JP2020067034A - Electric oil pump - Google Patents

Abstract

To provide an electric oil pump 1 capable of suppressing temperature rise of a motor portion 10 without depending on a dedicated cooling device for cooling the motor 10.SOLUTION: In an electric oil pump 1 including a motor portion 10 including a motor housing 14, a pump portion 40 including a pump housing 51, a suction port 16 for sucking an oil fed from the external into the pump portion 40, and a discharge port 54 for discharging the oil in the pump portion 40 to the external, at least the suction port 16 of the suction port 16 and the discharge port 54 is formed on the motor housing 14.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electric oil pump.

  Conventionally, an electric motor having a motor part having a motor housing, a pump part having a pump housing, an inlet port for sucking oil sent from the outside into the pump part, and a discharge port for discharging the oil inside the pump part to the outside. Oil pumps are known.

  For example, the electric oil pump described in Patent Document 1 includes a suction port for sucking the oil sent from the outside into the pump unit and a discharge port for discharging the oil in the pump unit to the pump housing.

JP, 2003-278670, A

  In the electric oil pump described in Patent Document 1, there is a problem that a cooling device for cooling the motor unit is necessary in order to suppress the temperature rise of the motor unit due to energization of the coil.

  Then, the objective of this invention is providing the electric oil pump which can suppress the temperature rise of a motor part, without using the cooling device for exclusive use for cooling a motor part.

  1st exemplary invention of this application WHEREIN: The motor part provided with a motor housing, the pump part provided with a pump housing, the suction port which inhales the oil sent from the outside in the said pump part, and the oil in the said pump part. An electric oil pump having a discharge port for discharging to the outside, wherein at least one of the suction port and the discharge port is provided in the motor housing.

  According to the exemplary first invention of the present application, the temperature rise of the motor unit can be suppressed without using a dedicated cooling device for cooling the motor unit.

It is a fracture | rupture perspective view which fractures | ruptures and shows the electric oil pump which concerns on embodiment. It is a perspective view which shows the motor housing in the electric oil pump, and a part except a pump housing. It is a perspective view showing the appearance of the electric oil pump. It is a schematic diagram for demonstrating the positional relationship of each surface of the same electric oil pump. It is a side view showing the rear side of the electric oil pump of the Z-axis direction. It is a perspective view which shows the external appearance of the electric oil pump which concerns on a 1st modification. It is a side view of the electric oil pump which concerns on a 2nd modification. It is a side view of the electric oil pump which concerns on a 3rd modification.

  Hereinafter, an electric oil pump according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, an electric oil pump that supplies oil to a transmission mounted on a vehicle such as an automobile will be described. Moreover, in the following drawings, in order to make each structure easy to understand, the scale and the number of each structure may be different from the actual structure.

  Further, in the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is parallel to the axial direction of the central axis J shown in FIG. The central axis J is a central axis line of a shaft (motor shaft) 13 of the motor unit 10 described later. The Y-axis direction is parallel to the lateral direction of the electric oil pump shown in FIG. The X-axis direction is a direction orthogonal to both the Y-axis direction and the Z-axis direction.

  In the following description, the positive side (+ Z side) in the Z-axis direction will be referred to as the “rear side”, and the negative side (−Z side) in the Z-axis direction will be referred to as the “front side”. In addition, the rear side and the front side are names used merely for the purpose of description and do not limit the actual positional relationship and direction. Further, unless otherwise specified, the direction parallel to the central axis J (Z-axis direction) is simply referred to as “axial direction”, the radial direction around the central axis J is simply referred to as “radial direction”, and the central axis J The circumferential direction centered at, that is, the circumference of the central axis J (θ direction) is simply referred to as the “circumferential direction”.

  In the present specification, the term “extends in the axial direction” means, in addition to the case of strictly extending in the axial direction (Z-axis direction), the case of extending in a direction inclined by less than 45 ° with respect to the axial direction. Including. In addition, in the present specification, the phrase “extends in the radial direction” means that the term strictly extends in the radial direction, that is, the direction perpendicular to the axial direction (Z-axis direction), and in addition to the radial direction, 45 ° It also includes the case of extending in an inclined direction within the range of less than.

