Drive unit

Abstract

To provide a technique which can pump up the fluid and store in a storage part regardless of a rotational direction of a motor shaft.SOLUTION: In a drive device, a ring gear of a differential gear is rotatable in an opposite direction to a counter gear of a reduction gear about a third shaft. An inner surface of a gear housing that houses the reduction gear, the differential gear, and the storage part in which the fluid is stored includes: a first curved surface arranged in a +X direction from the third shaft; and a second curved surface arranged in a +X direction from the second shaft. At least a part of the first curved surface extends in a circumferential direction while facing to a radial outer end of the ring gear in a radial direction. At least a part of the second curved surface extends in a circumferential direction while facing a radial outer end of the counter gear in a radial direction. A Y-axis direction position of the storage part overlaps with the first curved surface and the second curved surface.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present invention relates to a drive device.

Background Art

[0002] Conventionally, in a drive device of a vehicle, there is known a technique of scraping up lubricating oil stored in a catch tank by a differential ring gear when the motor shaft rotates forward (see, for example, Japanese Patent Application Laid-Open No. 2019-138383).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional configuration, the lubricating oil could not be scraped up when the motor shaft rotated in the reverse direction.

[0005] An object of the present invention is to provide a technique capable of scraping up a fluid and storing it in a storage portion regardless of the direction of rotation of the motor shaft.

Means for Solving the Problems

[0006] An exemplary drive system of the present invention comprises a motor unit, a reduction gear, a differential gear, a reservoir, and a gear housing. The motor unit has a motor shaft. The motor shaft is rotatable about a first axis extending in a first direction. The reduction gear is connected to one side of the motor shaft in the first direction. The differential gear is connected to the reduction gear. The reservoir is capable of storing fluid. The gear housing houses the reduction gear, the differential gear, and the reservoir. The reduction gear has a counter gear. The counter gear is rotatable about a second axis extending in the first direction. The differential gear has a ring gear. The ring gear is rotatable about a third axis extending in the first direction in the opposite direction to the counter gear. The inner surface of the gear housing includes a first curved surface and a second curved surface. The first curved surface is located on one side of the third axis in the second direction. The second direction is perpendicular to the first direction. The second curved surface is positioned in one of the second directions relative to the second axis. At least a portion of the first curved surface extends circumferentially, facing radially from the radially outer end of the ring gear. At least a portion of the second curved surface extends circumferentially, facing radially from the radially outer end of the counter gear. The position of the reservoir in the first direction coincides with the first and second curved surfaces. [Effects of the Invention]

[0007] According to an exemplary drive device of the present invention, it is possible to provide a technology that can scoop up fluid and store it in a reservoir regardless of the direction in which the motor shaft rotates. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a cross-sectional view showing an example of the drive unit configuration as seen from the X-axis direction. [Figure 2] Figure 2 is a cross-sectional view showing an example of the drive unit configuration as seen from the Z-axis direction. [Figure 3] Figure 3 is a schematic diagram showing an example of a vehicle equipped with a drive system. [Figure 4]Figure 4 is a conceptual diagram showing an example configuration of the gear housing on the +Y direction side. [Figure 5] Figure 5 is a conceptual diagram showing an example of the configuration on the -Y direction side of the gear housing. [Figure 6] Figure 6 is a perspective view of the second housing cylinder and gear cover. [Figure 7] Figure 7 is a conceptual diagram showing another configuration example on the +Y side of the gear housing. [Modes for carrying out the invention]

[0009] An exemplary embodiment will be described below with reference to the drawings.

[0010] In the following explanation, the direction of gravity is defined and explained based on the positional relationship when the drive unit 100 is mounted on a vehicle 300 located on a horizontal road surface. In the drawings, the XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system where appropriate. In the XYZ coordinate system, the Z axis direction is an example of the "third direction" of the present invention and indicates the vertical direction (i.e., up and down direction). The +Z direction is an example of "one of the third directions" of the present invention and indicates upward (vertically upward in the opposite direction to the direction of gravity). The -Z direction is an example of "the other of the third directions" of the present invention and indicates downward (vertically downward in the same direction as the direction of gravity).

[0011] Furthermore, the X-axis direction is perpendicular to the Z-axis direction and indicates the front-rear direction of the vehicle 300 on which the drive unit 100 is mounted. Note that the X-axis direction is an example of the "second direction" of the present invention. The +X direction is an example of "one of the second directions" of the present invention and indicates one of the front and rear directions of the vehicle 300. The -X direction is an example of "the other of the second directions" of the present invention and indicates the other of the front and rear directions of the vehicle 300.

[0012] The Y-axis direction is perpendicular to both the X-axis and Z-axis directions and represents the width direction (left-right direction) of the vehicle 300. The Y-axis direction is an example of the "first direction" of the present invention. When the +X direction is the rear of the vehicle 300, the +Y direction represents the left side of the vehicle 300, and the -Y direction represents the right side of the vehicle 300. However, when the +X direction is the front of the vehicle 300, the +Y direction may represent the right side of the vehicle 300, and the -Y direction may represent the left side of the vehicle 300. That is, regardless of the X-axis direction, the +Y direction simply represents one side of the left-right direction of the vehicle 300, and the -Y direction represents the other side of the left-right direction of the vehicle 300. The +Y direction is an example of "one of the first directions" of the present invention. The -Y direction is an example of "the other of the first directions" of the present invention. Furthermore, depending on how the drive unit 100 is mounted on the vehicle 300, the X-axis direction may represent the width direction (left-right direction) of the vehicle 300, and the Y-axis direction may represent the front-rear direction of the vehicle 300. In the following, the Y-axis direction is parallel to, for example, the first axis J1 of the motor unit 2.

[0013] In the following explanation, the direction perpendicular to a predetermined axis, such as the first axis J1 to the third axis J3, will simply be referred to as the "radial direction," and the circumferential direction centered on a predetermined axis will be referred to as the "circumferential direction." Of the radial directions, the direction approaching the axis will be referred to as the "radial inward direction," and the direction moving away from the axis will be referred to as the "radial outward direction."

[0014] Furthermore, in this specification, in relation to any of the orientations, lines, and planes, "parallel" includes not only a state in which they never intersect no matter how far they are extended, but also a state in which they are substantially parallel. Similarly, "perpendicular" includes not only a state in which they intersect at a 90-degree angle, but also a state in which they are substantially perpendicular. In other words, "parallel" and "perpendicular" each include a state in which there is an angle difference between the two in their positional relationship that does not depart from the spirit of the present invention.

[0015] Furthermore, in this specification, "ring" includes not only shapes that are continuous and uninterrupted across the entire circumferential region centered on a predetermined axis such as the first axis J1 to the third axis J3, but also shapes that have one or more breaks in a part of the entire region centered on the predetermined axis. It also includes shapes that form a closed curve on a curved surface intersecting the predetermined axis.

[0016] Note that these are merely names used for explanation purposes and are not intended to limit the actual positional relationship, direction, name, etc.

[0017] <1. Embodiment> FIG. 1 is a cross-sectional view showing a configuration example of the drive device 100 as viewed from the X-axis direction. FIG. 2 is a cross-sectional view showing a configuration example of the drive device 100 as viewed from the Z-axis direction. FIG. 3 is a schematic view showing an example of a vehicle 300 on which the drive device 100 is mounted. Note that in FIG. 1, the drive device 100 is viewed from the +X direction toward the -X direction. In FIG. 2, the drive device 100 is viewed from the +Z direction toward the -Z direction. FIGS. 1 and 2 are merely conceptual diagrams, and the arrangement and dimensions of each part are not necessarily exactly the same as those of the actual drive device 100. FIG. 3 conceptually illustrates the vehicle 300.

[0018] In this embodiment, as shown in FIG. 3, the drive device 100 is mounted on at least a vehicle 300 having a motor as a power source. The vehicle 300 is, for example, a hybrid vehicle (HV), a plug-in hybrid vehicle (PHV), or an electric vehicle (EV). The vehicle 300 has the drive device 100. In FIG. 3, the drive device 100 drives the front wheels of the vehicle 300. However, it is not limited to the example shown in FIG. 3, and the drive device 100 may drive at least any one of the wheels. Further, the vehicle 300 further has a battery 200. The battery 200 stores electric power for supplying to the drive device 100.

