JP2006188211A - Wheel support/drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanism for simplifying a structure for realizing function for supporting a wheel and function for driving the wheel. <P>SOLUTION: The wheel support/drive device is provided on a vehicle, vertically movably supports the wheel relative to a vehicle body and drives the wheel. The device includes a motor supported on the vehicle body and a first rotation body rotated by the motor; a second rotation body rotated coaxially and integrally with the wheel; a first connection mechanism for connecting rotation central axis of the first rotation body and the wheel in the state that the wheel can be reciprocatingly swinged around the rotation center making the rotation center of the first rotation body as the rotation center; and a second connection mechanism for elastically connecting the wheel and the vehicle body. The first rotation body is rotated by the motor in a direction crossing a vertical direction around a rotation center deviated from the rotation center of the wheel. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for supporting a wheel in a vehicle so as to be movable up and down with respect to the vehicle body and driving the wheel by a motor, and in particular, a function for supporting the wheel and a function for driving the wheel. The present invention relates to a technique for simplifying the structure.

  There is already known a vehicle in which a wheel is supported so as to be movable up and down with respect to a vehicle body, and the wheel is driven by a motor (for example, see Patent Document 1).

In this type of vehicle, with respect to the same wheel, it is required that a function of supporting the wheel so as to be movable up and down and a function of driving the wheel by a motor are realized. The former function is called a suspension function for suspending wheels on the vehicle body.
JP-A-6-48192

  Conventionally, in this type of vehicle, the motor is mounted on the vehicle only to drive the wheels, and the same motor is not designed to contribute to the suspension function. Therefore, in this conventional vehicle, it has been difficult to simplify the structure necessary for realizing the wheel driving function and the suspension function.

  Further, in this conventional vehicle, the motor is fixed to the wheel of the wheel, and the motor is also moved up and down as the wheel moves up and down. Therefore, in this conventional vehicle, the weight of the motor is added to the unsprung load of the vehicle, and as a result, it is difficult to reduce the unsprung load.

  Against the background described above, the present invention provides a function for supporting a wheel and a function for driving the wheel in a technology for supporting the wheel in a vehicle so as to move up and down relative to the vehicle body and driving the wheel by a motor. The problem is to simplify the structure for realizing the above.

  The following aspects are obtained by the present invention. Each aspect is divided into sections, each section is given a number, and is described in a form that cites other section numbers as necessary. This is to facilitate understanding of some of the technical features that the present invention can employ and combinations thereof, and the technical features that can be employed by the present invention and combinations thereof are limited to the following embodiments. Should not be interpreted. That is, it should be construed that it is not impeded to appropriately extract and employ the technical features described in the present specification as technical features of the present invention although they are not described in the following embodiments.

  Further, describing each section in the form of quoting the numbers of the other sections does not necessarily prevent the technical features described in each section from being separated from the technical features described in the other sections. It should not be construed as meaning, but it should be construed that the technical features described in each section can be appropriately made independent depending on the nature.

(1) A wheel support / drive device that is provided in a vehicle and supports the wheel so as to be movable up and down relative to the vehicle body, and drives the wheel,
A motor supported by the vehicle body and a first rotating body rotated by the motor;
A second rotating body that is coaxially and integrally rotated with the wheel;
A first coupling mechanism that couples the first rotating body and the rotation center axis of the wheel to each other in a state where the wheel can reciprocally swing around the center of rotation of the first rotating body. When,
A wheel support / drive device comprising: a second connection mechanism that elastically connects the wheel and the vehicle body to each other;
The wheel support / drive device according to claim 1, wherein the first rotating body is rotated by the motor about a rotation center eccentric from a rotation center of the wheel in a direction intersecting a vertical direction.

  In this wheel support / drive device, the wheel can reciprocate around the rotation center of the first rotating body, and the rotation center shaft 34 of the wheel is connected to the first rotating body by the first connecting mechanism. In such a configuration, the first rotating body is rotated by the motor around the rotation center that is eccentric from the rotation center of the wheel in the direction intersecting the vertical direction.

  Therefore, in this wheel support / drive device, the rotation of the wheel (spinning) and the reciprocating swing (revolution) around the rotation center of the first rotating body of the same wheel are realized by the same motor. While the rotation of the wheel contributes to the running (driving) of the vehicle, the reciprocating rocking of the wheel contributes to the suspension function of the vehicle. The characteristic of the reciprocating oscillation can be controlled by the motor. Furthermore, in this wheel support / drive device, the wheels are elastically connected to the vehicle body by the second connection mechanism.

  Therefore, according to this wheel support / drive device, the reciprocal swing of the wheel, the characteristic of which can be controlled by the motor, and the joint action of the wheel being elastically connected to the vehicle body, It is possible to realize a suspension function that suspends the vehicle body on the wheels so as to be movable at least up and down.

  That is, according to this wheel support / drive device, it is possible to realize the function of driving the vehicle and the suspension function together by the same motor, and therefore these functions must be realized by separate actuators. Compared to the case where it is necessary, it becomes easy to simplify the structure necessary to realize these functions.

  Further, in this wheel support / drive device, the motor that realizes the rotation and reciprocation of the wheel is not fixed to the wheel but supported by the vehicle body.

  Therefore, according to this wheel support / drive device, the motor does not need to move up and down with the vertical movement of the wheel, so that the unsprung load of the vehicle is reduced as compared with the case where the motor is fixed to the wheel. It becomes easy.

  In this wheel support / drive device, the trajectory drawn by the wheel in the side view of the wheel, that is, the motion trajectory of the wheel coincides with the swing center of the second rotating body as the second rotating body swings back and forth. It depends on whether the position of the rotation center of the first rotating body is constant or variable in a side view of the vehicle.

  Specifically, for example, when the position of the swing center is invariant in a side view of the vehicle, the movement locus of the wheels forms an arc shape. On the other hand, when the position of the swing center is variable in the vehicle front-rear direction in a side view of the wheel, the wheel movement trajectory is such that the rotation center of the wheel can move. Depends on the direction regulated by For example, if the direction in which the rotation center of the wheel can move is restricted so as to coincide with the vertical direction of the vehicle, the movement locus of the wheel is formed in the vertical direction of the vehicle. In this case, although the wheel is reciprocally swung around the rotation center of the first rotating body, the wheel is substantially reciprocated linearly in the vertical direction of the vehicle.

