JP2013124016A - Wheel drive device - Google Patents

Abstract

To provide a wheel drive device that can be downsized by including a lock mechanism that securely locks a wheel when the vehicle is stopped.
A wheel drive device includes an in-wheel motor (that is, a motor body) and a planetary gear reducer. Further, the device 10 includes a lock mechanism 40. The lock mechanism 40 is housed inside the hollow output shaft 16a of the motor main body 16, and includes an engagement member 41 and a shaft 16a that are non-rotatably assembled to the motor housing 17 via the actuator 42. And an engaging member 43 integrally assembled on the peripheral surface. Furthermore, the apparatus 10 includes a malfunction prevention mechanism 44 that permits the engagement of the members 41 and 43 only when the vehicle is stopped between the members 41 and 43. The prevention mechanism 44 prohibits displacement of the member 41 to the member 43 during traveling by the shielding plate 44b that is displaced in the radial direction by centrifugal force generated during traveling.
[Selection] Figure 1

Description

  The present invention relates to a wheel drive device that transmits an output from a drive source to a wheel via a drive force transmission mechanism.

  Conventionally, a wheel drive device having an in-wheel motor has been actively proposed. For example, in Patent Document 1 described below, the rotational force of a motor disposed in a wheel is decelerated by a plurality of speed reducers and transmitted to the wheel so that the wheel can be driven. A wheel drive device is disclosed in which a motor is disposed between second reduction gears, and a drive shaft of the motor and an output shaft of each reduction gear are arranged in parallel.

  Conventionally, for example, in Patent Document 2 below, in addition to a side brake operated when the vehicle is stopped, a lock mechanism for stopping rotation with respect to a rotating shaft of a motor used in an in-wheel motor system can be engaged and disengaged. An electric vehicle drive device provided is shown. The lock mechanism provided in the drive device of this conventional electric vehicle includes a plurality of engagement grooves formed on the outer peripheral surface of the rotating shaft of the motor, and a relative rotation with respect to the rotating shaft and advancing from the end side of the rotating shaft. And a locking body provided so as to be able to move backward and engaging with the engaging groove.

JP 2008-184111 A JP 2002-186115 A

  By the way, the lock mechanism provided in the drive device of the conventional electric vehicle can be engaged and disengaged, and the locking body is advanced and retracted from the end side of the rotating shaft of the motor. For this reason, it is necessary to secure an installation space for the lock mechanism and a space for engaging and disengaging the lock mechanism in the axial direction of the drive shaft and the rotary shaft constituting the wheel drive device, which hinders downsizing of the wheel drive device. there is a possibility.

  The present invention has been made to address the above-described problems, and an object of the present invention is to provide a wheel drive device that can be miniaturized with a lock mechanism that securely locks the wheels when the vehicle is stopped. .

  In order to achieve the above object, a feature of the present invention is provided with a drive source that generates a drive force for driving a wheel of a vehicle, and a drive force transmission mechanism that transmits an output from the drive source to the wheel. In the above wheel drive device, at least one rotating shaft constituting the driving force transmission mechanism is formed in a hollow shape, and a lock mechanism for locking the rotation of the wheel is provided in the hollow portion. Here, as the driving source, for example, an in-wheel motor that is provided in a wheel forming the wheel and generates a driving force can be employed. According to this, the lock mechanism for locking the rotation of the wheel when the vehicle is stopped can be provided in the hollow portion of the rotating shaft constituting the driving force transmission mechanism. Thereby, it is not necessary to secure a space for providing the lock mechanism separately, and it is possible to reduce the size of the wheel drive device particularly when an in-wheel motor is employed.

  In this case, the locking mechanism includes a locking means fixed to the vehicle body side of the vehicle so as not to rotate, an engaging means that rotates integrally with the rotating body and engages with the locking means, and the locking mechanism The means can be composed of advancing and retracting means for advancing and retracting the engaging means. In this case, as the engagement between the locking means and the engaging means, for example, mechanical engagement such as spline fitting, friction engagement using a friction member, or electromagnetic engagement Engagement using force can be employed. Thereby, a very simplified configuration can be adopted, and in a state where the locking means and the engaging means are engaged with each other, the rotation of the wheel can be reliably locked (stopped).

