JP4474176B2 - Wheel support device - Google Patents

Description

  The present invention relates to a wheel support device that improves the riding comfort of a vehicle.

  In the conventional in-wheel motor drive system, as disclosed in Japanese Patent Application Laid-Open No. 2003-530263 (Patent Document 1), the motor structure is pivoted around a center of gravity or a pivot extending adjacent thereto. Therefore, the balance reduces the unbounced weight of the wheels and knuckles. The rotation of the motor structure is transmitted to the wheels via a constant velocity joint.

Further, as a conventional in-wheel motor drive system, a hollow motor supported by a motor suspension is known (Non-Patent Document 1). The rotor of the hollow motor is connected to the wheel of the wheel and rotates the wheel. The stator of the hollow motor is supported by a 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 through 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, in the conventional in-wheel motor drive system, it is necessary to design the above-mentioned constant velocity joint and flexible coupling so as to be able to withstand the load accompanying the relative movement of the motor in the vertical direction, and a certain level of strength is required. It was not possible to reduce the size sufficiently.

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

  Accordingly, the present invention has been made to solve such a problem, and an object thereof is to provide a wheel support device that further improves the riding comfort of the vehicle and is downsized.

  According to this invention, the wheel support device is attached to a load member provided in the wheel of the wheel, and has an elastic member arranged so as to attenuate the vibration of the wheel and the vibration of the load member, and one end thereof A suspension arm coupled to the elastic member, the other end of which is fixed to the vehicle body so as to be rotatable in the vertical direction of the vehicle body, a rotation support member coupled to the suspension arm and the elastic member, and rotatably supporting the wheel of the wheel; And a regulating member that regulates the movement locus of the load member so that the center of gravity of the load member reciprocates on a straight line passing through the position of the center of gravity of the load member in a state where the vibration of the wheel is stationary.

  Preferably, the load member is provided on the output shaft so that the motor, the output shaft for outputting the power generated by the motor, and the displacement along the output shaft of the motor in accordance with the reciprocating motion of the center of gravity of the load member are possible. A constant velocity joint that is attached and transmits the rotation of the output shaft to the wheel, and a case that is attached to the suspension arm via an elastic member and accommodates the motor.

  More preferably, the load member further includes a transmission that changes the number of rotations of the motor at a predetermined ratio and transmits it to the output shaft.

  More preferably, the restricting member includes a pair of torque rods provided on both sides of the load member in parallel with the straight line, and a pair of arms movably attached in a direction along the pair of torque rods, and the case includes: The load member is attached to the arm so as to be rotatable about an axis orthogonal to both the output shaft of the motor and a straight line passing through the center of gravity of the load member.

  Preferably, the suspension arm includes a lower arm and an upper arm, and the elastic member is between a first elastic member provided between an end of the lower arm and the case, and an end of the upper arm and the case. And a second elastic member provided.

  More preferably, the first and second elastic members are provided on a straight line passing through the center of gravity.

  According to this invention, the movement trajectory of the load member is restricted, so that the vibration of the wheel is preferably transmitted as the vibration of the load member, and the riding comfort of the vehicle can be improved.

  Further, by using an in-wheel motor or a transmission as the load member, it is possible to improve the riding comfort of a vehicle driven by the in-wheel motor while effectively utilizing the weight of the necessary device.

  Further, by using the torque rod as the restricting member, stress due to vibration of the load member applied to the constant velocity joint is reduced, so that the constant velocity joint can be reduced in size.

  Furthermore, since the elastic members are attached to both the lower arm and the upper arm and the two elastic members are provided on a straight line passing through the center of gravity of the load member, it is possible to preferably draw out the vibration transmission and the buffering effect of the elastic member.

  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 a wheel support device according to Embodiment 1 of the present invention and an electric wheel supported thereby.

  Referring to FIG. 1, electric wheel 100 includes a wheel disc 10, a wheel hub 20, a constant velocity joint 30, a brake rotor 40, a brake caliper 50, an in-wheel motor IWM, and a tire 250.

  In-wheel motor IWM includes a case 60, a motor 70, a planetary gear 80, an oil pump 90, a shaft 110, and an oil passage 120.

  Wheel support device 200 includes dampers 140 and 150, ball joints 160 and 170, knuckle 180, upper arm 210, lower arm 220, and shock absorber 230.

  The wheel disc 10 has a substantially cup shape, and includes a disc portion 10A and a rim portion 10B. The wheel disc 10 may house the wheel hub 20, the brake rotor 40, the brake caliper 50, and the in-wheel motor IWM. The wheel disc 10 is coupled to the wheel hub 20 by fastening the disc portion 10A to the wheel hub 20 with screws 1 and 2. The wheel hub 20 incorporates a constant velocity joint 30 and is connected to the shaft 110 via the built-in constant velocity joint 30. The wheel hub 20 is rotatably supported by the knuckle 180 by the hub bearings 11 and 12.