[Embodiment]
<Overall structure>
FIG. 1 is a perspective view showing an electric oil pump according to an embodiment, partially broken away. As shown in FIG. 1, the electric oil pump 1 according to the embodiment includes a motor unit 10, a pump unit 40, and an inverter 100. The motor unit 10 includes a shaft 13 arranged along a central axis J extending in the axial direction. The pump unit 40 is located on one axial side (rear side) of the motor unit 10 and is driven by the motor unit 10 via the shaft 13 to discharge oil. The inverter 100 is arranged on the + X side of the motor unit 10 and controls the drive of the motor unit 10.

<Motor part 10>
As shown in FIG. 1, the motor section 10 includes a shaft 13, a rotor 20, a stator 22, a motor housing 14, and a coil 22b.

  The motor unit 10 is, for example, an inner rotor type motor, in which the rotor 20 is fixed to the outer peripheral surface of the shaft 13 and the stator 22 is arranged radially outside the rotor 20. The rotor 20 is fixed to the other axial side (front side) of the shaft 13. The stator 22 is arranged to face the rotor 20.

<Pump section 40>
As shown in FIG. 1, the pump unit 40 includes a pump rotor 47 and a pump housing 51.

(Pump rotor 47)
The pump rotor 47 is attached to the rear side of the shaft 13, as shown in FIG. The pump rotor 47 includes an inner rotor 47a and an outer rotor 47b. The inner rotor 47a is fixed to the shaft 13. The outer rotor 47b surrounds the radially outer side of the inner rotor 47a.

  The inner rotor 47a has an annular shape. The inner rotor 47a is a gear having teeth on its radially outer surface. The inner rotor 47a rotates together with the shaft 13 around the axis (θ direction). In FIG. 1, a part of the outer rotor 47b is not shown in order to show a fractured surface of the outer rotor 47b. The outer rotor 47b is an annular shape that surrounds the outer side of the inner rotor 47a in the radial direction. The outer rotor 47b is a gear having teeth on its radially inner surface. The outer radial surface of the outer rotor 47b is circular.

  The gear on the radially outer side of the inner rotor 47a and the gear on the radially inner side of the outer rotor 47b mesh with each other, and the inner rotor 47a rotates as the shaft 13 rotates, whereby the outer rotor 47b rotates. That is, the rotation of the shaft 13 causes the pump rotor 47 to rotate. The motor unit 10 and the pump unit 40 are provided with a shaft 13 as a rotating shaft made of the same member. This can prevent the electric oil pump 1 from increasing in size in the axial direction.

  Further, as the inner rotor 47a and the outer rotor 47b rotate, the volume between the meshing portions of the inner rotor 47a and the outer rotor 47b changes. The region where the volume decreases is the pressurizing region, and the region where the volume increases is the negative pressure region.

(Pump cover 52)
The pump housing 51 has an opening at the rear end in the Z-axis direction. This opening is closed by the pump cover 52. The pump cover 52 is fixed to the pump housing 51 with bolts 53.

(housing)
The motor housing 14 of the motor unit 10 and the pump housing 51 of the pump unit 40 are parts of a single member. The motor housing 14 and the pump housing 51 are cast products made of metal (for example, aluminum).

  The rotor accommodating portion of the pump portion 40 that accommodates the pump rotor 47 and the motor housing 14 of the motor portion 10 may be a single member portion or separate members. Further, the motor housing 14 of the motor unit 10 and the pump housing 51 of the pump unit 40 may be separate bodies.

  When the motor housing 14 and the pump housing 51 are portions of a single member like the electric oil pump 1 according to the embodiment, the boundary between the motor housing 14 and the pump housing 51 in the Z-axis direction is as follows. Is defined as That is, the center in the Z-axis direction of the wall provided with the through hole that penetrates the shaft 13 from the inside of the motor housing 14 toward the rotor housing portion of the pump housing 51 is the boundary in the Z-axis direction of both housings.

<Inverter 100>
The inverter 100 includes an electronic board 101. The electronic board 101 includes a plurality of electronic components 101b and a board 101a on which the plurality of electronic components 101b are mounted.

