Drive unit

Abstract

To improve driving force in backward movement.SOLUTION: A drive unit 100 includes a first drive unit 1 and a second drive unit 2. The first drive unit 1 includes a first electric motor 10 and a first torque converter 11. The first electric motor 10 is configured to rotate in a first rotational direction and in a second rotational direction. The first torque converter 11 is configured to amplify torque of the first electric motor 10 in the first rotational direction. The second drive unit 2 includes a second electric motor 20 and a second torque converter 21. The second electric motor 20 is configured to rotate in the first rotational direction and in the second rotational direction. The second torque converter 21 is configured to amplify torque of the second electric motor 20 in the second rotational direction.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] An electric vehicle travels using an electric motor as a drive source. The drive unit described in Patent Document 1 moves forward by rotating the electric motor forward and moves backward by rotating the electric motor backward. Further, this drive unit has a torque converter in order to amplify the torque from the electric motor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an electric vehicle as described above, the driving force during forward movement can be ensured. However, in commercial vehicles and the like, a driving force is also required during backward movement.

[0005] Therefore, an object of the present invention is to improve the driving force during backward movement.

Means for Solving the Problems

[0006] The drive unit according to the first embodiment is configured to move a vehicle forward and backward. This drive unit according to the first embodiment comprises a first drive unit and a second drive unit. The first drive unit has a first electric motor and a first torque converter. The first electric motor is configured to rotate in a first rotational direction and a second rotational direction. The first rotational direction is the rotational direction that moves the vehicle forward, and the second rotational direction is the rotational direction that moves the vehicle backward. The first torque converter is configured to amplify the torque of the first electric motor in the first rotational direction. The second drive unit has a second electric motor and a second torque converter. The second electric motor is configured to rotate in a first rotational direction and a second rotational direction. The second torque converter is configured to amplify the torque of the second electric motor in the second rotational direction.

[0007] In this configuration, the torque of the first electric motor in the first rotational direction is amplified by the first torque converter. Therefore, the driving force can be improved during forward movement. Furthermore, the torque of the second electric motor in the second rotational direction is amplified by the second torque converter. This makes it possible to improve the driving force even during reverse movement.

[0008] The drive unit according to the second embodiment is the drive unit according to the first embodiment, wherein the first drive unit has a first clutch. The first clutch is configured to transmit torque in the second rotation direction of the first electric motor and to interrupt the transmission of torque in the first rotation direction of the first electric motor.

[0009] The drive unit according to the third embodiment is a drive unit according to the first or second embodiment in which the second drive unit has a second clutch. The second clutch is configured to transmit torque in the first rotational direction of the second electric motor and to interrupt the transmission of torque in the second rotational direction of the second electric motor.

[0010] In the fourth embodiment, the drive unit is characterized in that, in any of the first to third embodiments, the positional relationship between the first drive unit and the second drive unit is different, between each electric motor and each torque converter.

[0011] In the fifth embodiment, the drive unit is such that, in any of the first to third embodiments, the positional relationship between the first drive unit and the second drive unit is the same as that between the electric motor and the torque converter.

[0012] The drive unit according to the sixth embodiment further comprises a power transmission mechanism in addition to the drive unit according to the fifth embodiment. The power transmission mechanism is configured to transmit torque from the first drive unit and the second drive unit to the output unit. The power transmission mechanism has a reversing gear. The reversing gear reverses the rotation of the first electric motor or the second electric motor and outputs it to the output unit.

[0013] The drive unit according to the seventh embodiment further comprises a control unit in addition to the drive unit according to any of the first to sixth embodiments. The control unit is configured to control a first electric motor and a second electric motor. The control unit executes a first forward mode. The first forward mode rotates the first electric motor in a first rotational direction and rotates the second electric motor in a first rotational direction.

[0014] In the drive unit according to the eighth embodiment, the control unit executes a second forward mode. In the second forward mode, the first electric motor rotates in a first rotational direction and the second electric motor is stopped.

[0015] In the drive unit according to the ninth embodiment, the control unit executes a third forward mode, as in the drive unit according to the seventh or eighth embodiment. In the third forward mode, the first electric motor is made to idle, and the second electric motor is made to rotate in the first rotational direction.

