Transmission device

Abstract

Provided is a transmission device capable of suppressing a reduction in the amount of oil supplied to an oil sump tank. One aspect of the present disclosure is a transmission device provided with a transmission mechanism and a gearbox housing the transmission mechanism. The transmission mechanism has an input gear, a pinion, and a ring gear. The gear box has an oil sump tank, a guide member that feeds oil scraped up by the ring gear to the oil sump tank, and a guide portion that is disposed offset from the guide member in the axial direction of the ring gear and that guides the oil to the guide member. The guide member has an upstream end and a downstream end in a flow direction of the oil. The upstream end is located radially outward of the ring gear. The guide portion extends from a first end connected to an upstream end of the guide member to a second end overlapping the ring gear when viewed from an axial direction of the ring gear.

Description

Technical Field

[0001] The present disclosure relates to a transmission device. Background Art

[0002] In a transmission device having a differential mechanism, there is known a structure in which oil scraped up by a gear for lubricating a bearing is supplied to an oil collecting tank via a guide member (see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-089861 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In the above transmission device, when the rotation speed of the ring gear is low, the amount of oil that does not reach the guide member increases. Therefore, the amount of oil stored in the oil collecting tank decreases, resulting in an increase in the amount of oil soaking the ring gear. Therefore, the stirring resistance of the ring gear increases.

[0008] One aspect of the present disclosure preferably provides a transmission device capable of suppressing a decrease in the amount of oil supplied to an oil collecting tank.

[0009] Solutions to the problem

[0010] One solution of the present disclosure is a transmission device, which includes a transmission mechanism and a gear box for accommodating the transmission mechanism. The transmission mechanism includes: an input gear; a pinion gear having a rotation axis parallel to the rotation axis of the input gear; a ring gear having a rotation axis parallel to the rotation axis of the input gear; a differential case fixed to the ring gear; a differential mechanism disposed inside the differential case; an input gear bearing rotatably supporting the input gear; a pinion gear bearing rotatably supporting the pinion gear; and a differential case bearing rotatably supporting the differential case.

[0011] The secondary gear includes: a first gear meshing with the input gear; and a second gear having an outer diameter smaller than that of the first gear, and being concentrically arranged with the first gear and meshing with the ring gear. The rotation axis of the secondary gear is located above the rotation axis of the input gear and the rotation axis of the ring gear. The gearbox includes: an oil collecting tank; a guide component that sends the oil scraped by the ring gear to the oil collecting tank; and a guide portion that is staggered with the guide component in the axial direction of the ring gear and guides the oil to the guide portion. The guide portion includes an upstream end and a downstream end in the flow direction of the oil. The upstream end is located radially outside the ring gear. The guide portion extends from the first end to the second end, wherein the first end is connected to the upstream end of the guide component, and the second end overlaps with the ring gear when viewed from the axial direction of the ring gear.

[0012] According to the above configuration, the oil scraped up by the ring gear and pushed out in the axial direction of the ring gear is supplied from the guide portion to the guide member. Therefore, it is possible to suppress a reduction in the amount of oil supplied to the oil collecting tank.

[0013] In one embodiment of the present disclosure, the ring gear may be a helical gear with a rotation direction, and when the ring gear rotates in a direction to scrape the oil toward the guide member, the ring gear may transport the oil toward the guide portion. According to the above configuration, the rotation direction of the ring gear causes the oil to be collected in the guide portion, thereby promoting the effect of suppressing the reduction in the oil supply amount of the oil collecting tank.

[0014] In one embodiment of the present disclosure, when viewed from the axial direction of the gear ring, the second end of the guide portion may overlap with a portion of the gear ring before the gear ring reaches its highest point when the gear ring rotates in a direction to scrape the oil toward the guide member, or may overlap with the highest point of the gear ring. According to the above configuration, the effect of suppressing the reduction in the amount of oil supplied to the oil collecting tank can be promoted.

[0015] In one aspect of the present disclosure, the guide portion may be a recessed portion provided on the inner surface of the gear box. According to the above configuration, the shape of the guide portion can be simplified and the cost of forming the guide portion can be reduced.

[0016] In one embodiment of the present disclosure, the differential case may have a window portion connected to the interior. The gear box may have a vertical wall extending downward from the second end of the guide portion toward the window portion. According to the above configuration, oil that cannot reach the guide component via the guide portion can be effectively supplied to the interior of the differential case through the vertical wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic right side view of the transmission device in the embodiment, wherein the transmission device is in a state where the second housing and a part of the bearings are removed.

[0018] Figure 2 It is along Figure 1 Schematic cross-sectional view along line II-II in FIG.

[0019] Figure 3 It is along Figure 1 Schematic cross-sectional view along line III-III in FIG.

[0020] Figure 4 yes Figure 1 A schematic left side view of a transmission device, wherein the transmission device is in a state where the first housing and a portion of the bearings are removed.

[0021] Figure 5 yes Figure 1 A schematic right side view of the first box body.

[0022] Figure 6 yes Figure 4 Schematic left side view of the second box.

[0023] Figure 7 It is along Figure 1 Schematic cross-sectional view along line VII-VII in FIG.

[0024] Figure 8 It is along Figure 1 Schematic cross-sectional view along line VIII-VIII in FIG.

[0025] Fig. 9 It is along Figure 1 Schematic cross-sectional view along line IX-IX in FIG.

[0026] Fig.10 It is along Figure 4 Schematic cross-sectional view of line XX in FIG.

[0027] Fig.11 yes Figure 4 Schematic left side view of the second box.

[0028] Fig.12 yes Figure 1 A schematic right side view of the first box body.

