DRIVE DEVICE

Abstract

One aspect of a drive device of the present invention comprises a drive force transmission section coupled to the electric rotary machine on one axially inclined side, and a housing that accommodates the electric rotary machine and the drive force transmission section. The housing has a gear cover located on one axially inclined side of the drive force transmission section and supporting a shaft of the drive force transmission section. The gear cover has a coupling section having a coupling axis extending axially at its center point and projecting axially to one side. The coupling section has a vertex section through which the coupling axis passes and an inclined section widening from the vertex section to a radially outer side.The inclined section slopes increasingly from the apex towards the radially outer side towards the axially opposite side. The angle of inclination with respect to a plane orthogonal to the dome axis increases from the apex towards the radially outer side.

Description

TECHNICAL FIELD

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

[0002] This application claims priority from Japanese Application No. 2022-105974, filed on June 30, 2022, the contents of which are hereby incorporated into the present subject matter. GENERAL STATE OF THE ART

[0003] A vehicle drive device is known from the prior art, comprising an electric rotary machine, a drive transmission section coupled to the electric rotary machine, and a housing in which they are housed. In this structure, the housing supports a shaft of the drive transmission section. For example, Patent Document 1 discloses a structure in which a bearing rotatably supporting the shaft of a transmission mechanism is held on a wall portion of a device housing. PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0004] Patent Document 1: JP 2010-246180 A SUMMARY OF THE INVENTION OBJECT OF THE PRESENT INVENTION

[0005] Due to the meshing of the gears, vibration of the drive transmission section occurs, among other things. Therefore, there is a risk that the transmission cover supporting the drive transmission section will vibrate due to the vibration of the drive transmission section, causing diaphragm vibration. To prevent diaphragm vibration on the transmission cover, the strength of the transmission cover must be increased, but measures such as increasing the thickness of the transmission cover pose the problem of increasing the weight of the drive device.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a drive device in which the strength of the transmission cover can be increased without increasing the weight of the transmission cover. MEANS FOR SOLVING THE TASK

[0007] One aspect of a drive device of the present invention includes a drive force transmitting portion coupled to the rotary electric machine on one axial side of the above-described rotary electric machine, and a housing that houses the rotary electric machine and the drive force transmitting portion. The housing includes a gear cover located on the axial side of the drive force transmitting portion and supporting a shaft of the drive force transmitting portion. The gear cover includes a coupling portion having a coupling axis extending in the axial direction as its center and projecting toward the one axial side. The coupling portion includes an apex portion through which the coupling axis passes, and a slant portion extending from the apex portion to a radially outer side.The inclined section slopes progressively from the apex section toward the radially outer side to the other side in the axial direction. The angle of inclination relative to a plane orthogonal to the coupling axis becomes progressively larger from the apex section toward the radially outer side. EFFECT OF THE INVENTION

[0008] According to one aspect of the present invention, a drive device can be provided in which the strength of the transmission cover can be increased without increasing the weight of the transmission cover. BRIEF DESCRIPTION OF THE CHARACTERS Fig. 1 is a schematic overview view of a drive device of an embodiment. Fig. 2 is a front view of a gear cover of the embodiment. Fig. 3 is a perspective view of the gear cover of the embodiment. Fig. 4 is a schematic sectional view of a first dome portion of the gear cover of the embodiment. Fig. 5 is a schematic sectional view of a second dome portion of the gear cover of the embodiment. Fig. 6 is a schematic sectional view of a third dome portion of the gear cover of the embodiment. EMBODIMENT OF THE INVENTION

[0009] An embodiment of a drive device of the present invention will be described below with reference to the figures.

[0010] In the following description, the description will be made by defining the vertical direction based on positional relationships when the drive device of the embodiment shown in the figures is installed on a vehicle standing on a horizontal road surface. In the figures, an XYZ coordinate system is shown as the three-dimensional orthogonal coordinate system for convenience. In the XYZ coordinate system, the Z-axis direction is the vertical direction. The +Z side is the upper side in the vertical direction, and the -Z side is the lower side in the vertical direction. In the following description, the upper side in the vertical direction is referred to as the "upper side" for short, and the lower side in the vertical direction is referred to as the "lower side" for short. The X-axis direction is a direction orthogonal to the Z-axis direction and is the front-rear direction of the vehicle on which the drive device is installed.In the following embodiment, the +X side is the front of the vehicle, and the -X side is the rear of the vehicle. The Y-axis direction is a direction orthogonal to both the X-axis direction and the Z-axis direction and is the left-right direction of the vehicle, i.e., the vehicle transverse direction. In the following embodiment, the +Y side is the left side of the vehicle, and the -Y side is the right side of the vehicle. The front-rear direction and the left-right direction are horizontal directions orthogonal to the vertical direction.

[0011] A central axis J shown in the individual figures for ease of illustration extends in the Y-axis direction, i.e., in the left-right direction of the vehicle. Unless otherwise stated, in the following description, a direction parallel to the central axis J is simply referred to as the "axial direction," a radial direction with the central axis J as the center is referred to as the "radial direction," and a circumferential direction around the central axis J, i.e., a direction around the central axis J, is referred to as the "circumferential direction." Also, in the following description, with regard to the axial direction running along the central axis J, the +Y side is also simply referred to as one side in the axial direction, and the -Y side is also simply referred to as the other side in the axial direction.

[0012] The up-down direction, the upper side, and the lower side are merely terms used to describe the arrangement relationships of the individual sections. The arrangement relationships may also be other than those indicated by these terms. The effect of the embodiment can also be achieved if the directions described as one side in the axial direction and the other side in the axial direction are interchanged.

[0013] Fig. 1 is a schematic overview view of a drive device 1 of an embodiment.

[0014] The drive device 1 is installed in a vehicle driven by an engine as a driving power source, such as a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHV), or an electric vehicle (EV), among others.

[0015] The drive device 1 includes an electric rotary machine 2, a drive force transmission section 3, a housing 80 that houses the electric rotary machine 2 and the drive force transmission section 3, a fluid O circulating in the housing 80, a cooler 9 that cools the fluid O, and a pump 8 that conveys the fluid O by pressure. (Electric rotary machine)

[0016] In the present embodiment, the electric rotary machine 2 is an internal rotor type motor. The electric rotary machine 2 of the present embodiment is also, for example, a three-phase AC motor. The electric rotary machine 2 simultaneously functions as an electric motor and a generator. The electric rotary machine 2 includes a rotor 20 and a stator 30.

[0017] The rotor 20 rotates around the central axis J. The torque of the rotor 20 is transmitted to the drive force transmission device 3. The rotor 20 includes a motor shaft 21, a rotor core 24, and a rotor magnet (not shown) fixed to the rotor core. The rotor core 24 is fixed to the outer peripheral surface of the motor shaft 21.

