Drive unit

Abstract

To provide a drive unit capable of cooling a torque converter.SOLUTION: A drive unit 100 includes a prime mover 2, a torque converter 3, and a torque converter case 4. The torque converter 3 is configured to amplify torque from the prime mover 2. The torque converter 3 is disposed in a rotatable manner. The torque converter case 4 is disposed in a manner that the torque converter case 4 cannot rotate. The torque converter case 4 houses the torque converter 3. The torque converter case 4 has a first air supply port 41 and a first exhaust port 42. The first air supply port 41 is configured to introduce air into the interior. The first exhaust port 42 is configured to exhaust air at the interior.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a drive unit. [Background technology]

[0002] In order to amplify the torque of a prime mover such as an electric motor or an engine, a drive unit having a torque converter has been proposed. The torque converter has an impeller, a turbine, and a stator. A hydraulic oil is filled between the impeller and the turbine, and torque is transmitted from the impeller to the turbine via the hydraulic oil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-188732 A Summary of the Invention [Problem to be solved by the invention]

[0004] The torque converter generates heat when the impeller and the turbine rotate at different rotational speeds or when the lock-up clutch is in a slipping state. Therefore, an object of the present invention is to provide a drive unit capable of cooling the torque converter. [Means for solving the problem]

[0005] A drive unit according to a first aspect includes a prime mover, a torque converter, and a torque converter case. The torque converter is configured to amplify torque from the prime mover. The torque converter is rotatably arranged. The torque converter case is non-rotatably arranged. The torque converter case houses the torque converter. The torque converter case has a first air intake port and a first exhaust port. The first air intake port is configured to introduce air into the interior of the torque converter case. The first exhaust port is configured to exhaust air from the interior of the torque converter case.

[0006] As described above, the torque converter case has the first air intake port and the first exhaust port, so that fresh air is supplied into the torque converter case. The torque converter can be cooled by heat exchange between the air in the torque converter case and the torque converter. In addition, the heat generated by the torque converter can be effectively utilized by supplying the air discharged from the first exhaust port to the interior of the vehicle or to the battery.

[0007] The drive unit according to the second aspect is the drive unit according to the first aspect, and is configured as follows: The first exhaust port is disposed above the first air intake port. With this configuration, air inside the torque converter case can be efficiently exhausted.

[0008] The drive unit according to the third aspect is the drive unit according to the first or second aspect, and is configured as follows. The first exhaust port is disposed radially outward from the first air inlet. With this configuration, an air flow from the first air inlet to the first exhaust port can be efficiently generated.

[0009] A drive unit according to a fourth aspect is the drive unit according to any one of the first to third aspects, and is configured as follows: The prime mover is an electric motor.

[0010] A drive unit according to a fifth aspect is the drive unit according to the fourth aspect, and is configured as follows: the electric motor has a rotor, a motor stator, and a motor case. The rotor is rotatably arranged. The motor stator is arranged at a distance from the rotor in the radial direction. The motor case houses the rotor and the motor stator. The motor case includes a second air inlet and a second exhaust port. The second air inlet is configured to introduce air into the interior of the motor case. The second exhaust port is configured to exhaust air from the interior of the motor case.

[0011] A drive unit according to a sixth aspect is the drive unit according to the fifth aspect, and is configured as follows. The second air inlet is disposed at an interval from the second exhaust port in the axial direction. The rotor and the motor stator are disposed between the second air inlet and the second exhaust port in the axial direction. With this configuration, it is possible to generate an airflow that passes between the rotor and the motor stator.

[0012] A drive unit according to a seventh aspect is the drive unit according to any one of the first to sixth aspects, further comprising an exhaust flow path extending from the first exhaust port to an object to be heated.

[0013] The drive unit according to an eighth aspect is the drive unit according to the seventh aspect, further comprising a circulation flow path. The circulation flow path is configured to return the air, after being sent to the object to be heated, to the first air supply port.