[0019] As shown in FIGS. 1 and 2, the drive device 100 includes a motor unit 2, a gear unit 3, a housing 4, a storage unit 5, a fluid supply passage unit 6, a guide unit 7 (see FIGS. 4 to 7 described later), and a fluid circulation unit 8.

[0020] <1-1. Motor Unit 2> The motor unit 2 is a DC brushless motor. As described above, the drive unit 100 includes the motor unit 2. The motor unit 2 is the drive source for the drive unit 100 and is driven by power supplied from an inverter (not shown). The motor unit 2 is an inner rotor type in which the rotor 21 is rotatably arranged radially inward of the stator 22. As shown in Figures 1 and 2, the motor unit 2 has a motor shaft 1, a rotor 21, and a stator 22.

[0021] <1-1-1. Motor Shaft 1> The motor shaft 1 is rotatable around a first axis J1 extending in the Y-axis direction. As described above, the motor unit 2 has the motor shaft 1, and the drive device 100 includes the motor unit 2. The motor shaft 1 is cylindrical and extends in the Y-axis direction. A fluid F flows inside the motor shaft 1. The drive device 100 further includes this fluid F. In this embodiment, the fluid F is a lubricant that lubricates the bearings of the gear unit 3 and the drive device 100, and is, for example, ATF (automatic transmission fluid). The fluid F is also used as a coolant to cool the motor unit 2 and the like.

[0022] The motor shaft 1 comprises a rotor shaft 11 and a gear shaft 12. The rotor shaft 11 holds the rotor 21. The gear shaft 12 is connected to the end of the rotor shaft 11 on the +Y direction side. The rotor shaft 11 and the gear shaft 12 are cylindrical in shape and extend in the Y-axis direction, along the first axis J1. In this embodiment, the two are spline-fitted. Alternatively, they may be connected by a screw coupling using male and female threads, or joined by fixing methods such as press-fitting and welding. When fixing methods such as press-fitting and welding are adopted, serrations combining recesses and protrusions extending in the Y-axis direction may be used. With such a configuration, it is possible to reliably transmit rotation from the rotor shaft 11 to the gear shaft 12. However, the motor shaft 1 is not limited to the examples of this embodiment, and may be a single component.

[0023] The motor shaft 1 has shaft through holes 111. The shaft through holes 111 are located on the rotor shaft 11 and penetrate the cylindrical rotor shaft 11 radially. The number of shaft through holes 111 may be one or more. When the motor shaft 1 rotates, the fluid F inside it flows out of the rotor shaft 11 through the shaft through holes 111 due to centrifugal force. Note that the above examples do not exclude configurations in which the shaft through holes 111 and rotor through holes 2111 are omitted.

[0024] Furthermore, the motor shaft 1 has an inlet 121. The inlet 121 is an opening at the +Y direction end of the motor shaft 1, and in this embodiment, it is an opening at the +Y direction end of the gear shaft 12. The inlet 121 is connected to the fluid supply channel 6. Fluid F flows into the inside of the motor shaft 1 from the fluid supply channel 6 through the inlet 121.

[0025] Furthermore, the motor shaft 1 has a shaft wall portion 13. The shaft wall portion 13 is located inside the rotor shaft 11 on the -Y direction side and extends radially. The shaft wall portion 13 is also located in the -Y direction beyond the shaft through hole 111. The shaft wall portion 13 closes the opening at the -Y direction end of the rotor shaft 11. The radially outer end of the shaft wall portion 13 is connected to the inner surface of the rotor shaft 11. The shaft wall portion 13 may be integrated with the rotor shaft 11 or may be a separate component from the rotor shaft 11.

[0026] <1-1-2. Rotor 21> The rotor 21 is rotatable together with the motor shaft 1. The drive unit 100 includes the rotor 21. The rotor 21 is fixed to the motor shaft 1 and rotatable about the first axis J1. The rotor 21 rotates when power is supplied from the inverter to the stator 22. The rotor 21 has a rotor core 211 and magnets 212. The rotor core 211 is a magnetic material and is formed, for example, by stacking thin sheets of electromagnetic steel in the Y-axis direction. The rotor core 211 is fixed to the radially outer surface of the rotor shaft 11. Multiple magnets 212 are fixed to the rotor core 211. The multiple magnets 212 are arranged along the circumferential direction with their magnetic poles alternating.

[0027] Furthermore, the rotor core 211 has a rotor through-hole 2111. The rotor through-hole 2111 penetrates the rotor core 211 in the Y-axis direction and connects to the shaft through-hole 111. The rotor through-hole 2111 is used as a flow path for fluid F, which also functions as a coolant. When the rotor 21 rotates, the fluid F flowing inside the motor shaft 1 can flow into the rotor through-hole 2111 via the shaft through-hole 111. The fluid F that has flowed into the rotor through-hole 2111 can also flow out to the outside from both ends of the rotor through-hole 2111 in the Y-axis direction. The flowing fluid F is ejected towards the stator 22, cooling, for example, the coil section 222 (especially the coil end 2221), which will be described later. The flowing fluid F is also ejected towards the first motor bearing 4211 and the second motor bearing 4311, which rotatably support the motor shaft 1, lubricating and cooling them.

[0028] <1-1-3.Status 22> The stator 22 is positioned radially outward from the rotor 21. The drive unit 100 includes the stator 22. The stator 22 faces the rotor 21 with a radial gap between them. The stator 22 has a stator core 221 and a coil section 222. The stator 22 is held in a first housing cylindrical section 41, which will be described later. The stator core 221 has a plurality of magnetic pole teeth (not shown) extending radially inward from the inner surface of an annular yoke (not shown). The coil section 222 is formed by winding a conductor around the magnetic pole teeth via an insulator (not shown). The coil section 222 has a coil end 2221 protruding from the Y-axis end face of the stator core 221.

[0029] <1-2. Gear section 3> Next, the gear unit 3 is connected to the +Y direction side of the motor shaft 1 and, in this embodiment, is connected to the gear shaft 12. The gear unit 3 is a power transmission device that transmits power from the motor unit 2 to the drive shaft Ds, which will be described later. The gear unit 3 includes a reduction gear 31 and a differential gear 32.

[0030] <1-2-1. Reduction device 31> The reduction gear 31 is connected to the portion of the motor shaft 1 on the +Y direction side. The drive unit 100 includes the reduction gear 31. In this embodiment, the reduction gear 31 is connected to the gear shaft 12. The reduction gear 31 reduces the rotational speed of the motor unit 2 and increases the torque output from the motor unit 2 according to its reduction ratio. The reduction gear 31 transmits the torque output from the motor unit 2 to the differential unit 32. The reduction gear 31 includes a pinion gear 311, a counter gear 312, a drive gear 313, and an intermediate shaft 314.

[0031] The pinion gear 311 is fixed to the radially outer surface of the motor shaft 1 on the +Y direction side of the motor shaft 1. The gear section 3 has the pinion gear 311. For example, the pinion gear 311 is positioned on the radially outer surface of the gear shaft 12. The pinion gear 311 may be integrated with the gear shaft 12, or it may be separate from the gear shaft 12 and firmly fixed to the radially outer surface of the gear shaft 12. The pinion gear 311 is rotatable together with the motor shaft 1 around the first axis J1.

[0032] The intermediate shaft 314 extends along the second axis J2 and is rotatable about the second axis J2. The second axis J2 extends in the Y-axis direction. The gear section 3 has the intermediate shaft 314. Both ends of the intermediate shaft 314 are supported by the first intermediate bearing 4231 and the second intermediate bearing 4621 so as to be rotatable about the second axis J2.

[0033] The counter gear 312 is rotatable around the second shaft J2, which extends in the Y-axis direction. As described above, the reduction gear 31 has a counter gear 312. The counter gear 312 is fixed to the radially outer surface of the intermediate shaft 314 and meshes with the pinion gear 311. The drive gear 313 is fixed to the radially outer surface of the intermediate shaft 314. The gear section 3 has a counter gear 312 and a drive gear 313. The drive gear 313 is positioned in the -Y direction relative to the second gear and meshes with the ring gear 321 of the differential gear 32. The counter gear 312 and the drive gear 313 may be integrated with the intermediate shaft 314, or they may be separate from the intermediate shaft 314 and firmly fixed to the radially outer surface of the intermediate shaft 314. The counter gear 312 and the drive gear 313 are rotatable together with the intermediate shaft 314 around the second shaft J2.

