it, rotates accordingly, and the space between their teeth expands and contracts with the rotation. Therefore, oil accumulated in the oil reservoir inside the transmission housing is drawn into the pump unit 2 via the suction side oil flow path 60, and discharged into the transmission via the discharge side oil flow path 61.

[0084] The electric oil pump 1 of this embodiment, which has the above structure, has the following characteristics.

[0085] Since the substrate 4 is arranged along the tangent direction of the circle centered on the axis O of the motor section 3, compared with existing products that arrange the substrate in a direction perpendicular to the axis, the electric oil pump can be miniaturized (thinned) in the radial direction (in this embodiment, the thickness direction of the substrate 4). Furthermore, since there is no substrate perpendicular to the axial direction arranged at one end of the output shaft 32, the axial dimension of the electric oil pump does not increase due to the relatively high height of electronic components mounted on such a substrate, thus enabling miniaturization of the axial dimension of the electric oil pump 1. Additionally, since the pump housing 53, motor housing 54, and substrate housing 55 of the housing 5 are integrally formed, a housing 5 with high strength and rigidity can be provided. Therefore, a compact and highly reliable electric oil pump 1 can be provided.

[0086] Furthermore, by directly mounting the pump unit 2, motor unit 3, and base plate 4 in such a highly rigid housing 5 without inserting cushioning materials such as resin materials, the reliability of the electric oil pump 1 can be further improved.

[0087] Furthermore, the oil intake port 60b and the discharge port 61b are provided on the surface of the housing body 50. Additionally, the intake-side oil flow path 60 connecting the intake port 60b and the pump unit 2, and the discharge-side oil flow path 61 connecting the discharge port 61b and the pump unit 2, are both provided on the housing body 50. Therefore, the housing body 50 can be cooled using the oil flowing in the intake-side oil flow path 60 and the discharge-side oil flow path 61. This cooling effect promotes the cooling of the motor unit 3 and the base plate 4, which are heat sources, and improves the reliability of the electric oil pump 1. Furthermore, compared to the case where the intake-side oil flow path 60 and the discharge-side oil flow path 61 are provided as separate components from the housing body 50, the electric oil pump 1 can be miniaturized.

[0088] In this embodiment, the suction port 60b and the discharge port 61b are disposed between the pump section 2 and the motor section 3. More specifically, as... Figure 1 As shown, the suction port 60b and the discharge port 61b are positioned between the pump section 2 and the seal 35. Therefore, the space provided for the suction-side connecting passage 60c leading to the suction port 60b and the discharge-side connecting passage 61c leading to the discharge port 61b is ensured to prevent interference with components housed inside the housing 5.

[0089] Alternatively, without altering the structure of the suction-side oil flow path 60 and the discharge-side oil flow path 61, the suction-side oil flow path 60 can be used as the discharge-side oil flow path, and the discharge-side oil flow path 61 can be used as the suction-side oil flow path. Furthermore, besides arranging both the suction port 60b and the discharge port 61b between the pump section 2 and the motor section 3, one of them can also be arranged in a different region (e.g., the outer diameter side region of the motor section 3).

[0090] Furthermore, since the housing body 50 is formed of a conductive metal material, the substrate 4 is covered by a substrate housing portion 55 made of a conductor. Therefore, the electromagnetic sensitivity (interference immunity) of the substrate 4 can be reduced, and the reduction in control accuracy of the motor unit 3 caused by electromagnetic noise can be avoided, thereby improving the reliability of the electric oil pump 1. To achieve this effect, it is preferable that the cover 57 enclosing the substrate housing portion 55 is also formed of a conductive metal material (such as aluminum alloy). By forming the housing body 50 and the cover 57 with a metal material, the advantage of improved heat dissipation due to its good thermal conductivity can also be obtained.

[0091] Furthermore, in this embodiment, the substrate 4 is arranged to span the pump housing 53 and the motor housing 54 arranged along the axial direction, thus ensuring a sufficient substrate length in the axial direction. Therefore, the extension width of the substrate 4 relative to the motor section 3 in the tangential direction can be reduced, enabling miniaturization of the electric oil pump 1.

