JP4312078B2 - Electric wheel - Google Patents

Description

  The present invention relates to an electric wheel that improves the riding comfort of a vehicle.

Conventionally, as an in-wheel motor drive unit that uses a motor as a damper mass, a hollow motor supported by a motor suspension is known (Non-Patent Document 1). The hollow motor is connected to the wheel of the wheel and rotates the wheel. The hollow motor is supported by the motor suspension so as to vibrate in the vertical direction of the vehicle, and is separated from the unsprung weight. The wheel is supported by the vehicle by the suspension arm. In this in-wheel motor drive system, when the wheel vibrates, the hollow motor receives the vibration of the wheel via the wheel and vibrates in the vertical direction of the vehicle. The vibration of the hollow motor cancels out the unsprung vibration. In this case, a flexible coupling is used so that the power generated by the motor is smoothly transmitted to the wheel even if the motor and the rotational axis of the wheel are displaced.
JP 2003-530263 A Go Nagaya and two others, “Development of Dynamic Damper Type In-Wheel Motor (20025544)”, Preprint of Scientific Lecture No. 83-02, Society of Automotive Engineers of Japan, November 26, 2002, p9-12

  However, the conventional dynamic damper type in-wheel motor drive system does not include a speed reducer that increases the output torque of the motor, and the motor is dependent on the torque required for vehicle travel, so the size of the motor increases. There was a problem.

  For this reason, there existed a problem that the whole size of an electrically-driven wheel will become large.

  Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide a small and high-powered electric wheel while improving the riding comfort of the vehicle.

  An electric wheel according to the present invention is provided between a motor provided corresponding to a wheel of the wheel, a rotation support member that rotatably supports the wheel, and the motor and the rotation support member. An elastic member arranged so as to attenuate vibrations of the members, a constant velocity joint attached to the output shaft of the motor, and a speed reducer that changes the rotation of the motor transmitted by the constant velocity joint.

  Preferably, the motor, the constant velocity joint, and the speed reducer are arranged in the order of the motor, the constant velocity joint, and the speed reducer from the vehicle body side to the wheel side.

  Preferably, the speed reducer includes a planetary gear.

  More preferably, the planetary gear is a stepped pinion gear in which a sun gear to which rotation is transmitted by a constant velocity joint, a first gear meshing with the sun gear, and a second gear having a diameter different from that of the first gear are coupled. And a ring gear meshing with the second gear.

  Preferably, the rotation support member includes a knuckle that rotatably supports the wheel, and a case that houses a speed reducer coupled integrally with the knuckle.

  Preferably, there is further provided a regulating member that regulates the movement locus of the motor so that the center of gravity of the motor reciprocates on a straight line passing through the position of the center of gravity of the motor when the vibration of the wheel is stationary.

  According to the present invention, since the motor, the constant velocity joint, the speed reducer, and the wheel are arranged in this order from the vehicle body side in the power transmission path, it is easy to increase the speed reduction ratio of the speed reducer. For this reason, even if a motor with the same torque is used, it is possible to increase the rotational force of the wheel by rotating it at a high speed and decelerating with a reducer with a large reduction ratio. Is possible. Also, if the reduction gear ratio is large, the motor torque can be small even if the wheel torque is the same. Therefore, the diameter of the motor can be reduced, and interference with the suspension arm during rotation of the steering wheel is less likely to occur.

  In addition, an in-wheel motor is used as the load member, and while effectively utilizing the weight of the required device, the movement trajectory of the load member is regulated so that the vibration of the wheel is preferably transmitted as the vibration of the load member. Riding comfort can be improved.

  Further, since the reduction ratio is increased, the motor shaft can be made thinner, and the constant velocity joint can be made smaller.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a schematic cross-sectional view of an electric wheel according to an embodiment of the present invention.

