Motor unit and drive device

Abstract

A motor unit according to one embodiment of the present invention includes a motor, an inverter, a bus bar, a motor case, and an inverter case. The inverter is electrically connected with the motor. The bus bar connects the motor and the inverter. The motor housing has a motor chamber. The inverter housing has an inverter chamber. At least a portion of the inverter chamber overlaps the motor chamber in a radial direction and an axial direction. In the motor housing and the inverter housing, a wall portion that divides the motor chamber and the inverter chamber is provided in a portion where the motor chamber and the inverter chamber overlap in the axial direction. The motor chamber and the inverter chamber communicate with each other via a communication hole through which the bus bar passes. The motor housing includes: a first housing portion that houses the bus bar; an opening portion connecting the first housing portion and the outside of the motor housing; and a pressure adjustment mechanism attached to the opening.

Description

Technical Field

[0001] The invention relates to a motor unit and a drive device.

[0002] This application claims priority based on Japanese Patent Application No. 2022-212758 filed in Japan on December 28, 2022, the contents of which are cited here. Background Art

[0003] Conventionally, in a motor unit having a motor and a housing having a motor chamber for accommodating the motor, there is known a structure in which a pressure regulating mechanism (eg, a ventilator) for ventilation with the outside of the housing is shielded by a cover (eg, see Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-115304 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, in a driving device, for example, the pressure inside the housing changes due to heat generated by a motor, etc. When a pressure difference occurs between the inside and outside of the housing, condensation may occur inside the housing.

[0009] However, in the above-mentioned conventional structure, since the pressure adjustment mechanism (breather device) is covered by the cover, there is a possibility that the pressure inside the casing cannot be adjusted.

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a motor unit and a drive device that can easily adjust the pressure of a casing.

[0011] Means for solving problems

[0012] A motor unit of one embodiment has a motor, an inverter, a bus bar, a motor housing, and an inverter housing. The motor has a rotor that can rotate around the motor axis. The inverter is electrically connected to the motor. The bus bar connects the motor and the inverter. The motor housing has a motor chamber that accommodates the motor and the bus bar. The inverter housing has an inverter chamber that accommodates the inverter. At least a portion of the inverter chamber overlaps with the motor chamber in the radial and axial directions. In the motor housing and the inverter housing, a wall portion that divides the motor chamber and the inverter chamber is provided in the portion where the motor chamber and the inverter chamber overlap in the axial direction. The motor chamber and the inverter chamber are connected via a connecting hole formed in the wall portion for the bus bar to pass through. The motor housing has: a first housing portion that accommodates the bus bar; an opening portion that connects the first housing portion and the outside of the motor housing; and a pressure adjustment mechanism that is mounted on the opening portion.

[0013] Effects of the Invention

[0014] According to one aspect of the embodiment, the pressure of the housing can be easily adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic perspective view (part 1) of the drive device according to the first embodiment as viewed from above on one axial side.

[0016] Figure 2 This is a schematic perspective view (part 2) of the drive device according to the first embodiment as viewed from above on one axial side.

[0017] Figure 3 This is a diagram (part 1) of the motor unit according to the first embodiment as viewed from one side in the axial direction.

[0018] Figure 4 This is a diagram (part 2) showing the motor unit according to the first embodiment as viewed from one side in the axial direction.

[0019] Figure 5 This is a diagram (part 1) showing the first housing portion and the pressure adjustment mechanism according to the first embodiment.

[0020] Figure 6 This is a diagram (part 2) showing the first housing portion and the pressure adjustment mechanism according to the first embodiment.

[0021] Figure 7 It is an explanatory diagram of the flow of air in the motor case according to the first embodiment.

[0022] Figure 8 This is an explanatory diagram (part 1) showing the arrangement of the pressure adjustment mechanism according to the first embodiment.

[0023] Fig. 9 This is an explanatory diagram (part 2) showing the arrangement of the pressure adjustment mechanism according to the first embodiment.

[0024] Fig.10 This is a partially enlarged view showing a wall portion surrounding the pressure adjustment mechanism in the motor case of the first embodiment.

[0025] Fig.11 This is a diagram of a motor unit according to a second embodiment as viewed from one side in the axial direction.

[0026] Fig.12 It is an explanatory diagram of the arrangement of the pressure adjustment mechanism according to the second embodiment. DETAILED DESCRIPTION

[0027] Hereinafter, the motor unit and the drive device according to the embodiment will be described in detail. Note that the present invention is not limited to the embodiment described below.

[0028] In addition, in this specification, the vertical direction is defined and described based on the positional relationship when the motor unit 10 (drive device 1) is mounted on a vehicle located on a horizontal road surface. In addition, in the drawings, a three-dimensional orthogonal coordinate system (X, Y, Z coordinate system) of X, Y, and Z is sometimes shown.