[0092] Furthermore, the outer peripheral surface of the pump housing 53 and the outer peripheral surface of the motor housing 54 are provided on the bottom surface 55b of the substrate housing 55, and the outer peripheral surface of the pump housing 53 is configured to be closer to the axis O of the motor housing 54 than the outer peripheral surface of the motor housing 54. Thus, as... Figure 6 As shown, the area opposite the pump housing 53 in the radial direction can be utilized as a configuration space for tall components (e.g., electrolytic capacitor 41a or inductor 41b) in the electronic components 41 of the substrate 4. In this case, low-height components (e.g., semiconductor element 41c, integrated circuit, or resistor) are concentrated in the area of ​​the substrate 4 opposite the motor housing 54 in the radial direction.

[0093] Therefore, the substrate 4 can be positioned close to the bottom surface 55b of the substrate housing 55. Consequently, the electric oil pump 1 can be miniaturized (thinned) in the direction perpendicular to the substrate 4. To achieve this effect, as follows... Figure 1 As shown, it is preferable that the outer diameter d of the pump section 2 is smaller than the outer diameter D of the motor section 3 (d < D). This means that a low-capacity type is used as the pump section, while a high-speed rotation type is used as the motor section 3. By rotating the low-capacity pump section 2 at high speed, the required pump capacity can be ensured.

[0094] Furthermore, as already explained, the substrate 4 is arranged along a tangential direction to the circle centered on the axis O of the motor unit 3. Additionally, in this tangential direction, both ends of the substrate 4 extend towards the regions on either side of the axis O of the motor unit. Therefore, as... Figure 7As shown, the distance from the end of the substrate 4 in the tangential direction to the cylindrical outer peripheral surface of the motor housing 54 is greater than that from its central portion. Therefore, the two ends of the substrate 4 in the tangential direction can be used as placement space for high-height components (electrolytic capacitor 41a or inductor 41b).

[0095] Especially in this embodiment, such as Figure 4 and Figure 7 As shown, the center P of the substrate 4 in the tangential direction is offset relative to the axis O of the motor section 3 in the tangential direction (offset width α). Therefore, the distance from one end of the substrate in the tangential direction to the outer peripheral surface of the motor housing section 54 can be further increased. As a result, sufficient space for the installation of the high-height components 41a and 41b can be reliably ensured at one end of the substrate 4 in the tangential direction.

[0096] Figure 4 An example configuration of an electronic component designed based on the above verification results is shown. Figure 4 In this configuration, a portion of the high-height components, including electrolytic capacitors 41a(1) and inductors 41b, are positioned opposite the outer peripheral surface of the pump housing 53, while the remaining electrolytic capacitors 41a(2) are positioned at one end of the substrate 4 along the aforementioned tangential direction. Thus, even when the substrate 4 is positioned close to the outer peripheral surface of the motor housing 54, all the high-height components (electrolytic capacitors and inductors) required for the control circuit can be positioned in an area with sufficient width relative to the bottom surface 55b of the substrate housing 55. This enables miniaturization of the electric oil pump 1 in the thickness direction of the substrate 4.

[0097] In the above description, an example was shown where the electronic component 41 was mounted only on the mounting surface 40, which faces the outer peripheral surface of the pump housing 53 and the outer peripheral surface of the motor housing 54, respectively. However, for the low-height component 41c, it can be mounted not only on the surface 40, but also on the surface 42 on the opposite side of the substrate 4 (see reference). Figure 7 In this case, the low-profile component 41c is configured to avoid the heat sink 44.

[0098] The following is based on Figures 8 to 15 Another embodiment of the present invention will be described.

[0099] The electric oil pump in this embodiment provides hydraulic pressure to the transmission when the engine is stopped. Oil is drawn from an oil reservoir at the bottom of the transmission housing, discharged, and then pressurized and supplied to the transmission, thereby ensuring the necessary hydraulic pressure within the transmission.

[0100] like Figures 8 to 10As shown, the electric oil pump 1 of this embodiment includes a pump section 2 that generates hydraulic pressure, a motor section 3 that drives the pump section 2, a base plate 4, the pump section 2, the motor section 3, and a housing 5 that houses the base plate 4. Hereinafter, each component or element will be described in detail.

[0101] In the following explanation, the direction parallel to the axis O of the motor part 3 is referred to as the "axial direction," and the radial direction of the circle centered on the axis O is referred to as the "radial direction" (the "inner diameter direction" and "outer diameter direction" also refer to the inner diameter direction and outer diameter direction of the circle). In addition, the circumferential direction of the circle centered on the axis O is referred to as the "circumferential direction."

