Vehicle drive transmission device

Abstract

To provide a vehicle drive transmission device which is compact and stabilizes a position in a thrust direction along a drive shaft center.SOLUTION: A planetary deceleration mechanism G has a sun gear 21, a ring gear 22, a pinion gear 23, a support shaft 24 which supports the pinion gear 23, and a carrier section 26a which rotates together with the support shaft 24. A differential gear mechanism D has a differential case 26 which integrally rotates with the carrier section 26a. A radial bearing 6 is arranged between a first protrusion section T1 which protrudes from a bulkhead 11 in a case 10 in a direction toward the carrier section 26a and a second protrusion section T2 which protrudes from the carrier section 26a toward the bulkhead 11. A main thrust bearing 7 is arranged between a first regulation section R1 on an outer periphery of an intermediary transmission shaft 3 with the sun gear 21 formed thereon and a second regulation section R2 positioned closer to the differential gear mechanism D than the first regulation section R1 of the carrier section 26a.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a vehicle drive transmission device. [Background technology]

[0002] Patent Document 1 discloses a vehicle drive transmission device (referred to as a power transmission device in the document) that reduces the driving force of a motor using a first planetary reduction gear and a second planetary reduction gear, transmits the reduced driving force to a differential device, and then transmits the reduced driving force from the differential device to a pair of drive shafts.

[0003] The vehicle drive transmission device described in Patent Document 1 has a transmission configuration in which the driving force from the carrier, which has been reduced in speed by a first planetary reduction mechanism, is transmitted to the sun gear of a second planetary reduction mechanism, and the second planetary reduction mechanism reduces the speed using a plata-neli gear (referred to as a stepped pinion gear in the document) before transmitting it to a differential case of the differential device.

[0004] Furthermore, in Patent Document 1, a shaft (called a pinion shaft in the document) that supports the planetary gear is supported on the differential case, so that part of the differential case functions as a carrier for the second planetary reduction mechanism. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 161977 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, one end of the differential case is supported on the case by a bearing, and the other end of the differential case is supported on an intermediate cover disposed adjacent to the case by a bearing. The two bearings supporting the differential case are of the radial type.

[0007] The sun gear that meshes with the plata-neri gear of the second planetary reduction mechanism shown in Patent Document 1 has teeth formed on the outer periphery of a cylindrical member that is fitted onto the drive shaft so as to be rotatable relative to the drive shaft. Patent Document 1 also uses a thrust type needle bearing that abuts against the end of the cylindrical member to determine the axial position of the cylindrical member on which the sun gear is formed.

[0008] However, if the differential case is supported by two radial bearings, it may be difficult to determine the position of the differential case in the thrust direction.

[0009] For these reasons, there is a demand for a compact vehicle drive transmission device whose position in the thrust direction along the drive shaft is stabilized. [Means for solving the problem]

[0010] A characteristic configuration of a vehicle drive transmission device according to the present invention is a vehicle drive transmission device that transmits drive force between a drive force source and a pair of wheels, and includes a planetary reduction mechanism that reduces the speed of rotation transmitted from the drive force source and transmits it to the pair of wheels, a differential gear mechanism that distributes the drive force transmitted from the planetary reduction mechanism to the pair of wheels, and a case that accommodates the planetary reduction mechanism and the differential gear mechanism, wherein the planetary reduction mechanism has a sun gear that rotates about a drive shaft by the drive force of the drive force source, a ring gear provided in the case, a pinion gear that meshes with the sun gear and the ring gear and revolves about the drive shaft, a support shaft that supports the pinion gear, and a carrier portion that revolves together with the support shaft, and the differential gear mechanism includes a differential case that rotates integrally with the carrier portion about the drive shaft by the drive force from the planetary reduction mechanism, and a differential case that is accommodated inside the differential case and rotates around the drive shaft in conjunction with the rotation of the differential case. and a gear portion that transmits driving force to a drive shaft coaxial with the drive shaft, the case has a partition wall therein oriented perpendicular to the drive shaft core, the partition wall includes a first protruding portion protruding toward the carrier portion from an annular region centered on the drive shaft core, the carrier portion includes a second protruding portion protruding toward the partition from an annular region centered on the drive shaft core and having a different diameter from the first protruding portion, a radial bearing is provided between the first protruding portion and the second protruding portion, the sun gear is formed on an intermediate transmission shaft that rotates around the drive shaft by transmitting driving force from the driving force source, the intermediate transmission shaft includes a first regulating portion on its outer periphery extending in a direction perpendicular to the drive shaft core, and the carrier portion includes a second regulating portion that is on the side of the differential gear mechanism closer to the first regulating portion and overlaps with the first regulating portion when viewed in a direction along the drive shaft core, and a main thrust bearing is provided between the first regulating portion and the second regulating portion.