[0029] Description of Reference Numerals

[0030] 1…transmission device; 2…transmission mechanism; 3…gear box; 3A…first housing;

[0031] 3B…Second housing; 21…Input gear; 22…Sub-gear; 23…Ring gear;

[0032] 24 ... differential housing; 31 ... oil collecting tank; 32 ... main guide component; 33 ... guide portion;

[0033] 34 ... vertical wall; 35 ... buffer portion; 36 ... lower guide member; 37 ... reverse guide member;

[0034] 221 ... first gear; 222 ... second gear; 311 ... bottom wall;

[0035] 311A, 311B…communication holes; 312…side wall; 312A…outflow portion; 321…upstream end;

[0036] 322 ... downstream end; 323 ... guide surface; 323A ... groove; 331 ... first end;

[0037] 332 ... second end; 351 ... bottom wall; 352 ... side wall; 352A ... outflow portion;

[0038] 371…upstream end; 372…downstream end; 373…guiding surface. DETAILED DESCRIPTION

[0039] Embodiments to which the present disclosure is applied are described below with reference to the drawings.

[0040] [1. First embodiment]

[0041] [1-1. Structure]

[0042] Figure 1 The transmission device 1 shown is provided in a vehicle and is a transmission device for transmitting power of a driving source of the vehicle to wheels.

[0043] The transmission device 1 includes a transmission mechanism 2, a gear box 3, and a parking lock mechanism 5. The transmission device 1 is installed in a vehicle with the direction parallel to the rotation axis L1 of the input gear 21 of the transmission mechanism 2 being the left-right direction and the direction in which the input gear 21 is arranged relative to the ring gear 23 being the front direction.

[0044] <Transmission Mechanism>

[0045] The transmission mechanism 2 includes an input gear 21 , a pinion gear 22 , a ring gear 23 , a differential case 24 , and a differential mechanism 25 .

[0046] In addition, if Figure 2 As shown, the transmission mechanism 2 includes a first input gear bearing 27A, a second input gear bearing 27B, a first pinion bearing 28A, a second pinion bearing 28B, a first differential case bearing 29A, and a second differential case bearing 29B.

[0047] <Input gear>

[0048] The input gear 21 is an external gear that is drivingly connected to a motor (not shown) and is axially rotated by the driving force of the motor.

[0049] When the car moves forward, the input gear 21 presses Figure 1 When the car moves backward, the input gear 21 rotates counterclockwise. Figure 1 The input gear 21 rotates in the clockwise direction. The rotation axis L1 of the input gear 21 is parallel to the left-right direction.

[0050] The input gear 21 is a right-hand helical gear. Figure 2 As shown, when the vehicle travels in the forward direction, a leftward thrust load F1 is generated on the input gear 21 .

[0051] <Sub-gear>

[0052] The counter gear 22 has a rotation axis L2 that is parallel to the rotation axis L1 of the input gear 21 .

[0053] The rotation axis L2 of the pinion gear 22 is located behind the rotation axis L1 of the input gear 21 and above the rotation axis L1 of the input gear 21 and the rotation axis L3 of the ring gear 23 (see Figure 1 ). The auxiliary gear 22 includes a first gear 221 and a second gear 222 .

[0054] The first gear 221 is an external gear meshing with the input gear 21. The first gear 221 is a left-hand helical gear. When the vehicle travels in the forward direction, a rightward thrust load F2 is generated on the first gear 221.

[0055] Due to the rotation direction of the first gear 221, when the first gear 221 rotates in the rearward direction of the vehicle, the oil scraped by the first gear 221 is sent to the left side.

[0056] That is, the rotation direction of the first gear 221 is such that when the first gear 221 rotates in the rearward direction of the vehicle, the oil is sent to the inner surface of the second casing 3B and the reverse guide member 37 provided on the inner surface.

[0057] The second gear 222 is an external gear meshing with the ring gear 23. The outer diameter of the second gear 222 is smaller than the outer diameter of the first gear 221, and the second gear 222 is arranged concentrically with the first gear 221. The second gear 222 is arranged on the right side of the first gear 221.

[0058] The second gear 222 is a left-handed helical gear. The second gear 222 rotates integrally with the first gear 221. When the automobile travels in the forward direction, a leftward thrust load F3 is generated on the second gear 222. The second gear 222 has a step portion 222A that contacts the first gear 221 in the axial direction. The thrust load F2 of the first gear 221 is borne by the step portion 222A of the second gear 222. Since the thrust load F2 of the first gear 221 and the thrust load F3 of the second gear 222 cancel each other out, the thrust load acting on the first sub-gear bearing 28A and the second sub-gear bearing 28B is reduced.

[0059] <Ring gear>

[0060] The ring gear 23 is an external gear, and has a rotation axis L3 parallel to the rotation axis L1 of the input gear 21. The rotation axis L3 of the ring gear 23 is located behind the rotation axis L2 of the pinion gear 22.

[0061] The ring gear 23 rotates the differential case 24 by the rotational force transmitted from the pinion gear 22 , and scrapes the lubricating oil accumulated at the bottom of the gear case 3 toward the main guide member 32 .

[0062] The ring gear 23 is a right-handed helical gear. When the vehicle travels in the forward direction, a rightward thrust load F4 is generated on the ring gear 23. The thrust load F4 is received by the flange portion 242 of the differential case 24.

[0063] In addition, due to the rotation direction of the ring gear 23, when the ring gear 23 rotates along the forward direction of the vehicle, the oil scraped by the ring gear 23 is sent to the right.