[0102] like Figure 8 and Figure 9 As shown, the pump unit 2 in this embodiment is a subcycloidal pump, which includes: an inner rotor 21 having a plurality of external teeth; an outer rotor 22 having a plurality of internal teeth; and a pump housing 23, which serves as a stationary component and houses the inner rotor 21 and the outer rotor 22. The inner rotor 21 is disposed on the inner diameter side of the outer rotor 22. The outer rotor 22 is located at an eccentric position relative to the inner rotor 21. A portion of the teeth of the outer rotor 22 meshes with a portion of the teeth of the inner rotor 21. Furthermore, if the number of teeth of the inner rotor 21 is set to n, then the number of teeth of the outer rotor 22 is (n+1).

[0103] The outer circumferential surface of the outer rotor 22 and the inner circumferential surface of the pump housing 23 are both cylindrical surfaces that can fit together. The outer rotor 22 is rotatably disposed on the inner circumference of the pump housing 23 in such a way that it rotates passively in response to the rotation of the inner rotor 21.

[0104] like Figure 8 As shown, the motor unit 3 and the pump unit 2 are arranged axially. For example, a three-phase brushless DC motor is used as the motor unit 3. Figure 8 and Figure 10 As shown, the motor unit 3 includes: a stator 30 having a plurality of coils 30a; a rotor 31 disposed inside the stator 30 with a gap; and an output shaft 32 connected to the rotor 31. Coils 30a corresponding to the U-phase, V-phase, and W-phase are formed on the stator 30.

[0105] The output shaft 32 protrudes axially to both sides of the stator 30. The portions of the output shaft 32 that protrude axially from the stator 30 are supported by bearings (such as rolling bearings like deep groove ball bearings) 33 and 34, respectively, so that they can rotate relative to the housing 5.

[0106] An inner rotor 21 of the pump section 2 is mounted at the end of the output shaft 32 on the pump section 2 side. No reducer is provided between the output shaft 32 and the pump section 2; the inner rotor 21 is directly connected to the output shaft 32 of the motor section 3. A seal 35 with a sealing lip that slides in contact with the outer peripheral surface of the output shaft 32 is provided between the bearing 33 located on the axial pump section 2 side and the inner rotor 21. This seal 35 prevents oil leakage from the pump section 2 to the motor section 3. An axially compressible elastic member 36 is provided between the bearing 33 on the axial pump section 2 side and the seal 35.

[0107] To detect the rotation angle of the rotor 31 in the motor unit 3, a rotation angle detection unit 37 is provided between the rotating side and the stationary side of the motor unit 3. For example... Figure 8 As shown, the rotation angle detection unit 37 in this embodiment can be composed of a sensor magnet 37a (e.g., a neodymium-bonded magnet) mounted on the shaft end opposite the pump section of the output shaft 32 via a bracket 38, and a magnetic sensor 37b such as an MR element disposed in the housing 5 which is on the stationary side. The magnetic sensor 37b is arranged opposite the shaft end opposite the pump section of the output shaft 32 and is mounted on a sub-board 39 arranged in a direction perpendicular to the output shaft 32. The detection value of the magnetic sensor 37b is input to the control circuit of the board 4 (main board) described later.

[0108] Alternatively, a Hall element can be used as the magnetic sensor 37b. Furthermore, in addition to a magnetic sensor, an optical encoder, a rotary transformer, etc., can be used as the rotation angle detection unit 37. Additionally, a sensorless drive motor unit 3 can also be used.

[0109] like Figure 11 As shown, substrate 4 is rectangular when viewed from above. Figure 8 and Figure 10 As shown, the substrate 4 is arranged parallel to the output shaft 32 of the motor unit 3, and the mounting surface 40 of the substrate 4 extends in the tangential direction of a circle centered on the axis O of the motor unit 3 (see reference). Figure 15 The two ends of the substrate 4 in the aforementioned tangential direction are located at positions where the outer peripheral contour M (outer peripheral contour of the stator) of the motor part 3 extends outward in the aforementioned tangential direction.

