Drive device

Abstract

[Problem] To prevent insufficient lubrication of a gear and a rotary shaft disposed inside a casing. [Solution] A drive device according to the present invention comprises: a motor that is a drive source; a power transmission mechanism that transmits power of the motor to a drive wheel; and a casing that accommodates the motor and the power transmission mechanism. The power transmission mechanism includes an input shaft to which power is input from the motor, an output shaft that transmits power from the motor input via a gear to the drive wheel, and an intermediate shaft provided between the input shaft and the output shaft. The intermediate shaft is located above the input shaft and the output shaft in a vertical direction as viewed from an axial direction of the power transmission mechanism, and includes a first gear provided on the input shaft, a second gear provided on the intermediate shaft and meshing with the first gear, a third gear disposed side by side with the second gear in the axial direction of the intermediate shaft, and a fourth gear provided on the output shaft and meshing with the third gear. The casing includes, above the second gear, a catch tank that stores oil. The catch tank includes a supply unit that supplies the stored oil to the second gear. The supply unit is formed with an inlet for oil on the fourth gear side and an outlet for oil above the second gear, as viewed from the axial direction of the power transmission mechanism.

Description

Drive unit

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

[0002] In the vehicle drive transmission device disclosed in Patent Document 1, a catch tank is provided in the casing to receive and temporarily store oil that is scooped up and splashed by the gears.

[0003] The oil stored in the catch tank flows through a communication hole formed in the catch tank and is guided to an oil passage formed in the casing to lubricate various gears, power input shafts, rotor shafts, etc. located inside the casing.

[0004] International Publication No. 2024 / 018963

[0005] The drive device disclosed in Patent Document 1 is configured so that oil stored in the catch tank circulates inside the casing, but there are some places inside the casing that the oil cannot easily reach.

[0006] Therefore, an object of the present invention is to guide oil to places inside the casing that are difficult for oil to reach, thereby preventing insufficient lubrication of gears and rotating shafts arranged inside the casing.

[0007] According to one aspect of the present invention, there is provided a drive device including a motor as a drive source, a power transmission mechanism that transmits power of the motor to drive wheels, and a casing that houses the motor and the power transmission mechanism, wherein the power transmission mechanism includes an input shaft to which power is input from the motor, an output shaft that transmits the power input from the motor via gears to the drive wheels, and an intermediate shaft provided between the input shaft and the output shaft, and when viewed in the axial direction of the power transmission mechanism, the intermediate shaft is located vertically above the input shaft and the output shaft, and a first gear provided on the input shaft a second gear provided on the intermediate shaft and meshing with the first gear, a third gear arranged alongside the second gear in the axial direction of the intermediate shaft, and a fourth gear provided on the output shaft and meshing with the third gear, wherein the casing has a catch tank above the second gear for storing oil, the catch tank having a supply section that supplies the stored oil to the second gear, and the supply section has an oil inlet formed on the fourth gear side when viewed in the axial direction of the power transmission mechanism, and an oil outlet formed above the second gear.

[0008] According to one aspect of the present invention, oil can be directed to places inside the casing that are difficult for oil to reach, preventing insufficient lubrication of gears and rotating shafts arranged inside the casing.

[0009] FIG. 1 is a rear view of the drive unit according to this embodiment. FIG. 2 is a right side view of the drive unit according to this embodiment. FIG. 3 is a view showing the inner surface of the case of the drive unit. FIG. 4 is a view showing the drive unit with the case removed from the housing. FIG. 5 is a view of the drive unit from above, showing the gears housed in the housing. FIG. 6 is an enlarged perspective view of the main part of the periphery of a part on the case side of the catch tank shown in FIG. 3. FIG. 7 is a schematic view of the drive unit from above, showing the positional relationship between the gears housed in the housing and the catch tank.