  The constant velocity joint 30 includes a guide 31 and a needle bearing 32. The guide 31 contacts the wheel hub 20. Since the needle bearing 32 can move in the groove of the wheel hub 20 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 brake rotor 40 is arranged so that the inner peripheral end is fixed to the outer peripheral end of the wheel hub 20 by screws 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. 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.

  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 case 60 is disposed on the vehicle body side of the wheel hub 20. Case 60 accommodates motor 70, planetary gear 80, oil pump 90, shaft 110, and oil passage 120.

  Motor 70 includes a stator core 71, a stator coil 72, and a rotor 73. The stator core 71 is fixed to the case 60. 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.

  Planetary gear 80 includes a sun gear shaft 81, a sun gear 82, a pinion gear 83, a planetary carrier 84, a ring gear 85, and a pin 86. Sun gear shaft 81 is connected to rotor 73 of motor 70. The sun gear shaft 81 is rotatably supported by the bearings 14 and 15. Sun gear 82 is connected to sun gear shaft 81.

  The pinion gear 83 meshes with the sun gear 82 and is rotatably supported by a bearing disposed on the outer periphery of the pin 86. Planetary carrier 84 is connected to pinion gear 83 and is splined to shaft 110. The planetary carrier 84 is rotatably supported by the bearings 16 and 17. Ring gear 85 is fixed to case 60. The pin 86 is supported by the pinion gear 83 via a bearing disposed around the pin 86.

  The oil pump 90 is provided at one end of the shaft 110. The shaft 110 is rotatably supported by bearings 13 and 17. The shaft 110 incorporates an oil passage 111 and an oil hole 112.

  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 stored in the oil reservoir 130 through the oil passage 121 and supplies the pumped oil to the oil passage 111.

  The tire 250 is fixed to the outer edge of the rim portion 10B of the wheel disc 10.

  The dampers 140 and 150 have a configuration in which oil is sealed in rubber, and are attached to the case 60 of the in-wheel motor IWM. More specifically, the damper 140 is provided between the knuckle upper portion 180 a and the case 60, and the damper 150 is provided between the knuckle lower portion 180 b and the case 60. 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 in-wheel motor IWM 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 180 (180a) has one end connected to the ball joint 160 and the other end connected to the wheel hub 20 via the hub bearings 11 and 12. One end of the knuckle 180 (180b) 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. Further, the lower arm 220 is connected to the vehicle body via a shock absorber 230. 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 case 60, and the damper 150 is provided between the knuckle 180 b and the lower part of the case 60.

  And in order to restrict | limit the motion of the in-wheel motor IWM to a linear motion to an up-down direction, the torque rod 300 shown with 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 in-wheel motor IWM and parallel to the vertical direction DR1. Actually, as will be described later with reference to FIG. 2, two torque rods are arranged on both sides of the in-wheel motor IWM. Since the movement is limited by the torque rod, the in-wheel motor IWM as a load member moves up and down along a straight line passing through the center of gravity of the in-wheel motor IWM when the wheel vibrates. 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 the shock absorber 230, the upper arm 210, the lower arm 220, and the shock absorber 230 Functions as a suspension. The upper arm 210 and the lower arm 220 constitute a “suspension arm”.

  The wheel support device 200 fixes the dampers 140 and 150 to the case 60 of the in-wheel motor IWM, and connects the suspension arms (the upper arm 210 and the lower arm 220) to the dampers 140 and 150 and the knuckle 180 by the ball joints 160 and 170. Thus, 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, and the in-wheel by the upper arm 210, the lower arm 220, the dampers 140, 150, and the torque rod 300. The motor IWM is supported so as to be able to vibrate in the vertical direction DR1 of the vehicle body.

  When the electric wheel 100 receives vibration 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 moved in the vertical direction of the vehicle body by the in-wheel motor IWM (motor 70) serving as a damper mass. The vibration is transformed into DR1 to generate vibration in the vertical direction DR1 of the in-wheel motor IWM (motor 70) out of phase with the vibration received by the electric wheel 100. That is, the dampers 140 and 150 convert the vibration of the electric wheel 100 into the vibration of the motor 70. And the dampers 140 and 150 make the in-wheel motor IWM 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, vibration that cannot be absorbed by the shock absorber 230 is 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 to the planetary gear 80 through the sun gear shaft 81. The planetary gear 80 changes the output torque received from the sun gear shaft 81 by the sun gear 82 and the pinion gear 83, that is, shifts (decelerates) and outputs it to the planetary carrier 84. The planetary carrier 84 transmits the output torque of the planetary gear 80 to the shaft 110, and the shaft 110 rotates the wheel hub 20 and the wheel disc 10 at a predetermined rotation speed via the constant velocity joint 30. Thereby, the electric wheel 100 rotates at a predetermined number of rotations.

  On the other hand, the oil pump 90 pumps oil from the oil reservoir 130 through the oil passage 120 and supplies the pumped oil to the oil passage 111 provided inside the shaft 110.

