JP2005178603A - Wheel structure for electric vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel structure for an electric vehicle of in-wheel motor type allowing miniaturizing of the whole constitution. <P>SOLUTION: The wheel structure 10 for the electric vehicle including a motor 20 in a wheel 1 comprises a speed reduction mechanism 70 for reducing rotation speed of the motor 20 and transmitting it to the wheel and a brake mechanism. A brake pad 84a of the brake mechanism is arranged so as to act on both surfaces 76a of a ring gear 76 of the speed reduction mechanism 70. Thus, the ring gear 76 of the speed reduction mechanism 70 is made to function as a brake disk, thereby miniaturizing the whole constitution of the wheel structure for the electric vehicle having the speed reduction mechanism and the brake mechanism. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a wheel structure for an electric vehicle including a motor in a wheel.

Conventionally, an electric speed reducer in which a planetary speed reduction mechanism is integrated with a disc brake device is known (see, for example, Patent Document 1). In this conventional electric speed reducer, the planetary speed reduction mechanism and the disk brake device are integrated by connecting the disk to the internal gear of the planetary speed reduction mechanism via a connecting member.
JP 2003-176856 A

  However, when the conventional electric speed reducer is applied as a speed reduction mechanism for an in-wheel motor type electric vehicle wheel structure, since the disk is provided separately from the internal gear of the planetary speed reduction mechanism, the overall configuration is large. There is a problem that the mountability is bad.

  Then, it aims at provision of the wheel structure for electric vehicles of an in-wheel motor type which can miniaturize the whole structure.

In order to solve the above problems, according to one aspect of the present invention, in a wheel structure for an electric vehicle including a motor at least partially in a wheel,
A deceleration mechanism that decelerates the rotation of the motor and transmits it to the wheels;
A brake mechanism,
A wheel structure for an electric vehicle is provided in which brake pads of the brake mechanism are arranged so as to act on both surfaces of the gear of the speed reduction mechanism.

  According to this aspect, since the gear of the speed reduction mechanism can function as a brake disc, the overall configuration can be downsized compared to the configuration in which the brake disc is provided separately from the speed reduction mechanism. In this aspect, the motor may be completely included in the wheel or may be partially included.

  In this aspect, the gear on which the brake pad acts is spline-connected to the wheel, can be rotated integrally with the wheel, and can be attached to and detached from the wheel in the vehicle inside / outside direction. Thereby, the maintainability of the gear as a brake disk becomes very good.

  According to the present invention, the entire configuration of the wheel structure for an electric vehicle including the speed reduction mechanism and the brake mechanism can be reduced in size by causing the gear of the speed reduction mechanism to function as a brake disk.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view of an essential part showing a wheel structure for an electric vehicle according to an embodiment of the present invention. The wheel structure 10 for an electric vehicle according to the present embodiment is applied to an in-wheel motor type electric vehicle. A motor 20 for driving the wheel is disposed inside the wheel 1. The motor 20 is disposed for each drive wheel. Since the configuration of the present embodiment is not substantially different for each drive wheel, only one drive wheel will be described below. However, the configuration of the present embodiment may be applied only to the front wheel side or only to the rear wheel side.

  A hub 2 is fixed to the wheel 1 by a hub bolt 90. The hub 2 is rotatably supported by a non-rotating portion (for example, a housing constituting the stator portion) of the motor 20 via a bearing (not shown). For example, when the motor 20 is an inner rotor type motor, the hub 2 may be supported via a bearing on the outer housing of the motor 20 inside the motor 20, and the motor 20 is an outer rotor type motor. The inner housing of the motor 20 (wheel center side) may be supported by the inner housing of the motor 20 via a bearing.

  The hub 2 performs a function of receiving vertical force and lateral force acting on the wheel 1 (including the tire) in cooperation with the bearing. In order to perform this function, the bearing may be a single-row four-point contact type bearing, or may be a double-row angular bearing that performs a similar function.

