Drive apparatus

Abstract

To provide a drive apparatus for a vehicle.SOLUTION: A drive apparatus includes: a casing that includes a motor chamber, a gear chamber and an electric unit chamber; a motor that is housed in the motor chamber and includes a motor shaft with a flow passage formed in the axial center of the motor shaft, the motor shaft having one end on the one axial-direction side positioned in the gear chamber; a gear unit that is housed in the gear chamber and mechanically connected to the one end of the motor shaft; an electric unit that is housed in the electric unit chamber and electrically connected to the motor; and a heat medium route that supplies a heat medium stored in the gear chamber to the flow passage of the motor shaft. At least a part of the electric unit chamber is positioned closer on the one axial-direction side than the one end of the motor shaft. The heat medium route is connected to the flow passage of the motor shaft at the one end of the motor shaft.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a drive device for a vehicle. [Background technology]

[0002] An integrated drive unit is known that includes a motor chamber, a gear chamber, and an electric unit chamber. Also known is a technology called axial cooling, in which a heat transfer medium flow path is formed at the axial center of the motor shaft. Related technology is disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-174478 Summary of the Invention [Problem to be solved by the invention]

[0004] In an integrated drive unit, there is a demand for a smaller size of the drive unit. However, in order to adopt axial cooling, a heat transfer medium path is required to supply a heat transfer medium to the axial center of the motor shaft. Depending on the routing of this heat transfer medium path, the size of the drive unit may increase due to the heat transfer medium path. [Means for solving the problem]

[0005] The present specification discloses a drive device for a vehicle that includes a casing including a motor chamber, a gear chamber, and an electric unit chamber. The drive device is housed in the motor chamber and includes a motor having a motor shaft with a flow path formed at its axis, with one axial end of the motor shaft located in the gear chamber. The drive device is housed in the gear chamber and includes a gear unit mechanically connected to one end of the motor shaft. The drive device is housed in the electric unit chamber and includes an electric unit electrically connected to the motor. The drive device includes a heat medium path that supplies a heat medium stored in the gear chamber to the flow path of the motor shaft. At least a portion of the electric unit chamber is located axially to one side of the one end of the motor shaft. The heat medium path is connected to the flow path of the motor shaft at one end of the motor shaft.

[0006] The heat medium can take various forms. For example, the heat medium may be oil, water, air, or the like. In the above configuration, the electric unit chamber can protrude axially to one side from one end of the motor shaft. The heat medium path is connected to one end of the motor shaft. This allows the axial width of the drive unit to be determined by the electric unit chamber rather than the heat medium path. Therefore, it is possible to prevent the axial width of the drive unit from being increased by the heat medium path. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a driving device 1. FIG. [Figure 2] FIG. 2 is a perspective view of the drive device 1. [Figure 3] FIG. 1 is a cross-sectional view showing a schematic configuration of a driving device 1001 of a comparative example. [Figure 4] FIG. 2 is a cross-sectional view showing a schematic configuration of a driving device 201. [Figure 5] FIG. 2 is a cross-sectional view showing a schematic configuration of a driving device 301. [Figure 6] FIG. 4 is a cross-sectional view showing a schematic configuration of a driving device 401. DETAILED DESCRIPTION OF THE INVENTION

[0008] At least a part of the electric unit chamber may be located on one axial side of the heat medium path.

[0009] According to the above configuration, it is possible to prevent the axial width of the drive device from being increased by the heat medium path.

[0010] At least a portion of the electric unit chamber may overlap with the gear chamber in a direction perpendicular to the axial direction.

[0011] According to the above-described configuration, the amount of protrusion of the electric unit chamber toward one side in the axial direction can be reduced, and the size of the drive device can be reduced.

[0012] At least a portion of the electric unit chamber may overlap the motor chamber in the axial direction.

[0013] According to the above-mentioned configuration, the amount of protrusion of the electric unit chamber in the direction perpendicular to the axial direction can be reduced, and the size of the drive device can be reduced.

[0014] At least a portion of the heat transfer medium path may be located on one axial side of the gear chamber.