  Then, the oil supplied to the oil passage 111 is discharged from the oil hole 112 by the centrifugal force generated by the rotation of the shaft 110 while moving in the oil passage 111. The oil passage 121 supplies the oil discharged from the shaft 110 to the planetary gear 80 and lubricates the planetary gear 80. The oil discharged from the shaft 110 cools the stator coil 72 and lubricates the bearings 14-17.

  FIG. 2 is a view of the wheel support device shown in FIG. 1 as viewed from the vehicle body side as indicated by an arrow A in FIG. Note that the shock absorber 230, 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 portion of the motor case 60. Similarly, a damper 150 is disposed between the knuckle 180 b and the lower portion 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 can be rotated around the axis connecting the pins 314a and 314b.

  FIG. 3 is a conceptual diagram for explaining the vertical vibration of the in-wheel motor.

  Referring to FIG. 3, the in-wheel motor functions as a load member that 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 the needle bearing 32, the shaft 110 can move in this manner. 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.

  Further, since 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.

  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 in-wheel motor IWM constitutes a “load member”. If the wheel is not an electric wheel, a mere weight can be used as the “load member” instead of the motor.

  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 receives vibration according to the road surface condition or the like while the vehicle is running, the “elastic member” causes the “load member” to be moved in the vertical direction DR1 of the vehicle body by the vibration received by the electric wheel 100. The phase is shifted in phase, and as a result, large vibration is not transmitted (cancelled) to the 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.

It is a schematic sectional drawing of the wheel support apparatus by Embodiment 1 of this invention, and the electric wheel supported by it. It is the figure which looked at the wheel support device shown in FIG. 1 from the vehicle body side as shown by the arrow A in FIG. It is a conceptual diagram for demonstrating the vibration of an up-down direction of an in-wheel motor.

Explanation of symbols

  1 to 4 screws, 10A disk part, 10 wheel disk, 10B rim part, 11, 12 hub bearing, 13-17 bearing, 20 wheel hub, 30 constant velocity joint, 31 guide, 32 needle bearing, 40 brake rotor, 50 brake Caliper, 51 brake piston, 52, 53 brake pad, 60 case, 70 motor, 71 stator core, 72 stator coil, 73 rotor, 80 planetary gear, 81 sun gear shaft, 82 sun gear, 83 pinion gear, 84 planetary carrier, 85 ring gear, 86, 314a, 314b Pin, 90 Oil pump, 100 Electric wheel, 110 Shaft, 111, 120, 121 Oil passage, 112 Oil , 130 Oil reservoir, 140, 150 damper, 160, 170 Ball joint, 180, 180a, 180b Knuckle, 200 Wheel support device, 210 Upper arm, 220 Lower arm, 230 Shock absorber, 250 Tire, 260, 270 Spring, 300, 300a , 300b torque rod, 310a, 310b arm, 312a, 312b bearing, IWM in-wheel motor.

Claims (6)

An elastic member attached to a load member provided in a wheel of the wheel and arranged to attenuate the vibration of the wheel and the vibration of the load member;
Meanwhile a suspension arm having one end fixed to the vehicle body to be rotatable in the vertical direction of the vehicle body,
A rotation support member connected to the other end of the suspension arm by a joint and connected to the elastic member , and rotatably supporting the wheel of the wheel;
A regulating member that regulates the movement locus of the load member so that the center of gravity of the load member reciprocates on a straight line passing through the position of the center of gravity of the load member in a state where the vibration of the wheel is stationary,
The load member is
A motor,
An output shaft for outputting power generated by the motor;
A constant velocity is attached to the output shaft so that the motor can be displaced in a direction along the output shaft according to the reciprocating motion of the center of gravity of the load member, and the rotation of the output shaft is transmitted to the wheel. Joints,
A case that is attached to the rotation support member via the elastic member, and that houses the motor;
When the output shaft swings around the constant velocity joint portion, the motor also swings so that the rotation shaft of the motor swings according to the swing of the output shaft,
The regulating member is
A pair of torque rods provided on both sides of the load member in parallel with the straight line;
A pair of arms movably attached in a direction along each of the pair of torque rods,
The case is a wheel support device in which the load member is attached to the arm so as to be rotatable about an axis orthogonal to both the output shaft and a straight line passing through the center of gravity of the load member. A pair of pins that support the motor on both sides;
The wheel support device according to claim 1, further comprising a pair of bearings respectively attached to the pair of arms that rotatably support the pair of pins. The load member is
The wheel support device according to claim 1, further comprising a transmission that changes the rotation speed of the motor at a predetermined ratio and transmits the change to the output shaft. The motor includes a hollow rotor;
The motor is disposed between the transmission and the rotation support member;
The wheel support device according to claim 3, wherein the output shaft extends from the transmission side through the hollow portion of the rotor toward the rotation support member. The suspension arm is
Lower arm,
Including an upper arm,
The elastic member is
A first elastic member provided between an end of the lower arm and the case;
The wheel support device according to any one of claims 1 to 4, comprising a second elastic member provided between an end of the upper arm and the case.   The wheel support device according to claim 5, wherein the first and second elastic members are provided on a straight line passing through the center of gravity.

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