Drive device

Abstract

[Problem] To provide a drive device capable of suppressing oil leakage. [Solution] A power transmission mechanism comprises: an input shaft to which power is input from a motor; a gear provided on the input shaft; and an output shaft for transmitting the power input via the gear from the motor to a drive wheel. A casing is formed with a gear placement region in which the gear is disposed, and a breather chamber which is disposed above the gear and has a passage communicating with the outside and an opening portion communicating with the gear placement region. The casing is formed with: an inflow space that is disposed adjacent to the breather chamber and that allows the inflow of oil splashed up by the gear; and a rib that extends along the outer edge of the gear and has a tip-end portion located below the opening portion between the opening portion and the gear. The casing is formed with a gap provided opposite the tip-end portion and allowing the oil to flow between the gear placement region and the inflow space. The tip-end portion is formed with a bend portion that bends into the inflow space as the bend portion extends toward the tip end.

Description

Drive unit

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

[0002] Patent Document 1 discloses a motor case having a motor chamber for accommodating an electric motor and a gear chamber for accommodating a gear. A breather mechanism is provided above the gear chamber.

[0003] JP 2010-190299 A

[0004] When providing a breather chamber in the gear chamber of such a device, depending on the layout, it may be necessary to locate the breather chamber above the input shaft, which rotates at a high speed. In this case, a large amount of oil may enter the breather chamber from the breather path, and the oil may leak to the outside.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a drive device that can suppress oil leakage.

[0006] According to one aspect of the present invention, there is provided a drive unit 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, a gear provided on the input shaft, and an output shaft that transmits the power from the motor input via the gear to the drive wheels, and the casing comprises a gear arrangement area in which the gear is arranged, a passage that is arranged above the gear and communicates with the outside, and A drive device is provided which includes: a breather chamber having an opening communicating with a gear arrangement area; an inflow space arranged adjacent to the breather chamber and allowing the inflow of oil scooped up by the gear; a rib extending along the outer edge of the gear and having a tip located below the opening between the opening and the gear; and a gap facing the tip, allowing the flow of oil between the gear arrangement area and the inflow space, wherein the tip is formed with a bent portion that bends toward the tip and into the inflow space.

[0007] According to one aspect of the present invention, a tip of a rib extending along the outer edge of the gear is disposed below the opening of the breather chamber communicating with the gear arrangement area, and the tip has a bent portion that bends toward the inflow space as it approaches the tip, so that the tip of the rib prevents oil scooped up by the gear from directly entering the opening.

[0008] Furthermore, the gap provided facing the tip of the rib narrows toward the inside of the inflow space due to the bent portion formed at the tip, increasing the flow rate of oil passing through the gap. This creates a pressure difference between the breather chamber and the inflow space, and the pressure difference between the breather chamber and the inflow space promotes the discharge of oil that has entered the breather chamber from the breather chamber, contributing to a reduction in the amount of oil in the breather chamber.

[0009] Therefore, compared to when oil is scooped up toward the opening by the rotating gear and the oil in the breather chamber increases, it is possible to suppress oil leakage to the outside from the passage connected to the breather chamber.

[0010] 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 state in which the case has been removed from the housing of the drive unit. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 1. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 1. FIG. 7 is a perspective view of the gap portion in FIG. 6 as seen from the housing side. FIG. 8 is a perspective view showing the joint portion between the housing and the case, showing the opening of the reserve chamber. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 5.

[0011] A driving device 10 according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

[0012] 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 state in which the case 24 is removed from the housing 20 of the drive unit 10. Note that the upward direction U, downward direction D, front direction FR, rear direction RR, left direction L, and right direction R shown in the figures indicate directions when the drive unit is mounted on a vehicle. The left direction L and right direction R of the vehicle refer to 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 an upper portion 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] (Input Shaft) More specifically, 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] (First Gear and Second Gear) The gear 54 provided on the input shaft 52 is composed of a first gear 60 and a second gear 62 that rotate together with the input shaft 52. The first gear 60 and the second gear 62 are arranged side by side in the axial direction of the input shaft 52. The second gear 62 has a larger diameter than the first gear 60.

[0023] The first gear 60 is disposed in the case recess 42 (see FIG. 9). The second gear 62 is disposed closer to the housing than the first gear 60, with a portion of the second gear 62 disposed in the case recess 42 and another portion of the second gear 62 disposed in the housing recess 32 (see FIG. 9).