[0014] A drive unit according to a ninth aspect is the drive unit according to any one of the first to eighth aspects, further comprising a blower. The blower is configured to supply air into the torque converter case through the first air supply port. Effect of the Invention

[0015] According to the present invention, the torque converter can be cooled. [Brief description of the drawings]

[0016] [Figure 1]FIG. [Diagram 2] FIG. 11 is a schematic diagram of a drive unit according to a modified example. [Diagram 3] FIG. 11 is a schematic diagram of a drive unit according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the drive unit will be described with reference to the drawings. Fig. 1 is a schematic diagram of the drive unit according to this embodiment. In the following description, the axial direction is the direction in which the rotation shaft O of the prime mover or torque converter 3 extends. The circumferential direction is the circumferential direction of a circle centered on the rotation shaft O, and the radial direction is the radial direction of a circle centered on the rotation shaft O. The forward rotation is the rotation when the vehicle moves forward, and the reverse rotation is the rotation when the vehicle moves backward.

[0018] [Drive unit 100] As shown in Fig. 1, the drive unit 100 includes an electric motor 2 (an example of a prime mover), a torque converter 3, a torque converter case 4, a first drive shaft 5, a second drive shaft 6, an inverter 20, a battery 7, a first exhaust flow path 81 (an example of an exhaust flow path), a second exhaust flow path 82, a third exhaust flow path 83, and a reduction gear 9. The drive unit 100 is mounted on, for example, an electric vehicle. The drive unit 100 is configured to drive drive wheels (not shown). In this embodiment, the battery 7 is the object to be heated.

[0019] <Electric motor 2> The electric motor 2 has a motor case 21, a motor stator 22, and a rotor 23. The electric motor 2 in this embodiment is a so-called inner rotor type motor. The motor case 21 is fixed to a vehicle body frame or the like and cannot rotate. The motor stator 22 and the rotor 23 are housed within this motor case 21.

[0020] The motor stator 22 is fixed to an inner circumferential surface of the motor case 21. The motor stator 22 is non-rotatable. The rotor 23 rotates around a rotation axis O. The rotor 23 is disposed radially inside the motor stator 22. The motor stator 22 is disposed with a gap between it and the rotor 23 in the radial direction.

[0021] The motor case 21 has a second air supply port 211 and a second exhaust port 212. Each of the second air supply port 211 and the second exhaust port 212 is formed by at least one through hole that penetrates the motor case 21 and communicates between the inside and the outside of the motor case 21.

[0022] The second air intake port 211 is configured to introduce air into the motor case 21. Fresh air is supplied into the motor case 21 through the second air intake port 211.

[0023] The second exhaust port 212 is configured to exhaust the air inside the motor case 21 to the outside of the motor case 21. The air inside the motor case 21 is exhausted to the outside of the motor case 21 via the second exhaust port 212.

[0024] The second air intake port 211 is disposed at an interval from the second exhaust port 212 in the axial direction. The motor stator 22 and the rotor 23 are disposed between the second air intake port 211 and the second exhaust port 212 in the axial direction. For this reason, air introduced into the motor case 21 from the second air intake port 211 passes between the motor stator 22 and the rotor 23 and flows to the second exhaust port 212. Note that the axial direction here is the direction in which the rotating shaft of the electric motor 2 extends.

[0025] The second exhaust port 212 is disposed above the second air supply port 211. The second exhaust port 212 opens upward. The second air supply port 211 opens downward.

[0026] <Inverter 20> The inverter 20 is configured to control the rotation speed of the electric motor 2. The inverter 20 has an inverter body 201 and an inverter case 202. The inverter body 201 is configured by a printed wiring board, conductive elements, and the like.

[0027] Inverter case 202 is configured to house inverter main body 201. Inverter case 202 has third air supply port 203 and third exhaust port 204. Each of third air supply port 203 and third exhaust port 204 is configured by at least one through hole that penetrates inverter case 202 and communicates between the inside and outside of inverter case 202.