[0010] A driving device 10 according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

[0011] Fig. 1 is a rear view of the drive unit 10 according to this embodiment. Fig. 2 is a right side view of the drive unit 10 according to this embodiment. Fig. 3 is a view showing the inner surface of the case 24 of the drive unit 10. Fig. 4 is a view showing the drive unit 10 with the case 24 removed from the housing 20. Fig. 5 is a view of the gears housed in the housing 20 as seen from above the drive unit 10.

[0012] In the drawings, the upward direction U, downward direction D, forward direction FR, rearward direction RR, leftward direction L, and rightward direction R indicate directions when the device is mounted on the vehicle. The leftward direction L and rightward direction R are the left and right directions when facing the direction of travel of the vehicle moving forward.

[0013] 1 and 2 , a drive unit 10 is used in, for example, an electric vehicle. A casing 12 of the drive unit 10 has a housing 20, a cover 22 attached to one end of the housing 20, and a case 24 attached to the other end of the housing 20. An inverter case 16 is disposed on top of the casing 12.

[0014] When mounted on a vehicle, the drive unit 10 is disposed so that the case 24 faces the left side L of the vehicle and the cover 22 faces the right side R of the vehicle. When mounted on a vehicle, the inverter case 16 is located above the casing 12 at U. The inverter case 16 houses an inverter (not shown), and the housing 20 houses a motor (not shown) that operates on power from the inverter and constitutes a drive source.

[0015] 3 and 4, a housing recess 32 that constitutes the mechanism accommodating portion 30 is formed at the end of the housing 20 on the case 24 side (see FIG. 4). The end face of a housing recess peripheral wall 34 that surrounds the housing recess 32 constitutes a mating surface that is butted against the case 24.

[0016] (Case) A case recess 42 is formed on the inner surface of the case 24 that constitutes the housing 20 side, and together with the housing recess 32, constitutes the mechanism accommodating portion 30 (see FIG. 3). An end face of a case recess peripheral wall 44 that surrounds the case recess 42 constitutes a mating surface that abuts against an end face of the housing recess peripheral wall 34 of the housing 20. When the case recess peripheral wall 44 abuts against the housing recess peripheral wall 34 of the housing 20, the mechanism accommodating portion 30, consisting of the housing recess 32 and the case recess 42, is formed between the housing 20 and the case 24.

[0017] 4, a power transmission mechanism 50 is provided in the mechanism housing 30. The power transmission mechanism 50 transmits power from the motor to drive wheels (not shown) provided on the vehicle. The power transmission mechanism 50 includes an input shaft 52 to which power is input from the motor, a gear 54 provided on the input shaft 52, and an output shaft 58 that transmits the power from the motor input via the gear 54 to the drive wheels.

[0018] 4 and 5, the input shaft 52 extends from the housing recess wall surface 32B of the housing recess 32. The input shaft 52 is rotatably supported by the housing recess wall surface 32B. The input shaft 52 is disposed in a position of the drive unit 10 closer to the rear (RR) of the vehicle. The input shaft 52 extends in the left-right direction of the drive unit 10.

[0019] (Intermediate Shaft) An intermediate shaft 56 is disposed in the drive unit 10 at a position closer to the front (FR) side of the vehicle than the input shaft 52 and on the upper U side than the input shaft 52. The intermediate shaft 56 extends in the left-right direction so as to be parallel to the input shaft 52. The intermediate shaft 56 is rotatably supported on the housing recess wall surface 32B.

[0020] (Output Shaft) The output shaft 58 described above is disposed in the drive unit 10 at a position further forward (FR) of the vehicle than the intermediate shaft 56 and on the D side below the intermediate shaft 56. The output shaft 58 is disposed on the D side below the input shaft 52. The output shaft 58 extends in the left-right direction so as to be parallel to the intermediate shaft 56. The output shaft 58 is rotatably supported on the housing recess wall surface 32B.

[0021] One end of the output shaft 58 extends further toward the left L of the vehicle than the casing 12. A drive wheel (not shown) is provided at one end of the output shaft 58. The other end of the output shaft 58 extends further toward the right R of the vehicle than the casing 12. A drive wheel (not shown) is fixed to the other end of the output shaft 58.

