Drive device and method for manufacturing drive device

Abstract

According to one embodiment of the present invention, a drive device is provided with: a rotating electrical machine having a rotor that rotates about a central axis; a gear unit connected to the rotating electric machine on one side in the axial direction of the rotating electric machine; a housing that accommodates the rotating electric machine and the gear part; and a fluid circulating within the housing. The housing includes: a first housing portion that houses the rotating electric machine; a second accommodating part for accommodating the gear part; and a partition wall portion located between the first housing portion and the second housing portion. The partition wall portion is provided with a through-hole that connects the inner space of the first housing portion and the inner space of the second housing portion. The first housing portion has a bottom portion located on the lower side of the rotating electrical machine. At least a portion of the bottom portion faces the rotating electrical machine in the radial direction, and the bottom portion has a first surface and a second surface arranged in the circumferential direction. The first surface is located radially outward of the second surface. Each of the first surface and the second surface is inclined radially outward toward one side in the axial direction, and is connected to an inner edge of the through hole at an end portion of the one side in the axial direction.

Description

Technical Field

[0001] The invention relates to a drive device and a method for manufacturing the drive device.

[0002] This application claims priority based on Japanese Patent Application No. 2022-105972 filed in Japan on June 30, 2022, the contents of which are cited here. Background Art

[0003] A drive device having a housing having a housing for a rotating electric machine, a housing for a gear unit, and a partition wall that partitions the interiors of these housing units. Patent Document 1 describes a power transmission device for a vehicle as such a drive device.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-119918 Summary of the invention

[0007] Problems to be solved by the invention

[0008] Sometimes, for the purpose of cooling a rotating electrical machine, a driving device stores a fluid such as oil in a housing. In this case, by providing a through hole in the partition wall portion, the fluid is transported from the inside of one storage portion to the inside of another storage portion through the through hole, so that the fluid in the housing can be circulated. However, if the through hole is simply provided in the partition wall portion, the fluid cannot be smoothly transported from the inside of one storage portion to the inside of another storage portion, and a structure that can circulate the fluid more effectively is desired.

[0009] In view of the above situation, one object of the present invention is to provide a driving device capable of smoothly conveying a fluid from one storage section to another storage section.

[0010] Means for solving problems

[0011] One embodiment of the present invention is a drive device, which has: a rotating electric machine having a rotor that rotates around a central axis; a gear part that is connected to the rotating electric machine on one axial side of the rotating electric machine; a housing that accommodates the rotating electric machine and the gear part; and a fluid that circulates in the housing. The housing has: a first housing part that accommodates the rotating electric machine; a second housing part that accommodates the gear part; and a partition wall part that is located between the first housing part and the second housing part. A through hole is provided in the partition wall part, and the through hole connects the internal space of the first housing part with the internal space of the second housing part. The first housing part has a bottom located on the lower side of the rotating electric machine. At least a portion of the bottom is radially opposed to the rotating electric machine, and the bottom has a first surface and a second surface arranged in the circumferential direction. The first surface is located radially outward of the second surface. The first surface and the second surface are each inclined radially outward as they go toward one axial side, and are connected to the inner edge of the through hole at the end on one axial side.

[0012] One aspect of the present invention is a method for manufacturing a drive device, which is the method for manufacturing the drive device described above, wherein the method comprises the following molding step: molding a shell body as a part of the shell, the shell body having at least a part of the first housing portion and the partition wall portion. The molding step is a step of causing molten metal to flow into a cavity provided between a first mold located on one axial side and a second mold located on the other axial side, thereby molding the shell body. The first mold comprises: a first mold surface that molds a surface of the partition wall portion facing one axial side; and a protrusion that protrudes from the first mold surface to the other axial side. The second mold comprises: a second mold surface that molds a surface of the partition wall portion facing the other axial side; and a step surface that is located on the other axial side relative to the second mold surface and is axially opposed to the protrusion. The outer peripheral surface of the protrusion molds the inner edge of the through hole, the first surface, and the second surface.

[0013] Effects of the Invention

[0014] According to one aspect of the present invention, it is possible to provide a driving device capable of smoothly conveying a fluid from one storage section to another storage section. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of a driving device of one embodiment.

[0016] Figure 2 is a perspective view of the bottom of a housing of one embodiment.

[0017] Figure 3is a cross-sectional view of the bottom of a housing of one embodiment.

[0018] Figure 4 This is a schematic diagram for explaining a molding process of a case body according to one embodiment. DETAILED DESCRIPTION

[0019] Hereinafter, a driving device according to an embodiment of the present invention will be described with reference to the drawings.

[0020] In the following description, the vertical direction is specified and described according to the positional relationship when the drive device of the embodiment shown in each figure is mounted on a vehicle located on a horizontal road surface. In addition, in the accompanying drawings, the XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is the vertical direction. The +Z side is the upper side in the vertical direction, and the -Z side is the lower side in the vertical direction. In the following description, the upper side in the vertical direction is referred to as the "upper side", and the lower side in the vertical direction is referred to 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 drive device. In the following embodiments, the +X side is the front side of the vehicle, and the -X side is the rear side of the vehicle. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, and is the left-right direction of the vehicle, that is, the vehicle width direction. In the following embodiments, the +Y side is the left side of the vehicle, and the -Y side is the right side of the vehicle. The front-to-back direction and the left-to-right direction are horizontal directions perpendicular to the vertical direction.

[0021] The center axis J1 shown appropriately in each figure extends in 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 center axis J1 is referred to as the "axial direction", the radial direction centered on the center axis J1 is referred to as the "radial direction", and the circumferential direction centered on the center axis J1, that is, the direction around the center axis J1 is referred to as the "circumferential direction". In addition, in the following description, the +Y side in the axial direction along the center axis J1 is sometimes referred to as the axial one side, and the -Y side is sometimes referred to as the axial other side.

[0022] In addition, the up-down direction, the upper side, and the lower side are merely names used to describe the configuration relationship of each part, and the actual configuration relationship may be a configuration relationship other than the configuration relationship represented by these names. Furthermore, the effects of the embodiment can be reproduced even when the directions described as one axial side and the other axial side are interchanged.

[0023] Figure 1 It is a schematic diagram of a driving device 1 according to one embodiment.