  The unsprung load of the vehicle (especially the load corresponding to the inertia in the vertical direction of the vehicle) is applied to the first rotating body so that the position of the rotation center of the first rotating body is variable in the longitudinal direction of the vehicle in a side view of the wheel. Even when the first rotating body is mounted on the vehicle body, the number of rotations of the first rotating body does not increase as compared with the case where the first rotating body is mounted on the vehicle body so that the position of the rotation center of the first rotating body is unchanged in a side view of the wheel.

  Therefore, when implementing the wheel support / drive device according to this section, it is possible to satisfy the requirement of optimizing the motion trajectory of the wheel separately from the problem that the unsprung load of the vehicle increases. .

  This wheel support / drive device can be implemented, for example, in such a manner that the motor and the first rotating body are coaxially connected to each other, or in a manner that they are non-coaxially connected to each other.

  In the wheel support / drive device, for example, the connection between the first rotator and the second rotator is performed in the first mode in which the gear mechanism is used, or the first rotator and the second rotator. It is possible to implement in a second mode that is performed using an endless circulation body (for example, a belt, a chain, or the like) wound around.

  Both the first and second modes are classified into contact types that transmit force between the first rotating body and the second rotating body through the contact surface. However, in this wheel support / drive device, the connection between the first rotating body and the second rotating body is, for example, a fluid sealed in a closed space in accordance with the same principle as that in which a force is transmitted in a fluid type torque converter. It is also possible to implement in a non-contact manner, such as a mode in which is used as a pressure transmission medium between the first rotating body and the second rotating body.

  The “motor” in this section is used so as to be supported by the vehicle body in a state in which it cannot move at least in the vertical direction with respect to the vehicle body.

(2) The first rotating body is a drive gear,
The second rotating body is a driven gear that meshes with the drive gear and is rotated.
The first coupling mechanism includes a suspension arm that couples the driven gear and the driven gear to each other in an engaged state in a state where the driven gear has a constant radius around the drive gear and can swing back and forth.
The wheel support / drive device according to item (1), wherein the second connection mechanism includes a suspension spring that elastically connects the wheel and the vehicle body to each other.

  In this wheel support / drive device, the first rotating body and the second rotating body are connected to each other using a gear mechanism. Specifically, the driving gear and the driven gear that mesh with each other are rotated. They are linked together using a combination. The drive gear and the driven gear are connected to each other by a suspension arm (or suspension link) in a state where the driven gear can reciprocally swing around the drive gear with a certain radius. Furthermore, the wheel and the vehicle body are elastically connected to each other by a suspension spring.

  Therefore, according to this wheel support / drive device, by the cooperation with the suspension arm, the motor that realizes not only the driving (spinning) of the wheel but also the reciprocating swing (revolution) of the wheel, and the suspension spring, The suspension function of the vehicle with respect to the wheels is realized.

(3) a sun gear that is coaxial with and rotated integrally with the wheel;
A ring gear that is coaxial with and rotated relative to the wheel;
A plurality of pinion gears arranged side by side along one circumference coaxial with the sun gear, the sun gear meshing with its outer tooth surface, and the ring gear meshing with its inner tooth surface;
A carrier that holds the plurality of pinion gears so that the relative positional relationship between the rotation centers of the plurality of pinion gears is maintained, and a planetary gear mechanism is configured by the sun gear, the ring gear, the plurality of pinion gears, and the carrier,
The first rotating body is configured as one of the plurality of pinion gears,
The wheel support / drive device according to (1) or (2), wherein the second rotating body is configured as the sun gear.

  In the wheel support / drive device, the first rotating body and the second rotating body are connected to each other using a planetary gear mechanism that is an example of a gear mechanism. In the planetary gear mechanism, a plurality of pinion gears that simultaneously mesh with the sun gear are concentrically connected to each other by a carrier. In this planetary gear mechanism, the pinion gear is also called a planetary gear, and the ring gear is also called an outer gear or an internal gear.

  Even if a large force tries to act between any one of the plurality of pinion gears and the sun gear, the internal forces acting on the plurality of pinion gears act so as to cancel each other. That is, the generation of a biased force on any of the pinion gears is automatically suppressed.

  In the wheel support / drive device according to this aspect, the first rotating body is configured as one of the plurality of pinion gears connected to each other by the carrier. Therefore, the one pinion gear and the second rotating body are connected to each other. When a corresponding sun gear meshes with each other and rotates, even if a large force is about to act between them, the occurrence of a force biased to that one pinion gear is suppressed.

  Therefore, according to this wheel support / drive device, a force is applied between the first rotating body and the second rotating body even though the first rotating body is eccentric with respect to the second rotating body. It becomes easy to mechanically stabilize the transmission mechanism.

(4) a sun gear that is coaxial with the wheel and rotated relative thereto;
A ring gear that is coaxially and integrally rotated with the wheel;
A plurality of pinion gears arranged side by side along a circumference of the same axis as the sun gear, the sun gear meshing with its outer tooth surface, and the ring gear meshing with its inner tooth surface;
A carrier that holds the plurality of pinion gears so that the relative positional relationship between the rotation centers of the plurality of pinion gears is maintained, and a planetary gear mechanism is configured by the sun gear, the ring gear, the plurality of pinion gears, and the carrier,
The first rotating body is configured as one of the plurality of pinion gears,
The wheel support / drive device according to (1) or (2), wherein the second rotating body is configured as the ring gear.

  In the wheel support / drive device, the first rotating body and the second rotating body are connected to each other using a planetary gear mechanism that is an example of a gear mechanism. In the planetary gear mechanism, a plurality of pinion gears that simultaneously mesh with the ring gear are concentrically connected to each other by a carrier. In this planetary gear mechanism, the pinion gear is also called a planetary gear, and the ring gear is also called an outer gear or an internal gear.

  Even if a large force acts between any one of the plurality of pinion gears and the ring gear, the internal forces acting on the plurality of pinion gears act so as to cancel each other. That is, the generation of a biased force on any of the pinion gears is automatically suppressed.

  In the wheel support / drive device according to this aspect, the first rotating body is configured as one of the plurality of pinion gears connected to each other by the carrier. Therefore, the one pinion gear and the second rotating body are connected to each other. When a corresponding ring gear rotates while meshing with each other, even if a large force is about to act between them, the generation of a force biased to the one pinion gear is suppressed.