[0011] According to this characteristic configuration, a radial bearing is provided between the first protruding portion formed on the partition wall and the second protruding portion formed on the carrier portion, so that the carrier portion of the differential case can be rotatably supported on the case. Also, a main thrust bearing is provided between the first restricting portion that is perpendicular to the drive shaft core with respect to the intermediate transmission shaft on which the sun gear is formed, and the second restricting portion of the carrier portion that is closer to the differential gear mechanism than the first restricting portion, so that the thrust load of the sun gear can be restricted by the main thrust bearing. Also, since the radial bearing is supported by the second protruding portion of the carrier portion, and the main thrust bearing is supported by the second restricting portion of the carrier portion, a compact shaft length can be achieved. Thus, a compact vehicle drive transmission device is configured, with a stable position in the thrust direction along the drive shaft core. [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view of a vehicle drive transmission device. [Diagram 2] 1 is a skeleton plan view of a vehicle drive transmission device; [Diagram 3] 4 is an enlarged cross-sectional view of an interlocking portion between the planetary reduction mechanism and the differential gear mechanism. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of a vehicle drive transmission device according to the present invention will be described with reference to the drawings. In this embodiment, as an example of a vehicle drive transmission device, a configuration in which the drive force of an electric motor (drive force source) is reduced and transmitted to a differential gear mechanism, and then transmitted from the differential gear mechanism to a pair of wheels will be described. However, the present invention is not limited to the following embodiment, and various modifications are possible within the scope of the gist of the present invention.

[0014] [Basic configuration] As shown in FIGS. 1 to 3, a vehicle drive transmission device A is configured by housing an electric motor M as a drive force source, a planetary reduction mechanism G, and a differential gear mechanism D in a drive case 10 (an example of a case).

[0015] This vehicle drive transmission device A is installed in vehicles such as fuel cell vehicles (FCVs) and electric vehicles (EVs), which travel by reducing the driving force of an electric motor M using a reduction unit and transmitting it to a pair of left and right wheels W through a differential gear mechanism D.

[0016] The electric motor M functions as a motor generator that outputs a driving torque using electric power supplied from an external source and generates electricity using the torque transmitted from the wheels W.

[0017] 1 and 3, a partition wall 11 is formed in the center of the internal space of the drive case 10. The drive case 10 is detachably provided with a lid-like body 12 that closes the motor-side space 10a in which the electric motor M is housed, and a case-like lid body 13 that closes the reduction-side space 10b in which the planetary reduction mechanism G and the differential gear mechanism D are housed.

[0018] The drive case 10 accommodates an intermediate drive shaft 1 (an example of a drive shaft) in an area penetrating the partition wall 11, centered on a drive shaft core X. One end of the intermediate drive shaft 1 is supported by the differential gear mechanism D in a state of being fitted into a side gear 27a of the differential gear mechanism D, and the other end is rotatably supported by the cover-shaped body 12 via a first bearing B1.

[0019] A cylindrical drive shaft 2 is disposed in a region that is coaxial with the drive shaft core X and covers the outer periphery of the intermediate drive shaft 1. One end of the cylindrical drive shaft 2 is supported by a second bearing B2 against the partition wall 11, and the other end is supported by a third bearing B3 against a boss portion 12a that is integrally formed with the lid-like body 12.

[0020] The first bearing B1, the second bearing B2, and the third bearing B3 are each configured as a radial ball type.

[0021] 1, the electric motor M has a stator 15 fixed to a drive case 10, and a rotor 16 that rotates about a drive shaft core X by a magnetic field acting from the stator 15. The rotor 16 is fitted and fixed to the outer periphery of a cylindrical drive shaft 2.

