Drive device and vehicle

Abstract

This drive device comprises a first torque transmission path and a second torque transmission path and is capable of alternatively transmitting torque from a drive source to an object to be driven via the first torque transmission path or the second torque transmission path. When a sun gear is driven by the drive source to rotate to one side in the circumferential direction, a first clutch unit is engaged and a second clutch unit is disengaged, whereby torque is transmitted to the object to be driven via the first torque transmission path, and the object to be driven rotates to the other side in the circumferential direction. When the sun gear is driven by the drive source to rotate to the other side in the circumferential direction, the first clutch unit is disengaged and the second clutch unit is engaged, and torque is transmitted to the object to be driven via the second torque transmission path and the object to be driven rotates to the other side in the circumferential direction. When the object to be driven rotates to the one side in the circumferential direction, the second clutch unit is disengaged.

Description

Drive unit and vehicle

[0001] The present invention relates to a drive unit and a vehicle equipped with the drive unit.

[0002] In recent years, with the implementation of the "double carbon" strategy, the new energy field has been developing rapidly. New energy vehicles are increasingly popular with consumers due to their convenience, environmental friendliness, and low cost. In the field of vehicles, especially in the field of electric vehicles such as electric bicycles and electric motorcycles, power is sometimes transmitted using a planetary gear mechanism as a transmission mechanism. Vehicles have different requirements for rotational speed and torque in different situations. For example, low rotational speed and high torque are required when starting, but high rotational speed and low torque are required when the vehicle is traveling at high speed.

[0003] To this end, we provide a vehicle equipped with a two-speed drive system that achieves two-speed drive using two one-way clutch units. In this drive system, a sun gear serves as an input component and is connected to a motor rotor, a stator of the motor is fixedly attached to a stator shaft, the rotor generates mechanical energy to perform work, and the internal gear serves as an output component and can transmit torque to the drive wheels. The planet carrier can be locked to the stator shaft by a first one-way clutch and to the internal gear by a second clutch unit. When the sun gear is driven in one direction, the second clutch unit is disengaged and the first clutch unit is engaged, preventing the planet carrier from rotating and allowing the internal gear to rotate at a low speed. When the sun gear is driven in the other direction, the first clutch unit is disengaged and the second clutch unit is engaged, allowing the sun gear, planet gear, and internal gear to rotate together. This allows the drive system to achieve two-speed drive for the vehicle.

[0004] However, when a vehicle equipped with this mechanism is manually pushed backward, the wheels rotate in the opposite direction, and both the first clutch unit and the second clutch unit are engaged, locking the drive wheels relative to the stator shaft and preventing them from rotating. Therefore, such a vehicle cannot be pushed backward manually.

[0005] The present invention has been made in view of the above circumstances, and has an object to prevent the drive unit from locking when a vehicle including the drive unit is pushed backward by human power.

[0006] In order to achieve the above object, the present invention uses the following technical means.

[0007] According to one aspect of the present invention, a drive device that transmits torque from a drive source to a driven object includes a planetary gear mechanism, a first clutch unit, a second clutch unit, and a housing, the housing is fixedly connected to the driven object, the planetary gear mechanism includes an internal gear, a sun gear, a planet carrier, and planet gears, the drive device has a first torque transmission path and a second torque transmission path, and is capable of transmitting torque from the drive source to the driven object alternatively via the first torque transmission path or the second torque transmission path, the sun gear is driven by the drive source and rotates on one side in the circumferential direction When the sun gear rotates in the circumferential direction, the first clutch unit is engaged and the second clutch unit is disengaged, thereby transmitting torque to the driven object via the first torque transmission path, causing the driven object to rotate in the other circumferential direction; when the sun gear is driven by the driving source to rotate in the other circumferential direction, the first clutch unit is disengaged and the second clutch unit is engaged, thereby transmitting torque to the driven object via the second torque transmission path, causing the driven object to rotate in the other circumferential direction; when the sun gear rotates in the circumferential direction, the second clutch unit is disengaged.

[0008] According to one aspect of the present invention, two-speed shifting can be achieved even in a drive unit including a single planetary gear mechanism. Furthermore, when a vehicle is pushed or pulled backward by human power or the like, locking of the drive wheels can be avoided and the drive wheels can be rotated backward, allowing the vehicle to move backward smoothly.

