Drive unit

Abstract

To provide a drive system for vehicles. [Solution] The drive unit comprises a motor, a planetary gear mechanism, a differential gear, an output shaft, a case, an oil pump, and a transmission mechanism. The case houses the planetary gear mechanism and the differential gear. The oil pump circulates oil within the case. The oil pump is mechanically connected to the sun gear and is driven in conjunction with the rotation of the sun gear. The transmission mechanism can switch the operating mode of the planetary gear mechanism among several modes. In the first mode, relative rotation of the ring gear with respect to the case is prohibited, and relative rotation of the ring gear with respect to the carrier is permitted. In the second mode, relative rotation of the ring gear with respect to the carrier is prohibited, and relative rotation of the ring gear with respect to the case is permitted. In the neutral mode, relative rotation of the ring gear and carrier with respect to the case is permitted, and relative rotation between the ring gear and the carrier is permitted.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a drive device for a vehicle including a motor and a differential gear.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the drive device is left stationary for a long time, for example, oil film breakage may occur in the differential gear. Starting the differential gear in a state of oil film breakage may cause problems such as the gear seizure.

Means for Solving the Problems

[0005] The vehicle drive system disclosed herein comprises a motor. The drive system comprises a planetary gear mechanism having a sun gear, a ring gear, a carrier, and planetary gears. The driving force of the motor is transmitted to the sun gear. The drive system comprises a differential gear to which the driving force output from the planetary gear mechanism is transmitted. The drive system comprises an output shaft mechanically connected to the differential gear and outputting driving force to the outside. The drive system comprises a case housing the planetary gear mechanism and the differential gear. The drive system comprises an oil pump for circulating oil within the case. The oil pump is mechanically connected to the sun gear and is driven in conjunction with the rotation of the sun gear. The drive system comprises a speed control mechanism that can switch the operating mode of the planetary gear mechanism among several modes. The multiple modes include a first mode, a second mode, and a neutral mode. In the first mode, relative rotation of the ring gear with respect to the case is prohibited, while relative rotation of the ring gear with respect to the carrier is permitted. In the second mode, relative rotation of the ring gear with respect to the carrier is prohibited, while relative rotation of the ring gear with respect to the case is permitted. In the neutral mode, relative rotation of the ring gear and the carrier with respect to the case is permitted, as is relative rotation between the ring gear and the carrier.

[0006] In the above configuration, in the first mode, the carrier is rotatable around the central axis of the sun gear. Therefore, the motor's rotation is reduced by the planetary gear mechanism before being output to the output shaft. In the second mode, the carrier and ring gear rotate together with the sun gear. Therefore, the motor's rotation is not reduced by the planetary gear mechanism before being output to the output shaft. In the neutral mode, the carrier and ring gear are free. Therefore, the sun gear rotates freely, and the motor's driving force is not transmitted to the output shaft. In other words, the planetary gear mechanism can be switched between the first mode, where it functions as a reduction gear; the second mode, where it does not function as a reduction gear; and the neutral mode, where it does not transmit driving force to the output shaft. In the neutral mode, the oil pump can be driven by rotating the sun gear. By using the neutral mode, oil can be circulated within the case even when no driving force is output from the drive unit. Since oil can be supplied to the differential gear even when the vehicle is stationary, it is possible to prevent oil film breakdown when the vehicle is stationary. This makes it possible to prevent gear seizure and other issues during differential gear startup. [Brief explanation of the drawing]

[0007] [Figure 1] This is a skeleton diagram showing the schematic configuration of the drive unit 1. [Figure 2] This is an enlarged view of the vicinity of the planetary gear mechanism 30 to illustrate the first mode. [Figure 3] This is an enlarged view of the vicinity of the planetary gear mechanism 30 to explain the second mode. [Figure 4] This is an enlarged view of the vicinity of the planetary gear mechanism 30 to explain the neutral mode. [Figure 5] This is a flowchart explaining the control details of the transmission mechanism 40. [Modes for carrying out the invention]

[0008] The drive unit may further include a first shaft, which is arranged coaxially with the motor and driven by the motor. The drive unit may further include a second shaft, which is arranged parallel to the first shaft and to which the driving force of the first shaft is transmitted. A sun gear may be located at one end of the second shaft and an oil pump may be connected to the other end.

[0009] According to the above configuration, the oil pump and the sun gear can be mechanically connected by the second shaft.