[0024] The drive device 1 is mounted on a vehicle having a motor as a power source, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV), and is used as the power source of the vehicle.

[0025] The drive device 1 includes a rotary electric machine 2 , a gear unit 3 , a housing 80 that accommodates the rotary electric machine 2 and the gear unit 3 , a fluid O that circulates in the housing 80 , a cooler 9 that cools the fluid O, and a pump 8 that pumps the fluid O.

[0026] (case)

[0027] The housing 80 includes a housing body 80A, a motor cover 80B, and a gear cover 80C. The housing body 80A, the motor cover 80B, and the gear cover 80C are different components. The motor cover 80B is arranged on the other axial side (-Y side) of the housing body 80A. The gear cover 80C is arranged on one axial side (+Y side) of the housing body 80A.

[0028] The housing 80 has a first housing portion 81 for housing the rotating electrical machine 2, a second housing portion 82 for housing the gear portion 3, and a partition wall portion 83. The second housing portion 82 is located on one axial side (+Y side) of the first housing portion 81. The partition wall portion 83 is located between the first housing portion 81 and the second housing portion 82.

[0029] The first housing portion 81 is composed of a peripheral wall portion 81d of the case body 80A and a motor cover 80B covering an opening on the other axial side (-Y side) of the peripheral wall portion 81d. The rotary electric machine 2 is disposed in a space surrounded by the case body 80A and the motor cover 80B.

[0030] The second housing portion 82 is composed of a concave portion 82d opened on one axial side (+Y side) of the housing body 80A and a gear cover 80C covering the opening of the concave portion. The gear unit 3 is arranged in a space surrounded by the housing body 80A and the gear cover 80C.

[0031] The partition wall portion 83 divides the internal space of the first housing portion 81 and the internal space of the second housing portion 82. The partition wall portion 83 is provided with a first through hole 83a and a second through hole (through hole) 83b. The first through hole 83a and the second through hole 83b allow the internal space of the first housing portion 81 and the internal space of the second housing portion 82 to communicate with each other. The shaft 21 is inserted through the first through hole 83a.

[0032] The housing 80 contains a fluid O. The fluid O circulates in a flow path 90 described later. In the present embodiment, the fluid O is oil, which is used not only to cool the rotary electric machine 2 but also to lubricate the gear unit 3. As the fluid O, in order to exert the functions of lubricating oil and cooling oil, it is preferable to use an oil equivalent to an automatic transmission lubricating oil (ATF: Automatic Transmission Fluid) having a relatively low viscosity.

[0033] A fluid reservoir P for accumulating the fluid O is provided in the lower region inside the second housing section 82 and on the upper side of the bottom 82a of the second housing section 82. The fluid O accumulated in the fluid reservoir P is lifted by the action of the gear section 3 and diffused into the second housing section 82. The fluid O diffused into the second housing section 82 is supplied to each gear of the gear section 3 in the second housing section 82, and the fluid O is spread over the tooth surfaces of the gears. The fluid O supplied to the gear section 3 for lubrication drips and is recovered in the fluid reservoir P in the second housing section 82.

[0034] In addition, the fluid O in the fluid accumulation part P is transported to the inside of the first storage part 81 through the flow path 90 described later. The fluid O transported to the inside of the first storage part 81 drips from the rotary electric machine 2 and accumulates on the upper side of the bottom 81a of the first storage part 81. The bottom 81a of the first storage part 81 is located above the bottom 82a of the second storage part 82. The fluid O accumulated on the bottom 81a of the first storage part 81 moves to the second storage part 82 via the second through hole 83b and returns to the fluid accumulation part P.

[0035] The flow path 90 is a flow path for conveying the fluid O in the fluid accumulation portion P to the inside of the first housing portion 81. The flow path 90 includes a first flow path 91, a second flow path (flow path) 92, a third flow path 93, and a fourth flow path 94. The flow path 90 is provided with a tube 94P.

[0036] The first flow path 91 is a flow path connecting the fluid storage portion P and the pump 8. The pump 8 sucks up the fluid O in the fluid storage portion P and presses it to the downstream side. The second flow path 92 is a flow path connecting the pump 8 and the cooler 9. The fluid O is cooled by the cooler 9. The third flow path 93 is a flow path connecting the cooler 9 and the internal space of the first storage portion 81. The third flow path 93 is a flow path passing through the interior of the partition wall portion 83. A tube 94P is connected to the end on the downstream side of the third flow path 93.

[0037] The fourth flow path 94 is a flow path for diffusing the fluid O into the first housing portion 81. The fourth flow path 94 is provided inside the tube 94P. The tube 94P is arranged in the internal space of the first housing portion 81 and on the upper side of the stator 30. The tube 94P extends in the axial direction in the internal space of the first housing portion 81. A plurality of discharge holes are provided in the tube 94P. The fluid O passing through the fourth flow path 94 is discharged from the discharge holes. A portion of the fluid O discharged from the discharge holes is provided to the rotary electric machine 2 to cool the rotary electric machine 2.

[0038] (Rotating Electric Machine)

[0039] In the present embodiment, the rotating electrical machine 2 is an inner rotor type motor. In addition, the rotating electrical machine 2 of the present embodiment is, for example, a three-phase AC motor. The rotating electrical machine 2 has both the function of a motor and the function of a generator. The rotating electrical machine 2 has a rotor 20 and a stator 30 .

[0040] The rotor 20 rotates about the central axis J1. The torque of the rotor 20 is transmitted to the gear unit 3. The rotor 20 includes a shaft 21, a rotor core 24, and a rotor magnet (not shown) fixed to the rotor core. The rotor core 24 is fixed to the outer peripheral surface of the shaft 21.

[0041] The shaft 21 extends along the central axis J1. The shaft 21 rotates around the central axis J1. The shaft 21 is connected to the rotor 20 inside the first housing portion 81. The shaft 21 is connected to the gear portion 3 inside the second housing portion 82.

[0042] The stator 30 surrounds the rotor 20 from the radial outside. The stator 30 and the rotor 20 are opposite to each other with a gap therebetween. The stator 30 has a stator core 32 and a coil 31. The stator 30 is held by the housing 80. The stator core 32 has a plurality of magnetic pole teeth (not shown) from the inner circumference of the annular yoke to the radial inside. Coil wires are arranged between the magnetic pole teeth. The coil wires located in the gaps between adjacent magnetic pole teeth constitute the coil 31.