[0064] That is, the rotation direction of the ring gear 23 is such that when the ring gear 23 rotates in the direction of scraping oil toward the main guide component 32 (i.e., the forward direction of the vehicle), the oil is sent to the inner surface of the first housing 3A and the guide portion 33 provided on the inner surface.

[0065] In other words, the rotation direction of the ring gear 23 is such that when the ring gear 23 rotates in a direction to scrape the oil toward the main guide member 32 , the oil is sent to the first differential case bearing 29A side along the axial direction of the ring gear 23 .

[0066] <Differential case>

[0067] The differential case 24 is fixed to the ring gear 23 and rotates together with the ring gear 23 about the rotation axis L3 of the ring gear 23. Figure 3 As shown, the differential case 24 includes a differential mechanism accommodating portion 241 , a flange portion 242 , a first shaft portion 243 , a second shaft portion 244 , and a window portion 245 .

[0068] The differential mechanism accommodating portion 241 accommodates the differential mechanism 25. The flange portion 242 protrudes radially outward from the differential mechanism accommodating portion 241. The ring gear 23 is fixed to the flange portion 242.

[0069] The first shaft portion 243 is a cylindrical portion through which a first output shaft (not shown) connected to the differential mechanism 25 is inserted. The second shaft portion 244 is a cylindrical portion through which a second output shaft (not shown) connected to the differential mechanism 25 is inserted. The window portion 245 is an opening that connects the inside of the differential mechanism accommodating portion 241 and the outside of the differential mechanism accommodating portion 241.

[0070] <Differential Mechanism>

[0071] The differential mechanism 25 is a known mechanism that causes the first output shaft and the second output shaft to rotate at different speeds and distributes and transmits the rotation of the differential case 24 to the first output shaft and the second output shaft. The differential mechanism 25 is disposed inside the differential mechanism accommodating portion 241 .

[0072] The differential mechanism 25 includes two side gears respectively connected to the first output shaft and the second output shaft, and two pinion gears for transmitting the rotation of the differential case 24 to the two side gears.

[0073] The rotation axes of the first output shaft and the second output shaft coincide with the rotation axis of the ring gear 23. The first output shaft and the second output shaft perform differential rotation and rotate according to the rotation direction of the input gear 21 (ie, the rotation direction of the differential case 24).

[0074] <Input gear bearing>

[0075] Figure 2 The first input gear bearing 27A and the second input gear bearing 27B shown are ball bearings that rotatably support the input gear 21 .

[0076] The second input gear bearing 27B is arranged on the opposite side of the first input gear bearing 27A with respect to the teeth of the input gear 21 in the axial direction of the input gear 21. Specifically, the first input gear bearing 27A supports the right end of the shaft of the input gear 21, and the second input gear bearing 27B supports the left end of the shaft of the input gear 21.

[0077] Furthermore, the first input gear bearing 27A is mounted on the first housing 3A. The second input gear bearing 27B is mounted on the second housing 3B.

[0078] <Pinion gear bearing>

[0079] The first pinion bearing 28A and the second pinion bearing 28B are ball bearings that rotatably support the pinion gear 22 .

[0080] The second pinion bearing 28B is arranged on the opposite side of the first pinion bearing 28A relative to the first gear 221 and the second gear 222 in the axial direction of the pinion 22. Specifically, the first pinion bearing 28A supports the right end of the shaft of the pinion 22, and the second pinion bearing 28B supports the left end of the shaft of the pinion 22.

[0081] Furthermore, the first pinion bearing 28A is mounted on the first housing 3A, and the second pinion bearing 28B is mounted on the second housing 3B.

[0082] <Differential case bearing>

[0083] The first differential case bearing 29A and the second differential case bearing 29B are tapered roller bearings that rotatably support the differential case 24 .

[0084] The second differential case bearing 29B is arranged on the opposite side of the first differential case bearing 29A with respect to the ring gear 23 in the axial direction of the ring gear 23. Specifically, the first differential case bearing 29A supports the first shaft portion 243 of the differential case 24, and the second differential case bearing 29B supports the second shaft portion 244 of the differential case 24.

[0085] Furthermore, the first differential case bearing 29A is mounted on the first case 3A, and the second differential case bearing 29B is mounted on the second case 3B.

[0086] <Gearbox>

[0087] The gear box 3 accommodates the transmission mechanism 2. The gear box 3 includes a first case 3A and a second case 3B, and the first case 3A and the second case 3B sandwich the transmission mechanism 2 in the axial direction of the input gear 21 (ie, the left-right direction).

[0088] The first housing 3A and the second housing 3B are connected to each other by a plurality of bolts, thereby forming a storage space for accommodating the transmission mechanism 2, the parking lock mechanism 5, and the oil. Figure 2 In the figure, the portion of the first housing 3A that accommodates a motor (not shown) serving as a driving source is omitted.

[0089] like Figure 1 As shown, in the joint surface between the outer frame of the first housing 3A and the second housing 3B, the widths of the first upper central portion 3C and the first lower central portion 3D (i.e., the thickness in the vertical direction) are greater than the widths of other regions. The first upper central portion 3C is a region overlapping with a portion of the input gear 21, the entire pinion 22, and a portion of the ring gear 23 from above. The first lower central portion 3D is a region overlapping with a portion of the input gear 21, the entire pinion 22, and a portion of the ring gear 23 from below.

[0090] like Figure 4 As shown, similarly to the first upper central portion 3C and the first lower central portion 3D, in the joining surface between the outer frame of the second box body 3B and the first box body 3A, the widths of the second upper central portion 3E and the second lower central portion 3F respectively joined to the first upper central portion 3C and the first lower central portion 3D of the first box body 3A are larger than the widths of other areas.