[0029] In the X, Y, Z coordinate system, the Z-axis direction is a vertical direction with the positive direction as the upper side and the negative direction as the lower side. The X-axis direction is a direction perpendicular to the Z-axis direction, and is the front-to-back direction of the vehicle equipped with the motor unit 10 (drive device 1). In an embodiment, the positive direction of the X-axis is the front side of the vehicle, and the negative direction of the X-axis is the rear side of the vehicle. The Y-axis direction is a direction perpendicular to the X-axis direction and the Z-axis direction, respectively, and is the left-to-right direction of the vehicle equipped with the motor unit 10 (drive device 1). In an embodiment, the positive direction of the Y-axis is the left side of the vehicle, and the negative direction of the Y-axis is the right side of the vehicle.

[0030] In addition, the positional relationship in the front-rear direction is not limited to the above-mentioned positional relationship, and for example, the positive direction of the X-axis is the rear side of the vehicle, and the negative direction of the X-axis is the front side of the vehicle. In this case, the positive direction of the Y-axis is the right side of the vehicle, and the negative direction of the X-axis is the left side of the vehicle.

[0031] In addition, in the drawings, a motor axis AX1 is sometimes shown as a rotation axis. The motor axis AX1 extends along the Y-axis direction, that is, the left-right direction of the vehicle. In the following description, unless otherwise specified, the direction parallel to the motor axis AX1 is referred to as the "axial direction", and the radial direction centered on the motor axis AX1 is referred to as the "radial direction". In addition, the circumferential direction centered on the motor axis AX1, that is, the direction around the motor axis AX1, is referred to as the "circumferential direction".

[0032] In addition, in this specification, "parallel" includes not only completely parallel but also approximately parallel. In addition, in this specification, "perpendicular" includes not only completely perpendicular but also approximately perpendicular.

[0033] <First embodiment>

[0034] First, refer to Figure 1 to Figure 4 The schematic configuration of the motor unit 10 and the drive device 1 according to the first embodiment will be described. Figure 1 and Figure 2 This is a schematic perspective view of the drive device 1 according to the first embodiment as viewed from above on one axial side. Figure 2 It is shown in Figure 1 The motor housing 50 is shown in a state where the cover portion 56 is removed.

[0035] Figure 3 and Figure 4This is a diagram of the motor unit 10 according to the first embodiment as viewed from one axial side I. Figure 3 and Figure 4 FIG. 5 shows a state where the cover 56 of the motor housing 50 is removed. Figure 4 Shown in Figure 3 The state of the base 42 described later is omitted.

[0036] like Figure 1 and Figure 2 As shown, the drive device 1 includes a motor unit 10 and a gear unit 70. The motor unit 10 includes a motor 20, an inverter 30, and a bus bar unit 40 (see Figure 3 ), a motor case 50, and an inverter case 60. In addition, the motor unit 10 has a cooling mechanism (not shown) and the like.

[0037] The motor 20 has a rotor 21 (see Figure 3 ) and stator 22 (refer to Figure 3 The rotor 21 is rotatable about the motor axis AX1. The other axial side T of the rotor 21 is connected to the reduction gear (not shown) of the gear unit 70. The rotation of the rotor 21 is decelerated by the reduction gear of the gear unit 70 and transmitted to the differential device (not shown).

[0038] The differential device has a drive shaft (not shown) that rotates around a differential axis AX2 that is parallel to the motor axis AX1. A vehicle axle is connected to the drive shaft. The vehicle axle rotates around the differential axis AX2.

[0039] As described above, the gear unit 70 includes a reduction gear and a differential gear. The reduction gear reduces the speed of the rotation of the rotor 21 via a plurality of gears. The differential gear transmits the reduced speed of the rotation of the rotor 21 to the wheels via the differential gears to drive the wheels. In other words, the gear unit 70 includes a plurality of gears. The gear unit 70 is housed in a gear unit housing 71 located on the other axial side T of the motor housing 50 described later.

[0040] The rotor 21 has a motor shaft 211 (see Figure 3 )、Rotor core 212 (refer to Figure 7 ) and rotor magnets (not shown).

[0041] The motor shaft 211 extends along a motor axis AX1 extending in the axial direction. The motor shaft 211 rotates around the motor axis AX1. The motor shaft 211 is a hollow shaft extending along the motor axis AX1. In addition, the motor shaft 211 is not limited to a hollow shaft, but may be a solid shaft.

[0042] The motor shaft 211 extends from the motor chamber 51 described later toward the other axial side T and protrudes toward the gear unit housing 71. The end of the motor shaft 211 protruding toward the inside of the gear unit housing 71 is connected to the gear of the gear unit 70. The motor shaft 211 is rotatably supported by the motor housing 50 via a bearing (not shown).

[0043] The rotor core 212 is formed of, for example, stacked silicon steel plates. The rotor core 212 has a through hole 212a that penetrates in the axial direction. That is, the rotor core 212 is a substantially cylindrical body extending in the axial direction. The rotor magnet is fixed to the rotor core 212. There are a plurality of rotor magnets, and in the rotor core 212, the magnetic poles are arranged alternately in the circumferential direction.

[0044] The stator 22 surrounds the rotor 21 from the radially outer side. The stator 22 has a stator core 221, a plurality of coils (not shown), and an insulator (not shown) between the stator core 221 and the coils. The stator core 221 has a plurality of magnetic pole teeth protruding radially inward from the inner circumference of a substantially annular yoke. The coil is formed by attaching a conductive wire to the magnetic pole teeth. The coil is electrically connected to the inverter 30 via a bus bar 41 described later.