[0110] Multiple electronic components 41 are mounted on one side of the substrate 4. For example... Figure 11 As shown, as an electronic component, it includes capacitors (electrolytic capacitors such as aluminum electrolytic capacitors) 41a, a CPU 41b, semiconductor elements such as MOS-FETs (inverter) 41c, and in addition, integrated circuits such as driver ICs and resistors are used. Figure 9 and Figure 10 As shown, the substrate 4 has the surface (mounting surface) 40 on which these electronic components 41 are mounted positioned opposite the pump section 2 and the motor section 3.

[0111] Power is supplied to substrate 4 from an external power source via connector 42. The polarity of the drive current is controlled in the control circuit of substrate 4. Figure 8 As shown, the controlled current is supplied to each coil 30a of the stator 30 provided in the motor section 3 via a busbar 43 connected to the substrate 4. A heat sink 44, serving as a heat dissipation component, is mounted on the surface 45 of the substrate 4 opposite to the mounting surface 40. The heat sink 44 is formed of a material with high thermal conductivity and compressibility. The heat sink 44 is arranged in contact with high-heat-generating components (e.g., semiconductor elements 41c) in the electronic components.

[0112] The housing 5 has a cylindrical housing body 50 with openings at both ends, a first cover 51 that closes the axial pump side opening of the housing body 50, and a second cover 52 that closes the axial opposite pump side opening of the housing body 50. The first cover 51 and the second cover 52 are respectively fixed to the housing body 50 using a plurality of fastening bolts B1 and B2.

[0113] The second cover 52 has: a cylindrical bearing housing 52a that supports the bearing 34 on the opposite side of the pump section; and a cover 52b that closes the opening on the opposite side of the bearing housing 52a. A sub-base plate 39 is disposed on the inner diameter side of the bearing housing 52a. The cover 52b is mounted to the bearing housing 52a using a fastening member (not shown).

[0114] The housing body 50 integrally comprises a pump housing 53 for housing the pump section 2, a motor housing 54 for housing the motor section 3, and a substrate housing 55 for housing the substrate 4. The housing body 50, the first cover 51, and the second cover 52 are formed of a conductive and thermally conductive metal material (e.g., aluminum alloy).

[0115] The pump housing 53 of the housing 5 has a generally cylindrical shape that includes the pump housing 23 of the pump section 2. A partition wall 56 is provided on the inner circumferential surface of the pump housing 53, dividing the interior of the housing into a pump section 2 side and a motor section 3 side. The inner circumferential surface of the partition wall 56 extends to a position close to the outer circumferential surface of the output shaft 32. The inner circumferential surface of the partition wall 56 is in a non-contact state with the outer circumferential surface of the output shaft 32, thereby allowing rotation of the output shaft 32.

[0116] The motor housing 54 is formed in a cylindrical shape. The stator 30 of the motor part 3 is pressed into or bonded to the inner circumferential surface of the cylindrical motor housing 54 (see reference). Figure 10 The bearing 33 and seal 35, as described above, are mounted on the inner circumferential surface of the motor housing 54 on the side of the pump section 2 closer to the axial direction than the motor section 3. The bearing 33 and seal 35 are located on the opposite side of the partition wall 56 from the axial direction of the pump section.

[0117] Figure 12 It is Figure 8The electric oil pump 1 shown is a perspective view when viewed from the pump section 2 side and the base plate storage section 55 side, upside down. Figure 12 As shown, the substrate storage portion 55 of the housing 5 has a peripheral wall 55a that is rectangular in shape when viewed from the radial direction and has an opening on the outer diameter side in the radial direction. The substrate 4 disposed within the substrate storage portion 55 is surrounded by the peripheral wall 55a. After the substrate 4 is disposed within the substrate storage portion 55, the opening of the substrate storage portion 55 is closed by a cover 57, which serves as a closure. The cover 57 is mounted to the housing body 50 using fastening members B3. The fastening members refer to all bolts, including self-tapping screws. In this state, the cover 57 and... Figure 8 The heat sink 44 is in contact with the heat sink. Thus, heat from the high-temperature electronic components 41 on the substrate 4 can be efficiently released via the heat sink 44 to the cover 57 and then to the housing body 50. Since the heat path includes the cover 57 which is in contact with the outside air, a cooling effect based on the outside gas can also be expected.

[0118] like Figure 8 As shown, the bottom surface 55b of the substrate housing 55 is formed by the outer peripheral surface of the pump housing 53 and the outer peripheral surface of the motor housing 54. In this bottom surface 55b, there is a step in the radial direction between the outer peripheral surface of the pump housing 53 and the outer peripheral surface of the motor housing 54, and the outer peripheral surface of the pump housing 53 is located closer to the axis O of the motor 3 in the radial direction than the outer peripheral surface of the motor housing 54.

