Gear device and drive device

Abstract

The invention provides a gear device and a driving device. The gear device includes: a plurality of gears that rotate about a rotation axis extending in a first direction perpendicular to a vertical direction; and a gear housing that accommodates the plurality of gears therein. The gear housing has a first through portion that connects the inside of the gear housing and the outside of the gear housing. The first through portion has an inner opening portion that opens inside the gear housing and an outer opening portion that opens outside the gear housing. The outer opening is closed by the first bolt member. The entire outer opening is provided at a position different from that of the plurality of gears in the first direction.

Description

Technical Field

[0001] The present invention relates to a gear device and a drive device. Background Art

[0002] Conventionally, a drive device in which lubricating oil is stored in a gear chamber has been known (for example, Patent Document 1).

[0003] Patent Document 1: International Publication No. 2012 / 046307

[0004] In a drive device as described above, for example, in order to inject lubricating oil or the like into the gear chamber, a through-hole connecting the inside of the gear chamber and the outside of the gear chamber is sometimes provided in a gear housing provided with the gear chamber. In this case, since a part of the lubricating oil, which is a fluid scattered in the gear chamber by being lifted by the gear or the like, accumulates in the through-hole, the lubricating oil supplied to the gear, bearings, etc. may be insufficient. Summary of the Invention

[0005] In view of the above circumstances, an object of the present invention is to provide a gear device and a drive device having a structure capable of suppressing the accumulation of fluid in the through-hole.

[0006] One aspect of the present invention is a gear device including: a plurality of gears that rotate around a rotation axis extending in a first direction perpendicular to the vertical direction; and a gear housing that houses the plurality of gears therein. The gear housing has a first through-hole that connects the inside of the gear housing and the outside of the gear housing. The first through-hole has: an inner opening that opens inside the gear housing; and an outer opening that opens outside the gear housing. The outer opening is closed by a first bolt member. The entire outer opening is provided at a position different from that of the plurality of gears in the first direction.

[0007] One aspect of the present invention is a drive device including the above-described gear device and a motor connected to the gear device.

[0008] According to one aspect of the present invention, in the gear device and the drive device, it is possible to suppress the accumulation of fluid in the through-hole. Brief Description of the Drawings

[0009] Figure 1 FIG. is a perspective view showing a drive device according to a first embodiment.

[0010] Figure 2 FIG. is a schematic cross-sectional view showing the drive device according to the first embodiment.

[0011] Figure 3 FIG. is a view of the drive device according to the first embodiment as viewed from one axial side.

[0012] Figure 4 This is a view of the drive device of the first embodiment as observed from above.

[0013] Figure 5 This is a cutaway perspective view showing a part of the gear device of the first embodiment.

[0014] Figure 6 This is a cross-sectional view showing a part of the gear device of the first embodiment.

[0015] Figure 7 This is a cross-sectional view showing a part of the process of injecting oil into the interior of the gear housing of the first embodiment.

[0016] Figure 8 This is a view of the drive device of the second embodiment as observed from one axial side.

[0017] Figure 9 This is a view of the drive device of the third embodiment as observed from one axial side.

[0018] Figure 10 This is a view of the drive device of the fourth embodiment as observed from one axial side.

[0019] Figure 11 This is a view of the drive device of the fifth embodiment as observed from one axial side.

[0020] Figure 12 This is a cross-sectional view showing a part of the drive device of the sixth embodiment.

[0021] Reference Numeral Explanation

[0022] 10: Motor; 20, 220, 320, 420, 520, 620: Gear device; 21: Reduction gear; 22: Differential device; 23a: First gear shaft (gear shaft); 24a: First gear (lower gear); 24b: Second gear (upper gear); 24c: Third gear (upper gear); 25a, 25b, 25c, 25e: Bearing; 30: Housing; 32, 432, 532, 632: Gear housing; 32c: Radial inner surface; 32e: Clearance; 35c: Bearing holding part (upper bearing holding part); 41: First bolt member; 42: Second bolt member; 43: Third bolt member; 51, 251, 351, 451, 551, 651: First through-hole; 51c, 251c, 351c, 451c, 551c: Outer opening; 51d, 251d, 351d, 451d, 551d, 651d, 651e: Inner opening; 51e, 551e: Inclined surface; 52: Second through-hole; 52a, 53a: Opening; 53: Third through-hole; 60: Control device; 61, 62: Connector part; 90: Oil (fluid); 100, 200, 300, 400, 500, 600: Driving device; 570: Second storage part (storage part); 632e: Suction port; 680: Pump; J1: Central axis (rotation axis); J2: Intermediate axis (rotation axis); J3: Differential axis (rotation axis). Detailed Description of the Invention

[0023] In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is the up-down direction. The side toward which the arrow of the Z-axis points (+Z side) is the upper side, and the opposite side of the side toward which the arrow of the Z-axis points (-Z side) is the lower side. The X-axis direction is a direction perpendicular to the Z-axis direction and is the front-rear direction of the vehicle on which the driving device in the following embodiments is mounted. In the following embodiments, the side toward which the arrow of the X-axis points (+X side) is the front side of the vehicle, and the opposite side of the side toward which the arrow of the X-axis points (-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 side toward which the arrow of the Y-axis points (+Y side) is the left side of the vehicle, and the opposite side of the side toward which the arrow of the Y-axis points (-Y side) is the right side of the vehicle.

[0024] In addition, the positional relationship in the front-rear direction is not limited to the positional relationship in the following embodiments. It may also be that the +X side is the rear side of the vehicle and the -X side is the front side of the vehicle. In this case, the +Y side is the right side of the vehicle and the -Y side is the left side of the vehicle. In addition, in this specification, the "parallel direction" also includes a substantially parallel direction, and the "perpendicular direction" also includes a substantially perpendicular direction.

[0025] The appropriately illustrated central axis J1 is an imaginary axis extending in a direction intersecting the vertical direction. More specifically, the central axis J1 extends in the Y-axis direction perpendicular to the vertical direction, that is, the left-right direction of the vehicle. In the following description, unless otherwise specified, the direction parallel to the central axis J1 is simply referred to as the "axial direction", the radial direction centered on the central axis J1 is simply referred to as the "radial direction", and the circumferential direction centered on the central axis J1 is simply referred to as the "circumferential direction". In the following description, the left side (+Y side) in the axial direction is referred to as the "axial one side", and the right side (-Y side) in the axial direction is referred to as the "axial other side". The vertical direction is, for example, the plumb direction, and the front-rear direction and the left-right direction (axial direction) are, for example, horizontal directions perpendicular to the plumb direction. In the following embodiments, the left-right direction (axial direction, Y-axis direction) corresponds to the "first direction" perpendicular to the vertical direction, and the front-rear direction (X-axis direction) corresponds to the "second direction" perpendicular to both the first direction and the vertical direction. The axial one side (+Y side) is, for example, the first direction one side. The axial other side (-Y side) is, for example, the first direction other side. The front side (+X side) is, for example, the second direction one side. The rear side (-X side) is, for example, the second direction other side.

[0026] <First Embodiment>

[0027] Figure 1 The shown drive device 100 of the present embodiment is a drive device mounted on a vehicle and rotating an axle. The vehicle equipped with the drive device 100 is a vehicle using a motor as a power source, such as a hybrid electric vehicle (HEV: Hybrid Electric Vehicle), a plug-in hybrid vehicle (PHV: Plug-in Hybrid Vehicle), or an electric vehicle (EV: Electric Vehicle). As Figure 1 shown, the drive device 100 has a motor 10, a gear device 20, and a control device 60.

[0028] The motor 10 is connected to the gear device 20. As Figure 2 shown, the motor 10 has: a rotor 11 that can rotate about the central axis J1; a stator 12 that faces the rotor 11 with a gap therebetween; and a motor housing 31. The gear device 20 has a gear mechanism 20a and a gear housing 32. The gear device 20 transmits the rotation of the rotor 11, which will be described later, in the motor 10 to the vehicle axle.

[0029] The rotor 11 has a motor shaft 13 disposed along the central axis J1 and a rotor core 14 fixed to the outer peripheral surface of the motor shaft 13. The motor shaft 13 can rotate about the central axis J1. The motor shaft 13 extends in the axial direction. The stator 12 is located radially outside the rotor 11. The stator 12 is annular and surrounds the rotor 11. The stator 12 has a stator core 15 and a plurality of coils 16.

[0030] The gear mechanism 20a is connected to the rotor 11. More specifically, the gear mechanism 20a is connected to the end portion on the axial one side (+Y side) of the motor shaft 13. The gear mechanism 20a transmits the rotation of the rotor 11 to the axle of the vehicle. The gear mechanism 20a has a reduction gear 21 connected to the rotor 11 and a differential gear 22 connected to the reduction gear 21. That is, the gear device 20 has the reduction gear 21 and the differential gear 22.