[0009] FIG. 1 is a cross-sectional schematic diagram showing a drive unit according to an embodiment of the present invention. FIG. 2 is a topology schematic diagram when the drive unit is in first gear. FIG. 3 is a topology schematic diagram when the drive unit is in second gear. FIG. 4 is a topology schematic diagram when the drive unit stops driving and the vehicle is manually pushed forward. FIG. 5 is a topology schematic diagram when the drive unit stops driving and the vehicle is manually pushed backward. FIG. 6A is a schematic diagram showing the state of the second clutch unit when the drive unit is in first gear. FIG. 6B is a schematic diagram showing the state of the second clutch unit when the drive unit is in first gear. FIG. 7A is a schematic diagram showing the state of the second clutch unit when the drive unit is in second gear. FIG. 7B is a schematic diagram showing the state of the second clutch unit when the drive unit is in second gear. FIG. 8A is a schematic diagram showing the state of the second clutch unit when the drive unit stops driving and the vehicle is manually pushed backward. Fig. 8B is a schematic diagram showing the state of the second clutch unit when the drive device stops driving and the vehicle is pushed backward by human power. Fig. 9 is a schematic cross-sectional view showing a drive device according to another embodiment of the present invention. Fig. 10A is a schematic diagram showing the state of the second clutch unit when the drive device is in first gear or when the drive device stops driving and the vehicle is pushed backward by human power. Fig. 10B is a schematic diagram showing the state of the second clutch unit when the drive device is in first gear or when the drive device stops driving and the vehicle is pushed backward by human power. Fig. 11A is a schematic diagram showing the state of the second clutch unit when the drive device is in second gear. Fig. 11B is a schematic diagram showing the state of the second clutch unit when the drive device is in second gear.

[0010] Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. It should be understood that these specific descriptions are merely intended to teach those skilled in the art how to implement the present invention, and do not encompass all possible forms of the present invention or limit the scope of the present invention.

[0011] In this specification, "axial direction," "radial direction," and "circumferential direction" refer to the axial direction, radial direction, and circumferential direction of the motor M, respectively. "Fixed connection" means that two members are connected so that there is no relative movement, and unless otherwise specified, includes both a direct fixed connection and an indirect fixed connection via another member. "Lock" includes both a direct lock and an indirect lock via another member. "Power transmission connection" means that two members are connected so that torque can be transmitted.

[0012] As used herein, "rotational speed" may refer to the number of times a rotating object rotates around its central axis within a unit of time (number of rotations), and its unit may be, for example, rpm (revolutions per minute). "Speed" may refer to the ratio of displacement traveled by a moving object to time, and its unit may be, for example, m / s, km / h, etc.

[0013] (Driver) Hereinafter, a drive device 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 8B.

[0014] Figure 1 shows a two-speed drive unit 1 of this embodiment, which includes a motor M as a drive source, a planetary gear mechanism 20, a first clutch unit 30, a second clutch unit 40, and a housing 50.

[0015] The motor M includes a stator S, a rotor R, and a stator shaft O. The stator S is fixed to the stator shaft O. The stator shaft O extends linearly in the axial direction and is fixed to a vehicle to which the motor M is to be attached. The rotor R is fixed to a rotor holder 10 and is disposed radially outward of the stator S. The rotor R is provided coaxially with the stator S and is rotatable relative to the stator S.

[0016] The planetary gear mechanism 20 includes an internal gear 201, a sun gear 202, a planet carrier 203, and planet gears 204. The sun gear 202 can receive torque input from the motor M. The internal gear 201 is connected to a driving wheel T, which is a drive target of the vehicle, and outputs torque to the driving wheel T. More specifically, the housing 50 is fixedly connected to the driving wheel T, and the internal gear 201 is connected to the housing 50. The multiple planet gears 204 are held by the planet carrier 203. The multiple planet gears 204 are positioned radially between the internal gear 201 and the sun gear 202, and mesh with the internal gear 201 and the sun gear 202, respectively. The vehicle runs by transmitting the rotation of the internal gear 201 to the driving wheel T.

[0017] In this embodiment, the drive unit 1 has a first torque transmission path and a second torque transmission path. Torque from the motor M is transmitted between the internal gear 201, the planet carrier 203, and the sun gear 202, alternatively via the first torque transmission path or the second torque transmission path.

[0018] The first clutch unit 30 has an inner ring and an outer ring. In the engaged state of the first clutch unit 30, the inner ring and the outer ring cannot rotate relative to each other. In the disengaged state of the first clutch unit 30, the inner ring and the outer ring can rotate relative to each other. Preferably, the inner ring is fixedly attached to the stator shaft O, and the planetary carrier 203 functions as the outer ring of the first clutch unit 30. The first clutch unit 30 is a one-way clutch. In this embodiment, a one-way clutch is a clutch in which, when one of the outer ring and the inner ring of the clutch rotates in one direction relative to the other, the clutch is in a disengaged state and the outer ring and the inner ring cannot transmit torque, and when one of the outer ring and the inner ring rotates in the other direction relative to the other, the clutch switches to an engaged state and the outer ring and the inner ring are coupled to transmit torque. Typical one-way clutches include various well-known one-way clutches, such as a sprag-type one-way clutch, a ratchet wheel-ratchet pawl-type one-way clutch, and a roller-type one-way clutch.