[0043] (Gear Department)

[0044] The gear unit 3 is a power transmission mechanism having a plurality of gears 41, 42, 43, and 51. The gear unit 3 is connected to the rotary electric machine 2 on one axial side (+Y side) of the rotary electric machine 2. The gear unit 3 transmits the power of the rotary electric machine 2.

[0045] The gear unit 3 includes a reduction gear 4 and a differential device 5. The reduction gear 4 has a function of reducing the rotation speed of the rotary electric machine 2 and increasing the torque output from the rotary electric machine 2 according to the reduction ratio. The reduction gear 4 is connected to the shaft 21. The reduction gear 4 transmits the torque output from the rotary electric machine 2 to the differential device 5.

[0046] The reduction gear 4 includes a first gear 41, an intermediate shaft 45, and a second gear 42 and a third gear 43 fixed to the intermediate shaft 45. The torque output from the rotary electric machine 2 is transmitted to the ring gear 51 of the differential device 5 via the shaft 21, the first gear 41, the second gear 42, and the third gear 43. The gear ratio of each gear and the number of gears can be variously changed according to the required reduction ratio.

[0047] The first gear 41 is fixed to the outer peripheral surface of the shaft 21. The first gear 41 rotates together with the shaft 21 about the center axis J1. The intermediate shaft 45 extends along the intermediate axis J2 parallel to the center axis J1. The intermediate shaft 45 rotates about the intermediate axis J2. The second gear 42 and the third gear 43 are arranged in an axial direction. The second gear 42 and the third gear 43 rotate about the intermediate axis J2. The second gear 42 meshes with the first gear 41. The third gear 43 meshes with the ring gear 51 of the differential device 5.

[0048] The differential device 5 is a device for transmitting the torque output from the rotating electric machine 2 to the wheels of the vehicle. The differential device 5 has a function of transmitting the same torque to a pair of output shafts 55 while absorbing the speed difference between the left and right wheels when the vehicle turns. The differential device 5 includes a ring gear 51. The ring gear 51 rotates around a differential axis J3 parallel to the center axis J1. The torque output from the rotating electric machine 2 is transmitted to the ring gear 51 via the reduction gear 4.

[0049] (1st storage section)

[0050] Next, the first housing portion 81 of the present embodiment will be described in more detail.

[0051] like Figure 1 As shown, the first housing portion 81 houses the rotor 20 and the stator 30. The first housing portion 81 includes a peripheral wall portion 81d of a housing body 80A and a gear cover 80C.

[0052] The peripheral wall portion 81d is substantially cylindrical with the central axis J1 as the center. The peripheral wall portion 81d surrounds the rotor 20 and the stator 30 from the radially outer side. Here, the portion of the peripheral wall portion 81d that covers the rotating electrical machine 2 from the lower side is referred to as the bottom 81a. That is, the first housing portion 81 has a bottom 81a located at the lower side of the rotating electrical machine 2. The bottom 81a receives the fluid O dripping from the rotating electrical machine 2. In addition, the fluid O dripping from the rotating electrical machine 2 is accumulated on the upper side of the bottom 81a.

[0053] The opening on one axial side (+Y side) of the peripheral wall portion 81d is covered by the partition wall portion 83. On the other hand, the opening on the other axial side (-Y side) of the peripheral wall portion 81d is covered by the gear cover 80C. The partition wall portion 83 and the gear cover 80C extend along a plane perpendicular to the center axis J1. The partition wall portion 83 and the gear cover 80C are axially opposed to each other. The peripheral wall portion 81d and the partition wall portion 83 are composed of one component. On the other hand, the gear cover 80C and the peripheral wall portion 81d are separate components, which are fixed to the peripheral wall portion 81d from the other axial side (-Y side).

[0054] Figure 2 81a is a perspective view of the bottom portion of the present embodiment. Figure 3It is a cross-sectional view of the bottom portion 81 a according to the present embodiment.

[0055] In addition, in the following description, Figure 2 The direction indicated by the arrow is set as one side in the circumferential direction (+θ side), and the opposite side is set as the other side in the circumferential direction (-θ side).

[0056] like Figure 3 As shown, the bottom 81a is provided with a first recessed portion 61, a second recessed portion 62, and a weir portion 63 that divides the first recessed portion 61 and the second recessed portion 62. In the present embodiment, the direction in which the first recessed portion 61 and the second recessed portion 62 are recessed is the lower side. The first recessed portion 61 and the second recessed portion 62 extend in the axial direction. The first recessed portion 61 and the second recessed portion 62 are arranged so as to overlap each other when viewed from the axial direction. The second recessed portion 62 is located on the other axial side (-Y side) of the first recessed portion 61.

[0057] In addition, in this specification, regarding "the recessed portion is recessed in a predetermined direction", the direction in which the recessed portion is recessed only needs to include a component of the predetermined direction. In this embodiment, the direction in which the first recessed portion 61 and the second recessed portion 62 are recessed may also be a direction inclined relative to the radial direction (or downward).

[0058] The weir portion 63 protrudes radially inward at the bottom portion 81a. The weir portion 63 extends linearly in a direction perpendicular to the radial direction. The weir portion 63 has a top surface 63b, a first side surface 63c, and a second side surface 63d.

[0059] The top surface 63b faces radially inward. The top surface 63b is a flat surface extending in a straight line in a direction perpendicular to the radial direction. The top surface 63b is slightly inclined radially outward as it faces the other axial side (-Y side). Here, the edge of the top surface 63b on one axial side (+Y side) is referred to as the top 63a. That is, the bottom 81a is provided with the top 63a.

[0060] The top portion 63a extends linearly in a direction perpendicular to the radial direction. The top portion 63a is a collection of points closest to the central axis J1 among the circumferential positions of the weir portion 63. The top portion 63a is provided at the highest position of the bottom portion 81a.