[0034] The torque from the motor shaft 1 is transmitted from the pinion gear 311 to the counter gear 312. The torque transmitted to the counter gear 312 is then transmitted to the drive gear 313 via the intermediate shaft 314. Furthermore, the torque is transmitted from the drive gear 313 to the ring gear 321 of the differential 32.

[0035] <1-2-2. Differential device 32> The differential gear 32 is connected to the reduction gear 31. The drive unit 100 includes the differential gear 32. The differential gear 32 is mounted on the drive shaft Ds and transmits torque transmitted from the reduction gear 31 to the drive shaft Ds. The differential gear 32 has a ring gear 321. The ring gear 321 is rotatable in the opposite direction to the counter gear 312 around a third axis J3 extending in the Y-axis direction. The ring gear 321 meshes with the drive gear 313. The torque of the ring gear 321 is output to the drive shaft Ds.

[0036] The ring gear 321 is positioned in the -Y direction relative to the counter gear 312. By positioning the ring gear 321 in the -Y direction relative to the motor section 2 relative to the counter gear 312 in the Y-axis direction, the portion of the gear cover 46 that overlaps with the ring gear 321 in the Y-axis direction can be positioned further towards the motor section 2 (see Figures 1 and 2). Consequently, the gear housing 48, which houses the gear section 3 and will be described later, can be made more compact. Thus, this contributes to miniaturization of the drive unit 100.

[0037] The drive shaft Ds comprises a first drive shaft Ds1 and a second drive shaft Ds2. The first drive shaft Ds1 is mounted in the -Y direction of the differential 32. The second drive shaft Ds2 is mounted in the +Y direction of the differential 32. The differential 32 transmits torque to the drive shafts Ds1 and Ds2 on both sides of the Y-axis direction while absorbing the difference in rotational speed between the drive shafts Ds1 and Ds2 on both sides of the Y-axis direction, for example, when the vehicle 300 is turning.

[0038] <1-3. Housing 4> The housing 4 houses the motor section 2. More specifically, the housing 4 houses the motor shaft 1, rotor 21, stator 22, and gear section 3, etc. The housing 4 has a first housing cylindrical section 41, a side plate section 42, a housing lid section 43, a cover member 44, a second housing cylindrical section 45, and a gear lid section 46. The first housing cylindrical section 41, the side plate section 42, the housing lid section 43, the cover member 44, the second housing cylindrical section 45, and the gear lid section 46 are formed using, for example, a conductive material, and in this embodiment, they are formed using metallic materials such as iron, aluminum, or alloys thereof. Furthermore, in order to suppress galvanic corrosion at contact points, these are preferably formed using the same material. However, this is not limited to this example, and these may be formed using materials other than metallic materials, and at least some of these may be formed using different materials.

[0039] Furthermore, housing 4 also includes a motor housing 47 and a gear housing 48. These will be described later.

[0040] <1-3-1. First housing cylindrical section 41> The first housing cylindrical portion 41 is cylindrical in shape and extends in the Y-axis direction. Inside the first housing cylindrical portion 41 are the motor unit 2, a fluid reservoir 84 (described later), and other components. The stator core 221 is fixed to the inner surface of the first housing cylindrical portion 41.

[0041] <1-3-2. Side plate part 42> The side plate portion 42 covers the +Y direction end of the first housing cylindrical portion 41 and the -Y direction end of the second housing cylindrical portion 45. The side plate portion 42 extends in a direction intersecting the first axis J1, and demarcates the first housing cylindrical portion 41 and the second housing cylindrical portion 45. In this embodiment, the first housing cylindrical portion 41 and the side plate portion 42 are integrated. This increases their rigidity. However, the embodiment is not limited to this example, and the two may be separate parts.

[0042] The side plate portion 42 has a side plate through hole 4201 and a first drive shaft through hole 4202. The side plate through hole 4201 and the first drive shaft through hole 4202 penetrate the side plate portion 42 in the Y-axis direction. The center of the side plate through hole 4201 coincides with the first shaft J1. The motor shaft 1 is inserted through the side plate through hole 4201. The center of the first drive shaft through hole 4202 coincides with the third shaft J3. The first drive shaft Ds1 is inserted through the first drive shaft through hole 4202. An oil seal (not shown) is placed in the gap between the first drive shaft Ds1 and the first drive shaft through hole 4202 to seal the space between them.

[0043] The side plate portion 42 further includes a first motor bearing holder 421, a first gear bearing holder 422, a first intermediate bearing holder 423, and a first drive bearing holder 424. The first motor bearing holder 421 is located on the -Y direction side of the inner surface of the side plate through hole 4201 and holds the first motor bearing 4211. The first motor bearing 4211 rotatably supports the +Y direction end of the rotor shaft 11. The first gear bearing holder 422 is located on the +Y direction side of the inner surface of the side plate through hole 4201 and holds the first gear bearing 4221. The first gear bearing 4221 rotatably supports the -Y direction end of the gear shaft 12. The first intermediate bearing holder 423 is located on the +Y direction end face of the side plate portion 42 and holds the first intermediate bearing 4231. The first intermediate bearing 4231 rotatably supports the -Y-direction end of the intermediate shaft 314. The first drive bearing holder 424 is positioned on the inner surface of the first drive shaft through hole 4202 and holds the first drive bearing 4241. The first drive bearing 4241 rotatably supports the first drive shaft Ds1.

[0044] <1-3-3. Housing cover 43> The housing cover portion 43 extends in a direction intersecting the first axis J1 and covers the -Y direction end of the first housing cylinder portion 41. Fixation of the housing cover portion 43 to the first housing cylinder portion 41 can be, for example, by screws, but is not limited to this; a wide range of methods that firmly fix the housing cover portion 43 to the first housing cylinder portion 41 can be employed, such as screwing or press-fitting. This allows the housing cover portion 43 to be in close contact with the -Y direction end of the first housing cylinder portion 41. Close contact refers to a level of airtightness sufficient to prevent fluid F inside the component from leaking to the outside, and to prevent foreign matter such as water, dust, and dirt from entering. The same applies to close contact hereafter.

[0045] Furthermore, the housing cover 43 has a second motor bearing holder 431. The second motor bearing holder 431 holds a second motor bearing 4311. The second motor bearing 4311 rotatably supports the -Y-direction end of the rotor shaft 11. The second motor bearing holder 431 has an opening 4312 through which the rotor shaft 11 is inserted. The opening 4312 penetrates the housing cover 43 in the Y-axis direction and surrounds the first shaft J1 when viewed from the Y-axis direction.

[0046] <1-3-4. Cover member 44> The cover member 44 is positioned on the -Y-direction end face of the housing lid 43 and covers the opening 4312 and the -Y-direction end of the motor shaft 1. The cover member 44 can be attached to the housing lid 43 by, for example, screws, but is not limited to this; a wide range of methods that firmly secure the cover member 44 to the housing lid 43 can be employed, such as screwing or press-fitting. A rotation detector (e.g., a resolver) for detecting the rotor's rotation angle can be housed in the space enclosed by the cover member 44 and the housing lid 43. Furthermore, a static eliminator that electrically connects the motor shaft 1 and the housing 4 may be placed in this space.

[0047] <1-3-5. Second housing cylindrical section 45> The second housing cylinder portion 45 is cylindrical, surrounding the gear portion 3, and extends in the Y-axis direction. The -Y-direction end of the second housing cylinder portion 45 is connected to the side plate portion 42 and covered by the side plate portion 42. In this embodiment, the second housing cylinder portion 45 is detachably attached to the +Y-direction end of the side plate portion 42. The attachment of the second housing cylinder portion 45 to the side plate portion 42 can be, for example, by fixing with screws, but is not limited to this, and a wide range of methods that can firmly fix the second housing cylinder portion 45 to the side plate portion 42 can be employed, such as screwing or press-fitting. This allows the second housing cylinder portion 45 to be in close contact with the +Y-direction end of the side plate portion 42.