[0031] The reduction gear 21 is connected to the end portion on the axial one side (+Y side) of the motor shaft 13. The reduction gear 21 has a first gear shaft 23a and a second gear shaft 23b extending in the axial direction, a first gear 24a, a second gear 24b, and a third gear 24c. The first gear shaft 23a is supported by a pair of bearings 25a, 25b provided in the gear device 20 so as to be rotatable about the central axis J1. The first gear shaft 23a is connected to the end portion on the axial one side of the motor shaft 13. The second gear shaft 23b is rotatable about an intermediate axis J2 extending in the axial direction. In the present embodiment, the intermediate axis J2 is an imaginary axis extending parallel to the central axis J1. As Figure 3 shown, the intermediate axis J2 is located, for example, at a position above the central axis J1 and at a position rearward (-X side) of the central axis J1. As Figure 2 shown, the second gear shaft 23b is supported by a pair of bearings 25c, 25d provided in the gear device 20 so as to be rotatable about the intermediate axis J2. The bearings 25a, 25b, 25c, 25d are, for example, rolling bearings such as ball bearings. The bearings 25a, 25b are bearings that support the first gear 24a so as to be rotatable. The bearings 25c, 25d are bearings that support the second gear 24b and the third gear 24c so as to be rotatable.

[0032] The first gear 24a is a gear provided on the first gear shaft 23a. The first gear 24a is provided on the outer peripheral surface of the first gear shaft 23a. In the present embodiment, the rotation axis of the first gear 24a is the central axis J1. The second gear 24b and the third gear 24c are gears provided on the second gear shaft 23b. The second gear 24b and the third gear 24c are provided on the outer peripheral surface of the second gear shaft 23b. In the present embodiment, the rotation axes of the second gear 24b and the third gear 24c are the intermediate axis J2. That is, the third gear 24c is a gear that rotates about the same rotation axis as the second gear 24b. The second gear 24b meshes with the first gear 24a. As Figure 3 shown, the outer diameter of the second gear 24b is larger than the outer diameter of the third gear 24c. The outer diameter of the first gear 24a is smaller than the outer diameter of the third gear 24c. As Figure 4As shown, the first gear 24a and the second gear 24b are located on the axially other side (-Y side) than the third gear 24c. Further, when one of the multiple gears (the first to third gears 24a, 24b, 24c) of the gear mechanism 20a that is relatively located on the lower side is defined as the "lower-side gear" and the other gears whose rotational axes are located on the upper side than this "lower-side gear" are defined as the "upper-side gears", in the present embodiment, the first gear 24a can be referred to as the "lower-side gear", and the second gear 24b and the third gear 24c can be referred to as the "upper-side gears".

[0033] The differential device 22 has a ring gear 22a that can rotate about a differential axis J3 extending in the axial direction. In the present embodiment, the differential axis J3 is an imaginary axis that extends parallel to the central axis J1. As Figure 3 shown, in the present embodiment, the differential axis J3 is located at substantially the same position as the central axis J1 in the vertical direction. More specifically, the differential axis J3 is located on the upper side than the central axis J1. In the present embodiment, the differential axis J3 is located on the lower side than the intermediate axis J2. The differential axis J3 is set at a position different from the central axis J1 in the front-rear direction (X-axis direction). In the present embodiment, the differential axis J3 is located on the rear side (-X side) than the central axis J1 and the intermediate axis J2. The ring gear 22a is the fourth gear that meshes with the third gear 24c. As Figure 2 shown, the lower end portion of the ring gear 22a is immersed in the oil 90 stored in a later-described first storage portion 32d provided in the gear housing 32. As the ring gear 22a rotates, the oil 90 is lifted up. The lifted-up oil 90 is supplied as lubricating oil, for example, to each gear of the gear mechanism 20a and each bearing that supports each gear so as to be rotatable.

[0034] In the present embodiment, the first gear 24a, the second gear 24b, the third gear 24c, and the ring gear 22a are gears that rotate about a rotational axis extending in the axial direction perpendicular to the vertical direction. That is, in the present embodiment, the gear device 20 has four gears, namely, the first gear 24a, the second gear 24b, the third gear 24c, and the ring gear 22a, as gears that rotate about a rotational axis extending in the axial direction perpendicular to the vertical direction. Further, in the following description, without particularly distinguishing the first gear 24a, the second gear 24b, the third gear 24c, and the ring gear 22a, these gears are collectively referred to as "gears".

[0035] A pair of output shafts 29 are connected to the differential device 22. The pair of output shafts 29 extend in the axial direction. The pair of output shafts 29 are axles to which wheels of a vehicle (not shown) are respectively connected. The torque output from the motor 10 is transmitted to the wheels of the vehicle via the reduction device 21 and the differential device 22.

[0036] The motor housing 31 and the gear housing 32 are arranged axially. The motor housing 31 houses the rotor 11 and the stator 12 inside. The gear housing 32 houses the gear mechanism 20a, i.e., the reduction gear 21 and the differential gear 22, inside. That is, the gear housing 32 houses a plurality of gears including the first gear 24a, the second gear 24b, the third gear 24c, and the ring gear 22a inside. The gear housing 32 is located on the axial side (+Y side) of the motor housing 31. The gear housing 32 is connected to the motor housing 31. In the present embodiment, the housing 30 of the drive device 100 is constituted by the motor housing 31 and the gear housing 32. As Figure 1 shown, the gear housing 32 protrudes rearward (-X side) more than the motor housing 31.

[0037] As Figure 2 shown, in the present embodiment, the housing 30 has a housing main body 30a, a motor cover 30b, and a gear cover 30c. In the present embodiment, the housing main body 30a, the motor cover 30b, and the gear cover 30c are each made of metal. In addition, the materials constituting the housing main body 30a, the motor cover 30b, and the gear cover 30c are not particularly limited, and materials other than metal such as resin may also be used. The housing main body 30a, the motor cover 30b, and the gear cover 30c are separate from each other. The housing main body 30a has a first peripheral wall portion 30d, a second peripheral wall portion 30e, and a partition wall portion 30h. As Figure 4 shown, the housing main body 30a has a side wall portion 32f. In the present embodiment, the motor housing 31 is constituted by the partition wall portion 30h, the first peripheral wall portion 30d, and the motor cover 30b. In the present embodiment, the gear housing 32 is constituted by the partition wall portion 30h, the second peripheral wall portion 30e, the gear cover 30c, and the side wall portion 32f.

[0038] The first peripheral wall portion 30d is a peripheral wall portion that surrounds the stator 12 from the radially outer side. The first peripheral wall portion 30d is in a cylindrical shape that is open on the axial side (-Y side). The partition wall portion 30h is provided at the end portion on the axial side (+Y side) of the first peripheral wall portion 30d. The opening on the axial side of the first peripheral wall portion 30d is closed by the motor cover 30b fixed to the end portion on the axial side (-Y side) of the first peripheral wall portion 30d.

[0039] The second peripheral wall portion 30e of the housing main body 30a is in a cylindrical shape that is open on the axial side (+Y side). The partition wall portion 30h and the side wall portion 32f are provided at the end portion on the axial side (-Y side) of the second peripheral wall portion 30e. The opening on the axial side of the second peripheral wall portion 30e is closed by the gear cover 30c fixed to the end portion on the axial side (+Y side) of the second peripheral wall portion 30e.

[0040] As Figure 2As shown, the partition wall portion 30h divides the interior of the motor housing 31 from the interior of the gear housing 32. The partition wall portion 30h is a wall portion that axially separates the interior of the motor housing 31 from the interior of the gear housing 32. Bearings 25b and 25d are held in the partition wall portion 30h. As Figure 4 shown, the side wall portion 32f extends rearward (-X side) from the partition wall portion 30h. The side wall portion 32f forms the wall portion on the axially opposite side (-Y side) of the portion of the gear housing 32 that protrudes rearward from the motor housing 31. The partition wall portion 30h and the side wall portion 32f form the wall portion on the axially opposite side of the gear housing 32.

[0041] The gear cover 30c has: a cover wall portion 32a that covers the gear mechanism 20a from one axial side; and a third peripheral wall portion 30g that protrudes from the radially outer edge portion of the cover wall portion 32a toward the other axial side. As Figure 1 shown, in the present embodiment, the cover wall portion 32a has a substantially elliptical shape that is long in the front-rear direction (X-axis direction). The cover wall portion 32a is the wall portion on the one axial side (+Y side) of the gear housing 32. As Figure 2 shown, a bearing holding portion 35a for holding the bearing 25a and a bearing holding portion 35c for holding the bearing 25c are provided in the cover wall portion 32a. The bearing holding portion 35a has an annular shape that surrounds the central axis J1. The bearing holding portion 35c has an annular shape that surrounds the intermediate axis J2.

[0042] As Figure 3 shown, a bearing holding portion 35e is provided in the cover wall portion 32a, and the bearing holding portion 35e holds the bearing 25e that supports the gear ring 22a so as to be rotatable. The bearing 25e is a rolling bearing such as a ball bearing, for example. The bearing holding portion 35e has a cylindrical shape that surrounds the differential axis J3. As Figure 1 shown, a through hole 36 that axially penetrates the cover wall portion 32a is provided in the cover wall portion 32a. When viewed axially, the through hole 36 has a circular shape centered on the differential axis J3. The output shaft 29 passes through the through hole 36. Here, as described above, the cover wall portion 32a is a part of the gear housing 32 and has the bearing holding portions 35a, 35c, and 35e. That is, the gear housing 32 has the bearing holding portions 35a, 35e, and 35c that hold the bearings 25a, 35e, and 25c that support the plurality of gears so as to be rotatable.

[0043] As Figure 2 shown, the end portion on the other axial side (-Y side) of the third peripheral wall portion 30g is connected to the end portion on the one axial side (+Y side) of the second peripheral wall portion 30e. The second peripheral wall portion 30e and the third peripheral wall portion 30g form a gear peripheral wall portion 32b that surrounds the gear mechanism 20a from the radially outer side. As Figure 1As shown, in the present embodiment, the circumferential wall portion 32b of the gear is in a substantially elliptical cylindrical shape surrounding the central axis J1, the intermediate axis J2, and the differential axis J3.