[0010] The gear shifting mechanism may include a sleeve slidably positioned in the axial direction of the ring gear, and an actuator configured to move the sleeve between a first position, a second position, and a third position. The case may include a first ring portion coaxial with the ring gear. The carrier may include a second ring portion coaxial with the ring gear. Outer circumference splines may be formed on the outer circumference of the ring gear, the first ring portion, and the second ring portion. Inner circumference splines may be formed on the inner circumference of the sleeve, which engage with the outer circumference splines of the ring gear, the first ring portion, and the second ring portion. A first mode may be realized when the sleeve is in the first position, by engaging with the ring gear and the first ring portion but not with the second ring portion. A second mode may be realized when the sleeve is in the second position, by engaging with the ring gear and the second ring portion but not with the first ring portion. A neutral mode may be achieved when the sleeve is in the third position, by engaging with the ring gear but not with the first and second ring portions.

[0011] According to the above configuration, the operating mode of the planetary gear mechanism can be switched by the sleeve.

[0012] The drive system may further include a control unit that controls the operation of the transmission mechanism and the motor. The control unit may be configured to perform a pre-lubrication process that drives the motor with the operating mode set to neutral mode when the vehicle starts up.

[0013] With the above configuration, oil can be supplied to the differential gear through a pre-lubrication process when the vehicle starts up. This makes it possible to prevent gear seizure and other problems when the differential gear starts up.

[0014] The control unit may be configured to perform a step of switching the operating mode from the first or second mode to the neutral mode while the motor is stopped when the vehicle has finished starting up.

[0015] With the above configuration, the operating mode can be set to neutral mode when the vehicle is started up next time. This makes it possible to start the pre-lubrication process immediately. [Examples]

[0016] (Configuration of drive unit 1) Figure 1 is a skeleton diagram illustrating the structure of the drive unit 1 of an electric vehicle. The drive unit 1 is a device that drives a pair of left and right wheels (not shown) of the vehicle. The drive unit 1 may be an integrated device in which the motor, gear unit, and power conversion unit for controlling the motor are housed in the same casing. In Figure 1, the axial direction of the first shaft 61, second shaft 62, ring gear 32, third shaft 63, first output shaft 64, and second output shaft 65 is defined as the x-direction. The case 10 is shown in a cross-sectional view, and the components of the case 10 are hatched. The same applies to subsequent figures.

[0017] The drive unit 1 is controlled by the control unit 2. The control unit 2 includes a CPU, RAM, ROM, input / output interface, etc. The control unit 2 is connected to the motor 20, actuator 41, etc. by signal lines (not shown).

[0018] The drive device 1 mainly includes a case 10, a motor 20, a planetary gear mechanism 30, a speed change mechanism 40, an oil pump 50, a first shaft 61, a second shaft 62, a third shaft 63, a first output shaft 64, a second output shaft 65, and a differential gear 70.

[0019] The case 10 has a structure in which a motor cover 11, a center case 12, an intermediate case 13, and a gear cover 14 are arranged side by side in the x direction. Each of these cases may be a casting. The case 10 is formed by fastening these four members. The case 10 includes a first chamber R1, a second chamber R2, and a third chamber R3. The first chamber, the second chamber, and the third chamber are arranged in this order along the axial direction (i.e., the x direction) of the first shaft 61. The case 10 includes a first wall W1, a second wall W2, and a third wall W3. The first wall W1 separates the first chamber R1 and the second chamber R2. The second wall W2 separates the second chamber R2 and the third chamber R3. The third wall W3 defines the third chamber R3 between it and the second wall W2.

[0020] Bearings 81 and 82 are provided on the first wall W1. The bearing 81 rotatably supports the first shaft 61. The bearing 82 rotatably supports the second shaft 62. Bearings 83, 84, and 85 are provided on the second wall W2. The bearing 83 rotatably supports the first shaft 61. The bearing 84 rotatably supports the third shaft 63. The bearing 85 rotatably supports the first output shaft 64. Bearings 86 and 87 are provided on the third wall W3. The bearing 86 rotatably supports the third shaft 63. The bearing 87 rotatably supports the second output shaft 65.

[0021] The effects will be described. The first wall W1, the second wall W2, and the third wall W3 are provided with various bearings. As a result, three assemblies, namely the assembly having the first wall W1, the assembly having the second wall W2, and the assembly having the third wall W3, can be pre-assembled. And in the final assembly process, these three assemblies can be assembled. It becomes possible to simplify the assembly process of the drive device 1.