[0015] A part of the electric unit chamber may be located on an extension of the motor shaft to one axial side. One end of the motor shaft may be supported by a partition wall between the gear chamber and the electric unit chamber. The heat medium path may pass through the electric unit chamber and penetrate the partition wall to be connected to the flow path.

[0016] According to the above configuration, the heat medium can be supplied from one end of the motor shaft.

[0017] The heat transfer medium path may extend from the outside of the casing, through a wall surface that defines the electric unit chamber of the casing, and into the electric unit chamber.

[0018] According to the above configuration, a heat transfer medium path can be formed that passes through the wall surface of the gear chamber and the inside of the electric unit chamber and reaches one end of the motor shaft.

[0019] The drive device may further include a pump that delivers the heat medium stored in the lower portion of the gear chamber to the heat medium path. The pump may be located on one axial side or the other axial side of the gear chamber.

[0020] The cooling fan may further include a heat medium cooler arranged on the heat medium path and configured to cool the heat medium. The heat medium cooler may be located on one axial side or the other axial side of the gear chamber.

[0021] The motor chamber and the gear chamber may be connected by a communication hole through which the heat medium can flow. The electric unit chamber may be isolated from the motor chamber and the gear chamber in a liquid-tight manner.

[0022] The casing may include a motor case having a motor chamber, a gear case defining at least a portion of the gear chamber, and an electric unit case defining at least a portion of the electric unit chamber. The gear case and the electric unit case may be fastened to the motor case by a plurality of fastening members.

[0023] According to the above configuration, the gear case and the electric unit case can be assembled independently of each other, which makes it easier to assemble the drive unit. [Example]

[0024] (Configuration of drive unit 1) FIG. 1 is a cross-sectional view showing the schematic configuration of a drive unit 1 of this embodiment. The drive unit 1 is an integrated device that houses a motor, a gear unit, and a power conversion unit for controlling the motor in the same casing. The directions FR, RH, and UP indicate the orientation of the drive unit 1 with respect to the vehicle (electric vehicle) when the drive unit 1 is mounted on the vehicle. The direction FR indicates the front in the longitudinal direction of the vehicle. The direction RH indicates the right in the lateral direction (or width direction) of the vehicle. The direction UP indicates the upward direction in the vertical direction of the vehicle. This is also true for other drawings. Note that in FIG. 1, multiple shafts (motor shaft 43, countershaft 52, drive shafts 57L and 57R) are shown expanded so that they are positioned on the same plane.

[0025] The drive device 1 is controlled by a control device 2. The control device 2 includes a CPU, RAM, ROM, an input / output interface, etc. The control device 2 is connected to a power conversion unit 21 and the like by signal lines (not shown).

[0026] The drive unit 1 includes a casing 10. The casing 10 includes a first case 11, a motor case 13, and a cover portion 15. The first case 11 and the motor case 13 may be cast metal.

[0027] The first case 11 has a first flange 11f extending along the outer periphery of the first case 11. The motor case 13 has a motor case flange 13f extending along the outer periphery of the motor case 13. The first case 11 is fastened to the motor case 13 with a plurality of bolts 60. The first case 11 also has an opening AP. A lid portion 15 is fastened to the first case 11 with a plurality of bolts 60 so as to close the opening AP.

[0028] The motor case 13 includes a motor chamber 31. The motor chamber 31 houses the motor 40. In other words, the motor case 13 houses the motor 40. The motor 40 includes a stator 41, a rotor 42, and a motor shaft 43. The stator 41 has a cylindrical shape. The rotor 42 is rotatably disposed inside the stator 41. The motor shaft 43 has a central axis CA.

[0029] The motor case 13 also has an opposing surface 13s that faces the first case 11. A motor shaft hole MH and a drive shaft hole DH1 are formed in the opposing surface 13s. The motor shaft 43 passes through the motor shaft hole MH. The left drive shaft 57L passes through the drive shaft hole DH1.

[0030] The first case 11 has a box shape with one open side. The first case 11 is fastened to the opposing surface 13s so that the open side is closed by the opposing surface 13s. This defines a gear chamber SP1 between the motor case 13 and the first case 11. The gear unit 50 is stored in the gear chamber SP1. In other words, the first case 11 houses the gear unit 50.