[0018] The motor shaft 21 extends along the central axis J. In the present embodiment, the motor shaft 21 is a hollow shaft. The motor shaft 21 rotates around the central axis J. The motor shaft 21 is connected to the rotor 20 inside the first receiving portion 80A. The motor shaft 21 is connected to the drive force transmission portion 3 inside the second receiving portion 80B.

[0019] The stator 30 surrounds the rotor 20 from the radially outer side. The stator 30 faces the rotor 20 with a gap therebetween. The stator 30 includes a stator core 32 and coils 31. The stator 30 is held on the housing 80. The stator core 32 includes a plurality of magnetic pole teeth (not shown) located radially inward of an inner peripheral surface of an annular yoke. A coil wire is arranged between the magnetic pole teeth. The coil wire forms coils 31 in the spaces between adjacent magnetic pole teeth. (Drive transmission section)

[0020] The driving force transmission section 3 is a driving force transmission mechanism including a plurality of gears 41, 42, 43, 51 and a plurality of shafts 44, 45, 50a, 55. The driving force transmission section 3 is coupled to the rotating electric machine 2 on the axial direction side (+Y side) of the rotating electric machine 2. The driving force transmission section 3 transmits the driving force of the rotating electric machine 2 and outputs it to the output shaft 55.

[0021] The drive force transmission section 3 includes a reduction device 4, a differential device 5, and a plurality of bearings including a first bearing 6A, a second bearing 6B, a third bearing 6C, a fourth bearing 6D, and a fifth bearing 6E. The reduction device 4 reduces the speed of the electric rotating machine 2 and serves to increase the torque output by the electric rotating machine 2 according to the reduction ratio. The reduction device 4 is connected to the motor shaft 21. The reduction device 4 transmits the torque output by the electric rotating machine 2 to the differential device 5.

[0022] The reduction device 4 includes a first shaft 44, a first gear 41, a second shaft 45, and a second gear 42 and a third gear 43 fixed to the second shaft 45. The torque output from the electric rotary machine 2 is transmitted to a ring gear 51 of the differential device 5 via the first shaft 44, the first gear 41, the second gear 42, and the third gear 43. The gear ratios of the individual gears, the number of gears, etc., can be changed in various ways as needed.

[0023] The first shaft 44 extends in the axial direction with a first axis J1 as its center. The first shaft 44 rotates about the first axis J1. The first axis J1 is an imaginary axis extending parallel to the central axis J. In the present embodiment, the first axis J1 is arranged coaxially on the central axis J.

[0024] The first shaft 44 is a hollow shaft. The first shaft 44 is connected to the motor shaft 21 at the end portion on the other side in the axial direction (Y side). The first shaft 44 and the motor shaft 21 are coupled to each other, for example, by spline engagement. The hollow portion of the first shaft 44 is connected to the hollow portion of the motor shaft 21.

[0025] The coupling portion of the first shaft 44 and the motor shaft 21 is disposed inside a first through-hole 88a of a partition wall portion 88. Although not shown, a pair of bearings is held on the inner peripheral surface of the first through-hole 88a, one of the two bearings supporting the first shaft 44 and the other supporting the motor shaft 21.

[0026] An end portion 44a of the first shaft 44 on one side in the axial direction (+Y-side) is rotatably supported on a gear cover 82 via the first bearing 6A. The first bearing 6A thus supports the first shaft 44.

[0027] The first gear 41 is fixed to the outer peripheral surface of the first shaft 44. The first gear 41 rotates together with the first shaft 44 about the first axis J1. In other words, the first shaft 44 rotates together with the first gear 41 about the first axis J1.

[0028] The second shaft 45 extends in the axial direction with a second axis J2 as its center. The second shaft 45 is a hollow shaft. The second axis J2 is an imaginary axis extending parallel to the first axis J1. The second shaft 45 rotates about the second axis J2. An end portion 45a of the second shaft 45 on one side in the axial direction (+Y side) is rotatably supported on the gear cover 82 via the second bearing 6B. An end portion 45b of the second shaft 45 on the other side in the axial direction (-Y side) is supported on the partition wall portion 88 via the third bearing 6C. The second bearing 6B and the third bearing 6C thus support the second shaft 45.

[0029] The second gear 42 and the third gear 43 are arranged side by side in the axial direction. The second gear 42 and the third gear 43 are fixed to the outer peripheral surface of the second shaft 45. The second gear 42 and the third gear 43 rotate together with the second shaft 45 about the second axis J2. The second shaft 45 thus rotates together with the second gear 42 and the third gear 43 about the second axis J2. The second gear 42 is meshed with the first gear 41. The third gear 43 is meshed with the ring gear 51 of the differential device 5.

[0030] The differential device 5 is a device for transmitting the torque output from the electric rotary machine 2 to the wheels of a vehicle. The differential device 5 serves to absorb speed differences between the left and right wheels while the vehicle is traveling and to transmit equal torque to a pair of output shafts 55.

[0031] The differential device 5 includes the ring gear 51, a differential case 50, a differential mechanism portion 50c disposed inside the differential case 50, and an output shaft 55. The ring gear 51 rotates about a fourth axis J4. The differential device 5 thus rotates about the fourth axis J4. The fourth axis J4 is an imaginary axis extending parallel to the first axis J1. The ring gear 51 is meshed with the third gear 43. The ring gear 51 is fixed to the outer peripheral surface of the differential case 50.

[0032] The differential case 50 includes a housing portion 50b that houses the differential mechanism portion 50c therein, and a pair of hollow shafts 50a that project toward one side and the other in the axial direction relative to the housing portion 50b. The hollow shafts 50a are tubular and extend in the axial direction with the fourth axis J4 as the center. The hollow shafts 50a rotate about the fourth axis J4 together with the ring gear 51. One of the two hollow shafts 50a is rotatably supported on the gear cover 82 via the fourth bearing 6D. The other of the two hollow shafts 50a is rotatably supported on a housing body 81 via the fifth bearing 6E. The fourth bearing 6D and the fifth bearing 6E thus support the ring gear 51.

[0033] A pair of output shafts 55 are connected to the differential device 5. The two output shafts 55 protrude from the differential case 50 of the differential device 5 to one side and the other in the axial direction. The two output shafts 55 are arranged inwardly of the hollow shafts 50a. The two output shafts 55 are rotatably supported on the inner peripheral surface of the hollow shafts 50a. The output shafts 55 rotate about the fourth axis J4. (Housing)

[0034] The housing 80 includes a housing base 81, a gear cover 82, and a motor cover 83. The housing base 81, the gear cover 82, and the motor cover 83 are each separate elements. The gear cover 82 is arranged on one side (+Y side) of the housing base 81 in the axial direction. The motor cover 83 is arranged on the other side (-Y side) of the housing base 81 in the axial direction.

[0035] The housing 80 includes a first receiving portion 80A that receives the rotating electric machine 2, a second receiving portion (receiving portion) 80B that receives the driving force transmitting portion 3, and the partition wall portion 88. The second receiving portion 80B is located on the axially one side (+Y side) of the first receiving portion 80A. The partition wall portion 88 is located between the first receiving portion 80A and the second receiving portion 80B.