  First, the overall configuration of FIG. 1 will be described. The electric wheel 100 includes a wheel disc 10, a wheel hub 20, a brake rotor 40, a brake caliper 50, an in-wheel motor IWM, a knuckle 180, dampers 140 and 150, and a tire 250.

  The in-wheel motor IWM includes a motor case 60, a motor 70, a shaft 110, a constant velocity joint 30, a reduction gear 80, and an oil pump 90.

  The wheel support device 200 that supports the electric wheel 100 includes an upper arm 210, a lower arm 220, and ball joints 160 and 170.

  The power of the motor 70 is output from the shaft 110. The shaft 110 is connected to the speed reducer 80 via the constant velocity joint 30. Accordingly, the rotation of the shaft 110 is decelerated by the speed reducer 80 and transmitted to the wheel hub 20 to rotate the wheel disc 10.

  Next, the configuration of each individual element will be described.

  The wheel disc 10 has a substantially cup shape, and includes a disc portion 10A and a rim portion 10B. The wheel disc 10 houses the wheel hub 20, the brake rotor 40, the brake caliper 50, and the in-wheel motor IWM. The tire 250 is fixed to the outer edge of the rim portion 10B of the wheel disc 10.

  The wheel disc 10 is connected to the wheel hub 20 by fastening the disc portion 10A to the bolts 1 and 2 attached to the wheel hub 20 by the wheel nuts 3 and 4. A hub spindle 21 is inserted into the wheel hub 20, and the wheel hub 20 and the hub spindle 21 are fastened by a hub nut 22. The wheel hub 20 is rotatably supported by hub bearings 11 and 12 fitted in the hub bearing case 23.

  The hub bearing case 23 is fixed to the knuckle 180 by screws 24 and 25. The knuckle 180 is integrated with the case of the speed reducer 80.

  The brake rotor 40 is arranged such that the inner peripheral end is fixed to the outer peripheral end of the wheel hub 20 by bolts 1 and 2 and wheel nuts 3 and 4, and the outer peripheral end passes through the brake caliper 50. The brake caliper 50 is fixed to the knuckle 180 so as to be movable in the moving direction of the brake piston. The brake caliper 50 includes a brake piston 51 and brake pads 52 and 53. The brake pads 52 and 53 sandwich the outer peripheral end of the brake rotor 40 therebetween.

  When the brake oil is supplied, the brake piston 51 pushes the brake pad 52. When the brake pad 52 is pressed against the outer periphery of the brake rotor 40 by the brake piston 51, the entire brake caliper 50 is moved toward the vehicle body by the reaction force. For this reason, the brake pad 53 moves toward the vehicle body side. As a result, the brake pads 52 and 53 sandwich the outer peripheral end of the brake rotor 40, and the electric wheel 100 is braked.

  The knuckle 180 is disposed on the vehicle body side of the wheel hub 20. The knuckle 180 is integrated with a case that houses the speed reducer 80 and the constant velocity joint 30.

  The constant velocity joint 30 includes a guide 31 and a needle bearing 32. The guide 31 abuts against the wall surface of the space inside the other end of the sun gear shaft on which the sun gear 82 is formed at one end. Since the needle bearing 32 can move in the groove provided at the other end of the sun gear shaft in the direction along the rotation axis of the shaft 110, the shaft 110 can slide in the direction along the rotation axis.

  Here, since the shaft 110 is movable in the axial direction, the force in the direction along the rotation axis with respect to the constant velocity joint 30 can be released, so that the constant velocity joint 30 can be reduced in size.

  The reduction gear 80 is a planetary gear (planetary gear) using stepped pinion gears (stepped small gears) 83a and 83b. By using the stepped pinion gears 83a and 83b, a large reduction ratio can be realized while keeping the diameter of the ring gear 85 small.