[0019] The second clutch unit 40 has an inner ring 401 and an outer ring 402, and the outer ring 402 is fixed to the housing 50. In an engaged state, the inner ring 401 and the outer ring 402 cannot rotate relative to each other, and in a disengaged state, the inner ring 401 and the outer ring 402 can rotate relative to each other. The planet carrier 203 is fixed to the inner ring 401 of the second clutch unit 40, or functions as the inner ring 401 of the second clutch unit 40. The second clutch unit 40 is a selectable one-way clutch. In this embodiment, a controllable one-way clutch is a clutch in which, when one of the outer and inner rings of the clutch rotates in one direction relative to the other, the clutch is in a disengaged state and the outer and inner rings are unable to transmit torque, and when one of the outer and inner rings rotates in the other direction relative to the other, the clutch can be controllably selected to be in an engaged or disengaged state, and when the clutch is in an engaged state, the outer and inner rings are engaged and are able to transmit torque, and when the clutch is in a disengaged state, the outer and inner rings are separated and are unable to transmit torque.

[0020] In this embodiment, when the motor M rotates in one circumferential direction, the first clutch unit 30 is engaged and the second clutch unit 40 is disengaged. When the motor M rotates in the other circumferential direction, the first clutch unit 30 is disengaged and the second clutch unit 40 is engaged. When the first clutch unit 30 is in an engaged state, the planet carrier 203 is locked to the stator shaft O by the first clutch unit 30, and can be locked to the stator S. When the second clutch unit 40 is in an engaged state, the planet carrier 203 can be power-transmittingly connected to the internal gear 201 by the second clutch unit 40. At different gears, the first clutch unit 30 or the second clutch unit 40 can be selectively engaged.

[0021] The second clutch unit 40 is located radially outward from the first clutch unit 30. An inner ring of the first clutch unit 30 is fixed to the stator shaft O of the motor M. An outer ring 402 of the second clutch unit 40 is fixed to the housing 50 and, in turn, to the drive wheels T. The second clutch unit 40 is located between the planet carrier 203 and the housing 50 in the second torque transmission path. When the motor M rotates in one circumferential direction, the second clutch unit 40 is disengaged, and when the motor M rotates in the other circumferential direction, the second clutch unit 40 is engaged.

[0022] In this embodiment, the drive unit 1 can satisfy the following operating modes: when the sun gear 202 is driven by the motor M to rotate in one circumferential direction, the first clutch unit 30 is engaged and the second clutch unit 40 is disengaged, thereby transmitting torque to the drive wheel T via the first torque transmission path and causing the drive wheel T to rotate in the other circumferential direction; when the sun gear 202 is driven by the motor M to rotate in the other circumferential direction, the first clutch unit 30 is disengaged and the second clutch unit 40 is engaged, thereby transmitting torque to the drive wheel T via the second torque transmission path and causing the drive wheel T to rotate in the other circumferential direction; and when the motor M stops driving and the vehicle including the drive unit 1 is manually pushed backward, the drive wheel T rotates in one circumferential direction and the second clutch unit 40 is disengaged.

[0023] Specifically, as shown in FIG. 2 , when the drive unit 1 is in first gear, the vehicle moves forward. The sun gear 202 is driven by the motor M toward one side in the circumferential direction, the second clutch unit 40 is disengaged, and the first clutch unit 30 is engaged. This prevents the planetary carrier 203 from rotating, and the planetary gears 204 rotate on their axes without revolving. Torque from the motor M is transmitted from the sun gear 202 to the internal gear 201 via the first torque transmission path. As a result, the internal gear 201 outputs a torque reduced relative to the sun gear 202, and the internal gear 201 rotates toward the other side in the circumferential direction at a preset reduction ratio (transmission ratio), for example, 2.95. In other words, the rotational speed of the sun gear 202 as the input component is 2.95 times the rotational speed of the internal gear 201 as the output component, allowing the vehicle to move forward at a relatively low speed.

[0024] As shown in FIG. 3 , when the drive unit 1 is in second gear, the vehicle moves forward. The sun gear 202 is driven by the motor M toward the other side in the circumferential direction, the first clutch unit 30 is disengaged, and the second clutch unit 40 is engaged. As a result, the planetary carrier 203 and the internal gear 201 rotate together, the planetary gear 204 revolves without rotating, and the sun gear 202, planetary gear 204, planetary carrier 203, and internal gear 201 rotate together toward the other side in the circumferential direction. Torque from the motor M is transmitted from the sun gear 202 to the internal gear 201 via the second torque transmission path. At this time, the reduction ratio (transmission ratio) is 1, and the internal gear 201 outputs torque at a constant speed relative to the sun gear 202. That is, the rotational speed of the sun gear 202 as an input component is the same as the rotational speed of the planetary carrier 203 and the internal gear 201 as output components, and the vehicle can move forward at a relatively high speed.