[0022] In the first chamber R1, the motor 20 and the oil pump 50 are mainly stored. The motor 20 includes a stator 21, a rotor 22, and a motor shaft 23. The stator 21 has a cylindrical shape. Inside the stator 21, the rotor 22 is rotatably arranged. The motor shaft 23 is fixed to the rotor 22.

[0023] In the second chamber R2, the first shaft 61, the second shaft 62, the first gear pair 91, a part of the planetary gear mechanism 30, and a part of the transmission mechanism 40 are mainly stored. The first shaft 61 is coaxially connected to the motor shaft 23. The first shaft and the motor shaft 23 have a hollow structure. The first shaft 61 is supported by bearings 81 and 83. The first shaft 61 is driven by the motor 20.

[0024] The second shaft 62 is arranged parallel to the first shaft 61. The second shaft 62 is supported by bearings 82 and 89. The first shaft 61 and the second shaft 62 are coupled by the first gear pair 91. The driving force of the first shaft 61 is transmitted to the second shaft 62.

[0025] The planetary gear mechanism 30 includes a sun gear 31, a ring gear 32, a planetary gear 33, and a carrier 34. The sun gear 31 is arranged at the +x direction end of the second shaft 62. The sun gear 31 is mechanically connected to the motor shaft 23 via the first gear pair 91 and the first shaft 61. As a result, the planetary gear mechanism 30 has the sun gear 31 as the input and the carrier 34 as the output.

[0026] The -x end of the second shaft 62 is connected to the oil pump 50. This mechanically connects the oil pump 50 to the sun gear 31. The oil pump 50 is responsible for circulating oil within the case 10. The oil pump 50 is a mechanical pump and is driven in conjunction with the rotation of the sun gear 31. This allows the amount of oil circulated to increase in conjunction with the increase in the rotational speed of the sun gear 31. This effectively prevents seizure and wear in the various gears within the case 10.

[0027] Chamber R3 mainly houses the third shaft 63, the second gear pair 92, the differential gear 70, the first output shaft 64, the second output shaft 65, and part of the transmission mechanism 40. The third shaft 63 is arranged coaxially with the second shaft 62. The third shaft 63 is supported by bearings 84 and 86. The -x end of the third shaft 63 is connected to the carrier 34. The driving force output from the planetary gear mechanism 30 is transmitted to the third shaft 63. The third shaft 63 is coupled to the differential gear 70 by the second gear pair 92. The second gear pair 92 is a gear pair consisting of a parallel gear located on the third shaft 63 and a ring gear provided on the differential gear 70.

[0028] The differential gear 70 is a mechanism that distributes the driving force transmitted from the third shaft 63 to a pair of left and right first output shafts 64 and second output shafts 65. The first output shafts 64 and second output shafts 65 are arranged coaxially with each other. The first output shafts 64 and second output shafts 65 are shafts for outputting driving force to a pair of tires (not shown).

[0029] The first output shaft 64 is supported by bearings 85 and 88. The +x end of the first output shaft 64 is connected to the differential gear 70. The -x end of the first output shaft 64 passes through the first shaft 61. This reduces the space required for arranging the first output shaft 64, thereby enabling a smaller overall size for the drive unit 1.

[0030] The second output shaft 65 is supported by a bearing 87. The -x end of the second output shaft 65 is connected to the differential gear 70.

[0031] (Configuration of the transmission mechanism 40) The transmission mechanism 40 mainly comprises an actuator 41, a ball screw 42, a biasing unit 43, a shift fork 44, a sleeve 45, a first ring portion 46, a second ring portion 47, and a ring gear hub 48. The first ring portion 46 is located coaxially with the ring gear 32 and is positioned on the second wall W2. The second ring portion 47 is located coaxially with the ring gear 32 and is positioned on the carrier 34. The ring gear hub 48 is located coaxially with the ring gear 32 and is fixed to the outer circumference of the ring gear 32. Outer circumference splines are formed on the outer circumferences of the first ring portion 46, the second ring portion 47, and the ring gear hub 48. The sleeve 45 is slidably positioned in the axial direction (i.e., x-direction) of the ring gear 32. An inner circumference spline is formed on the inner circumference of the sleeve 45. The inner circumferential splines are configured to engage with the outer circumferential splines of the first ring portion 46, the second ring portion 47, and the ring gear hub 48.