[0045] The inverter 30 is electrically connected to the motor 20 via a wire harness or the like. The inverter 30 drives the motor 20. In addition, the inverter 30 is electrically connected to an oil pump or the like via a wire harness or the like.

[0046] The bus bar unit 40 connects the motor 20 and the inverter 30. Figure 3 As shown, the bus bar unit 40 includes a bus bar 41 and a base 42. The bus bar 41 is a conductor such as copper and is a long body extending in the left-right direction. In addition, the direction in which the bus bar 41 extends is not limited to the left-right direction. The bus bar 41 may be a long body extending obliquely from the left-right direction to either the upper or lower direction or to either the front or the back direction.

[0047] like Figure 4 As shown, the base 42 supports at least one bus bar 41. In the present embodiment, a plurality of bus bars 41 are supported. In the present embodiment, the base 42 is made of an insulating resin material. The base 42 supports the bus bar 41 in the motor chamber 51 of the motor housing 50. The bus bar 41 extends in the left-right direction (i.e., from the positive direction of the Y axis to the negative direction of the Y axis). The other axial side T of the bus bar 41 (see Figure 1 ) is connected to the inverter 30. The base 42 is fixed to the first housing portion by a fixing member (such as a bolt).

[0048] The motor case 50 has a motor chamber 51. The motor chamber 51 is a space formed inside the motor case 50. The motor 20 is accommodated in the motor chamber 51. In addition, the bus bar unit 40 including the bus bar 41 is accommodated in the motor chamber 51.

[0049] The inverter case 60 has an inverter chamber 61. The inverter chamber 61 is a space formed inside the inverter case 60. The inverter 30 is accommodated in the inverter chamber 61. The inverter chamber 61 is arranged above the motor chamber 51, and at least a portion of the inverter chamber 61 overlaps with the motor chamber 51 in the radial direction and the axial direction.

[0050] like Figure 4 As shown, the motor housing 50 and the inverter housing 60 have a common wall portion 52. The wall portion 52 is provided in the motor housing 50 and the inverter housing 60 at the portion where the motor chamber 51 and the inverter chamber 61 overlap in the axial direction. The wall portion 52 divides the motor chamber 51 and the inverter chamber 61 in a manner separated in the left-right direction. The portion of the wall portion 52 on the lower side in the up-down direction protrudes downwardly from the radially outer side wall constituting the motor chamber 51. The lower portion of the wall portion 52 is axially opposed to the flange portion 502 described later. That is, in the axial direction, a space is formed between the lower portion of the wall portion 52 and the flange portion 502 described later.

[0051] In addition, a communication hole 521 is formed in the wall portion 52. The motor chamber 51 and the inverter chamber 61 are communicated with each other through the communication hole 521. The bus bar 41 extending in the left-right direction passes through the communication hole 521.

[0052] like Figure 1 As shown, the motor housing 50 has a main body 501 and a flange 502. The main body 501 is in the shape of a cylinder that is open on one axial side I. In addition, although not shown in the figure, the main body 501 is in the shape of a general cylinder. A gear unit storage portion 71 is provided on the other axial side T of the main body 501. The gear unit 70 is stored in the gear unit storage portion 71. The flange 502 is provided at the end of one axial side I of the main body 501, and extends toward the radial outside of the main body 501. The radially outer end of the flange 502 protrudes radially outward from the outer surface of the main body 501.

[0053] Next, refer to Figure 5 and Figure 6 The motor case 50 according to the first embodiment will be further described. Figure 5 and Figure 6 1 is a diagram showing the first storage unit 53 and the pressure adjustment mechanism 54 of the first embodiment. Figure 5 , which is viewed from one axial side of the motor housing 50. Figure 6 2 shows a state viewed from below one side in the axial direction of the motor case 50 .

[0054] like Figure 5 and Figure 6As shown in FIG. 1 , the motor housing 50 further includes a first housing portion 53, an opening 532, and a pressure adjustment mechanism 54. The first housing portion 53 is located, for example, above the motor 20 in the motor chamber 51. The bus bar 41 (see FIG. 1 ) is housed in the first housing portion 53. Figure 4 ). In addition, the first storage portion 53 has a second storage portion 531.

[0055] The second housing portion 531 is recessed from the axial one side I toward the axial other side T in the first housing portion 53. Thus, the second housing portion 531 is a space recessed from the axial one side I toward the axial other side T.

[0056] The opening 532 is formed in the second housing portion 531 in the first housing portion 53. The opening 532 connects the second housing portion 531 and the outside of the motor case 50.

[0057] The pressure adjustment mechanism 54 adjusts the pressure difference generated inside and outside the motor housing 50. The pressure adjustment mechanism 54 releases air from the inside of the motor chamber 51 (performs ventilation). The pressure adjustment mechanism 54 is, for example, a ventilation filter. The ventilation filter is a component that has air permeability but can inhibit the passage of water, dust, etc. The pressure adjustment mechanism 54 is installed at the opening 532.