  FIG. 2 is a perspective view showing a portion of the electric oil pump 1 excluding the motor housing 14 and the pump housing 51. The motor 11 shown in FIG. 2 is housed inside the motor housing 14 shown in FIG. Inside the motor cover 12 of the motor 11, the rotor 20, the stator 22, the shaft 13 and the like shown in FIG. 1 are arranged.

  The inverter 100 includes a connector 102 connected to an external connector connected to a power source, as shown in FIG.

  FIG. 3 is a perspective view showing the appearance of the electric oil pump 1. A plurality of cooling fins 60 are provided at the end of the motor housing 14 of the electric oil pump 1 in the + Y axis direction.

  A first mounting surface 23, a second mounting surface 25, a first knock pin hole 18, a first bolt hole 19, and a suction port 16 are provided on an end surface (hereinafter referred to as a side surface) of the motor housing 14 in the −Y axis direction. . The first mounting surface 23 and the second mounting surface 25 are mounting surfaces for a transmission that is a mounted body to which the electric oil pump 1 is mounted. The suction port 16 is an opening for sucking the oil sent from the transmission into the pump portion 40, and is in a state of opening in the −Y axis direction orthogonal to the Z axis direction.

  The first mounting surface 23 is provided with a first bolt hole 19 and a first knock pin hole 18. The first bolt hole 19 is a hole through which a bolt screwed into a female screw provided in the transmission is inserted. The first knock pin hole 18 is a hole into which the positioning first knock pin provided in the transmission is fitted.

  A third mounting surface 58, a third bolt hole 57, a second knock pin hole 56, and a discharge port 54 are provided on an end surface (hereinafter referred to as a side surface) of the pump housing 51 in the −Y axis direction. The discharge port 54 is an opening that discharges the oil in the pump unit 40 toward the transmission, and is in a state of opening toward the −Y axis direction that is orthogonal to the Z axis direction.

  The second mounting surface 25 is provided with a second bolt hole 24. The third mounting surface 58 is provided with a third bolt hole 57 and a second knock pin hole 56. The first knock pin of the transmission is fitted into the first knock pin hole 18, and the second knock pin of the transmission is fitted into the second knock pin hole 56, whereby the electric oil pump 1 is positioned with respect to the transmission. The electric oil pump 1 thus positioned is fixed to the transmission by the bolts inserted through the first bolt hole 19, the second bolt hole 24, and the third bolt hole 57, respectively.

  FIG. 4 is a schematic diagram for explaining the positional relationship of each surface of the electric oil pump 1. In FIG. 4, reference symbol P indicates an imaginary plane extending along the Z-axis direction. As shown, the first mounting surface 23, the second mounting surface 25, the surface 17 around the suction port 16, the surface 55 around the discharge port 54, and the third mounting surface 58 are located on the same virtual plane. To do.

  FIG. 5 is a side view showing the rear side of the electric oil pump 1 in the Z-axis direction. The motor housing 14 is provided with a suction passage 27 that allows oil to flow between the suction port 16 and the pump portion 40. An end portion of the suction passage 27 on the pump portion 40 side is provided in the pump housing 51. A passage sealing plug 26 is fitted into an opening provided on a side surface of the motor housing 14 for opening the suction passage 27. Further, as shown in FIG. 3, a passage sealing plug 26 is fitted into an opening provided on the −X side end surface of the motor housing 14 for opening the suction passage 27.

  As shown in FIG. 5, the pump housing 51 and the motor housing 14 are provided with a discharge passage 61 that allows oil to flow between the pump portion 40 and the discharge port 54. The discharge passage 61 passes from the inside of the pump housing 51 through the inside of the motor housing 14, and then returns to the inside of the pump housing 51 and reaches the discharge port 54.

  A passage sealing plug 26 is fitted into an opening provided on the side surface of the motor housing 14 for opening the discharge passage 61. Further, as shown in FIG. 3, a passage sealing plug 59 is fitted into an opening provided on the −X side end surface of the pump housing 51 for opening the discharge passage 61.

  The area of the suction port 16 shown in FIG. 5 is larger than the area of the discharge port 54. The cross-sectional area of the suction passage 27 is larger than the cross-sectional area of the discharge passage 61.