[0032] Actuator 41 is a rotary actuator. In this embodiment, actuator 41 is a motor. Ball screw 42 is a linear motion mechanism that converts the rotational motion output by actuator 41 into linear motion. The nut 42n of ball screw 42 is connected to shift fork 44 via biasing part 43. The -x end of shift fork 44 is connected to sleeve 45. Shift fork 44 is a component that transmits the linear motion output by ball screw 42 to sleeve 45. Shift fork 44 is configured to be movable in a first direction D1 and a second direction D2 in the axial direction of ring gear 32. The first direction D1 is the direction away from ring gear 32 (i.e., the +x direction). The second direction D2 is the direction towards ring gear 32 (i.e., the -x direction).

[0033] The biasing unit 43 is equipped with a spring (not shown) and applies an axial biasing force of the ring gear to the shift fork 44. When the shift fork moves in the first direction D1, the biasing unit 43 applies a biasing force in the first direction D1 to the shift fork 44. Furthermore, when the shift fork moves in the second direction D2, the biasing unit 43 applies a biasing force in the second direction D2 to the shift fork 44. The specific structure for realizing the function of the biasing unit 43 is well known, so a detailed explanation is omitted.

[0034] (Operation of the gear shift mechanism 40) The gear shifting mechanism 40 is a mechanism that can switch the operating mode of the planetary gear mechanism 30 between a first mode, a second mode, and a neutral mode. In the first mode, the rotation of the motor 20 is reduced before being transmitted to the output shaft. In the second mode, the rotation of the motor 20 is transmitted to the output shaft without reduction. In the neutral mode, the driving force of the motor 20 is not transmitted to the output shaft. Switching between operating modes is performed by moving the sleeve 45 between the first position P1, the second position P2, and the third position P3. This will be explained below.

[0035] The first mode will be explained using Figure 2. Figure 2 is an enlarged view of the vicinity of the planetary gear mechanism 30. In the first mode, the sleeve 45 is in the first position P1. In the first position P1, the sleeve 45 is engaged with the ring gear hub 48 and the first ring portion 46, but not with the second ring portion 47. The ring gear 32 is coupled to the case 10 in a way that prevents relative rotation, and the ring gear 32 is discoupled from the carrier 34. That is, in the first mode, relative rotation of the ring gear 32 with respect to the case 10 is prohibited, while relative rotation of the ring gear 32 with respect to the carrier 34 is permitted. Therefore, the carrier 34 is rotatable around the central axis of the sun gear 31. Thus, the rotation of the first shaft 61 is transmitted to the carrier 34 via the sun gear 31 and the planetary gear 33. The rotation of the first shaft 61 is also transmitted to the oil pump 50 via the second shaft 62 (see the transmission path T1 shown by the dotted arrow). As a result, the planetary gear mechanism 30 functions as a reduction gear.

[0036] The second mode will be explained using Figure 3. Figure 3 is an enlarged view of the vicinity of the planetary gear mechanism 30. In the second mode, the sleeve 45 is in the second position P2. In the second position P2, the sleeve 45 is engaged with the ring gear hub 48 and the second ring portion 47, but not with the first ring portion 46. The ring gear 32 is connected to the carrier 34 in a way that prevents relative rotation, and the ring gear 32 is disconnected from the case 10. In other words, in the second mode, relative rotation of the ring gear 32 with respect to the carrier 34 is prohibited, while relative rotation of the ring gear 32 with respect to the case 10 is permitted. Therefore, the carrier 34 and the ring gear 32 rotate together with the sun gear 31. Thus, the rotation of the first shaft 61 is transmitted to the carrier 34 via the sun gear 31, planetary gear 33, ring gear 32, ring gear hub 48, sleeve 45, and second ring portion 47. Furthermore, the rotation of the first shaft 61 is transmitted to the oil pump 50 via the second shaft 62 (see transmission path T2 indicated by the dotted arrow). As a result, the planetary gear mechanism 30 does not function as a reduction gear.

[0037] The neutral mode will be explained using Figure 4. Figure 4 is an enlarged view of the vicinity of the planetary gear mechanism 30. In the neutral mode, the sleeve 45 is in the third position P3. In the third position P3, the sleeve 45 is engaged with the ring gear hub 48, but not with the first ring portion 46 and the second ring portion 47. The ring gear 32 and the carrier 34 are disengaged from the case 10. That is, in the neutral mode, relative rotation of the ring gear 32 and the carrier 34 with respect to the case 10 is permitted, as is relative rotation between the ring gear 32 and the carrier 34. Therefore, the carrier 34 and the ring gear 32 are free. Thus, the rotation of the first shaft 61 is transmitted to the sun gear 31, and the sun gear 31 rotates freely. The rotation of the first shaft 61 is also transmitted to the oil pump 50 via the second shaft 62 (see the transmission path T3 shown by the dotted arrow). As a result, no driving force is output from the planetary gear mechanism 30.