  Therefore, according to this wheel support / drive device, a force is applied between the first rotating body and the second rotating body even though the first rotating body is eccentric with respect to the second rotating body. It becomes easy to mechanically stabilize the transmission mechanism.

(5) The wheel support / drive device according to any one of (1) to (4), wherein the motor is coaxially coupled to the first rotating body.

  According to this wheel support / drive device, it is easier to simplify the structure for connecting the motor and the first rotating body to each other than when the motor is connected non-coaxially to the first rotating body.

(6) The wheel is a non-steered wheel that is not steered during steering of the vehicle,
The wheel support / drive device according to any one of (1) to (5), wherein the motor and the first rotating body are supported by the vehicle body at fixed positions.

(7) The wheel is a steered wheel that is steered during steering of the vehicle.
The motor and the first rotating body are supported by the vehicle body so as to be rotated integrally with the steered wheels during steering of the vehicle. Wheel support / drive device.

  In this wheel support / drive device, rotation and reciprocation of the steered wheels are realized by a motor. Furthermore, during the steering of the vehicle, the motor and the first rotating body are rotated integrally with the steered wheels. Therefore, the angle formed by the rotation axis of the motor and the rotation axis of the first rotating body does not change during steering.

  On the other hand, in the case of transmitting rotation between two axes that intersect at an angle via a universal joint, in general, in order to ensure the transmission efficiency, the change range of the angle between the two axes is a certain range. Limited to

  For this reason, the wheel support / drive device according to any one of (1) to (4) is configured such that the angle formed between the rotation axis of the motor and the rotation axis of the first rotating body changes during steering of the vehicle. In order to efficiently transmit the rotation between the motor and the first rotating body regardless of the angle change, the motor and the first rotating body are connected to each other via a universal joint. In the case of implementation in the aspect, the maximum value of the angle during steering is limited, and as a result, the maximum value of the turning angle of the wheel is also limited.

  On the other hand, in the wheel support / drive device according to this aspect, the angle formed between the rotation axis of the motor and the rotation axis of the first rotating body does not change during steering. It is possible to avoid a situation in which the maximum value of the turning angle of the wheel is limited in order to avoid a decrease in the transmission efficiency of rotation between the two.

  The “motor and first rotating body” in this section are supported by the vehicle body so as to be rotated in a plane generally parallel to the horizontal plane of the vehicle integrally with the steered wheels during steering of the vehicle, for example.

(8) The wheel support / drive device according to any one of (1) to (7), further including a control device that controls an output torque of the motor by controlling a drive signal to the motor.

  In this wheel support / drive device, if the output torque of the motor is controlled, the swing characteristics of the wheel are controlled. By controlling the swing characteristics, for example, it is possible to control the bounce characteristics and / or rebound characteristics of the wheels while the vehicle is running. By controlling these bounce characteristics and / or rebound characteristics, for example, it is possible to improve the riding comfort of the vehicle affected by the vibration of the wheels and the performance of the wheels following the unevenness of the road surface.

  For example, when traveling so that the wheel passes through a discontinuous part such as a protrusion or a step on the road surface, a large force is suddenly input from the road surface to the vehicle body or even after passing through the discontinuous part. The phenomenon that the vibration of the continuation continues is likely to occur. It is possible to implement the wheel support / drive device according to this section in a manner in which the output torque of the motor is controlled for the purpose of suppressing this phenomenon.

(9) The control device includes a damping characteristic control unit that controls a damping characteristic in the vertical movement of the wheel with respect to the vehicle body by controlling a swing characteristic of the wheel about the swing center through the motor. The wheel support / drive device according to item (8).

  According to this wheel support / drive device, in order to attenuate the vibration generated in the wheel, it is not indispensable to mount the shock absorber for damping the vibration exclusively on the vehicle. Furthermore, in order to control the damping characteristic in the vertical movement of the wheel with respect to the vehicle body, it is not indispensable to mount an actuator other than the motor for reciprocating the wheel on the vehicle.

(10) The wheel support / drive device according to (8) or (9), wherein the control device includes a wheel drive torque control unit that controls a drive torque around the rotation center of the wheel via the motor. .

  An example of the “wheel drive torque control unit” in this section is to suppress the vibration of the wheel caused by the wheel traveling so as to pass the discontinuous part on the road surface, thereby improving the ride comfort of the vehicle. This is done to improve the road surface following ability of the wheels.

  Hereinafter, some of the more specific embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a side view showing a mechanical configuration of a wheel support / drive device 10 according to the first embodiment of the present invention. However, the wheel 14 is a virtual part. The wheel support / drive device 10 is mounted on a vehicle including a vehicle body 12 and a plurality of wheels 14 including left and right front wheels and left and right rear wheels. In FIG. 1, the wheel support / drive device 10 is shown focusing on one of the wheels 14.

  As shown in FIG. 1, the wheel support / drive device 10 includes, for each wheel 14, a motor 20 fixed to the vehicle body 12 and a drive gear 24 that is coaxially connected to a rotation shaft 22 of the motor 20. I have. The rotational center of the drive gear 24 is eccentric from the rotational center of the wheel 14 in a direction intersecting the vertical direction. In the present embodiment, the motor 20 is supported by the vehicle body 12 so that relative displacement with respect to the vehicle body 12 does not substantially occur in all directions. The drive gear 24 can rotate (spin) in both directions indicated by an arrow A in FIG.

  On the other hand, the wheel 14 is coaxially provided with a driven gear 30 that is meshed and driven by a drive gear 24. The wheel 14 is rotated integrally with the driven gear 30. The driven gear 30 can rotate (spin) in both directions indicated by an arrow B in FIG.

  The wheel support / drive device 10 further includes a suspension arm 40 that connects the rotation shaft 32 of the drive gear 24 and the rotation shaft 34 of the driven gear 30 to each wheel 14. Specifically, the suspension arm 40 connects the drive gear 24 and the driven gear 30 in a meshed state with the driven gear 30 having a certain radius around the drive gear 24 and capable of swinging back and forth. is doing. Therefore, the rotation center of the wheel 14 and the rotation center of the driven gear 30 that coincide with each other can swing (revolve) in both directions indicated by an arrow C in FIG.