[0091] By increasing the width of the joint surface in the center of the gear case 3 as described above, it is possible to suppress an increase in the size of the gear case 3 and to suppress oil leakage to the outside of the gear case 3 when the gear case 3 is deformed by a load.

[0092] like Figure 5 and Figure 6 As shown, the gear box 3 has an oil collecting tank 31, a main guide component 32, a guide portion 33, a vertical wall 34, a buffer portion 35, a lower guide component 36, a reverse guide component 37, a reverse vertical wall 38, a first input gear bearing accommodating portion 41A, a second input gear bearing accommodating portion 41B, a first sub-gear bearing accommodating portion 42A, a second sub-gear bearing accommodating portion 42B, a first differential case bearing accommodating portion 43A, a second differential case bearing accommodating portion 43B, a right first sub-gear flow path 45A, a left first sub-gear flow path 45B, a second sub-gear flow path 46, and a differential case flow path 47.

[0093] <Oil collecting tank>

[0094] The oil collecting tank 31 is a part for storing the oil scraped by the ring gear 23. The oil collecting tank 31 is composed of a rib protruding from the inner surface of the first casing 3A toward the second casing 3B (i.e., toward the left) and a rib protruding from the inner surface of the second casing 3B toward the first casing 3A (i.e., toward the right).

[0095] like Figure 1 As shown in FIG. 1 , the oil collecting tank 31 is arranged at a position forward of the pinion gear 22 and at a position higher than the input gear 21. Figure 7 As shown, the oil collecting tank 31 is arranged at a position overlapping with the input gear 21 from above. The oil collecting tank 31 has a bottom wall 311 and a side wall 312.

[0096] The bottom wall 311 is arranged to span the first housing 3A and the second housing 3B. The bottom wall 311 has a first communicating hole 311A ​​and a second communicating hole 311B. The first communicating hole 311A ​​communicates the interior of the oil collecting tank 31 with the first input gear bearing accommodating portion 41A. The first communicating hole 311A ​​uses gravity to send the oil in the oil collecting tank 31 to the first input gear bearing 27A.

[0097] The second communication hole 311B is provided on the left side of the first communication hole 311A ​​and connects the inside of the oil collecting tank 31 with the second input gear bearing accommodating portion 41B. The second communication hole 311B sends the oil in the oil collecting tank 31 to the second input gear bearing 27B by gravity.

[0098] The side wall 312 surrounds the bottom wall 311 from four sides. The side wall 312 has an outflow portion 312A and a third connecting hole 312B. The outflow portion 312A is a portion of the side wall 312 that is lower in height than other portions. The outflow portion 312A is the lowest portion of the side wall 312 and is provided in the right region of the rear side wall of the side wall 312.

[0099] The outflow portion 312A is formed by a part of the rib of the first housing 3A, and is provided at a position overlapping with the main guide member 32 from below. When the liquid level of the oil stored in the oil collecting tank 31 exceeds the height of the outflow portion 312A, the oil flows out from the outflow portion 312A to the outside of the oil collecting tank 31 (specifically, to the right first sub-gear flow path 45A). The outflow direction of the oil in the outflow portion 312A is toward the rear.

[0100] The third communication hole 312B is provided in the left region of the rear side wall of the side wall 312. The third communication hole 312B delivers the oil in the oil collecting tank 31 to the left first sub-gear flow path 45B (see Figure 6 ).

[0101] <Main Boot Component>

[0102] When the ring gear 23 rotates in the forward direction of the vehicle (hereinafter also referred to as the "first direction"), the main guide member 32 sends the oil scraped by the ring gear 23 to the oil collecting tank 31. The main guide member 32 is composed of a rib protruding from the inner surface of the first case 3A toward the axial direction of the input gear 21.

[0103] like Figure 8 As shown, at least a portion of the main guide member 32 overlaps the first gear 221 when viewed from the axial direction of the pinion gear 22. Specifically, the center portion of the main guide member 32 in the oil flow direction is arranged on the right side of the first gear 221.

[0104] Furthermore, at least a portion of the main guide member 32 overlaps with the second gear 222 when viewed in the radial direction of the pinion gear 22. Specifically, the center portion of the main guide member 32 in the oil flow direction overlaps with the second gear 222 from above.

[0105] Furthermore, the main guide member 32 is disposed at a position higher than the first pinion bearing 28A when viewed in the axial direction of the pinion 22. That is, the main guide member 32 extends across the first pinion bearing 28A in the front-rear direction.

[0106] like Figure 5 As shown, the main guide component 32 has an upstream end 321, a downstream end 322, and a guide surface 323. The upstream end 321 and the downstream end 322 are ends in the oil flow direction. The upstream end 321 is arranged at a position rearward and upward of the downstream end 322. Therefore, the main guide component 32 constitutes a flow path for the oil to flow from the upper rear to the lower front.

[0107] like Figure 1 As shown in FIG. 1 , the upstream end 321 is located radially outside the ring gear 23. The upstream end 321 is arranged at a position higher than the ring gear 23, and is arranged at a position lower than the point located above the highest point P1 of the ring gear 23 and the highest point P2 of the first gear 221. In addition, the upstream end 321 is arranged at a position lower than a virtual plane S, wherein the virtual plane S is parallel to the axial direction of the ring gear 23 and includes the highest point P1 of the ring gear 23 and the highest point P2 of the first gear 221.

[0108] The downstream end 322 is arranged above the oil collecting tank 31. In addition, the downstream end 322 is arranged at a position forward of the outflow portion 312A of the oil collecting tank 31.