[0016] In the drive unit according to the 10th embodiment, the control unit in the drive unit according to any of the 7th to 9th embodiments executes a first braking mode. In the first braking mode, when moving forward and decelerating, the first electric motor is regenerated and the second electric motor is stopped.

[0017] The drive unit according to the 11th aspect is the drive unit according to any one of the 7th to 10th aspects, wherein the control unit executes the second braking mode. The second braking mode regenerates the first electric motor and rotates the second electric motor in the second rotation direction when moving forward and decelerating.

[0018] The drive unit according to the 12th aspect is the drive unit according to any one of the 7th to 11th aspects, wherein the control unit executes the first reverse mode. The first reverse mode rotates the first electric motor in the second rotation direction and rotates the second electric motor in the second rotation direction when moving backward. The drive unit according to the 13th aspect is the drive unit according to any one of the 7th to 12th aspects, wherein the control unit executes the second reverse mode. The second reverse mode stops the first electric motor and rotates the second electric motor in the second rotation direction.

[0019]

Advantages of the Invention

[0020] According to the present invention, it is possible to obtain a driving force even when moving backward.

Brief Description of the Drawings

[0021] [Figure 1] Block diagram showing the torque transmission path of the drive unit. [Figure 2] Schematic diagram of the drive unit. [Figure 3] Schematic diagram of the drive unit according to the modified example.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, embodiments of the drive unit will be described while referring to the drawings. FIG. 1 is a block diagram showing the torque transmission path of the drive unit, and FIG. 2 is a schematic diagram of the drive unit. In the following description, the first rotation direction is the rotation direction of each member when the vehicle is moving forward, and the second rotation direction is the rotation direction of each member when the vehicle is moving backward. Also, the front-rear direction of the vehicle is the front and rear with reference to the state where the driver is sitting on the seat. Specifically, the left-right direction in FIG. 2 is the front-rear direction. The front of the vehicle is the front with reference to the state where the driver is sitting on the seat. Specifically, the left in FIG. 2 is the front.

[0023] [Drive Unit] The drive unit 100 is mounted on the vehicle. The drive unit 100 is configured to move the vehicle forward and backward. As shown in FIGS. 1 and 2, the drive unit 100 mounted on the vehicle includes a first drive unit 1, a second drive unit 2, a power transmission mechanism 3, and a control unit 4. The drive unit is configured to drive an output unit 5. Note that the output unit 5 includes a differential gear 51, a pair of drive shafts 52, and drive wheels 53. The output unit 5 may have only the drive wheels 53.

[0024] [First Drive Unit] The first drive unit 1 is configured to drive the output unit 5. The first drive unit 1 includes a first electric motor 10, a first torque converter 11, a first clutch 12, and a first transmission shaft 13. The first drive unit 1 is arranged in the order of the first electric motor 10 and the first torque converter 11 from the front of the vehicle.

[0025] The first electric motor 10 is configured to rotate in a first rotational direction. The first electric motor 10 is also configured to rotate in a second rotational direction. The vehicle moves forward when the first electric motor 10 rotates in the first rotational direction, and the vehicle moves backward when the first electric motor 10 rotates in the second rotational direction. The torque of the first electric motor 10 in the first rotational direction is transmitted to the first transmission shaft 13 via the first torque converter 11, and the torque of the first electric motor 10 in the second rotational direction is transmitted to the first transmission shaft 13 via the first clutch 12.

[0026] The first electric motor 10 includes a first motor case 101, a first motor stator 102, and a first rotor 103. The first motor case 101 is fixed to the vehicle frame or the like and is not rotatable.

[0027] The first motor stator 102 is fixed to the inner circumferential surface of the first motor case 101. The first motor stator 102 is non-rotatable. The first rotor 103 rotates around the rotation axis O. The first rotor 103 is positioned radially inside the first motor stator 102. In other words, the first electric motor 10 is a so-called inner rotor type.

[0028] The first torque converter 11 receives the torque from the first electric motor 10 as input. The first torque converter 11 is configured to amplify the torque of the first electric motor 10 in the first rotational direction. That is, when the first electric motor 10 rotates in the first rotational direction, the first torque converter 11 amplifies the torque in that first rotational direction and transmits it to the first transmission shaft 13. The first torque converter 11 does not amplify the torque of the first electric motor 10 in the second rotational direction. The first torque converter 11 outputs the amplified torque to the first transmission shaft 13.