  As shown in FIG. 1, the wheel support / drive device 10 further includes a suspension spring 50 for each wheel 14. The suspension spring 50 elastically connects the vehicle body 12 and the wheel 14 to each other. The suspension spring 50 is expanded and contracted in both directions indicated by an arrow D in FIG. 1 as the wheel 14 is reciprocally swung (movement including vertical movement). The suspension spring 50 realizes elastic reciprocating rocking of the wheel 14 with the rotation center of the drive gear 24 as the rocking center.

  Therefore, in the present embodiment, the suspension arm 40 and the suspension spring 50 jointly constitute the suspension 52 of the wheel 14.

  FIG. 2 conceptually shows the electrical configuration of the wheel support / drive device 10 in a block diagram. The wheel support / drive device 10 includes a controller 60. The controller 60 is mainly configured by a computer 62, and the computer 62 is configured by connecting a CPU 64, a ROM 66, and a RAM 68 to each other via a bus (not shown) as is well known.

  As shown in FIG. 2, a motor 20 is further connected to the controller 60 for each wheel 14. In FIG. 2, “FL” means for the left front wheel, “FR” means for the right front wheel, “RL” means for the left rear wheel, and “RR”. Means for the right rear wheel.

  The controller 60 is connected to an operation state quantity sensor 80 that detects an operation state quantity input from a vehicle driver via an operation member (for example, an accelerator operation member, a brake operation member, a steering operation member, etc.). . The controller 60 is further connected to a vehicle state quantity sensor 82 that detects a movement state quantity of the vehicle (for example, vehicle speed, vehicle longitudinal acceleration, vehicle lateral acceleration, etc.).

  The controller 60 is further connected to an arm angle sensor 84 for detecting the angle of the suspension arm 40 for each wheel 14 as an example of a sensor for detecting the state quantity of the vertical movement of the wheel 14 with respect to the vehicle body 12. Yes. Further, a motor speed sensor 86 for detecting the rotational speed of the motor 20 is connected to the controller 60 as an example of a sensor for detecting the rotational state quantity of the motor 20 for each wheel 14.

  If the wheel 14 moves up and down with respect to the vehicle body 12, not only the angle of the suspension arm 40 changes, but also the rotational speed of the drive gear 24 changes due to the swing of the driven gear 30. The speed also changes. By paying attention to such a fact, in this embodiment, the arm angle sensor 84 and the motor speed sensor 86 are used to detect the state quantity of the vertical movement of the wheel 14 relative to the vehicle body 12. However, in order to achieve the same purpose, only one of the arm angle sensor 84 and the motor speed sensor 86 is used, or other sensors (for example, a sensor for detecting the stroke of the suspension spring 50) are used. It is possible to use.

  As shown in FIG. 2, the ROM 66 stores various programs in advance, including a main control program and a step-overstep control program. Both programs are executed by the CPU 64 while using the RAM 68.

  Since the main control program is not indispensable for understanding the present invention, the main control program will be briefly described without illustration. The main control program determines the vehicle plane so that the driver's intention is reflected based on the operation state quantity detected by the operation state quantity sensor 80 and the vehicle state quantity detected by the vehicle state quantity sensor 82. Movement is performed for each wheel 14 to control the motor 20 independently of each other.

  On the other hand, the step climbing control program is used when the wheel 14 travels so as to pass a discontinuous portion (hereinafter referred to as “step 90 (see FIG. 4)” for convenience of explanation) such as a step on the road surface and a protrusion. The reciprocating rocking characteristic, that is, the bounce characteristic and the rebound characteristic of each wheel 14, and the motor 20 for each wheel 14 are mutually connected so that a large vibration or a continuous vibration is not generated in the wheel 14 due to the input from the road surface to the wheel 14. Performed to control independently. The driving torque of each wheel 14 is actively controlled by the execution of the step climbing control program.

  FIG. 3 conceptually shows a flowchart of the step climbing control program. This step overpass control program is repeatedly executed for each wheel 14 while the vehicle is running. At the time of each execution, first, in step S1 (hereinafter, simply expressed as “S1”, the same applies to other steps), the arm angle sensor 84 and the motor speed sensor 86 corresponding to the current wheel 14 A detection signal representing the detection result is input.

  Next, in S2, based on the input detection signal, it is determined whether or not the current wheel 14 is in a state of starting to ride on the step 90 on the road surface. For example, it is detected that the suspension arm 40 has rotated a certain angle or more around the rotation center of the drive gear 24 from the neutral position shown in FIG. 1 in a direction approaching the vehicle body 12 (counterclockwise in FIG. 1). In this case, it is determined that the current wheel 14 is in a state of starting to ride on the step 90.

  If the current wheel 14 is not in a state of starting to ride on the step 90, the determination in S2 is NO, and it is determined in S3 that the current wheel 14 is in a normal traveling state.

  Thereafter, in S4, the normal control mode is selected, and as shown in FIG. 4A, the driving torque of the wheel 14 (torque acting on the wheel 14 in the direction in which the wheel 14 is normally rotated) is kept constant. The drive signal of the motor 20 is controlled so as to be leaned. As a result, for the wheel 14 this time, the tire pressing force by which the motor 20 presses the tire of the wheel 14 against the road surface is also kept constant.

  As shown in FIG. 4A, the drive torque of the motor 20 that rotates the wheel 14 in the forward direction acts on the sun gear 30 at a position where it is engaged with the sun gear 30 that is radially away from the rotation center of the input pinion 24. It is converted into a swinging torque around the rotation center of the input pinion 24 of the suspension arm 40 in a direction that separates the wheel 14 from the vehicle body 12 through the tangential force. Due to the converted swing torque, a tire pressing force that causes the motor 20 to press the tire of the wheel 14 against the road surface is generated.

  Prior to the execution of S4, as a result of the execution of S5, S8, S11 or S12 described later, the drive torque of the current wheel 14 may deviate from the value for normal travel. In this case, the drive torque is restored to a value for normal running by executing S4.

  This completes one execution of the step-overstep control program.

  As described above, the case where the wheel 14 is not in a state of starting to ride on the step 90 has been described. However, if the wheel 14 is in a state of starting to ride on the step 90, the determination of S2 in FIG. In S5, the step riding start control mode is selected, and the drive signal of the motor 20 is controlled so that the current drive torque of the wheel 14 is instantaneously reduced.

  For example, as shown in FIG. 4B, the current driving torque of the wheel 14 is controlled so that the current wheel 14 is instantaneously in a non-driven state. In this case, the tire pressing force by the motor 20 becomes instantaneously weaker than during normal running. Therefore, the wheel 14 this time becomes easier to approach the vehicle body 12 than during normal traveling. As a result, it is possible to prevent the vehicle body 12 from causing a large vertical movement relative to the height of the step 90 on which the current wheel 14 rides.