[0028] The third air intake port 203 is configured to introduce air into the inverter case 202. Fresh air is supplied into the inverter case 202 through the third air intake port 203.

[0029] The third exhaust port 204 is configured to exhaust the air inside the inverter case 202 to the outside of the inverter case 202. The air inside the inverter case 202 is exhausted to the outside of the inverter case 202 via the third exhaust port 204.

[0030] <Torque converter 3> The torque converter 3 is disposed axially apart from the electric motor 2. A reduction gear 9 is disposed between the torque converter 3 and the electric motor 2. The electric motor 2, the reduction gear 9, and the torque converter 3 are arranged in this order in the axial direction.

[0031] The torque converter 3 is rotatably arranged. A rotation axis O of the torque converter 3 substantially coincides with a rotation axis O of the electric motor 2. The torque converter 3 receives torque from the electric motor 2. The torque converter 3 is configured to amplify the torque output by the electric motor 2.

[0032] The torque converter 3 further includes a cover 31, an impeller 32, a turbine 33, a stator 34, a first one-way clutch 36, and a centrifugal clutch 37 (an example of a lock-up clutch). In this embodiment, the outer shell of the torque converter 3 is formed by the cover 31 and the impeller 32.

[0033] In the torque converter 3, an impeller 32 is disposed on the electric motor 2 side (left side in FIG. 1), and a cover 31 is disposed on the opposite side to the electric motor 2 (right side in FIG. 1). The torque converter 3 is housed in a torque converter case 4. A working fluid is supplied to the torque converter 3. The working fluid is, for example, hydraulic oil. The space within the torque converter 3 and the space within the torque converter case 4 are separated airtightly. Therefore, the working fluid in the torque converter 3 does not leak into the torque converter case 4.

[0034] Torque from the electric motor 2 is input to the cover 31. The cover 31 rotates due to the torque from the electric motor 2. The cover 31 is fixed to the first drive shaft 5. For example, the cover 31 has a splined hole, and the first drive shaft 5 is spline-fitted into the splined hole of the cover 31. Therefore, the cover 31 rotates integrally with the first drive shaft 5. The cover 31 is disposed so as to cover the turbine 33.

[0035] The impeller 32 rotates integrally with the cover 31. Torque from the electric motor 2 is input to the impeller 32 via the cover 31. The impeller 32 is fixed to the cover 31. The impeller 32 is rotatably supported by a fixed shaft 104 via a bearing member (not shown). The fixed shaft 104 is cylindrical. The space between the impeller 32 and the fixed shaft 104 is airtightly sealed. The second drive shaft 6 extends axially within the fixed shaft 104. The fixed shaft 104 extends, for example, from the reducer case 92 or the torque converter case 4. The fixed shaft 104 is non-rotatable.

[0036] The turbine 33 is disposed opposite the impeller 32. In particular, the turbine 33 faces the impeller 32 in the axial direction. Torque is transmitted to the turbine 33 from the impeller 32 via the working fluid.

[0037] A second drive shaft 6 is attached to the turbine 33. In detail, the second drive shaft 6 is spline-fitted to the turbine 33. The turbine 33 rotates integrally with the second drive shaft 6.

[0038] The stator 34 is configured to straighten the hydraulic oil returning from the turbine 33 to the impeller 32. The stator 34 is rotatable around a rotation axis O. For example, the stator 34 is supported by a fixed shaft 104 via a first one-way clutch 36. The stator 34 is disposed between the impeller 32 and the turbine 33 in the axial direction.

[0039] The first one-way clutch 36 is disposed between the fixed shaft 104 and the stator 34. The first one-way clutch 36 is configured to allow the stator 34 to rotate in the forward rotation direction. On the other hand, the first one-way clutch 36 prevents the stator 34 from rotating in the reverse rotation direction. The torque is amplified by the stator 34 and transmitted from the impeller 32 to the turbine 33.