[0031] The gear unit 50 includes a shaft gear 51, a countershaft 52, a first counter gear 53, a second counter gear 54, a ring gear 55, and a differential gear 56. The shaft gear 51 is attached to the motor shaft 43, thereby mechanically connecting the gear unit 50 and the motor 40. The countershaft 52 is attached with the first counter gear 53 and the second counter gear 54. The first counter gear 53 meshes with the shaft gear 51. The second counter gear 54 meshes with the ring gear 55. The ring gear 55 is attached to the differential gear 56. A pair of drive shafts 57L and 57R extend from the differential gear 56 in the vehicle width direction. The drive shaft 57R passes through a drive shaft hole DH2 formed in the first case 11. A reservoir 58 is provided at the bottom of the gear chamber SP1. Oil 61 is stored in the reservoir 58. A part of the gear unit 50 is immersed in oil 61 stored in the storage portion 58 .

[0032] FIG. 2 shows a perspective view of the drive unit 1. FIG. 2 shows a state in which the cover 15 and the power conversion unit 21 have been removed. The position of one end 43e of the motor shaft 43 is indicated by a dotted line. As shown in FIGS. 1 and 2, the first case 11 is provided with an electric unit chamber SP2 having an opening AP. The opening AP can be sealed by fastening the cover 15 with bolts 60. In other words, the electric unit chamber SP2 is liquid-tightly isolated from the motor chamber 31 and the gear chamber SP1. The electric unit chamber SP2 houses the power conversion unit 21. The power conversion unit 21 is a component for controlling the power supplied to the motor 40 and the generated power. Examples of components included in the power conversion unit 21 include an inverter and a converter.

[0033] In the axial direction of the central axis CA of the motor shaft 43, the side on which the shaft gear 51 is arranged is defined as one axial side AD1. The opposite side is defined as the other axial side AD2. Furthermore, the direction perpendicular to the central axis CA is defined as the radial direction RD.

[0034] (Oil-cooled system and water-cooled system configuration) The drive unit 1 is equipped with an oil cooling system and a water cooling system. First, the oil cooling system will be described. The oil cooling system includes a strainer 71, an oil pump 72, an oil cooler 73, an oil passage 74, and an axial flow path 75. That is, in this embodiment, the first heat medium is oil, and the second heat medium is water.

[0035] The axial flow path 75 is a flow path formed on the axis of the hollow (cylindrical) motor shaft 43. The motor shaft 43 also has one end 43e on one axial side AD1. The one end 43e is located in the gear chamber SP1. An inlet to the axial flow path 75 is formed at the one end 43e. The one end 43e is supported by a bearing 59. The bearing 59 is fixed to the partition wall 11b between the gear chamber SP1 and the electric unit chamber SP2.

[0036] The oil passage 74 is a path for supplying oil to the motor 40. The oil passage 74 may have various structures. For example, it may be a pipe member or a tunnel formed in a wall surface. In this embodiment, at least a portion of the oil passage 74 is configured with a pipe member.

[0037] Oil passage 74 connects the discharge port of oil pump 72 to the inlet of oil cooler 73, and also connects the discharge port of oil cooler 73 to one end 43e of motor shaft 43. In other words, oil cooler 73 is disposed in a section of oil passage 74 that connects oil pump 72 to one end 43e of motor shaft 43. Oil passage 74 allows oil stored in gear chamber SP1 to be supplied to an axial flow path 75 of motor shaft 43.

[0038] The strainer 71 is disposed in the reservoir 58. The strainer 71 is connected to the intake port of an oil pump 72. The oil pump 72 is located on the other axial side AD2 of the gear chamber SP1. The oil pump 72 draws the oil 61 from the reservoir 58 through the strainer 71. The oil pump 72 then delivers the drawn oil to an oil cooler 73 through an oil passage 74.