[0022] The stator 15 has coils 15a wound around each of a plurality of teeth made of laminated electromagnetic steel sheets. The rotor 16 has laminated electromagnetic steel sheets and a plurality of gaps 16a provided in the electromagnetic steel sheets.

[0023] The planetary reduction mechanism G has a sun gear 21, a ring gear 22, a pinion gear 23 meshing with the sun gear 21 and the ring gear 22, and a support shaft 24 supporting the pinion gear 23 for free rotation.

[0024] The sun gear 21 is integrally formed on the outer periphery of a cylindrical intermediate transmission shaft 3 which is spline-fitted to the end of the cylindrical drive shaft 2. The ring gear 22 is non-rotatably provided on the inner surface of the drive case 10. The pinion gear 23 has a large diameter gear portion 23a which meshes with the sun gear 21, a small diameter gear portion 23b which meshes with the ring gear 22, and a cylindrical shaft portion 23c which is connected to these. The pinion gear 23 is called a stepped pinion gear or a two-stage gear.

[0025] 3, the spindle 24 is supported by a differential case 26 of the differential gear mechanism D. In the planetary reduction mechanism G, a portion of the differential case 26 that supports the spindle 24 is called a carrier portion 26a, and this carrier portion 26a functions as a carrier.

[0026] The differential gear mechanism D has a differential case 26 that is rotatable about the drive shaft center X, and a gear portion 27 that is housed in the differential case 26 and transmits driving force to the intermediate drive shaft 1 as the differential case 26 rotates. The gear portion 27 has a pair of side gears 27a that are arranged coaxially with the drive shaft center X, a pinion shaft 27b that is oriented perpendicular to the drive shaft center X, and a pair of pinion gears 27c that mesh with each of the pair of side gears 27a.

[0027] As described above, in the differential gear mechanism D, the shaft 24 of the pinion gear 23 of the planetary reduction mechanism G is supported by the differential case 26. This allows a part of the differential case 26 that supports the shaft 24 to function as a carrier for the planetary reduction mechanism G.

[0028] The carrier portion 26a has a cylindrical outer surface centered on the drive shaft core X, and a plurality of open spaces 26b are formed radially penetrating the carrier portion 26a. The support shaft 24, which serves as an axis parallel to the drive shaft core X, is disposed inside the open spaces 26b, and the pinion gear 23 is supported by the support shaft 24.

[0029] As shown in Figures 1 and 3, of the pair of side gears 27a of the differential gear mechanism D, the side gear 27a is positioned closer to the case-like cover body 13 with respect to the pinion shaft 27b. A wheel drive shaft 30 that transmits driving force to one of the wheels W is fitted into the fitting hole of the side gear 27a.

[0030] Further, a wheel drive shaft 30 for transmitting driving force to the other wheel W is fitted into a fitting hole at the end of the intermediate drive shaft 1 facing the lid-like body 12 .

[0031] With this configuration, when the electric motor M is driven, in the planetary reduction mechanism G, the intermediate transmission shaft 3 rotates due to the driving force from the cylindrical drive shaft 2, and the sun gear 21 rotates around the drive shaft core X. Due to the rotation of the sun gear 21, the pinion gear 23, whose large diameter gear portion 23a meshes with the sun gear 21, rotates around the support shaft 24, and at the same time, since the small diameter gear portion 23b of the sun gear 21 meshes with the ring gear 22, it begins to revolve around the drive shaft core X.

[0032] As a result, the differential gear mechanism D rotates about the drive shaft core X due to the driving force that is reduced in speed by the planetary reduction mechanism G and transmitted from the support shaft 24 to the differential case 26.

[0033] As the differential case 26 rotates about the drive shaft center X, the differential gear mechanism D transmits driving force from one side gear 27a to the wheel drive shaft 30, thereby driving and rotating one of the wheels W. The differential gear mechanism D also transmits driving force from the other side gear 27a to the intermediate drive shaft 1 and the wheel drive shaft 30, thereby driving and rotating the other wheel W.

[0034] [Bearing structure] 3, the differential case 26 is supported by a first radial bearing 5 and a second radial bearing 6 to be rotatable about the drive shaft core X relative to the drive case 10. The first radial bearing 5 and the second radial bearing 6 are configured as radial ball bearings.