  In these cases, a malfunction prevention mechanism that prevents the lock mechanism from operating when the wheel is rotating can be further provided. The malfunction prevention mechanism is operated in accordance with the rotation of the wheel to prevent the lock mechanism from being operated. For example, the malfunction prevention mechanism is operated by a centrifugal force generated in association with the rotation of the wheel to This prevents operation. More specifically, the malfunction prevention mechanism has an insertion hole through which the locking means that advances and retreats by the advance / retreat means, and the locking means passes through the insertion hole when the vehicle is stopped. When the vehicle is running, it is displaced in the radial direction of the insertion hole by the generated centrifugal force, and the locking means is moved through the insertion hole. Shielding means for prohibiting movement to the engaging means can be provided. According to these, when the vehicle travels, it is possible to reliably prevent (prohibit) the malfunction of the operation of the lock mechanism, for example, the erroneous engagement between the locking means and the engaging means. Only at times can the lock mechanism be properly actuated to lock (still) the rotation of the wheel.

  In these cases, the driving force transmission mechanism can be constituted by a speed reducer that decelerates the output from the driving source and transmits it to the wheels. Specifically, the reduction gear is engaged with, for example, a sun gear that receives an output from the drive source, a ring gear that is fixed to the vehicle body side, and the sun gear and the ring gear. A plurality of planetary gears revolving around the vehicle and a planetary carrier disposed outside the vehicle and fixed to carrier pins of the plurality of planetary gears. In this case, the lock mechanism can be provided, for example, in the hollow portion of the input shaft that inputs the output from the drive source to the speed reducer. According to these, when the lock mechanism generates a rotation stopping force necessary to lock (stop) the rotation of the wheel, the deceleration effect by the reduction gear can be effectively used. As a result, the necessary anti-rotation force can be reduced, and as a result, for example, the required strength and the like can be suppressed and the lock mechanism can be reduced in size and weight.

It is the schematic which shows the cross-section of the wheel drive device which concerns on one Embodiment of this invention. It is sectional drawing expanded and shown in order to demonstrate the structure of the planetary gear speed reducer of FIG. FIG. 2 is an enlarged cross-sectional view illustrating the structure of the lock mechanism of FIG. 1. It is sectional drawing for demonstrating the action | operation of the lock mechanism (more specifically, malfunction prevention mechanism) at the time of a vehicle stop. It is sectional drawing for demonstrating the action | operation of the lock mechanism (more specifically, malfunction prevention mechanism) at the time of vehicle travel. It is sectional drawing for demonstrating the structure of the malfunction prevention mechanism which concerns on the modification of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows a cross-sectional structure of a wheel drive device 10 that employs a so-called in-wheel motor system that has an electric motor for each wheel according to an embodiment of the present invention.

  The wheel drive device 10 includes an in-wheel motor 13 on the inner peripheral side of the wheel 12 on which the tire 11 is mounted. The in-wheel motor 13 is connected via a knuckle 14 to a lower arm, an upper arm, and a tie rod (not shown) that constitute a vehicle suspension mechanism. The wheel drive device 10 also includes a brake disc rotor 15 that constitutes a brake device (for example, a disc brake device). The brake disc rotor 15 is clamped by a brake caliper (not shown) to be controlled by friction. Generate power.

  As shown in FIG. 1, the in-wheel motor 13 includes a motor main body 16 and a cylindrical motor housing 17 that is integrally connected to the knuckle 14 on the vehicle body side and accommodates the motor main body 16. The motor body 16 has a hollow output shaft 16a rotatably supported by a bearing, and a plurality of permanent magnets fixed to the outer periphery of the electromagnetic steel plates 16b stacked on the outer peripheral surface side of the output shaft 16a. A rotor 16d made of a magnet 16c is inserted. On the outer periphery of the rotor 16d, an iron core 16e formed of laminated electromagnetic steel sheets, and a coil 16f wound around a three-phase coil slot wound around each tooth portion formed on the iron core 16e, The stator 16g comprised from these is arrange | positioned. The rotor 16d and the stator 16g face each other through a predetermined gap and are hermetically sealed by the motor housing 17 so that entry of foreign matter from the outside is prevented. In the motor body 16 configured in this manner, a rotating magnetic field can be generated in the stator 16g and the rotor 16d can be rotated by sequentially supplying current to the coil 16f at a predetermined timing.

  Moreover, the wheel drive device 10 according to the present embodiment includes a planetary gear speed reducer 20 as a drive force transmission mechanism that transmits the drive force of the in-wheel motor 13 to the wheels. The planetary gear speed reducer 20 is a two-stage arranged on the front end side of the output shaft 16a of the motor main body 16 (that is, the in-wheel motor 13), in other words, the input shaft that inputs the output of the motor main body 16 to the speed reducer 20. Planetary gear mechanisms 21 and 22. In the present embodiment, the planetary gear speed reducer 20 is configured with the two-stage planetary gear mechanisms 21 and 22, but depending on the required reduction ratio, the one-stage planetary gear mechanism or three or more stages are used. It goes without saying that the planetary gear speed reducer 20 can be constructed from the planetary gear mechanism.