[0109] The guide surface 323 is a surface for supplying oil to flow toward the oil collecting tank 31. The guide surface 323 constitutes the upper surface of the main guide component 32. Figure 8 As shown, the guide surface 323 is inclined with respect to the axial direction of the pinion gear 22 so as to be lowered as it goes to the left. The above inclination is caused by the draft angle when the first housing 3A is released from the mold.

[0110] like Fig. 9 As shown, the guide surface 323 has a groove 323A and a step 323B. The groove 323A is recessed downward and extends along the axial direction of the ring gear 23. Specifically, the groove 323A extends from the inner surface of the first housing 3A to the buffer portion 35. The groove 323A is arranged between the upstream end 321 of the main guide member 32 and the step 323B.

[0111] The step portion 323B is provided on the downstream side of the groove 323A. The oil overflowing from the groove 323A falls along the step 323B and flows toward the downstream end 322. A portion of the oil reaching the upstream end 321 is Fig. 9 The remaining portion flows to the left (ie, flows toward the buffer portion 35 ) as shown by the arrow in FIG. 3 , and the remaining portion flows over the groove 323A toward the downstream end 322 .

[0112] <Guide>

[0113] The guide portion 33 is disposed offset from the main guide member 32 in the axial direction (ie, the left-right direction) of the ring gear 23 , and guides the oil to the main guide member 32 .

[0114] The guide portion 33 is a recessed portion provided on the inner surface of the first housing 3A. The guide portion 33 is provided at a position to the right of the main guide member 32 and is recessed to the right. The guide portion 33 extends in the front-rear direction and guides the oil forward. The guide portion 33 forms an oil flow path that is continuous with the groove 323A of the main guide member 32.

[0115] like Figure 5 As shown, the guide portion 33 extends from a first end 331 to a second end 332. The first end 331 is a front end of the guide portion 33. The first end 331 is connected to the upstream end 321 of the main guide member 32 from above.

[0116] The second end 332 is the rear end of the guide portion 33. When viewed from the axial direction of the ring gear 23, the second end 332 is disposed at a position overlapping with the ring gear 23. Specifically, when viewed from the axial direction of the ring gear 23, the second end 332 overlaps with a portion A1 (see FIG. 1 ) before the ring gear 23 reaches the highest point P1 of the ring gear 23 when the ring gear 23 rotates in the first direction. Figure 1 ) or overlaps with the highest point P1 of the ring gear 23. The portion A1 is a region on the outer peripheral surface of the ring gear 23 where the rotation angle θ from the highest point P1 is less than 10°.

[0117] <Hanging Wall>

[0118] like Figure 3 As shown, the vertical wall 34 extends downward from the second end 332 of the guide portion 33 toward the window portion 245 of the differential case 24. The vertical wall 34 is composed of a rib protruding from the inner surface of the first case 3A.

[0119] like Figure 5 As shown, the vertical wall 34 has a first surface 341 and a second surface 342 extending in the vertical direction. The first surface 341 faces rearward, and the second surface 342 faces forward. The oil reaching a position lower than the second end 332 of the guide portion 33 is guided to the window portion 245 by the first surface 341.

[0120] <Buffer>

[0121] Fig. 9 The buffer portion 35 shown in the figure sends part of the oil flowing through the main guide member 32 to the second differential case bearing 29B. The buffer portion 35 is composed of a rib protruding from the inner surface of the second case 3B in the axial direction of the input gear 21.

[0122] The buffer portion 35 has a bottom wall 351 and a side wall 352. The bottom wall 351 is connected to the groove 323A of the main guide member 32 in the axial direction of the ring gear 23. That is, oil is supplied to the buffer portion 35 from the groove 323A.

[0123] The side wall 352 surrounds the bottom wall 351 from the front, rear, and left. The side wall 352 has an outflow portion 352A. The outflow portion 352A is a portion of the side wall 352 that is lower than other portions. The outflow portion 352A is the lowest portion of the side wall 352 and is provided on the rear side wall of the side wall 352.

[0124] The outflow portion 352A is provided on the left side of the upstream end 321 of the main guide member 32 and allows the oil in the buffer portion 35 to flow toward the second differential case bearing 29B. The highest point of the outflow portion 352A is lower than the highest point of the groove 323A of the main guide member 32.

[0125] When the liquid level of the oil stored in the buffer portion 35 exceeds the height of the outflow portion 352A, the oil flows out of the outflow portion 352A to the outside of the buffer portion 35. The outflow direction of the oil in the outflow portion 352A is toward the rear. That is, the outflow direction of the oil from the buffer portion 35 is opposite to the flow direction of the oil flowing in the main guide portion 32.

[0126] <Lower guide member>

[0127] Figure 4 The lower guide member 36 shown faces the ring gear 23 from the radially outer side at a position lower than the rotation axis L3 of the ring gear 23 , and faces the first gear 221 from the radially outer side at a position lower than the rotation axis L2 of the first gear 221 .

[0128] The lower guide member 36 is formed by a rib (see FIG. 1 ) protruding from the inner surface of the first housing 3A toward the second housing 3B (ie, toward the left side). Figure 1 ) and a rib protruding from the inner surface of the second housing 3B toward the first housing 3A (ie, toward the right side).

[0129] Specifically, the lower guide member 36 includes a rear portion 361 extending along the outer edge of the ring gear 23, and a front portion 362 extending forward from the front end of the rear portion 361. The rear portion 361 is opposed to the front lower portion of the ring gear 23. The front portion 362 is opposed to the lower portion of the first gear 221. The front portion 362 reaches the first input gear bearing accommodating portion 41A and the second input gear bearing accommodating portion 41B.