[0035] Furthermore, the differential case 26 is positioned in the direction along the drive shaft center X by the main thrust bearing 7 and the sub thrust bearing 8. The main thrust bearing 7 and the sub thrust bearing 8 are configured as a thrust needle type.

[0036] The first radial bearing 5 is provided in such a manner that its inner race contacts the outer periphery of the differential case 26 on the opposite side of the planetary reduction mechanism G with respect to the differential gear mechanism D, and its outer race contacts the inner periphery of the hole-like portion of the case-shaped cover body 13.

[0037] The partition 11 has a first protrusion T1 that protrudes toward the carrier portion 26a from an annular region centered on the drive shaft core X. The carrier portion 26a has a second protrusion T2 that protrudes toward the partition 11 from an annular region centered on the drive shaft core X and having a smaller diameter than the first protrusion T1.

[0038] Due to this configuration, the second radial bearing 6 is provided in a form in which an inner race is in contact with the outer periphery of the second protruding portion T2, and an outer race is in contact with the inner periphery of the first protruding portion T1.

[0039] 3, the intermediate transmission shaft 3 has a spline-type fitting portion formed on the outer periphery of the end portion of the cylindrical drive shaft 2 on the side of the reduction-side space 10b. The intermediate transmission shaft 3 is cylindrical with a large diameter portion and a small diameter portion, and the inner periphery of the large diameter portion is fitted into the fitting portion of the cylindrical drive shaft 2 by a technique such as spline so as to be able to transmit torque. The intermediate transmission shaft 3 has a sun gear 21 formed on the outer periphery of the small diameter portion.

[0040] A disk-shaped first restricting portion R1 extending in a direction perpendicular to the drive shaft core X is formed on the outer periphery of the large diameter portion of the intermediate transmission shaft 3.

[0041] The carrier portion 26a has a second regulating portion R2 that overlaps the first regulating portion R1 when viewed in a direction along the drive shaft core X, on the side of the differential gear mechanism D from the first regulating portion R1. The first regulating portion R1 and the second regulating portion R2 are formed as smooth surfaces (annular surfaces centered on the drive shaft core X) that are perpendicular to the drive shaft core X and in a positional relationship facing each other, and the main thrust bearing 7 is disposed between them.

[0042] The partition wall 11 has a third regulating portion R3 that overlaps with the first regulating portion R1 in the direction along the drive shaft core X. This third regulating portion R3 is formed as a smooth surface (annular surface centered on the drive shaft core X) that is perpendicular to the drive shaft core X and in a positional relationship facing the first regulating portion R1, and the secondary thrust bearing 8 is disposed so as to be sandwiched between the first regulating portion R1 and the third regulating portion R3.

[0043] In this vehicle drive transmission device A, the large diameter gear portion 23a of the pinion gear 23 and the sun gear 21 are configured as helical gears. By configuring them as helical gears in this manner, when the vehicle is driven forward by the rotation of the wheels W, a thrust force is applied to displace the intermediate transmission shaft 3 in a direction away from the differential gear mechanism D along the drive shaft center X, and this thrust force is received by the sub thrust shaft 8. In addition, when the vehicle is driven forward by the rotation of the wheels W, a thrust force is applied to displace the intermediate transmission shaft 3 in a direction toward the differential gear mechanism D along the drive shaft center X, and this thrust force may be received by the main thrust shaft 7.

[0044] 3, the rotation direction of the sun gear 21 is the same as the rotation direction of the carrier portion 26a of the differential case 26. Therefore, the relative speed difference between the first regulating portion R1 and the second regulating portion R2 is smaller than the relative speed difference between the first regulating portion R1 and the third regulating portion R3 of the partition wall 11 (stationary system).

[0045] By providing the main thrust bearing 7 at a location where the relative speed difference is small in this manner, the decrease in the life of the main thrust bearing 7 is suppressed, and the life can be extended.