[0029] The first torque converter 11 includes a first cover 110, a first impeller 111, a first turbine 112, and a first stator 113. The first torque converter 11 also has a lock-up clutch 115 that directly transmits torque from the first electric motor 10 to the first turbine 112. The torque output from the first turbine 112 is then transmitted to the first transmission shaft 13.

[0030] The first clutch 12 is located within the first torque converter 11. The first clutch 12 transmits the torque of the first electric motor 10 in the second rotational direction to the first transmission shaft 13. On the other hand, the first clutch 12 also blocks the transmission of the torque of the first electric motor 10 in the first rotational direction to the first transmission shaft 13. That is, when the first electric motor 10 rotates in the second rotational direction, the first clutch 12 transmits the torque in the second rotational direction to the first transmission shaft 13. Then, when the first electric motor 10 rotates in the first rotational direction, the first torque converter 11 transmits the torque in the first rotational direction to the first transmission shaft 13. The first clutch 12 is configured, for example, as a one-way clutch.

[0031] [Second drive unit] The second drive unit 2 is configured to drive the output unit 5. The second drive unit 2 is arranged along the longitudinal direction of the vehicle with respect to the first drive unit 1. In this embodiment, the rotation axis of the first drive unit 1 and the rotation axis of the second drive unit 2 are arranged coaxially. The second drive unit 2 includes a second electric motor 20, a second torque converter 21, a second clutch 22, and a second transmission shaft 23. In the second drive unit 2, the second torque converter 21 and the second electric motor 20 are arranged in that order from the front of the vehicle. In other words, the positional relationship between the electric motors 10, 20 and the torque converters 11, 21 is different in the first drive unit 1 and the second drive unit 2.

[0032] The second electric motor 20 is configured to rotate in a first rotational direction and a second rotational direction. When the second electric motor 20 rotates in the first rotational direction, the vehicle moves forward, and when the second electric motor 20 rotates in the second rotational direction, the vehicle moves backward. When viewed from the front of the vehicle (left side in Figure 2), the first rotational direction of the first electric motor 10 and the first rotational direction of the second electric motor 20 are the same. For example, when viewed from the left side of Figure 2, if the first electric motor 10 is configured to move forward when it rotates clockwise, the vehicle will also move forward when the second electric motor 20 rotates clockwise when viewed from the left side of Figure 2.

[0033] The torque of the second electric motor 20 in the second rotational direction is transmitted to the second transmission shaft 23 via the second torque converter 21, and the torque of the second electric motor 20 in the first rotational direction is transmitted to the second transmission shaft 23 via the second clutch 22.

[0034] The second electric motor 20 includes a second motor case 201, a second motor stator 202, and a second rotor 203. Since the structure of the second electric motor 20 is substantially the same as that of the first electric motor 10, a detailed description is omitted.

[0035] The second torque converter 21 receives the torque from the second electric motor 20. The second torque converter 21 is configured to amplify the torque of the second electric motor 20 in the second rotational direction. That is, when the second electric motor 20 rotates in the second rotational direction, the second torque converter 21 amplifies the torque in that second rotational direction and transmits it to the second transmission shaft 23. The second torque converter 21 does not amplify the torque of the second electric motor 20 in the first rotational direction.

[0036] The second torque converter 21 includes a second impeller 211, a second turbine 212, a second stator 213, and a second clutch 22. Unlike the first torque converter 11, the second torque converter 21 does not have a lock-up clutch, although it may have one. The output from the second turbine 212 is transmitted to the second transmission shaft 23.

[0037] The second clutch 22 is located within the second torque converter 21. The second clutch 22 transmits the torque of the second electric motor 20 in the first rotational direction to the second transmission shaft 23. On the other hand, the second clutch 22 also blocks the transmission of the torque of the second electric motor 20 in the second rotational direction to the second transmission shaft 23. That is, when the second electric motor 20 rotates in the first rotational direction, the second clutch 22 transmits the torque in that first rotational direction to the output unit 5. Then, when the second electric motor 20 rotates in the second rotational direction, the second torque converter 21 transmits the torque in that second rotational direction to the second transmission shaft 23. The second clutch 22 is configured, for example, as a one-way clutch.