[0130] The oil scraped when the ring gear 23 rotates in the rearward direction of the vehicle (hereinafter also referred to as the “second direction”) is sent to the front portion 362 . The oil sent to the front portion 362 is further scraped by the first gear 221 .

[0131] like Figure 5 and Figure 6As shown, the lower guide member 36 divides the internal space (i.e., the oil storage space) of the gear box 3 into a front portion 3G and a rear portion 3H. In addition, the lower end (i.e., the rear end) of the lower guide member 36 is separated from the lower surface of the internal space of the gear box 3. The gap between the lower end of the lower guide member 36 and the lower surface of the internal space of the gear box 3 constitutes a flow path for the oil to flow from the front portion 3G to the rear portion 3H.

[0132] Since the oil storage space is partitioned by the lower guide member 36 as described above, the amount of oil immersed in the ring gear 23 decreases when the vehicle is running, and the stirring resistance of the ring gear 23 also decreases accordingly.

[0133] <Reverse guide component>

[0134] When the ring gear 23 rotates in the second direction, Figure 6 The reverse guide member 37 shown sends the oil scraped by the ring gear 23 and further scraped by the first gear 221 at the lower guide member 36 to the oil collecting tank 31. The reverse guide member 37 is composed of a rib protruding from the inner surface of the second case 3B in the axial direction of the input gear 21.

[0135] like Fig.10 As shown, the reverse guide member 37 is arranged at a position overlapping with the first gear 221 in the axial direction of the pinion 22. Specifically, the upstream side portion of the reverse guide member 37 in the oil flow direction is arranged on the left side of the first gear 221.

[0136] The reverse guide member 37 has an upstream end 371, a downstream end 372, and a guide surface 373. The upstream end 371 and the downstream end 372 are ends in the oil flow direction. Figure 6 As shown, the upstream end 371 is arranged at a position rearward and upward of the downstream end 372. Therefore, the reverse guide member 37 forms a flow path for oil to flow from the rear upper side to the front lower side. In addition, the upstream end 371 is arranged at a position higher than the second sub-gear bearing accommodating portion 42B and is arranged at a position forward of the rotation axis L2 of the sub-gear 22.

[0137] The downstream end 372 is disposed above the oil collecting tank 31. In addition, the downstream end 372 is connected to the rear side wall of the side wall 312 of the oil collecting tank 31.

[0138] The guide surface 373 is a surface for supplying oil to flow toward the oil collecting tank 31. The guide surface 373 constitutes the upper surface of the reverse guide member 37. Fig.10 As shown, the width of the guide surface 373 perpendicular to the oil flow direction (ie, the width in the left-right direction) increases toward the oil collecting tank 31 .

[0139] <Reverse vertical wall>

[0140] Figure 6The reverse vertical wall 38 shown supplies the oil scraped by the ring gear 23 when the ring gear 23 rotates in the second direction to the second differential case bearing 29B.

[0141] The reverse vertical wall 38 is formed by a part (specifically, the rear wall) of the recessed portion provided on the inner surface of the second case 3B. The reverse vertical wall 38 has a wall surface facing forward. The reverse vertical wall 38 is arranged at a position rearward of the buffer portion 35 and is arranged above the second differential case bearing accommodating portion 43B.

[0142] <Bearing Accommodation Section>

[0143] Figure 5 The first input gear bearing accommodating portion 41A, the first pinion bearing accommodating portion 42A, and the first differential case bearing accommodating portion 43A shown accommodate the first input gear bearing 27A, the first pinion bearing 28A, and the first differential case bearing 29A, respectively.

[0144] The first input gear bearing accommodating portion 41A, the first sub-gear bearing accommodating portion 42A, and the first differential case bearing accommodating portion 43A are recessed portions provided on the inner surface of the first case 3A. The first input gear bearing accommodating portion 41A has an opening through which the motor shaft is inserted. The first differential case bearing accommodating portion 43A has an opening through which the first output shaft is inserted. Oil seals are disposed at the above-mentioned openings.

[0145] Figure 6 The second input gear bearing accommodating portion 41B, the second pinion bearing accommodating portion 42B, and the second differential case bearing accommodating portion 43B shown accommodate the second input gear bearing 27B, the second pinion bearing 28B, and the second differential case bearing 29B, respectively.

[0146] The second input gear bearing accommodating portion 41B, the second sub-gear bearing accommodating portion 42B, and the second differential case bearing accommodating portion 43B are recessed portions provided on the inner surface of the second case 3B. The second differential case bearing accommodating portion 43B has an opening through which the second output shaft is inserted. An oil seal is disposed at the opening.

[0147] <Flow path for the first secondary gear>

[0148] Figure 5 The right first pinion flow passage 45A shown sends the oil flowing out from the outflow portion 312A of the oil collecting tank 31 to the first pinion bearing 28A. The right first pinion flow passage 45A causes the oil to flow rearward toward the first pinion bearing 28A.

[0149] The right first pinion flow path 45A is formed by a recess and a rib provided on the inner surface of the first case 3A. The right first pinion flow path 45A extends from the outflow portion 312A of the oil collecting tank 31 to the first pinion bearing accommodating portion 42A.

[0150] Figure 6 The left first pinion flow passage 45B shown sends oil from the oil collecting tank 31 to the second pinion bearing 28B. The left first pinion flow passage 45B allows the oil to flow rearward toward the second pinion bearing 28B.