  The first sun gear 21a of the first stage planetary gear mechanism 21 forming the planetary gear speed reducer 20 is, as shown in FIG. 2, the tip of the output shaft 16a (that is, the input shaft) of the motor main body 16 constituting the in-wheel motor 13. It is formed integrally with the part. The first sun gear 21a meshes with a plurality (only one is shown in FIG. 2) of the first planetary gears 21b, and the plurality of first planetary gears 21b is further fixed to the knuckle 14. The first ring gear 21c formed even on the inner peripheral surface of the held inner ring side member 23 is engaged with the first ring gear 21c. Thereby, each of the plurality of first planetary gears 21b revolves around the first sun gear 21a. The first sun gear 21a, the plurality of first planetary gears 21b, and the first ring gear 21c that constitute the planetary gear mechanism 21 are helical gears that can receive a thrust load in the axle direction.

  The first carrier pin 21d that rotatably supports the plurality of first planetary gears 21b is fixed to the first planetary carrier 21e, and the revolving motion of the first stage planetary gear mechanism 21 is the second stage planetary gear. It is transmitted to the mechanism 22. Specifically, a shaft 21f extending coaxially with the axle is connected to the center of the first planetary carrier 21e of the planetary gear mechanism 21, and the second sun gear 22a of the planetary gear mechanism 22 is integrally formed with the shaft 21f. Yes. The shaft 21f is pivotally supported by a bearing. The second sun gear 22a meshes with a plurality (only one is shown in FIG. 2) of second planetary gears 22b, and the plurality of second planetary gears 22b is further connected to the inner ring side member 23. It meshes with the second ring gear 22c formed on the peripheral surface. Thereby, each of the plurality of second planetary gears 22b revolves around the second sun gear 22a. The second sun gear 22a, the plurality of second planetary gears 22b, and the second ring gear 22c that constitute the planetary gear mechanism 22 are helical gears that can receive a thrust load in the axle direction.

  Here, the number of second planetary gears 22b that mesh with the second sun gear 22a is equal to, for example, the number of bolt holes (mounting holes) formed in the wheel 12, and the bolt holes formed in the wheel 12 are the same. It corresponds to the arrangement of (mounting holes). Further, the radius of a circle circumscribing a polygon formed by connecting the centers of the plurality of second planetary gears 22b arranged around the second sun gear 22a (that is, the center of a second carrier pin 22d described later) is P. of wheel 12 C. It matches D (Pitch Circle Diameter).

  A second carrier pin 22d that rotatably supports the plurality of second planetary gears 22b is fixed to a second planetary carrier 22e that is a power transmission member. As shown in FIG. 2, the plurality of second carrier pins 22d are formed to extend outward from the vehicle in the axle direction, and pass through the second planetary carrier 22e. A threaded portion 22d1 that is screwed to a wheel nut for fixing the wheel 12 to the axle is formed at the extended end of the plurality of second carrier pins 22d. That is, a portion of the second carrier pin 22d that protrudes from the second planetary carrier 22e to the vehicle outer side in the axle direction (a tip side portion) is formed with a bolt that functions as a so-called hub bolt. Here, since the second carrier pin 22d supports the second planetary gear 22b, the arrangement of the bolt holes (mounting holes) of the wheel 12 and the P.P. C. By disposing the second planetary gear 22b so as to coincide with D, the distal end side portion (that is, the hub bolt portion) of the second carrier pin 22d ensures the general-purpose wheel 12 together with the wheel nut with respect to the axle. Can be fixed.

  An axle bearing 30 is disposed on the outer periphery of the planetary gear speed reducer 20. As shown in FIG. 2, the axle bearing 30 includes an inner race 31 formed on a substantially cylindrical inner ring side member 23 having a flange portion 23 a fixed to the knuckle 14 at one end, and an inner peripheral surface of the outer ring side member 32. The outer race 33 is formed mainly by a bearing ball 34 that rolls in a rolling path defined by the inner race 31 and the outer race 33. By this axle bearing 30, the outer ring side member 32 is rotatably held with respect to the inner ring side member 23. The inner race 31 and the outer race 33 of the axle bearing 30 are not integrated with the inner ring side member 23 and the outer ring side member 32, and the inner race and outer race of different parts are fixed to the inner ring side member 23 or the outer ring side member 32. You may make it do. Although not shown, the axle bearing 30 is provided with a seal member so that foreign matter does not enter the rolling path.