[0046] In contrast, when the vehicle is driven in reverse, a thrust force is applied that displaces the intermediate transmission shaft 3 along the drive shaft axis X toward the partition wall 11, and this thrust force is received by the secondary thrust bearing 8. Although the secondary thrust bearing 8 receives the thrust force at a portion where the relative speed difference between the intermediate transmission shaft 3 and the third regulating portion R3 and the first regulating portion R1 of the partition wall 11 is large, the frequency of reverse driving is lower than the frequency of forward driving, thereby suppressing the disadvantage of a shortened lifespan.

[0047] In this way, the vehicle drive transmission device A uses the main thrust bearing 7 and the sub thrust bearing 8 to determine the position of the first regulating portion R1 of the intermediate transmission shaft 3, thereby suppressing displacement of the planetary reduction mechanism G and the differential gear mechanism D in the direction along the drive shaft core X.

[0048] [Lubrication structure] As shown in Figures 1 and 3, in a vehicle drive transmission device A, lubricating oil is supplied from a lubricating oil supply passage E formed in a motor side space 10a to a lubricating central oil passage 1a formed coaxially with a drive axis X of the intermediate drive shaft 1.

[0049] The intermediate drive shaft 1 has a flow path that flows lubricating oil from a central lubricating oil passage 1a in a direction along the drive shaft center X to supply it to the differential gear mechanism D, and a lubricating oil branch passage 1b that flows lubricating oil in a direction branching radially from the central lubricating oil passage 1a.

[0050] The lubricating oil from the lubrication branch oil passage 1b is supplied to the inner periphery of the intermediate transmission shaft 3. A plurality of through oil passages penetrating in the radial direction are formed in this intermediate transmission shaft 3, and a gap is formed between the end of the intermediate transmission shaft 3 and the second bearing B2. As a result, the lubricating oil supplied to the inner periphery of the intermediate transmission shaft 3 is supplied to the main thrust bearing 7 and the sub thrust bearing 8 from the through oil passages or the gaps at the end by centrifugal force accompanying the rotation of the intermediate transmission shaft 3.

[0051] The lubricating oil supplied to the main thrust bearing 7 and the sub thrust bearing 8 is sent outward by centrifugal force and is supplied to the second radial bearing 6. Furthermore, the lubricating oil sent out from the outer periphery of the second radial bearing 6 is supplied from the lubricating oil flow path F to the receiver 31 of the carrier portion 26a.

[0052] The receiver 31 has a supply hole 31a that receives the lubricating oil sent from the lubricating oil flow path F and supplies the lubricating oil from the carrier portion 26a to the support shaft 24. The support shaft 24 has a lubricating oil path 24a that supplies the lubricating oil supplied from the supply hole 31a to its outer periphery.

[0053] With this configuration, when the vehicle is running, the vehicle drive transmission device A supplies lubricating oil supplied to the central lubrication oil passage 1a to the main thrust bearing 7 and the sub thrust bearing 8. Next, the lubricating oil is supplied to the second radial bearing 6, and further supplied from the lubricating oil passage F through the receiver 31 to the needle bearing between the outer periphery of the support shaft 24 and the inner periphery of the pinion gear 23.

[0054] [Effects of the embodiment] In the vehicle drive transmission device A, the first radial bearing 5 and the second radial bearing 6 support the differential case 26 on the drive case 10 so as to be rotatable about the drive shaft center X. This supports the differential case 26 over a long span in the direction along the drive shaft center X, enabling stable rotation.

[0055] In particular, the second radial bearing 6 is provided in a form in which it is inserted between a first protruding portion T1 that protrudes in the direction of the carrier portion 26a from an annular region of the partition wall 11 centered on the drive shaft center X, and a second protruding portion T2 that protrudes in the direction of the partition wall 11 from an annular region of the carrier portion 26a centered on the drive shaft center X. This makes it possible to easily install the second radial bearing 6.

[0056] Furthermore, the vehicle drive transmission device A uses a main thrust bearing 7 and a sub thrust bearing 8 that receive thrust force in the direction along the drive shaft center X. This makes it possible to position the planetary reduction mechanism G and the differential gear mechanism D without increasing the size in the direction along the drive shaft center X.

[0057] The main thrust bearing 7 is disposed between a first restricting portion R1 on the outer periphery of the intermediate transmission shaft 3 and a second restricting portion R2 of the carrier portion 26a. Furthermore, the sub thrust bearing 8 is disposed between a third restricting portion R3 of the partition wall 11 and the first restricting portion R1, thereby realizing positioning in the direction along the drive shaft core X.