[0044] As Figure 2 shown, in the present embodiment, the housing 30 has a first storage portion 32d for storing oil 90 as a fluid. The oil 90 is used as a lubricating oil in each gear of the gear mechanism 20a and each bearing that supports each gear for rotation. As the oil 90, for example, in order to function as a lubricating oil, it is preferable to use an oil equivalent to an automatic transmission fluid (ATF: Automatic Transmission Fluid) with a relatively low viscosity. In addition, the oil 90 can also be used as a refrigerant for cooling the motor 10. The first storage portion 32d is formed by the lower portion of the gear housing 32. The interior of the first storage portion 32d is formed by the lower region inside the gear housing 32.

[0045] In addition, the "inside of the gear housing 32" is, for example, an internal space surrounded by the surface on the other axial side (-Y side) of the cover wall portion 32a, the inner circumferential surface of the gear circumferential wall portion 32b, the surface on the axial side (+Y side) of the partition wall portion 30h, and the surface on the axial side of the side wall portion 32f.

[0046] As Figure 1 shown, the gear housing 32 has a convex portion 33 that protrudes axially from the surface on the axial side (+Y side) of the cover wall portion 32a. In the present embodiment, the convex portion 33 is provided at the upper end of the surface on the axial side of the cover wall portion 32a. The convex portion 33 is located above the central axis J1, the intermediate axis J2, and the differential axis J3. As Figure 3 shown, in the present embodiment, the convex portion 33 is located behind (-X side) the intermediate axis J2 and in front (+X side) of the differential axis J3.

[0047] As Figure 5 and Figure 6 shown, the convex portion 33 has a first portion 33a and a second portion 33b. The first portion 33a is in a substantially rectangular parallelepiped shape. In the present embodiment, the upper surface of the first portion 33a and the upper surface of the gear circumferential wall portion 32b are disposed at the same position in the vertical direction. The upper surface of the first portion 33a is connected to the upper surface of the gear circumferential wall portion 32b. The second portion 33b is located below the first portion 33a. The second portion 33b is connected to the lower end of the first portion 33a. The second portion 33b is substantially triangular when viewed in the front-rear direction (X-axis direction). The axial dimension of the second portion 33b decreases as it goes downward.

[0048] The gear housing 32 has a first through-hole portion 51 that connects the inside of the gear housing 32 to the outside of the gear housing 32. The first through-hole portion 51 has an inner opening portion 51d that opens inside the gear housing 32 and an outer opening portion 51c that opens outside the gear housing 32. In the present embodiment, the first through-hole portion 51 is used as an oil injection hole for injecting oil 90 into the inside of the gear housing 32. In the present embodiment, the first through-hole portion 51 is provided in the convex portion 33. The first through-hole portion 51 penetrates the convex portion 33. As Figure 3 shown, the first through-hole portion 51 is located at a position rearward (-X side) of the intermediate axis J2 and at a position forward (+X side) of the differential axis J3. The first through-hole portion 51 is located at a position above the center axis J1, the intermediate axis J2, and the differential axis J3.

[0049] As Figure 5 and Figure 6 shown, the first through-hole portion 51 has a hole portion 51a and a recessed portion 51b. The hole portion 51a penetrates the first portion 33a in the vertical direction. In the present embodiment, when viewed in the vertical direction, the hole portion 51a has a circular shape. The upper end portion of the hole portion 51a is the outer opening portion 51c. In the present embodiment, when viewed in the vertical direction, the outer opening portion 51c has a circular shape.

[0050] The outer opening portion 51c is closed by a first bolt member 41. The first bolt member 41 is detachably attached to the outer opening portion 51c. Alternatively, the first bolt member 41 may be non-detachably attached to the outer opening portion 51c. In the present embodiment, the first bolt member 41 is a threaded member. More specifically, the first bolt member 41 is a bolt. The first bolt member 41 has a substantially cylindrical bolt main body portion 41a extending in the vertical direction and a bolt head portion 41b connected to the upper end portion of the bolt main body portion 41a. As Figure 5As shown, the bolt main body 41a is screwed into the hole portion 51a from the upper side. A first thread portion 41c that meshes with a second thread portion 51f provided on the inner peripheral surface of the hole portion 51a is provided on the outer peripheral surface of the bolt main body 41a. In the present embodiment, the lower end portion of the bolt main body 41a is located above the lower end portion of the hole portion 51a. The bolt head 41b has a substantially disc shape that expands in a direction perpendicular to the vertical direction. The outer diameter of the bolt head 41b is larger than the outer diameter of the bolt main body 41a. The outer peripheral edge portion of the bolt head 41b is located above the peripheral edge portion of the outer opening portion 51c in the upper surface of the convex portion 33. A sealing member 44 is provided between the outer peripheral edge portion of the bolt head 41b and the peripheral edge portion of the outer opening portion 51c in the upper surface of the convex portion 33 in the vertical direction. The sealing member 44 contacts the outer peripheral edge portion of the bolt head 41b and the peripheral edge portion of the outer opening portion 51c in the upper surface of the convex portion 33. In the present embodiment, the sealing member 44 is an annular member that surrounds the bolt main body 41a. The sealing member 44 seals between the bolt head 41b and the upper surface of the convex portion 33.

[0051] As Figure 4 shown, the entire outer opening portion 51c is provided at a position different in the axial direction from a plurality of gears, namely, the first gear 24a, the second gear 24b, the third gear 24c, and the ring gear 22a. Therefore, at least a part of the first through portion 51 including the outer opening portion 51c can be arranged at a position axially offset from each gear. As a result, it is possible to prevent the oil 90 scattered in the gear housing 32 due to the rotation of the gears from easily entering the first through portion 51, and it is possible to suppress the accumulation of the oil 90 in the first through portion 51. Therefore, it is possible to suppress the shortage of the oil 90 supplied to each gear and each bearing housed in the gear housing 32. The oil 90 scattered in the gear housing 32 due to the rotation of each gear includes the oil 90 lifted by the ring gear 22a. In the present embodiment, the entire outer opening portion 51c is located on the axial side (+Y side) with respect to the first gear 24a, the second gear 24b, the third gear 24c, and the ring gear 22a.

[0052] In the present embodiment, the outer opening portion 51c opens upward. Therefore, even if the oil 90 that has entered the first through portion 51 reaches the outer opening portion 51c or the vicinity of the outer opening portion 51c, it is possible to easily cause the oil 90 to flow downward due to gravity. As a result, it is possible to further suppress the accumulation of the oil 90 in the first through portion 51. In addition, when the drive device 100 is mounted on a vehicle, even when a part of the vehicle body is disposed opposite to the axial side (+Y side) of the drive device 100, it is easy to remove the first bolt member 41 mounted on the outer opening portion 51c from the upper side of the drive device 100. In addition, as Figure 7As shown, it is possible to easily install a pipe component 91 such as a hose for injecting oil 90 into the gear housing 32 from the upper side on the open outer opening 51c. Thus, in a state where the drive device 100 is mounted on a vehicle, it is easy for an operator or the like to perform the operation of injecting oil 90 into the gear housing 32.

[0053] In addition, in this specification, "operator or the like" includes an operator who performs each operation and a device or the like. Each operation can be performed only by an operator, only by a device, or by an operator and a device.

[0054] As Figure 3 shown, the outer opening 51c is located at a position rearward (-X side) of the intermediate axis J2 and at a position forward (+X side) of the differential axis J3. The outer opening 51c is located at a position above the central axis J1, the intermediate axis J2, and the differential axis J3.

[0055] As Figure 5 and Figure 6 shown, a recess 51b is provided in the second part 33b. The recess 51b recesses from the inner surface of the cover wall portion 32a, that is, the surface on the other axial side (-Y side) of the cover wall portion 32a toward the axial side (+Y side). By providing the recess 51b, the second part 33b becomes hollow. The lower end portion of the hole portion 51a opens at a portion on the axial side of the upper surface in the inner surface of the recess 51b. Thus, the inside of the hole portion 51a is connected to the inside of the recess 51b.

[0056] The recess 51b has an inner opening 51d that opens inside the gear housing 32. The inner opening 51d is the end portion on the other axial side (-Y side) of the recess 51b. In this embodiment, the inner opening 51d opens in the axial direction. Therefore, it is possible to prevent the oil 90 scattered in the vertical direction due to gear rotation from easily entering the inner opening 51d. Thus, it is possible to further suppress the accumulation of oil 90 in the first through portion 51. In this embodiment, the inner opening 51d opens on the other axial side. When viewed in the axial direction, the inner opening 51d has a substantially rectangular shape that is long in the vertical direction. In this embodiment, the opening area of the inner opening 51d is larger than the opening area of the outer opening 51c.

[0057] The lower surface of the inner surface of the recess 51b is an inclined surface 51e that is located lower as it approaches the inner opening 51d. The lower surface of the inner surface of the recess 51b is the lower surface of the inner surface of the first through-hole 51. That is, the lower surface of the inner surface of the first through-hole 51 has the inclined surface 51e. Therefore, even if the oil 90 enters the first through-hole 51, it is easy for the oil 90 to flow along the inclined surface 51e toward the inner opening 51d. Thus, it is easy for the oil 90 that has entered the first through-hole 51 to return to the inside of the gear housing 32. Therefore, it is possible to further suppress the accumulation of the oil 90 in the first through-hole 51. In addition, when an operator or the like injects the oil 90 into the gear housing 32 via the first through-hole 51, as Figure 7 shown, the oil 90 can be guided along the inclined surface 51e to the inner opening 51d. Therefore, it is possible to easily inject the oil 90 into the gear housing 32 via the first through-hole 51.