[0039] The oil cooler 73 is a heat exchanger that cools oil by exchanging heat with cooling water. The oil cooler 73 is located on one axial side AD1 of the gear chamber SP1. That is, the oil cooler 73 and the oil pump 72 face each other across the gear chamber SP1. The oil cooler 73 overlaps with the gear chamber SP1 in the axial direction of the central axis CA. The oil cooler 73 also overlaps with the electric unit chamber SP2 in the radial direction RD. An oil passage 74 and a water passage 83 are arranged opposite each other within the oil cooler 73. In other words, the oil cooler 73 is provided on the oil passage 74 and the water passage 83. In this embodiment, the heat medium path corresponds to the oil passage 74.

[0040] An oil passage 74 connects the discharge port of the oil cooler 73 and one end 43e of the motor shaft 43. The oil passage 74, which connects the oil cooler 73 and the one end 43e, is located on one axial side AD1 of the gear chamber SP1. Specifically, a portion of the electric unit chamber SP2 is located on an extension of the motor shaft 43 to the one axial side AD1 (see area A1). The oil passage 74 extends from the outside of the casing 10, passes through a wall surface 11w that defines the electric unit chamber SP2, and into the electric unit chamber SP2 (see area A2). The oil passage 74 then passes through the electric unit chamber SP2 and penetrates the partition wall 11b (see area A3). An end of the oil passage 74 is connected to an axial flow path 75 at one end 43e of the motor shaft 43.

[0041] The axial flow passage 75 is provided with a plurality of discharge holes (not shown) that penetrate in the radial direction. The oil flows through the axial flow passage 75 toward the other axial side AD2. The oil is discharged from the discharge holes and the end of the axial flow passage 75 on the other axial side AD2, and is supplied to the rotor 42, stator 41, etc. The oil supplied to the motor 40 by the axial flow passage 75 flows downward within the motor chamber 31. The flowing oil returns to the reservoir 58 within the gear chamber SP1 via a communication hole 16 provided in the partition wall between the motor chamber 31 and the gear chamber SP1.

[0042] Next, the water-cooling system will be described. The water-cooling system includes a water pump 81, a radiator 82, and a water passage 83. The water passage 83 is a path that supplies cooling water to the power conversion unit 21. The water passage 83 is a path that circulates water from the water pump 81 via the radiator 82, the power conversion unit 21, and the oil cooler 73 to the water pump 81. The cooling water circulating through the water passage 83 can cool the power conversion unit 21 and also cool the oil in the oil cooler 73.

[0043] (effect) First, the problem will be explained using a comparative driving device 1001 shown in FIG. 3. The same reference numerals are used to designate common components between the comparative driving device 1001 and the driving device 1 (FIG. 1) of this embodiment. In the comparative driving device 1001, the motor shaft 43 has the other end 43e2 on the other axial side AD2. The other end 43e2 is provided with an inlet to the axial flow path 75. The oil passage 74 connects the discharge port of the oil cooler 73 to the other end 43e2 of the motor shaft 43. That is, in the driving device 1 (FIG. 1) of this embodiment, the oil passage 74 is located on the one axial side AD1 relative to the gear chamber SP1. On the other hand, in the comparative driving device 1001 (FIG. 3), the oil passage 74 is located on the other axial side AD2 relative to the motor chamber 31. Therefore, the oil passage 74 protrudes by a width W74 from the end face 13e of the motor case 13. Therefore, in the driving device 1001 of the comparative example, the width W1001 in the direction of the central axis CA is increased by the width W74 relative to the width W1 of the casing 10.

[0044] On the other hand, in the drive unit 1 of this embodiment (FIG. 1), a portion of the electric unit chamber SP2 is located on one axial side AD1 of the one end 43e of the motor shaft 43. That is, the electric unit chamber SP2 can be made to protrude on the one axial side AD1 of the one end 43e of the motor shaft 43. More specifically, the electric unit chamber SP2 can be positioned a distance DIS on the one axial side AD1 of the oil passage 74. The oil passage 74 is connected to the one end 43e of the motor shaft 43. This allows the oil passage 74 to be accommodated within the protruding range of the electric unit chamber SP2. In other words, the width W1 of the drive unit 1 in the direction of the central axis CA can be determined by the electric unit chamber SP2, not by the oil passage 74. Therefore, the width W1 of the drive unit 1 can be made equal to the width of the casing 10. It is possible to prevent the width W1 of the drive unit 1 from increasing due to the oil passage 74. It is possible to further reduce the size of the drive unit 1.