[0038] [Power transmission mechanism] The power transmission mechanism 3 is configured to transmit torque from the first drive unit 1 and the second drive unit 2 to the output unit 5. Furthermore, the power transmission mechanism 3 is configured to combine the torque from the first drive unit 1 and the torque from the second drive unit 2 and transmit them to the output unit 5. The power transmission mechanism 3 includes a first gear train 31, a second gear train 32, and an output shaft 35.

[0039] The first gear train 31 transmits torque from the first drive unit 1. The first gear train 31 includes a first input gear 31a and a first output gear 31b. The first input gear 31a meshes with the first output gear 31b. The first input gear 31a is mounted on the first transmission shaft 13. The first output gear 31b is mounted on the output shaft 35.

[0040] The second gear train 32 transmits torque from the second drive unit 2. The second gear train 32 includes a second input gear 32a and a second output gear 32b. The second input gear 32a meshes with the second output gear 32b. The second input gear 32a is mounted on the second transmission shaft 23. The second output gear 32b is mounted on the output shaft 35.

[0041] The gear ratio of the first gear train 31 is the same as the gear ratio of the second gear train 32. The gear ratios of both the first gear train 31 and the second gear train 32 are greater than 1. In other words, the power transmission mechanism 3 functions as a reduction gear. The gear ratio of the first gear train 31 may be different from the gear ratio of the second gear train 32. In this case, it is preferable that the gear ratio of the first gear train 31 is greater than the gear ratio of the second gear train 32. The gear ratio of the first gear train 31 may also be smaller than the gear ratio of the second gear train 32.

[0042] [Control Unit] The control unit 4 is configured to control the first electric motor 10 and the second electric motor 20. The control unit 4 is composed of a computer (e.g., a microcomputer) equipped with a CPU (Central Processing Unit) and ROM (Read Only Memory), etc. The ROM stores programs for performing various calculations. The CPU executes the programs stored in the ROM.

[0043] First, let's explain the operation of the control unit 4 during forward movement. During forward movement, the control unit 4 executes the first forward mode, the second forward mode, the third forward mode, the first braking mode, and the second braking mode.

[0044] First, let's describe the first forward mode. In the first forward mode, the control unit 4 drives both the first drive unit 1 and the second drive unit 2 to move the vehicle forward. Specifically, the control unit 4 rotates the first electric motor 10 in a first rotational direction and also rotates the second electric motor 20 in a first rotational direction.

[0045] As a result, the torque of the first electric motor 10 is amplified by the first torque converter 11 and transmitted to the output unit 5. The torque of the second electric motor 20 is also transmitted to the output unit 5 via the second clutch 22. The torque of the second electric motor 20 is not amplified by the second torque converter 21. In other words, the second electric motor 20 is directly connected to the output unit 5.

[0046] As described above, the first forward mode is suitable for high-load driving, such as when starting with a heavy load on the vehicle, because the control unit 4 uses both the first electric motor 10 and the second electric motor 20.

[0047] Next, the second forward mode will be described. In the second forward mode, the control unit 4 drives only the first drive unit 1 and does not drive the second drive unit 2. Specifically, the control unit 4 rotates the first electric motor 10 in the first rotational direction and stops the second electric motor 20.

[0048] As a result, the torque of the first electric motor 10 is amplified by the first torque converter 11 and transmitted to the output unit 5.

[0049] This second forward mode is suitable for driving under medium loads, such as when starting with a light load on the vehicle, because the control unit 4 uses only the first electric motor 10, resulting in less load than the first forward mode.

[0050] Next, the third forward mode will be described. In the third forward mode, the control unit 4 drives only the second drive unit 2 and does not drive the first drive unit 1. Specifically, the control unit 4 rotates the second electric motor 20 in the first rotational direction and allows the first electric motor 10 to rotate freely.

[0051] As a result, the torque of the second electric motor 20 is transmitted to the output unit 5 via the second clutch 22. The torque of the second electric motor 20 is not amplified by the second torque converter 21. In other words, the second electric motor 20 is directly connected to the output unit 5.