[0058] In the present embodiment, the inclined surface 51e is located lower as it faces the other side in the axial direction (-Y side). The end on the other side in the axial direction of the inclined surface 51e is located at the inner opening 51d. In the present embodiment, the inclined surface 51e is a surface that extends linearly when viewed in the front-rear direction (X-axis direction). In the present embodiment, the inclined surface 51e constitutes the entire lower surface of the inner surface of the first through-hole 51.

[0059] In the present embodiment, the entire inner opening 51d is axially provided at a position different from that of the plurality of gears, that is, the first gear 24a, the second gear 24b, the third gear 24c, and the ring gear 22a. Therefore, it is easy to suppress the oil 90 scattered in the gear housing 32 due to the rotation of the gears from entering the inner opening 51d. Thus, it is possible to further suppress the accumulation of the oil 90 in the first through-hole 51. Therefore, it is possible to further suppress the shortage of the oil 90 supplied to the respective gears and bearings housed in the gear housing 32. In the present embodiment, the entire inner opening 51d is located on the side in the axial direction (+Y side) closer to the first gear 24a, the second gear 24b, the third gear 24c, and the ring gear 22a.

[0060] As Figure 3 shown, the inner opening 51d and at least one gear have portions that are axially provided at the same position in the front-rear direction (X-axis direction). Therefore, when an operator or the like injects the oil 90 into the inside of the gear housing 32 via the first through-hole 51, it is possible to easily supply the oil 90 that has flowed into the inside of the gear housing 32 from the inner opening 51d to the at least one gear and the bearing that supports the at least one gear. Thus, before the gear device 20 is initially driven, it is possible to easily supply the oil 90 as lubricating oil to the at least one gear and the bearing.

[0061] In the present embodiment, the inner opening 51d and the second gear 24b have portions that are disposed at the same position in the front-rear direction (X-axis direction). The inner opening 51d and the third gear 24c have portions that are disposed at the same position in the front-rear direction. The inner opening 51d and the ring gear 22a have portions that are disposed at the same position in the front-rear direction. Therefore, when an operator or the like injects oil 90 into the interior of the gear housing 32 via the first through-hole 51, it is possible to easily supply the oil 90 to the second gear 24b, the third gear 24c, the ring gear 22a, and the respective bearings that support these gears.

[0062] In the case where the intermediate axis J2 is located above the central axis J1 as in the present embodiment, the second gear 24b and the third gear 24c are located on the upper side as compared with the case where the intermediate axis J2 is located at the same position as the central axis J1 in the up-down direction or below the central axis J1. Therefore, even when the gear device 20 is driven and the oil 90 in the first storage portion 32d is lifted by the ring gear 22a, it may be difficult to supply the oil 90 to the second gear 24b and the third gear 24c as compared with the first gear 24a and the ring gear 22a. However, in the present embodiment, as described above, when an operator or the like injects the oil 90 into the interior of the gear housing 32 via the first through-hole 51, it is possible to easily supply the oil 90 to the second gear 24b and the third gear 24c. Therefore, it is possible to easily supply the oil 90 to the second gear 24b and the third gear 24c before the first driving of the gear device 20. For example, when the gear device 20 is first driven, it is possible to suppress a shortage of the oil 90 in the second gear 24b and the third gear 24c. That is, it is possible to drive the gear device 20 in a state where the oil 90 is previously supplied to the second gear 24b and the third gear 24c for lubrication.

[0063] The position of the entire inner opening 51d in the front-rear direction (X-axis direction) is included in the position of the second gear 24b in the front-rear direction. The entire inner opening 51d is disposed at the same position in the front-rear direction as a part of the rear side (-X side) portion of the second gear 24b. A part of the front side (+X side) portion of the inner opening 51d is disposed at the same position in the front-rear direction as the rear end portion of the third gear 24c. The entire inner opening 51d is disposed within the range in the front-rear direction between one end and the other end in the front-rear direction of the ring gear 22a. The entire inner opening 51d is disposed at the same position in the front-rear direction as the rear end portion of the ring gear 22a.

[0064] The inner opening 51d and the bearing 25c have portions that are disposed at the same position in the front-rear direction (X-axis direction). Therefore, when an operator or the like injects oil 90 into the interior of the gear housing 32 through the first through-hole 51, the oil 90 flowing into the interior of the gear housing 32 from the inner opening 51d can be easily supplied to the bearing 25c. Thus, for example, before initially driving the gear device 20, the oil 90 can be easily supplied to the bearing 25c as lubricating oil. In the present embodiment, the front (+X side) portion of the inner opening 51d is disposed at the same position in the front-rear direction as a part of the rear (-X side) portion of the bearing 25c.

[0065] In the present embodiment, the inner opening 51d is located at a position rearward (-X side) of the intermediate axis J2 and at a position forward (+X side) of the differential axis J3. The intermediate axis J2 is the rotation axis of the second gear 24b and the third gear 24c, and the differential axis J3 is the rotation axis of the ring gear 22a. That is, in the front-rear direction (X-axis direction), the position of the inner opening 51d is the position between the rotation axes of the second gear 24b and the ring gear 22a, which are two gears arranged at intervals in the front-rear direction as rotation axes. The position of the inner opening 51d is the position between the rotation axes of the third gear 24c and the ring gear 22a, which are two gears arranged at intervals in the front-rear direction as rotation axes. Therefore, when an operator or the like injects oil 90 into the interior of the gear housing 32 through the first through-hole 51, the oil 90 can be more easily supplied to the second gear 24b, the third gear 24c, the ring gear 22a, and the bearings supporting these gears.

[0066] The inner opening 51d is located at a position above the central axis J1, the intermediate axis J2, and the differential axis J3. The inner opening 51d is located at a position below the outer opening 51c. In the present embodiment, the position of the inner opening 51d in the front-rear direction (X-axis direction) is the same as the position of the outer opening 51c in the front-rear direction.

[0067] At least a part of the inner opening 51d is located at a position above at least one gear. Therefore, when an operator or the like injects oil 90 into the interior of the gear housing 32 through the first through-hole 51, the oil 90 flowing into the interior of the gear housing 32 from the inner opening 51d can be easily supplied to the at least one gear from above. In the present embodiment, the entire inner opening 51d is located at a position above the third gear 24c. Thus, as Figure 7As shown, it is easy to supply the oil 90 flowing into the gear housing 32 from the inner opening 51d to the third gear 24c from above. In the present embodiment, the third gear 24c is located on the axial side (+Y side) with respect to the second gear 24b. Therefore, the third gear 24c is arranged closer to the cover wall portion 32a in the axial direction than the second gear 24b. Accordingly, the inner opening 51d opens in the space portion above the third gear 24c in the internal space of the gear housing 32. Thereby, the oil 90 flowing into the gear housing 32 from the inner opening 51d can be more appropriately supplied to the third gear 24c from above.

[0068] As Figure 3 shown, when viewed axially, the inner opening 51d is located above the meshing portion 24d of the third gear 24c and the ring gear 22a, which are a pair of meshing gears. Therefore, when an operator or the like injects the oil 90 into the inside of the gear housing 32 through the first through-hole 51, the oil 90 flowing into the inside of the gear housing 32 from the inner opening 51d can be easily supplied to the meshing portion 24d of the third gear 24c and the ring gear 22a.

[0069] As Figure 6 shown, in the present embodiment, at least a part of the first through-hole 51 overlaps the second gear 24b in the axial direction. Therefore, for example, compared with the case where the entire first through-hole 51 does not overlap the second gear 24b in the axial direction, the gear housing 32 can be prevented from becoming large in the direction perpendicular to the axial direction, that is, in the vertical direction or the like. In the present embodiment, the lower end of the inner opening 51d overlaps the upper part of the second gear 24b in the axial direction. In addition, in the present specification, "an object overlaps with another object in a certain direction" only needs to be set at a position where at least a part of an object overlaps at least a part of another object when viewed in a certain direction.

[0070] As Figure 3 shown, in the present embodiment, the first through-hole 51 has a groove portion 51g. The groove portion 51g connects the inside of the concave portion 51b and the inside of the bearing holding portion 35c. Thereby, in the present embodiment, the first through-hole 51 is connected to the inside of the bearing holding portion 35c. Therefore, when an operator or the like injects the oil 90 into the gear housing 32 through the first through-hole 51, the oil 90 flowing in the first through-hole 51 can be supplied to the bearing holding portion 35c. Accordingly, the oil 90 can be supplied to the bearing 25c held by the bearing holding portion 35c.