[0058] The large diameter gear portion 23a of the pinion gear 23 and the sun gear 21 are configured as helical gears, and the intermediate transmission shaft 3 is displaced together with the sun gear 21 in a direction along the drive shaft center X. In this way, the thrust force acting in one direction is utilized, and the movement of the intermediate transmission shaft 3 on which this thrust force acts is regulated by the main thrust bearing 7 and the sub thrust bearing 8, thereby realizing the positioning of the planetary reduction mechanism G and the differential gear mechanism D.

[0059] The outer diameter of the region of the intermediate transmission shaft 3 where the sun gear 21 is formed is smaller than the outer diameter of the region that fits onto the cylindrical drive shaft 2. Therefore, compared to an intermediate transmission shaft 3 configured to have a linear cylindrical shape, for example, the number of teeth of the sun gear 21 is reduced and the number of teeth of the large diameter gear portion 23a is increased, making it possible to achieve a large reduction ratio for deceleration.

[0060] In this vehicle drive transmission device A, lubricating oil from the central lubricating oil passage 1a of the intermediate drive shaft 1 flows in the order of the main thrust bearing 7 and the second radial bearing 6, and the lubricating oil sent out from the second radial bearing 6 is supplied to the receiver 31 through the lubricating oil passage F. This allows the pinion gear 23 to rotate smoothly, enabling good power transmission.

[0061] [Another embodiment] The present invention may be configured as follows other than the above-described embodiment (common numbers and symbols as in the embodiment are used to designate components having the same functions as in the embodiment).

[0062] In the embodiment (a), the first protruding portion T1 and the second protruding portion T2 shown in FIG. 3 are disposed in a positional relationship opposite to that in the radial direction, and a second radial bearing 6 is provided therebetween.

[0063] That is, in this alternative embodiment (a), a first protruding portion T1 is formed on the partition wall 11, a second protruding portion T2 having a diameter larger than that of the first protruding portion T1 is formed on the carrier portion 26a, and the second radial bearing 6 is provided between them. In this alternative embodiment (a), it is also possible to configure the lubricating oil pumped out from the outer periphery of the second radial bearing 6 to be supplied to the receiver 31 of the carrier portion 26a in the same manner as in the embodiment.

[0064] In this alternative embodiment (a), as in the embodiment, a main thrust bearing 7 can be arranged between the first regulating portion R1 and the second regulating portion R2, and a secondary thrust bearing 8 can be arranged between the first regulating portion R1 and the third regulating portion R3.

[0065] (b) The pinion gear 23 of the planetary reduction mechanism G is not limited to a two-stage gear, but may be a single-stage gear in which the same tooth surface meshes with the sun gear 21 and the ring gear 22.

[0066] (c) A further planetary reduction mechanism G is added upstream in the power transmission direction from the planetary reduction mechanism G shown in the embodiment. A plurality of planetary reduction mechanisms G may be added in this manner.

[0067] (d) A thrust washer is used instead of the needle-type thrust bearing. In this alternative embodiment (d), a plurality of thrust washers can be stacked.

[0068] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, provided no contradiction arises. Furthermore, the embodiments disclosed in this specification are merely examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope that does not deviate from the purpose of the present invention.