[0048] <1-3-6. Gear cover section 46> The gear cover portion 46 is positioned in the +Y direction relative to the counter gear 312 and extends in a direction intersecting the Y-axis direction. In this embodiment, the second housing cylindrical portion 45 and the gear cover portion 46 are integrated. However, the embodiment is not limited to this example, and the two may be separate parts.

[0049] The gear cover portion 46 has a second drive shaft through hole 460. The second drive shaft through hole 460 penetrates the gear cover portion 46 in the Y-axis direction. The center of the second drive shaft through hole 460 coincides with the third shaft J3. The second drive shaft Ds2 is inserted through the second drive shaft through hole 460. An oil seal (not shown) is placed in the gap between the second drive shaft Ds2 and the second drive shaft through hole 460.

[0050] The gear cover portion 46 further includes a second gear bearing holder 461, a second intermediate bearing holder 462, and a second drive bearing holder 463. The second gear bearing holder 461 and the second intermediate bearing holder 462 are located on the -Y direction end face of the gear cover portion 46. The second gear bearing holder 461 holds the second gear bearing 4611. The second gear bearing 4611 rotatably supports the +Y direction end of the gear shaft 12. The second intermediate bearing holder 462 holds the second intermediate bearing 4621. The second intermediate bearing 4621 rotatably supports the +Y direction end of the intermediate shaft 314. The second drive bearing holder 463 is located on the inner surface of the second drive shaft through hole 460 and holds the second drive bearing 4631. The second drive bearing 4631 rotatably supports the second drive shaft Ds2.

[0051] <1-3-7. Motor Housing 47> The motor housing 47 houses the motor unit 2. More specifically, the motor housing 47 houses the rotor shaft 11, rotor 21, and stator 22, etc. In this embodiment, the motor housing 47 is composed of a first housing cylindrical portion 41, a side plate portion 42, and a housing lid portion 43.

[0052] <1-3-8. Gear Housing 48> Next, the gear housing 48 will be described with reference to Figures 1 to 2 and Figures 4 to 6. Figure 4 is a conceptual diagram showing an example configuration of the gear housing 48 on the +Y side. Figure 5 is a conceptual diagram showing an example configuration of the gear housing 48 on the -Y side. Figure 6 is a perspective view of the second housing cylinder portion 45 and the gear cover portion 46. Note that in Figures 4 and 6, the gear housing 48 is viewed from the -Y direction toward the +Y direction. On the other hand, in Figure 5, the gear housing 48 is viewed from the +Y direction toward the -Y direction. Therefore, please note that the +X direction and -X direction in Figure 5 are opposite to the +X direction and -X direction in Figures 4 and 6, respectively.

[0053] The gear housing 48 houses the gear shaft 12 and the gear section 3. In particular, the gear housing 48 houses the reduction gear 31, the differential gear 32, and the storage section 5. As described above, the drive unit 100 has a gear housing 48. In this embodiment, the gear housing 48 is composed of a side plate section 42, a second housing cylindrical section 45, and a gear cover section 46. That is, the gear housing 48 has a side plate section 42 and a second housing cylindrical section 45. The gear housing 48 also has a gear cover section 46.

[0054] Furthermore, the gear housing 48 includes a first gear bearing 4221 and a second gear bearing 4611, and a first gear bearing holder 422 and a second gear bearing holder 461. The first gear bearing 4221 and the second gear bearing 4611 each rotatably support the gear shaft 12 via the first gear bearing holder 422 and the second gear bearing holder 461, respectively.

[0055] The gear housing 48 also includes a first intermediate bearing 4231 and a second intermediate bearing 4621, and a first intermediate bearing holder 423 and a second intermediate bearing holder 462. The first intermediate bearing holder 423 and the second intermediate bearing holder 462 rotatably support the intermediate shaft 314 via the first intermediate bearing 4231 and the second intermediate bearing 4621, respectively.

[0056] The gear housing 48 also has a first drive bearing 4241 and a second drive bearing 4631. The gear housing 48 also has a first drive bearing holder 424. The first drive bearing holder 424 rotatably supports the first drive shaft Ds1 via the first drive bearing 4241. The gear housing 48 also has a second drive bearing holder 463. The second drive bearing holder 463 rotatably supports the second drive shaft Ds2 via the second drive bearing 4631. The second drive bearing holder 463 is an example of a "bearing holder" of the present invention. The second drive bearing 4631 is an example of a "bearing" of the present invention.

[0057] In the following, the first gear bearing 4221, the first intermediate bearing 4231, the first drive bearing 4241, the second gear bearing 4611, the second intermediate bearing 4621, and the second drive bearing 4631 may be collectively referred to as "bearings 4221, 4231, 4241, 4611, 4621, and 4631." Also, the first gear bearing holder 422, the first intermediate bearing holder 423, the first drive bearing holder 424, the second gear bearing holder 461, the second intermediate bearing holder 462, and the second drive bearing holder 463 may be collectively referred to as "bearing holders 422, 423, 424, 461, 462, and 463."

[0058] A fluid pool P containing fluid F is located in the lower part of the gear housing 48. Part of the gear section 3 (for example, the counter gear 312 and the ring gear 321) is immersed in the fluid pool P. The fluid F accumulated in the fluid pool P is scraped up by the operation of the gear section 3 and supplied to the inside of the gear housing 48. For example, when the motor shaft 1 rotates in one circumferential direction, the fluid F is scraped up by the tooth surface of the ring gear 321, and when the motor shaft 1 rotates in the other circumferential direction, the fluid F is scraped up by the tooth surface of the counter gear 312. A portion of the scraped-up fluid F is supplied to the gears and bearings of the reduction gear 31 and differential gear 32 within the gear housing 48 and used for lubrication. Furthermore, the remaining portion of the fluid F that is scooped up is stored in the reservoir 5 and supplied to the inside of the motor shaft 1, and then supplied to the rotor 21 and stator 22 of the motor unit 2, and to the bearings in the gear housing 48, and used for cooling and lubrication.

[0059] The inner surface of the gear housing 48 includes a first curved surface 481 and a second curved surface 482.

[0060] The first curved surface 481 is positioned on one side of the X-axis direction (for example, the +X direction) relative to the third axis J3. As mentioned above, the X-axis direction is perpendicular to the Y-axis direction. As mentioned above, the inner surface of the gear housing 48 includes the first curved surface 481. At least a portion of the first curved surface 481 extends circumferentially, radially opposite to the radially outer end of the ring gear 321. In this embodiment, the first curved surface 481 is a portion of the inner surface of the second housing cylindrical portion 45 (for example, the surface on the +X direction side) and extends in the Y-axis direction. For example, the first curved surface 481 extends circumferentially along the radially outer surface (i.e., the tooth surface) of the ring gear 321, from the -Z direction side toward the +Z direction side relative to the ring gear 321.

[0061] The second curved surface 482 is positioned in the +X direction relative to the second axis J2. As described above, the inner surface of the gear housing 48 includes the second curved surface 482. At least a portion of the second curved surface 482 extends circumferentially, radially opposite to the radially outer end of the counter gear 312. In this embodiment, the second curved surface 482 is positioned on the gear cover portion 46. At least a portion of the second curved surface 482 is positioned in the +X direction relative to the counter gear 312. For example, the second curved surface 482 extends from the -Z side to the +Z side of the counter gear 312.

[0062] The position of the reservoir 5 in the Y-axis direction coincides with the first curved surface 481 and the second curved surface 482. For example, the position of the portion of the reservoir 5 on the -Y side in the Y-axis direction coincides with the first curved surface 481. The position of the portion of the reservoir 5 on the +Y side in the Y-axis direction coincides with the second curved surface 482. In this way, when the motor shaft 1 rotates in one circumferential direction (for example, counterclockwise when viewed from the +Y direction to the -Y direction), the fluid F accumulated in the gear housing 48 is scraped up by the teeth of the ring gear 321 which rotates in the same direction as the motor shaft 1, and guided by the first curved surface 481, it can move toward the reservoir 5. On the other hand, when the motor shaft 1 rotates in the other direction circumferentially (for example, clockwise when viewed from the +Y direction to the -Y direction), the fluid F accumulated in the gear housing 48 is scraped up by the teeth of the counter gear 312, which rotates in the opposite direction to the motor shaft 1, and guided by the second curved surface 482 to move toward the storage section 5. Furthermore, since the first curved surface 481 and the second curved surface 482 are part of the inner surface of the gear housing 48, it is not necessary to place ribs or the like inside the gear housing 48 to guide the fluid F. Therefore, with a simple configuration, the fluid F accumulated in the gear housing 48 can be scraped up and stored in the storage section 5 regardless of which direction the motor shaft 1 rotates.