  Reducer 80 includes a sun gear shaft, sun gear 82, pinion gears 83a and 83b, planetary carriers 84a and 84b, ring gear 85, and pins 86a and 86b. A sun gear 82 is formed at one end of the sun gear shaft. The sun gear shaft is connected to the shaft 110 of the motor 70 through the constant velocity joint 30. The sun gear shaft is rotatably supported by the bearing 17.

  Pinion gears 83a and 83b mesh with sun gear 82 and are rotatably supported by pins 86a and 86b, respectively. The planetary carriers 84a and 84b support the pins 86a and 86b from both sides. The planetary carrier 84 a is rotatably supported by the bearing 16. In addition, the planetary carrier 84b has a hub spindle 21 on the wheel side, and is rotatably supported together with the wheel hub 20 by hub bearings 11 and 12.

  The ring gear 85 is fixed to a knuckle 180 that is a case of the speed reducer 80. Ring gear 85 meshes with pinion gears 83a and 83b. Each of the pinion gears 83a and 83b is a stepped gear, and the diameter of the portion engaged with the sun gear 82 is large, and the diameter of the portion engaged with the ring gear 85 is smaller than that portion. By using the stepped pinion gear, the reduction ratio can be increased even if the diameter of the ring gear is small. In order to fit the reduction gear in the wheel, it is necessary to reduce the diameter of the reduction gear 80. In this respect, a planetary gear using a stepped pinion gear is advantageous.

  In order to generate a large torque with a motor, it is generally necessary to increase the diameter of the rotor. This is because a larger torque can be generated as the point where the repulsive force or attractive force of the coil and the magnet acts is farther from the center of rotation. For this reason, it has been difficult to employ an in-wheel motor that has a limited motor mounting space for large vehicles that require power. However, if the reduction ratio between the motor output shaft and the wheel can be increased, a large torque can be transmitted to the wheel by rotating at high speed even with a small torque motor. A motor can be used.

  Further, if the same torque is to be generated in the wheel, the torque generated by the motor may be smaller if a reduction gear having a large reduction ratio is employed. Therefore, the diameter of the motor can be reduced. If the diameter of the motor can be reduced, the knuckle upper portion 180a and the knuckle lower portion 180b can be brought closer to the shaft of the motor. This is effective for preventing the interference between the upper arm 210 and the knuckle upper portion 180a and the interference between the lower arm 220 and the knuckle lower portion 180b when the knuckle 180 rotates around the king pin 26 when the handle is cut. .

  Motor 70 includes a stator core 71, a stator coil 72, and a rotor 73. The stator core 71 is fixed to the motor case 60. The oil pump 90 is provided outside the motor case 60 and on one end side of the shaft 110. The stator coil 72 is wound around the stator core 71. When motor 70 is a three-phase motor, stator coil 72 includes a U-phase coil, a V-phase coil, and a W-phase coil.

The rotor 73 is disposed on the inner peripheral side of the stator core 71 and the stator coil 72.
The shaft 110 is rotatably supported by bearings 14 and 15.

  The oil passage 121 has one end connected to the oil pump 90 and the other end inserted into the oil reservoir 130. The oil pump 90 pumps up the oil accumulated in the oil reservoir 130 via the oil passage 121 and supplies the pumped oil to the end of the shaft 110.

  The dampers 140 and 150 have a configuration in which oil is sealed in rubber, and are attached to the motor case 60. More specifically, the dampers 140 and 150 are attached to the motor case 60 from the vertical direction DR1 of the vehicle body. The dampers 140 and 150 are disposed on the central axes of the springs 260 and 270, respectively.

  Although arrangement | positioning of this damper is not limited, It is preferable to arrange | position on the axis | shaft parallel to the up-down direction DR1 of the vehicle body which passes the gravity center of the motor 70 which is a load member. By doing so, the vibration transmission and buffering effect of the two dampers 140 and 150 can be preferably extracted.

  The knuckle upper portion 180 a is connected to the ball joint 160. The knuckle lower part 180 b is connected to the ball joint 170.