[0025] As shown in Figure 4, when the drive unit 1 stops driving and the vehicle is pushed forward by human power, the drive of the motor M is stopped, but the internal gear 201 rotates toward the other side in the circumferential direction. At this time, the first clutch unit 30 is in a disengaged state, and the second clutch unit 40 is in a disengaged state. Therefore, the internal gear 201 and the stator shaft O are not fixed to each other. Torque generated by human power is transmitted from the internal gear 201 to the sun gear 202 via the first torque transmission path.

[0026] As shown in Figure 5, when the drive unit 1 stops driving and the vehicle is pushed backward by human power, the motor M stops driving, but the internal gear 201 rotates toward one side in the circumferential direction. At this time, the first clutch unit 30 is in an engaged state, and the second clutch unit 40 is in a disengaged state. Therefore, the internal gear 201 and the stator shaft O are not fixed to each other. Torque generated by human power is transmitted from the internal gear 201 to the sun gear 202 via the first torque transmission path.

[0027] The specific structure of the second clutch unit 40 will be described below with reference to Fig. 1 and Figs. 6A to 8B. Fig. 6A is a schematic diagram showing the state of the second clutch unit 40 when the drive device 1 is in first gear, and is a schematic cross-sectional view of portion A in Fig. 1 as viewed from the axial direction. Fig. 6B is a schematic cross-sectional view of portion B in Fig. 1 as viewed from the axial direction. Fig. 7A is a schematic diagram showing the state of the second clutch unit 40 when the drive device 1 is in second gear, and is a schematic cross-sectional view of portion A in Fig. 1 as viewed from the axial direction. Fig. 7B is a schematic cross-sectional view of portion B in Fig. 1 as viewed from the axial direction. Fig. 8A is a schematic diagram showing the state of the second clutch unit 40 when the drive device 1 stops driving and the vehicle is pushed backward by human power, and is a schematic cross-sectional view of portion A in Fig. 1 as viewed from the axial direction. Fig. 8B is a schematic cross-sectional view of portion B in Fig. 1 as viewed from the axial direction.

[0028] The second clutch unit 40 includes an inner ring 401, an outer ring 402 disposed radially outward of the inner ring 401, a fixed ring 403 that cannot rotate relative to the outer ring 402, a plurality of sprags 405 disposed between the inner ring 401 and the outer ring 402 and held by the fixed ring 403 as a coupling portion whose position is adjustable (pivotable), and an operating member 404 such as a control ring that controls the position of the sprags 405. When the sprags 405 are in an upright position (see FIG. 7B ), the sprags 405 establish a power transmission connection between the inner ring 401 and the outer ring 402. When the sprags 405 are in a tilted position (see FIGS. 6B and 8B ), the power transmission connection between the inner ring 401 and the outer ring 402 is released. The actuating member 404 is disposed between the outer ring 402 and the fixed ring 403 and can be aligned or displaced relative to the fixed ring 403 so that the sprags 405 are in an upright or tilted position.

[0029] The drive device 1 further includes a control mechanism 60, which allows the relative position of the internal gear 201 and the housing 50 to change in the circumferential direction. The control mechanism 60 limits the change in the relative position of the internal gear 201 and the housing 50 in the circumferential direction between a first predetermined position and a second predetermined position. When the internal gear 201 is in the first predetermined position in the circumferential direction relative to the housing 50, the operating member 404 releases the power transmission connection between the inner ring 401 and the outer ring 402. At this time, the second clutch unit 40 is in a disengaged state and is unable to transmit torque. When the internal gear 201 is in the second predetermined position in the circumferential direction relative to the housing 50, the inner ring 401 and the outer ring 402 are in a power transmission connection. At this time, the second clutch unit 40 is in an engaged state and is able to transmit torque.

[0030] The control mechanism 60 includes a housing side member 601 formed in the housing 50 and an internal gear side member 602 formed in the internal gear 201. A groove is formed in the housing side member 601. The internal gear side member 602 is partially housed in the groove of the housing side member 601 and can move a predetermined distance in the circumferential direction relative to the housing side member 601. The internal gear side member 602 and the operating member 404 can rotate together by forming the internal gear side member 602 and the operating member 404 as a single unit.

[0031] The control mechanism 60 further includes an elastic member 603 as a limiting member. The elastic member 603 biases the internal gear side member 602 so that the internal gear 201 is in a first predetermined position relative to the housing 50, thereby limiting the internal gear 201 to the first predetermined position relative to the housing 50 without any other external force.