[0058] According to such a structure, the air heated by passing through the vicinity of the bus bar 41 in the first housing portion 53 among the air circulating in the motor chamber 51 is easily discharged from the pressure adjustment mechanism 54, and the pressure difference between the inside and the outside of the housing can be suppressed. In addition, since the air in the motor chamber 51 is easily ventilated, the generation of condensation inside the housing can be suppressed.

[0059] The pressure adjustment mechanism 54 is located on the outer peripheral surface of the motor housing 50. When viewed from the axial direction, the pressure adjustment mechanism 54 overlaps with the bus bar 41 in the radial direction. That is, the pressure adjustment mechanism 54 is located on the side opposite to the differential axis AX2. Therefore, for example, when the motor unit 10 is mounted on a vehicle, it is possible to prevent soil or the like rolled up by the axle of the vehicle from adhering to the pressure adjustment mechanism 54.

[0060] like Figure 6 As shown, when viewed from the radial direction, the pressure adjustment mechanism 54 is located on the axial side I of the wall 533 constituting the second housing portion 531. That is, the pressure adjustment mechanism 54 is located on the axial side I of the wall 533 constituting the front side of the second housing portion 531. The pressure adjustment mechanism 54 is provided on the side close to the motor chamber 51 in the wall 533, thereby making it easy to adjust the pressure inside and outside the housing.

[0061] In addition, when viewed from the radial direction, the pressure adjustment mechanism 54 may be located on the other axial side T of the wall 533 constituting the second housing portion. That is, the pressure adjustment mechanism 54 may be located on the other axial side T of the wall 533 constituting the front side of the second housing portion 531. The pressure adjustment mechanism 54 is provided on the side away from the motor chamber 51 in the wall 533, thereby preventing the adhering of mixed matter (contaminants) and the like inside the motor housing 50 to the pressure adjustment mechanism 54.

[0062] like Figure 3 and Figure 4 As shown, the motor unit 10 has a connector 32. The connector 32 connects the motor 20 and the inverter 30. The connector 32 connects, for example, a rotation angle sensor (e.g., a rotary transformer), a temperature sensor (e.g., a thermistor), etc. to the inverter 30. In the present embodiment, the connector 32 includes a terminal portion connected to the motor 20, etc. and a cable portion connected to the terminal. The connector 32 is connected to the inverter 30 from the motor 20 through the second storage portion 531.

[0063] Since the connector 32 passes through the second housing portion 531, interference between the connector 32 and other components can be suppressed even when the drive device vibrates. On the other hand, the first housing portion 53 has the second housing portion 531 that is recessed from the axial one side I toward the axial other side T, so that the heated air inside the motor chamber 51 easily stays inside the second housing portion 531. By arranging the pressure adjustment mechanism 54 in the second housing portion 531, the heated air inside the second housing portion 531 can be efficiently released, and the ventilation efficiency is improved.

[0064] Next, refer to Figure 7 The flow of air in the motor case 50 according to the first embodiment will be described. Figure 7 1 is an explanatory diagram of the flow of air in the motor housing 50 of the first embodiment. Figure 7 , a schematic cross section cut in a manner connecting the motor axis AX1 and the second housing portion 531 in the radial direction is shown. Figure 7 In the figure, the flow of air is indicated by arrow A.

[0065] like Figure 7As shown, the rotor 21 has the above-mentioned motor shaft 211, the above-mentioned rotor core 212, the above-mentioned rotor magnet (not shown) and the fan 213. The fan is located at the axial end of the rotor core 212. The rotor core 212 has a through hole 212a that penetrates in the axial direction. At least one vent hole 213a connected to the through hole 212a of the rotor core 212 is formed in the fan 213. When the motor 20 is driven, if the rotor 21 rotates, due to the centrifugal force accompanying the rotation of the rotor 21, the air in the through hole 212a flows to the outside of the fan 213 through the vent hole 213a. In this way, the rotor core 212 and the coil end 222 can be cooled.

[0066] On the other hand, the air coming out of the vent 213a of the fan 213 is heated by passing near the bus bar 41, the coil and other heat-generating components. The heated air flows to the second storage section 531, which is a space larger than other parts in the first storage section 53, whereby the flow rate is reduced and the air stays inside the second storage section 531. In addition, the heated air is cooled by the air outside the motor housing 50, etc., whereby condensation sometimes occurs inside the motor housing 50. However, in the present embodiment, by providing the pressure adjustment mechanism 54 in the second storage section 531, the air is easily released from the second storage section 531 to the outside of the motor housing 50.

[0067] The air remaining around the pressure regulating mechanism 54 is pushed out of the motor housing 50 from the pressure regulating mechanism 54 by the air sent in later. Thus, the heated air is discharged from the pressure regulating mechanism 54, and the ventilation efficiency is improved. Therefore, the condensation inside the motor housing 50 can be suppressed.

[0068] Next, refer to Figure 8 and Fig. 9 The arrangement of the pressure adjustment mechanism 54 according to the first embodiment will be described. Figure 8 and Fig. 9 1 is an explanatory diagram of the configuration of the pressure adjustment mechanism 54 of the first embodiment. Figure 8 5 shows a state viewed obliquely from above one axial side I of the motor housing 50. Fig. 9 2 shows a state viewed from the radial direction of the motor housing 50 .