[0151] The left first pinion flow passage 45B is a communication hole provided in the second case 3B. The left first pinion flow passage 45B is a communication hole that allows the third communication hole 312B of the oil collecting tank 31 and the second pinion bearing accommodating portion 42B to communicate with each other.

[0152] <Flow path for the second gear>

[0153] Figure 5 The second secondary gear flow passage 46 shown in the figure directly delivers the oil scraped by the ring gear 23 to the first secondary gear bearing 28A. The second secondary gear flow passage 46 allows the oil to flow forward toward the first secondary gear bearing 28A. The second secondary gear flow passage 46 is formed by a rib protruding from the inner surface of the first case 3A.

[0154] The second sub-gear flow path 46 is arranged at a position lower than the upstream end 321 of the main guide member 32. Specifically, the second sub-gear flow path 46 is entirely arranged below the main guide member 32. When viewed from the axial direction of the ring gear 23, at least a portion of the second sub-gear flow path 46 overlaps with the ring gear 23. The second sub-gear flow path 46 extends from the lower region and the front region of the upstream end 321 of the main guide member 32 to the first sub-gear bearing accommodating portion 42A.

[0155] <Differential case flow path>

[0156] The differential case flow passage 47 sends oil from the first pinion bearing 28A to the first differential case bearing 29A. The differential case flow passage 47 is a communication hole provided in the first case 3A.

[0157] The differential case flow path 47 is disposed below the second pinion flow path 46. The differential case flow path 47 allows the first pinion bearing accommodating portion 42A and the first differential case bearing accommodating portion 43A to communicate with each other.

[0158] <Parking lock mechanism>

[0159] Figure 1 The parking lock mechanism 5 shown is switchable between a locked state in which the rotation of the input gear 21 is restricted and a released state in which the rotation is permitted.

[0160] <Oil Flow>

[0161] like Figure 5 As shown by the arrow in , when the vehicle moves forward (ie, when the ring gear 23 rotates in the first direction D1 ), the oil O stored in the rear portion 3H of the gear case 3 is scraped up by the ring gear 23 toward the main guide member 32 .

[0162] The oil O scraped by the ring gear 23 reaches the main guide member 32 and is sent to the oil collecting tank 31 by the main guide member 32. In addition, due to the rotation direction of the ring gear 23, a part of the oil O is sent to the guide portion 33. The oil O sent to the guide portion 33 is sent to the main guide member 32. The oil O sent to the vertical wall 34 is guided by the vertical wall 34 and supplied to the window portion 245 of the differential case 24.

[0163] The oil O sent to the oil collecting tank 31 is supplied to the first input gear bearing 27A and the oil seal of the first input gear bearing accommodating portion 41A from the first communicating hole 311A ​​provided in the bottom wall 311. In addition, the oil O overflowing from the outflow portion 312A of the oil collecting tank 31 is supplied to the first sub-gear bearing 28A from the right first sub-gear flow path 45A.

[0164] In addition, a part of the oil scraped by the ring gear 23 is supplied to the first sub-gear bearing 28A through the second sub-gear flow path 46 instead of the oil collecting tank 31. When the rotation speed of the ring gear 23 is low, the amount of oil O scraped by the ring gear 23 that reaches the main guide member 32 decreases, while the amount that reaches the second sub-gear flow path 46 increases.

[0165] The oil supplied to the first pinion bearing 28A is supplied to the first differential case bearing 29A, the oil seal of the first differential case bearing accommodating portion 43A, and the sliding portion between the first shaft portion 243 and the first output shaft via the differential case flow path 47. The oil O supplied to the first differential case bearing 29A is returned to the rear portion 3H of the gear case 3.

[0166] like Figure 6 As shown by the arrow in , when the vehicle moves forward, on the second housing 3B side, the oil O sent to the oil collecting tank 31 is supplied to the second input gear bearing 27B from the second connecting hole 311B provided on the bottom wall 311. In addition, the oil O in the oil collecting tank 31 is supplied to the second sub-gear bearing 28B from the third connecting hole 312B via the left first sub-gear flow path 45B.

[0167] In addition, a part of the oil O scraped up by the ring gear 23 to the main guide member 32 is supplied to the buffer portion 35 through the groove 323A of the main guide member 32. The oil O overflowing from the outflow portion 352A of the buffer portion 35 is supplied to the second differential case bearing 29B, the oil seal of the second differential case bearing accommodating portion 43B, and the sliding portion between the second shaft portion 244 and the second output shaft. In addition, when the vehicle moves forward, no oil flows through the reverse guide member 37.

[0168] like Fig.11 As shown by the arrow in , when the vehicle is reversed (i.e., when the ring gear 23 rotates in the second direction D2), the oil O accumulated in the rear portion 3H of the gear case 3 is scraped forward along the lower guide member 36 by the ring gear 23. The oil O scraped by the ring gear 23 to the lower guide member 36 is scraped by the first gear 221 toward the reverse guide member 37.

[0169] The oil O scraped by the first gear 221 reaches the reverse guide member 37, and is sent to the oil collecting tank 31 by the reverse guide member 37. In addition, a part of the oil O scraped by the first gear 221 splashes and reaches the reverse vertical wall 38, and is supplied along the wall surface of the reverse vertical wall 38 to the second differential case bearing 29B, the oil seal of the second differential case bearing accommodating portion 43B, and the sliding portion between the second shaft portion 244 and the second output shaft.

[0170] like Fig.12 As shown by the arrow in , on the first case 3A side, a part of the oil O scraped by the ring gear 23 splashes and reaches the second surface 342 of the vertical wall 34 , and is supplied to the window portion 245 of the differential case 24 .