[0069] In the above-described embodiment, the following configurations are envisaged. (1) A vehicle drive transmission device A that transmits drive force between a drive force source (electric motor M) and a pair of wheels W, comprising: a planetary reduction mechanism G that reduces the rotation transmitted from the drive force source (electric motor M) and transmits it to the pair of wheels W; a differential gear mechanism D that distributes the drive force transmitted from the planetary reduction mechanism G to the pair of wheels W; and a case (drive case 10) that accommodates the planetary reduction mechanism G and the differential gear mechanism D. The planetary reduction mechanism G includes a sun gear 21 that rotates around a drive shaft core X by the drive force of the drive force source (electric motor M); The differential gear mechanism D includes a ring gear 22 provided in the case 10, a pinion gear 23 meshing with the sun gear 21 and the ring gear 22 and revolving around the drive shaft center X, a support shaft 24 supporting the pinion gear 23, and a carrier portion 26a revolving together with the support shaft 24. The differential gear mechanism D includes a differential case 26 which rotates integrally with the carrier portion 26a around the drive shaft center X by a driving force from the planetary reduction mechanism G, and a drive shaft 1 housed inside the differential case 26 and which applies a driving force to the drive shaft 1 coaxial with the drive shaft center X in conjunction with the rotation of the differential case 26. and a gear portion 27 for transmitting the torque, and the case (drive case 10) has a partition wall 11 therein, which is oriented perpendicular to the drive shaft center X, and the partition wall 11 includes a first protruding portion T1 protruding in the direction of the carrier portion 26a from an annular region centered on the drive shaft center X, and the carrier portion 26a includes a second protruding portion T2 protruding in the direction of the partition wall 11 from an annular region centered on the drive shaft center X and having a different diameter from the first protruding portion T1, and a radial bearing (second radial bearing 6) is provided between the first protruding portion T1 and the second protruding portion T2. the sun gear 21 is formed on an intermediate transmission shaft 3 which rotates around the drive shaft center X as a result of the transmission of driving force from the drive force source (electric motor M), the intermediate transmission shaft 3 includes a first regulating portion R1 extending in a direction perpendicular to the drive shaft center X on its outer periphery, the carrier portion 26a includes a second regulating portion R2 which is located closer to the differential gear mechanism D than the first regulating portion R1 and overlaps with the first regulating portion R1 as viewed in a direction along the drive shaft center X, and a main thrust bearing 7 is provided between the first regulating portion R1 and the second regulating portion R2.

[0070] According to this characteristic configuration, a radial bearing (second radial bearing 6) is provided between the first protruding portion T1 formed on the partition wall 11 and the second protruding portion T2 formed on the carrier portion 26a, so that the carrier portion 26a of the differential case 26 can be rotatably supported on the case (drive case 10). In addition, a main thrust bearing 7 is provided between the first restricting portion R1 perpendicular to the drive shaft center X with respect to the intermediate transmission shaft 3 on which the sun gear 21 is formed, and the second restricting portion R2 of the carrier portion 26a on the side of the differential gear mechanism D from the first restricting portion R1, so that the thrust load of the sun gear 21 can be restricted by the main thrust bearing 7. In addition, the radial bearing (second radial bearing 6) is supported by the second protruding portion T2 of the carrier portion 26a, and the main thrust bearing 7 is supported by the second restricting portion R2 of the carrier portion 26a, so that a compact shaft length can be realized. Thus, a compact vehicle drive transmission device A is configured, in which the position in the thrust direction along the drive shaft center X is stabilized.

[0071] (2) In the vehicle drive transmission device A of (1), it is preferable that the partition 11 includes a third regulating portion R3 that overlaps with the first regulating portion R1 in a direction along the drive shaft core X, and a secondary thrust bearing 8 is provided between the first regulating portion R1 and the third regulating portion R3.

[0072] According to this, by providing the sub-thrust bearing 8, the displacement of the differential case 26 along the drive shaft axis X in the direction approaching the partition wall 11 can be restricted by the sub-thrust bearing 8.

[0073] (3) In the vehicle drive transmission device A of (1), a lubricating oil flow path F is formed to send the lubricating oil supplied to the main thrust bearing 7 to the radial bearing (second radial bearing 6) and to send it outward from the outer periphery of the radial bearing (second radial bearing 6), and it is preferable that the carrier portion 26a has a receiver 31 that receives the lubricating oil sent outward from the outer periphery of the radial bearing (second radial bearing 6) and supplies it between the support shaft 24 and the pinion gear 23.

[0074] According to this, after being supplied to the radial bearing (second radial bearing 6), the lubricating oil discharged from the outer periphery of the radial bearing (second radial bearing 6) is supplied to the receiver 31 from the lubricating oil flow path F, thereby supplying lubricating oil between the outer periphery of the support shaft 24 and the pinion gear 23, enabling the pinion gear 23 to rotate smoothly.

[0075] (4) In the vehicle drive transmission device A of (1), it is preferable that the intermediate transmission shaft 3 is fitted in a torque transmissible manner onto the outer periphery of a cylindrical drive shaft 2 to which drive force from the drive force source (electric motor M) is transmitted.