[0024] The first gear 60 transmits the rotation of the input shaft 52 to the intermediate shaft 56. The second gear 62 constitutes a parking gear. A plurality of engagement recesses 62B are formed at equal intervals on the circumferential surface of the second gear 62. An engagement claw 64B of a lock plate 64 journaled on a shaft portion 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] (Third Gear and Fourth Gear) The intermediate shaft 56 is provided with a third gear 70 and a fourth gear (not shown because it is positioned closer to the housing recess wall surface 32B than the third gear 70) that rotate together with the intermediate shaft 56. The third gear 70 and the fourth gear (not shown) are arranged side by side in the axial direction of the intermediate shaft 56. The third gear 70 is arranged on the case 24 side, and the fourth gear is arranged on the housing 20 side.

[0026] The third gear 70 meshes with the first gear 60 provided on the input shaft 52. The third 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 fourth gear (not shown) has a smaller diameter than the third gear 70. The fourth gear transmits the rotation of the intermediate shaft 56 to the output shaft 58.

[0027] (Fifth Gear) The output shaft 58 is provided with a fifth gear 76 that rotates together with the output shaft 58. The fifth gear 76 constitutes a ring gear of the differential gear.

[0028] The fifth gear 76 meshes with the fourth gear (not shown). The fifth gear 76 has a larger diameter than the fourth gear, and transmits the rotation of the intermediate shaft 56 to the output shaft 58 after reducing the rotation speed.

[0029] (Mechanism Housing Section) The mechanism housing section 30 of the casing 12 is formed with a gear arrangement area 80 in which the first gear 60, the second gear 62, the third gear 70, the fourth gear, and the fifth gear 76 are arranged.

[0030] A breather chamber 82 is formed in the mechanism housing portion 30 of the casing 12, and is disposed above the gear 54 consisting of the first gear 60 and the second gear 62. The breather chamber 82 has a passage communicating with the outside of the casing 12 and an opening 140 (see FIGS. 6 to 8 ) communicating with the gear arrangement area 80. The breather chamber 82 allows gas to flow between the gear arrangement area 80 and the outside of the casing 12, and constitutes a chamber for adjusting the pressure inside the mechanism housing portion 30 of the casing 12.

[0031] The mechanism housing section 30 of the casing 12 is provided with an inflow space 84 located adjacent to the breather chamber 82 to allow the inflow of oil scooped up by the gear 54 consisting of the first gear 60 and the second gear 62.

[0032] In addition, a rib 88 is formed in the mechanism accommodating section 30 of the casing 12, extending along the outer edge of the gear 54 and having a tip 86 positioned below D of the opening 140 (see Figures 6 to 8) between the opening 140 and the gear 54.

[0033] Furthermore, a gap 90 is formed in the mechanism accommodating portion 30 of the casing 12 facing the tip end 86 of the rib 88 to allow oil to flow between the gear arrangement area 80 and the inflow space 84 .

[0034] A bent portion 86B (see FIG. 5) is formed at the tip 86 of the rib 88, bending toward the inflow space 84 as it approaches the tip. In addition, a protruding portion 86C is formed at the tip 86 of the rib 88. The protruding portion 86C is arranged on the outer periphery of the second gear 62 and aligned with the bent portion 86B in the axial direction of the input shaft 52, protruding in the circumferential direction CD of the rib 88 (see FIG. 6) and having a length in the protruding direction that is shorter than that of the bent portion 86B.

[0035] Next, the mechanism accommodating portion 30 of the casing 12 will be described with reference to FIGS. 5 to 9. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 1. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 1. FIG. 7 is a perspective view of the gap 90 in FIG. 6 as seen from the housing 20 side. FIG. 8 is a perspective view showing the joint between the housing 20 and the case 24, showing the opening 140 of the breather chamber 82. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 5.

[0036] (Gear placement area) As shown in Figures 5 and 6, the gear placement area 80 is formed in the mechanism housing section 30 of the casing 12, and the mechanism housing section 30 partially forms the breather chamber 82 and inflow space 84 described above (see Figure 4).

[0037] (Breather Chamber) The breather chamber 82 is disposed above the first gear 60 and the second gear 62. The breather chamber 82 is formed by the housing recess wall surface 32B (see FIG. 6), a housing surrounding rib 100 formed on the housing recess wall surface 32B, the case recess wall surface 42B (see FIG. 5), and a case surrounding rib 102 formed on the case recess wall surface 42B.