[0036] The first receiving portion 80A is formed by a peripheral wall portion 81d of the housing main body 81 and the motor cover 83, which covers an opening of the peripheral wall portion 81d on the other side in the axial direction (-Y side). The rotating electric machine 2 is arranged in the space surrounded by the housing main body 81 and the motor cover 83.

[0037] The second receiving portion 80B is formed by a concave portion 82d opening on the axial direction side (+Y side) of the housing main body 81, and the gear cover 82 covering the opening of the concave portion. The driving force transmitting portion 3 is arranged in the space surrounded by the housing main body 81 and the gear cover 82. Details of the gear cover 82 will be described later.

[0038] The partition wall portion 88 separates an interior space of the first receiving portion 80A and an interior space of the second receiving portion 80B. A first through-hole 88a and a second through-hole 88b are provided in the partition wall portion 88. The first through-hole 88a and the second through-hole 88b communicate the interior space of the first receiving portion 80A and the interior space of the second receiving portion 80B. The motor shaft 21 passes through the first through-hole 88a.

[0039] A fluid O is housed inside the housing 80. The fluid O circulates in flow channels 90A, 90B described below. In the present embodiment, the fluid O is oil, which is used not only for cooling the electric rotary machine 2 but also for lubricating the drive force transmission section 3. To fulfill both the function of lubricating oil and cooling oil, an oil equivalent to automatic transmission fluid (ATF) having a comparatively low viscosity is preferably used as the fluid O.

[0040] A first storage portion P and a second storage portion 89 are provided inside the second receiving portion 80B. The first storage portion P stores the fluid O at the bottom of the drive force transmitting portion 3. The second storage portion 89, on the other hand, stores the fluid O at the top of the drive force transmitting portion 3.

[0041] The first storage portion P is provided in a lower region in the interior of the second accommodation portion 80B. The fluid O accumulated in the first storage portion P is scooped up by the operation of the drive force transmission portion 3 and distributed in the second accommodation portion 80B. The fluid O distributed in the second accommodation portion 80B is supplied to the individual gears of the drive force transmission portion 3 in the second accommodation portion 80B, so that the fluid O flows over the tooth surfaces of the gears. The fluid O supplied to the drive force transmission portion 3 and used for lubrication drips down and is collected in the first storage portion P of the second accommodation portion 80B.

[0042] The second storage portion 89 is provided inside the second accommodation portion 80B. The second accommodation portion 80B is a so-called catch tank. The second storage portion 89 is open at the top. The second accommodation portion 80B stores a portion of the fluid O absorbed due to the operation of the drive force transmitting portion 3. In the present embodiment, the second storage portion 89 is formed, for example, by abutting a rib projecting from a surface of the partition wall portion facing one side in the axial direction (+Y side) to the other axial direction and a rib extending from a surface of the transmission cover 82 facing the other axial direction (-Y side). The second storage portion 89 may also be a separate member from the housing 80.

[0043] The fluid O of the first storage portion P is conveyed into the interior of the first accommodation portion 80A through the flow channels 90A, 90B described below. The fluid O conveyed into the interior of the first accommodation portion 80A drips from the rotary electric machine 2 and collects on the upper surface of a bottom portion 81a of the first accommodation portion 80A. The bottom portion 81a of the first accommodation portion 80A is located higher than a bottom portion of the second accommodation portion 80B. The fluid O that accumulates on the bottom portion 81a of the first accommodation portion 80A passes through the second through-hole 88b to the second accommodation portion 80B and returns to the first storage portion P.

[0044] The flow channels 90A, 90B are flow channels that transport the fluid O in the first storage section P to the first receiving section 80A. The flow channels 90A have a first flow channel 91, a second flow channel 92, a third flow channel 93, and a fourth flow channel 94. The flow channels 90B have a scooping path 99, a fifth flow channel 95, and a sixth flow channel 96.

[0045] The first flow channel 91 is a flow channel that connects the first storage section P and the pump 8. The pump 8 sucks the fluid O in the first storage section P and pressurizes it downstream. The second flow channel 92 is a flow channel that connects the pump 8 and the cooler 9. The fluid O is cooled by the cooler 9. The third flow channel 93 is a flow channel that connects the cooler 9 and the interior of the first receiving section 80A. The third flow channel 93 is a flow channel that extends through the interior of the partition wall section 88.

[0046] The fourth flow channel 94 is a flow channel that distributes the fluid O inside the first accommodation portion 80A. The fourth flow channel 94 is provided inside a pipe 94P. The pipe 94P is arranged in the interior of the first accommodation portion 80A above the stator 30. The pipe 94P extends axially through the interior of the first accommodation portion 80A. A plurality of discharge holes are provided on the pipe 94P. The fluid O passing through the fourth flow channel 94 is discharged from the discharge holes. A portion of the fluid O discharged from the discharge holes is supplied to the rotating electric machine 2 and cools the rotating electric machine 2.

[0047] The scooping path 99 is a path that scoops up the fluid O accumulating in the first storage portion P due to the rotation of the ring gear 51 and directs it to the second storage portion 89. The fluid O scooped up by the ring gear 51 is distributed in the interior of the second receiving portion 80B, and a part of it is supplied to the second storage portion 89.

[0048] The fifth flow channel 95 is a flow channel that guides the fluid O from the second storage portion 89 into the interior of the first shaft 44. The fifth flow channel 95 of the present embodiment is a hole formed in the gear cover 82 using a drill or the like.

[0049] The sixth flow channel 96 is a flow channel provided inside the first shaft 44 and the motor shaft 21. The fluid O in the sixth flow channel 96 is subjected to centrifugal force due to the rotation of the rotor 20. A through hole is provided in the motor shaft 21, connecting the hollow portion and the outer peripheral surface. The fluid O of the sixth flow channel 96 sprays outward in the radial direction due to the centrifugal force of the rotor 20 and is supplied to the stator 30. (gearbox cover)

[0050] The gear cover 82 covers the opening of the concave portion 82d of the housing body 81 facing the one side in the axial direction (+Y side). The gear cover 82 is located on the one side in the axial direction (+Y side) of the drive force transmission section 3. The gear cover 82 supports the plurality of shafts 44, 45, 50a of the drive force transmission section 3.

[0051] The gear cover 82 includes a reduction device cover portion 75 that covers the reduction device 4 from one side in the axial direction (+Y), and a differential device cover portion 74 that covers the differential device 5 from one side in the axial direction (+Y). The reduction device cover portion 75 supports the first shaft 44 and the second shaft 45 of the reduction device 4 via the first bearing 6A and the second bearing 6B. Thus, the first axis J1 and the second axis J2 pass through the reduction device cover portion 75. The differential device cover portion 74, in turn, supports the hollow shaft 50a of the differential device 5 via the fourth bearing 6D. A through hole 74h through which the output shaft 55 passes is provided in the differential device cover portion 74. The through hole 74h is circular with the fourth axis J4 as its center.