[0063] Furthermore, the second surface 482 includes the first surface 4821 and the second surface 4822.

[0064] The first surface 4821 extends circumferentially along the radially outer end of the counter gear 312. As described above, the second curved surface 482 includes the first surface 4821. For example, the first surface 4821 extends circumferentially along the radially outer surface (i.e., tooth surface) of the counter gear 312, from the -Z direction side toward the +Z direction side of the counter gear 312. The first surface 4821 is located on the gear cover portion 46 and extends in the Y-axis direction. The first surface 4821 faces the counter gear 312 in the radial direction with respect to the second axis J2 and extends in the Y-axis direction.

[0065] The second surface 4822 extends in the +Z direction from the +Z direction end of the first surface 4821. As described above, the second curved surface 482 includes the second surface 4822. The second surface 4822 is located on the gear cover portion 46 and extends at least in the Y-axis direction. The +Z direction end of the second curved surface 482 is located in the +Z direction more than the reservoir portion 5. For example, the second surface 4822 extends at least in the Z-axis direction from the -Z direction side toward the +Z direction side toward the second reservoir portion 52, which will be described later. In this way, the fluid F moving in the +Z direction due to the scooping by the counter gear 312 can be suitably guided to the reservoir portion 5 by the second curved surface 482.

[0066] Preferably, the second surface 4822 includes a first concave surface 4823 that is recessed in the +X direction. In this embodiment, the inner surface of the first concave surface 4823 is at least a part of the second surface 4822. The arrangement of the first concave surface 4823 allows the second surface 4822 to be positioned closer to the third axis J3. For example, when viewed from the Y-axis direction, the distance between the first concave surface 4823 of the second surface 4822 and the second drive bearing 4631 positioned around the third axis J3 can be made closer to the distance between the first surface 4821 and the second drive bearing 4631 positioned around the third axis. Consequently, the bias of vibrations transmitted from the second drive bearing 4631 positioned around the third axis J3 to the second curved surface 482 can be reduced. As a result, vibrations near the second curved surface 482 can be made lower. Note that this example does not exclude a configuration in which the second surface 4822 does not include the first concave surface 4823. For example, when viewed from the Y-axis direction, the second surface 4822 may extend linearly from the connection point with the first surface 4821 toward the end on the +Z direction side.

[0067] Preferably, the second surface 4822 widens in the +X direction as it approaches the -Y direction. For example, the second surface 4822 widens in a direction that intersects the Y-axis direction diagonally. The +Y direction end of the second surface 4822 is positioned more towards the -X direction than the -Y direction end of the second surface 4822. By tilting the second surface 4822 in the Y-axis direction as described above, the free end (i.e., the -Y direction side) of the second surface 4822 can be brought closer to the third axis J3 than the fixed end (i.e., the +Y direction side) of the second surface 4822. Therefore, vibrations transmitted from the second drive bearing 4631 positioned around the third axis J3 to the second surface 4822 can be reduced. However, this example does not exclude configurations in which the second surface 4822 does not widen in the +X direction as it approaches the -Y direction. For example, the second surface 4822 may be parallel to the Y-axis direction.

[0068] Furthermore, the inner surface of the gear housing 48 further includes a first inner surface 483 and a second inner surface 484. The first inner surface 483 and the second inner surface 484 are each part of the end face on the -Y direction side of the gear cover portion 46, extending in a direction intersecting the Y-axis direction, and in this embodiment extending in a direction perpendicular to the Y-axis direction.

[0069] The first inner surface 483 is positioned in the +Y direction relative to the ring gear 321 and overlaps with the ring gear 321 in the Y-axis direction. As described above, the inner surface of the gear housing 48 further includes the first inner surface 483. The -Y direction end of the second curved surface 482 connects to the first inner surface 483.

[0070] The second inner surface 484 is positioned in the +Y direction relative to the first inner surface 483 and the counter gear 312, and overlaps with the counter gear 312 in the Y-axis direction. As described above, the inner surface of the gear housing 48 further includes the second inner surface 484. The +Y direction end of the second curved surface 482 connects to the second inner surface 484.

[0071] The second curved surface 482, the first inner surface 483, and the second inner surface 484 form a step 485. This step 485 is positioned between the portion of the gear housing 48 that overlaps with the counter gear 312 in the Y-axis direction and the portion that overlaps with the ring gear 321 in the Y-axis direction. In the above configuration, the inner surface of this step 485 facing in a direction intersecting the Y-axis direction (for example, the -X direction) can be effectively utilized as the second curved surface 482 that guides the fluid F scooped up by the counter gear 312 to the reservoir 5. In other words, the second curved surface 482 can be positioned in the gear housing 48 without forming ribs or the like that facing the counter gear 312.

[0072] <1-4. Storage Section 5> The storage section 5 is capable of storing fluid F. As described above, the drive unit 100 has a storage section 5. The storage section 5 is located inside the gear housing 48. The storage section 5 is located on one side of the Z-axis direction (for example, the +Z direction) relative to the second shaft J2. The Z-axis direction is perpendicular to the Y-axis and X-axis directions.

[0073] The storage section 5 has a recess that is concave in the -Z direction and can store fluid F scraped up by, for example, the counter gear 312 and the ring gear 321. A portion of the fluid F stored in the storage section 5 is supplied to the fluid supply channel section 6 and then to each bearing holder located in the gear housing 48. Another portion of the fluid F flows into the motor shaft 1 from the inlet 121.

[0074] Preferably, the reservoir 5 is positioned on the -X side of the counter gear 312 in the X-axis direction, beyond its outermost end (i.e., the end furthest towards the +X direction). This makes it easier for the fluid F churned up along the second curved surface 482 to enter the reservoir 5. However, this example does not exclude configurations in which the reservoir 5 is not positioned on the -X side of the counter gear 312 beyond its furthest end.

[0075] In this embodiment, the storage section 5 includes a first storage section 51 and a second storage section 52. The first storage section 51 extends from the side plate section 42 in the +Y direction. The second storage section 52 extends from the gear cover section 46 in the -Y direction. Preferably, the second storage section 52 faces the first storage section 51 in the Y-axis direction and extends along the first storage section 51 when viewed from the Y-axis direction. For example, when viewed from the Y-axis direction, the second storage section 52 overlaps with the first storage section 51. More preferably, the -Y direction end of the second storage section 52 is in contact with the +Y direction end of the first storage section 51. In this way, no gap is formed between the first storage section 51 and the second storage section 52, so the storage section 5 can suitably store the fluid F without spilling through the gap. However, this example does not exclude a configuration in which the -Y side end of the second storage section 52 faces the +Y side end of the first storage section 51 in the Y-axis direction with a gap between them. For example, the -Y side end of the second storage section 52 can be positioned near the +Y side end of the first storage section 51 in the Y-axis direction.

[0076] Furthermore, the storage section 5 is not limited to the examples of this embodiment, and may have only one of the first storage section 51 and the second storage section 52. For example, the storage section 5 may extend from the side plate section 42 in the +Y direction. In this case, the end of the storage section 5 on the +Y direction side may be in contact with the gear cover section 46, or it may be facing the gear cover section 46 in the Y-axis direction with a gap between them. Alternatively, the storage section 5 may extend from the gear cover section 46 in the -Y direction. In this case, the end of the storage section 5 on the -Y direction side may be in contact with the side plate section 42, or it may be facing the side plate section 42 in the Y-axis direction with a gap between them.

[0077] <1-5. Fluid supply channel section 6> The fluid supply passage section 6 is a passage for fluid F located in the gear housing 48. The gear housing 48 has the fluid supply passage section 6. The fluid supply passage section 6 connects the inside of the reservoir section 5 to the inside of the bearing holders 422, 423, 424, 461, 462, and 463. The fluid F stored in the reservoir section 5 can be directly supplied to the bearings 4221, 4231, 4241, 4611, 4621, and 4631 through the fluid supply passage section 6, and can suitably lubricate the bearings 4221, 4231, 4241, 4611, 4621, and 4631.