[0040] The centrifugal clutch 37 is attached to the turbine 33 or the second drive shaft 6. The centrifugal clutch 37 rotates integrally with the turbine 33. The centrifugal clutch 37 is configured to connect the cover 31 and the turbine 33 by centrifugal force generated by the rotation of the turbine 33. In detail, the centrifugal clutch 37 is configured to transmit torque from the cover 31 to the turbine 33 when the turbine 33 reaches or exceeds a predetermined rotation speed.

[0041] <Reducer 9> The reducer 9 is disposed between the electric motor 2 and the torque converter 3 in the axial direction. The reducer 9 transmits the torque from the torque converter 3 to the drive wheels. More specifically, the reducer 9 amplifies the torque from the torque converter 3 and transmits it to the drive wheels. The reducer 9 has a plurality of gears 91. The reducer 9 is housed in a reducer case 92. One of the plurality of gears 91 meshes with a gear 61 fixed to the second drive shaft 6.

[0042] <First drive shaft 5> The first drive shaft 5 extends in the axial direction from the electric motor 2. Specifically, the first drive shaft 5 extends from the rotor 23 of the electric motor 2. If the electric motor 2 has an output shaft, the first drive shaft 5 is attached to the output shaft of the electric motor 2. The rotation axis of the first drive shaft 5 is substantially collinear with the rotation axis of the electric motor 2 and the rotation axis of the torque converter 3.

[0043] The first drive shaft 5 transmits torque between the electric motor 2 and the torque converter 3. More specifically, the first drive shaft 5 transmits torque from the electric motor 2 to the torque converter 3. The first drive shaft 5 is connected to an impeller 32 of the torque converter 3. More specifically, the first drive shaft 5 is connected to the impeller 32 via a cover 31. A tip end of the first drive shaft 5 is attached to the cover 31 of the torque converter 3.

[0044] <Second drive shaft 6> The second drive shaft 6 transmits torque between the torque converter 3 and the reduction gear 9. The second drive shaft 6 transmits torque from the torque converter 3 to the drive wheels. In detail, the second drive shaft 6 outputs the torque from the torque converter 3 to the reduction gear 9. The second drive shaft 6 extends in the axial direction from the torque converter 3 toward the electric motor 2.

[0045] The second drive shaft 6 is cylindrical. The first drive shaft 5 extends inside the second drive shaft 6. The first drive shaft 5 is solid. One end (the right end in FIG. 1) of the second drive shaft 6 is attached to the turbine 33 of the torque converter 3. A gear 61 is attached to the other end of the second drive shaft 6. The second drive shaft 6 is rotatably supported, for example, by a reduction gear case 92 or the like via a bearing member or the like.

[0046] <Second one-way clutch 50> The drive unit 100 further includes a second one-way clutch 50. The second one-way clutch 50 is disposed between the first drive shaft 5 and the second drive shaft 6. More specifically, the second one-way clutch 50 is disposed between the cover 31 and the turbine 33. The second one-way clutch 50 allows the first drive shaft 5 to rotate relative to the second drive shaft 6 in the forward rotation direction. That is, the second one-way clutch 50 is configured such that the first drive shaft 5 rotates relative to the second drive shaft 6 when the electric motor 2 rotates forward so that the vehicle moves forward. Therefore, when the vehicle moves forward, the second one-way clutch 50 does not transmit torque from the first drive shaft 5 to the second drive shaft 6.

[0047] On the other hand, the second one-way clutch 50 rotates the first drive shaft 5 integrally with the second drive shaft 6 in the reverse rotation direction. That is, the second one-way clutch 50 is configured so that when the electric motor 2 rotates in reverse to move the vehicle backwards, the first drive shaft 5 rotates integrally with the second drive shaft 6. Therefore, when the vehicle moves backwards, the second one-way clutch 50 transmits torque from the first drive shaft 5 to the second drive shaft 6. That is, when the vehicle moves backwards, the torque of the electric motor 2 is transmitted from the first drive shaft 5 to the second drive shaft 6 via the second one-way clutch 50 without passing through the torque converter 3.