[0069] The motor unit 10 has a cooling mechanism that uses a fluid (such as water) as a common refrigerant to cool the motor 20 and the inverter 30. The cooling mechanism cools the motor 20 and the inverter 30 using, for example, the refrigerant supplied from a radiator.

[0070] like Figure 8As shown, the motor housing 50 has a flow path 80 that allows refrigerant to flow around the stator 22. In the present embodiment, the flow path 80 is a flow path that extends in a spiral shape in the circumferential direction and the axial direction around the stator 22. The flow path 80 is provided inside the side wall located radially outside the motor housing 50. The stator 22 is fixed to the inside of the motor housing 50 (i.e., the side wall) by, for example, pressing in. That is, the inner surface of the side wall contacts the stator 22 in the radial direction. The refrigerant flows inside the flow path 80 surrounding the stator 22, thereby cooling the stator 22. In this case, the refrigerant flowing from the inverter housing 60 via a flow path such as a hose flows into the motor housing 50 from the inlet 81 of the flow path 80. The refrigerant flowing in from the inlet 81 flows in the flow path 80 and flows out to the outside of the motor housing 50 from the outlet 82 of the flow path 80.

[0071] In addition, the flow path 80 may also be an S-shaped flow path extending in the axial direction and the circumferential direction. In addition, in the present embodiment, the flow path 80 is provided inside the side wall of the motor housing 50. However, the side wall of the motor housing 50 may also be a double cylinder structure consisting of an inner cylinder portion and an outer cylinder portion, and the flow path 80 is formed between the outer side surface of the inner cylinder portion and the inner side surface of the outer cylinder portion.

[0072] One end of the flow path 80 is located on one axial side I of the motor housing 50. One end of the flow path 80 serves as, for example, an inlet 81 of the flow path 80. The other end of the flow path 80 is located on the other axial side T of the motor housing 50. The other end of the flow path 80 serves as, for example, an outlet 82 of the flow path 80. When viewed from the radial direction, one end of the flow path 80 is located at a position lower than the other end of the flow path 80 in the up-down direction. The inlet 81 of the flow path 80 is located at a position lower than the outlet 82 of the flow path 80 in the up-down direction. The inlet 81 is located at a position lower than the motor axis AX1 in the up-down direction. In the present embodiment, the direction in which the inlet 81 opens is different from the direction in which the outlet 82 opens. The inlet 81 opens toward the radially outer side. The outlet 82 opens toward the lower side in the up-down direction.

[0073] In the flow path 80, the inlet 81 may be located above the outlet 82 in the vertical direction, or may be located at the same position in the vertical direction. In addition, the direction in which the inlet 81 opens may be the same as the direction in which the outlet 82 opens.

[0074] like Figure 8As shown, the pressure adjustment mechanism 54 overlaps with the inlet 81 of the flow path 80 in the circumferential direction of the motor axis AX1. When viewed from the radial direction, the pressure adjustment mechanism 54 and the inlet 81 are arranged in the up-down direction. Around the inlet 81 for the refrigerant to flow in, the temperature difference between the inside and outside of the motor housing 50 tends to become large. However, in this embodiment, the pressure adjustment mechanism 54 overlaps with the inlet 81 in the circumferential direction, and the pressure adjustment mechanism 54 is arranged at a position where a temperature difference is likely to occur. Therefore, moisture is easily released and the ventilation efficiency is improved.

[0075] The second housing portion 531 overlaps with the inlet 81 of the flow path 80 in the circumferential direction of the motor axis AX1. When viewed from the radial direction, the second housing portion 531 and the inlet 81 are arranged in the up-down direction. When viewed from the radial direction, the second housing portion 531 is located on the upper side of the inlet 81. When viewed from the radial direction, at least a portion of the second housing portion 531 is located between one end (inlet 81) of the flow path 80 and the other end (outlet 82) of the flow path 80. Thus, when the motor unit 10 is installed in a vehicle, when an operator or an assembly device (hereinafter, an operator, etc.) approaches the pressure adjustment mechanism 54, it is possible to prevent the inlet 81 and the outlet 82 from obstructing access to the pressure adjustment mechanism 54.

[0076] Furthermore, the pressure regulating mechanism 54 overlaps with the inlet 81 of the refrigerant flow path 80 in the circumferential direction of the motor axis AX1. Thus, the pressure regulating mechanism 54 is arranged at a position where a temperature difference is likely to occur. Therefore, moisture is easily released, and ventilation efficiency is improved.

[0077] Furthermore, since the second housing portion 531 overlaps with the inlet 81 of the coolant flow path 80 in the circumferential direction of the motor axis AX1 , space can be effectively utilized, and increase in size of the motor unit 10 can be suppressed.

[0078] In addition, the inlet 81 is located at a position lower than the motor axis AX1 in the up-down direction. As described above, the lower portion of the wall portion 52 is axially opposed to the flange portion 502. That is, in the axial direction, a space is formed between the lower portion of the wall portion 52 and the flange portion 502. One end (inlet 81) of the flow path 80 described later, which is provided on the radially outer side wall of the motor housing 50 (the side wall constituting the motor chamber 51), is located in this space. That is, the inlet 81 is arranged in a space that becomes a useless space in the motor housing 50. Thus, it is possible to prevent the inlet 81 from protruding from the outer side surface of the motor housing 50, effectively utilize the useless space, and prevent the motor unit 10 from being enlarged.