  Next, each modification in which a part of the configuration of the electric oil pump 1 according to the embodiment is modified to another configuration will be described. Unless otherwise specified below, the configuration of the electric oil pump 1 according to each modification is the same as that of the embodiment.

<First Modification>
FIG. 6 is a perspective view showing the external appearance of the electric oil pump 1 according to the first modification. In the electric oil pump 1 according to the first modification, both the suction port 16 and the discharge port 28 are provided in the motor housing 14. The discharge port 28 provided in the motor housing 14 is provided with a symbol (28) different from that of the discharge port 54 provided in the pump housing 51 as in the embodiment.

<Second Modification>
FIG. 7 is a side view of the electric oil pump 1 according to the second modification. In the electric oil pump 1 according to the second modified example, the electronic board 101 of the inverter 100 is provided in a posture extending in the Y-axis direction orthogonal to the Z-axis direction.

<Operation and effect of electric oil pump 1>
(1) The electric oil pump 1 according to the embodiment includes a motor unit 10 having a motor housing 14, a pump unit 40 having a pump housing 51, and an intake port for sucking oil sent from the outside into the pump unit 40. 16 are provided. Further, the electric oil pump 1 according to the embodiment includes the discharge port 54 that discharges the oil in the pump unit 40 to the outside. The suction port 16 is provided in the motor housing 14.

  In such a configuration, when the oil, which has been sucked from the suction port 16 of the motor housing 14 and then flows into the pump portion 40, passes through the motor housing 14, the motor portion 10 whose temperature has been raised by energizing the coil is cooled. To do. Therefore, according to the electric oil pump 1 according to the embodiment, the temperature rise of the motor unit 10 can be suppressed without using a dedicated cooling device for cooling the motor unit 10.

  Of the suction port 16 and the discharge port 54, only the discharge port 54 may be provided in the motor housing 14. With such a configuration, when the oil, which is sent from the inside of the pump unit 40 and goes to the discharge port of the motor housing 14, passes through the inside of the motor housing 14, the motor unit 10 whose temperature has risen due to the energization of the coil is cooled.

(2) In the electric oil pump 1 according to the embodiment, the suction passage 27 that allows oil to flow between the suction port 16 and the pump portion 40 is provided in the motor housing 14. According to the electric oil pump 1 having such a configuration, the motor section 10 can be cooled by the oil flowing in the suction passage 27 provided in the motor housing 14.

(3) In the electric oil pump 1 according to the embodiment, the area of the suction port 16 is larger than the area of the discharge port 54. In the electric oil pump 1 having such a configuration, since the areas of the suction port 16 and the discharge port 54 are different from each other, a pressure difference occurs between the oil sucked into the suction port 16 and the oil discharged from the discharge port 54. To do. Further, in the electric oil pump 1, when the pump section 40 operates under the condition that the required discharge pressure is obtained, the area of the suction port 16 is larger than the area of the discharge port 54, so that the areas are the same. Compared with the case, the pressure drop of the oil sucked into the suction port 16 is suppressed.

  According to the electric oil pump 1 according to the embodiment, a pressure difference is generated between the oil sucked into the suction port 16 and the oil discharged from the discharge port 54, so that an excessive amount of discharge due to the shortage of the minimum required pressure difference is generated. Can be suppressed. Further, according to the electric oil pump 1, by suppressing the pressure decrease of the oil sucked into the suction port 16, it is possible to suppress the occurrence of cavitation (bubbles in the oil) due to the pressure decrease.

(4) In the electric oil pump 1 according to the first modified example, both the suction port 16 and the discharge port 28 are provided in the motor housing 14. Further, in the electric oil pump 1 according to the first modified example, the oil is circulated between the suction passage 27 and the pump portion 40, and the discharge passage 28 for circulating the oil between the suction port 16 and the pump portion 40. A discharge passage is provided in the motor housing 14. According to the electric oil pump 1 having such a configuration, the oil flowing in the suction passage 27 and the oil flowing in the discharge passage are made to function as a coolant for cooling the motor unit 10, and the motor unit 10 can be cooled efficiently. it can.