[0171] In addition, the oil O sent to the oil collecting tank 31 during reverse travel is supplied to each bearing and oil seal through the same flow path as during forward travel. In addition, when the vehicle is reverse travel, no oil flows through the main guide member 32.

[0172] [1-2. Effect]

[0173] According to the embodiments described in detail above, the following effects can be obtained.

[0174] (1a) Of the oil scraped up by the ring gear 23, the oil pushed out in the axial direction of the ring gear 23 is supplied from the guide portion 33 to the main guide member 32. Therefore, a decrease in the amount of oil supplied to the oil collecting tank 31 can be suppressed.

[0175] (1b) The oil is collected in the guide portion 33 by the rotation direction of the ring gear 23 , so that the effect of suppressing the reduction in the amount of oil supplied to the oil collecting tank 31 can be promoted.

[0176] (1c) The second end 332 of the guide portion 33 overlaps with the portion A1 before reaching the highest point P1 of the ring gear 23, or overlaps with the highest point P1, so that the oil that has been separated from the teeth reaching the highest point P1 of the ring gear 23 due to gravity can easily reach the guide portion 33. As a result, the effect of suppressing the reduction in the amount of oil supplied to the oil collecting tank 31 can be promoted.

[0177] (1d) Since the guide portion 33 is a recessed portion provided on the inner surface of the gear case 3, the shape of the guide portion 33 can be simplified and the cost of forming the guide portion 33 can be reduced.

[0178] (1e) The oil that cannot reach the guide member 32 via the guide portion 33 can be efficiently supplied to the interior of the differential case 24 via the vertical wall 34 .

[0179] [2. Other embodiments]

[0180] The embodiments of the present disclosure are described above, but the present disclosure is not limited to the above embodiments and can take various forms.

[0181] (2a) In the transmission device of the above embodiment, the gearbox may not have the first housing and the second housing. In other words, the gearbox may not be composed of components separated along the axial direction of the input gear. In addition, the input gear, the first gear, the second gear, and the ring gear may not be helical gears.

[0182] (2b) In the transmission device of the above embodiment, when viewed from the axial direction of the gear ring, the second end of the guide portion may not overlap with a portion before reaching the highest point of the gear ring, or may not overlap with the highest point of the gear ring. For example, the second end of the guide portion may be arranged at a position lower than the portion before the highest point of the gear ring or the highest point.

[0183] (2c) In the transmission device of the above embodiment, the guide portion may not be formed by a recessed portion provided on the inner surface of the gear case. For example, the guide portion may be formed by a rib protruding from the inner surface of the gear case.

[0184] (2d) In the transmission device of the above embodiment, the gear case may not have a vertical wall. In other words, the oil may be supplied to the window portion of the differential case through a flow path other than the vertical wall.

[0185] (2e) In the transmission device of the above embodiment, the rotation axis of the pinion gear may not be located above the rotation axis of the input gear and the rotation axis of the ring gear.

[0186] (2f) The function of one component in the above-mentioned embodiment may be shared by multiple components, or the functions of multiple components may be integrated into one component. In addition, a part of the structure of the above-mentioned embodiment may be omitted. In addition, at least a part of the structure of the above-mentioned embodiment may be added to the structure of the above-mentioned other embodiment, or at least a part of the structure of the above-mentioned embodiment may be replaced with the structure of the above-mentioned other embodiment, etc. In addition, all the methods included in the technical idea determined by the sentences recorded in the claims are embodiments of the present disclosure.

Claims

1. A transmission device, comprising a transmission mechanism and a gear box accommodating the transmission mechanism, wherein the transmission device is characterized in that the transmission mechanism has: Input gear; a pinion gear having an axis of rotation parallel to the axis of rotation of the input gear; a ring gear having a rotation axis parallel to the rotation axis of the input gear; a differential housing, the differential housing being fixed to the ring gear; A differential mechanism, wherein the differential mechanism is arranged inside the differential housing; an input gear bearing, the input gear bearing rotatably supporting the input gear; a pinion bearing that rotatably supports the pinion; and a differential case bearing that rotatably supports the differential case, and The secondary gear has: a first gear meshing with the input gear; as well as a second gear, wherein the outer diameter of the second gear is smaller than the outer diameter of the first gear, the second gear is arranged concentrically with the first gear, and meshes with the ring gear, The gearbox has: Oil collecting tank; a guide component, wherein the guide component sends the oil scraped by the gear ring to the oil collecting tank; as well as a guide portion, the guide portion being arranged offset from the guide member in the axial direction of the ring gear and guiding the oil to the guide member, The guide member has an upstream end and a downstream end in the flow direction of the oil, The upstream end is located radially outside the gear ring, The guide portion extends from a first end to a second end, wherein the first end is connected to the upstream end of the guide member, and the second end overlaps with the ring gear when viewed in the axial direction of the ring gear.

2. The transmission device according to claim 1, characterized in that: The ring gear is a helical gear with a hand direction, and when the ring gear rotates in a direction to scrape the oil toward the guide member, the ring gear transports the oil toward the guide portion.

3. The transmission device according to claim 1 or 2, characterized in that: When viewed in the axial direction of the ring gear, the second end of the guide portion overlaps with a portion before the ring gear reaches a highest point when the ring gear rotates in a direction to scrape the oil toward the guide member, or overlaps with a highest point of the ring gear.

4. The transmission device according to claim 1 or 2, characterized in that: The guide portion is a recessed portion provided on an inner surface of the gear case.

5. The transmission device according to claim 1 or 2, characterized in that: The differential case has a window portion communicating with the interior. The gear case includes a vertical wall extending downward from the second end of the guide portion toward the window portion.

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