[0061] The first side surface 63c is a surface facing one axial side (+Y side). The first side surface 63c is a flat surface extending radially outward from the end (i.e., the top 63a) on the one axial side (+Y side) of the top 63a. On the other hand, the second side surface 63d is a surface facing the other axial side (-Y side). The second side surface 63d faces the opposite side of the first side surface 63c in the axial direction. The second side surface 63d is a flat surface extending radially outward from the end on the other axial side (-Y side) of the top 63a.

[0062] A second flow path 92 for the fluid O to flow is provided inside the weir portion 63. The second flow path 92 is formed by drilling the inside of the weir portion 63. The second flow path 92 extends in the same direction as the direction in which the weir portion 63 extends. That is, the second flow path 92 extends in a direction perpendicular to the radial direction. Both ends of the second flow path 92 open on the outer peripheral surface of the peripheral wall portion 81d.

[0063] According to the present embodiment, the weir portion 63 is provided at the bottom 81a of the first housing portion 81, and the second flow path 92 is provided inside the weir portion 63. Thus, the second flow path 92 is provided in a manner that crosses the first housing portion 81, so that the second flow path 92 can be shortened compared to the case of bypassing the first housing portion 81. Thus, the entire length of the flow path 90 of the fluid O can be shortened, the pressure loss in the flow path 90 can be reduced, and the supply efficiency of the fluid O to the rotating electrical machine 2 can be improved.

[0064] In the present embodiment, the second flow path 92 provided inside the weir portion 63 is a flow path connecting the pump 8 and the cooler 9. The pump 8 and the cooler 9 are both auxiliary machines fixed to the outer peripheral surface of the housing 80. In addition, in order to ensure sufficient performance respectively, the pump 8 and the cooler 9 require sufficient volume and a specific shape. Therefore, the pump 8 and the cooler 9 are prone to protruding from the outer peripheral surface of the housing 80. By providing the second flow path 92 connecting the pump 8 and the cooler 9 inside the weir and passing it through the inside of the first storage portion 81, the pump 8 and the cooler 9 can be arranged separately from each other in the circumferential direction. Thus, the pump 8 and the cooler 9 can be arranged at a configuration higher than the lower end of the housing 80, and the drive device can be made thinner.

[0065] The end of the first recessed portion 61 on one axial side (+Y side) is connected to the second through hole 83b. Therefore, the first recessed portion 61 on one axial side is open to the internal space of the second housing portion 82. That is, the first recessed portion 61 is a groove extending to the second through hole 83b. On the other hand, the end of the first recessed portion 61 on the other axial side (-Y side) is closed by the weir portion 63.

[0066] like Figure 2 As shown in FIG. 1 , the inner side surface of the first recess 61 includes the first surface 61a, the second surface 61b, the fourth surface 61c, the fifth surface 61d, and the sixth surface 61e. That is, the bottom 81a includes the first surface 61a, the second surface 61b, the fourth surface 61c, the fifth surface 61d, and the sixth surface 61e. These surfaces are arranged in the order of the fourth surface 61c, the first surface 61a, the fifth surface 61d, the second surface 61b, and the sixth surface 61e toward one side (+θ side) in the circumferential direction around the central axis J1. The axial dimensions of the first surface 61a, the second surface 61b, the fourth surface 61c, the fifth surface 61d, and the sixth surface 61e are equal to each other.

[0067] The first surface 61a and the second surface 61b are surfaces facing upward. Therefore, at least a portion of the first surface 61a and the second surface 61b is opposite to the rotating electrical machine 2. The first surface 61a and the second surface 61b are arranged in the circumferential direction. The first surface 61a is located radially outward of the second surface 61b. That is, the first surface 61a is located below the second surface 61b.

[0068] The first surface 61a and the second surface 61b are respectively inclined radially outward as they are directed toward one axial side (+Y side). In addition, the first surface 61a and the second surface 61b are connected to the inner edge of the second through hole 83b at the end of one axial side (+Y side). On the other hand, the first surface 61a is connected to the first side surface 63c of the weir portion 63 at the end of the other axial side (-Y side). In addition, the second surface 61b is connected to the top surface 63b at the end of the other axial side (-Y side). The boundary line between the second surface 61b and the top surface 63b is the top 63a. The second surface 61b and the top surface 63b constitute a mountain-shaped shape with the top 63a as the vertex, which are respectively inclined radially outward as they are directed toward the opposite side of the axial direction.

[0069] The 4th surface 61c and the 5th surface 61d are opposite to each other in the circumferential direction. The 4th surface 61c faces one side in the circumferential direction (+θ side). On the other hand, the 5th surface 61d faces the other side in the circumferential direction (-θ side). The 4th surface 61c extends upward from the end of the other side in the circumferential direction (-θ side) of the 1st surface 61a. The 5th surface 61d is located between the 1st surface 61a and the 2nd surface 61b, and connects the 1st surface 61a and the 2nd surface 61b. The 5th surface 61d extends upward from the end of one side in the circumferential direction (+θ side) of the 1st surface 61a. In addition, the 5th surface 61d extends downward from the end of the other side in the circumferential direction (-θ side) of the 2nd surface 61b.

[0070] The sixth surface 61e faces the other side (-θ side) in the circumferential direction. The sixth surface 61e extends upward from an end portion of the second surface 61b on one side (+θ side) in the circumferential direction.

[0071] According to the present embodiment, the first surface 61a and the second surface 61b of the bottom 81a facing radially inwardly extend radially outwardly toward the second through hole 83b. Therefore, the fluid O accumulated in the first housing portion 81 can be guided to the second housing portion 82 via the second through hole 83b. According to the present embodiment, the fluid O can be smoothly transported from the first housing portion 81 to the second housing portion 82, and the fluid O can be effectively circulated in the housing 80.

[0072] As described above, the top portion 63a is provided at the bottom portion 81a. The top portion 63a is located on the other axial side (-Y side) of the first surface 61a and the second surface 61b, and is located radially inward of the first surface 61a and the second surface 61b. According to the present embodiment, the first surface 61a and the second surface 61b are located on the axial side (+Y side) and radially outward of the top portion 63a, so that the fluid O that is accumulated at the axial side of the top portion 63a in the fluid O dripping from the rotary electric machine 2 can be smoothly guided to the second through hole 83b.