  The upper arm 210 and the lower arm 220 are arranged so as to sandwich the in-wheel motor IWM in the vertical direction DR1 of the vehicle body. The upper arm 210 has one end connected to the ball joint 160 and the other end fixed to the vehicle body so as to be rotatable in the vertical direction DR1 of the vehicle body. The lower arm 220 has one end connected to the ball joint 170 and the other end fixed to the vehicle body so as to be rotatable in the vertical direction DR1 of the vehicle body. The lower arm 220 is connected to the vehicle body via a shock absorber (not shown). As a result, the electric wheel 100 is suspended from the vehicle body.

  Thus, the upper arm 210 and the lower arm 220 are connected to the knuckles 180a and 180b by the ball joints 160 and 170, respectively. The damper 140 is provided between the knuckle 180 a and the upper part of the motor case 60, and the damper 150 is provided between the knuckle 180 b and the lower part of the motor case 60.

  In order to limit the movement of the motor 70 to a linear movement in the vertical direction, a torque rod 300 indicated by a broken line in FIG. 1 is provided. In FIG. 1, the torque rod 300 is arranged on a straight line passing through the center of gravity of the motor 70 and parallel to the vertical direction DR1.

  Actually, as will be described later with reference to FIG. 2, two torque rods 300 are arranged on both sides of the motor case 60. Since the movement is limited by the torque rod, when the wheel vibrates, the center of gravity of the motor 70 moves up and down along a straight line passing through the center of gravity of the motor 70. By using the torque rod 300 as the restricting member, stress due to vibration of the load member applied to the constant velocity joint 30 is reduced, so that the constant velocity joint can be reduced in size.

  Since the upper arm 210 and the lower arm 220 are fixed to the vehicle body so as to be rotatable in the vertical direction DR1 of the vehicle body, and the lower arm 220 is connected to the vehicle body via a shock absorber (not shown), the upper arm 210, the lower arm 220 and the shock absorber are Functions as a suspension.

  The wheel support device 200 supports the knuckle 180 by suspension arms (upper arm 210 and lower arm 220) and ball joints 160, 170, and supports the motor case 60 by dampers 140, 150 and torque rods attached to the knuckle. The electric wheel 100 is supported on the vehicle body.

  That is, the wheel support device 200 rotatably supports the wheel disc 10 and the wheel hub 20 by the upper arm 210, the lower arm 220, and the knuckle 180. The motor 70 is supported by the upper arm 210, the lower arm 220, the knuckle 180, the dampers 140 and 150, and the torque rod 300 so as to vibrate in the vertical direction DR1 of the vehicle body.

  When the electric wheel 100 is vibrated in the vertical direction DR1 of the vehicle body according to the road surface condition or the like while the vehicle is running, the dampers 140 and 150 are deformed in the vertical direction DR1 of the vehicle body by the motor 70 serving as a damper mass. The vibration in the vertical direction DR1 of the motor 70 that is out of phase with the vibration received by the wheel 100 is generated.

  That is, the dampers 140 and 150 convert the vibration of the electric wheel 100 into the vibration of the motor 70. The dampers 140 and 150 cause the motor 70 to cancel the vibration received by the electric wheel 100. If it does so, it will become difficult to transmit the vibration of the motor-driven wheel 100 to the vehicle body via the upper arm 210 and the lower arm 220.

  Thereby, the unsprung input from the tire 250 is relieved. That is, vibrations that cannot be absorbed by the shock absorber are absorbed. As a result, the ride comfort of the vehicle is improved.

  When an alternating current is supplied to the stator coil 72 by a switching circuit (not shown) mounted on the vehicle body, the rotor 73 rotates and the motor 70 outputs a predetermined torque. The output torque of the motor 70 is transmitted from the shaft 110 to the speed reducer 80 via the constant velocity joint 30.