[0078] For example, the fluid supply channel section 6 includes a first supply channel section 61, a second supply channel section 62, and a third supply channel section 63. In this embodiment, these are formed inside the side plate section 42. However, the invention is not limited to this example, and at least a portion of these may be formed outside the side plate section 42.

[0079] The first supply channel section 61 connects the inside of the storage section 5 to the first gear bearing holder 422. One end of the first supply channel section 61 connects to the inside of the first storage section 51. The other end of the first supply channel section 61 connects to the side plate through hole 4201. Fluid F is supplied from the inside of the first storage section 51 to the first gear bearing holder 422 via the first supply channel section 61 and the side plate through hole 4201, lubricating and cooling the first gear bearing 4221. In addition, the fluid F flowing through the first supply channel section 61 can lubricate and cool the first motor bearing 4211.

[0080] The second supply channel section 62 connects the inside of the storage section 5 to the first intermediate bearing holder 423. In this embodiment, one end of the second supply channel section 62 is connected to the first supply channel section 61, but it may also be connected to the inside of the first storage section 51. The other end of the second supply channel section 62 is connected to the first intermediate bearing holder 423. The fluid F is supplied from the inside of the first storage section 51 through the second supply channel section 62 to the first intermediate bearing holder 423, lubricating and cooling the first intermediate bearing 4231.

[0081] The third supply channel section 63 connects the inside of the storage section 5 to the first drive bearing holder 424. One end of the third supply channel section 63 is connected to the inside of the first storage section 51. The other end of the third supply channel section 63 is connected to the first drive bearing holder 424. Fluid F is supplied from the inside of the first storage section 51 to the first drive bearing holder 424 via the third supply channel section 63, lubricating and cooling the first drive bearing 4241.

[0082] Furthermore, the fluid supply channel section 6 includes a fourth supply channel section 64, a fifth supply channel section 65, and a sixth supply channel section 66. In this embodiment, these are formed inside the gear cover section 46. However, the invention is not limited to this example, and at least some of these may be formed outside the gear cover section 46.

[0083] The fourth supply channel section 64 connects the interior of the storage section 5 to the second gear bearing holder 461. One end of the fourth supply channel section 64 connects to the interior of the second storage section 52 and is positioned in the +Y direction relative to the first inner surface 483. The other end of the fourth supply channel section 64 connects to the second gear bearing holder 461. Fluid F is supplied from the interior of the second storage section 52 to the second gear bearing holder 461 via the fourth supply channel section 64. A portion of the fluid F flowing through the fourth supply channel section 64 can lubricate and cool the second gear bearing 4611. Another portion of the fluid F flowing through the fourth supply channel section 64 can flow into the interior of the motor shaft 1 from the inlet 121.

[0084] The fifth supply channel section 65 connects the inside of the storage section 5 to the second intermediate bearing holder 462. In this embodiment, one end of the fifth supply channel section 65 is connected to the fourth supply channel section 64, but it may also be connected to the inside of the second storage section 52. One end of the fifth supply channel section 65 is positioned in the +Y direction relative to the first inner surface 483. The other end of the fifth supply channel section 65 is connected to the second intermediate bearing holder 462. The fluid F is supplied from inside the second storage section 52 to the second intermediate bearing holder 462 via the fifth supply channel section 65, thereby lubricating and cooling the second intermediate bearing 4621.

[0085] The sixth supply channel section 66 connects the inside of the storage section 5 to the second drive bearing holder 463. The sixth supply channel section 66 is an example of the "supply channel section" of the present invention. The sixth supply channel section 66 allows the fluid F stored in the storage section 5 to be directly supplied to the second drive bearing 4631. Therefore, the second drive bearing 4631 of the drive shaft Ds (specifically the second drive shaft Ds2) can be suitably lubricated.

[0086] One end of the sixth supply channel section 66 is connected to the interior of the second storage section 52 and is positioned in the +Y direction relative to the first inner surface 483. This allows the position of one end of the sixth supply channel section 66 in the Y-axis direction to be brought closer to one end of the fourth supply channel section 64 (and one end of the fifth supply channel section 65), thereby adjusting the channel length of the sixth supply channel section 66. Consequently, the channel length of the sixth supply channel section 66 can be brought closer to that of the fourth supply channel section 64 and the fifth supply channel section 65. This allows the flow rate of the fluid F flowing through the sixth supply channel section 66 to be adjusted to, for example, the same as the flow rate of the fluid F flowing through the fourth supply channel section 64 and the fifth supply channel section 65.

[0087] Furthermore, the other end of the sixth supply channel 66 is connected to the second drive bearing holder 463. The fluid F is supplied from inside the second reservoir 52 through the sixth supply channel 66 to the second drive bearing holder 463, thereby lubricating and cooling the second drive bearing 4631.

[0088] In this embodiment, the sixth supply channel 66 is positioned in the +Y direction from the -Y end of the second curved surface 482, and more specifically, in the +Y direction from the +Y end of the second curved surface 482. However, it is not limited to the examples of this embodiment, and the sixth supply channel 66 may be positioned in the -Y direction from the +Y end of the second curved surface 482, or in the -Y direction from the -Y end of the second curved surface 482. The sixth supply channel 66 only needs to be positioned in at least one of the following directions: in the +Y direction from the -Y end of the second curved surface 482, or in the -Y direction from the +Y end of the second curved surface 482. Note that there may be one or more sixth supply channel sections 66. In this way, the fluid F scooped up by the counter gear 312 can be suitably guided along the second curved surface 482 to the storage section 5. However, the sixth supply channel 66 is not limited to the examples given above, and may be positioned in the same location as the +Y direction end of the second curved surface 482 in the Y-axis direction, or at the same location as the -Y direction end of the second curved surface 482. In other words, at least one sixth supply channel 66 may intersect with the Y-axis direction end of the second curved surface 482.

[0089] Furthermore, in this embodiment, the sixth supply channel 66 is positioned in the +Y direction relative to the counter gear 312. However, the invention is not limited to this example, and the sixth supply channel 66 may be positioned in the -Y direction relative to the counter gear 312. In other words, the sixth supply channel 66 only needs to be positioned in at least one of the following directions: in the +Y direction relative to the +Y end of the counter gear 312, or in the -Y direction relative to the -Y end of the counter gear 312. In this way, the fluid F scooped up by the counter gear 312 can be suitably guided to the storage section 5 without being obstructed by the sixth supply channel 66.

[0090] <1-6. Information section 7> The guide section 7 guides the fluid F scooped up by the counter gear 312 and ring gear 321 to the storage section 5. In this embodiment, the guide section 7 has a first guide section 71 and a second guide section 72. In other words, the gear housing 48 has a first guide section 71 and a second guide section 72.

[0091] The first guide portion 71 protrudes from the side plate portion 42 in the +Y direction and extends at least in the X-axis direction. The first guide portion 71 extends from the end of the first curved surface 481 toward the reservoir 5. More specifically, the first guide portion 71 extends at least in the -X direction from the +Z direction and -X direction end of the first curved surface 481. Preferably, the -X direction side of the first guide portion 71 extends in the -Z direction toward the -X direction end. The first guide portion 71 allows the fluid F, which is scooped up by the ring gear 321 and guided by the first curved surface 481, to be efficiently led toward the reservoir 5.

[0092] The second guide portion 72 protrudes from the gear cover portion 46 in the -Y direction and extends at least in the X-axis direction. The second guide portion 72 extends from the end of the second curved surface 482 toward the reservoir 5. More specifically, the second guide portion 72 extends at least in the -X direction from the +Z and -X direction ends of the second curved surface 482. Preferably, the -X direction side of the second guide portion 72 extends in the -Z direction toward the -X direction end. The second guide portion 72 allows the fluid F, which is scooped up by the counter gear 312 and guided by the second curved surface 482, to be efficiently led toward the reservoir 5.