[0073] like Figure 3 As shown, the inclination angle of the first surface 61a relative to the axial direction is set to the first angle α, and the inclination angle of the second surface 61b relative to the axial direction is set to the second angle β. Therefore, the angle formed by the first surface 61a and the central axis J1 is the first angle α, and the angle formed by the second surface 61b and the central axis J1 is the second angle β. In this embodiment, the first angle α is greater than the second angle β. Therefore, the fluid O accumulated in a deeper position of the bottom 81a can be quickly transported to the second storage portion 82.

[0074] In addition, according to the present embodiment, the top 63a can be used as a parting line between the molds, and the first surface 61a and the second surface 61b and the second through hole 83b located on one side (+Y side) of the top 63a in the axial direction can be molded by one mold. In this case, the inclination of the first surface 61a and the second surface 61b can be used as a draft taper, so the molding accuracy of the first surface 61a and the second surface 61b can be improved.

[0075] The first housing portion 81 houses the rotating electrical machine 2 . Therefore, when the liquid level of the fluid O in the first housing portion 81 becomes too high, the stirring resistance of the fluid O may inhibit the rotation of the rotor 20 .

[0076] In contrast, according to the present embodiment, by providing the first recess 61 in the bottom 81a, the fluid O dripping from the rotary electric machine 2 can be stored in the first recess 61, and the liquid level in the first housing portion 81 can be suppressed from becoming too high. In addition, by providing the first recess 61, the fluid O in the first housing portion 81 can be effectively guided to the second through hole 83b through the first recess 61.

[0077] The bottom 81a of the present embodiment is provided with a first surface 61a and a second surface 61b whose radial positions are different from each other. According to the present embodiment, the first recess 61 is deepened by the first surface 61a, thereby even if the amount of the fluid O accumulated in the area below the first storage portion 81 increases, the liquid level of the fluid O can be suppressed from reaching the rotor 20. In addition, by configuring the second surface 61b at a position higher than the first surface 61a, the fluid O dripping from the rotary electric machine 2 can be quickly guided to the second through hole 83b. In addition, by providing the second surface 61b, the thickness of the bottom 81a can be thickened in the area radially outside the second surface 61b, and the strength and rigidity of the bottom 81a can be ensured.

[0078] In the present embodiment, the 4th surface 61c constituting the inner side surface of the other circumferential side (-θ side) of the first recess 61 is inclined toward the other circumferential side (-θ side) as it moves toward the radial inner side. On the other hand, the 5th surface 61d and the 6th surface 61e constituting the inner side surface of the one circumferential side (+θ side) of the first recess 61 are inclined toward the one circumferential side (+θ side) as it moves toward the radial inner side. Therefore, the circumferential width dimension of the first recess 61 increases as it moves toward the radial inner side of the center axis J1. According to the present embodiment, the circumferential opening width of the first recess 61 can be increased, thereby increasing the storage amount of the fluid O in the first recess 61.

[0079] The end of the second recess 62 on one axial side (+Y side) is closed by the weir 63. The end of the second recess 62 on the other axial side (-Y side) is closed by the gear cover 80C. The second recess 62 is open only on the upper side and can store the fluid O.

[0080] The inner side surface of the second recessed portion 62 has a third surface 62a, a seventh surface 62b, and an eighth surface 62c. That is, the bottom portion 81a has a third surface 62a, a seventh surface 62b, and an eighth surface 62c. These surfaces are arranged in the order of the seventh surface 62b, the third surface 62a, and the eighth surface 62c toward one side (+θ side) in the circumferential direction around the central axis J1. The axial dimensions of the third surface 62a, the seventh surface 62b, and the eighth surface 62c are equal to each other.

[0081] The third surface 62a is a surface facing upward. The third surface 62a is inclined radially outward as it moves toward the other axial side (-Y side). The third surface 62a is connected to the opening of the peripheral wall portion 81d at the end on the other axial side (-Y side). On the other hand, the third surface 62a is connected to the second side surface 63d of the weir portion 63 at the end on one axial side (+Y side).

[0082] The 7th surface 62b and the 8th surface 62c are opposite to each other in the circumferential direction. The 7th surface 62b faces one side in the circumferential direction (+Y side). The 7th surface 62b extends upward from the end of the other side (-θ side) of the 3rd surface 62a in the circumferential direction. The 8th surface 62c faces the other side (-θ side) in the circumferential direction. The 8th surface 62c extends upward from the end of the one side (+θ side) of the 3rd surface 62a in the circumferential direction.

[0083] According to the present embodiment, by providing the second recess 62 at the bottom 81a, a part of the fluid O dripping from the rotary electric machine 2 can be accumulated in the second recess 62. Thus, the liquid level of the fluid O in the first storage section 81 can be suppressed from becoming too high. In addition, when the drive device 1 tilts due to the vehicle running on a slope, or when the drive device 1 vibrates due to the vehicle running on a gravel road, the fluid O accumulated in the second recess 62 flows into the first recess 61 over the weir 63, and returns to the inside of the second storage section 82 through the second through hole 83b. In addition, a flow path connected to the second recess 62 may be separately provided, and the fluid O accumulated in the second recess 62 may be returned to the inside of the second storage section 82 through the flow path.

[0084] The top surface 63 b is inclined downward toward the second recess 62 side (the other axial side (−Y side)). Therefore, the fluid O on the top surface 63 b flows toward the second recess 62 side and is stored in the second recess 62 .

[0085] According to the present embodiment, the third surface 62a is located on the other axial side (-Y side) of the top 63a. In addition, the third surface 62a is located at a position radially outward from the top 63a. The third surface 62a is inclined radially outward as it moves away from the top 63a toward the other axial side. In other words, the third surface 62a is inclined radially outward as it moves away from the weir 63 toward the other axial side.

[0086] According to the present embodiment, the top 63a can be used as a parting line between the split molds, and the third surface 62a located at the other side (-Y side) of the top 63a can be formed by a mold different from the mold for forming the first surface 61a and the second surface 61b. According to the present embodiment, the radially inner surface of the bottom 81a can be divided into regions on one side and the other side of the axial direction relative to the top 63a, and formed by different molds. At this time, the inclination of the third surface 62a can be used as a draft taper, so the molding accuracy of the third surface 62a can be improved. In addition, according to the present embodiment, the radially inner surface of the bottom 81a is divided in the axial direction and pulled out in different directions by different molds, thereby reducing the load on the mold and extending the life of the mold compared to the case where the entire axial length is pulled out by one mold.