[0071] In the present embodiment, a bearing holding portion 35c that holds a bearing 25c for rotatably supporting the upper gear is located above a bearing holding portion 35a that holds a bearing 25a for rotatably supporting the lower gear. That is, in the present embodiment, the bearing holding portion 35c connected to the first through portion 51 can also be referred to as an "upper bearing holding portion" that holds the bearings 25c for rotatably supporting the second gear 24b and the third gear 24c. The rotation axis, i.e., the intermediate axis J2, of the second gear 24b and the third gear 24c is located above the rotation axis, i.e., the central axis J1, of the first gear 24a. Thus, the bearing holding portion 35c that holds the bearings 25c for rotatably supporting the second gear 24b and the third gear 24c is disposed above the bearing holding portion 35a that holds the bearing 25a for rotatably supporting the first gear 24a. Therefore, even when the gear device 20 is driven and the oil 90 in the first storage portion 32d is lifted by the ring gear 22a, it may be difficult to supply the oil 90 into the bearing holding portion 35c compared to the inside of the bearing holding portion 35a. However, in the present embodiment, since the first through portion 51 is connected to the bearing holding portion 35c, when an operator or the like injects the oil 90 into the inside of the gear housing 32 via the first through portion 51, the oil 90 can be supplied into the bearing holding portion 35c. Therefore, before driving the gear device 20, the oil 90 can be supplied to the bearing 25c held by the bearing holding portion 35c. For example, when driving the gear device 20, it is possible to suppress a shortage of the oil 90 in the bearing 25c. That is, it is possible to drive the gear device 20 in a state where the bearing 25c is lubricated by previously supplying the oil 90. At least a part of the oil 90 flowing into the bearing holding portion 35c may also flow in the bearing holding portion 35a and be supplied to the bearing 25a.

[0072] A groove portion 51g is provided on a surface on the other axial side (-Y side) of the cover wall portion 32a. The groove portion 51g is a groove that is recessed toward one axial side (+Y side) and opens on the other axial side. In the present embodiment, the groove portion 51g extends obliquely downward and forward (+X side) from the recess portion 51b. Alternatively, a hole connecting the inside of the recess portion 51b and the inside of the bearing holding portion 35c may be provided in the cover wall portion 32a instead of the groove portion 51g. The first through portion 51 may also be connected to the inside of another bearing holding portion that holds a bearing for rotatably supporting a gear. The first through portion 51 may be connected to the inside of the bearing holding portion 35a or may be connected to the inside of the bearing holding portion 35e.

[0073] The gear housing 32 has a second through-hole portion 52 that connects the inside of the gear housing 32 to the outside of the gear housing 32. The second through-hole portion 52 is a hole that axially penetrates the lid wall portion 32a. The second through-hole portion 52 is, for example, circular in shape when viewed axially. The opening portion 52a of the second through-hole portion 52 that opens to the outside of the gear housing 32 is closed by a second bolt member 42. The second bolt member 42 is, for example, a threaded member having the same shape as the first bolt member 41. The second bolt member 42 is detachably attached to the opening portion 52a. Alternatively, the second bolt member 42 may be non-detachably attached to the opening portion 52a. The opening portion 52a opens on the surface of the lid wall portion 32a on the axial side (+Y side).

[0074] The second through-hole portion 52 is provided in the lower portion of the gear housing 32. Therefore, by using the second through-hole portion 52 as an oil drain hole for draining the oil 90 inside the gear housing 32, the oil 90 stored in the first storage portion 32d of the gear housing 32 can be appropriately drained to the outside of the gear housing 32. The second through-hole portion 52 is located below the central axis J1, the intermediate axis J2, and the differential axis J3. The second through-hole portion 52 is provided at the lower end portion of the lid wall portion 32a. The second through-hole portion 52 is located below the entire ring gear 22a. The second through-hole portion 52 is located behind (-X side) the first through-hole portion 51. When viewed axially, the second through-hole portion 52 is located below the differential axis J3. The position of the second through-hole portion 52 in the front-rear direction (X-axis direction) includes the position of the differential axis J3 in the front-rear direction.

[0075] In the present embodiment, the gear housing 32 has a third through-hole portion 53 that connects the inside of the gear housing 32 to the outside of the gear housing 32. The third through-hole portion 53 is a hole that axially penetrates the lid wall portion 32a. The third through-hole portion 53 is, for example, circular in shape when viewed axially. The opening portion 53a of the third through-hole portion 53 that opens to the outside of the gear housing 32 is closed by a third bolt member 43. The third bolt member 43 is, for example, a threaded member having the same structure as the first bolt member 41. The third bolt member 43 is detachably attached to the opening portion 53a. Alternatively, the third bolt member 43 may be non-detachably attached to the opening portion 53a. The opening portion 53a opens on the surface of the lid wall portion 32a on the axial side (+Y side).

[0076] The third through-hole 53 is located below the first through-hole 51 and above the second through-hole 52. Therefore, when an operator or the like injects oil 90 into the gear housing 32 through the first through-hole 51 and discharges the oil 90 from the gear housing 32 through the second through-hole 52, it is easy to confirm the amount of the oil 90 in the gear housing 32 through the third through-hole 53. Specifically, in the case of an operator, the amount of the oil 90 in the gear housing 32 can be confirmed by visually checking the inside of the gear housing 32 through the third through-hole 53. In the case of a device performing an operation, for example, the amount of the oil 90 in the gear housing 32 can be measured through the third through-hole 53 by using a sensor, and thus the amount of the oil 90 in the gear housing 32 can be confirmed.

[0077] In the present embodiment, the third through-hole 53 is located above the central axis J1 and the differential axis J3 and below the intermediate axis J2. The third through-hole 53 is located at the rear side (-X side) of the first through-hole 51 and the second through-hole 52. The third through-hole 53 is located at the rear side of the differential axis J3.

[0078] As Figure 1 shown, the gear housing 32 has a mounting portion 34 protruding in the axial direction. The mounting portion 34 protrudes from the surface on the axial side (+Y side) of the cover wall portion 32a toward the axial side. In the present embodiment, the mounting portion 34 has a cylindrical shape. A threaded hole 34a extending from the end face on the axial side toward the other axial side (-Y side) is provided in the mounting portion 34. In the present embodiment, a plurality of mounting portions 34 are provided. When the drive device 100 is mounted on a vehicle, a part of the vehicle body is mounted on the plurality of mounting portions 34, for example. The end portion on the axial side of the mounting portion 34 is located on the axial side of the end portion on the axial side of the convex portion 33. In other words, the end portion on the axial side of the convex portion 33 is located on the other axial side of the end portion on the axial side of the mounting portion 34. Therefore, even if the convex portion 33 is provided for providing the first through-hole 51, when the drive device 100 is mounted on a vehicle, contact between the convex portion 33 and the vehicle body can be suppressed.

[0079] The control device 60 is located above the motor housing 31. The control device 60 is mounted on the motor housing 31. The control device 60 has a circuit board 60a and a housing 60b. The circuit board 60a is housed inside the housing 60b. The housing 60b has a substantially rectangular parallelepiped box shape. A part of the housing 60b and the housing main body 30a are, for example, parts of a single component. The entire housing 60b may also be separate from the housing main body 30a. The circuit board 60a is electrically connected to the stator 12. Thus, the control device 60 is electrically connected to the motor 10. An inverter circuit for supplying power to the stator 12 is provided on the circuit board 60a.

[0080] The control device 60 has connector portions 61 and 62 that project axially. In the present embodiment, the connector portions 61 and 62 project from the side facing the axial direction (+Y side) on the axial side of the housing 60b. A pair of connector portions 61 and 62 are provided at intervals in the front-rear direction (X-axis direction). The pair of connector portions 62 are located at a position rearward (-X side) of the pair of connector portions 61. Wires of external devices (not shown) are electrically connected to the respective connector portions 61 and 62.

[0081] As Figure 4 shown, the ends on the axial side (+Y side) of the connector portions 61 and 62 are located on the other axial side (-Y side) relative to the outer opening 51c. That is, in the present embodiment, the entire outer opening 51c is provided at a position different from that of the connector portions 61 and 62 in the axis perpendicular to the up-down direction. Therefore, when the pipe member 91 is connected to the outer opening 51c, it is less likely to be obstructed by the connector portions 61 and 62. Thus, the operation of injecting the oil 90 into the gear housing 32 can be easily performed. In the present embodiment, the entire outer opening 51c is provided at a position different from that of the connector portions 61 and 62 in the front-rear direction (X-axis direction) perpendicular to the up-down direction. Therefore, when the pipe member 91 is connected to the outer opening 51c, it is less likely to be obstructed by the connector portions 61 and 62. In the present embodiment, the position of the outer opening 51c in the front-rear direction is between the pair of connector portions 61 in the front-rear direction.

[0082] In addition, in this specification, "the entire outer opening is provided at a position different from that of the connector portion in the direction perpendicular to the up-down direction" means that as long as the entire outer opening is provided at a position different from that of the connector portion in at least one of the plurality of directions that can be defined as the direction perpendicular to the up-down direction. The entire outer opening 51c may be provided at a position different from that of the connector portions 61 and 62 only in either the axial direction or the front-rear direction, or may be provided at a position different from that of the connector portions 61 and 62 in a direction different from the axial direction and the front-rear direction among the directions perpendicular to the up-down direction.

[0083] Hereinafter, embodiments different from the above-described embodiments will be described. In the description of each of the following embodiments, for structures that are the same as those described in the upper part of the description of each embodiment, the description may be omitted by appropriately assigning the same reference numerals, etc. In addition, for parts corresponding to the respective parts of the structure described in the upper part of the description of each embodiment, the same names are assigned and different reference numerals are assigned to describe the points different from the above-described structure, and the description of the points that are the same as the above-described structure may be omitted. In addition, as the structure for which the description is omitted in each of the following embodiments, within a non-contradictory range, a structure that is the same as the structure described in the upper part of each embodiment can be adopted.