[0079] Next, refer to Fig.10 The wall portion 55 formed in the motor case 50 of the first embodiment will be described. Fig.10 FIG. 2 is a partially enlarged view showing a wall portion 55 surrounding the pressure adjustment mechanism 54 in the motor housing 50 of the first embodiment. Fig.10 2 shows a state viewed from one axial side of the motor housing 50 .

[0080] like Fig.10 As shown, the motor housing 50 has a wall portion 55. The wall portion 55 protrudes radially inward from the inner side surface of the motor housing 50. The wall portion 55 protrudes radially inward from the inner peripheral surface of the second housing portion 531. The wall portion 55 surrounds at least a portion of the periphery of the pressure adjustment mechanism 54. In other words, the pressure adjustment mechanism 54 overlaps with at least a portion of the wall portion 55 in at least one direction of the radial direction and the up-down direction. In the present embodiment, the motor housing 50 has a plurality of (three in the present embodiment) wall portions 55. In the present embodiment, the wall portion 55 has three wall portions 55a, 55b, and 55c, each of which surrounds a portion of the pressure adjustment mechanism 54. A wall portion 55a closest to the pressure adjustment mechanism 54 is provided on the radial inner side of the pressure adjustment mechanism 54, and the wall portion 55a extends in a manner of surrounding a portion of the pressure adjustment mechanism 54. The wall portion 55b provided at a position closer to the inside than the wall portion 55a extends in a manner of surrounding a portion of the pressure adjustment mechanism 54. The wall portion 55c disposed at a position further inward than the wall portion 55b (i.e., disposed at a position farthest from the pressure regulating mechanism 54) extends so as to surround a portion of the pressure regulating mechanism 54. In the wall portion 55, at least a portion of each wall portion 55 is arranged alternately when viewed from the axial direction. At least a portion of each wall portion 55 overlaps each other at least in the radial direction when viewed from the axial direction. Thus, even if the refrigerant stored in the motor chamber 51 is caused by the rotor 21 (see Figure 3 ) and scatter, the refrigerant will also hit the wall portions 55, which can prevent the refrigerant and the mixed substances (contaminants) contained in the refrigerant from contacting with the pressure regulating mechanism 54. That is, the wall portion 55 can protect the pressure regulating mechanism 54.

[0081] In addition, the wall portion 55 may be formed as a continuous portion, and may be a structure surrounding the pressure adjustment mechanism 54. As in the present embodiment, a plurality of wall portions 55 may be formed, and the plurality of wall portions 55 surround the pressure adjustment mechanism 54. In this case, it is preferred that a structure (so-called labyrinth structure) in which one wall portion 55 overlaps at least a portion of the other wall portions 55 in the vertical direction. In addition, when viewed from the axial direction, the wall portion 55 may be in the shape of a rib extending in a straight line, or may be in a shape in which a portion is bent or curved.

[0082] <Second embodiment>

[0083] Next, refer to Fig.11 and Fig.12 A motor unit 10A and a drive device according to the second embodiment will be described. Fig.11 This is a diagram when viewed from one axial side I of a motor unit 10A according to the second embodiment. Fig.12It is an explanatory diagram of the arrangement of the pressure adjustment mechanism 54A according to the second embodiment.

[0084] In the second embodiment described below, the structure of the cooling mechanism (not shown) for cooling the motor housing 50 and the inverter housing 60 is different from that in the first embodiment. In addition, in the second embodiment, the structure and arrangement of the pressure adjustment mechanism 54A are different from those of the pressure adjustment mechanism 54 in the first embodiment.

[0085] In the second embodiment, the pressure adjustment mechanism 54A and the cooling mechanism are different from those in the first embodiment, and the other structures are the same as those in the first embodiment. Therefore, in the following description, the same reference numerals are given to the structures that are equal or the same as those in the first embodiment, and the description of the structures that are equal or the same as those in the first embodiment is sometimes omitted.

[0086] In the motor unit 10A of the second embodiment, by making different types of refrigerants flow inside the motor housing 50 and inside the inverter housing 60, the motor 20 and the inverter 30 can be cooled separately. A refrigerant such as water or the like, for example, antifreeze flows in the inverter housing 60. As the refrigerant flowing inside the motor housing 50, for example, oil equivalent to automatic transmission lubricating oil (ATF: Automatic Transmission Fluid) with relatively low viscosity is preferably used.

[0087] In the motor unit 10A of the second embodiment, the pressure regulating mechanism 54A is, for example, a ventilator. The ventilator can regulate the pressure inside the motor housing 50. The pressure regulating mechanism 54A is attached to an opening 532A connecting the second housing portion 531 and the outside of the motor housing 50. The opening 532A is a through hole that connects the second housing portion 531 and the outside of the motor housing 50.