[0087] In the present embodiment, the 7th surface 62b constituting the inner side surface of the other circumferential side (-θ side) of the second recess 62 is inclined toward the other circumferential side (-θ side) as it moves toward the radial inner side. On the other hand, the 8th surface 62c constituting the inner side surface of the one circumferential side (+θ side) of the second recess 62 is inclined toward the one circumferential side (+θ side) as it moves toward the radial inner side. Therefore, the circumferential width dimension of the second recess 62 increases as it moves toward the radial inner side of the center axis J1. According to the present embodiment, the circumferential opening width of the second recess 62 can be increased, thereby increasing the storage amount of the fluid O in the second recess 62.

[0088] like Figure 2 As shown, the circumferential opening width D2 of the second recess 62 is larger than the circumferential opening width D1 of the first recess 61. Here, the "circumferential opening width of the recess" refers to the size of the opening of the radial inner side of each recess along the circumferential direction. The circumferential opening width D1 of the first recess 61 is the distance along the horizontal direction between the upper end of the fourth surface 61c and the upper end of the sixth surface 61e. The circumferential opening width D2 of the second recess 62 is the distance along the horizontal direction between the upper end of the seventh surface 62b and the upper end of the eighth surface 62c.

[0089] According to the present embodiment, the opening width D1 of the first recess 61 is made relatively small, and the opening width D2 of the second recess 62 is made relatively large. By reducing the opening width D1 of the first recess 61, the circumferential dimension of the second through hole 83b connected to the first recess 61 can be reduced, and the rigidity of the partition wall portion 83 can be sufficiently ensured. In addition, by increasing the opening width D2 of the second recess 62, the storage amount of the fluid O that can be stored in the second recess 62 can be increased. In addition, by increasing the opening width D2 of the second recess 62, the second recess 62 can be made shallower while ensuring the storage amount of the second recess 62, and the fluid O accumulated in the second recess 62 can be easily guided to the first recess 61 by utilizing the inclination of the vehicle or the like.

[0090] Figure 4 This is a schematic diagram for explaining a molding process of the case body 80A according to the present embodiment.

[0091] The housing body 80A is a part of the housing 80, and has at least a part of the first storage portion 81, at least a part of the second storage portion 82, and a partition wall portion 83. The housing body 80A of the present embodiment is made of, for example, an aluminum alloy. In addition, the housing body 80A is formed by a die casting method such as die casting. That is, the manufacturing method of the drive device 1 has a molding process for molding the housing body 80A.

[0092] like Figure 4As shown in the figure, the molding process of the housing body 80A is performed using at least the first mold 11 and the second mold 12. In addition, the first mold 11 and the second mold 12 of this embodiment are molds for molding the inner side surface of the housing body 80A. In addition, in the molding process of this embodiment, in addition to the first mold 11 and the second mold 12, a plurality of molds (not shown) are used to mold the outer side surface of the housing body 80A.

[0093] The first die 11 and the second die 12 are arranged in the axial direction. In the molding process, the first die 11 is located on one side (+Y side) in the axial direction, and the second die is located on the other side (-Y side) in the axial direction. In the molding process, the molten metal flows into the cavity C provided between the first die 11 and the second die 12 to mold the housing body 80A.

[0094] The first mold 11 mainly molds the inner side surface of the second housing portion 82 and the first wall surface 83c facing the axial one side (+Y side) of the partition wall portion 83. The first mold 11 has a first mold outer peripheral surface 11e facing radially outward relative to the central axis J1 and a first mold front end surface (first mold surface) 11a facing the axial other side (-Y side).

[0095] The first die front end surface 11 a extends along a plane perpendicular to the central axis. The first die front end surface 11 a molds the first wall surface 83 c of the partition wall portion 83 .

[0096] The first mold outer peripheral surface 11e is a surface extending from the edge of the first mold front end surface 11a to one side in the axial direction (+Y side). The first mold outer peripheral surface 11e molds a part of the inner side surface of the second housing portion 82. The first mold outer peripheral surface 11e is an inclined surface that functions as a draft taper. That is, the first mold outer peripheral surface 11e is inclined radially outward as it moves toward one side in the axial direction (+Y side).

[0097] Furthermore, the first die 11 includes a first convex portion 11d protruding from the first die front end surface 11a toward the other axial side (-Y side) and a protruding portion 13. The first convex portion 11d has a cylindrical shape centered on the central axis J1.

[0098] The protrusion 13 is arranged below the first protrusion 11d. The protrusion height of the first protrusion 11d relative to the first die front end surface 11a is greater than the protrusion height of the first protrusion 11d relative to the first die front end surface 11a.

[0099] The protrusion 13 has a front end face 13a and an outer peripheral surface 13b. The front end face 13a extends along a plane perpendicular to the central axis J1. The outer peripheral surface 13b connects the front end face 13a with the first mold front end face 11a. The outer peripheral surface 13b has a molding area 13ba, which includes the entire circumference of the base end of the protrusion 13 and an area located at the other axial side (-Y side) than the base end and facing the radial outer side of the central axis J1. The molding area 13ba molds the inner edge of the second through hole 83b of the partition wall portion 83 and the first surface 61a and the second surface 61b of the first housing portion 81. That is, the outer peripheral surface 13b molds the inner edge of the second through hole 83b, the first surface 61a and the second surface 61b. The area facing the radial outer side in the molding area 13ba is a tapered shape that tilts toward the radial outer side as it moves toward one axial side (+Y side). The tapered shape of the molding region 13ba functions as a draft taper.

[0100] The second mold 12 mainly molds the inner side surface of the first housing portion 81 and the second wall surface 83d of the partition wall portion 83 facing the other axial side (-Y side). The second mold 12 is in a substantially cylindrical shape centered on the central axis J1. The second mold 12 has a second mold outer peripheral surface 12c facing radially outward relative to the central axis J1 and a second mold front end surface (second mold surface) 12a facing the axial side (+Y side).