  Specifically, as shown in FIG. 4B, when the drive torque of the motor 20 that rotates the wheel 14 in the forward direction decreases momentarily, the suspension arm 40 swings in the direction that moves the wheel 14 away from the vehicle body 12. Dynamic torque also decreases instantaneously. Due to the instantaneous decrease, the tire pressing force by which the motor 20 presses the tire of the wheel 14 against the road surface is also instantaneously decreased. As a result, the wheel 14 becomes easier to approach the vehicle body 12 than during normal traveling, and a step (projection) 90 is obtained. It becomes easy to follow the climbing slope.

  Thereafter, in S6 in FIG. 3, detection signals are input from the arm angle sensor 84 and the motor speed sensor 86. Subsequently, in S7, the current wheel 14 is moved from the step 90 on the road surface based on the input detection signals. It is determined whether or not it is in a state of starting to descend. For example, when it is detected that the suspension arm 40 has rotated a certain angle or more around the rotation center of the drive gear 24 in a direction away from the vehicle body 12 (clockwise in the figure), the wheel 14 this time is It is determined that the vehicle starts to descend from the step 90.

  If the current wheel 14 is not in a state of starting to descend from the step 90, the determination of S7 is NO and returns to S6, but if the wheel 14 is in a state of starting to descend from the step 90, the determination of S7 is YES. .

  After that, in S8, the step descending control mode is selected, and as shown in FIG. 4 (c), the motor 20 of the motor 20 is instantaneously increased to a value larger than that during normal running as shown in FIG. The drive signal is controlled. In this case, the tire pressing force by the motor 20 becomes stronger than during normal running. As a result, the force that separates the wheel 14 this time from the vehicle body 12 increases from that during normal travel. As a result, a large vertical movement does not occur in the vehicle body 12 relative to the height of the step 90 where the wheel 14 descends this time.

  Specifically, as shown in FIG. 4C, when the driving torque of the motor 20 that rotates the wheel 14 in the forward direction momentarily increases, the suspension arm 40 swings in the direction that moves the wheel 14 away from the vehicle body 12. The dynamic torque also increases instantaneously. Due to the instantaneous increase, the tire pressing force by which the motor 20 presses the tire of the wheel 14 against the road surface increases instantaneously. As a result, the wheel 14 is more easily separated from the vehicle body 12 than during normal travel, and the step (protrusion) 90 is increased. It becomes easy to follow the downhill slope of.

  Subsequently, in S9 in FIG. 3, detection signals are input from the arm angle sensor 84 and the motor speed sensor 86, and then in S10, the vibration of the current wheel 14 falls within the allowable range based on the input detection signals. It is determined whether or not it has converged. For example, the time variation of the angle of the suspension arm 40 detected by the arm angle sensor 84 is equal to or less than the reference value, and / or the time variation of the rotation speed of the motor 20 detected by the motor speed sensor 86 is equal to or less than the reference value. In this case, it is determined that the vibration of the wheel 14 has converged within the allowable range.

  If the vibration of the wheel 14 has converged within the allowable range, the determination in S10 is YES and the process proceeds to S3. If the vibration does not converge, the determination in S10 is NO and the process proceeds to S11. In S11, the drive torque is instantaneously decreased, and then in S12, the drive torque is instantaneously increased. It is desirable that the increase / decrease in the drive torque due to the execution of S11 and S12 be performed so as to be synchronized as much as possible with the current vertical movement of the wheel 14. As the drive torque increases or decreases, the current vibration of the wheel 14 is gradually attenuated. Thereby, even after the wheel 14 gets over the step 90, the phenomenon that the vehicle body 12 vibrates is suppressed.

  As a result of the execution of S9 to S12 being repeated several times, if the vibration of the current wheel 14 converges within the allowable range, the determination of S10 becomes YES, and after the execution of S3 and S4, Execution is completed.

  As is apparent from the above description, in the present embodiment, the drive gear 24 constitutes an example of the “first rotating body” in the item (1), and the driven gear 30 is the “second rotating body” in the same term. The suspension arm 40 constitutes an example of the “first coupling mechanism” in the same term, and the suspension spring 50 constitutes an example of the “second coupling mechanism” in the same term.

  Further, in the present embodiment, the wheel 14 shown in FIG. 1 constitutes an example of “non-steered wheel” in the item (5), and the controller 60 constitutes an example of “control device” in the item (7). The portion of the controller 60 that executes the step climbing control program shown in FIG. 3 constitutes an example of the “wheel drive torque control unit” in the item (9).

  Next, a second embodiment of the present invention will be described. FIG. 5 is a side view of the motor side as seen from the cross-section as AA in FIG. However, since this embodiment is different from the first embodiment only in mechanical configuration and has the same electrical configuration, only the mechanical configuration will be described, and the same reference numerals or names will be used for the electrical configuration. Therefore, the detailed description is omitted.

  In the first embodiment, the rotational torque of the motor 20 is transmitted to the wheel 14 by a gear train in which the drive gear 24 coaxial with the motor 20 is engaged with the driven gear 30 coaxial with the wheel 14. On the other hand, in the wheel support / drive device 110 according to the present embodiment, the rotational torque of the motor 20 is transmitted to the wheel 14 by the planetary gear mechanism 114 as shown in FIG.

  The planetary gear mechanism 114 is configured to include a sun gear 120, a plurality of pinion gears 122, 122, 122, a carrier 124, and a ring gear 126, as is well known. In the present embodiment, as shown in FIG. 5, the sun gear 120 is rotated coaxially with the wheel 14 and integrally therewith. The ring gear 126 is connected to a wheel on the outer periphery via a bearing or the like, and is rotated relative to the wheel 14. The sun gear 120 and the ring gear 126 rotate in opposite directions.

  The plurality of pinion gears 122, 122, 122 are arranged side by side along a circumference of the same axis as the sun gear 120. The pinion gears 122, 122, 122 are arranged so as to mesh with the sun gear 120 on the outer tooth surface 130 thereof and with the ring gear 126 on the inner tooth surface 132 thereof. The plurality of pinion gears 122, 122, 122 are held by the carrier 124 so that the relative positional relationship between the rotation centers of the plurality of pinion gears 122, 122, 122 is maintained.