[0084] <Second Embodiment>

[0085] As Figure 8 shown, in the gear device 220 of the drive device 200 in the present embodiment, the convex portion 233 and the first through portion 251 provided in the convex portion 233 are located at a lower position than the convex portion 33 and the first through portion 51 in the first embodiment. In the present embodiment, the outer opening 251c of the first through portion 251 overlaps at least one of the plurality of gears in the axial direction. Therefore, it is easy to miniaturize the gear device 220 in the direction perpendicular to the axial direction, that is, the vertical direction and the front-rear direction. In the present embodiment, the outer opening 251c overlaps the second gear 24b in the axial direction. In the present embodiment, the outer opening 251c is located at a lower position than the upper end portion of the gear housing 32. Therefore, in a structure in which the control device 60 is provided on the upper side of the motor housing 31, when an operator or the like injects oil 90 into the gear housing 32 through the first through portion 251, interference between the pipe member 91 connected to the outer opening 251c and the wirings connected to the control device 60 and the connector portions 61, 62 of the control device 60 can be suppressed.

[0086] In the present embodiment, the inner opening 251d of the first through-hole 251 overlaps at least one of the plurality of gears in the axial direction. Therefore, in the direction perpendicular to the axial direction, that is, the up-and-down direction and the front-and-back direction, it is easy to make the gear device 220 more compact. In the present embodiment, the inner opening 251d overlaps the second gear 24b, the third gear 24c, and the ring gear 22a in the axial direction. The inner opening 251d overlaps the bearing 25c in the axial direction. The lower end of the inner opening 251d is located below the intermediate axis J2 and above the central axis J1 and the differential axis J3. The other structure of the first through-hole 251 is the same as the other structure of the first through-hole 51 in the first embodiment. The other structure of the gear device 220 is the same as the other structure of the gear device 20 in the first embodiment. The other structure of the drive device 200 is the same as the other structure of the drive device 100 in the first embodiment.

[0087] <Third Embodiment>

[0088] As Figure 9 shown, in the gear device 320 of the drive device 300 of the present embodiment, the convex portion 333 and the first through-hole 351 provided in the convex portion 333 are located below and in front of (+X side) the convex portion 233 and the first through-hole 251 of the second embodiment. In the present embodiment, the outer opening 351c of the first through-hole 351 overlaps the first gear 24a in the axial direction. Therefore, similarly to the second embodiment, the gear device 320 can be miniaturized in the direction perpendicular to the axial direction, that is, the up-and-down direction and the front-and-back direction. When viewed along the axial direction, the outer opening 351c is located below the central axis J1.

[0089] In the present embodiment, the inner opening 351d of the first through-hole 351 does not overlap any gear in the axial direction. When viewed along the axial direction, the inner opening 351d is located below the central axis J1. The other structure of the first through-hole 351 is the same as the other structure of the first through-hole 51 in the first embodiment. The other structure of the gear device 320 is the same as the other structure of the gear device 20 in the first embodiment. The other structure of the drive device 300 is the same as the other structure of the drive device 100 in the first embodiment.

[0090] <Fourth Embodiment>

[0091] As Figure 10As shown, in the gear unit 420 of the drive unit 400 of the present embodiment, the gear housing 432 has a cylindrical portion 36a, first ribs 437a, 437b, and a second rib 437c. The cylindrical portion 36a projects axially forward from the peripheral portion of the through hole 36 in the axially forward (+Y side) surface of the cover wall portion 32a. The cylindrical portion 36a is cylindrical with the differential axis J3 as the center.

[0092] The first ribs 437a, 437b and the second rib 437c are provided on the axially forward (+Y side) surface of the cover wall portion 32a. The first ribs 437a, 437b are substantially annular ribs surrounding the differential axis J3. In the radial direction centered on the differential axis J3, the first ribs 437a, 437b are located outside the cylindrical portion 36a. In the radial direction centered on the differential axis J3, the first rib 437b is located outside the first rib 437a. A third through portion 53 and a third bolt member 43 are provided in the middle of the first rib 437a. A convex portion 433 and a first through portion 451 are provided in the middle of the first rib 437b.

[0093] The second rib 437c is a rib that extends linearly outward from the cylindrical portion 36a in the radial direction centered on the differential axis J3. A plurality of the second ribs 437c are provided at intervals in the circumferential direction centered on the differential axis J3. The plurality of second ribs 437c are arranged at equal intervals over the entire circumference in the circumferential direction centered on the differential axis J3. The plurality of second ribs 437c intersect with the first ribs 437a. The outer end of one of the plurality of second ribs 437c is connected to the convex portion 433. The outer ends of the remaining second ribs 437c are connected to the first rib 437b. The second rib 437c connected to the convex portion 433 is the second rib 437c that extends rearward (-X side) from the cylindrical portion 36a.

[0094] In the present embodiment, the convex portion 433 and the first through portion 451 provided in the convex portion 433 are located at a position rearward (-X side) of the differential axis J3. The convex portion 433 and the first through portion 451 are provided at the rear end of the gear housing 432. One of the first rib 437b and the plurality of second ribs 437c is connected to the convex portion 433. Therefore, the rigidity of the convex portion 433 can be improved. Therefore, it is possible to suppress the deformation of the outer opening 451c of the first through portion 451 provided in the convex portion 433, and it is possible to suppress the difficulty of connecting the pipe member 91 to the outer opening 451c.

[0095] In the present embodiment, the outer opening portion 451c overlaps the ring gear 22a in the axial direction. Thus, similar to the second embodiment, it is easy to miniaturize the gear device 420 in the direction perpendicular to the axial direction, i.e., the up-and-down direction and the front-and-back direction. The clearance 32e between the radially outer surface of the ring gear 22a and the radially inner surface 32c of the gear housing 432 overlaps the outer opening portion 451c in the axial direction. The radially inner surface 32c is the inner peripheral surface of the gear peripheral wall portion 32b.

[0096] The inner opening portion 451d overlaps the clearance 32e between the radially outer surface of the ring gear 22a and the radially inner surface 32c of the gear housing 432 in the axial direction. Therefore, when an operator or the like injects the oil 90 into the gear housing 432 through the first through-hole portion 451, it is easy to supply the oil 90 flowing into the interior of the gear housing 432 from the inner opening portion 451d to the tooth portion of the ring gear 22a. In addition, in this specification, the "radially outer surface of the gear" refers to the outer surface of the gear in the radial direction centered on the rotation axis of the gear, including the front end surface of the tooth portion of the gear. That is, the radially outer surface of the ring gear 22a refers to the outer surface of the ring gear 22a in the radial direction centered on the differential axis J3, including the front end surface of the tooth portion of the ring gear 22a. In the present embodiment, the inner opening portion 451d overlaps the ring gear 22a in the axial direction. The lower end portion of the inner opening portion 451d is located at a position lower than the central axis J1 and the differential axis J3.

[0097] The other structures of the first through-hole portion 451 are the same as those of the first through-hole portion 51 in the first embodiment. The other structures of the gear device 420 are the same as those of the gear device 20 in the first embodiment. The other structures of the drive device 400 are the same as those of the drive device 100 in the first embodiment.

[0098] <Fifth Embodiment>

[0099] As Figure 11 shown, the gear device 520 of the drive device 500 in the present embodiment has a second storage portion 570. The second storage portion 570 is a storage portion disposed inside the gear housing 532 and separated upward from the bottom of the gear housing 532. The second storage portion 570 can store the oil 90 inside. In the present embodiment, the second storage portion 570 is in a groove shape that opens upward. In addition, the second storage portion 570 may be of any shape as long as it can store the oil 90 inside. The second storage portion 570 may also be in a shape that opens in a direction perpendicular to the up-and-down direction. For example, a part of the oil 90 lifted from the first storage portion 32d by the ring gear 22a and the like enters the interior of the second storage portion 570.

[0100] The second storage portion 570 is located above the first storage portion 32d. In the present embodiment, the second storage portion 570 is located at a position above the plurality of gears, that is, the first gear 24a, the second gear 24b, the third gear 24c, and the ring gear 22a. The second storage portion 570 is connected to the gear housing 532. At least a part of the second storage portion 570 and the gear cover 30c are parts of a single component, for example. Alternatively, the entire second storage portion 570 may be separate from the gear housing 532. The second storage portion 570 has a bottom wall portion 571 and a pair of side wall portions 572. The pair of side wall portions 572 project upward from both edge portions of the bottom wall portion 571 in the front-rear direction (X-axis direction).

[0101] In the present embodiment, connection flow path portions 538c and 538e are provided in the gear housing 532. The connection flow path portions 538c and 538e are provided in the gear cover 30c, for example. The connection flow path portion 538c connects the inside of the second storage portion 570 to the inside of the bearing holding portion 35c. The connection flow path portion 538c extends obliquely downward and forward (+X side) from the bottom wall portion 571 and is connected to the inside of the bearing holding portion 35c. A part of the oil 90 in the second storage portion 570 flows in the connection flow path portion 538c and flows into the bearing holding portion 35c. Thereby, the oil 90 is supplied to the bearing 25c. The connection flow path portion 538e connects the inside of the second storage portion 570 to the inside of the bearing holding portion 35e. The connection flow path portion 538e extends downward from the bottom wall portion 571 and is connected to the inside of the bearing holding portion 35e. A part of the oil 90 in the second storage portion 570 flows in the connection flow path portion 538e and flows into the bearing holding portion 35e. Thereby, the oil 90 is supplied to the bearing 25e. In addition, at least a part of the oil 90 that has flowed into the inside of the bearing holding portion 35c from the second storage portion 570 may also flow into the bearing holding portion 35a that holds the bearing 25a that rotatably supports the first gear shaft 23a and supply the oil 90 to the bearing 25a.