[0101] The second die front end face 12a extends along a plane perpendicular to the central axis J1. The second die front end face 12a is opposed to the first die outer peripheral surface 11e with a gap therebetween. The gap between the first die front end face 11a and the second die front end face 12a is filled with molten metal material, which constitutes the partition wall portion 83.

[0102] A second protrusion 12d protruding toward one axial side (+Y side) is provided on the front end surface 12a of the second mold. That is, the second mold 12 has a second protrusion 12d. The second protrusion 12d is cylindrical with the central axis J1 as the center. The front end surface of the second protrusion 12d is in contact with the front end surface of the first protrusion 11d, or is opposed to each other with a small gap therebetween. The outer peripheral surfaces of the first protrusion 11d and the second protrusion 12d form the inner peripheral surface of the first through hole 83a. A parting line is formed at the boundary portion between the first protrusion 11d and the second protrusion 12d, and the parting line is the mating surface between the first mold 11 and the second mold 12. In addition, the inner peripheral surface of the first through hole 83a is preferably finished by machining after the molding process.

[0103] The second mold outer peripheral surface 12c is a surface extending radially inward from the end of the second mold outer peripheral surface 12c on one axial side (+Y side). The second mold outer peripheral surface 12c forms the inner side surface of the first housing portion 81. The second mold outer peripheral surface 12c is an inclined surface that functions as a draft taper. That is, the second mold outer peripheral surface 12c is inclined radially outward as it moves toward the other axial side (-Y side).

[0104] The second mold 12 is provided with a mold recess 12e, which is recessed toward the other axial side (-Y side) relative to the second mold front end face 12a and is recessed toward the radial inner side of the center axis J1 relative to the second mold outer peripheral face 12c. The mold recess 12e has a first step surface 12f and a second step surface (step surface) 12g. The first step surface 12f is located radially inward relative to the second mold outer peripheral face 12c. The first step surface 12f faces radially outward. The second step surface 12g is located axially on the other side (-Y side) relative to the second mold front end face 12a. The second step surface 12g faces axially on one side (+Y side).

[0105] The protrusion 13 is fitted into the mold recess 12e. The first step surface 12f faces the outer peripheral surface 13b of the protrusion 13. The second step surface 12g faces the protrusion 13 in the axial direction and contacts the front end surface 13a of the protrusion 13 or faces it with a small gap.

[0106] The third step surface 12h and the fourth step surface 12i are provided on the second mold outer peripheral surface 12c. The third step surface 12h and the fourth step surface 12i are provided in the area facing downward in the second mold outer peripheral surface 12c. In addition, the third step surface 12h and the fourth step surface 12i are located on the other axial side (-Y side) of the mold concave portion 12e.

[0107] The third step surface 12h is a surface facing radially outward. The third step surface 12h extends from the radially outer end of the second step surface 12g of the mold concave portion 12e to the other axial side (-Y side). The third step surface 12h is an inclined surface that inclines radially outward as it moves toward the other axial side (-Y side). The fourth step surface 12i extends radially outward from the end of the other axial side (-Y side) of the third step surface 12h.

[0108] The third step surface 12h, the fourth step surface 12i, and the front end surface 13a of the protrusion 13 form the weir portion 63 by using the metal material filled in the space surrounded by these surfaces. In addition, the corner formed by the third step surface 12h and the front end surface 13a forms the top portion 63a. The parting line as the mating surface between the first mold 11 and the second mold passes through the top portion 63a.

[0109] The present invention is not limited to the above-mentioned embodiment, and other structures can also be adopted within the scope of the technical concept of the present invention. In the above-mentioned embodiment, the case where the fluid flowing from the inside of the first housing portion through the second through hole to the inside of the second housing portion is the fluid O is described. However, the fluid is not particularly limited. The fluid can be, for example, an insulating liquid or water. In the case where the fluid is water, the surface of the stator can also be subjected to insulation treatment.

[0110] The shapes of the first recess and the second recess are not particularly limited as long as they have the above-mentioned first face and the second face. When viewed from the axial direction, the shapes of the first recess and the second recess can be, for example, semicircular, arc-shaped, or polygonal. The shape of the second through hole is not particularly limited. The second through hole can be a circular hole, a rectangular hole, or an arc-shaped hole.

[0111] The driving device is not particularly limited as long as it can move the object as a target using a rotating electric machine as a power source. The direction in which the central axis extends is not particularly limited. The central axis may also extend in the vertical direction.

[0112] In addition, in the above-mentioned embodiment, the case where the drive device does not include an inverter unit is described, but the present invention is not limited thereto. The drive device may also include an inverter unit. In other words, the drive device may also be constructed as an integral unit with the inverter unit.

[0113] The purpose of the drive device is not particularly limited. The drive device may not be mounted on the vehicle. The structures described above in this specification can be combined appropriately within the scope of non-contradiction.

[0114] In addition, the present technology can adopt the following structures.

[0115] (1) A drive device, comprising: a rotating electric machine having a rotor that rotates about a central axis; a gear portion that is connected to the rotating electric machine on one axial side of the rotating electric machine; a housing that accommodates the rotating electric machine and the gear portion; and a fluid that circulates in the housing, the housing comprising: a first housing portion that accommodates the rotating electric machine; a second housing portion that accommodates the gear portion; and a partition wall portion that is located between the first housing portion and the second housing portion, wherein a A through hole, which connects the internal space of the first housing portion with the internal space of the second housing portion, the first housing portion has a bottom located on the lower side of the rotating electric machine, at least a portion of the bottom is radially opposed to the rotating electric machine, the bottom has a first surface and a second surface arranged in the circumferential direction, the first surface is located radially outward than the second surface, the first surface and the second surface are respectively inclined radially outward as they move toward one axial side, and are connected to the inner edge of the through hole at the end on one axial side.

[0116] (2) The driving device according to (1), wherein the bottom portion is provided with a first recessed portion recessed radially outward, and an inner side surface of the first recessed portion includes the first surface and the second surface.

[0117] (3) A driving device according to (1) or (2), wherein a top portion is provided at the bottom portion and is located on the other axial side of the first surface and the second surface, and the top portion is located radially inward of the first surface and the second surface.