(5) In the electric oil pump 1 according to the first modified example, the area of the suction port 16 is larger than the area of the discharge port 28, and the cross-sectional area of the suction passage 27 is larger than the cross-sectional area of the discharge passage. In the electric oil pump 1 having such a configuration, the suction port 16 and the discharge port 28 have different areas, and the suction passage 27 and the discharge passage have different cross-sectional areas. A pressure difference occurs between the oil and the oil discharged from the discharge port 28. Further, in the electric oil pump 1, when the pump portion 40 operates under the condition that the required discharge pressure is obtained, the area of the suction port 16 is larger than the area of the discharge port 28 and the cross-sectional area of the suction passage 27 is the discharge passage. Since it is larger than the cross-sectional area, the pressure drop of the sucked oil is suppressed.

  According to the electric oil pump 1 according to the first modification, a pressure difference is generated between the oil sucked into the suction port 16 and the oil discharged from the discharge port 28, so that the excessive amount of discharge due to the shortage of the minimum required pressure difference is prevented. Occurrence can be suppressed. Further, according to the electric oil pump 1, by suppressing the pressure decrease of the oil sucked into the suction port 16, it is possible to suppress the occurrence of cavitation due to the pressure decrease.

(6) In the electric oil pump 1 according to the embodiment, the mounting surface (23, 25, 58) for the transmission to which the electric oil pump 1 is attached is provided in the motor housing 14. In the electric oil pump 1 having such a configuration, the electric oil pump 1 is generally provided with the attachment surface on the motor portion 10 which is heavier than the pump portion 40, so that the electric oil pump 1 is provided with a transmission surface more than when the attachment portion is provided on the pump portion 40. It is firmly fixed to. According to the electric oil pump 1 that is firmly fixed in this way, it is possible to improve the vibration resistance of the electric oil pump 1 due to disturbance, as compared with the configuration in which the mounting surface is provided on the pump portion 40.

(7) In the electric oil pump 1 according to the embodiment, the surface 17 around the suction port 16, the surface 55 around the discharge port 54, and the mounting surface (23, 25, 58) of the motor unit 10 are the same. It is located on the same virtual plane P extending along the axial direction of the shaft 13.

  In the electric oil pump 1 having such a configuration, when the electric oil pump 1 is attached in a state where the attachment surface (23, 25, 58) is in close contact with the attachment surface of the transmission, the surface 17 around the suction port 16 and the discharge surface The surface 55 around the outlet 54 is in close contact with the mounting surface of the transmission to seal the suction port 16 and the discharge port 54. That is, in the electric oil pump 1, the suction port 16 and the discharge port 54 are sealed as the electric oil pump 1 is attached to the transmission. At this time, the electric oil pump 1 is fixed to the transmission in a posture in which the Y-axis direction extends in the direction orthogonal to the mounting surface of the transmission. In the electric oil pump 1 fixed as described above, compared with the structure in which the electric oil pump 1 is fixed to the transmission in a posture in which the Z direction is extended in the direction orthogonal to the mounting surface of the transmission, the end surface opposite to the mounting surface and the mounting surface are mounted. The distance to the surface becomes shorter. Therefore, the vibration force applied to the electric oil pump 1 is further reduced by the lever principle, with the mounted surface of the transmission as the fulcrum and the portion opposite to the mounting surface as the force point.

  According to the electric oil pump 1 according to the embodiment, since the suction port 16 and the discharge port 54 can be sealed as the electric oil pump 1 is attached to the transmission, the workability of attaching the electric oil pump 1 is improved. be able to. Further, according to the electric oil pump 1, since the vibration force applied to the electric oil pump 1 fixed to the transmission is further reduced, the vibration resistance of the electric oil pump 1 due to the disturbance can be further improved. Further, according to the electric oil pump 1, since the suction port 16 and the discharge port 54 can be sealed by utilizing the force for mounting the electric oil pump 1 on the transmission, the sealing performance can be improved.

(8) In the electric oil pump 1 according to the embodiment, as shown in FIG. 1, the motor housing 14 also serves as a part of the housing of the inverter 100. According to the electric oil pump 1 having such a configuration, it is possible to save the trouble of installing the inverter 100 separately from the electric oil pump 1, and to improve the installation workability of the electric oil pump 1. Further, according to the electric oil pump 1, the motor housing 14 also serves as a part of the housing of the inverter 100, so that cost reduction and space saving can be achieved.