[0022] 4 and 5 , the gear 54 provided on the input shaft 52 is made up of a first gear 60 that rotates together with the input shaft 52 and a parking gear 62. The first gear 60 and the parking gear 62 are arranged side by side in the axial direction of the input shaft 52. The parking gear 62 has a larger diameter than the first gear 60.

[0023] The first gear 60 is disposed in the case recess 42. The parking gear 62 is disposed closer to the housing than the first gear 60, with a portion of the parking gear 62 disposed in the case recess 42 and another portion of the parking gear 62 disposed in the housing recess 32.

[0024] The first gear 60 transmits the rotation of the input shaft 52 to the intermediate shaft 56. A plurality of engagement recesses 62B are formed at equal intervals on the circumferential surface of the parking gear 62. An engagement claw 64B of a lock plate 64 journaled on a shaft 32C of the housing recess wall surface 32B can engage with the engagement recesses 62B. The lock plate 64 is rotated by an actuator 66 when a shift selector (not shown) on the driver's seat is set to park. When the lock plate 64 rotates, the engagement claw 64B engages with the engagement recess 62B, preventing rotation of the input shaft 52.

[0025] 5, the intermediate shaft 56 is provided with a second gear 70 and a third gear 72 that rotate together with the intermediate shaft 56. The third gear 72 is disposed closer to the housing recess wall surface 32B than the second gear 70. The second gear 70 and the third gear 72 are disposed side by side in the axial direction of the intermediate shaft 56. The second gear 70 is disposed on the case 24 side, and the third gear 72 is disposed on the housing 20 side.

[0026] The second gear 70 meshes with the first gear 60 provided on the input shaft 52. The second gear 70 has a larger diameter than the first gear 60, and transmits the rotation of the input shaft 52 to the intermediate shaft 56 after reducing the rotation speed. The third gear 72 has a smaller diameter than the second gear 70. The third gear 72 transmits the rotation of the intermediate shaft 56 to the output shaft 58.

[0027] 4 and 5, the output shaft 58 is provided with a fourth gear 76 that rotates together with the output shaft 58. The fourth gear 76 constitutes a ring gear of the differential gear.

[0028] The fourth gear 76 meshes with the third gear 72. The fourth gear 76 has a larger diameter than the third gear 72, and transmits the rotation of the intermediate shaft 56 to the output shaft 58 at a reduced speed.

[0029] In this embodiment, the first gear 60, the second gear 70, the third gear 72, and the fourth gear 76 are so-called helical gears, in which the tooth trace of a spur gear is twisted and formed into a spiral shape.

[0030] (Mechanism Housing Section) A gear arrangement area 80 is formed in the mechanism housing section 30 of the casing 12, in which the first gear 60, the parking gear 62, the second gear 70, the third gear 72, and the fourth gear 76 are arranged. As shown in Figures 3 and 4, the mechanism housing section 30 of the casing 12 is provided with a catch tank 100 above the second gear 70 that stores oil.

[0031] (Catch Tank) Next, the catch tank 100 will be described with reference to Figures 3, 4, and 6. Figure 6 is an enlarged perspective view of a main part of the periphery of a part of the case 24 side of the catch tank 100 shown in Figure 3, viewed obliquely from below.

[0032] As shown in Figure 4, the housing 20 is formed with a housing rib 110 that constitutes the catch tank 100. The housing rib 110 protrudes from the housing 20 toward the case 24, starting from the inner surface of the housing 20. The top end face of the housing rib 110 is formed so as to be flush with the end face of the peripheral wall 34 of the housing recess.

[0033] The housing rib 110 includes a first housing rib 111 and a second housing rib 112 .

[0034] The first housing rib 111 branches off from the housing recess peripheral wall 34 and is formed continuously to face the outer periphery of the fourth gear 76. The second housing rib 112 is formed continuously to face the outer periphery of the second gear 70.