[0048] <Torque converter case 4> The torque converter case 4 houses the torque converter 3. The torque converter case 4 and the outer shell of the torque converter 3 are disposed with a gap between them. Therefore, an air layer is formed between the torque converter case 4 and the outer shell of the torque converter 3.

[0049] The torque converter case 4 is arranged so as to be non-rotatable, and is fixed to, for example, a vehicle body frame or the like.

[0050] The torque converter case 4 has a first air intake port 41 and a first exhaust port 42. Each of the first air intake port 41 and the first exhaust port 42 is formed by at least one through hole that penetrates the torque converter case 4 and communicates between the inside and the outside of the torque converter case 4.

[0051] The first air intake port 41 is configured to introduce air into the interior of the torque converter case 4. Fresh air is supplied into the torque converter case 4 via this first air intake port 41.

[0052] The first exhaust port 42 is configured to exhaust air inside the torque converter case 4. The air inside the torque converter case 4 is exhausted to the outside of the torque converter case 4 via the first exhaust port 42.

[0053] The first exhaust port 42 is disposed above the first air supply port 41. The opening direction of the first air supply port 41 and the opening direction of the first exhaust port 42 are different from each other. Specifically, the first exhaust port 42 opens upward. And the first air supply port 41 opens downward. The air introduced from the first air supply port 41 flows in the space between the torque converter case 4 and the torque converter 3, and is discharged from the first exhaust port 42.

[0054] <Battery> The battery 7 is configured to exchange electric power with the electric motor 2. That is, the battery 7 is electrically connected to the electric motor 2, and supplies electric power to the electric motor 2 and stores electric power generated by the rotation of the electric motor 2. In detail, the battery 7 is connected to the electric motor 2 via an inverter 20.

[0055] <First exhaust passage 81> The first exhaust flow path 81 extends from the first exhaust port 42 to the battery 7. Air discharged from the first exhaust port 42 flows through the first exhaust flow path 81. For example, the first exhaust flow path 81 is a pipe that passes air inside. Air heated in the torque converter case 4 is sent to the battery 7 via the first exhaust flow path 81 to heat the battery 7. The first exhaust flow path 81 may extend to the interior of the vehicle cabin via the battery 7. Alternatively, the first exhaust flow path 81 may extend to the interior of the vehicle cabin instead of to the battery 7.

[0056] <Second exhaust passage 82> The second exhaust flow path 82 extends from the second exhaust port 212 to the battery 7. Air discharged from the second exhaust port 212 flows through the second exhaust flow path 82. For example, the second exhaust flow path 82 is a pipe that passes air inside. Air heated in the motor case 21 is sent to the battery 7 via the second exhaust flow path 82 to heat the battery 7. The second exhaust flow path 82 may extend to the interior of the vehicle cabin via the battery 7. Alternatively, the second exhaust flow path 82 may extend to the interior of the vehicle cabin instead of to the battery 7.

[0057] <Third exhaust passage 83> The third exhaust flow path 83 extends from the third exhaust port 204 to the battery 7. Air discharged from the third exhaust port 204 flows through the third exhaust flow path 83. For example, the third exhaust flow path 83 is a pipe that passes air inside. Air heated in the inverter case 202 is sent to the battery 7 via the third exhaust flow path 83 to heat the battery 7. The third exhaust flow path 83 may extend to the interior of the vehicle cabin via the battery 7. Alternatively, the third exhaust flow path 83 may extend to the interior of the vehicle cabin instead of to the battery 7.