[0045] As shown in FIG. 1, a space is formed in the area opposite the gear unit 50 with respect to the motor shaft 43 due to the difference in dimensions between the motor 40 and the gear unit 50. A part of the electric unit chamber SP2 is disposed in this space. That is, in the radial direction RD perpendicular to the central axis CA, at least a part of the electric unit chamber SP2 overlaps with the gear chamber SP1. This allows for effective use of the space around the motor shaft 43. This reduces the amount of protrusion of the electric unit chamber SP2 on the one axial side AD1. This allows for a reduction in the size of the drive unit 1.

[0046] Furthermore, in the axial direction of the central axis CA, at least a portion of the electric unit chamber SP2 overlaps with the motor chamber 31. This also makes it possible to effectively utilize the space around the motor shaft 43. Therefore, the amount of protrusion of the electric unit chamber SP2 in the radial direction RD can be reduced. [Example]

[0047] The second embodiment differs from the first embodiment in the arrangement of the oil pump 72. The same reference numerals are used to designate parts common to the first and second embodiments, and descriptions thereof will be omitted.

[0048] FIG. 4 shows a schematic configuration of a drive unit 201 of a second embodiment. FIG. 4 is a cross-sectional view similar to FIG. 1. The oil pump 72 is located on one axial side AD1 of the gear chamber SP1. That is, both the oil pump 72 and the oil cooler 73 are located on the same side of the gear chamber SP1. The oil pump 72 and the oil cooler 73 overlap with the gear chamber SP1 in the axial direction of the central axis CA. The oil pump 72 and the oil cooler 73 also overlap with the electric unit chamber SP2 in the radial direction RD. An oil passage 74 connects the discharge port of the oil pump 72 to the inlet of the oil cooler 73 and also connects the discharge port of the oil cooler 73 to one end 43e of the motor shaft 43.

[0049] In the drive unit 201 of the second embodiment, the oil passage 74 can also be accommodated within the range in which the electric unit chamber SP2 protrudes. This makes it possible to prevent the width W1 of the drive unit 1 from being increased by the oil passage 74. [Example]

[0050] The third embodiment differs from the first embodiment in the arrangement of the oil cooler 73. The same reference numerals are used to designate parts common to the first and third embodiments, and descriptions thereof will be omitted.

[0051] FIG. 5 shows a schematic configuration of a drive unit 301 of a third embodiment. FIG. 5 is a cross-sectional view similar to FIG. 1. The oil cooler 73 is located on the other axial side AD2 of the gear chamber SP1. That is, both the oil pump 72 and the oil cooler 73 are arranged on the same side of the gear chamber SP1. The oil cooler 73 overlaps with the gear chamber SP1 in the axial direction of the central axis CA. An oil passage 74 connects the discharge port of the oil pump 72 to the inlet of the oil cooler 73 and also connects the discharge port of the oil cooler 73 to one end 43e of the motor shaft 43.

[0052] In the driving device 301 of the third embodiment as well, it is possible to prevent the width W1 of the driving device 1 from being increased by the oil passage 74. [Example]

[0053] The fourth embodiment differs from the first embodiment in the form of a casing. Components common to the first and fourth embodiments are given the same reference numerals and will not be described. FIG. 6 shows a schematic configuration of a drive unit 401 of the fourth embodiment. FIG. 6 is a cross-sectional view similar to FIG. 1. In FIG. 6, elements specific to the fourth embodiment are distinguished by being given reference numerals in the 400s.

[0054] The casing 410 includes a first case 411, a second case 412, and a motor case 13. The first case 411 is fastened to an opposing surface 13s of the motor case 13 by a plurality of bolts 60. A gear chamber SP1 is defined between the motor case 13 and the first case 411.

[0055] The second case 412 has a box shape with one open side. The second case 412 is fastened to the opposing surface 13s and the upper surface 411u of the first case 411 with a plurality of bolts 60. This defines an electric unit chamber SP2 between the motor case 13 and the first case 411 and the second case 412. Therefore, by assembling the second case 412 onto the first case 411, a part of the electric unit chamber SP2 can be positioned on an extension line of one axial side AD1 of the motor shaft 43 (see area A1).