[0038] 5 , the case surrounding rib 102 has a part of the case recess peripheral wall 44 that surrounds the case recess 42, and a case arc rib 110 that extends along the first gear 60 above the first gear 60. The case surrounding rib 102 has a case rear rib 112 that connects the edge of the case arc rib 110 on the vehicle rear RR side to the case recess peripheral wall 44.

[0039] The case surrounding rib 102 also has a case inclined rib 114 that extends downward D from the case recess peripheral wall 44 and is inclined toward the front (FR) of the vehicle as it extends downward D. The case surrounding rib 102 has a case front rib 116 on the front (FR) side of the vehicle that connects the case inclined rib 114 to the case arc rib 110.

[0040] A case partitioning rib 118 is formed between the case recess peripheral wall 44 and the case arc rib 110. As a result, the breather chamber 82 is partitioned by the case partitioning rib 118 into a small chamber 120 on the front FR side of the vehicle and a large chamber 122 on the front FR side of the vehicle.

[0041] (Breather chamber: housing side) As shown in Figure 6, the housing surrounding rib 100 has a portion of the housing recess peripheral wall 34 that surrounds the housing recess 32, and a housing arc rib 130 that extends along the second gear 62 above U of the second gear 62.

[0042] The housing surrounding rib 100 also has a housing rear rib 132 that connects the edge of the housing arc rib 130 on the vehicle rearward (RR) side to the housing recess peripheral wall 34. The housing surrounding rib 100 also has a housing inclined rib 134 that extends downward (D) from the housing recess peripheral wall 34 and is inclined toward the vehicle front (FR) as it extends downward (D).

[0043] The housing surrounding rib 100 also has a housing front rib 136 on the vehicle front (FR) side that connects the housing inclined rib 134 to the housing arc rib 130 .

[0044] A housing dividing rib 128 is formed between the housing recess peripheral wall 34 and the housing arc rib 130. As a result, the breather chamber 82 is divided by the housing dividing rib 128 into a small chamber 120 on the vehicle front (FR) side and a large chamber 122 on the vehicle rear (RR) side.

[0045] Between the housing inclined rib 134 that forms the small chamber 120 and the housing arc rib 130, a protrusion 138 is formed, the protrusion amount from the housing recess wall surface 32B being smaller than that of the housing inclined rib 134 and the housing arc rib 130.

[0046] 5 and 6, with the case 24 attached to the housing 20, the end faces of the housing recess peripheral wall 34 and the case recess peripheral wall 44 abut against each other, and the end faces of the housing arc rib 130 and the case arc rib 110 abut against each other. Furthermore, the end faces of the housing rear rib 132 and the case rear rib 112 abut against each other, and the end faces of the housing inclined rib 134 and the case inclined rib 114 abut against each other.

[0047] 6 to 8, the housing front rib 136 is positioned diagonally downward and toward the front (FR) side of the vehicle relative to the case front rib 116. As a result, an opening 140 is formed between the housing front rib 136 and the case front rib 116, which connects the small chamber 120 on the housing 20 side of the breather chamber 82 with the gear arrangement area 80. The opening 140 opens toward the case 24, which is positioned to the left (L) of the vehicle (see FIG. 8).

[0048] The housing partitioning rib 128 and the case partitioning rib 118 are positioned at positions offset in the fore-and-aft direction of the vehicle, thereby forming a gap (not shown) between the housing partitioning rib 128 and the case partitioning rib 118 that connects the small chamber 120 on the housing 20 side with the large chamber 122 on the case 24 side.

[0049] A vent hole (not shown) connected to a vent pipe 148 (see FIGS. 4 and 6) protruding from the housing 20 is opened in the large chamber 122 of the breather chamber 82. As a result, a passage communicating with the outside of the casing 12 is formed in the breather chamber 82 by the vent hole (not shown) and the vent pipe 148.

[0050] The flow rate of oil flowing from the gear arrangement area 80 into the small chamber 120 of the breather chamber 82 through the opening 140 is reduced by the ribs 138 that protrude into the small chamber 120. Furthermore, air that enters the small chamber 120 of the breather chamber 82 through the opening 140 enters the large chamber 122 through the gap between the housing partition rib 128 and the case partition rib 118. The air that enters the large chamber 122 is discharged to the outside of the casing 12 through a vent hole (not shown) and a vent pipe 148.