[0032] As shown in FIG. 6A , when the drive unit 1 is in first gear, the sun gear 202 is driven by the motor M to rotate in one circumferential direction, the elastic member 603 biases the internal gear side member 602, and the internal gear 201 is in a first predetermined position relative to the housing 50. As shown in FIG. 6B , the actuating member 404 formed integrally with the internal gear side member 602 is shifted relative to the fixed ring 403 and is in a disengaged position. The sprags 405 attached to the fixed ring 403 are pushed by the actuating member 404 and assume a tilted position. At this time, the sprags 405 do not engage with the inner ring 401 and the outer ring 402, and therefore the power transmission connection between the inner ring 401 and the outer ring 402 is released. This causes the second clutch unit 40 to enter a disengaged state.

[0033] As shown in Fig. 7A , when the drive unit 1 is in second gear, the sun gear 202 is driven by the motor M to rotate in the other circumferential direction, and the internal gear 201 is urged by the planetary gears 204 in the direction opposite to the rotational direction of the housing 50. The internal gear 201 is in a second predetermined position relative to the housing 50 as a result of the internal gear side member 602 moving rearward in the rotational direction relative to the housing side member 601 against the urging force of the elastic member 603. During the process of shifting from first gear to second gear, the internal gear side member 602 moves rearward in the rotational direction relative to the housing side member 601 by a small distance, for example, about 1 m, and the internal gear 201 moves from the first predetermined position to a second predetermined position relative to the housing 50. As shown in Fig. 7B , when the internal gear 201 moves to the second predetermined position, the operating member 404 is approximately aligned with the fixed ring 403 and is in the engagement position. Therefore, the sprags 405 attached to the fixed ring 403 are not pushed by the operating member 404. Because the rotational speed of the inner ring 401 is higher than the rotational speed of the outer ring 402, the sprags 405 switch to an upright position. Then, the sprags 405 engage with the inner ring 401 and the outer ring 402, thereby achieving a power transmission connection between the inner ring 401 and the outer ring 402. As a result, the second clutch unit 40 is in an engaged state.

[0034] As shown in FIG. 8A , when the vehicle is pushed backward by human power, the drive wheel T rotates to one side in the circumferential direction, and the elastic member 603 biases the internal gear member 602. Therefore, the internal gear 201 is in a first predetermined position relative to the housing 50. As shown in FIG. 8B , the actuating member 404 is shifted relative to the fixed ring 403 and is in a disengaged position. The sprags 405 attached to the fixed ring 403 are pushed by the actuating member 404 to a tilted position, and the sprags 405 do not engage with the inner ring 401 and the outer ring 402. Therefore, the power transmission connection between the inner ring 401 and the outer ring 402 is released. As a result, the second clutch unit 40 is in a disengaged state.

[0035] In this embodiment, instead of providing two one-way clutches and one clutch for disengaging when reversing by hand, the first clutch unit 30 is a one-way clutch and the second clutch unit 40 is a controllable one-way clutch. In other words, the drive wheels T can be rotated in second gear and in reverse with only one one-way clutch and one controllable one-way clutch, which simplifies the structure.

[0036] 9 to 11B, a driving device 1 according to another embodiment (modification) of the present invention will be described. The driving device 1 according to this modification differs from the driving device 1 according to the above embodiment in the specific structure of the coupling portion that realizes the power transmission connection between the inner ring 401 and the outer ring 402. More specifically, in this modification, the coupling portion is a ratchet pawl 406. The ratchet pawl 406 is rotatably attached to the outer ring 402, and the inner ring 401 is formed with a coupling recess that can be coupled to the ratchet pawl 406.

[0037] Fig. 9 is a cross-sectional schematic diagram showing a drive unit 1 according to another embodiment of the present invention. Fig. 10A is a cross-sectional schematic diagram showing the state of the second clutch unit 40 when the drive unit 1 is in first gear or when the drive unit 1 has stopped driving and the vehicle is being pushed backward by human power, where Fig. 10B is a cross-sectional schematic diagram showing the state of the second clutch unit 40 when the drive unit 1 is in second gear, where Fig. 11A is a cross-sectional schematic diagram showing the state of the second clutch unit 40 when the drive unit 1 is in second gear, where Fig. 1 ....

[0038] As shown in Fig. 10A, when the drive unit 1 is in first gear or when the vehicle is being pushed backward by human power, the elastic member 603 biases the internal gear side member 602. Therefore, the internal gear 201 is in a first predetermined position relative to the housing 50. As shown in Fig. 10B, the operating member 404 resists the biasing force of a spring (e.g., a torsion spring) (not shown) on the ratchet pawl 406, causing the ratchet pawl 406 to assume a tilted position without being coupled to the inner ring 401. As a result, the power transmission connection between the inner ring 401 and the outer ring 402 is released.