[0052] Fig. 2 is a front view of the gear cover 82 of the present embodiment. Fig. 3 is a perspective view of the gear cover 82 of the present embodiment.

[0053] As in Fig. 2 and Fig. As shown in Figure 3, dome portions 71, 72, 73 are provided on the reduction gear cover portion 75. That is, the gear cover 82 includes the dome portions 71, 72, 73. The dome portions 71, 72, 73 each project toward the axially extending side (+Y side) with a dome axis extending in the axial direction as the center. In this document, the "dome axis" is an imaginary axis that forms the center of a dome shape. The dome axis passes through the apex portion of each dome portion.

[0054] The plurality of coupling sections 71, 72, 73 include a first coupling section 71, a second coupling section 72, and a third coupling section 73. The transmission cover 82 thus has the first coupling section 71, the second coupling section 72, and the third coupling section 73 as coupling sections. The first coupling section 71 has the first axis J1 as the coupling axis. The second coupling section 72 has the second axis J2 as the coupling axis. The third coupling section 73 has the third axis J3 as the coupling axis. The third axis J3 is an imaginary axis that extends parallel to the first axis J1 and the second axis J2.

[0055] Fig. 4 is a schematic sectional view of the first dome section 71.

[0056] In Fig. 4 is just like in Fig. 5 and Fig. 6 ribs and noses are not shown.

[0057] The outer surface 71f of the first dome section 71 is a dome shape whose center is the first axis (dome axis) J1. Fig. 4, a single cutting surface is shown out of countless cutting surfaces passing through the first axis J1, but the outer side surface 71f of the first dome section 71 also has the same outer shape on the other cutting surfaces passing through the first axis J1.

[0058] The first dome portion 71 has an apex portion 71a and a slope portion 71b. The apex portion 71a and the slope portion 71b are the portions on the outer side surface 71f of the first dome portion 71. The outer side surface 71f of the first dome portion 71 denotes a surface of the first dome portion 71 facing one side in the axial direction (+Y side). An inner side surface 71g of the first dome portion 71, described below, denotes a surface of the first dome portion 71 facing the other side in the axial direction (-Y side).

[0059] The apex portion 71a is an end portion of the first dome portion 71 on the one side in the axial direction (+Y side). The first axis (dome axis) J1 passes through the apex portion 71a. In the present embodiment, the apex portion 71a is a point where the first axis J1 and the apex of the outer side surface 71f of the first dome portion 71 intersect.

[0060] The inclined portion 71b widens from the apex portion 71a toward the radially outer side of the first axis (dome axis) J1. The inclined portion 71b increasingly inclines from the apex portion 71a toward the radially outer side of the first axis J1 toward the other side in the axial direction.

[0061] Let a specific tangent L be assumed at any point Q of the inclined section 71b among the tangents of the inclined section 71b, passing through the first axis J1. Also, let an imaginary plane F be assumed to be orthogonal to the first axis J1. The plane F is a plane parallel to the XZ plane. An angle formed by the specific tangent L and the plane F is considered the angle of inclination θ of the inclined section 71b at point Q.

[0062] In the present embodiment, when the point Q on the inclined portion 71b is shifted to the other side in the axial direction, the inclination angle θ of the inclined portion 71b gradually increases. That is, in the inclined portion 71b, the inclination angle θ with respect to the plane F orthogonal to the first axis J1 becomes larger from the apex portion 71a toward the radially outer side.

[0063] Since the first dome portion 71 of the present embodiment is a dome shape with the first axis J1 as its center, the inclination angle θ of the inclined portion 71b remains constant when the point Q on the inclined portion 71b is displaced in a circumferential direction around the first axis J1. However, the inclination angle θ is not necessarily constant when the point Q is displaced in the circumferential direction.

[0064] According to the present embodiment, by providing the first dome portion 71 on the gear cover 82, the area moment of inertia around the first axis J1 of the gear cover 82 can be increased compared to a flat shape. Thus, the strength of the gear cover 82 can be increased, and diaphragm vibration of the gear cover 82 due to vibration of the drive force transmission portion 3 can be suppressed. As a result, noise during the drive of the drive device 1 is suppressed, and the working efficiency of the drive device 1 can also be increased due to the reduction of energy loss associated with vibration.

[0065] In the present embodiment, the first bearing 6A, which supports the first shaft 44, is arranged inside the first coupling portion 71. The first axis J1, which is the center of the first shaft 44, is the coupling axis of the first coupling portion 71. The first coupling portion 71 achieves high strength against the vibration transmitted from the first bearing 6A to the gear cover 82 and can suppress vibration of the first bearing 6A.

[0066] In the present embodiment, a first bearing holder 71h is provided on the inner side surface 71g of the first coupling portion 71, which holds the first bearing 6A. The first bearing holder 71h is tubular with the first axis J1 as its center. The first bearing holder 71h holds the outer ring of the first bearing 6A on its inner side surface. According to the present embodiment, the first coupling portion 71 can suppress vibrations of the first bearing 6A and increase the transmission efficiency of the drive force transmission portion 3.

[0067] Fig. 5 is a schematic sectional view of the second dome section 72.

[0068] The second dome portion 72 has substantially the same configuration as the first dome portion 71. The outer side surface 72f of the second dome portion 72 is a dome shape whose center is the second axis (dome axis) J2.

[0069] The second dome portion 72 has an apex portion 72a and a slope portion 72b. The apex portion 72a and the slope portion 72b are the portions on the outer side surface 72f of the second dome portion 72. The outer side surface 72f of the second dome portion 72 refers to a surface of the second dome portion 72 facing one side in the axial direction (+Y side). An inner side surface 72g of the second dome portion 72, described below, refers to a surface of the second dome portion 72 facing the other side in the axial direction (-Y side).

[0070] The apex portion 72a is an end portion of the first dome portion 72 on the one side in the axial direction (+Y side). The second axis (dome axis) J2 passes through the apex portion 72a. In the present embodiment, the apex portion 72a is a point where the second axis J2 and the apex of the outer side surface 72f of the second dome portion 72 intersect.

[0071] The inclined portion 72b widens from the apex portion 72a toward the radially outer side of the second axis (dome axis) J2. The inclined portion 72b slopes progressively from the apex portion 72a toward the radially outer side of the second axis J2 toward the other axial side. In the inclined portion 72b, the angle of inclination with respect to the plane orthogonal to the second axis J2 increases from the apex portion 72a toward the radially outer side.

[0072] The inclination angle of the inclined portion 72b of the second dome portion 72 has the same configuration as the configuration described for the inclination angle θ of the inclined portion 72b of the first dome portion 71. That is, an angle formed by the tangent at any point on the inclined portion 72b and the second axis J2 is the inclination angle of the inclined portion 72b at that point, and by shifting this point to the radially outer side, the inclination angle of the inclined portion 72b at that point gradually becomes larger.