  As shown in FIG. 2, the outer ring side member 32 is integrally connected to the second planetary carrier 22 e constituting the planetary gear mechanism 22 of the planetary gear speed reducer 20 by, for example, bolt fastening or caulking fastening, The second planetary carrier 22e is supported so as to rotate stably. Here, by connecting the second planetary carrier 22e and the outer ring side member 32 integrally, that is, without rattling, the rotational driving force by the in-wheel motor 13 is transmitted and the second planetary carrier 22e is transmitted. And the outer ring side member 32 can be effectively prevented from generating abnormal noise (rattle noise) when starting to rotate. Then, the wheel 12 is screwed by screwing the wheel nut in a state where the tip side portion (that is, the hub bolt portion) of the second carrier pin 22d that is integrally connected is inserted into the bolt hole (mounting hole) of the wheel 12. It can be securely fixed to the axle.

  Here, the operation of the wheel driving device 10 configured as described above, more specifically, the transmission path of the driving force as the output generated by the in-wheel motor 13 will be described.

  For example, when the driver operates the accelerator pedal of the vehicle to give an acceleration instruction, the in-wheel motor 13, more specifically, the motor body 16 starts to rotate in response to a command from a vehicle control device (not shown). Drive power. That is, in the motor body 16, the rotor 16d rotates with respect to the stator 16g, and this rotational driving force is transmitted to the planetary gear speed reducer 20 via the output shaft 16a (that is, the input shaft constituting a part of the driving force transmission mechanism). Is transmitted to. In the planetary gear mechanism 21 of the planetary gear reducer 20, the rotation is transmitted to the plurality of first planetary gears 21b via the first sun gear 21a formed integrally with the output shaft 16a, so that the planetary gear mechanism 21 is fixed to the knuckle 14. The first planetary gear 21b that meshes with the first ring gear 21c, which rotates, revolves around the first sun gear 21a while rotating. The revolving motion of the first planetary gear 21b is taken out by the first planetary carrier 21e connected via the first carrier pin 21d, and the shaft 21f connected to the first planetary carrier 21e is integrally rotated. .

  When the shaft 21f rotates integrally by the revolving motion of the first planetary gear 21b, the rotation of the shaft 21f is transmitted to the planetary gear mechanism 22. That is, in the planetary gear mechanism 22, the rotation is transmitted to the plurality of second planetary gears 22b via the second sun gear 22a formed integrally with the shaft 21f (input shaft). As a result, the second planetary gear 22b meshing with the second ring gear 22c fixed to the knuckle 14 revolves around the second sun gear 22a while rotating. The revolving motion of the second planetary gear 22b is directly applied to the second planetary carrier 22e, the outer wheel side member 32 of the axle bearing 30, the brake disk rotor 15 of the brake device, the wheel 12 and the tire 11 via the second carrier pin 22d. As a result, the wheels are driven.

  On the other hand, the outer ring side member 32 of the axle bearing 30, the brake disc rotor 15, the wheel 12, and the tire 11 are integrally rotated by the driving force being transmitted from the in-wheel motor 13 according to the transmission path described above. Therefore, when the brake caliper of the brake device presses against the brake disc rotor 15 rotating the brake pad, when the brake pad integrally fixed to the vehicle body and the brake disc rotor 15 are frictionally engaged, A frictional force (braking force) due to the frictional engagement is transmitted to the wheel 12 and the tire 11, and as a result, the wheel is braked.

  Moreover, the wheel drive device 10 in this embodiment is provided with the lock mechanism 40 which locks a wheel, when the vehicle has stopped, as shown in FIG. As shown in detail in an enlarged view in FIG. 3, the lock mechanism 40 in the present embodiment is an output shaft 16a formed in a hollow shape of the motor body 16, that is, one of the planetary gear speed reducers 20 that is a driving force transmission mechanism. Are housed in a hollow input shaft (rotating shaft) that constitutes a portion, a locking member 41 as a locking means, an actuator 42 as an advancing / retreating means, and an engaging member 43 as an engaging means, It has.

  As shown in FIG. 3, the locking member 41 is assembled to the motor housing 17 fixed to the vehicle body via an actuator 42. And on the outer peripheral surface of the locking member 41 in the present embodiment, for example, a plurality of external teeth formed in a gear shape are formed. The actuator 42 includes, for example, a solenoid as a main component, and is fixed to the motor housing 17 whose one end is fixed to the vehicle body side so as not to rotate, and a locking member 41 is integrally formed with the other end. It is assembled. Thereby, for example, when a predetermined positive current is supplied, the actuator 42 expands and advances the locking member 41 to engage with the engaging member 43 in the axial direction of the output shaft 16a. When a negative current is supplied, the locking member 41 is reduced and retracted so as to be separated from the engaging member 43. Further, for example, the actuator 42 stops at the position when the supply of a predetermined current is cut off, so that the power consumption when the vehicle is stopped can be prevented. As shown in FIG. 3, the engaging member 43 is integrally fixed to the inner peripheral surface of the output shaft 16a. On the inner peripheral surface of the engagement member 43, for example, a plurality of internal teeth formed in a gear shape are formed so as to be able to mesh with the external teeth formed on the outer peripheral surface of the locking member 41. Has been.