[0058] <Blower 84> The blower 84 is configured to supply air into the torque converter case 4 through the first air supply port 41. In detail, the blower 84 supplies air into the torque converter case 4 through the first supply passage 85 and the first air supply port 41.

[0059] Moreover, the blower 84 is configured to supply air into the motor case 21 through the second air supply port 211. In detail, the blower 84 supplies air into the motor case 21 through the second supply passage 86 and the second air supply port 211.

[0060] Moreover, the blower 84 is configured to supply air into the motor case 21 through the third air supply port 203. In detail, the blower 84 supplies air into the motor case 21 through the third supply passage 87 and the third air supply port 203.

[0061] [Variations] Although the embodiment of the present invention has been described above, the present invention is not limited to these, and various modifications are possible without departing from the spirit of the present invention. Note that the following modifications can basically be applied simultaneously.

[0062] (a) In the above embodiment, the electric motor 2 is given as an example of a prime mover, but the prime mover of the drive unit 100 is not limited to the electric motor 2. For example, an engine may be used as the prime mover of the drive unit 100.

[0063] (b) In the above embodiment, both the first air intake port 41 and the first exhaust port 42 are disposed on the outer periphery of the torque converter case 4, but the positions of the first air intake port 41 and the first exhaust port 42 are not limited thereto. For example, as shown in FIG. 2, the first exhaust port 42 may be disposed radially outward of the first air intake port 41. Specifically, the first exhaust port 42 is formed on the outer periphery of the torque converter case 4. The first air intake port 41 is formed in the center of the torque converter case 4 in the radial direction. The first air intake port 41 opens along the axial direction. Specifically, the first air intake port 41 is disposed so as to face the rotation shaft of the torque converter 3.

[0064] As shown in FIG. 2, the first air supply port 41 may be open in the axial direction, and the first exhaust port 42 may be open in the radial direction.

[0065] 3, the drive unit 100 may further include a circulation flow path 88. The circulation flow path 88 is configured to return air sent to a heating target such as the battery 7 or the vehicle interior to the first air intake port 41. In detail, the circulation flow path 88 is connected to the first air intake port 41 via a blower 84 and a first supply flow path 85. [Explanation of symbols]

[0066] 2: Electric motor 21: Motor case 211: 2nd air supply port 212: Second exhaust port 22: Motor stator 23: Rotor 3: Torque converter 32: Impeller 33: Turbine 4: Torque converter case 41: 1st air supply port 42: First exhaust port 81: First exhaust passage 84: Blower 88: Circulation flow path 100: Drive unit

Claims

1. The prime mover, a rotatably disposed torque converter configured to amplify torque from the prime mover; a torque converter case that houses the torque converter and is arranged non-rotatably, the torque converter case having a first air intake port configured to introduce air therein and a first exhaust port configured to exhaust air therein; A drive unit comprising:

2. The first exhaust port is disposed above the first air intake port.

2. A drive unit according to claim 1.

3. The first exhaust port is disposed radially outward of the first intake port.

2. A drive unit according to claim 1.

4. The prime mover is an electric motor.

2. A drive unit according to claim 1.

5. The electric motor is A rotor that is rotatably disposed; a motor stator disposed radially apart from the rotor; a motor case including a second air inlet configured to introduce air thereinto and a second air outlet configured to exhaust air therefrom, the motor case housing the rotor and the motor stator; 5. The drive unit according to claim 4, having:

6. The second air supply port is disposed at a distance from the second exhaust port in the axial direction, The rotor and the motor stator are disposed between the second air supply port and the second exhaust port in the axial direction. A drive unit according to claim 5.

7. Further comprising an exhaust flow path extending from the first exhaust port to a heating target.

2. A drive unit according to claim 1.

8. Further comprising a circulation flow path configured to return the air after being sent to the heating target to the first air supply port. A drive unit according to claim 7.

9. a blower configured to supply air into the torque converter case through the first air supply port, 2. A drive unit according to claim 1.

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