[0051] (Inflow space) The inflow space 84 located on the front (FR) side of the breather chamber 82 is formed by the housing recess wall surface 32B, a rib (described later) formed on the housing recess wall surface 32B, the case recess wall surface 42B, and a rib (described later) formed on the case recess wall surface 42B.

[0052] As shown in Figure 5, the rib on the case recess wall surface 42B that forms the inflow space 84 includes a case connecting rib 150 that extends diagonally upward U from the case inclined rib 114 toward the front FR of the vehicle and is connected to the case recess peripheral wall 44, and a portion of the case recess peripheral wall 44.

[0053] The ribs on the case recess wall surface 42B that form the inflow space 84 include a case vertical rib 152 that extends up and down on the vehicle front FR side of the first gear 60. The ribs on the case recess wall surface 42B include a case lower rib 156 that extends from the lower end of the case vertical rib 152 toward the vehicle front FR, then bypasses the case circular rib 154, extends downward D, and is connected to the case recess peripheral wall 44.

[0054] A case extending rib 158 extending toward the back side of the inflow space 84 is formed on the upper edge of the case vertical rib 152 .

[0055] Although details are omitted (see FIG. 6 ), a housing connecting rib 160 is formed on the housing recess wall surface 32B, which abuts against the case connecting rib 150. A portion of the housing recess peripheral wall 34 is formed on the housing recess wall surface 32B, which abuts against a portion of the case recess peripheral wall 44 that forms the inflow space 84.

[0056] Further, the housing recess wall surface 32B is formed with a housing vertical rib 162 that abuts against the case vertical rib 152, and a housing lower rib 166 that abuts against the case lower rib 156. The housing recess wall surface 32B is formed with a housing extension rib 168 that abuts against the case extension rib 158.

[0057] (Catch Tank) A catch tank 170 capable of storing oil that has flowed into the inflow space 84 is provided inside the inflow space 84 .

[0058] The catch tank 170 is formed by the housing recess wall surface 32B, a rib (described later) formed on the housing recess wall surface 32B, the case recess wall surface 42B, and a rib (described later) formed on the case recess wall surface 42B.

[0059] As shown in Figure 5, the ribs on the case recess wall surface 42B that form the catch tank 170 include the previously described case vertical rib 152, a portion of the previously described case lower rib 156, and a case side wall rib 180 that forms the side wall 174 extending upward U from the case lower rib 156.

[0060] 6, the rib on the housing recess wall surface 32B that forms the catch tank 170 includes the aforementioned housing vertical rib 162 and a part of the aforementioned housing lower rib 166. The rib on the housing recess wall surface 32B includes a housing side wall rib 190 that forms a side wall 174 that extends upward U from the housing lower rib 166.

[0061] The end faces of the case vertical ribs 152 abut against the end faces of the housing vertical ribs 162, and the end faces of the case lower ribs 156 abut against the end faces of the housing lower ribs 166. The end faces of the case side wall ribs 180 abut against the end faces of the housing side wall ribs 190, and the catch tank 170 is formed in the shape of a container that opens upward U.

[0062] The case sidewall ribs 180 and the housing sidewall ribs 190 that form the sidewalls 174 of the catch tank 170 have their upper ends inclined toward the rear (RR) of the vehicle. As a result, the ends of the sidewalls 174 of the catch tank 170 that are disposed away from the gap 90 are inclined toward the gap 90.

[0063] (Rib) As shown in FIGS. 5 and 6, the rib 88, whose tip 86 is located between the opening 140 of the breather chamber 82 and the gear 54, is composed of a case arc rib 110 and a housing arc rib 130 that are abutted against each other.

[0064] 5, 7, and 8, the tip 86 of the case arc rib 110 formed on the case recess wall surface 42B that constitutes the rib 88 has a bent portion 86B that bends toward the tip and into the inflow space 84. As a result, the tip 86 of the rib 88 has the bent portion 86B on the case 24 side that bends toward the tip and into the inflow space 84.

[0065] 5 to 8 , the bent portion 86B is formed in the case arc rib 110 on the case 24 side where the first gear 60 is disposed. As a result, the bent portion 86B is disposed between the opening 140 of the breather chamber 82 and the first gear 60.

[0066] The opening 140 of the breather chamber 82 opens toward the case 24 (see FIG. 8). The bent portion 86B formed in the case arc rib 110 of the case recess wall surface 42B has a height that reaches from the case recess wall surface 42B to the housing 20. As a result, the bent portion 86B provided below D of the opening 140 extends along the opening direction OD of the opening 140 (see FIG. 8).