[0073] According to the present embodiment, by providing the second coupling portion 72 on the transmission cover 82 in addition to the first coupling portion 71, the area moment of inertia about the second axis J2 of the transmission cover 82 can be increased. In this way, the strength of the transmission cover 82 can be increased. As shown in Fig. As shown in Figure 2, the second coupling portion 72 in the present embodiment is connected to the first coupling portion 71. The second coupling portion 72 and the first coupling portion 71 thus increase the mutual strength and thus contribute to a further increase in the strength of the transmission cover 82.

[0074] As in Fig. As shown in Fig. 5, in the present embodiment, the second bearing 6B, which supports the second shaft 45, is disposed inside the second coupling portion 72. The second axis J2, which is the center of the second shaft 45, is the coupling axis of the second coupling portion 72. Therefore, the second coupling portion 72 achieves high strength against the vibration transmitted from the second bearing 6B to the transmission cover 82 and can suppress vibration of the second bearing 6B.

[0075] In the present embodiment, a second bearing holder 72h is provided on the inner side surface 72g of the second coupling portion 72, which holds the second bearing 6B. The second bearing holder 72h is tubular with the second axis J2 as its center. The second bearing holder 72h holds the outer ring of the second bearing 6B on its inner side surface. According to the present embodiment, the second coupling portion 72 can suppress vibrations of the second bearing 6B and increase the transmission efficiency of the drive force transmission portion 3.

[0076] Fig. 6 is a schematic sectional view of the third dome section 73.

[0077] The outer side surface 73f of the third dome portion 73 is a dome shape centered on the third axis (dome axis) J3. The third dome portion 73 is connected to a truncated cone portion 79 at the end portion on the other side in the axial direction (-Y side).

[0078] The truncated cone section 79 is truncated conically with the third axis J3 as its center. Consequently, the outer surface 79f of the truncated cone section 79 is inclined at a constant angle from the radially outer side to the other axial side (-Y side). The outer surface 79f of the truncated cone section 79 is seamlessly connected to an outer surface 73f of the third dome section 73 at a boundary surface BF orthogonal to the central axis J.

[0079] The third dome portion 73 has an apex portion 73a and a slope portion 73b. The apex portion 73a and the slope portion 73b are the portions on the outer side surface 73f of the third dome portion 73. The outer side surface 73f of the third dome portion 73 denotes a surface of the third dome portion 73 facing one side in the axial direction (+Y side). An inner side surface 73g of the third dome portion 73, described below, denotes a surface of the third dome portion 73 facing the other side in the axial direction (-Y side).

[0080] The apex portion 73a is an end portion of the third dome portion 73 on the one side in the axial direction (+Y side). The third axis (dome axis) J3 passes through the apex portion 73a. In the present embodiment, the apex portion 73a is a point where the third axis J3 and the apex of the outer side surface 73f of the third dome portion 73 intersect.

[0081] The inclined portion 73b widens from the apex portion 73a toward the radially outer side of the third axis (dome axis) J3. The inclined portion 73b increasingly inclines from the apex portion 73a toward the radially outer side of the third axis J3 toward the other side in the axial direction. In the inclined portion 73b, the inclination angle with respect to the plane orthogonal to the third axis J3 increases from the apex portion 73a toward the radially outer side.

[0082] The inclination angle of the inclined portion 73b of the third dome portion 73 has the same configuration as the configuration described for the inclination angle θ of the inclined portion 73b of the first dome portion 71. That is, an angle formed by the tangent at any point on the inclined portion 73b and the third axis J3 is the inclination angle of the inclined portion 73b at that point, and by shifting this point to the radially outer side, the inclination angle of the inclined portion 73b at that point gradually becomes larger.

[0083] According to the present embodiment, by providing the third coupling portion 73 on the transmission cover 82 in addition to the first coupling portion 71 and the second coupling portion 72, the geometric moment of inertia about the third axis J3 of the transmission cover 82 can be increased. In this way, the strength of the transmission cover 82 can be further increased.

[0084] As in Fig. As shown in Figure 2, the third coupling portion 73 in the present embodiment is connected to the first coupling portion 71 and the second coupling portion 72. The third coupling portion 73 and the second coupling portion 72 thus increase the mutual strength and thus contribute to a further increase in the strength of the transmission cover 82. This effect can be achieved even more strongly if the third coupling portion 73 is connected to at least one of the first coupling portion 71 and the second coupling portion 72.

[0085] As in Fig. 6, a part of the second storage portion 89 is disposed inside the third dome portion 73. In the present embodiment, a part of the second storage portion 89 is connected to the inner side surface 73g of the third dome portion 73. By providing the third dome portion 73 on the gear cover 82, in the area superimposed on the third dome portion 73 in the axial direction, the internal space of the housing 80 expands toward the axially one side (+Y side). According to the present embodiment, by disposing a part of the second storage portion 89 inside the third dome portion 73, the internal space of the housing 80 expanded due to the third dome portion 73 is effectively utilized, whereby the storage amount of the second storage portion 89 can be increased.By increasing the storage amount of the second storage portion 89, a larger proportion of the fluid O accumulated in the first storage portion P can be collected in the second storage portion 89. This allows the level of the fluid O accumulated in the first storage portion P to be kept low, so that the stirring resistance of the fluid O acting on the drive force transmission portion 3 can be reduced.

[0086] In the present embodiment, the case where three coupling portions 71, 72, 73 are provided on the transmission cover 82 is described. However, as long as the transmission cover 82 has at least one of the first coupling portion 71, the second coupling portion 72, and the third coupling portion 73, the effect of suppressing diaphragm vibrations due to vibrations of the drive force transmission portion 3 can be achieved.

[0087] In the present embodiment, the outer side surfaces 71f, 72f, 73f of the dome portions 71, 72, 73 are curved as a whole. Therefore, the outer side surfaces 71f, 72f, 73f of the dome portions 71, 72, 73 are also curved at the apex portions 71a, 72a, 72b, and the dome portions 71, 72, 73 are points through which the dome axis (first axis J1, second axis J2, or third axis J3) passes. However, the apex portion 71a may also be circular when viewed from the axial direction and be a flat surface orthogonal to the first axis J1. In this case, the inclined portion 71b widens from the outer edge of the circular apex portion to the radially outer side.

[0088] As in Fig.As shown in Figure 3, on an outer side surface 82a of the gear cover 82, a plurality of ribs 61, 62, 63, 64, 65, a plurality of projections 68, and a plurality of filler holes 69 are provided on the axially one side (+Y side) of the outer side surface 82a. The ribs 61, 62, 63, 64, 65 and the projections 68 protrude toward the axially one side (+Y side) of the outer side surface 82a.

[0089] The refill holes 69 are through holes extending axially through the transmission cover 82. The refill holes 69 of the present embodiment are provided in the differential device cover portion 74. Caps 69C are attached to the refill holes 69. The refill holes 69 are provided for draining the fluid O from the second receiving portion 80B or refilling the fluid O.