  The reducer 80 changes the output torque received by the sun gear 82 via the sun gear shaft by the sun gear 82 and the pinion gears 83a and 83b, that is, shifts (decelerates) the output torque and outputs it to the planetary carrier 84b. The planetary carrier 84b transmits the output torque of the speed reducer 80 to the hub spindle 21, and the hub spindle 21 rotates the wheel hub 20 and the wheel disc 10 at a predetermined rotational speed. Thereby, the electric wheel 100 rotates at a predetermined number of rotations.

  2 is a view of the motor-driven wheel shown in FIG. 1 as viewed from the vehicle body side as indicated by an arrow A in FIG. Note that the upper arm 210, the lower arm 220, the tire 250, the wheel disc 10, the brake caliper 50, and the brake rotor 40 are not shown in FIG.

  Referring to FIG. 2, a damper 140 is disposed between the knuckle 180 a and the upper part of the motor case 60. Similarly, a damper 150 is disposed between the knuckle 180 b and the lower part of the motor case 60.

  Torque rods 300a and 300b are inserted on both sides of the in-wheel motor IWM from the knuckle 180a to the knuckle 180b. A female screw is cut in the knuckle 180b. The front ends of the torque rods 300a and 300b are cut with male screws, and the torque rods 300a and 300b pass through the knuckle 180a and are screwed into the knuckle 180b.

  Arms 310a and 310b are attached to the torque rods 300a and 300b, respectively, so as to be movable in the direction along the torque rod. Bearings 312a and 312b are attached to the arms 310a and 310b, respectively, and rotatably support the pins 314a and 314b. The pins 314a and 314b are supported with the motor case 60 interposed therebetween.

  Therefore, the motor case 60 can rotate around the axis connecting the pins 314a and 314b.

  FIG. 3 is a conceptual diagram for explaining the vertical vibration of the motor and the arrangement of the power transmission elements.

  Referring to FIG. 3, as a load member, the motor moves up and down according to the vibration of the wheel to cancel the vibration and make it difficult to transmit the road surface vibration to the vehicle body. With the structure shown in FIGS. 1 and 2, the gravity center position of the load member moves up and down as shown by positions 400, 401, and 402 along an axis 405 that is a straight line passing through the gravity center. Since the constant velocity joint 30 is provided with a needle bearing 32, such a movement is possible. Further, since the force generated by the vibration is received by the torque rod and the upper and lower dampers, the force applied to the constant velocity joint is reduced. Therefore, the constant velocity joint 30 can be reduced in size.

  Although it is conceivable that the motor and the speed reducer are integrated as a load member and the output of the speed reducer is input to the constant velocity joint, the configuration shown in FIG. 3 can reduce the weight of the load member. In this respect, the constant velocity joint 30 can be reduced in size.

  In addition, since the motor as the load member moves up and down on the straight line with respect to the vertical movement of the wheel, the effect of canceling out the vibration can be further increased.

  Further, when the motor (position 400), the constant velocity joint 30, the speed reducer 80, and the wheel connected to the hub spindle 21 are arranged in this order, it is easy to secure the length of the speed reducer in the axial direction, and a planetary gear using a stepped pinion. Easy to adopt. Therefore, it is easy to increase the reduction ratio of the reduction gear. For this reason, even if a motor with the same torque is used, it is possible to increase the rotational force of the wheel by rotating it at a high speed and decelerating with a reducer with a large reduction ratio. Is possible.

  In addition, if the reduction ratio is large, the motor torque can be small even if the rotational force of the wheel is the same. Therefore, the diameter D of the motor shown in FIG. 3 can be reduced, and interference with the suspension arm during the rotation of the handle is less likely to occur.

  In the present invention, a spring with a bush or a damper in which a viscous material is enclosed may be used instead of the dampers 140 and 150 in FIG. In other words, in the present invention, the in-wheel motor IWM only needs to be supported by an elastic body or a damper so as to vibrate.

  In the present embodiment, the wheel disc 10 and the wheel hub 20 constitute a “wheel”.