[0102] In the present embodiment, the first through portion 551 is connected to the second storage portion 570. Therefore, when an operator or the like injects the oil 90 into the gear housing 532 via the first through portion 551, the oil 90 flowing in the first through portion 551 can flow into the second storage portion 570. Thereby, when an operator or the like injects the oil 90 into the gear housing 532 via the first through portion 551, the oil 90 can flow from the second storage portion 570 to the portion connected to the second storage portion 570. Specifically, in the present embodiment, the oil 90 can flow from the second storage portion 570 to the connection flow path portions 538c and 538e. Thereby, when an operator or the like injects the oil 90 into the gear housing 532 via the first through portion 551, the oil 90 can be supplied to the bearings 25c and 25e held by the bearing holding portions 35c and 35e.

[0103] In the present embodiment, the first through portion 551 and the second storage portion 570 are arranged in the front-rear direction (X-axis direction) perpendicular to both the axial direction and the up-down direction. Therefore, even if the second storage portion 570 is provided, it is possible to suppress the enlargement of the gear device 520 in the axial direction and the up-down direction. The first through portion 551 is located on the front side (+X side) of the second storage portion 570. The first through portion 551 is provided, for example, in the cover wall portion 32a.

[0104] The first through portion 551 has a first hole portion 551a and a second hole portion 551b. The first hole portion 551a extends downward from the upper surface of the gear housing 532. The upper end portion of the first hole portion 551a is an outer opening portion 551c that opens upward. The second hole portion 551b extends obliquely backward (-X side) and downward from the lower end portion of the first hole portion 551a. The rear end portion of the second hole portion 551b is connected to the side wall portion 572 on the front side (+X side) among the pair of side wall portions 572. The rear end portion of the second hole portion 551b is an inner opening portion 551d that opens inside the second storage portion 570. In the present embodiment, the inner opening portion 551d opens at the rear side. The lower surface of the inner surface of the second hole portion 551b is the lower surface of the inner surface of the first through portion 551, and is an inclined surface 551e that is located lower as it approaches the inner opening portion 551d. The inclined surface 551e is located lower as it faces the rear side. Through the inclined surface 551e, the oil 90 flowing into the first through portion 551 from the outer opening portion 551c can be appropriately guided into the second storage portion 570.

[0105] The other structures of the first through portion 551 are the same as the other structures of the first through portion 51 in the first embodiment. The other structures of the gear device 520 are the same as the other structures of the gear device 20 in the first embodiment. The other structures of the drive device 500 are the same as the other structures of the drive device 100 in the first embodiment.

[0106] <Sixth Embodiment>

[0107] As Figure 12 shown, in the gear device 620 of the drive device 600 in the present embodiment, a mounting hole 632f penetrating the cover wall portion 32a in the front-rear direction (X-axis direction) is provided in the cover wall portion 32a of the gear housing 632. The mounting hole 632f is provided in the lower portion of the cover wall portion 32a. The rear end portion (-X side) of the mounting hole 632f is a suction port 632e that opens on the inner surface of the gear housing 632. The suction port 632e opens on the inner surface of the cover wall portion 32a, that is, the rear surface. The suction port 632e opens inside the first storage portion 32d.

[0108] The gear device 620 has a pump 680 that sucks oil 90 into the gear housing 632 via a suction port 632e. The pump 680 is an electric pump. The pump 680 is mounted on the outer surface of the cover wall portion 32a, that is, the front side (+X side) surface. The pump 680 has a connection portion 681 that is inserted into the suction port 632e from the outside of the gear housing 632. The connection portion 681 is in the shape of a cylinder that opens at the rear side (-X side).

[0109] In the present embodiment, the convex portion 633 and the first through portion 651 are located above the pump 680. The convex portion 633 is the same as the convex portion 33 of the first embodiment except for the difference in position. The first through portion 651 is the same as the first through portion 51 of the first embodiment except for the difference in position. The inner opening portion 651d of the first through portion 651 is located above the suction port 632e on the inner surface of the cover wall portion 32a, that is, the rear side (-X side) surface. In the present embodiment, the inner opening portion 651d and the suction port 632e are arranged side by side. Therefore, when an operator or the like injects oil 90 into the gear housing 632 via the first through portion 651, the oil 90 flowing into the gear housing 632 from the inner opening portion 651d can be made to flow near the suction port 632e. Thereby, for example, when the pump 680 is initially driven, it is possible to suppress the shortage of oil 90 around the suction port 632e and suppress the idling of the pump 680.

[0110] The distance between the inner opening portion 651d and the suction port 632e is smaller than the vertical dimension of the inner opening portion 651d. The distance between the inner opening portion 651d and the suction port 632e is preferably less than the inner diameter of the suction port 632e. Other structures of the gear device 620 are the same as those of the gear device 20 in the first embodiment. Other structures of the drive device 600 are the same as those of the drive device 100 in the first embodiment.

[0111] The present invention is not limited to the above-described embodiments, and within the scope of the technical idea of the present invention, other structures and other methods can also be adopted. The first through portion has an inner opening portion and an outer opening portion, and as long as the inside of the gear housing is connected to the outside of the gear housing, it can have any structure. The outer opening portion that opens to the outside of the gear housing can have any structure as long as it is closed by the first bolt member and is provided in a position different from that of the plurality of gears in the first direction. In the above-described second embodiment, the outer opening portion 251c can overlap the third gear 24c in the axial direction instead of the second gear 24b, or can overlap both the second gear 24b and the third gear 24c in the axial direction. The inner opening portion that opens to the inside of the gear housing can have any structure. The inner opening portion can be provided at any position. The shape of the outer opening portion and the shape of the inner opening portion are not particularly limited.

[0112] The directions in which the outer opening and the inner opening open are not particularly limited. The outer opening may open in the front-rear direction (X-axis direction) of the above-described embodiment, or may open in the axial direction (Y-axis direction) of the above-described embodiment. The inner opening may open in the up-down direction, or may open in the front-rear direction (X-axis direction) of the above-described embodiment.

[0113] When an inclined surface is provided on the lower surface of the inner surface of the first through-hole portion, the lower surface of the inner surface of the first through-hole portion may also have a surface other than the inclined surface. The inclined surface provided on the lower surface of the inner surface of the first through-hole portion may be inclined in any direction as long as it is located on the lower side as it approaches the inner opening.

[0114] The first through-hole portion may be a through-hole portion for any purpose. The first through-hole portion may also be a through-hole portion used as an oil drain hole. The first through-hole portion may also be a through-hole portion for the same purpose as the third through-hole portion 53 in the first embodiment described above. A plurality of first through-hole portions may also be provided. The first through-hole portion may be provided at any part of the gear housing. The first through-hole portion may also be provided in the part of the gear housing 32 of the first embodiment described above that is constituted by the housing main body 30a. The second through-hole portion may be provided in the lower wall portion of the gear housing, or may be provided in the side wall portion 32f of the first embodiment described above. The third through-hole portion may also be provided in the side wall portion 32f of the first embodiment described above. The second through-hole portion and the third through-hole portion may not be provided.

[0115] The gear device may also have a pressure adjustment portion provided in the gear housing. The pressure adjustment portion may have any structure as long as it can adjust the pressure inside the gear housing. The pressure adjustment portion may be a ventilation valve or a ventilation filter. For example, in the first embodiment described above, the pressure adjustment portion may also be provided at a position on the front side (+X side) of the center axis J1 with respect to the differential axis J3 in the front-rear direction (X-axis direction), that is, on the side farther from the ring gear 22a than the first through-hole portion 51. According to this structure, the pressure adjustment portion can be arranged to be farther from the ring gear 22a than the first through-hole portion 51 in the front-rear direction. Thereby, the oil 90 lifted by the ring gear 22a is less likely to reach the pressure adjustment portion. Therefore, leakage of the oil 90 to the outside of the gear housing 32 via the pressure adjustment portion can be suppressed.

[0116] When the pressure adjustment portion is provided in the gear housing, for example, the first through-hole portion 51 and the pressure adjustment portion in the first embodiment described above may also have a part provided at the same position in the up-down direction. According to this structure, enlargement of the gear device 20 in the up-down direction can be suppressed.

[0117] The first direction in which the rotation axes of the plurality of gears extend only needs to be a direction perpendicular to the vertical direction, and is not particularly limited. It may also be a direction different from the axial direction of the motor connected to the gear device. For example, the first direction in which the rotation axes of the plurality of gears extend may also be the front-rear direction (X-axis direction) in the above-described embodiment. The fluid housed in the gear housing may also be a fluid other than oil such as water. In the above-described embodiment, the intermediate axis J2 may also be located at a position lower than the central axis J1.

[0118] The uses of the gear device and the drive device are not particularly limited. For example, the drive device may be mounted on a vehicle for uses other than rotating an axle, or may be mounted on a device other than a vehicle.

[0119] In addition, the present technology may adopt the following structure.

[0120] (1) A gear device having: a plurality of gears that rotate about a rotation axis extending in a first direction perpendicular to the vertical direction; and a gear housing that houses the plurality of gears therein, the gear housing having a first through-hole that connects the inside of the gear housing to the outside of the gear housing, the first through-hole having: an inner opening that opens inside the gear housing; and an outer opening that opens outside the gear housing, the outer opening being closed by a first bolt member, and the entire outer opening being provided at a position different from the plurality of gears in the first direction.