  One of the plurality of pinion gears 122, 122, 122 is selected as the input pinion 140, and the motor 20 is coaxially connected to the input pinion 140. A relative angular displacement does not occur between the input pinion 140 and the motor 20, and the motor 20 is supported by the vehicle body 12 so as not to move at least in the vertical direction. Although relative angular displacement does not occur between the input pinion 140 and the carrier 124, the carrier 124 is supported so as to be able to reciprocally swing along with the wheels 14 with the rotation center of the motor 20 and the input pinion 140 as the swing center.

  As shown in FIG. 5, the suspension spring 50 elastically acts on the vehicle body 12 and the wheel 14 (for example, the rotating shaft 144 of the sun gear 120 and the portion of the suspension arm 40 that reciprocally swings as the wheel 14 reciprocates). Connected to each other.

  The wheel 14 is reciprocally swung around the rotation center of the motor 20, that is, the rotation center of the input pinion 140. By the reciprocating swing, the vertical movement of the wheel 14 relative to the vehicle body 12 is realized. In the present embodiment, the suspension arm 40 and the suspension spring 50 jointly constitute the suspension 150 of the wheel 14.

  Since the oscillation center of the wheel 14 coincides with the rotation center of the motor 20, that is, the rotation center of the input pinion 140, these rotation centers function as the operation center of the suspension 150. As the wheel 14 swings, the suspension arm 40 selects from the neutral position shown in FIG. 5 between the direction in which the wheel 14 approaches the vehicle body 12 and the direction in which the wheel 14 moves away from the vehicle body 12. The range of the rotation angle means the operating range of the suspension 150.

  In FIG. 6, the wheel support / drive device 110 is shown in a front view with respect to a wheel 14 that is a steered wheel among steered wheels and non-steered wheels in a vehicle. However, the wheel 14 and the ring gear 126 are shown in a vertical sectional view including the rotation center shaft 34 of the wheel 14. Therefore, in the wheel support / drive device 110 shown in FIG. 6, the motor 20 is attached to the frame 160 fixed to the vehicle body 12 so as not to be movable in the vertical direction, but generally around the rotation axis S extending in the vertical direction. It is pivotally attached. By this rotation, the wheel 14 is swung in the horizontal plane, that is, steered, and thus the vehicle is steered. That is, the rotation axis S means the steering center of the wheel 14.

FIG. 7 is a plan view of the wheel support / drive device 110 shown in FIG. FIG. 8A shows a schematic plan view of the same wheel support / drive device 110 when the vehicle is turning right, and FIG. 8B shows the vehicle when turning left. However, the wheel 14 and the ring gear 126 are shown in a horizontal sectional view including the rotation center shaft 34 of the wheel 14.

  Therefore, in the present embodiment, when the wheel 14 is bound and rebound, the wheel 14 is moved up and down leaving the motor 20 and the input pinion 140, while when the wheel 14 is steered, the wheel 14 is moved to the motor 20 and the input pinion 140. And is rotated in a horizontal plane.

  As is clear from the above description, in the present embodiment, the input pinion 140 constitutes an example of the “first rotating body” in the item (1), and the sun gear 120 corresponds to the “second rotating body” in the same term. The suspension arm 40 constitutes an example of the “first coupling mechanism” in the same term, and the suspension spring 50 constitutes an example of the “second coupling mechanism” in the same term.

  Further, in the present embodiment, the wheel 14 constitutes an example of “steering wheel” in the item (6), and the motor 20 and the input pinion 140 constitute an example of “motor and first rotating body” in the same term. It is doing.

  As another embodiment, the planetary gear mechanism 114 may rotate the sun gear 120 relative to the wheel 14 and rotate the ring gear 126 integrally with the wheel 14. The driving force of the motor 20 is transmitted from the input pinion 140 to the wheel and the wheel 14 via the ring gear 126. Since the sun gear 120 runs idle, the sun gear 120 and the rotation center shaft 34 of the wheel 14 or the wheel 14 and the rotation center shaft 34 of the wheel 14 may be connected via a bearing or the like.

In this embodiment, the input pinion 140 constitutes an example of the “first rotating body” in the above item (1), and the ring gear 126 constitutes an example of the “second rotating body” in the same term.

  Next, a third embodiment of the present invention will be described. However, since this embodiment is different from the second embodiment only in mechanical configuration and has the same electrical configuration, only the mechanical configuration will be described, and the same reference numerals or names will be used for the electrical configuration. Therefore, the detailed description is omitted.

  9 to 11 show a wheel support / drive device 200 according to the present embodiment in a side view, a front view, and a plan view, respectively. However, FIG. 9 is a side view of the motor side as viewed from the cross-section as shown by BB in FIG. Further, the wheel 14 and the ring gear 226 in FIG. 10 are shown in a vertical sectional view including the rotation center axis 34 of the wheel 14, and the wheel 14 and the ring gear 226 in FIG. 11 are illustrated in a horizontal sectional view including the rotation center axis 34 of the wheel 14. It shows with.

  As shown in FIG. 9, the wheel 14 is configured by mounting a rubber tire 218 on the outside of a steel wheel 216. Air is sealed in the tire 218 under pressure.

  As shown in FIG. 10, a planetary gear mechanism 214 is arranged inside the wheel 216. Further, a part of the axial dimension of the motor 20, that is, an end portion close to the planetary gear mechanism 214 among both end portions of the housing of the motor 20 is also arranged inside the wheel 216. Therefore, it is easier to shorten the overall axial dimension of the motor 20 and the wheel 216 than when the entire axial dimension of the motor 20 is disposed outside the wheel 216.

  As shown in FIG. 9, the planetary gear mechanism 214 is configured to include a sun gear 220, a plurality of pinion gears 222, 222, 222, a carrier 224, and a ring gear 226, as in the second embodiment. . The sun gear 220 is rotated coaxially with the wheel 14 and integrally therewith. The ring gear 226 is connected to the wheel 216 on the outer periphery via a bearing or the like, and is rotated relative to the wheel 14. The sun gear 220 and the ring gear 226 rotate in opposite directions.

  The plurality of pinion gears 222, 222, 222 are arranged side by side along a circumference of the same axis as the sun gear 220, and mesh with the sun gear 220 at the outer tooth surface 230, while the ring gear 226 is inside thereof. It arrange | positions so that it may mesh in the tooth surface 232. FIG. The plurality of pinion gears 222, 222, 222 are held by a carrier 224.