  The locking mechanism 40 allows the locking member 41 that has advanced with the extension operation of the actuator 42 to engage with the engaging member 43 when the vehicle is stopped, while the vehicle is running. Even if the locking member 41 moves forward with the extension operation of the actuator 42, a malfunction prevention mechanism 44 that prevents (inhibits) the engagement between the locking member 41 and the engagement member 43 is provided. Yes. As shown in FIG. 3, the malfunction prevention mechanism 44 is accommodated in the output shaft 16 a (input shaft) of the motor body 16, and is disposed between the locking member 41 and the engaging member 43.

  As shown in FIGS. 3 to 5, the malfunction prevention mechanism 44 in this embodiment includes a casing 44a, a shielding plate 44b as shielding means, and a spring 44c. The casing 44a is formed in an annular shape, the outer peripheral surface side is integrally fixed to the inner peripheral surface of the output shaft 16a, and the shielding plate 44b can be displaced in the radial direction on the inner peripheral surface side. It is housed in the circumferential direction so that it cannot be displaced. As shown in FIGS. 3 and 4, the shielding plate 44 b is formed with an insertion hole 44 b 1 having an inner diameter slightly larger than the outer diameter of the locking member 41 at a substantially central portion thereof. Further, as shown in FIGS. 3 to 5, the shielding plate 44b includes, for example, a protrusion 44b2 and a protrusion 44b3 that extend radially outward on the diameter of the insertion hole 44b1. The projecting portion 44b2 and the projecting portion 44b3 are accommodated in the housing portion 44a1 and the housing portion 44a2 formed in the casing 44a so as to be displaceable in the radial direction of the casing 44a.

  For example, as shown in FIGS. 3 to 5, the protrusion 44b2 is accommodated in the accommodating portion 44a1 via a spring 44c. Accordingly, the spring 44c biases the protrusion 44b2 and the insertion hole 44b1 in the direction of the protrusion 44b3 by the biasing force. In addition, for example, the protrusion 44b3 is housed in the housing 44a2, and in the state of being urged together with the protrusion 44b2 and the insertion hole 44b1 by the urging force of the spring 44c, as shown in FIGS. Is in contact with the bottom portion of the accommodating portion 44a2. Further, as shown in FIG. 3, the protrusion 44b2 is formed so as to be heavier than the protrusion 44b3.

  In the lock mechanism 40 configured as described above, when the vehicle is stopped and the wheels are not rotating, as shown in FIG. 4, the tip portion of the protrusion 44b3 formed on the shielding plate 44b of the malfunction prevention mechanism 44 is The state is maintained in contact with the bottom portion of the accommodating portion 44a2 formed in the casing 44a. In this state, the axis of the insertion hole 44b1 formed in the shielding plate 44b and the axis of the locking member 41 assembled integrally with the actuator 42 are coaxial. For this reason, when the actuator 42 advances the locking member 41 toward the engaging member 43 along with the extension operation according to a command from the vehicle control device (not shown), the locking member 41 is inserted into the shielding plate 44b. Without contact with the hole 44b1 (that is, without the shielding plate 44b hindering the advancement of the locking member 41), it moves to the engaging member 43 and meshes with each other (for example, spline fitting), and the wheel rotates. Realize the lock state to lock.

  On the other hand, when the vehicle is running and the wheels are rotating, the weight of the protrusion 44b2 formed on the shielding plate 44b of the malfunction prevention mechanism 44 is heavier than the weight of the protrusion 44b3. The magnitude of the centrifugal force generated is greater than the magnitude of the centrifugal force generated at the protrusion 44b3. For this reason, as shown in FIG. 5, the shielding plate 44b faces the projection 44b2 direction, that is, toward the housing portion 44a1 formed in the casing 44a against the urging force of the spring 44c (in other words, the projection 44b3). The tip end portion of the storage portion 44a2 is displaced in a direction away from the bottom portion of the accommodating portion 44a2. As a result, a so-called misalignment occurs in which the axis of the insertion hole 44b1 formed in the shielding plate 44b and the axis of the locking member 41 assembled integrally with the actuator 42 are displaced. When the locking member 41 advances toward the engaging member 43, the locking member 41 comes into contact with the insertion hole 44b1 of the shielding plate 44b (that is, the shielding plate 44b inhibits the advancement of the locking member 41). It becomes impossible to pass through the insertion hole 44b1 of the shielding plate 44b. Thereby, when the wheel is rotating, for example, based on an erroneous operation by the driver, the actuator 42 advances the locking member 41 toward the engaging member 43 by a command from a vehicle control device (not shown). Even if the locking member 41 is in contact with the shielding plate 44b, the forward movement is hindered. For this reason, it is possible to reliably prevent a malfunction in which the locking member 41 moves to the engagement member 43 and meshes with each other while the wheel is rotating while the vehicle is running, and an unlocked state in which the rotation of the wheel is not locked. Realize.