[0035] Here, the height from the base of the end of the second housing rib 112 opposite to the end connected to the first housing rib 111 is lower than the top end face. The end of the second housing rib 112 and the housing recess peripheral wall 34 are not connected on the same plane.

[0036] In this embodiment, a guide rib 113 is formed adjacent to the housing rib 110 that forms the catch tank 100. The guide rib 113 protrudes from the housing 20 toward the case 24, starting from the inner surface of the housing 20.

[0037] The guide rib 113 branches off from the housing recess peripheral wall 34 and is formed from the housing recess peripheral wall 34 toward the intermediate shaft 56 along the approximate radial direction of the second gear 70. The top end face of the guide rib 113 is formed to be flush with the end face of the housing recess peripheral wall 34.

[0038] 3 and 6, case 24 is formed with a case rib 120 that constitutes catch tank 100. Case rib 120 protrudes from the case 24 toward housing 20, starting from the inner surface of case 24. A top end surface 120S of case rib 120 is formed so as to be flush with the end surface of the peripheral wall 44 of the case recess.

[0039] The case rib 120 includes a first case rib 121 and a second case rib 122 .

[0040] The first case rib 121 branches off from the case recess peripheral wall 44 and is formed continuously so as to face the outer periphery of the fourth gear 76. The second case rib 122 is formed continuously so as to face the outer periphery of the second gear 70.

[0041] The top end face of the housing rib 110 is formed to be flush with the end face of the housing recess peripheral wall 34, and the top end face 120S of the case rib 120 is formed to be flush with the end face of the case recess peripheral wall 44.

[0042] 6, second case rib 122 has low rib portion 123 whose height from the base is lower than top end face 120S. Low rib portions 123 formed on housing rib 110 and case rib 120 do not abut on each other even when the end face of case recess peripheral wall 44 and the end face of housing recess peripheral wall 34 are butted against each other, forming opening 101.

[0043] Therefore, when the end face of the case recess peripheral wall 44 and the end face of the housing recess peripheral wall 34 are butted together, a catch tank 100 is formed by the housing rib 110 and the case rib 120, and an opening 101 communicating with the catch tank 100 is formed near the base of the second case rib 122, and a guide rib 113 is formed next to the opening 101.

[0044] The opening 101 functions as an inlet for guiding oil scooped up by the fourth gear 76 to the catch tank 100 when the drive unit 10 is driven.

[0045] Catch tank 100 has a supply unit 130 that supplies the stored oil to the second gear. When viewed from the axial direction of each shaft included in power transmission mechanism 50, supply unit 130 has an oil inlet 131 formed on the fourth gear 76 side and an oil outlet 132 formed above second gear 70. In addition, an oil path 133 is formed between oil inlet 131 and oil outlet 132. In other words, supply unit 130 constitutes a guide path for guiding oil stored in catch tank 100 to mechanism housing unit 30.

[0046] Therefore, oil inlet 131 in supply unit 130 is an inlet to oil path 133, which serves as a guide path, and oil outlet 132 is an outlet for oil that has passed through oil path 133 to mechanism accommodating unit 30. In this embodiment, oil inlet 131 of supply unit 130 is provided at the joining position of first case rib 121 and second case rib 122, which extend diagonally downward from each other, i.e., at the bottom of catch tank 100 (see FIG. 3 ), and oil outlet 132 of supply unit 130, i.e., oil outlet 132 from catch tank 100, is formed above the second gear.

[0047] 7 is a schematic diagram of the drive unit 10 viewed from above, illustrating the positional relationship between the gears housed in the housing 20 and the catch tank 100. In FIG. 7, the catch tank 100, the supply portion 130 formed in the catch tank 100, the opening 101, and the guide rib 113 are indicated by virtual lines (two-dot chain lines).

[0048] 7 indicates the rotation direction of the input shaft 52 when the vehicle moves forward. At this time, the intermediate shaft 56 rotates in the opposite direction to the input shaft 52, and the output shaft 58 rotates in the same direction as the input shaft 52. The black arrow in Fig. 7 indicates the scattering direction of oil scooped up by the third gear 72 and the fourth gear 76 when the vehicle moves forward.