[0121] (2) The gear device according to (1), wherein the outer opening opens upward.

[0122] (3) The gear device according to (1) or (2), wherein the inner opening opens in the first direction.

[0123] (4) The gear device according to (3), wherein the lower surface of the inner surface of the first through-hole has an inclined surface that is located lower as it approaches the inner opening.

[0124] (5) The gear device according to any one of (1) to (4), wherein the inner opening and at least one of the gears have a portion provided at the same position in a second direction perpendicular to both the first direction and the vertical direction.

[0125] (6) The gear device according to any one of (1) to (5), wherein the gear device has a bearing that supports the gear so as to be rotatable, and the inner opening and the bearing have a portion provided at the same position in a second direction perpendicular to both the first direction and the vertical direction.

[0126] (7) The gear device according to any one of (1) to (6), wherein the plurality of gears include two gears whose rotation axes are arranged at intervals in a second direction perpendicular to both the first direction and the up-and-down direction, and in the second direction, the position of the inner opening is the position between the rotation axes of the two gears.

[0127] (8) The gear device according to any one of (1) to (7), wherein the outer opening overlaps at least one of the plurality of gears in the first direction.

[0128] (9) The gear device according to any one of (1) to (8), wherein at least a part of the inner opening is located at a position above at least one of the gears.

[0129] (10) The gear device according to (9), wherein the gear device has: a reduction device; and a differential device connected to the reduction device, the reduction device has: a gear shaft extending in the first direction; a first gear as the gear provided on the gear shaft; a second gear as the gear meshing with the first gear; and a third gear as the gear rotating around the same rotation axis as the second gear, the whole of the inner opening is located at a position above the third gear, the outer diameter of the second gear is larger than the outer diameter of the third gear, and at least a part of the first through portion overlaps with the second gear in the first direction.

[0130] (11) The gear device according to any one of (1) to (10), wherein the gear device has a storage portion disposed inside the gear housing and separated upward from the bottom of the gear housing, the storage portion is open upward, and the first through portion is connected to the storage portion.

[0131] (12) The gear device according to (11), wherein the first through portion and the storage portion are arranged in a second direction perpendicular to both the first direction and the up-and-down direction.

[0132] (13) The gear device according to any one of (1) to (12), wherein the whole of the inner opening is arranged at a position different from the plurality of gears in the first direction.

[0133] (14) The gear device according to any one of (1) to (13), wherein the plurality of gears include a pair of meshing gears, and when viewed in the first direction, the inner opening is located above the meshing portion of the pair of gears with each other.

[0134] (15) The gear device according to any one of (1) to (14), wherein the inner opening overlaps with the gap between the radially outer surface of the gear and the radially inner surface of the gear housing in the first direction.

[0135] (16) The gear device according to any one of (1) to (15), wherein the gear device has a pump that sucks the fluid in the gear housing through a suction port opening on the inner surface of the gear housing, and the inner opening is arranged in alignment with the suction port.

[0136] (17) The gear device according to any one of (1) to (16), wherein the gear housing has a second through portion that connects the inside of the gear housing to the outside of the gear housing, and the opening portion of the second through portion that opens to the outside of the gear housing is closed by a second bolt member, and the second through portion is provided in the lower side portion of the gear housing.

[0137] (18) The gear device according to (17), wherein the gear housing has a third through portion that connects the inside of the gear housing to the outside of the gear housing, and the opening portion of the third through portion that opens to the outside of the gear housing is closed by a third bolt member, and the third through portion is located at a position lower than the first through portion and at a position higher than the second through portion.

[0138] (19) The gear device according to any one of (1) to (18), wherein the gear housing has a bearing holding portion that holds a bearing for rotatably supporting the gear, and the first through portion is connected to the inside of the bearing holding portion.

[0139] (20) The gear device according to (19), wherein the plurality of gears include a lower gear; and an upper gear, and the rotation axis of the upper gear is located at a position higher than that of the lower gear, and the bearing holding portion includes an upper bearing holding portion that holds an upper bearing for rotatably supporting the upper gear, and the first through portion is connected to the inside of the upper bearing holding portion.

[0140] (21) A drive device, comprising: the gear device according to any one of (1) to (20); and a motor connected to the gear device.

[0141] (22) The drive device according to (21), wherein the drive device has a control device electrically connected to the motor, the control device has a connector portion protruding in the first direction, and the entirety of the outer opening portion is provided at a position different from the connector portion in a direction perpendicular to the vertical direction.

[0142] As described above, the structures and methods described in this specification can be appropriately combined within a range where they do not conflict with each other.

Claims

1. A gear device, comprising: a plurality of gears that rotate about a rotation axis extending in a first direction that is perpendicular to the up-down direction; and a gear housing that accommodates the plurality of gears therein, The gear housing has a first through portion connecting the inside of the gear housing and the outside of the gear housing. The first through portion has: an inner opening portion that opens inside the gear housing; and an outer opening portion, which opens outside the gear housing, The outer opening is closed by a first plug member. The entire outer opening portion is provided at a position different from the plurality of gears in the first direction.

2. The gear device according to claim 1, wherein: The outer opening portion is opened at the upper side.

3. The gear device according to claim 1, wherein: The inner opening portion opens in the first direction.

4. The gear device according to claim 3, wherein: A surface located on the lower side of the inner surface of the first penetration portion has an inclined surface located on the lower side as approaching the inner opening.

5. The gear device according to claim 1, wherein: The inner opening and at least one of the gears have portions provided at the same position as each other in a second direction perpendicular to both the first direction and the up-down direction.

6. The gear device according to claim 1, wherein: The gear device includes a bearing that rotatably supports the gear. The inner opening portion and the bearing have portions provided at the same position as each other in a second direction perpendicular to both the first direction and the up-down direction.

7. The gear device according to claim 1, wherein: The plurality of gears include two gears whose rotation axis is spaced apart in a second direction perpendicular to both the first direction and the up-down direction. In the second direction, the position of the inner opening portion is a position between the rotation axis lines of the two gears.

8. The gear device according to claim 1, wherein: The outer opening portion overlaps with at least one of the plurality of gears in the first direction.

9. The gear device according to claim 1, wherein: At least a portion of the inner opening is located above at least one of the gears.

10. The gear device according to claim 9, wherein: The gear unit has: Speed ​​reduction device; as well as a differential device connected to the reduction gear, The deceleration device comprises: a gear shaft extending along the first direction; A first gear as the gear, which is arranged on the gear shaft; A second gear as the gear, which meshes with the first gear; as well as The third gear as the gear rotates around the same rotation axis as the second gear, The entire inner opening is located above the third gear. The outer diameter of the second gear is larger than the outer diameter of the third gear. At least a portion of the first penetration portion overlaps with the second gear in the first direction.

11. The gear device according to claim 1, wherein: The gear device includes a storage portion disposed inside the gear housing and spaced apart from the bottom of the gear housing and upward. The storage portion is open at the upper side, The first through portion is connected to the storage portion.

12. The gear arrangement according to claim 11, wherein: The first penetration portion and the storage portion are arranged side by side in a second direction perpendicular to both the first direction and the up-down direction.

13. The gear device according to claim 1, wherein: The entire inner opening portion is provided at a position different from the plurality of gears in the first direction.

14. The gear arrangement according to claim 1, wherein: The plurality of gears include a pair of gears meshing with each other, When viewed along the first direction, the inner opening is located above a meshing portion between the pair of gears.

15. The gear arrangement according to claim 1, wherein: The inner opening portion overlaps with a gap between a radially outer surface of the gear and a radially inner surface of the gear housing in the first direction.

16. The gear arrangement of claim 1, wherein: The gear device includes a pump that sucks fluid in the gear housing through a suction port opened on the inner surface of the gear housing. The inner opening portion and the suction port are arranged in parallel.

17. The gear arrangement of claim 1, wherein: The gear housing has a second through portion connecting the inside of the gear housing and the outside of the gear housing. The opening of the second through-portion that opens to the outside of the gear housing is closed by a second plug member. The second penetration portion is provided at a lower portion of the gear housing.

18. The gear arrangement according to claim 17, wherein: The gear housing has a third through portion connecting the inside of the gear housing and the outside of the gear housing. The opening of the third through-portion that opens to the outside of the gear housing is closed by a third plug member. The third penetration portion is located below the first penetration portion and above the second penetration portion.

19. The gear arrangement of claim 1, wherein: The gear housing includes a bearing holding portion for holding a bearing that rotatably supports the gear. The first penetration portion is connected to the interior of the bearing holding portion.

20. The gear arrangement according to claim 19, wherein: The plurality of gears include: lower side gear; and an upper gear, the rotation axis of which is located above the lower gear, The bearing holding portion includes an upper bearing holding portion that holds an upper bearing that rotatably supports the upper gear. The first penetration portion is connected to the interior of the upper bearing holding portion.

21. A driving device, comprising: A gear arrangement as claimed in any one of claims 1 to 20; and A motor is connected to the gear device.

22. The driving device according to claim 21, wherein: The drive device has a control device electrically connected to the motor. The control device has a connector portion protruding along the first direction, The entire outer opening portion is provided at a position different from that of the connector portion in a direction perpendicular to the up-down direction.

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