[0118] (4) A drive device according to (3), wherein the bottom portion has a third surface located on the other axial side of the top portion, the third surface being located radially outward relative to the top portion and inclining radially outward as it moves away from the top portion toward the other axial side.

[0119] (5) A driving device according to any one of (1) to (4), wherein the bottom is provided with: a first recess which is recessed radially outward; a second recess which is located on the other axial side of the first recess and is recessed radially outward; and a weir which divides the first recess and the second recess, wherein the inner side surface of the first recess has the first surface and the second surface, and the inner side surface of the second recess has a third surface which inclines radially outward as it moves away from the weir toward the other axial side.

[0120] (6) The driving device according to (5), wherein the opening width of the second recess in the circumferential direction is larger than the opening width of the first recess in the circumferential direction.

[0121] (7) The driving device according to (5) or (6), wherein a flow path through which the fluid flows is provided inside the weir portion.

[0122] (8) The drive device according to (7), wherein the drive device includes: a pump that pumps the fluid; and a cooler that cools the fluid, and the flow path connects the pump and the cooler.

[0123] (9) The driving device according to any one of (1) to (8), wherein an inclination angle of the first surface with respect to the axial direction is larger than an inclination angle of the second surface with respect to the axial direction.

[0124] (10) A method for manufacturing a drive device, which is a method for manufacturing a drive device as described in any one of (1) to (9), wherein the manufacturing method has the following molding step: molding a shell body as a part of the shell, the shell body having at least a part of the first storage portion and the partition wall portion, the molding step is the following step: causing molten metal to flow into a cavity arranged between a first mold located on one axial side and a second mold located on the other axial side, thereby molding the shell body, the first mold having: a first mold surface, which molds a surface of the partition wall portion facing one axial side; and a protrusion, which protrudes from the first mold surface to the other axial side, the second mold having: a second mold surface, which molds a surface of the partition wall portion facing the other axial side; and a step surface, which is located on the other axial side relative to the second mold surface and is axially opposite to the protrusion, the outer peripheral surface of the protrusion molding the inner edge of the through hole, the first surface and the second surface.

[0125] Description of symbols

[0126] 1: driving device; 2: rotating motor; 3: gear part; 8: pump; 9: cooler; 11: first mold; 11a: front end surface of first mold (first mold surface); 12: second mold; 12a: front end surface of second mold (second mold surface); 12g: second step surface (step surface); 13: protrusion; 13b: outer peripheral surface; 20: rotor; 61: first recess; 61a: first surface; 61b: second surface ; 62: second recess; 62a: third surface; 63: weir portion; 63a: top; 80: shell; 80A: shell body; 81: first receiving portion; 81a: bottom; 82: second receiving portion; 83: partition wall portion; 83b: second through hole (through hole); 92: second flow path (flow path); C: chamber; D1, D2: opening width; J1: center axis; O: fluid; α, β: inclination angle.

Claims

1. A driving device, comprising: A rotating electric machine having a rotor that rotates about a central axis; a gear portion connected to the rotating electrical machine on one axial side of the rotating electrical machine; a housing that accommodates the rotating electrical machine and the gear unit; and a fluid, which circulates within said housing, The housing has: a first housing portion for housing the rotating electrical machine; a second housing portion for housing the gear portion; and a partition wall portion located between the first storage portion and the second storage portion, The partition wall portion is provided with a through hole, the through hole communicating the internal space of the first storage portion with the internal space of the second storage portion. The first housing portion has a bottom portion located below the rotating electrical machine. At least a portion of the bottom portion is radially opposed to the rotating electrical machine, and the bottom portion has a first surface and a second surface arranged in a circumferential direction. The first surface is located radially outward of the second surface. The first surface and the second surface are each inclined radially outward as they go toward one axial side, and are connected to the inner edge of the through hole at the end on one axial side.

2. The driving device according to claim 1, wherein: The bottom is provided with a first recessed portion recessed radially outward, The inner side surface of the first recess has the first surface and the second surface.

3. The driving device according to claim 1, wherein: The bottom portion is provided with a top portion located on the other axial side of the first surface and the second surface, and the top portion is located radially inward of the first surface and the second surface.

4. The driving device according to claim 3, wherein: The bottom portion has a third surface located on the other axial side of the top portion, The third surface is located radially outward relative to the top portion, and is inclined radially outward as it moves away from the top portion toward the other axial side.

5. The driving device according to claim 1, wherein: The bottom is provided with: a first recessed portion, which is recessed radially outward; a second recessed portion, which is located on the other axial side of the first recessed portion and is recessed radially outward; and a weir portion that divides the first recessed portion and the second recessed portion, The inner side surface of the first recess has the first surface and the second surface, The inner side surface of the second recessed portion includes a third surface that is inclined radially outward as it moves away from the weir portion toward the other axial side.

6. The driving device according to claim 5, wherein: The opening width of the second recess in the circumferential direction is larger than the opening width of the first recess in the circumferential direction.

7. The driving device according to claim 5, wherein: A flow path through which the fluid flows is provided inside the weir portion.

8. The driving device according to claim 7, wherein: The drive device has: a pump that pumps the fluid; and a cooler for cooling the fluid, The flow path connects the pump and the cooler.

9. The driving device according to claim 1, wherein: An inclination angle of the first surface with respect to the axial direction is larger than an inclination angle of the second surface with respect to the axial direction.

10. A method for manufacturing a driving device, the method for manufacturing a driving device according to any one of claims 1 to 9, wherein: The manufacturing method includes the following molding steps: molding a housing body as a part of the housing, the housing body including at least a part of the first housing portion and the partition wall portion; The molding step is a step of causing molten metal to flow into a cavity provided between a first mold located on one side in the axial direction and a second mold located on the other side in the axial direction, thereby molding the housing body. The first mold has: a first mold surface that molds a surface of the partition wall portion that faces one side in the axial direction; and a protrusion protruding from the first mold surface toward the other axial side, The second mold has: a second mold surface that molds a surface of the partition wall portion that faces the other axial side; and The step surface is located on the other side of the second mold surface in the axial direction and is opposed to the protrusion in the axial direction. The outer peripheral surface of the protrusion forms the inner edge of the through hole, the first surface, and the second surface.

Images