[0052] As described above, the third forward mode is suitable for low-load driving, such as during steady-state driving, because the control unit 4 uses only the second electric motor 20 and the torque of the second electric motor 20 is not amplified.

[0053] Next, we will explain the braking modes during forward movement. First, we will explain the first braking mode. The control unit 4 is configured to execute the first braking mode and the second braking mode when moving forward and decelerating. In the first braking mode, the control unit 4 regenerates the first electric motor 10 and stops the second electric motor 20.

[0054] In detail, the control unit 4 makes the first electric motor 10 rotatable by the torque from the output unit 5. As a result, when the torque in the first rotational direction from the output unit 5 is transmitted to the first electric motor 10 via the first clutch 12, the first electric motor 10 rotates and the regenerative brake is activated.

[0055] Furthermore, in the second drive unit 2, the second clutch 22 does not transmit torque in the first rotational direction from the output unit 5. Also, since the second electric motor 20 is stopped, in the second torque converter 21, only the second turbine 212 rotates due to the torque in the first rotational direction from the output unit 5, and the second impeller 211 does not rotate.

[0056] Next, the second braking mode will be described. In the second braking mode, the control unit 4 regenerates the first electric motor 10 and rotates the second electric motor 20 in the second rotational direction. Specifically, the control unit 4 makes the first electric motor 10 rotatable by torque from the output unit 5. As a result, when torque in the first rotational direction from the output unit 5 is transmitted to the first electric motor 10 via the first clutch 12, the first electric motor 10 rotates and the regenerative brake is activated.

[0057] Furthermore, by having the control unit 4 rotate the second electric motor 20 in the second rotational direction, the second torque converter 21 can be used as a fluid retarder.

[0058] The second braking mode described above is suitable for situations where stronger braking force is required than in the first braking mode, such as when descending a slope with a heavy load on the vehicle.

[0059] Next, the operation of the control unit 4 during reverse movement will be described. During reverse movement, the control unit 4 executes the first reverse mode, the second reverse mode, the third reverse mode, and the third braking mode.

[0060] First, let's explain the first reverse mode. In the first reverse mode, the control unit 4 drives both the first drive unit 1 and the second drive unit 2 to move the vehicle in reverse. Specifically, the control unit 4 rotates the first electric motor 10 in the second rotational direction and also rotates the second electric motor 20 in the second rotational direction.

[0061] As a result, the torque of the first electric motor 10 is transmitted to the output unit 5 via the first clutch 12. The torque of the first electric motor 10 is not amplified by the first torque converter 11; that is, the first electric motor 10 is directly connected to the output unit 5. Furthermore, the torque of the second electric motor 20 is amplified by the second torque converter 21 before being transmitted to the output unit 5.

[0062] Next, the second reverse mode will be described. In the second reverse mode, the control unit 4 drives only the second drive unit 2 and does not drive the first drive unit 1. Specifically, the control unit 4 rotates the second electric motor in the second rotation direction and stops the first electric motor 10.

[0063] As a result, the torque of the second electric motor 20 is amplified by the second torque converter 21 and transmitted to the output unit 5. However, the torque in the second rotational direction from the output unit 5 is interrupted by the first clutch 12 and is not transmitted to the first electric motor 10.

[0064] Next, the third reverse mode will be explained. In the third reverse mode, the control unit 4 drives only the first drive unit 1 and does not drive the second drive unit 2. Specifically, the control unit 4 rotates the first electric motor 10 in the second rotation direction and allows the second electric motor 20 to rotate freely.

[0065] As a result, the torque of the first electric motor 10 is transmitted to the output unit 5 via the first clutch 12. The torque of the first electric motor 10 is not amplified by the first torque converter 11; that is, the first electric motor 10 is directly connected to the output unit 5. Furthermore, the torque in the second rotational direction from the output unit 5 is transmitted to the second electric motor 20 via the second clutch 22.

[0066] Next, the third braking mode, which is a braking mode during reverse movement, will be described. The control unit 4 is configured to execute the third braking mode when moving in reverse and decelerating. In the third braking mode, the control unit 4 stops the first electric motor 10 and regenerates power from the second electric motor 20.