[0090] The plurality of protrusions 68 are provided on the reduction device cover portion 75. The plurality of protrusions 68 are each provided on one of the outer side surfaces of the first coupling portion 71, the second coupling portion 72, and the third coupling portion 73. In the gear cover 82 of the present embodiment, seven protrusions 68 are provided. A screw hole 68a extending in the axial direction is provided on one end surface of the protrusions 68. The protrusions 68 are used, for example, to support the gear cover 82 in the assembly process of the drive device 1. The protrusions 68 can also be used to fix the drive device 1 to a vehicle.

[0091] The plurality of ribs 61, 62, 63, 64, 65 include a first rib 61, second rib 62, third rib 63, fourth rib 64, and fifth rib 65. Thus, on the gear cover 82, the first rib 61, the second rib 62, the third rib 63, the fourth rib 64, and the fifth rib 65 are provided as the above-mentioned ribs.

[0092] The first rib 61 and the second rib 62 are arranged spanningly between the differential device cover portion 74 and the reduction device cover portion 75. The first rib 61 and the second rib 62 reinforce the differential device cover portion 74 and the reduction device cover portion 75.

[0093] The first rib 61 has a circular arc portion 61a, a first straight portion 61b connected to one end portion of the circular arc portion 61a, and a second straight portion 61c connected to the other end portion of the circular arc portion 61a.

[0094] The circular arc portion 61a is arranged on the differential device cover portion 74. The circular arc portion 61a extends in a circular arc shape with the fourth axis J4 as the center when viewed from the axial direction. By providing the circular arc portion 61a of the first rib 61 on the differential device cover portion 74, the strength of the transmission cover 82 around the fourth axis J4 can be increased, and vibration of the transmission cover 82 during the drive of the differential device 5 can be suppressed.

[0095] The circular arc section 61a extends, with the fourth axis J4 as its center, over a range of substantially 180° in the circumferential direction. One end section of the circular arc section 61a lies above the fourth axis J4. The other end section of the circular arc section 61a, however, lies below the fourth axis J4.

[0096] The first straight portion 61b and the second straight portion 61c are disposed between the differential device cover portion 74 and the reduction device cover portion 75. The first straight portion 61b and the second straight portion 61c extend rectilinearly when viewed from the axial direction. The first straight portion 61b and the second straight portion 61c extend substantially in parallel.

[0097] The first straight portion 61b is provided on the outer side surface 74f of the differential device cover portion 74 and the outer side surface 73f of the third dome portion 73. By being provided on the outer side surface 73f of the third dome portion 73, the first straight portion 61b reinforces the third dome portion 73. The third dome portion 73 protrudes toward the axial one side (+Y side) with respect to the differential device cover portion 74. Therefore, the first straight portion 61b extends from the differential device cover portion 74 toward the third dome portion 73 with increasing curvature toward the axial one side (+Y side).

[0098] One end of the first straight section 61b is connected to the circular arc section 61a. The other end of the first straight section 61b is connected to a first projection 68A, which is one of the plurality of projections 68. Thus, the first rib 61 is connected to one of the plurality of projections 68 at the first straight section 61b. The strength of the first rib 61 is increased by the first projection 68A.

[0099] The second straight portion 61c is provided on the outer side surface 74f of the differential device cover portion 74 and the outer side surface 72f of the second dome portion 72. By being provided on the outer side surface 72f of the second dome portion 72, the second straight portion 61c reinforces the second dome portion 72. The second dome portion 72 protrudes toward the axial one side (+Y side) with respect to the differential device cover portion 74. Therefore, the second straight portion 61c extends from the differential device cover portion 74 toward the second dome portion 72 with increasing curvature toward the axial one side (+Y side).

[0100] One end of the second straight section 61c is connected to the circular arc section 61a. The other end of the second straight section 61c is connected to a second projection 68B, which is one of the plurality of projections 68. Thus, the first rib 61 is connected to one of the plurality of projections 68 at the second straight section 61c. The strength of the first rib 61 is increased by the second projection 68B.

[0101] In this document, a "circular arc shape" need not be a circular arc in the strict sense, as long as it extends curved along the circumferential direction of the fourth axis J4. Likewise, in this document, a "rectilinear shape" need not be a straight line in the strict sense, as long as it extends in one direction.

[0102] According to the present embodiment, the first rib 61 on the first straight portion 61b connects the third coupling portion 73 and the differential device cover portion 74. Also, the first rib 61 on the second straight portion 61c connects the second coupling portion 72 and the differential device cover portion 74. Since the second coupling portion 72 and the third coupling portion 73 protrude further than the differential device cover portion 74 toward the axial direction (+Y side), the first rib 61 extends toward the axial direction (+Y side) with respect to the differential device cover portion 74. Therefore, the first rib 61 reinforces the differential device cover portion 74 from the axial direction (+Y side). The force of the differential device 5 acts on the differential device cover portion 74 from the axial direction (+Y side).According to the present embodiment, the differential device cover portion 74 can absorb the force from the differential device 5 through the first rib 61, so that the gear cover 82 can be effectively reinforced around the fourth axis J4. Thus, diaphragm vibrations of the gear cover 82 during the drive of the differential device 5 can be suppressed.

[0103] The second rib 62 is located further radially inward than the first rib 61 in the radial direction centered on the fourth axis J4. The second rib 62 includes a circular arc portion 62a, a third straight portion 62b connected to one end portion of the circular arc portion 62a, and a fourth straight portion 62c connected to the other end portion of the circular arc portion 62a. Thus, the second rib 62 includes the circular arc portion 62a and the two straight portions 62b, 62c extending in a straight line from the two end portions of the circular arc portion 62a.

[0104] The circular arc portion 62a is arranged on the differential device cover portion 74. The circular arc portion 62a extends in a circular arc shape with the fourth axis J4 as the center when viewed from the axial direction. By providing the circular arc portion 62a of the second rib 62 on the differential device cover portion 74, the strength of the transmission cover 82 around the fourth axis J4 can be increased, and vibration of the transmission cover 82 during the drive of the differential device 5 can be suppressed.

[0105] The circular arc portion 62a of the second rib 62 is located further radially inward in the radial direction centered on the fourth axis J4 than the circular arc portion 61a of the first rib 61. When viewed from the axial direction, a radius of curvature of the circular arc portion 62a of the second rib 62 is smaller than a radius of curvature of the circular arc portion 61a of the first rib 61. According to the present embodiment, by arranging the first rib 61 and the second rib 62 concentrically adjacent to each other around the fourth axis J4 as the center, the strength of the gear cover 82 around the fourth axis J4 can be further effectively increased.

[0106] The circular arc section 62a extends circumferentially over a range of substantially 180° with the fourth axis J4 as its center. One end section of the circular arc section 62a lies above the fourth axis J4. The other end section of the circular arc section 62a, however, lies below the fourth axis J4.