[0119] like Figure 8 and Figure 12 As shown, flange-shaped mounting portions 58 and 59 for mounting the electric oil pump 1 to a mounting object (a transmission housing in this embodiment) are integrally formed on both axial sides of the housing body 50. Two fastening holes 58a are formed in the mounting portion 58 on the pump portion 2 side, and two fastening holes 59a are formed in the mounting portion 59 on the opposite side of the pump portion. A fastening component (not shown) is inserted into these fastening holes 58a and 59a, and then screwed into the mounting object, thereby mounting the electric oil pump 1 to the mounting object.

[0120] Flat mounting surfaces 58b and 59b that contact the installed object are formed around the fastening holes 58a and 59a of the mounting parts 58 and 59 (see reference). Figure 12 Mounting surfaces 58b and 59b are disposed on a common plane extending in a direction perpendicular to the substrate 4 housed in the substrate housing 55.

[0121] like Figure 8 As shown, an oil flow path 6 connected to the pump section 2 is provided in the housing body 50. As the oil flow path 6, the suction side oil flow path 60 and the discharge side oil flow path 61 are provided separately from each other.

[0122] like Figure 9 As shown, the suction-side oil flow path 60 has: a suction-side space 60a, which opens at the meshing portion of the inner rotor 21 and the outer rotor 22; a suction hole 60b, which opens on the surface of the housing body 50; and a suction-side connecting passage 60c, which connects the suction-side space 60a and the suction hole 60b. Similarly, the discharge-side oil flow path 61 has: a discharge-side space 61a, which opens at the meshing portion of the inner rotor 21 and the outer rotor 22; a discharge hole 61b, which opens on the surface of the housing body 50; and a discharge-side connecting passage 61c, which connects the discharge-side space 61a and the discharge hole 61b.

[0123] Both the suction-side space 60a and the discharge-side space 61a are located in the region opposite to the axial pump section of the pump section 2 within the pump housing 53. Both the suction-side space 60a and the discharge-side space 61a are arc-shaped extending along the circumferential direction of the output shaft 32, and are positioned 180° opposite each other in the circumferential direction. In this embodiment, the suction-side space 60a is positioned closer to the substrate 4 than the discharge-side space 61a. Furthermore, as... Figure 12 As shown, the suction port 60b and the discharge port 61b open on the surface of the housing 5 opposite to the object being mounted. The suction port 60b and the discharge port 61b are located on the plane containing the mounting surfaces 58b and 59b of the mounting portions 58 and 59. Therefore, it is not necessary to run oil piping around the electric oil pump 1, which simplifies the peripheral structure of the electric oil pump 1.

[0124] In the electric oil pump with the above structure, the inner rotor 21 rotates by driving the motor unit 3. As the inner rotor 21 rotates, the outer rotor 22, which meshes with it, rotates accordingly, and the space between their teeth expands and contracts with the rotation. Therefore, oil accumulated in the oil reservoir inside the transmission housing is drawn into the pump unit 2 via the suction side oil flow path 60, and discharged into the transmission via the discharge side oil flow path 61.

[0125] The electric oil pump of this embodiment with the above structure has the following characteristics.

[0126] As described above, in the electric oil pump of this embodiment, the housing 5 (housing body 50), which includes the pump housing 53, the motor housing 54, and the substrate housing 55, is integrally formed of an aluminum alloy with good thermal conductivity, thus improving the heat transfer performance of the housing 5. Therefore, heat from the substrate 4 and the electronic components 41 is easily transferred to the housing 5 and the oil circulating within the housing 5. Figure 8 Arrow H is used to indicate part of the path of heat transfer from substrate 4.

[0127] Thus, in this embodiment, due to the improved heat transfer from the substrate 4 to the housing 5, heat dissipation of the substrate 4 and the electronic components 41 can be effectively achieved via the housing 5. This effectively suppresses the functional degradation and damage to the electronic components 41 caused by rising temperatures, improving the reliability and durability of the electric oil pump. Furthermore, in this embodiment, heat dissipation of the substrate can be effectively achieved without adding additional heat dissipation components, thus avoiding significant design changes.