[0038] (Control flow of the transmission mechanism 40) The control of the transmission mechanism 40 will be explained using the flowchart in Figure 5. The control in Figure 5 is constantly performed by the control device 2. In step S10, the control device 2 determines whether or not the vehicle's control system has been started. This determination may also be made by determining whether or not the ignition switch has been turned on. If the system has not been started (S10: NO), the device waits; if it has been started (S10: YES), the device proceeds to S20.

[0039] In step S20, the control device 2 performs a pre-lubrication process. This will be explained in detail. When the vehicle's control system is started up, the operating mode of the planetary gear mechanism 30 is set to neutral mode. The control device 2 then drives the motor 20 in neutral mode. This allows the oil pump 50 to be driven while the vehicle is stationary. Oil can be supplied to the planetary gear mechanism 30 and the differential gear 70.

[0040] In step S30, the control device 2 stops the motor 20. This completes the pre-lubrication process. The duration for which the motor 20 is driven may be predetermined, or it may be adjusted as appropriate depending on the ambient temperature, the time elapsed since the last stop, etc.

[0041] In step S40, the control device 2 switches the operating mode of the planetary gear mechanism 30 to either the first mode or the second mode. This mechanically connects the motor 20 to the output shaft. The process then proceeds to step S50, where the vehicle enters a waiting state for operation.

[0042] In step S60, the control device 2 drives the vehicle according to the user's operation. The planetary gear mechanism 30 operates in a first mode in areas where driving force is required, and in a second mode in normal driving areas where high driving force is not required.

[0043] In step S70, the control device 2 determines whether or not a start / stop command for the vehicle's control system has been input. This determination may also be made based on whether or not the ignition switch has been turned off. If no start / stop command has been input (S70: NO), the device waits; if it has been input (S70: YES), the device proceeds to S80.

[0044] In step S80, with the motor 20 stopped, the control device 2 switches the operating mode of the planetary gear mechanism 30 from the first or second mode to the neutral mode. This mechanically disconnects the motor 20 from the output shaft. In step S90, the vehicle control system is terminated. Then the process returns to step S10.

[0045] According to this control system, after the switch to neutral mode (S80) is executed, the vehicle's control system is terminated (S90). Therefore, at the next time the vehicle is started (S10:YES), the operating mode can be set to neutral mode. This makes it possible to start the pre-lubrication process (S20) immediately.

[0046] (effect) If the drive unit 1 is left stationary for a long period of time, the oil film in the differential gear 70 may break down. If the differential gear 70 is started in a state of oil film breakdown, problems such as gear seizure may occur. In the technology described herein, the planetary gear mechanism 30 can be switched between a first mode in which it functions as a reduction gear, a second mode in which it does not function as a reduction gear, and a neutral mode in which it does not transmit driving force to the output shaft. In the neutral mode, the oil pump 50 can be driven by rotating the sun gear 31. By using the neutral mode, oil can be supplied to the differential gear 70 even when the vehicle is stationary, thus preventing oil film breakdown when the vehicle is stationary. This makes it possible to prevent gear seizure and other problems when starting the differential gear 70.

[0047] When the drive unit 1 is stationary, if oil adheres to the rotor 22 of the motor 20, it will create stirring resistance in the rotor 22 during operation, resulting in significant energy loss. This is because the gap between the outer circumference of the rotor 22 and the inner circumference of the stator 21 is small. In addition, the oil will foam, causing oil leakage. Therefore, it is necessary to reduce the amount of oil filled in the case 10 (i.e., lower the stationary oil level) so that oil does not adhere to the rotor 22 when stationary. In this embodiment, where the motor shaft 23 and the differential gear 70 are coaxial, if the stationary oil level is lowered to the extent that oil does not adhere to the rotor 22, oil will also not adhere to the differential gear 70. Therefore, in the technology described herein, by performing a pre-lubrication process (S20) when the vehicle starts up, oil can be supplied to the differential gear 70. This makes it possible to prevent seizure of the differential gear 70 during startup while suppressing energy loss and oil foaming.