[0088] like Fig.11 As shown, in the motor unit 10A of the second embodiment, the motor axis AX1, the bus bar 41 and the pressure adjustment mechanism 54A are arranged in the radial direction. The pressure adjustment mechanism 54A is located above the motor axis AX1 and is located radially inward of the outer peripheral surface 50a of the motor housing 50. The bus bar 41 covers at least a portion of the pressure adjustment mechanism 54A in the axial direction. Therefore, when a cooling mechanism is provided inside the motor chamber 51A, the bus bar 41 becomes a wall for protecting the pressure adjustment mechanism 54A, and can suppress the refrigerant such as oil from adhering to the pressure adjustment mechanism 54A.

[0089] like Fig.12As shown, the motor housing 50 has a main body 501 and a flange 502. The main body 501 is in the shape of a tube opened on one axial side I, similarly to the first embodiment described above. The flange 502 is provided at the end of one axial side I of the main body 501, similarly to the first embodiment described above, and extends toward the radially outer side of the main body 501. The radially outer end of the flange 502 protrudes radially outward from the outer surface of the main body 501. The opening 532A is a through hole that penetrates the flange 502 in the radial direction. The opening 502 is opened on the inner side and the outer side of the flange 502, respectively.

[0090] The pressure adjustment mechanism 54A is provided at the flange portion 502. That is, the pressure adjustment mechanism 54A is arranged at the opening portion 502A provided at the flange portion 502. In addition, the pressure adjustment mechanism 54A overlaps with the inverter housing 60 in the axial direction. The end face on the axial side of the flange portion 502 and the side face on the axial side of the inverter housing 60 are axially opposed. A space is provided between the end face on the axial side of the flange portion 502 and the side face on the axial side of the inverter housing 60. The pressure adjustment mechanism 54A is located in the space between the end face on the axial side of the flange portion 502 and the side face on the axial side of the inverter housing 60. Therefore, there is no need to separately ensure a space for providing the pressure adjustment mechanism 54A, thereby achieving space saving.

[0091] In addition, it is preferable that the upper end of the pressure adjustment mechanism 54A is located lower in the up-down direction than a cover (not shown) located on the upper side of the inverter case 60 .

[0092] The motor unit 10 ( 10A) and the drive device 1 of the embodiment can be used in, for example, a hybrid vehicle (HV), a plug-in hybrid vehicle (PHV), and an electric vehicle (EV).

[0093] The embodiments of the present invention are described above, but the embodiments are presented as examples and are not intended to limit the scope of the invention. The embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the subject matter of the invention. These embodiments and their variations are included in the scope and subject matter of the invention, and are also included in the invention described in the claims and their equivalents.

[0094] In addition, the present technology can adopt the following structures.

[0095] (1) A motor unit comprising: a motor having a rotor rotatable about a motor axis; an inverter electrically connected to the motor; a bus bar connecting the motor and the inverter; a motor housing having a motor chamber for accommodating the motor and the bus bar; and an inverter housing having an inverter chamber for accommodating the inverter, at least a portion of the inverter chamber overlapping with the motor chamber in radial and axial directions, wherein a wall portion for dividing the motor chamber and the inverter chamber is provided in the motor housing and the inverter housing at a portion where the motor chamber and the inverter chamber overlap in the axial direction, the motor chamber and the inverter chamber being connected via a connecting hole formed in the wall portion for allowing the bus bar to pass through, the motor housing having: a first housing portion for accommodating the bus bar; an opening portion connecting the first housing portion and the outside of the motor housing; and a pressure adjustment mechanism mounted on the opening portion.

[0096] (2) The motor unit according to (1), wherein the pressure adjustment mechanism is located on an outer peripheral surface of the motor case and overlaps with the bus bar in a radial direction when viewed from the axial direction.

[0097] (3) A motor unit according to (2), wherein the motor unit has a connector connecting the motor and the inverter, the first storage portion has a second storage portion recessed from one axial side toward the other axial side, and the connector passes through the second storage portion to be connected to the inverter.

[0098] (4) A motor unit according to (2) or (3), wherein the rotor comprises: a rotor core having a through hole extending axially therethrough; and a fan located at an axial end of the rotor core and having at least one ventilation hole connected to the through hole.

[0099] (5) The motor unit according to any one of (2) to (4), wherein the motor housing has a flow path through which refrigerant can flow, and the pressure adjustment mechanism and an inlet of the flow path overlap in a circumferential direction of the motor axis.

[0100] (6) The motor unit according to any one of (3) to (5), wherein the motor housing has a flow path through which the refrigerant can flow, and the second housing portion overlaps with an inlet of the flow path in a circumferential direction of the motor axis.

[0101] (7) The motor unit according to any one of (3) to (6), wherein the pressure adjustment mechanism is located on one side in the axial direction of a wall constituting the second housing portion when viewed in the radial direction.

[0102] (8) The motor unit according to any one of (3) to (6), wherein the pressure adjustment mechanism is located on the other axial side of the wall constituting the second housing portion when viewed in the radial direction.

[0103] (9) The motor unit according to any one of (2) to (8), wherein the motor case has a wall portion that protrudes radially inward from an inner surface of the motor case and surrounds at least a portion of the periphery of the pressure adjustment mechanism.