[0049] In the case where the first gear 60, the second gear 70, the third gear 72, and the fourth gear 76 are helical gears, when the vehicle is moving forward, as shown in FIG. 7, the oil scooped up by the fourth gear 76 tends to splash toward the housing 20 due to the twisting of the tooth trace.

[0050] As shown in Figures 6 and 7, an opening 101 serving as an oil inlet to the catch tank 100 is formed above the fourth gear 76 and on the housing 20 side, so that the oil scooped up by the fourth gear 76 can be easily taken into the catch tank 100.

[0051] Furthermore, in the drive unit 10 according to this embodiment, some of the oil that is scooped up by the third gear 72 attached to the intermediate shaft 56 and splashed toward the housing 20 bounces off the guide rib 113, making it easier for the oil to be taken into the opening 101 of the catch tank 100 (shown by arrow O in Figure 4).

[0052] The oil taken into the catch tank 100 flows from the oil inlet 131 through the oil path 133 and is guided above the second gear 70 from the oil outlet 132 .

[0053] (Functions and Effects) The main functions and effects of the drive device 10 configured as above will be summarized below.

[0054] (1) A drive unit 10 including a motor as a drive source, a power transmission mechanism 50 that transmits the power of the motor to drive wheels, and a casing 12 that houses the motor and the power transmission mechanism 50. The power transmission mechanism 50 includes an input shaft 52 to which power is input from the motor, an output shaft 58 that transmits the power from the motor input via gears to the drive wheels, and an intermediate shaft 56 provided between the input shaft 52 and the output shaft 58. When viewed from the axial direction of the power transmission mechanism 50, the intermediate shaft 56 is located higher in the vertical direction U than the input shaft 52 and the output shaft 58. A first gear 60 provided on the input shaft 52 and the intermediate shaft 56 are provided in the casing 12. The power transmission mechanism 50 includes a second gear 70 provided on the intermediate shaft 56 and meshing with the first gear 60, a third gear 72 arranged alongside the second gear 70 in the axial direction of the intermediate shaft 56, and a fourth gear 76 provided on the output shaft 58 and meshing with the third gear 72. The casing 12 includes a catch tank 100 for storing oil above the second gear 70, and the catch tank 100 has a supply section 130 for supplying the stored oil to the second gear 70. The supply section 130 has an oil inlet 131 formed on the fourth gear 76 side when viewed from the axial direction of the power transmission mechanism 50, and an oil outlet 132 formed above the second gear 70.

[0055] According to this configuration, the catch tank 100 provided above the second gear 70 has a supply section 130, and the oil inlet 131 of the supply section 130 is formed on the fourth gear 76 side of the catch tank 100, so that the oil scooped up by the fourth gear 76 easily flows into the oil inlet 131 of the supply section 130.

[0056] Additionally, an oil outlet 132 is formed in the catch tank 100 above the second gear 70. Therefore, oil taken into the fourth gear 76 side of the catch tank 100 can be guided above the second gear 70.

[0057] Therefore, with this configuration, oil can be directed to places inside the casing 12 that are difficult for oil to reach when circulating due to the operation of the power transmission mechanism 50, thereby preventing insufficient lubrication of the gears and rotating shafts arranged inside the casing 12.

[0058] (2) The fourth gear 76 is a helical gear.

[0059] This configuration reduces uneven oil scattering when helical gears, which are stronger, smoother, and quieter than spur gears, are used, and makes it possible to guide oil to places inside the casing 12 that are difficult for oil to reach. Therefore, it is possible to prevent insufficient lubrication of the gears and rotating shafts arranged inside the casing 12.