  Here, the rotation input to the planetary gear speed reducer 20 from the output shaft 16 a of the motor body 16 is decelerated by the action of the speed reducer 20. That is, when the rotational force input on the upstream side of the speed reducer 20 is output from the downstream side due to the rotation being reduced by the planetary gear speed reducer 20, it corresponds to a predetermined ratio (specifically, the reduction ratio). Will be increased. As a result, the locking member 41 and the engaging member 43 of the lock mechanism 40 provided in the hollow portion of the output shaft 16a (input shaft) mesh with each other to generate a rotation stopping force, and this rotation stopping force is generated. When input to the planetary gear speed reducer 20 via the output shaft 16a (input shaft), the rotation stopping force input by the speed reduction effect by the speed reducer 20 is increased by a predetermined ratio to the wheels, that is, the tire 11 and the wheel 12. Therefore, a greater static force is generated. In other words, in a situation where the static force necessary to stop the rotation of the wheels of the stopped vehicle is predetermined, the anti-rotation force that the lock mechanism 40 should generate in order to generate this static force is It can be made smaller by generating it upstream of the planetary gear speed reducer 20. Accordingly, since a stationary force that does not rotate the wheels of the stopped vehicle can be generated by generating a small rotation stopping force, for example, the required strength of the locking member 41 and the engaging member 43 of the lock mechanism 40 is obtained. As a result, it is possible to reduce the size of the actuator 42, reduce the weight of each member, and the like.

  As can be understood from the above description, according to the above-described embodiment, the lock mechanism 40 that locks the rotation of the wheel when the vehicle is stopped is used as the output shaft 16a of the motor main body 16 that constitutes a part of the planetary gear reducer 20. It can provide in the hollow part. Thereby, it is not necessary to secure a space for providing the lock mechanism 40 separately, and in particular, the wheel drive device 10 can be reduced in size when the in-wheel motor 13 is employed. Further, since the malfunction prevention mechanism 44 can be provided, when the vehicle travels, the operation of the lock mechanism 40, that is, the malfunction in which the locking member 41 and the engagement member 43 are erroneously engaged with each other is ensured. The locking mechanism 40 can be appropriately operated only when the vehicle is stopped, and the rotation of the wheel can be locked (stationary). In this case, the locking mechanism 44b malfunctions due to a simple structure that is extremely simplified by mechanically causing misalignment according to the balance between the urging force of the spring 44c and the centrifugal force acting when the vehicle travels. Can be reliably prevented. Therefore, the wheel drive device 10 can be downsized also by this.

  In the above embodiment, the malfunction prevention mechanism 44 constituting the lock mechanism 40 is arranged between the locking mechanism 41 and the engagement member 43. When the vehicle is stopped, the locking member 41 is allowed to pass through the insertion hole 44b1 of the shielding plate 44b and mesh with the engaging member 43. When the vehicle is running, the locking member 41 is Engagement with the engaging member 43 is prohibited so that it cannot pass through the insertion hole 44b1 of the shielding plate 44b.

  In this case, as shown in FIG. 6, in the actuator 42 of the locking mechanism 40, when the forward / backward portion (for example, a solenoid pin) has a structure penetrating the actuator 42, for example, it is formed on one end side (base end side). It is also possible to implement the malfunction prevention mechanism 44 from the cutout portion 44e and the solenoid 44d that expands and contracts so that the solenoid pin is hooked on the cutout portion 44e when the vehicle travels. Also in this modified example, when the vehicle travels, the forward / backward movement of the actuator 42 is prohibited, so that the engagement member 41 and the engagement member 43 can be reliably prevented from engaging each other.

  In carrying out the present invention, the present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the object of the present invention.

  For example, in the above embodiment, for example, even if the actuator 42 of the lock mechanism 40 malfunctions during traveling and the locking member 41 is moved forward toward the engagement member 43, the shielding plate 44b of the malfunction prevention mechanism 44 is used. By prohibiting the forward movement of the locking member 41, the locking member 41 and the engaging member 43 are surely prevented from engaging (engaging) with each other during traveling. By the way, in a situation where the malfunction of the actuator 42 accompanying such an extension operation is continued, when the vehicle stops, the locking member 41 contacts the insertion hole 44b1 of the shielding plate 44b by the extension operation of the malfunctioning actuator 42. Without moving (that is, without blocking the forward movement of the locking member 41), there is a possibility that they will move to the engaging member 43 and mesh (engage) with each other. Such engagement (engagement) is an engagement (engagement) when the vehicle is stopped, but it is not intended by the driver, and may cause a sense of discomfort.