[0093] Preferably, the second guide portion 72 faces the first guide portion 71 in the Y-axis direction and extends along the first guide portion 71 when viewed from the Y-axis direction. For example, when viewed from the Y-axis direction, the second guide portion 72 overlaps with the first guide portion 71. In this way, the fluid F guided by at least one of the first curved surface 481 and the second curved surface 482 can be guided to the reservoir 5 by both the first guide portion 71 and the second guide portion 72. For example, even if the fluid F guided from the first curved surface 481 along the first guide portion 71 spills from the Y-axis end of the first guide portion 71 towards the second guide portion 72, at least a portion of it can be guided along the second guide portion 72 to the reservoir 5. Also, even if the fluid F guided from the second curved surface 482 along the second guide portion 72 spills from the Y-axis end of the second guide portion 72 towards the first guide portion 71, at least a portion of it can be guided along the first guide portion 71 to the reservoir 5. Therefore, the scooped-up fluid F can be stored more efficiently in the storage section 5.

[0094] More preferably, the -Y-direction end of the second guide portion 72 is in contact with the +Y-direction end of the first guide portion 71. In this way, no gap is formed between the first guide portion 71 and the second guide portion 72, so that the guide portion 7 can suitably guide the fluid F to the storage portion 5 without spilling through the gap. However, this example does not exclude a configuration in which the -Y-direction end of the second guide portion 72 is gapped and faces the +Y-direction end of the first guide portion 71 in the Y-axis direction. For example, the -Y-direction end of the second guide portion 72 can be positioned near the +Y-direction end of the first guide portion 71 in the Y-axis direction.

[0095] It should be noted that the guide portion 7 is not limited to the examples of this embodiment, and may have only one of the first guide portion 71 and the second guide portion 72. For example, the guide portion 7 may extend from the side plate portion 42 in the +Y direction. In this case, the end of the guide portion 7 on the +Y direction side may be in contact with the gear cover portion 46, or there may be a gap between it and the gear cover portion 46 in the Y-axis direction. Alternatively, the guide portion 7 may extend from the gear cover portion 46 in the -Y direction. In this case, the end of the guide portion 7 on the -Y direction side may be in contact with the side plate portion 42, or there may be a gap between it and the side plate portion 42 in the Y-axis direction.

[0096] In other words, the gear housing 48 may have a configuration that includes at least one of the first guide portion 71 and the second guide portion 72. This allows the scooped-up fluid F to be efficiently stored in the storage portion 5.

[0097] <1-7. Fluid circulation section 8> Next, the fluid circulation section 8 will be described. The fluid circulation section 8 includes a piping section 81, a pump 82, a heat exchanger 83, and a fluid reservoir 84.

[0098] The piping section 81 connects the pump 82 to the fluid reservoir 84 located inside the first housing cylindrical section 41. The pump 82 draws in the fluid F stored in the fluid pool P and supplies the fluid F to the fluid reservoir 84. In this embodiment, the pump 82 is an electric pump.

[0099] The heat exchanger 83 is positioned in the piping section 81 between the pump 82 and the fluid reservoir 84. In other words, the fluid F drawn in by the pump 82 passes through the heat exchanger 83 via the piping section 81 and is then sent to the fluid reservoir 84. The heat exchanger 83 is supplied with a refrigerant such as water from an external source. The heat exchanger 83 exchanges heat between the refrigerant and the fluid F to lower the temperature of the fluid F.

[0100] The fluid reservoir 84 is a tray located inside the motor housing 47, vertically above the stator 22. A drip hole (not shown) is formed at the bottom of the fluid reservoir 84, and the motor section 2 is cooled by dripping fluid F from the drip hole. The drip hole is formed, for example, above the coil end 2221 of the coil section 222 of the stator 22, so that the coil section 222 is cooled by the fluid F.

[0101] <1-8. Modifications of Embodiments> Next, a modified example of the embodiment will be described with reference to Figure 7. Figure 7 is a conceptual diagram showing another configuration example on the +Y direction side of the gear housing 48. Note that Figure 7 shows the gear housing 48 viewed from the -Y direction toward the +Y direction. The +X and -X directions in Figure 7 are the same as the +X and -X directions in Figures 4 and 6, but are opposite to the +X and -X directions in Figure 5.

[0102] Furthermore, the following describes a modified configuration that differs from the above-described embodiment. Also, components similar to those in the above-described embodiment are denoted by the same reference numerals, and their descriptions may be omitted.

[0103] In the modified configuration, a second concave surface 4824 is provided instead of the second guide portion 72. The second concave surface 4824 is provided on the gear cover portion 46 and extends at least in the Y-axis direction. The second surface 4822 includes the second concave surface 4824. The second concave surface 4824 is provided on the +Z-direction end of the second surface 4822 and is concave toward the +Z direction. Preferably, the +Y-direction end of the first guide portion 71 is provided further in the +Z direction than the second surface 4822 and is in contact with the gear cover portion 46. This allows the fluid F, which is scooped up by the counter gear 312 and moves along the second curved surface 482, to be suitably guided to the reservoir 5 by the second concave surface 4824. Furthermore, it is not necessary to connect a member (for example, the second guide portion 72) that guides the fluid F to the reservoir 5 to the +Z-direction end of the second curved surface 482. Thus, the fluid F can be guided to the reservoir 5 with a simple configuration.

[0104] <2. Others> Embodiments of the present invention have been described above. However, the scope of the present invention is not limited to the embodiments described above. The present invention can be implemented by making various modifications to the embodiments described above without departing from the spirit of the invention. Furthermore, the matters described in the embodiments described above can be combined as appropriate and arbitrarily as long as they do not create contradictions.

[0105] Furthermore, in this embodiment and its modifications, the present invention is applied to an in-vehicle drive unit 100. However, the present invention is not limited to these examples and can also be applied to drive units and the like used in applications other than in vehicles. [Industrial applicability]

[0106] The present invention is useful, for example, in a device in which a gear section in a gear housing scoops up fluid. [Explanation of Symbols]

[0107] 100...Drive unit, 200...Battery, 300...Vehicle, 1...Motor shaft, 11...Rotor shaft, 111...Shaft through hole, 112...Inlet, 12...Gear shaft, 121...Inlet, 13...Shaft wall, 2...Motor section, 21...Rotor, 211...Rotor core, 2111...Rotor through hole, 212...Magnet, 22...Stator, 221...Stator core, 222...Coil section, 2221...Coil end, 3...Gear section, 31...Reduction gear, 311...Pinion gear, 3 12...Counter gear, 313...Drive gear, 314...Intermediate shaft, 32...Differential gear, 321...Ring gear, 4...Housing, 41...First housing cylinder, 42...Side plate, 4201...Side plate through hole, 4202...First drive shaft through hole, 421...First motor bearing holder, 4211...First motor bearing, 422...First gear bearing holder, 4221...Second gear bearing, 423...First intermediate bearing holder, 4231...First intermediate bearing, 424...First drive bearing Gear holder, 4241...First drive bearing, 43...Housing cover, 431...Second motor bearing holder, 4311...Second motor bearing, 4312...Opening, 44...Cover member, 45...Second housing cylinder, 46...Gear cover, 460...Second drive shaft through hole, 461...Second gear bearing holder, 4611...Second gear bearing, 462...Second intermediate bearing holder, 4621...Second intermediate bearing, 463...Second drive bearing holder, 4631...Second drive bearing, 47... • Motor housing, 48...Gear housing, 481...First curved surface, 482...Second curved surface, 4821...First surface, 4822...Second surface, 4823...First concave surface, 4824...Second concave surface, 483...First inner surface, 484...Second inner surface, 485...Step, 5...Storage section, 51...First storage section, 52...Second storage section, 6...Fluid supply channel section, 61...First supply channel section, 62...Second supply channel section, 63...Third supply channel section, 64...Fourth supply channel section, 65...Fifth supply channel section, 66...Sixth supply channel section, 7...Guide section,71...First guide section, 72...Second guide section, 8...Fluid circulation section, 81...Piping section, 72...Pump, 73...Heat exchanger, 74...Fluid reservoir, F...Fluid, P...Fluid pool, Ds...Drive shaft, Ds1...First drive shaft, Ds2...Second drive shaft, J1...First shaft, J2...Second shaft, J3...Third shaft,