  One of the plurality of pinion gears 222, 222, 222 is an input pinion 240 and is coaxially connected to the motor 20. No relative angular displacement occurs between the input pinion 240 and the motor 20, and the motor 20 is supported by the vehicle body 12 so as not to move at least in the vertical direction. Although relative angular displacement does not occur between the input pinion 240 and the carrier 224, the carrier 224 is supported so as to be capable of reciprocatingly swinging with the wheel 14 about the rotation shaft 32 of the motor 20 and the input pinion 240. .

  As shown in FIG. 9, the suspension spring 50 is a part of the vehicle body 12 and the wheel 14 (for example, the rotating shaft 244 of the sun gear 220, the part of the suspension arm 210 that will be described later in detail) Are elastically connected to each other.

  The wheel 14 is reciprocally swung around the rotation center of the motor 20, that is, the rotation center of the input pinion 240. By the reciprocating swing, the vertical movement of the wheel 14 relative to the vehicle body 12 is realized. In the present embodiment, the suspension arm 210 and the suspension spring 50 jointly constitute the suspension 250 of the wheel 14.

  Since the oscillation center of the wheel 14 coincides with the rotation center of the motor 20, that is, the rotation center of the input pinion 240, these rotation centers function as the operation center of the suspension 250. As the wheel 14 swings, the suspension arm 210 selects the direction in which the wheel 14 approaches the vehicle body 12 and the direction in which the wheel 14 moves away from the vehicle body 12 from the neutral position shown in FIG. Can be rotated.

  In FIG. 10, the wheel support / drive device 200 is shown in a front view with respect to a wheel 14 that is a steered wheel among steered wheels and non-steered wheels in a vehicle. In the wheel support / drive device 200 shown in the figure, the motor 20 is attached to a frame 260 fixed to the vehicle body 12 so as not to be movable in the vertical direction, and around the rotation axis S extending generally in the vertical direction, A pivot shaft 262 extending generally vertically is pivotally mounted. By this rotation, the wheel 14 is swung in the horizontal plane, that is, steered, and thus the vehicle is steered.

  As shown in FIG. 10, the pair of suspension arms 210 and 210 are opposed to each other with a gap in the direction of the rotation axis of the motor 20 so as to sandwich the motor 20 and the planetary gear mechanism 214.

  Specifically, the rotation shaft 264 is coaxially penetrated across the motor 20 and the input pinion 240, and a pair of suspension arms 210 and 210 are spanned between the rotation shaft 264 and the rotation shaft 244 of the sun gear 220. ing. One suspension arm 210 (shown on the left side in FIG. 10) includes an end projecting from the motor 20 on the opposite side of the wheel 14 from both ends of the rotating shaft 264, and a sun gear 220 among the both ends of the rotating shaft 244. The end portions protruding to the opposite side from the wheel 14 are connected to each other so as to be rotatable with the distance unchanged. The other suspension arm 210 (shown on the right side in FIG. 10) includes an end protruding from the input pinion 240 to the opposite side of the motor 20 from both ends of the rotating shaft 264 and a sun gear among the both ends of the rotating shaft 244. The end portion that protrudes from 220 to the opposite side of the motor 20 is rotatably connected with the distance unchanged.

  The features of the present embodiment will be described in comparison with the second embodiment described above. In the second embodiment, as shown in FIG. 6, the rotational torque of the motor 20 is transmitted to the wheels 14 by the planetary gear mechanism 114. Is done. In the second embodiment, the rotating shaft 22 of the motor 20 and the rotating shaft 32 of the input pinion 140 (the rotating shafts 22 and 32 are configured integrally with each other) and the rotating shaft 144 of the sun gear 120 are provided. The suspension arms 40 and 40 are connected to each other.

  In the second embodiment, as shown in FIG. 6, the suspension arms 40 and 40 are disposed together in a space between the wheel 14 and the motor 20. On the other hand, in the wheel support / drive device 200 according to the present embodiment, as shown in a front view in FIG. 10, a pair of suspension arms 210, 210 are a planetary gear mechanism in which the motor 20 and the wheel 14 are disposed. It is arranged so as to sandwich 214.

  Therefore, according to the present embodiment, the suspension arms 210 and 210 are arranged in the axial direction of the two rotation shafts 244 and 264 that are parallel to each other to be connected to each other between the motor 20 and the input pinion 240 and the sun gear 220. They will be opposed to each other with a longer distance than in the second embodiment.

  Therefore, according to the present embodiment, the suspension arms 210, 264 are connected to each other in order to connect the two rotary shafts 244 and 264 to each other so that the distance and the parallelism between the two rotary shafts 244 and 264 are maintained. It is not necessary to increase the individual rigidity and thickness of 210 as much as the suspension arms 40 and 40 in the second embodiment.

  In the second embodiment, as shown in FIG. 6, the entire motor 20 is disposed outside the wheel 14. On the other hand, in this embodiment, as shown in FIG. 10, at least a part of the motor 20 in the axial direction is disposed inside the wheel 14.

  Therefore, according to the present embodiment, it is easy to arrange the motor 20 and the wheels 14 in the vehicle more compactly than the second embodiment, and the wheel support / drive device 200 can be easily reduced in size and weight. Further, according to the present embodiment, it is easy to bring the turning axis S of the wheel 14 that is a steered wheel, that is, the steering center (kingpin axis) closer to the wheel 14.

  As is clear from the above description, in the present embodiment, the input pinion 240 constitutes an example of the “first rotating body” in the item (1), and the sun gear 220 corresponds to the “second rotating body” in the same term. A pair of suspension arms 210 and 210 constitute an example of the “first coupling mechanism” in the same paragraph, and the suspension spring 50 constitutes an example of the “second coupling mechanism” in the same paragraph. .

  Further, in the present embodiment, the wheel 14 constitutes an example of “steering wheel” in the item (6), and the motor 20 and the input pinion 240 constitute an example of “motor and first rotating body” in the same term. It is doing.

  As another embodiment, the planetary gear mechanism 214 may rotate the sun gear 220 relative to the wheel 14 and rotate the ring gear 226 integrally with the wheel 14. The driving force of the motor 20 is transmitted from the input pinion 240 to the wheel 14 via the ring gear 226. Since the sun gear 220 runs idle, the sun gear 220 and the rotating shaft 244 or the wheel 14 and the rotating shaft 244 may be connected via a bearing or the like.