[0039] As shown in FIG. 11A , when the drive unit 1 is in second gear, the sun gear 202 is driven by the motor M to rotate in the other circumferential direction, and the internal gear side member 602 moves rearward in the rotational direction relative to the housing side member 601 against the biasing force of the elastic member 603. As a result, the internal gear 201 is in a second predetermined position relative to the housing 50. During the shift from first gear to second gear, the internal gear side member 602 moves rearward in the rotational direction by a small distance, for example, approximately 2 m, relative to the housing side member 601, causing the internal gear 201 to move from the first predetermined position to the second predetermined position relative to the housing 50. As shown in FIG. 11B , the operating member 404 does not bias the ratchet pawl 406. Under the action of a spring (not shown), the ratchet pawl 406 switches to an upright position and engages with the inner ring 401. As a result, a power transmission connection is achieved between the inner ring 401 and the outer ring 402. As a result, the second clutch unit 40 is brought into an engaged state.

[0040] (Vehicle with drive unit) This embodiment further provides a vehicle including the drive unit 1, and the vehicle may particularly be a vehicle having two or more wheels, with the drive unit 1 attached to at least one drive wheel T.

[0041] (Operations and Effects) The configuration and operations and effects of the present embodiment will be described below.

[0042] (1) A drive device 1 that transmits torque from a drive source (motor M) to a driven object includes a planetary gear mechanism 20, a first clutch unit 30, a second clutch unit 40, and a housing 50. The housing 50 is fixedly connected to the driven object. The planetary gear mechanism 20 includes an internal gear 201, a sun gear 202, a planet carrier 203, and a planet gear 204. The drive device 1 has a first torque transmission path and a second torque transmission path. Torque can be transmitted from the drive source (motor M) to the driven object alternatively via the first torque transmission path or the second torque transmission path. The sun gear 202 is driven by the drive source (motor M). When the sun gear 202 is driven by a drive source (motor M) to rotate in one circumferential direction, the first clutch unit 30 is engaged and the second clutch unit 40 is disengaged, thereby transmitting torque to the driven object via the first torque transmission path, causing the driven object to rotate in the other circumferential direction; when the sun gear 202 is driven by a drive source (motor M) to rotate in the other circumferential direction, the first clutch unit 30 is disengaged and the second clutch unit 40 is engaged, thereby transmitting torque to the driven object via the second torque transmission path, causing the driven object to rotate in the other circumferential direction; when the driven object rotates in one circumferential direction, the second clutch unit 40 is disengaged, thereby providing a drive device 1.

[0043] According to this configuration, two-speed shifting can be achieved even in the drive unit 1 including a single planetary gear mechanism 20. Furthermore, when the vehicle is pushed or pulled backward by human power or the like, locking of the drive wheels T can be avoided and the drive wheels T can be rotated backward, allowing the vehicle to be moved backward smoothly.

[0044] (2) The second clutch unit 40 is located between the planetary carrier 203 and the housing 50 in the second torque transmission path.

[0045] This configuration allows the torque capacity of the second clutch unit 40 to be reduced, which is advantageous in terms of layout.

[0046] (3) The second clutch unit 40 includes an inner ring 401, an outer ring 402 arranged radially outside the inner ring 401, a connecting portion (sprags 405, ratchet pawls 406) arranged between the inner ring 401 and the outer ring 402, and an operating member 404 that controls the state of the connecting portion and realizes or releases a transmission connection between the inner ring 401 and the outer ring 402 via the connecting portion.

[0047] According to this configuration, the second clutch unit 40 can be controlled to be engaged or disengaged, and the drive structure can be simplified.

[0048] (4) The drive unit 1 further includes a control mechanism 60 that limits the relative circumferential position between the internal gear 201 and the housing 50 between a first predetermined position and a second predetermined position. When the internal gear 201 is in the first predetermined circumferential position relative to the housing 50, the operating member 404 releases the transmission connection between the inner ring 401 and the outer ring 402, and the second clutch unit 40 is in a separated state and is unable to transmit torque. When the internal gear 201 is in the second predetermined circumferential position relative to the housing 50, the inner ring 401 and the outer ring 402 are in a transmission connection, and the second clutch unit 40 is in a coupled state and is able to transmit torque.

[0049] With this configuration, the state of the second clutch unit 40 can be controlled by rotating the internal gear 201 relative to the housing 50, and the second clutch unit 40 can be controlled to be connected or disconnected without adding any other parts.

[0050] (5) The control mechanism 60 includes a housing side member 601 formed on the housing 50 and an internal gear side member 602 formed on the internal gear 201, and controls the state of the joint by the internal gear side member 602 and the operating member 404 rotating integrally.

[0051] According to this configuration, the second clutch unit 40 can be controlled to be engaged or disengaged with a simple structure.