[0067] 6 to 8 , the protruding portion 86C is formed at the tip of the housing arc rib 130 on the housing 20 side where the second gear 62 is disposed. As a result, the protruding portion 86C and the bent portion 86B are arranged side by side in the axial direction of the input shaft 52. In addition, the protruding portion 86C is arranged on the outer periphery of the second gear 62.

[0068] The protruding portion 86C protrudes in the circumferential direction CD of the housing arc rib 130, and its length in the protruding direction is shorter than that of the bent portion 86B. As a result, the oil scooped up in large quantities by the second gear 62, which has a larger diameter than the first gear 60, mainly passes through the tip side of the protruding portion 86C rather than the tip side of the bent portion 86B.

[0069] 7 , the protruding portion 86C protruding in the circumferential direction CD of the housing arc rib 130 has a function of directing the oil scooped up by the second gear 62 to a first flow path 200 between the second gear 62 and the rib 88. The protruding portion 86C also has a function of directing the oil scooped up by the second gear 62 to a second flow path 202 that passes through the gap 90 and leads to the inflow space 84.

[0070] This promotes the flow of oil into the inflow space 84 compared to when the oil scooped up by the second gear 62 stagnates at the tip of the housing arc rib 130, as occurs when there is no protrusion 86C at the tip of the housing arc rib 130.

[0071] (Gap) As shown in FIGS. 5 to 7 , the gap 90 is formed at the tip of the rib 88 that is composed of the case arc rib 110 and the housing arc rib 130 .

[0072] The tip of the case arc rib 110 is spaced apart from the case longitudinal rib 152 that forms the inflow space 84. As shown in Figures 6 and 7, the tip of the housing arc rib 130 is spaced apart from the housing longitudinal rib 162 that forms the inflow space 84.

[0073] As a result, a gap 90 that connects the gear arrangement area 80 and the inflow space 84 is formed at the tip of the rib 88, which is made up of the case arc rib 110 and the housing arc rib 130. The oil scooped up by the gear 54 is allowed to flow into the inflow space 84 through the gap 90. Furthermore, the oil that has flowed into the inflow space 84 is allowed to flow out into the gear arrangement area 80 through the gap 90.

[0074] The gap 90 narrows as it moves deeper into the inflow space 84 due to the bent portion 86B formed in the rib 88. As a result, the flow rate of oil flowing from the gap 90 into the inflow space 84 increases as it moves deeper into the inflow space 84. As a result, the pressure around the opening 140, which is located deeper into the inflow space 84 than the bent portion 86B, becomes lower than the pressure inside the breather chamber 82, and a pressure difference occurs between the breather chamber 82 and the vicinity of the entrance of the opening 140. As a result, for example, oil that has flowed into the breather chamber 82 is promoted to be discharged from the opening 140.

[0075] (Explanation of Oil Flow in Inflow Space) The flow of oil scooped up by the second gear 62 will be described with reference to the drawings.

[0076] 5 to 9, some of the oil scooped up at the portion of the second gear 62 on the housing 20 side (see FIG. 9) flows into the inflow space 84 (see FIG. 6) through the tip of the protruding portion 86C of the housing arc rib 130 and the gap 90. Some of the oil that flows into the inflow space 84 is forced to flow toward the catch tank 170 by the housing connecting rib 160 (see FIG. 6).

[0077] Furthermore, some of the oil scooped up at the portion of the second gear 62 on the case 24 side (see FIG. 9 ) is prevented from flowing toward the opening 140 by the bent portion 86B of the case arc rib 110. The oil whose flow is not prevented by the bent portion 86B flows into the inflow space 84 through the tip of the bent portion 86B of the case arc rib 110 and the gap 90 (see FIG. 5 ). As described above, the oil passing through the tip of the bent portion 86B generates a pressure difference between the breather chamber 82 and the vicinity of the entrance to the opening 140.

[0078] A portion of the oil that has flowed into the inflow space 84 is diverted by the case connecting rib 150 toward the catch tank 170 (see FIG. 5).

[0079] 6, part of the oil that has flowed toward the catch tank 170 flows into the catch tank 170. In addition, part of the oil that has flowed toward the catch tank 170 has its flow velocity reduced when it hits the tip of the side wall 174 of the catch tank 170, and then flows toward the gap 90.