  A speed reduction mechanism 70 is disposed outside the motor 20 (between the motor 20 and the wheel 1). The speed reduction mechanism 70 functions to reduce the rotation of the motor 20 at a predetermined speed reduction ratio and transmit it to the wheel 1. As shown in FIG. 1, the speed reduction mechanism 70 is completely included in the wheel 1, but the motor 20 may be completely included or partially included in the wheel 1. Good (for example, a configuration in which the main body of the motor 20 is disposed outside the wheel 1 and only the output shaft of the motor 20 connected to the speed reduction mechanism 70 is disposed in the wheel 1).

  2 is a cross-sectional view taken along the line AA of FIG. The speed reduction mechanism 70 includes a sun gear 72 that constitutes the output shaft of the motor 20. The sun gear 72 has an annular shape and includes a hollow portion through which the shaft portion of the hub 2 is inserted. A pinion gear 74 is meshed with the sun gear 72. In the present embodiment, four pinion gears 74 are arranged around the sun gear 72 at equal intervals. Each pinion gear 74 is rotatable around a pin 74a, and the pin 74a is fixed to a non-rotating portion of the motor 20, as shown in FIG. In addition, when the motor 20 is an inner rotor type motor, the pin 74a may be fixed to the outer housing of the motor 20, and when the motor 20 is an outer rotor type motor, the pin 74a is further further than the outer housing. You may fix to the 3rd housing set to a radial direction outer side. In the former case, the suspension arm attachment portion may be set in the outer housing constituting the non-rotating portion. In the latter case, the third housing is supported by the outer housing via a bearing, and a mounting portion for the suspension arm may be set.

  FIG. 3 is a detailed view of a portion X in FIG. A ring gear 76 is engaged with the pinion gear 74. The ring gear 76 is connected to the wheel 1 so as to transmit substantially only rotational force. Specifically, the connection between the ring gear 76 and the wheel 1 is realized by spline connection (connection by fitting of a plurality of corresponding grooves). The spline portion (a plurality of grooves extending in the vehicle inside / outside direction) 1b on the wheel 1 side may be integrally formed on the inner peripheral surface of the rim 1a of the wheel 1 or on the inner peripheral surface of the rim 1a of the wheel 1 It may be combined as a separate part. The spline portion 1b on the wheel 1 side and the corresponding spline portion 77 on the outer periphery of the ring gear 76 are not necessarily set over the entire circumferential direction as long as the ring gear 76 and the wheel 1 are rotated together. There is no need. In the configuration as described above, the rotation of the motor 20 is transmitted from the sun gear 72 to the wheel 1 via the pinion gear 74 and the ring gear 76.

  Here, referring to FIGS. 1 and 2 again, the ring gear 76 of this embodiment constitutes a brake disc (disc rotor) of the brake mechanism. Specifically, the ring gear 76 is made of a material (typically cast iron) used for a brake disc. The brake caliper 84 is disposed so as to sandwich the sliding surface 76a of the ring gear (disk rotor) 76 from the inner peripheral side thereof. The circumferential position of the brake caliper 84 is set between two adjacent ring gears 76 so that the bridge 84b of the brake caliper 84 passes between the inner peripheral side of the ring gear 76 and the outer peripheral surface of the motor 20. Composed. The position of the brake caliper 84 in the circumferential direction is not limited to the position in the vertical direction as shown in FIGS. 1 and 2, and may be set between two other adjacent ring gears 76.

  The brake caliper 84 communicates with the master cylinder via a hydraulic pressure passage (not shown). When a predetermined hydraulic pressure is supplied to the hydraulic cylinder of the brake caliper 84, the pad 84a of the brake caliper 84 is driven so as to sandwich both sliding surfaces 76a of the ring gear 76, and the braking function is realized by the friction force at that time. The

  Thus, in this embodiment, the gear of the speed reduction mechanism 70 (in this example, the ring gear 76) is used as a brake disk (disk rotor). Therefore, according to the present embodiment, the entire configuration including the brake mechanism and the speed reduction mechanism 70 (including the motor 20) can be reduced in size, and the entire configuration can be effectively performed in a limited space in the wheel 1. Can be established. Thereby, the design freedom of the other member mounted in the wheel 1 increases.