[0067] In detail, the control unit 4 makes the second electric motor 20 rotatable by the torque from the output unit 5. As a result, the torque from the output unit 5 is transmitted to the second electric motor 20 via the second clutch 22, causing the second electric motor 20 to rotate and the regenerative brake to activate.

[0068] Furthermore, in the first drive unit 1, the first clutch 12 does not transmit torque in the second rotational direction from the output unit 5. Also, since the first electric motor 10 is stopped, in the first torque converter 11, only the first turbine 112 rotates due to the torque in the second rotational direction from the output unit 5, and the first impeller 111 does not rotate.

[0069] [Operation] In the drive unit 100 configured as described above, the control unit 4 executes either the first forward mode or the second forward mode when the vehicle starts moving. The driver can select either the first forward mode or the second forward mode.

[0070] The control unit 4 executes a third forward mode based on, for example, the vehicle speed. For example, when the vehicle speed reaches a first threshold, the control unit 4 switches from the first forward mode to the third forward mode. Also, when the vehicle speed reaches a second threshold, the control unit 4 switches from the second forward mode to the third forward mode. The second threshold is smaller than the first threshold.

[0071] When the vehicle is decelerating, the control unit 4 executes either a first braking mode or a second braking mode. For example, the control unit 4 executes the first braking mode based on the accelerator pedal position. Also, for example, after deceleration in the first braking mode, the control unit 4 switches from the first braking mode to the second braking mode by operation by the driver.

[0072] Similarly, when the vehicle is reversing, the control unit 4 selects and executes either the first reverse mode, the second reverse mode, or the third braking mode based on the driver's operation or driving conditions.

[0073] [Differentiation] Although embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications are possible without departing from the spirit of the invention. Furthermore, the following modifications can basically be applied simultaneously.

[0074] (a) In the above embodiment, the positional relationship between the electric motors 10, 20 and the torque converters 11, 21 is different in the first drive unit 1 and the second drive unit 2, but the arrangement of the components of the first drive unit 1 and the second drive unit 2 is not limited to this. The positional relationship between the electric motors 10, 20 and the torque converters 11, 21 may be the same in the first drive unit 1 and the second drive unit 2. For example, as shown in Figure 3, the first drive unit 1 is arranged in the order of the first electric motor 10 and the first torque converter 11 from the front of the vehicle (left side in Figure 3). The second drive unit 2 is arranged in the order of the second electric motor 20 and the second torque converter 21 from the front of the vehicle.

[0075] In this modified example, the first drive unit 1 and the second drive unit 2 are arranged along the width direction of the vehicle (vertical direction in Figure 3). The rotation axis O1 of the first drive unit 1 is located on a different axis from the rotation axis O2 of the second drive unit 2. Preferably, the rotation axis O1 of the first drive unit 1 extends substantially parallel to the rotation axis O2 of the second drive unit 2.

[0076] In this modified example, the power transmission mechanism 3 has a reversing gear 34. For example, the second gear train 32 has the reversing gear 34. Alternatively, the first gear train 31 may have the reversing gear 34 instead of the second gear train 32. Also, in this modified example, the first gear train 31 and the second gear train 32 do not have separate output gears 31b and 32b as in the above embodiment, but rather have a common output gear 33.

[0077] The reversing gear 34 is positioned between the second input gear 32a and the output gear 33. The reversing gear 34 meshes with the second input gear 32a and the output gear 33.

[0078] The gear ratio of the first gear train 31 is different from the gear ratio of the second gear train 32. For example, the gear ratio of the first gear train 31 is smaller than the gear ratio of the second gear train 32. However, the gear ratio of the first gear train 31 may be larger than the gear ratio of the second gear train 32. Also, the gear ratio of the first gear train 31 may be the same as the gear ratio of the second gear train 32.

[0079] In this modified configuration, when viewed from the front of the vehicle, the first rotation direction of the first electric motor 10 and the first rotation direction of the second electric motor 20 are different. Specifically, if the first rotation direction of the first electric motor 10 is clockwise when viewed from the left side of Figure 3, the first rotation direction of the second electric motor 20 is counterclockwise when viewed from the left side of Figure 3. Therefore, for example, if the vehicle is configured to move forward when the first electric motor 10 rotates clockwise, the vehicle will move forward when the second electric motor 20 rotates counterclockwise when viewed from the left side of Figure 3.