[0128] In addition, in this embodiment, such as Figure 13 As shown, the substrate 4 contacts the convex substrate mounting portion 50a provided on the housing body 50 via a metal foil (copper foil) 62 forming a circuit pattern, and is fixed by a metal fastener (screw) 63. Therefore, heat is effectively transferred from the substrate 4 to the housing 5 via these metal components (metal foil 62 and fastener 63). As a result, the heat dissipation of the substrate 4 and the electronic component 41 is improved.

[0129] In addition, in this embodiment, such as Figure 13 As shown, the substrate mounting portion 50a of the substrate 4 and the housing body 50 contacts the surface of the substrate 4 on the side of the pump receiving portion 53. Therefore, the heat transfer path from the substrate 4 to the pump receiving portion 53 is shortened, making it easier to transfer heat from the substrate 4 and the electronic component 41 to the oil in the pump receiving portion 53. Furthermore, in this embodiment, Figure 11 Two of the four substrate mounting portions 50a shown, 50a1, are located closer to the pump housing portion 53 in the direction of the motor portion 3's axis O than the other two substrate mounting portions 50a2 (see reference). Figure 13 Therefore, the heat transfer path, particularly via the substrate mounting portion 50a1 on the pump housing portion 53 side, is shortened. Thus, in this embodiment, by employing a structure that drastically shortens the heat transfer path from the substrate 4 to the pump housing portion 53, the heat from the substrate 4 can be efficiently transferred to the pump housing portion 53 and the oil inside it, effectively dissipating heat from the substrate 4 and the electronic component 41. That is, the relative temperatures of the oil, pump housing portion 53, substrate 4, and electronic component 41 are: oil temperature < pump housing portion 53 temperature < substrate 4 temperature < electronic component 41 temperature.

[0130] Furthermore, since this embodiment has the following structural features, it is possible to obtain a heat dissipation-friendly effect.

[0131] As described above, in this embodiment, since a radial step is provided on the bottom surface 55b of the substrate housing portion 55, therefore... Figure 14As shown, the area opposite the pump housing 53 in the radial direction can be utilized as a space for high-height components (e.g., electrolytic capacitor 41a) in the electronic components 41 of the substrate 4. On the other hand, low-height components (e.g., semiconductor element 41c, integrated circuit, or resistor) are concentrated in the area of ​​the substrate 4 opposite the motor housing 54 in the radial direction.

[0132] Therefore, the substrate 4 can be positioned close to the bottom surface 55b of the substrate housing 55. Consequently, the electric oil pump 1 can be miniaturized (thinned) in the direction perpendicular to the substrate 4. Since the heat transfer path from the substrate 4 to the pump housing 53 is shortened, the heat from the substrate 4 and the electronic components 41 can be effectively transferred to the oil within the pump housing 53. Furthermore, to achieve this effect, as... Figure 8 As shown, it is preferable that the outer diameter d of the pump section 2 is smaller than the outer diameter D of the motor section 3 (d < D).

[0133] In addition, in this embodiment, such as Figure 15 As shown, the substrate 4 is arranged along the tangential direction of a circle centered on the axis O of the motor section 3, thus enabling miniaturization (thinning) of the electric oil pump 1 in a direction perpendicular to the substrate 4. Furthermore, in this tangential direction, both ends of the substrate 4 (the right and left ends in the figure) extend towards the regions on either side of the axis O of the motor section. Therefore, the distance from the end of the substrate 4 in this tangential direction to the cylindrical outer peripheral surface of the motor housing section 54 is greater than that from its central portion. Therefore, the two ends of the substrate 4 in the tangential direction can be used as space for a high-profile component (electrolytic capacitor 41a).

[0134] In particular, in this embodiment, such as Figure 15 As shown, the center P of the substrate 4 in the tangential direction is offset from the axis O of the motor section 3 in the aforementioned tangential direction (offset width α). Therefore, the distance from one end of the substrate in the tangential direction to the outer peripheral surface of the motor housing 54 can be further increased. As a result, space for the electrolytic capacitor 41a, which is a high-height component, can be reliably secured at one end of the substrate 4 in the tangential direction, and it is easier to miniaturize the electric oil pump 1 in the direction perpendicular to the substrate 4. Thus, in this embodiment, since the electric oil pump 1 in the direction perpendicular to the substrate 4 can be miniaturized, the heat transfer from the substrate 4 to the pump housing 53 can be improved, and heat dissipation of the substrate 4 and the electronic components 41 can be performed more effectively.