[0080] In this way, the oil that has flowed into the inflow space 84 and has nowhere to go flows out into the gear arrangement area 80 through the gap 90 and is supplied to the first gear 60.

[0081] At this time, some of the oil flowing out from the gap 90 to the gear arrangement area 80 flows near the opening 140 that opens above the first gear 60. This flow of oil promotes the discharge of oil that has entered the breather chamber 82 from the opening 140.

[0082] (Functions and Effects) The main functions and effects of the drive device 10 configured as above will be summarized below.

[0083] (1) The drive unit 10 includes a motor (not shown) that serves as a drive source, a power transmission mechanism 50 that transmits power from the motor to drive wheels (not shown), 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, 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. The casing 12 is formed with a gear arrangement region 80 in which the gear 54 is arranged, and a breather chamber 82 that is arranged above the gear 54 and has a passage (148) that communicates with the outside and an opening 140 that communicates with the gear arrangement region 80. The casing 12 is formed with an inflow space 84 that is arranged adjacent to the breather chamber 82 and that allows the inflow of oil scooped up by the gear 54. The casing 12 is formed with a rib 88 that extends along the outer edge of the gear 54 and has a tip portion 86 located at D below the opening 140 between the opening 140 and the gear 54. The casing 12 is provided with a gap 90 facing the tip portion 86, which allows oil to flow between the gear arrangement region 80 and the inflow space 84. The tip portion 86 is formed with a bent portion 86B that bends toward the inside of the inflow space 84 as it approaches the tip.

[0084] According to this embodiment, the tip 86 of the rib 88 extending along the outer edge of the gear 54 is disposed below D the opening 140 of the breather chamber 82 that communicates with the gear arrangement area 80. The tip 86 is formed with a bent portion 86B that bends toward the inflow space 84 as it approaches the tip. Therefore, the tip 86 of the rib 88 prevents the oil scooped up by the gear 54 from directly entering the opening 140.

[0085] Furthermore, the gap 90 provided facing the tip 86 of the rib 88 narrows toward the inside of the inflow space 84 due to the bent portion 86B formed at the tip 86, and the flow rate of oil flowing through the gap 90 increases. This causes a pressure difference between the breather chamber 82 and the inflow space 84. Therefore, the pressure difference between the breather chamber 82 and the inflow space 84 promotes the discharge of oil that has entered the breather chamber 82 from the breather chamber 82, which can contribute to reducing the amount of oil in the breather chamber 82.

[0086] Therefore, compared to when oil is scraped up toward the opening 140 by the rotating gear 54, oil flows from the opening 140 into the breather chamber 82, and the amount of oil in the breather chamber 82 increases, it is possible to suppress oil leakage from the passage connected to the breather chamber 82 to the outside of the casing 12.

[0087] Furthermore, in the drive unit 10 of this embodiment, the power transmission mechanism 50 constitutes a reducer, and the input shaft 52 rotates at a higher speed than the intermediate shaft 56 and the output shaft 58. As a result, the oil scooped up by the gear 54 of the input shaft 52 is scooped up at a higher speed than the oil scooped up by the fifth gear 76 of the output shaft 58. This further increases the pressure difference generated between the breather chamber 82 and the inflow space 84, and the oil that has entered the breather chamber 82 is further expelled from the breather chamber 82, which can contribute to a reduction in the oil in the breather chamber 82.

[0088] In this way, even in this embodiment in which the oil is scooped up at high speed, it is possible to suppress oil leakage to the outside of the casing 12.

[0089] Furthermore, a bent portion 86B is disposed below D of the opening 140 of the breather chamber 82. Therefore, even if oil flows from the gear 54 side toward the opening 140 due to pulsation, it is possible to suppress oil from entering through the opening 140.

[0090] (2) The bent portion 86B provided below the opening 140 D extends along the opening direction OD of the opening 140 .

[0091] In this embodiment, the bent portion 86B extends along the opening direction OD of the opening 140, and therefore, it is possible to effectively suppress the infiltration of oil from the opening 140 compared to when the bent portion 86B extends in a direction intersecting the opening direction OD.

[0092] (3) The catch tank 170 capable of storing oil that has flowed into the inflow space 84 is provided inside the inflow space 84 .

[0093] The drive unit 10 of this embodiment can store a portion of the oil that flows into the inflow space 84 in the catch tank 170. Therefore, compared to a case in which the oil that flows into the inflow space 84 is allowed to flow out through the gap 90 without being stored, the amount of oil that flows out through the vicinity of the opening 140 can be reduced. This makes it possible to suppress a decrease in the flow rate of the oil flowing in through the gap 90 and to suppress a decrease in the pressure difference that occurs between the breather chamber 82 and the inflow space 84. Therefore, it is possible to suppress the inflow of oil through the opening 140.