  In the present embodiment, as described above, since the hub 2 is responsible for most of the lateral force acting on the wheels, no large lateral force acts on each gear (particularly the ring gear 76) of the speed reduction mechanism 70. (Note that the deceleration mechanism 70 and the brake mechanism receive braking torque during braking and regenerative torque of the motor 20). In particular, when the ring gear 76 and the wheel 1 are spline-connected as described above, the lateral force does not substantially act on the ring gear 76. For this reason, in this embodiment, the ring gear 76 is simply clamped by the pad 84a of the brake caliper 84, but the movement of the ring gear 76 in and out of the vehicle can be restricted (restrained). That is, the ring gear 76 can be supported only by the brake caliper 84 without using a bearing or the like. As a result, the maintainability (same assembling property) of the brake mechanism (particularly the ring gear 76 as a disk rotor) is improved. That is, since the ring gear 76 is only splined to the wheel 1, it can be attached and detached in the vehicle interior / exterior direction after the brake caliper 84 is removed.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the embodiment described above, the ring gear 76 is detachably connected to the wheel 1 by spline connection, but the present invention does not exclude the configuration in which the ring gear 76 and the wheel 1 are coupled. . For example, a configuration in which the ring gear 76 is coupled to the wheel 1 with a bolt or the like, or a configuration in which a gear corresponding to the ring gear 76 is integrally formed on the inner peripheral surface of the rim 1a of the wheel 1 may be employed. . Even in such a case, the maintainability of the ring gear 76 is deteriorated, but the entire configuration including the brake mechanism and the speed reduction mechanism 70 can still be reduced in size.

  In the above-described embodiment, the ring gear 76 is restrained from moving in and out of the vehicle only by the pad 84a of the brake caliper 84. However, in the present invention, the ring gear 76 is not limited to the brake caliper 84 but by other members. It does not exclude the configuration that supports For example, the ring gear 76 has an extension portion that extends to the inside of the vehicle, and the extension portion may be a deep groove ball bearing of a single-row, small-diameter ball through a bearing (in this case, a non-groove ball bearing). You may be supported by the rotation part.

  In the above-described embodiment, the hub 2 has a function of receiving a lateral force. However, the present invention does not exclude the configuration in which the deceleration mechanism 70 shares the lateral force. For example, as described above, the ring gear 76 has an extension that extends to the inside of the vehicle, and the extension extends via a bearing (for example, a single-row four-point contact type bearing or a double-row angular bearing). And may be supported by a non-rotating portion of the motor 20.

  The brake caliper 84 shown in FIG. 1 is a hydraulically driven caliper, but may be any type of caliper, and may be any type of caliper such as a caliper fixed type or a caliper floating type. May be.

It is principal part sectional drawing which shows the wheel structure for electric vehicles by one Example of this invention. It is AA sectional drawing of FIG. FIG. 3 is a detailed view of a portion X in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wheel 1a Rim 1b Spline part 2 Hub 10 Wheel structure for electric vehicles 20 Motor 70 Deceleration mechanism 72 Sun gear 74 Pinion gear 74a Pin (rotary shaft)
76 Ring gear 76a Sliding surface 77 Spline part
84 Brake caliper 84a Pad 90 Hub bolt

Claims (2)

In a wheel structure for an electric vehicle including a motor at least partially in the wheel,
A deceleration mechanism that decelerates the rotation of the motor and transmits it to the wheels;
A brake mechanism,
A wheel structure for an electric vehicle, wherein the brake pads of the brake mechanism are arranged so as to act on both surfaces of the gear of the speed reduction mechanism.   2. The wheel structure for an electric vehicle according to claim 1, wherein the gear on which the brake pad acts is spline connected to the wheel, can rotate integrally with the wheel, and can be attached to and detached from the wheel in an inward / outward direction of the vehicle. .

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