[0107] The third straight portion 62b and the fourth straight portion 62c are disposed between the differential device cover portion 74 and the reduction device cover portion 75. The third straight portion 62b and the fourth straight portion 62c extend straightly when viewed from the axial direction. In the up-down direction, the two straight portions of the second rib 62 (third straight portion 62b and fourth straight portion 62c) are disposed between the two straight portions of the first rib 61 (first straight portion 61b and second straight portion 61c). The two straight portions of the second rib (third straight portion 62b and fourth straight portion 62c) extend so as to approach each other as the distance from the fourth axis J4 increases.In this way, the third straight portion 62b and the fourth straight portion 62c between the first straight portion 61b and the second straight portion 61c can effectively increase the strength of the gear cover 82.

[0108] The third straight portion 62b is provided on the outer side surface 74f of the differential device cover portion 74 and the outer side surface 73f of the third dome portion 73. By being provided on the outer side surface 73f of the third dome portion 73, the third straight portion 62b reinforces the third dome portion 73. The third dome portion 73 protrudes toward the axial one side (+Y side) with respect to the differential device cover portion 74. Therefore, the third straight portion 62b extends from the differential device cover portion 74 toward the third dome portion 73 with increasing curvature toward the axial one side (+Y side).

[0109] One end of the third straight section 62b is connected to the circular arc section 62a. The other end of the third straight section 62b is connected to a third projection 68C, which is one of the plurality of projections 68. Thus, the second rib 62 is connected to one of the plurality of projections 68 at the third straight section 62b. The strength of the second rib 62 is increased by the third projection 68C.

[0110] The fourth straight portion 62c is provided on the outer side surface 74f of the differential device cover portion 74 and the outer side surface 72f of the second dome portion 72. By being provided on the outer side surface 72f of the second dome portion 72, the fourth straight portion 62c reinforces the second dome portion 72. The second dome portion 72 protrudes toward the axial one side (+Y side) with respect to the differential device cover portion 74. Therefore, the fourth straight portion 62c extends from the differential device cover portion 74 toward the second dome portion 72 with increasing curvature toward the axial one side (+Y side).

[0111] One end of the fourth straight section 62c is connected to the circular arc section 62a. The other end of the fourth straight section 62c is connected to a fourth projection 68D, which is one of the plurality of projections 68. Thus, the second rib 62 is connected to one of the plurality of projections 68 at the fourth straight section 62c. The strength of the second rib 62 is increased by the fourth projection 68D.

[0112] According to the present embodiment, the second rib 62, like the first rib 61, connects the third coupling portion 73 and the differential device cover portion 74 at the third straight portion 62b and the second coupling portion 72 and the differential device cover portion 74 at the fourth straight portion 62c. The second rib 62 extends on the outer side surfaces 72f, 73f of the second coupling portion 72 and the third coupling portion 73 that protrude toward the axially one side (+Y side). Therefore, the second rib 62 can reinforce the differential device cover portion 74 from the axially one side (+Y side) and suppress diaphragm vibrations of the transmission cover 82 during the drive of the differential device 5.

[0113] In the present embodiment, it has been described that the first rib 61 and the second rib 62 respectively connect the differential device cover portion 74 and the second dome portion 72 and the third dome portion 73. However, the dome portion that the first rib 61 and the second rib 62 connect to the differential device cover portion 74 may also be a dome portion that protrudes to the axial direction (+Y side) of the differential device cover portion 74. Thus, the dome portion that the first rib 61 and the second rib 62 connect to the differential device cover portion 74 may be any of the first dome portion 71, the second dome portion 72, and the third dome portion 73.

[0114] The plurality of third ribs 63 are provided on the reduction gear cover portion 75. The third ribs 63 connect the projections 68 to each other. The third ribs 63 each extend linearly when viewed from the axial direction. According to the present embodiment, the third ribs 63 reinforce the projections 68 by connecting the projections 68 to each other.

[0115] The plurality of third ribs 63 are provided on one or two outer side surfaces of the first dome portion 71, the second dome portion 72, and the third dome portion 73, respectively. Therefore, the third ribs 63 reinforce the first dome portion 71, the second dome portion 72, and the third dome portion 73. Some of the plurality of third ribs 63 intersect each other. The intersecting third ribs 63 reinforce each other.

[0116] The fourth ribs 64 are provided on the reduction device cover portion 75. In the present embodiment, three fourth ribs 64 are provided on the gear cover 82. One of the three fourth ribs 64 connects the first straight portion 61b of the first rib 61 and the third projection 68C. The remaining two of the three fourth ribs 64 connect the second straight portion 61c of the first rib 61 and the fourth projection 68D. Thus, the fourth ribs 64 reinforce the first rib 61 and effectively increase the strength of the reduction device cover portion 75.

[0117] The fifth ribs 65 are provided on the differential device cover portion 74. The plurality of fifth ribs 65 extend radially in the radial direction with the fourth axis J4 as the center. The plurality of fifth ribs 65 connect the circular arc portion 61a of the first rib 61 and the circular arc portion 62a of the second rib 62. Thus, the fifth ribs 65 reinforce the first rib 61 and the second rib 62, effectively increasing the strength of the differential device cover portion 74.

[0118] While various embodiments of the present invention have been described above, the individual configurations, their combinations, etc., in the embodiments are merely examples. Configurations may be added, omitted, or replaced, or other changes may be made without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiment.

[0119] As long as the drive device is one that can move an object using an electric rotary machine as the driving force source, there are no particular restrictions. The direction of extension of the central axis is not particularly restricted. The central axis can also extend in the vertical direction.

[0120] In the above embodiment, it was described that the drive device does not include an inverter unit, but this is not limited to this. The drive device may include an inverter unit. In other words, the drive device may have an integral structure with an inverter unit.

[0121] The purpose of the drive device is not particularly limited. The drive device does not need to be installed in a vehicle. As long as they are not mutually exclusive, the structural elements described in this specification can be combined as desired.