[0060] (3) When the first gear 60 rotates in the forward direction, the first gear 60 and the second gear 70 are arranged to mesh with each other downstream in the forward rotation direction of the first gear 60, and when the first gear 60 rotates in the forward direction, the third gear 72 and the fourth gear 76 are arranged to mesh with each other upstream in the rotation direction of the third gear 72.

[0061] This configuration reduces uneven oil scattering, which becomes noticeable when the vehicle is rotating in the direction of travel, and allows oil to be guided to places inside the casing 12 that are difficult for oil to reach. Therefore, it is possible to prevent insufficient lubrication of the gears and rotating shafts arranged inside the casing 12.

[0062] (4) Equipped with a guide rib 113 that guides oil to the catch tank 100.

[0063] With this configuration, some of the oil that is scooped up by third gear 72 and splashed toward housing 20 bounces off guide rib 113, making it easier for the oil to be taken into opening 101 of catch tank 100. The oil taken into the catch tank is guided by oil path 133 from the fourth gear 76 side to above second gear 70, so that oil can be guided to places inside casing 12 that are difficult for oil to reach. This prevents the gears and rotating shafts arranged inside casing 12 from becoming insufficiently lubricated.

[0064] [Other Embodiments] The present embodiment has been described above, but the above embodiment merely shows one application example of the present invention, and is not intended to limit the technical scope of the present invention to the specific configuration of the above embodiment.

[0065] The shape of the catch tank 100, the shape of the opening 101 formed in the catch tank 100, and the shapes of the oil inlet 131, oil outlet 132 and oil path 133 that constitute the supply section 130 are not limited to the shapes shown in FIG. 6.

[0066] In this embodiment, it has been described that the casing 12 is provided with a catch tank 100 for storing oil above the second gear 70, with an oil inlet 131 formed on the fourth gear 76 side and an oil outlet 132 formed above the second gear 70. The supply unit 130 may have any structure as long as it can guide oil to the second gear 70, and the positions of the opening 101 serving as an oil inlet of the catch tank 100, and the oil inlet 131, oil outlet 132, and oil path 133 in the supply unit 130 are not limited to those shown in Figures 3, 4, and 6.

[0067] REFERENCE SIGNS LIST 10 Drive unit 12 Casing 20 Housing 24 Case 30 Mechanism accommodating section 50 Power transmission mechanism 52 Input shaft 54 ​​Gear 58 Output shaft 60 First gear 70 Second gear 72 Third gear 76 Fourth gear 100 Catch tank 113 Guide rib 130 Supply section 131 Oil inlet 132 Oil outlet 133 Oil path

Claims

1. A drive device comprising: a motor as a drive source; a power transmission mechanism that transmits the power of the motor to drive wheels; and a casing that houses the motor and the power transmission mechanism, wherein the power transmission mechanism comprises: an input shaft to which power is input from the motor; an output shaft that transmits the power from the motor input via gears to the drive wheels; and an intermediate shaft provided between the input shaft and the output shaft, wherein, as viewed in the axial direction of the power transmission mechanism, the intermediate shaft is located vertically higher than the input shaft and the output shaft; a first gear provided on the input shaft; a second gear provided on the intermediate shaft and meshing with the first gear; a third gear arranged alongside the second gear in the axial direction of the intermediate shaft; and a fourth gear provided on the output shaft and meshing with the third gear, wherein the casing comprises a catch tank above the second gear that stores oil, and the catch tank has a supply section that supplies the stored oil to the second gear, the supply section has an oil inlet formed on a side of the fourth gear as viewed in the axial direction of the power transmission mechanism, and an oil outlet formed above the second gear.

2. A drive device according to claim 1, wherein at least the fourth gear is a helical gear.

3. A drive device according to claim 1 or 2, wherein the first gear and the second gear are arranged to mesh together downstream in the direction of forward rotation of the first gear when the first gear is rotating in the forward direction, and the third gear and the fourth gear are arranged to mesh together upstream in the direction of rotation of the third gear when the first gear is rotating in the forward direction.

4. A drive device according to claim 1, further comprising a guide rib for guiding the oil to the catch tank.

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