[0135] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

[0136] In the above embodiments, the application of the present invention to an electric oil pump was described as an example, but the present invention is not limited to electric pumps that use oil. The present invention can also be applied to electric fluid pumps that deliver fluids other than oil, such as water pumps that deliver cooling water.

[0137] Label Explanation

[0138] 1: Electric oil pump; 2: Pump section; 3: Motor section; 4: Base plate (main base plate); 5: Housing; 6: Oil flow path; 21: Inner rotor; 22: Outer rotor; 30: Stator; 31: Rotor; 33: Bearing; 35: Seal; 41: Electronic components; 41a, 41b: High-height components; 41c: Low-height components; 44: Heat dissipation components (heat sink); 50: Housing body; 53: Pump housing section; 54: Motor housing section; 55: Base plate housing section; 55b: Bottom surface; 57: Sealing section (cover); 60: Suction side oil flow path; 60b: Suction port; 61: Discharge side oil flow path; 61b: Discharge port; 62: Metal foil (metal component); 63: Fixing component (metal component); O: Shaft of motor section; P: Center of base plate.

Claims

1. An electric oil pump, comprising: The pump unit generates hydraulic pressure; The motor unit drives the pump unit; A substrate having a control circuit for controlling the motor unit formed by multiple electronic components; and The housing includes a pump housing portion for housing the pump unit, a motor housing portion for housing the motor unit, and a substrate housing portion for housing the substrate. Its features are, The substrate is arranged along the tangent direction of a circle centered on the axis of the motor unit. The pump housing, the motor housing, and the substrate housing are integrally formed. The pump section and the motor section are arranged axially, and the base plate is configured to span the pump section and the motor section. The outer peripheral surface of the pump housing and the outer peripheral surface of the motor housing are provided on the bottom surface of the substrate housing. The outer peripheral surface of the pump housing is configured to be closer to the axis of the motor housing than the outer peripheral surface of the motor housing.

2. The electric oil pump according to claim 1, wherein, The housing has a housing body integrally formed with a pump housing, a motor housing, and a base plate housing. An oil intake hole and an oil discharge hole are provided on the surface of the main body of the housing. The housing body is provided with an intake-side oil flow path and an exhaust-side oil flow path. The intake-side oil flow path connects the intake port and the pump unit, and the exhaust-side oil flow path connects the exhaust port and the pump unit.

3. The electric oil pump according to claim 2, wherein, At least one of the suction port and the discharge port is disposed between the pump section and the motor section.

4. The electric oil pump according to claim 2 or 3, wherein, The main body of the shell is formed of a conductive metallic material.

5. The electric oil pump according to claim 1, wherein, The outer diameter of the pump section is smaller than that of the motor section.

6. The electric oil pump according to claim 1 or 5, wherein, The substrate has a high-height component and a low-height component with a height lower than the high-height component as electronic components. The high-height component is arranged opposite to the outer peripheral surface of the pump housing.

7. The electric oil pump according to any one of claims 1 to 3, wherein, The center of the substrate in the tangential direction is offset from the axis of the motor in the tangential direction.

8. The electric oil pump according to any one of claims 1 to 3, wherein, An opening is provided in the substrate storage section. The electric oil pump has a closure portion that seals the opening of the substrate receiving portion. A heat dissipation component is sandwiched between the substrate and the enclosure.

9. The electric oil pump according to claim 8, wherein, The enclosure is configured to be in contact with the outside air.

10. The electric oil pump according to any one of claims 1 to 3, wherein, The pump housing, the motor housing, and the substrate housing are all integral metal components.

11. The electric oil pump according to claim 10, wherein, The substrate comes into contact with the housing via a metal foil on the substrate.

12. The electric oil pump according to claim 10, wherein, The substrate is fixed to the housing by a metal fastener.

13. The electric oil pump according to claim 10, wherein, The substrate and the housing are in contact on the surface of the substrate on the side of the pump receiving portion.

14. The electric oil pump according to claim 10, wherein, The housing has multiple substrate mounting portions for mounting the substrate. A portion of the plurality of substrate mounting portions is positioned closer to the pump receiving portion than the other substrate mounting portions.

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