[0052] (6) The control mechanism 60 includes a restricting member (elastic member 603 ) that can restrict the internal gear 201 to the first predetermined position relative to the housing 50 .

[0053] According to this configuration, the second clutch unit 40 can be reliably connected or disconnected in a controlled manner.

[0054] (7) The restricting member is the elastic member 603 that biases the internal gear side member 602 so that the internal gear 201 is in the first predetermined position relative to the housing 50 .

[0055] According to this configuration, the second clutch unit 40 can be reliably put into the disengaged state with a simple structure.

[0056] (8) The first clutch unit 30 is a one-way clutch.

[0057] According to this configuration, two-speed shifting can be achieved with a simple structure.

[0058] (9) The connecting portion is the sprag 405. When the sprag 405 is in an upright position, the sprag 405 is connected to the inner ring 401 and the outer ring 402, thereby realizing a power transmission connection between the inner ring 401 and the outer ring 402. When the sprag 405 is in a tilted position, the power transmission connection between the inner ring 401 and the outer ring 402 is released.

[0059] (10) The connecting portion is a ratchet pawl 406, which is attached to one of the inner ring 401 and the outer ring 402. When the ratchet pawl 406 is in an upright position, the ratchet pawl 406 is connected to the other of the inner ring 401 and the outer ring 402, thereby realizing a power transmission connection between the inner ring 401 and the outer ring 402. When the ratchet pawl 406 is in a tilted position, the power transmission connection between the inner ring 401 and the outer ring 402 is released.

[0060] According to these configurations, the second clutch unit 40 can be reliably put into a disengaged state with a simple structure, and the impact when the second clutch unit 40 is engaged can be reduced.

[0061] (11) The vehicle has a drive unit 1.

[0062] This configuration prevents the drive wheels T from locking when the vehicle is pushed or pulled backward by human power.

[0063] In the drive unit 1 according to this embodiment, when the sun gear 202 is driven by the drive source (motor M) to rotate in one circumferential direction, the first clutch unit 30 is engaged and the second clutch unit 40 is disengaged, thereby transmitting torque to the driven object via the first torque transmission path and causing the driven object to rotate in the other circumferential direction; when the sun gear 202 is driven by the drive source (motor M) to rotate in the other circumferential direction, the first clutch unit 30 is disengaged and the second clutch unit 40 is engaged, thereby transmitting torque to the driven object via the second torque transmission path and causing the driven object to rotate in the other circumferential direction; and when the driven object rotates in one circumferential direction, the second clutch unit 40 is disengaged. This prevents the drive wheels T from locking when a vehicle including the drive unit 1 is pushed or pulled backward by human power.

[0064] Although an embodiment of the present invention has been described above, the above embodiment merely shows one application example of the present invention, and is not intended to limit the technical scope of the present invention to the specific configuration of the above embodiment.

[0065] For example, in the above embodiment, the inner ring of the first clutch unit 30 is fixed to the stator shaft O of the motor M to lock the planetary carrier 203 and the stator shaft O, but it goes without saying that the inner ring of the first clutch unit 30 may also be fixed to another member that does not move relative to the mounting object of the drive unit 1.

[0066] Furthermore, in the above embodiment, the planetary carrier 203 functions as the outer ring of the first clutch unit 30 and as the inner ring of the second clutch unit 40, but it goes without saying that at least one of the first clutch unit 30 and the second clutch unit 40 may have an inner ring and an outer ring independently.

[0067] In the above embodiment, the motor M is an outer rotor type motor, but is not limited to this and may be an inner rotor type motor.

[0068] In the above embodiment, the first torque transmission path and the second torque transmission path are both realized by the planetary gear mechanism 20, but the present invention is not limited to this, and the torque transmission paths may be realized by different transmission mechanisms by changing the structure of the transmission mechanism. In addition, while the reduction ratio is 2.95 in first gear, it goes without saying that the reduction ratio can be adjusted by setting a different gear ratio.

[0069] Furthermore, in the above embodiment, the ratchet pawl 406 is rotatably attached to the outer ring 402, and the inner ring 401 is formed with a coupling recess that can be coupled to the ratchet pawl 406, but the present invention is not limited to this, and the ratchet pawl 406 may be rotatably attached to the inner ring 401, and the outer ring 402 may be formed with a coupling recess that can be coupled to the ratchet pawl 406.

[0070] Furthermore, in the above embodiment, the first clutch unit 30 is a one-way clutch and the second clutch unit 40 is a controllable one-way clutch, but the present invention is not limited to this, and both the first clutch unit 30 and the second clutch unit 40 may be controllable one-way clutches.

[0071] In the above embodiment, the drive unit 1 is a two-speed drive unit. However, it goes without saying that the drive unit 1 may have at least two speed stages.