[0076] As a result, the configuration in which the sun gear 21 is formed on the intermediate transmission shaft 3 and fitted to the cylindrical drive shaft 2 is easier to manufacture than, for example, a configuration in which the sun gear 21 is integrally formed on the outer periphery of the cylindrical drive shaft 2, because the length in the direction along the drive shaft core X can be shortened, and the position of the sun gear 21 can be easily adjusted by moving it relative to the intermediate transmission shaft 3 in the direction along the drive shaft core. [Industrial Applicability]

[0077] The present invention can be used in a vehicle drive transmission device. [Explanation of symbols]

[0078] 1: intermediate drive shaft (drive shaft), 3: intermediate transmission shaft, 6: second radial bearing (radial bearing), 7: main thrust bearing, 8: secondary thrust bearing, 10: drive case (case), 11: partition wall, 21: sun gear, 22: ring gear, 23: pinion gear, 24: support shaft, 26: differential case, 26a: carrier portion, 27: gear portion, 31: receiver, A: vehicle drive transmission device, D: differential gear mechanism, F: lubricating oil flow path, G: planetary reduction mechanism, M: electric motor (driving force source), R1: first regulating portion, R2: second regulating portion, R3: third regulating portion, T1: first protruding portion, T2: second protruding portion, W: wheel, X: drive shaft core

Claims

1. A vehicle drive transmission device that transmits drive force between a drive force source and a pair of wheels, a planetary reduction mechanism that reduces the speed of rotation transmitted from the driving force source and transmits the rotation to the pair of wheels; a differential gear mechanism that distributes the driving force transmitted from the planetary reduction mechanism to the pair of wheels; a case that accommodates the planetary reduction mechanism and the differential gear mechanism, the planetary reduction mechanism includes a sun gear that rotates about a drive shaft by the driving force of the driving force source, a ring gear provided in the case, a pinion gear that meshes with the sun gear and the ring gear and revolves about the drive shaft, a support shaft that supports the pinion gear, and a carrier portion that revolves together with the support shaft, the differential gear mechanism includes a differential case that rotates integrally with the carrier unit around the drive shaft core by a driving force from the planetary reduction mechanism, and a gear unit that is accommodated inside the differential case and transmits a driving force to a drive shaft coaxial with the drive shaft core in conjunction with the rotation of the differential case, The case has a partition wall therein and is oriented perpendicular to the drive shaft center, the partition wall includes a first protrusion protruding from an annular region centered on the drive shaft toward the carrier portion, the carrier portion includes a second protruding portion protruding toward the partition wall from an annular region having a different diameter from the first protruding portion and centered on the drive shaft center, A radial bearing is provided between the first protruding portion and the second protruding portion, the sun gear is formed on an intermediate transmission shaft that rotates around the drive shaft by transmitting a driving force from the drive force source, and the intermediate transmission shaft includes a first restricting portion on an outer periphery thereof that extends in a direction perpendicular to the drive shaft core, the carrier portion includes a second restricting portion that is located closer to the differential gear mechanism than the first restricting portion and overlaps with the first restricting portion as viewed in a direction along the drive shaft center, A vehicle drive transmission device, comprising: a main thrust bearing provided between the first restricting portion and the second restricting portion.

2. the partition wall includes a third restricting portion overlapping with the first restricting portion in a direction along the drive shaft center, 2. The vehicle drive transmission device according to claim 1, further comprising a sub-thrust bearing provided between the first restricting portion and the third restricting portion.

3. A lubricating oil flow path is formed to send lubricating oil supplied to the main thrust bearing to the radial bearing and to send it outward from the outer periphery of the radial bearing, 2. The vehicle drive transmission device according to claim 1, wherein the carrier portion has a receiver that receives lubricating oil discharged outward from an outer periphery of the radial bearing and supplies the lubricating oil between the support shaft and the pinion gear.

4. 2. The vehicle drive transmission device according to claim 1, wherein the intermediate transmission shaft is fitted in a torque transmitting manner onto an outer periphery of a cylindrical drive shaft to which drive force from the drive force source is transmitted.

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