In this embodiment, the input pinion 240 constitutes an example of the “first rotating body” in the above item (1), and the ring gear 226 constitutes an example of the “second rotating body” in the same term.

  In addition, any of the embodiments described above can be changed to a mode in which the displacement speed in the vertical direction of the wheel 14, that is, the vertical stroke speed is detected by the sensor while the vehicle is running. The vertical stroke speed can be detected, for example, using an arm angle sensor 84 and as a time differential value of an angle detected by the arm angle sensor 84.

  In this aspect, the controller 60 controls the drive signal of the motor 20 so that the output torque of the motor 20 and thus the drive torque of the wheels 14 are controlled based on the detected vertical stroke speed. If this aspect is adopted, the damping characteristics of the suspensions 52, 150, and 250 can be variably controlled by the motor 20 that rotationally drives the wheels 14 for vehicle travel.

  As described above, some of the embodiments of the present invention have been described in detail with reference to the drawings. However, these are merely examples, and the knowledge of those skilled in the art including the aspects described in the above [Disclosure of the Invention] section. It is possible to implement the present invention in other forms in which various modifications and improvements are made based on the above.

It is a side view which shows the mechanical structure of the wheel support and drive device 10 according to 1st Embodiment of this invention. It is a block diagram which shows the electric constitution of the wheel support and drive device 10 shown in FIG. 3 is a flowchart conceptually showing a step difference control program stored in a ROM 66 in FIG. It is the table | surface and side view for demonstrating the level | step difference control program shown in FIG. 3 for every control mode. It is a side view which shows the mechanical structure of the wheel support and drive device 110 according to 2nd Embodiment of this invention. It is a front view which shows the wheel support and drive device 110 shown in FIG. It is a top view which shows the wheel support and drive device 110 shown in FIG. It is a top view for demonstrating the steering state of the vehicle by which the wheel support and drive device 110 shown in FIG. 5 is mounted. It is a side view which shows the mechanical structure of the wheel support and drive device 200 according to 3rd Embodiment of this invention. It is a front view which shows the wheel support and drive device 200 shown in FIG. It is a top view which shows the wheel support and drive device 200 shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wheel support / drive device 12 Car body 14 Wheel 20 Motor 24 Drive gear 30 Driven gear 40 Suspension arm 50 Suspension spring 52 Suspension 60 Controller 90 Step 110 Wheel support / drive device 114 Planetary gear mechanism 120 Sun gear 122 Pinion gear 124 Carrier 126 Ring gear 150 Suspension 200 Wheel support / drive device 210 Suspension arm 214 Planetary gear mechanism 220 Sun gear 222 Pinion gear 224 Carrier 226 Ring gear 250 Suspension

Claims (10)

A wheel support / drive device that is provided in a vehicle and supports the wheel so as to be movable up and down with respect to the vehicle body.
A motor supported by the vehicle body and a first rotating body rotated by the motor;
A second rotating body that is coaxially and integrally rotated with the wheel;
A first connecting mechanism that connects the first rotating body and the rotation center axis of the wheel to each other in a state where the wheel can reciprocally swing around the center of rotation of the first rotating body. When,
A wheel support / drive device comprising: a second connection mechanism that elastically connects the wheel and the vehicle body to each other;
The wheel support / drive device according to claim 1, wherein the first rotating body is rotated by the motor around a rotation center decentered from a rotation center of the wheel in a direction intersecting a vertical direction. The first rotating body is a drive gear;
The second rotating body is a driven gear that meshes with the drive gear and is rotated.
The first coupling mechanism includes a suspension arm that couples the driven gear and the driven gear to each other in an engaged state in a state where the driven gear has a constant radius around the drive gear and can swing back and forth.
The wheel support / drive device according to claim 1, wherein the second connection mechanism includes a suspension spring that elastically connects the wheel and the vehicle body to each other. A sun gear that is coaxially and integrally rotated with the wheel;
A ring gear that is coaxial with and rotated relative to the wheel;
A plurality of pinion gears arranged side by side along a circumference of the same axis as the sun gear, the sun gear meshing with its outer tooth surface, and the ring gear meshing with its inner tooth surface;
A carrier that holds the plurality of pinion gears so that the relative positional relationship between the rotation centers of the plurality of pinion gears is maintained, and a planetary gear mechanism is configured by the sun gear, the ring gear, the plurality of pinion gears, and the carrier,
The first rotating body is configured as one of the plurality of pinion gears,
The wheel support / drive device according to claim 1, wherein the second rotating body is configured as the sun gear. A sun gear that is coaxial with the wheel and rotated relative thereto;
A ring gear that is coaxially and integrally rotated with the wheel;
A plurality of pinion gears arranged side by side along a circumference of the same axis as the sun gear, the sun gear meshing with its outer tooth surface, and the ring gear meshing with its inner tooth surface;
A carrier that holds the plurality of pinion gears so that the relative positional relationship between the rotation centers of the plurality of pinion gears is maintained, and a planetary gear mechanism is configured by the sun gear, the ring gear, the plurality of pinion gears, and the carrier,
The first rotating body is configured as one of the plurality of pinion gears,
The wheel support / drive device according to claim 1, wherein the second rotating body is configured as the ring gear.   The wheel support / drive device according to any one of claims 1 to 4, wherein the motor is coaxially connected to the first rotating body. The wheels are non-steered wheels that are not steered during steering of the vehicle;
The wheel support / drive device according to claim 1, wherein the motor and the first rotating body are supported by the vehicle body at fixed positions. The wheels are steered wheels that are steered during steering of the vehicle;
The wheel support according to any one of claims 1 to 5, wherein the motor and the first rotating body are supported by the vehicle body so as to be rotated integrally with the steered wheel during steering of the vehicle. Drive device.   The wheel support / drive device according to any one of claims 1 to 7, further comprising a control device that controls an output torque of the motor by controlling a drive signal to the motor.   The control device includes a damping characteristic control unit that controls a damping characteristic in a vertical movement of the wheel with respect to the vehicle body by controlling a swing characteristic of the wheel about the swing center through the motor. 8. The wheel support / drive device according to 8.   The wheel support / drive device according to claim 8 or 9, wherein the control device includes a wheel drive torque control unit that controls a drive torque around a rotation center of the wheel via the motor.

Images