[0122] The present technique may also take the following forms. (1) A drive device comprising: an electric rotary machine having a rotor rotating around a central axis, a driving force transmission portion coupled to the electric rotary machine on one side in the axial direction of the electric rotary machine, and a housing accommodating the electric rotary machine and the driving force transmission portion, wherein the housing has a gear cover located on one side in the axial direction of the driving force transmission portion and supporting a shaft of the driving force transmission portion, wherein the gear cover has a coupling portion having a coupling axis extending in the axial direction as a center and projecting to the one side in the axial direction, wherein the coupling portion has an apex portion through which the coupling axis passes,and a slant section widening from the apex section to a radially outer side, wherein the slant section increasingly inclines from the apex section toward the radially outer side toward the other side in the axial direction, wherein an angle of inclination with respect to a plane orthogonal to the coupling axis becomes increasingly larger from the apex section toward the radially outer side. (2) The drive device of (1), wherein the drive force transmitting portion includes a first gear rotating about a first axis, wherein the gear cover includes, as the coupling portion, a first coupling portion whose coupling axis is the first axis. (3) The drive device of (2), wherein the drive force transmitting portion includes a first shaft rotating about the first axis together with the first gear, and a first bearing supporting the first shaft, the first bearing being disposed inside the first coupling portion. (4) The drive device of (2) or (3), wherein the drive force transmitting portion includes a second gear meshed with the first gear and rotating about a second axis extending parallel to the first axis, wherein the gear cover includes, as the coupling portion, a second coupling portion whose coupling axis is the second axis. (5) The drive device of (4), wherein the drive force transmitting portion includes a second shaft rotating about the second axis together with the second gear, and a second bearing supporting the second shaft, the second bearing being disposed inside the second coupling portion. (6) The drive device of (4) or (5), wherein the gear cover has, as the coupling portion, a third coupling portion whose coupling axis is a third axis extending parallel to the first axis, the third coupling portion communicating with at least one of the first coupling portion or the second coupling portion. (7) The drive device of (6), comprising an accommodating portion accommodating the driving force transmitting portion, wherein inside the accommodating portion there are provided a first storage portion in which a fluid below the driving force transmitting portion is stored, and a second storage portion in which the fluid above the driving force transmitting portion is stored, wherein a part of the second storage portion is arranged inside the third dome portion. (8) The drive device of any one of (1) to (7), wherein the drive force transmitting portion includes a differential device rotating about a fourth axis extending parallel to the center axis, wherein the transmission cover includes a differential device covering portion covering the differential device from the axial direction one side. (9) The drive device of (8), wherein the coupling portion protrudes toward the axially one side with respect to the differential device cover portion, wherein a rib connecting the coupling portion and the differential device cover portion to each other is provided on a surface of the transmission cover facing the axially one side. (10) The drive device of (9), wherein the rib has a circular arc section when viewed from the axial direction, which extends in a circular arc with the fourth axis as the center. (11) The drive device of (10), wherein a first rib and a second rib are provided on the gear cover as the rib, the circular arc portion of the second rib being located radially further inward in a radial direction with the fourth axis as the center than the circular arc portion of the circular arc portion of the first rib. (12) The drive device of (11), wherein the second rib has a pair of straight portions extending straightly from the two end portions of the circular arc portion, the two straight portions approaching each other as the distance from the fourth axis increases. (13) The drive device of any one of (9) to (12), wherein on a surface of the gear cover facing the axially one side, a plurality of projections are provided that project toward the axially one side, the rib being in communication with one of the plurality of projections. (14) The drive device of (13), wherein a third rib connecting the lugs to each other is provided on a surface of the gear cover facing the axially one side. EXPLANATION OF REFERENCE SYMBOLS 1 drive device 2 electric rotary machines 3 Drive force transmission section 5 Differential device 6A first camp 6B second camp 20 rotors 41 gear 41 first gear 42 second gear 44 Wave 44 first wave 45 second wave 61 first rib (rib) 61a, 62a circular arc section 62 second rib (rib) 62b, 62c straight section 63 third rib 68 approach 71 first dome section (dome section) 71a, 72a, 73a apex section 71b, 72b, 73b Inclined section 72 second dome section (dome section) 73 third dome section (dome section) 74 Differential device cover section 80 housings 80B second receiving section (receiving section) 82 Gearbox cover 89 second storage section F Area J Central axis J1 first axle (coupled axle) J2 second axle (coupled axle) J3 third axle (coupled axle) J4 fourth axis O Fluid P first memory section θ angle of inclination QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2022-105974

[0002] JP 2010-246180 A

[0004]

Claims

[1] Drive device comprising: an electric rotary machine having a rotor rotating about a central axis, a driving force transmission section coupled to the electric rotary machine on one side of the electric rotary machine in the axial direction, and a housing that houses the electric rotary machine and the drive force transmission section, wherein the housing has a gear cover which is located on one side of the drive force transmission section in the axial direction and supports a shaft of the drive force transmission section, wherein the gear cover has a dome portion having as its center a dome axis extending in the axial direction and projecting to one side in the axial direction, wherein the dome section has an apex section through which the dome axis runs, and an oblique section widening from the apex section to a radially outer side, wherein the inclined section inclines from the apex section to the radially outer side increasingly towards the other side in the axial direction, wherein an angle of inclination with respect to a plane orthogonal to the coupling axis becomes increasingly larger from the apex portion toward the radially outer side. [2] The drive device according to claim 1, wherein the drive force transmitting portion includes a first gear rotating about a first axis, wherein the gear cover includes, as the coupling portion, a first coupling portion whose coupling axis is the first axis. [3] The drive device according to claim 2, wherein the drive force transmitting portion includes a first shaft rotating about the first axis together with the first gear, and a first bearing supporting the first shaft, the first bearing being disposed inside the first coupling portion. [4] The drive device according to claim 2, wherein the drive force transmitting portion includes a second gear meshed with the first gear and rotating about a second axis extending parallel to the first axis, wherein the gear cover includes, as the coupling portion, a second coupling portion whose coupling axis is the second axis. [5] The drive device according to claim 4, wherein the drive force transmitting portion includes a second shaft rotating about the second axis together with the second gear, and a second bearing supporting the second shaft, the second bearing being disposed inside the second coupling portion. [6] The drive device according to claim 4, wherein the transmission cover has, as the coupling portion, a third coupling portion whose coupling axis is a third axis extending parallel to the first axis, the third coupling portion being connected to at least one of the first coupling portion or the second coupling portion. [7] A drive device according to claim 6, comprising a receiving portion which receives the drive force transmission portion, wherein inside the receiving portion there is a first storage portion in which a fluid is stored below the drive force transmission portion, and a second storage section is provided in which the fluid is stored above the drive force transmission section, wherein a part of the second storage section is arranged inside the third dome section. [8] The drive device according to claim 1, wherein the drive force transmitting portion includes a differential device rotating about a fourth axis extending parallel to the center axis, wherein the transmission cover includes a differential device covering portion covering the differential device from the one side in the axial direction. [9] The drive device according to claim 8, wherein the coupling portion projects toward the one side in the axial direction with respect to the differential device cover portion, and a rib connecting the coupling portion and the differential device cover portion to each other is provided on a surface of the transmission cover facing the one side in the axial direction. [10] The drive device according to claim 9, wherein the rib has a circular arc portion when viewed from the axial direction, which extends in a circular arc with the fourth axis as the center. [11] The drive device according to claim 10, wherein a first rib and a second rib are provided on the gear cover as the rib, the circular arc portion of the second rib being located radially further inward in a radial direction with the fourth axis as the center than the circular arc portion of the circular arc portion of the first rib. [12] The drive device according to claim 11, wherein the second rib has a pair of straight portions extending straightly from the two end portions of the circular arc portion, the two straight portions approaching each other as the distance from the fourth axis increases. [13] The drive device according to claim 9, wherein on a surface of the gear cover facing the axially one side, a plurality of projections are provided which project toward the axially one side, the rib being in communication with one of the plurality of projections. [14] A drive device according to claim 13, wherein a third rib connecting the lugs to each other is provided on a surface of the gear cover facing the axially one side.

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