[0080] (b) In the above embodiment, the first clutch 12 and the second clutch 22 are configured as one-way clutches, but the configuration of the first clutch 12 and the second clutch 22 is not limited thereto. For example, the first clutch 12 and the second clutch 22 may be configured to be electronically controlled.

[0081] (c) In the above embodiment, the driver selected either the first forward mode or the second forward mode by operating the vehicle. However, the control unit 4 may select either the first forward mode or the second forward mode based on driving conditions or the like.

[0082] (d) In the above embodiment, the control unit 4 executed the third forward mode based on the vehicle speed, but the control unit 4 may also execute the third forward mode based on the driver's operation, or based on other driving conditions, etc.

[0083] (e) In the above embodiment, the control unit 4 executed the first braking mode based on the accelerator opening, but the first braking mode may also be executed based on the driver's operation, or based on other driving conditions, etc. Also, in the above embodiment, the control unit 4 switched from the first braking mode to the second braking mode based on the driver's operation, but the switching may also be performed based on driving conditions, etc. For example, after deceleration in the first braking mode, the control unit 4 may switch to the second braking mode when it determines that a predetermined speed has been reached. [Explanation of Symbols]

[0084] 1: First drive unit 10: First electric motor 11: First Torque Converter 12: First clutch 2: Second drive unit 20: Second electric motor 21: Second Torque Converter 22: Second clutch 3: Power transmission mechanism 34: Reversing gear 4: Control Unit 5: Output Unit

Claims

1. A drive unit for driving a vehicle forward and backward, a first drive unit including a first electric motor configured to rotate in a first rotational direction to move the vehicle forward and in a second rotational direction to move the vehicle backward, and a first torque converter configured to amplify the torque of the first electric motor in the first rotational direction; a second drive unit including a second electric motor configured to rotate in the first rotational direction and the second rotational direction, and a second torque converter configured to amplify the torque of the second electric motor in the second rotational direction; Equipped with Drive unit.

2. the first drive unit includes a first clutch configured to transmit torque of the first electric motor in the second rotational direction and to interrupt transmission of torque of the first electric motor in the first rotational direction.

2. The drive unit according to claim 1.

3. the second drive unit includes a second clutch configured to transmit torque of the second electric motor in the first rotational direction and to interrupt transmission of torque of the second electric motor in the second rotational direction.

3. A drive unit according to claim 1 or 2.

4. The first drive unit and the second drive unit have different positional relationships between the electric motors and the torque converters.

3. A drive unit according to claim 1 or 2.

5. The first drive unit and the second drive unit have the same positional relationship between the electric motors and the torque converters.

3. A drive unit according to claim 1 or 2.

6. a power transmission mechanism configured to transmit torque from the first drive unit and the second drive unit to an output unit; the power transmission mechanism has a reversing gear that reverses the rotation of the first electric motor or the second electric motor and outputs the reversed rotation to the output unit.

6. A drive unit according to claim 5.

7. a controller configured to control the first electric motor and the second electric motor; the control unit is configured to execute a first forward mode in which the first electric motor is rotated in the first rotational direction and the second electric motor is rotated in the first rotational direction.

2. The drive unit according to claim 1.

8. the control unit is configured to execute a second forward mode in which the first electric motor is rotated in the first rotational direction and the second electric motor is stopped.

8. A drive unit according to claim 7.

9. the control unit is configured to execute a third forward mode in which the first electric motor is rotated idly and the second electric motor is rotated in the first rotation direction.

8. A drive unit according to claim 7.

10. the control unit executes a first braking mode in which the first electric motor is regenerated and the second electric motor is stopped during forward movement and deceleration.

8. A drive unit according to claim 7.

11. the control unit executes a second braking mode in which, during forward movement and deceleration, the first electric motor is caused to regenerate and the second electric motor is caused to rotate in the second rotation direction.

8. A drive unit according to claim 7.

12. the control unit executes a first reverse mode in which the first electric motor is rotated in the second rotation direction and the second electric motor is rotated in the second rotation direction.

8. A drive unit according to claim 7.

13. the control unit executes a second reverse mode in which the first electric motor is stopped and the second electric motor is rotated in the second rotation direction.

8. A drive unit according to claim 7.

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