[0056] (effect) By configuring the first case 411 that houses the gear unit 50 and the second case 412 that houses the power conversion unit 21 as separate bodies, it is possible to attach the power conversion unit 21 with only the second case 412 removed from the motor case 13. This prevents interference from the second case 412 when attaching the power conversion unit 21. This increases the access direction of a tool to the contact portion between the power conversion unit 21 and the opposing surface 13s (see dotted arrow Y1). This improves the ease of assembly of the power conversion unit 21.

[0057] Although the embodiments have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings simultaneously achieves multiple objectives, and achieving one of these objectives itself has technical utility.

[0058] (Variation) The vehicle on which the drive device of this specification is installed is not limited to an electric vehicle. The drive device of this specification can be installed, for example, in a hybrid vehicle or a plug-in hybrid vehicle. In this case, the drive device of this specification may house multiple motors or a planetary gear mechanism in a casing. The drive device of this specification can also be applied to vehicles that use an electric motor for at least part of their driving, such as a fuel cell vehicle. [Explanation of symbols]

[0059] 1: Drive unit 10: Casing 21: Power conversion unit 40: Motor 43: Motor shaft 43e: One end 50: Gear unit 61: Oil 73: Oil cooler 74: Oil passage 75: Axial flow passage 83: Water passage AD1: One side in the axial direction SP1: Gear chamber SP2: Electric unit chamber

Claims

1. A drive device for a vehicle, comprising: a casing including a motor chamber, a gear chamber, and an electric unit chamber; a motor housed in the motor chamber and including a motor shaft having a flow passage formed at its axis, the motor having one end on one side in an axial direction of the motor shaft positioned in the gear chamber; a gear unit housed in the gear chamber and mechanically connected to the one end of the motor shaft; an electric unit accommodated in the electric unit chamber and electrically connected to the motor; a heat medium passage that supplies the heat medium stored in the gear chamber to the flow path of the motor shaft; Equipped with At least a portion of the electric unit chamber is located on one side in the axial direction relative to the one end of the motor shaft, The heat medium path is connected to the flow path of the motor shaft at the one end of the motor shaft. Drive unit.

2. The drive unit according to claim 1 , wherein at least a portion of the electric unit chamber is located on one side in the axial direction relative to the heat medium path.

3. The drive device according to claim 2 , wherein at least a portion of the electric unit chamber overlaps with the gear chamber in a direction perpendicular to the axial direction.

4. The drive device according to claim 3 , wherein at least a portion of the electric unit chamber overlaps with the motor chamber in the axial direction.

5. The drive unit according to claim 1 , wherein at least a portion of the heat medium path is located on one axial side of the gear chamber.

6. a part of the electric unit chamber is located on an extension line of the motor shaft toward one axial side, the one end of the motor shaft is supported by a partition wall between the gear chamber and the electric unit chamber, The drive unit according to claim 5 , wherein the heat medium path passes through the electric unit chamber and penetrates the partition wall to be connected to the flow path.

7. The drive unit according to claim 6 , wherein the heat medium path extends from an exterior of the casing, through a wall surface of the casing that defines the electric unit chamber, into the electric unit chamber.

8. The drive device further includes a pump that sends the heat medium stored in a lower portion of the gear chamber to the heat medium path, The drive unit according to claim 1 , wherein the pump is located on one axial side or the other axial side with respect to the gear chamber.

9. The heat transfer medium cooler is further provided on the heat transfer medium path and configured to cool the heat transfer medium. The drive unit according to claim 8 , wherein the heat medium cooler is located on one axial side or the other axial side with respect to the gear chamber.

10. the motor chamber and the gear chamber are connected by a communication hole through which the heat medium can flow, The drive device according to claim 1 , wherein the electric unit chamber is liquid-tightly isolated from the motor chamber and the gear chamber.

11. the casing includes a motor case having the motor chamber, a gear case defining at least a portion of the gear chamber, and an electric unit case defining at least a portion of the electric unit chamber, The drive unit according to claim 1 , wherein the gear case and the electric unit case are fastened to the motor case by a plurality of fastening members.

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