[0048] When driving on inclines or other situations where driving force is infrequent, the frequency of switching between the first and second modes in the planetary gear mechanism 30 decreases. In this case, the meshing phase between the inner splines of the sleeve 45 and the outer splines of the first ring portion 46, the second ring portion 47, and the ring gear hub 48 does not change, which may cause uneven wear of the spline teeth. Therefore, in the technology described herein, oil can be supplied to the planetary gear mechanism 30 by performing a pre-lubrication step (S20) when the vehicle starts up. This makes it possible to suppress uneven wear of the spline teeth.

[0049] Although embodiments have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself.

[0050] (modified version) The configuration of the drive unit 1 can vary. For example, the first output shaft 64 may be arranged parallel to the motor shaft 23 and the first shaft 61. Alternatively, the first shaft 61, the planetary gear mechanism 30, and the differential gear 70 may be arranged coaxially. In this configuration, the second shaft 62 and the third shaft 63 can be omitted, allowing for further miniaturization of the unit.

[0051] The drive unit 1 may be configured to include only one of the first output shaft 64 and the second output shaft 65. In this case, the differential gear 70 can be omitted.

[0052] The vehicles to which the drive system described herein is installed are not limited to electric vehicles. The drive system described herein can be installed in, for example, hybrid vehicles and plug-in hybrid vehicles. Furthermore, the drive system described herein is also applicable to vehicles that use an electric motor for at least part of their driving, such as fuel cell vehicles. [Explanation of symbols]

[0053] 1: Drive unit 10: Case 20: Motor 30: Planetary gear mechanism 31: Sun gear 32: Ring gear 33: Planetary gear 34: Carrier 40: Speed ​​change mechanism 41: Actuator 45: Sleeve 50: Oil pump 61: First shaft 62: Second shaft 64: First output shaft 65: Second output shaft

Claims

1. A drive system for a vehicle, Motor and, A planetary gear mechanism having a sun gear, a ring gear, a carrier, and planetary gears, wherein the driving force of the motor is transmitted to the sun gear, A differential gear to which the driving force output from the planetary gear mechanism is transmitted, An output shaft is mechanically connected to the differential gear and outputs driving force to the outside, A case housing the planetary gear mechanism and the differential gear, An oil pump for circulating oil within the case, which is mechanically connected to the sun gear and driven in conjunction with the rotation of the sun gear, A variable speed mechanism that can switch between multiple operating modes of the planetary gear mechanism, Equipped with, The aforementioned multiple modes are, A first mode in which the relative rotation of the ring gear with respect to the case is prohibited, and the relative rotation of the ring gear with respect to the carrier is permitted, A second mode in which the relative rotation of the ring gear with respect to the carrier is prohibited, and the relative rotation of the ring gear with respect to the case is permitted, A neutral mode is permitted in which the relative rotation of the ring gear and the carrier with respect to the case is allowed, and relative rotation between the ring gear and the carrier is allowed. A drive system, including a drive mechanism.

2. A first shaft is arranged coaxially with the motor and driven by the motor, A second shaft is arranged parallel to the first shaft and to which the driving force of the first shaft is transmitted, Furthermore, The drive device according to claim 1, wherein the sun gear is located at one end of the second shaft and the oil pump is connected to the other end.

3. The aforementioned transmission mechanism is A sleeve is slidably positioned in the axial direction of the ring gear, An actuator configured to move the sleeve between a first position, a second position, and a third position, It is equipped with, The case is equipped with a first ring portion located coaxially with the ring gear, The carrier is equipped with a second ring portion located coaxially with the ring gear, Outer circumference splines are formed on the outer circumference of the ring gear, the first ring portion, and the second ring portion. An inner spline is formed on the inner circumference of the sleeve, which engages with the outer splines of the ring gear, the first ring portion, and the second ring portion. When the sleeve is in the first position, the first mode is realized by the sleeve engaging with the ring gear and the first ring portion but not with the second ring portion. When the sleeve is in the second position, the second mode is realized by the sleeve engaging with the ring gear and the second ring portion but not with the first ring portion. The drive device according to claim 1, wherein when the sleeve is in the third position, the neutral mode is achieved by the sleeve engaging with the ring gear and not engaging with the first ring portion and the second ring portion.

4. The system further comprises a control unit that controls the operation of the gear shift mechanism and the motor, The drive device according to claim 1, wherein the control unit is configured to perform a pre-lubrication step in which the motor is driven with the operating mode set to the neutral mode when the vehicle starts up.

5. The drive device according to claim 4, wherein the control unit is configured to perform the step of switching the operating mode from the first mode or the second mode to the neutral mode while the motor is stopped when the vehicle has finished starting up.

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