(9) In the electric oil pump 1 according to the embodiment, the electronic board 101 of the inverter 100 is provided so as to extend in a direction slightly inclined from the Z-axis direction. In the present invention, as described above, in addition to the case of strictly extending in the axial direction (Z-axis direction), the case of extending in the direction inclined by less than 45 ° with respect to the axial direction is also included. Therefore, in the electric oil pump 1 according to the embodiment, the electronic substrate 101 is provided in an attitude that extends in the axial direction. In the electric oil pump 1 having such a configuration, a region in the axial direction of the electric oil pump 1, that is, a region in the longitudinal direction is used as an installation space for the electronic substrate 101. According to the electric oil pump 1, the plane size of the electric oil pump 1 is increased by providing the inverter 100 by using the region in the longitudinal direction of the electric oil pump 1 as the installation space of the electronic substrate 101. Can be suppressed.

  Note that, as shown in FIG. 8 which is a side view of the electric oil pump according to the third modification, the electronic board 101 of the inverter 100 may be provided in a posture that strictly extends in the axial direction.

(10) In the electric oil pump 1 according to the second modification, the electronic board 101 of the inverter 100 is provided in a posture extending in the direction orthogonal to the axial direction. According to the electric oil pump 1 having such a configuration, as shown in FIG. 7, the inverter 100 is provided in the electric oil pump 1 without having the inverter 100 around the shaft center of the electric oil pump 1. You can

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist thereof. These embodiments and the modifications thereof are included in the scope and gist of the invention, and at the same time, included in the claimed name and its equivalent range.

1: Electric oil pump 10: Motor part 11: Motor 12: Motor cover 13: Shaft (motor shaft)
14: Motor housing 16: Suction port 17: Surface around the suction port 18: First knock pin hole 19: First bolt hole 20: Rotor 22: Stator 23: First mounting surface 24: Second bolt hole 25: Second Mounting surface 26: Passage sealing plug 27: Suction passage 28: Discharge port 40: Pump part 47: Pump rotor 47a: Inner rotor 47b: Outer rotor 51: Pump housing 52: Pump cover 53: Bolt 54: Discharge port 55: Discharge Surface around outlet 56: Second knock pin hole 57: Third bolt hole 58: Third mounting surface 59: Passage sealing plug 61: Discharge passage 100: Inverter 101: Electronic board 102: Connector J: Central axis

Claims (10)

A motor unit having a motor housing,
A pump part having a pump housing,
A suction port for sucking the oil sent from the outside into the pump section,
An electric oil pump having a discharge port for discharging the oil in the pump unit to the outside,
At least one of the suction port and the discharge port is provided in the motor housing,
Electric oil pump. A passage for allowing oil to flow between the one side and the pump portion is provided in the motor housing,
The electric oil pump according to claim 1. The area of the suction port is larger than the area of the discharge port,
The electric oil pump according to claim 1. Both the suction port and the discharge port are provided in the motor housing,
An intake passage that allows oil to flow between the suction port and the pump unit, and a discharge passage that allows oil to flow between the pump unit and the discharge port are provided in the motor housing.
The electric oil pump according to claim 1. The area of the suction port is larger than the area of the discharge port,
A cross-sectional area of the suction passage is larger than a cross-sectional area of the discharge passage,
The electric oil pump according to claim 4. An attachment surface for a pump attachment body that is an attachment target of the electric oil pump is provided in the motor housing,
The electric oil pump according to any one of claims 1 to 5. The surface around the suction port, the surface around the discharge port, and the mounting surface are located on the same virtual plane extending along the axial direction of the motor shaft of the motor unit,
The electric oil pump according to claim 6. An inverter for controlling the drive of the motor unit is provided,
The motor housing also serves as at least a part of the housing of the inverter,
The electric oil pump according to any one of claims 1 to 7. The electronic board of the inverter is provided so as to extend in the axial direction of the motor shaft of the motor unit,
The electric oil pump according to claim 8. The electronic board of the inverter is provided in a posture extending in a direction orthogonal to the axial direction of the motor shaft of the motor unit,
The electric oil pump according to claim 8.

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