Claims

1. A motor unit having a motor shaft that is rotatable around a first axis extending in a first direction, A reduction gear connected to one side of the motor shaft in the first direction, A differential connected to the aforementioned reduction gear, A storage section capable of storing fluid, The gear housing that houses the reduction gear, the differential gear, and the storage unit, Equipped with, The reduction gear has a counter gear that is rotatable around a second shaft extending in the first direction, The differential device has a ring gear that is rotatable in the opposite direction to the counter gear around a third axis extending in the first direction, The gear housing is, A side plate portion provided between the motor portion and the reduction gear in the first direction, A gear cover portion is positioned in one direction toward the first direction from the counter gear and extends in a direction intersecting the first direction, It has, The inner surface of the gear housing is A first curved surface positioned in one of the second directions perpendicular to the first direction than the third axis, A second curved surface positioned in one of the second directions relative to the second axis, Includes, At least a portion of the first curved surface extends circumferentially opposite the radially outer end of the ring gear in the radial direction, At least a portion of the second curved surface is positioned on the gear cover and extends circumferentially, facing radially from the radially outer end of the counter gear. The position of the storage portion in the first direction coincides with the first curved surface and the second curved surface, The aforementioned side plate portion is A drive bearing holder that rotatably supports the drive shaft connected to the differential via a drive bearing, A gear bearing holder that rotatably supports the motor shaft via a gear bearing, A first supply channel section connecting the inside of the storage section and the inside of the gear bearing holder, A second supply channel section connecting the inside of the storage section and the inside of the drive bearing holder, It has, The first supply channel section and the second supply channel section are The side plate portion is arranged, A drive device positioned on the other side in the first direction from the other end of the second curved surface in the first direction.

2. A motor unit having a motor shaft that is rotatable around a first axis extending in a first direction, A reduction gear connected to one side of the motor shaft in the first direction, A differential connected to the aforementioned reduction gear, A storage section capable of storing fluid, The gear housing that houses the reduction gear, the differential gear, and the storage unit, Equipped with, The reduction gear has a counter gear that is rotatable around a second shaft extending in the first direction, The differential device has a ring gear that is rotatable in the opposite direction to the counter gear around a third axis extending in the first direction, The gear housing is, A side plate portion provided between the motor portion and the reduction gear in the first direction, A gear cover portion is positioned in one direction toward the first direction from the counter gear and extends in a direction intersecting the first direction, It has, The inner surface of the gear housing is A first curved surface positioned in one of the second directions perpendicular to the first direction than the third axis, A second curved surface positioned in one of the second directions relative to the second axis, Includes, At least a portion of the first curved surface extends circumferentially opposite the radially outer end of the ring gear in the radial direction, At least a portion of the second curved surface is positioned on the gear cover and extends circumferentially, facing radially from the radially outer end of the counter gear. The position of the storage portion in the first direction coincides with the first curved surface and the second curved surface, The aforementioned side plate portion is A drive bearing holder that rotatably supports the drive shaft connected to the differential via a drive bearing, A gear bearing holder that rotatably supports the motor shaft via a gear bearing, A first supply channel section connecting the inside of the storage section and the inside of the gear bearing holder, A second supply channel section connecting the inside of the storage section and the inside of the drive bearing holder, It has, The first supply channel section and the second supply channel section are The side plate portion is arranged, A drive device positioned on the other side in the first direction of the counter gear than one end in the first direction of the counter gear.

3. A motor unit having a motor shaft that is rotatable around a first axis extending in a first direction, A reduction gear connected to one side of the motor shaft in the first direction, A differential connected to the aforementioned reduction gear, A storage section capable of storing fluid, The gear housing that houses the reduction gear, the differential gear, and the storage unit, Equipped with, The reduction gear has a counter gear that is rotatable around a second shaft extending in the first direction, The differential device has a ring gear that is rotatable in the opposite direction to the counter gear around a third axis extending in the first direction, The inner surface of the gear housing is A first curved surface positioned in one of the second directions perpendicular to the first direction than the third axis, A second curved surface positioned in one of the second directions relative to the second axis, Includes, At least a portion of the first curved surface extends circumferentially opposite the radially outer end of the ring gear in the radial direction, At least a portion of the second curved surface extends circumferentially, facing radially from the radially outer end of the counter gear, The position of the storage portion in the first direction coincides with the first curved surface and the second curved surface, The storage unit is located in one direction relative to the second axis, in a third direction. The third direction is perpendicular to the first and second directions. The second surface is, A first surface extending circumferentially along the radially outer end of the counter gear, A second surface extending from one end of the first surface in the third direction toward one of the third directions, Includes, The end of the second curved surface in the third direction is positioned on one side in the third direction relative to the storage portion. The second surface includes a second concave surface that is recessed toward one of the third directions, The second concave surface is a drive device located at one end of the second surface in the third direction.

4. A motor unit having a motor shaft that is rotatable around a first axis extending in a first direction, A reduction gear connected to one side of the motor shaft in the first direction, A differential connected to the aforementioned reduction gear, A storage section capable of storing fluid, The gear housing that houses the reduction gear, the differential gear, and the storage unit, Equipped with, The reduction gear has a counter gear that is rotatable around a second shaft extending in the first direction, The differential device has a ring gear that is rotatable in the opposite direction to the counter gear around a third axis extending in the first direction, The inner surface of the gear housing is A first curved surface positioned in one of the second directions perpendicular to the first direction than the third axis, A second curved surface positioned in one of the second directions relative to the second axis, Includes, At least a portion of the first curved surface extends circumferentially opposite the radially outer end of the ring gear in the radial direction, At least a portion of the second curved surface extends circumferentially, facing radially from the radially outer end of the counter gear, The position of the storage portion in the first direction coincides with the first curved surface and the second curved surface, The gear housing is, A first guide portion extending from the end of the first curved surface toward the storage portion, A second guide portion extending from the end of the second curved surface toward the storage portion, It has, The second guide portion is a drive device that faces the first guide portion in the first direction and extends along the first guide portion when viewed from the first direction.

5. The gear housing is, A drive bearing holder that rotatably supports the drive shaft connected to the differential via a drive bearing, A third supply channel section connects the inside of the storage section and the inside of the drive bearing holder, A drive device according to claim 3 or claim 4, having the following features.

6. The third supply channel section is, The other end of the second curved surface in the first direction is greater than the other end in the first direction, The other end of the second curved surface in the first direction is greater than one end in the first direction, The drive device according to claim 5, which is arranged in at least one of the following locations.

7. The third supply channel section is, One end of the counter gear in the first direction is greater than the other end in the first direction, The other end of the counter gear in the first direction is greater than the other end in the first direction, The drive device according to claim 5 or claim 6, which is arranged in at least one of the following locations.

8. The storage unit is located in one direction relative to the second axis, in a third direction. The third direction is perpendicular to the first and second directions. The second surface is, A first surface extending circumferentially along the radially outer end of the counter gear, A second surface extending from one end of the first surface in the third direction toward one of the third directions, Includes, The drive device according to any one of claims 1 to 2 and 4 to 7, wherein one end of the second curved surface in the third direction is positioned on one side in the third direction relative to the storage portion.

9. The gear housing is positioned on one side of the first direction relative to the counter gear and has a gear cover portion that extends in a direction intersecting the first direction. The drive device according to claim 3, wherein the second surface is arranged on the gear cover and extends at least in the first direction, and as it moves toward the other in the first direction, it extends toward one of the second directions.

10. The drive device according to any one of claims 3 and 8 to 9, wherein the second surface includes a first concave surface that is recessed toward one of the second directions.

11. The ring gear is positioned in the other direction from the counter gear in the first direction. The inner surface of the gear housing is A first inner surface positioned in one direction from the ring gear, and overlapping the ring gear in the first direction, A second inner surface is positioned in one direction to the first direction from the first inner surface and the counter gear, and overlaps with the counter gear in the first direction, It further includes, One end of the second curved surface in the first direction is connected to the second inner surface. The drive device according to any one of claims 1 to 10, wherein the other end of the second curved surface in the first direction is connected to the first inner surface.

12. The drive device according to any one of claims 1 to 11, wherein the storage portion is located on the other side in the second direction of the counter gear than the one end in the second direction of the counter gear.

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