[0104] (10) A motor unit according to any one of (3) to (9), wherein the motor housing has a flow path through which refrigerant can flow, one end of the flow path is located on one axial side of the motor housing, and the other end of the flow path is located on the other axial side of the motor housing, and when viewed from the radial direction, at least a portion of the second storage portion is located between the one end of the flow path and the other end of the flow path.

[0105] (11) The motor unit according to (1), wherein the motor axis, the bus bar, and the pressure adjustment mechanism are arranged in a radial direction.

[0106] (12) The motor unit according to (11), wherein the pressure adjustment mechanism is located above the motor axis and radially inward of the outer peripheral surface of the motor housing.

[0107] (13) A motor unit according to (11) or (12), wherein the motor housing comprises: a main body portion, which is in the shape of a cylinder and is open on one axial side; and a flange portion, which is arranged at an end portion on one axial side of the main body portion and extends radially toward the main body portion, and the pressure adjustment mechanism is arranged on the flange portion and overlaps with the inverter housing in the axial direction.

[0108] (14) A driving device comprising: the motor unit described in any one of (1) to (13); and a gear portion having a plurality of gears.

[0109] Description of symbols

[0110] 1: drive device; 10: motor unit; 10A: motor unit; 20: motor; 21: rotor; 30: inverter; 32: connector; 41: bus bar; 50: motor housing; 51: motor chamber; 51A: motor chamber; 53: first storage section; 60: inverter housing; 61: inverter chamber; 501: main body; 502: flange; 52: wall; 521: connecting hole; 531: second storage section; 532: opening; 532A: opening; 533: wall; 54: pressure adjustment mechanism; 54A: pressure adjustment mechanism; 55: wall; 70: gear portion; 80: flow path; 81: inlet; AX1: motor axis.

Claims

1. A motor unit comprising: A motor having a rotor rotatable about a motor axis; an inverter electrically connected to the motor; a bus bar connecting the motor and the inverter; a motor housing having a motor chamber for accommodating the motor and the bus bar; as well as An inverter housing has an inverter chamber for accommodating the inverter. At least a portion of the inverter chamber overlaps with the motor chamber in radial and axial directions, In the motor housing and the inverter housing, a wall portion for dividing the motor chamber and the inverter chamber is provided at a portion where the motor chamber and the inverter chamber overlap in the axial direction. The motor chamber and the inverter chamber are connected to each other via a connecting hole formed in the wall portion and through which the bus bar passes. The motor housing has: a first housing portion for housing the bus bar; an opening portion connecting the first housing portion and the exterior of the motor housing; and A pressure adjustment mechanism is installed at the opening.

2. The motor unit according to claim 1, wherein: The pressure adjustment mechanism is located on the outer peripheral surface of the motor case and overlaps with the bus bar in the radial direction when viewed from the axial direction.

3. The motor unit according to claim 2, wherein: The motor unit has a connector for connecting the motor and the inverter. The first housing portion includes a second housing portion that is recessed from one axial side toward the other axial side. The connector passes through the second housing portion and is connected to the inverter.

4. The motor unit according to claim 2, wherein: The rotor has: a rotor core having a through hole extending therethrough in an axial direction; and The fan is located at the axial end of the rotor core and is formed with at least one vent hole connected to the through hole.

5. The motor unit according to claim 2, wherein: The motor housing has a flow path through which the refrigerant can flow. The pressure adjustment mechanism and the inlet of the flow path overlap in the circumferential direction of the motor axis.

6. The motor unit according to claim 3, wherein: The motor housing has a flow path through which the refrigerant can flow. The second housing portion overlaps with an inlet of the flow path in a circumferential direction of the motor axis.

7. The motor unit according to claim 3, wherein: When viewed in the radial direction, the pressure adjustment mechanism is located on one side in the axial direction of a wall constituting the second housing portion.

8. The motor unit according to claim 3, wherein: When viewed in the radial direction, the pressure adjustment mechanism is located on the other axial side of the wall constituting the second housing portion.

9. The motor unit according to claim 2, wherein: The motor case includes a wall portion that protrudes radially inward from an inner side surface of the motor case and surrounds at least a portion of the periphery of the pressure adjustment mechanism.

10. The motor unit according to claim 3, wherein: The motor housing has a flow path through which the refrigerant can flow. One end of the flow path is located on one axial side of the motor housing. The other end of the flow path is located on the other axial side of the motor housing. When viewed in the radial direction, at least a portion of the second housing portion is located between one end portion of the flow path and the other end portion of the flow path.

11. The motor unit according to claim 1, wherein: The motor axis, the bus bar, and the pressure adjustment mechanism are arranged in a radial direction.

12. The motor unit according to claim 11, wherein: The pressure adjustment mechanism is located above the motor axis and radially inward of the outer peripheral surface of the motor housing.

13. The motor unit according to claim 11, wherein: The motor housing has: a main body portion in the shape of a cylinder with an opening on one axial side; and a flange portion, which is disposed at an end portion on one axial side of the main body portion and extends in a radial direction of the main body portion, The pressure adjustment mechanism is provided on the flange portion and overlaps with the inverter case in the axial direction.

14. A driving device, comprising: The motor unit according to any one of claims 1 to 13; and The gear unit includes a plurality of gears.

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