  For this reason, as a function of the actuator 42 of the lock mechanism 40, for example, a situation in which an extension operation or a contraction operation is impossible even though a predetermined current is supplied (specifically, it is in contact with the shielding plate 44b). Thus, in the case where it is impossible to displace the locking member 41), it is possible to have a function of interrupting the supply of a predetermined current after a certain time. As a result, when the state in which the locking member 41 and the shielding plate 44b, which are about to move forward due to a malfunction of the actuator 42, continues (contacts) for a certain period of time during traveling, a predetermined amount of electric power is supplied to the actuator 42. Since the supply can be shut off, the locking member 41 can be stopped at that position. As a result, even if the vehicle stops, unintentional engagement (engagement) between the locking member 41 and the engaging member 43 can be prevented. About the other effect, the effect similar to the said embodiment and modification is acquired. Here, as described above, when the supply of electric power to the actuator 42 is interrupted and the locking member 41 is stopped, as a function of the actuator 42 of the lock mechanism 40, the electric power supply is further interrupted. It is possible to have a function of returning the locking member 41 to the original position (that is, the initial position where the actuator 42 is contracted) after a certain period of time has elapsed.

  Moreover, in the said embodiment and modification, it implemented so that the engaging member 43 of the locking mechanism 40 might be integrally fixed with respect to the internal peripheral surface of the output shaft 16a. Thereby, when the vehicle is stopped, the locking member 41 and the engaging member 43 are engaged (engaged), thereby realizing a locked state in which the rotation of the wheel is reliably locked. In this case, for example, it is assumed that the actuator 42 cannot be reduced in the locked state, or the shielding plate 44b (or the solenoid 44d) of the malfunction prevention mechanism 44 becomes inoperable during traveling. The engaging member 43 may be assembled to the inner peripheral surface of the output shaft 16a through a tolerance ring. As a result, even if a state where the locking member 41 and the engaging member 43 are engaged (engaged) due to a malfunction occurs, the engaging member is provided when a large rotational force is generated by providing a tolerance ring. 43 and the output shaft 16a can be allowed to rotate relative to each other. As a result, the wheel can be rotated even in the locked state. About the other effect, the effect similar to the said embodiment and modification is acquired.

  In the embodiment and the modification, a plurality of external teeth are formed on the locking member 41 and a plurality of internal teeth are formed on the engaging member 43. The locking member 41 and the engaging member 43 are The anti-rotation force was generated by meshing with each other. In this case, for example, the locking member 41 and the engaging member 43 may be frictionally engaged with each other to generate a rotation stopping force. Further, regarding the generation of the anti-rotation force, for example, when the vehicle is stopped, the anti-rotation force is generated by fixing the motor body 16 (more specifically, for example, the rotor 16d) by electromagnetic force. Alternatively, it is possible to generate an anti-rotation force by generating an engagement by a magnetic force between the locking member 41 and the engaging member 43. Even in these cases, the same effects as those of the above-described embodiment and the modification can be obtained.

  Moreover, in the said embodiment and modification, it implemented so that the output shaft 16a of the motor main body 16 was formed in the hollow shape, and the lock mechanism 40 was accommodated in the inside of this output shaft 16a. In this case, for example, when the planetary gear speed reducer 20 that is a driving force transmission mechanism is arranged in parallel with respect to the output shaft 16 a of the motor body 16, any of the rotating shafts constituting the speed reducer 20 is selected. Needless to say, this can be implemented by forming a hollow shape and housing the lock mechanism 40 inside the rotating shaft. Even in this case, the same effect as that of the above-described embodiment and the modified example can be obtained by engaging the locking member 41 provided so as not to rotate and the engaging member 43 that rotates integrally with the rotation shaft. .

  Moreover, in the said embodiment and modification, it implemented using the wheel drive device 10 which transmits the rotational drive force of the motor main body 16 to the wheel 12 and the tire 11, ie, a wheel, via the planetary gear speed reducer 20. In this case, by directly controlling the rotational driving force generated by the motor main body 16, a so-called direct drive system wheel drive device that omits the planetary gear speed reducer 20 (that is, the speed reduction mechanism) is used. It is also possible to implement. In this case, the driving force transmission mechanism that transmits the output (driving force) of the motor main body 16 to the wheel including the wheel 12 and the tire 11 corresponds to the output shaft 16a (rotating shaft). For this reason, in this case as well, since the lock mechanism 40 can be provided inside the hollow rotary shaft that constitutes the driving force transmission mechanism that transmits the driving force of the motor main body 16, it is the same as in the above-described embodiment and modification. Can be expected. In this case, since the deceleration effect acting on the rotation stopping force cannot be obtained, it is necessary to increase the rotation stopping force generated by the lock mechanism 40 as compared with the above embodiment and the modification.