  The dampers 140 and 150 constitute an “elastic member”. The pair of elastic members are connected to both the upper arm 210 and the lower arm 220.

  Further, the knuckle 180 constitutes a “rotation support member” that rotatably supports the wheel (wheel disc 10 and wheel hub 20) of the electric wheel 100.

  According to the present invention, when the electric wheel 100 is vibrated according to the road surface condition or the like while the vehicle is running, the “elastic member” causes the motor 70 that is a load member to move up and down the vehicle body by the vibration received by the electric wheel 100. The vibration is caused by shifting the phase in the direction DR1, and as a result, a large vibration is not transmitted (cancelled) to the vehicle body on the spring. Thereby, the riding comfort of the vehicle carrying the wheel driven by the in-wheel motor IWM is improved.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

1 is a schematic cross-sectional view of an electric wheel according to an embodiment of the present invention. It is the figure which looked at the electrically-driven wheel shown in FIG. 1 from the vehicle body side, as shown by the arrow A of FIG. It is a conceptual diagram for demonstrating the vibration of a motor up-down direction, and arrangement | positioning of a power transmission element.

Explanation of symbols

  1, 2 bolt, 3, 4 wheel nut, 10 wheel disc, 10A disc portion, 10B rim portion, 11, 12 hub bearing, 14-17 bearing, 20 wheel hub, 21 hub spindle, 22 hub nut, 23 hub bearing case, 26 kingpin, 30 constant velocity joint, 31 guide, 32 needle bearing, 40 brake rotor, 50 brake caliper, 51 brake piston, 52, 53 brake pad, 60 motor case, 70 motor, 71 stator core, 72 stator coil, 73 rotor, 80 reducer, 82 sun gear, 83a, 83b stepped pinion gear, 84a, 84b planetary carrier, 85 ring gear, 86a, 86b Pin, 90 oil pump, 100 motorized wheel, 110 shaft, 121 oil passage, 130 oil reservoir, 140,150 damper, 160,170 ball joint, 180 knuckle, 180a knuckle upper part, 180b knuckle lower part, 200 wheel support device, 210 upper Arm, 220 Lower arm, 250 Tire, 260,270 Spring, 300 Torque rod, 300a, 300b Torque rod, 310a, 310b Arm, 312a, 312b Bearing, 314a, 314b Pin, IWM in-wheel motor.

Claims (5)

A motor provided corresponding to the wheel of the wheel;
A rotation support member for rotatably supporting the wheel;
Elasticity mounted between the motor and the rotation support member, disposed so as to attenuate the vibration of the wheel and the vibration of the motor , and supporting the motor so as to be swingable with respect to the rotation support member Members,
A constant velocity joint attached to the output shaft of the motor;
A motor-driven wheel comprising: a reduction gear mounted to be integrated with the rotation support member and configured to change a speed of rotation of the motor transmitted by the constant velocity joint.   The motor wheel according to claim 1, wherein the motor, the constant velocity joint, and the speed reducer are arranged in the order of the motor, the constant velocity joint, and the speed reducer from a vehicle body side toward a wheel side. Further comprising a regulating member for regulating the movement trajectory of the motor so as a straight line passing through the center of gravity of the motor in a state in which the vibration of the wheel is stationary center of gravity of the motor reciprocates claim 1 or 2 The electric wheel described in 1. The regulating member is
A pair of torque rods provided on both sides of the motor in parallel with the straight line;
A pair of arms movably attached in a direction along each of the pair of torque rods,
4. The electric wheel according to claim 3, wherein the case is attached to the arm so that the motor is rotatable about an axis orthogonal to both an output shaft of the motor and a straight line passing through the center of gravity of the motor. A pair of pins that support the motor on both sides;
The motor-driven wheel according to claim 4, further comprising a pair of bearings respectively attached to the pair of arms that rotatably support the pair of pins.

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