[0072] REFERENCE SIGNS LIST 1 Drive device M Motor R Rotor S Stator T Drive wheel O Stator shaft 10 Rotor holder 20 Planetary gear mechanism 201 Internal gear 202 Sun gear 203 Planet carrier 204 Planetary gear 30 First clutch unit 40 Second clutch unit 401 Inner ring 402 Outer ring 403 Fixed ring 404 Operating member 405 Sprag 406 Ratchet pawl 50 Housing 60 Control mechanism 601 Housing side member 602 Internal gear side member 603 Elastic member

Claims

1. A drive device (1) that transmits torque from a drive source (M) to a driven object (T), comprising a planetary gear mechanism (20), a first clutch unit (30), a second clutch unit (40), and a housing (50), wherein the housing (50) is fixedly connected to the driven object (T), the planetary gear mechanism (20) includes an internal gear (201), a sun gear (202), a planet carrier (203), and planet gears (204), the drive device (1) has a first torque transmission path and a second torque transmission path, and is capable of transmitting torque from the drive source (M) to the driven object (T) alternatively via the first torque transmission path or the second torque transmission path, When the sun gear (202) is driven by the driving source (M) to rotate in one circumferential direction, the first clutch unit (30) is engaged and the second clutch unit (40) is disengaged, thereby transmitting torque to the driven object (T) via the first torque transmission path, and the driven object (T) rotates in the other circumferential direction; when the sun gear (202) is driven by the driving source (M) to rotate in the other circumferential direction, the first clutch unit (30) is disengaged and the second clutch unit (40) is engaged, thereby transmitting torque to the driven object (T) via the second torque transmission path, and the driven object (T) rotates in the other circumferential direction; when the driven object (T) rotates in one circumferential direction, the second clutch unit (40) is disengaged.

2. A drive device (1) according to claim 1, wherein the second clutch unit (40) is located between the planet carrier (203) and the housing (50) in the second torque transmission path.

3. A drive device (1) according to claim 2, wherein the second clutch unit (40) includes an inner ring (401), an outer ring (402) arranged radially outward of the inner ring (401), coupling portions (405, 406) arranged between the inner ring (401) and the outer ring (402), and an operating member (404) that controls the state of the coupling portions (405, 406) and establishes or releases a power transmission connection between the inner ring (401) and the outer ring (402) via the coupling portions (405, 406).

4. A drive device (1) as set forth in claim 3, further comprising a control mechanism (60) that limits the relative position of the internal gear (201) and the housing (50) in the circumferential direction between a first predetermined position and a second predetermined position, wherein when the internal gear (201) is at the first predetermined position in the circumferential direction relative to the housing (50), the operating member (404) releases the power transmission connection between the inner ring (401) and the outer ring (402), and the second clutch unit (40) is in a separated state and is unable to transmit torque, and when the internal gear (201) is at the second predetermined position in the circumferential direction relative to the housing (50), the inner ring (401) and the outer ring (402) are in a connected state and the second clutch unit (40) is able to transmit torque.

5. A drive device (1) according to claim 4, wherein the control mechanism (60) includes a housing side member (601) formed on the housing (50) and an internal gear side member (602) formed on the internal gear (201), and the internal gear side member (602) and the operating member (404) rotate together to control the state of the coupling portions (405, 406).

6. A drive device (1) according to claim 4 or 5, wherein the control mechanism (60) includes a limiting member (603) capable of limiting the internal gear (201) to the first predetermined position relative to the housing (50).

7. A drive device (1) according to claim 6, wherein the limiting member (603) is an elastic member (603) that biases the internal gear side member (602) so that the internal gear (201) is in the first predetermined position relative to the housing (50).

8. A drive device (1) according to any one of claims 3 to 5, wherein the first clutch unit (30) is a one-way clutch.

9. A drive device (1) according to any one of claims 3 to 5, wherein the coupling parts are sprags (405), and when the sprags (405) are in an upright position, the sprags (405) couple to the inner ring (401) and the outer ring (402), thereby realizing a power transmission connection between the inner ring (401) and the outer ring (402), and when the sprags (405) are in a tilted position, the power transmission connection between the inner ring (401) and the outer ring (402) is released.

10. A drive device (1) according to any one of claims 3 to 5, wherein the coupling portion is a ratchet pawl (406) attached to one of the outer ring (402) and the inner ring (401), and when the ratchet pawl is in an upright position, the ratchet pawl (406) couples with the other of the inner ring (401) and the outer ring (402), thereby realizing a power transmission connection between the inner ring (401) and the outer ring (402), and when the ratchet pawl (406) is in a tilted position, the power transmission connection between the inner ring (401) and the outer ring (402) is released.

11. A vehicle comprising a drive device (1) according to any one of claims 1 to 10.

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