  In the above embodiment, the shielding plate 44b constituting the malfunction prevention mechanism 44 is mechanically misaligned according to the balance between the biasing force of the spring 44c and the centrifugal force acting when the vehicle travels. . In this case, it is needless to say that, for example, the shield plate 44b can be electrically displaced using an actuator or the like to cause misalignment. Even in this case, the same effects as those of the embodiment and the modification can be expected.

  Furthermore, in the said embodiment and modification, it implemented by employ | adopting the in-wheel motor 13 as a drive source. However, the drive source may be anything as long as it generates a driving force for driving the wheels of the vehicle. For example, an internal combustion engine or an electric motor that transmits the driving force to the wheels via a drive shaft or the like. Needless to say, it can be implemented by adopting. Even in this case, since the driving force is transmitted to the tire 11 and the wheel 12 via the planetary gear speed reducer 20 as a speed reducer constituting the driving force transmission mechanism, the same effects as those of the above-described embodiment and the modified example are obtained. Is obtained.

DESCRIPTION OF SYMBOLS 10 ... Braking / driving device, 11 ... Tire, 12 ... Wheel, 13 ... In-wheel motor, 14 ... Knuckle, 15 ... Brake disk rotor, 16 ... Motor body, 17 ... Motor case, 20 ... Planetary gear speed reducer, 21, 22 ... Planetary gear mechanism, 21a, 22a ... 1st sun gear, 2nd sun gear, 21b, 22b ... 1st planetary gear, 2nd planetary gear, 21c, 22c ... 1st ring gear, 2nd ring gear, 21d, 22d ... 1st 1 carrier pin, 2nd carrier pin, 21e, 22e ... 1st planetary carrier, 2nd planetary carrier, 21f ... Shaft, 23 ... Inner ring side member, 23a ... Brim part, 30 ... Axle bearing, 31 ... Inner race, 32 ... Outer ring side member 33 ... Outer race 34 ... Bearing ball 40 ... Lock mechanism 41 ... Locking member 41 Actuator 43 ... engaging member, 44 ... malfunction preventing mechanism, 44a ... casing, 44b ... shielding plate, 44c ... Spring

Claims (9)

In a wheel drive device comprising: a drive source that generates a drive force for driving a wheel of a vehicle; and a drive force transmission mechanism that transmits an output from the drive source to the wheel.
A wheel drive device characterized in that at least one rotating shaft constituting the driving force transmission mechanism is formed in a hollow shape, and a lock mechanism for locking the rotation of the wheel is provided in the hollow portion. In the wheel drive device according to claim 1,
The locking mechanism;
Locking means fixed non-rotatably to the vehicle body side of the vehicle;
Engaging means for rotating integrally with the rotating body and engaging with the locking means;
A wheel drive device comprising: an engaging / retracting means for advancing and retracting the locking means relative to the engaging means. In the wheel drive device according to claim 1 or 2,
A wheel drive device comprising a malfunction prevention mechanism for preventing the lock mechanism from operating when the wheel is rotating. In the wheel drive device according to claim 3,
The malfunction prevention mechanism is
A wheel drive device that operates with the rotation of the wheel to prevent the lock mechanism from operating. In the wheel drive device according to claim 4,
The malfunction prevention mechanism is
A wheel driving device that operates by a centrifugal force generated with the rotation of the wheel to prevent the lock mechanism from operating. In the wheel drive device according to any one of claims 1 to 5,
The driving force transmission mechanism is
A wheel drive device comprising a speed reducer that decelerates an output from the drive source and transmits the output to the wheel. In the wheel drive device according to claim 6,
The speed reducer,
A sun gear that receives an output from the drive source, a ring gear fixed to the vehicle body side, a plurality of planetary gears that revolve around the sun gear by meshing between the sun gear and the ring gear, and a vehicle A wheel driving device comprising: a planetary carrier disposed outside and fixed to a carrier pin of the plurality of planetary gears. In the wheel drive device according to claim 7,
The locking mechanism;
A wheel drive device characterized by being provided in a hollow portion of an input shaft for inputting an output from the drive source to the speed reducer. In the wheel drive device according to any one of claims 1 to 8,
The drive source is
A wheel drive device comprising an in-wheel motor provided in a wheel forming the wheel and generating a driving force.

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