[0094] (4) The side wall 174 of the catch tank 170 arranged in a direction away from the gap 90 has a tip that is inclined toward the gap 90.

[0095] According to this embodiment, the flow rate of the oil that flows from the gap 90 into the inflow space 84 is reduced by the tip of the side wall 174 that is inclined toward the gap 90. This allows the drive unit 10 to reduce the flow rate of the oil that passes near the opening 140 and flows out, thereby further suppressing the inflow of oil from the opening 140.

[0096] (5) The gear 54 is composed of a first gear 60 arranged side by side so as to rotate together with the input shaft 52, and a second gear 62 having a larger diameter than the first gear 60, and the bent portion 86B is arranged between the opening 140 and the first gear 60.

[0097] In this embodiment, the bent portion 86B is disposed between the opening 140 and the first gear 60, and therefore, it is possible to efficiently prevent the oil that has been scooped up from entering through the opening 140.

[0098] Furthermore, the first gear 60 has a smaller diameter than the second gear 62, and the amount of oil scooped up by the first gear 60 is less than that by the second gear 62. Therefore, the oil that has been scooped up by the second gear 62 and flowed into the inflow space 84 can be made to flow out from the first gear 60 side and supplied to the first gear 60.

[0099] (6) The tip portion 86 is provided with a protruding portion 86C that is arranged on the outer periphery of the second gear 62 and aligned with the bent portion 86B in the axial direction of the input shaft 52, protruding in the circumferential direction CD of the rib 88 and having a length in the protruding direction that is shorter than that of the bent portion 86B.

[0100] In the present embodiment, a protrusion 86C that protrudes in the circumferential direction CD of the rib 88 is disposed on the outer periphery of the second gear 62 at the tip 86 of the rib 88. As a result, the flow of oil that is scooped up along the gear 54 is divided at the tip 86 of the rib 88 into a first flow path 200 that flows along the outer periphery of the gear 54 and a second flow path 202 that flows into the inflow space 84 via the gap 90.

[0101] Therefore, it is possible to promote the flow of oil into the inflow space 84 compared to when the tip 86 of the rib 88 does not have a protrusion 86C and the oil scooped up by the gear 54 stagnates at the tip of the rib 88.

[0102] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0103] REFERENCE SIGNS 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 62 Second gear 80 Gear arrangement area 82 Breather chamber 84 Inflow space 86 Tip portion 86B Bent portion 86C Protrusion 88 Rib 90 Gap 140 Opening 148 Ventilation pipe 170 Catch tank 174 Side wall CD Circumferential direction D Downward OD Opening direction U Upward

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; a gear provided on the input shaft; and an output shaft that transmits the power from the motor input via the gear to the drive wheels, wherein the casing is formed with: a gear arrangement area in which the gear is arranged; a breather chamber that is arranged above the gear and has a passage that communicates with the outside and an opening that communicates with the gear arrangement area; an inflow space that is arranged adjacent to the breather chamber and allows the inflow of oil scooped up by the gear; a rib that extends along the outer edge of the gear and has a tip located below the opening between the opening and the gear; and a gap that is provided facing the tip and allows oil to flow between the gear arrangement area and the inflow space. The drive device, wherein the tip end portion has a bent portion that bends toward the inflow space as it approaches the tip end.

2. A drive device according to claim 1, wherein the bent portion provided below the opening extends along the opening direction of the opening.

3. A drive device according to claim 1 or 2, wherein a catch tank capable of storing oil that has flowed into the inflow space is provided inside the inflow space.

4. A drive device according to claim 3, wherein the side wall of the catch tank arranged in a direction away from the gap has a tip that is inclined toward the gap.

5. A drive device according to claim 1, wherein the gear comprises a first gear arranged side by side so as to rotate together with the input shaft, and a second gear having a larger diameter than the first gear, and the bent portion is arranged between the opening and the first gear.

6. A drive device according to claim 5, wherein the tip end is provided with a protruding portion which is arranged on the outer periphery of the second gear in a state aligned with the bent portion in the axial direction of the input shaft, protruding in the circumferential direction of the rib and having a length in the protruding direction shorter than that of the bent portion.

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