JP2005238989A - Motor drive system of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor drive system of a vehicle having a motor to drive wheels and capable of compatibly ensuring the riding comfort and the running performance and expanding the space for cabin/cargo rooms of a vehicle with a suspension in which the positional relationship between a turnable arm and a knuckle is not changed. <P>SOLUTION: A motor 3 to drive a hub shaft 2 of a wheel 1 employing a trailing arm type suspension in which the positional relationship between a trailing arm 4 and a knuckle 9 is not changed is turnably mounted on a rotary shaft 13 concentric with a rotary shaft 11 of the trailing arm 4, and the driving force of the motor 3 is transmitted to a hub shaft 2 supported by the knuckle via a driving force transmission mechanism to be turned together with the motor 3. The motor 3 is mounted on the upper side of the suspension and the driving force transmission mechanism has a simple configuration to compatibly ensure the ride quality and the running performance and to expand a space for a cabin/a cargo room. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention relates to a motor drive system for an automobile that employs a suspension device that includes a motor that drives a wheel and that does not change the positional relationship between a rotating arm that supports the wheel axle of the motor-driven wheel and a knuckle.

  There are two types of automobile suspension systems: an independent suspension system in which the axles of the wheels connected to the universal joint are independently suspended, and an axle suspension system in which the axles of the left and right wheels including the differential unit are suspended integrally. . In addition, a suspension device that does not change the positional relationship between the rotating arm and the knuckle, such as a trailing arm method, is employed for the wheels that are not steered.

  On the other hand, the motor drive system of an automobile that drives a wheel by a motor is a so-called in-wheel type system in which a motor and a gear reduction mechanism are directly connected to an axle, and the motor and the gear reduction mechanism are suspended together with an axle by a suspension device. (For example, refer to Patent Document 1) Or, by connecting a motor and a transmission to a differential device, the drive shaft on the differential device side and the drive shaft on the wheel side (axle) can be freely set as in the conventional engine drive type. There exists what was connected with the joint (for example, refer to patent documents 2).

JP 2002-247713 (page 4-7, Fig. 1-2) JP 2003-72392 A (page 2-4, FIG. 2-3)

  The in-wheel type motor drive system described in Patent Document 1 does not require a differential device or a universal joint, and has the advantage that the drive force transmission mechanism can be slimmed and expansion of the room / loading room space can be expected. Since the gear reduction mechanism is suspended by the suspension device together with the axle, there is a problem in that unsprung weight increases and riding comfort and running performance deteriorate. In addition, there is a problem that the mounting environment is bad such that the motor is directly subjected to a shock due to unevenness of the road surface.

  On the other hand, the motor drive system of the type in which the motor and the transmission are connected to the differential device described in Patent Document 2 does not increase the unsprung weight by adopting the independent suspension type suspension device. There is a problem that the force transmission mechanism becomes large and the room / loading room space cannot be expanded.

  Therefore, an object of the present invention is to secure riding comfort and traveling performance and to provide a room / loading room space for an automobile that employs a suspension device that includes a motor for driving wheels and that does not change the positional relationship between the rotating arm and the knuckle. It is to balance the expansion.

  In order to solve the above-mentioned problems, the present invention provides a motor vehicle that employs a suspension device that includes a motor that drives a wheel and that does not change the positional relationship between a rotating arm that supports the wheel axle of the motor and the knuckle. In the motor drive system, the motor is rotatably attached to a rotary shaft coaxial with the rotary shaft of the rotary arm, and the driving force of the motor is transmitted via a driving force transmission mechanism that rotates together with the motor. Thus, a structure for transmitting to the axle supported by the knuckle is adopted.

  That is, a motor that drives a wheel axle that employs a suspension device in which the positional relationship between the rotating arm and the knuckle does not change is rotatably mounted on a rotating shaft that is coaxial with the rotating shaft of the rotating arm. Is transmitted to the axle supported by the knuckle through a driving force transmission mechanism that is rotated together with the motor, and the motor is attached to the upper side of the suspension device, and the driving force transmission mechanism is As a simple configuration, it is possible to ensure both ride comfort and driving performance while expanding the room and cargo space.

  When the driving force transmission mechanism includes a gear transmission mechanism that also serves as a reduction mechanism, or a gear reduction mechanism and a gear transmission mechanism, the motor can be reduced in size.

  The motor drive system for an automobile of the present invention uses a motor that drives a wheel axle that employs a suspension device in which the positional relationship between the rotation arm and the knuckle does not change, as a rotation axis that is coaxial with the rotation axis of the rotation arm. It is attached so that it can rotate, and the driving force of this motor is transmitted to the axle supported by the knuckle through the driving force transmission mechanism that rotates together with the motor, and the motor is attached to the upper side of the suspension device. In addition, since the driving force transmission mechanism has a simple configuration, it is possible to ensure both ride comfort and traveling performance and expansion of the room / loading room space. In addition, it is possible to prevent the motor from directly receiving shocks due to road surface irregularities or the like, and to improve the mounting environment.

  When the driving force transmission mechanism includes a gear transmission mechanism that also serves as a reduction mechanism, or a gear reduction mechanism and a gear transmission mechanism, the motor can be reduced in size.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, this motor drive system for an automobile drives a hub shaft 2 that is an axle of left and right wheels 1 with a motor 3, and each hub shaft 2 serves as a rotating arm. A trailing arm type suspension device using an oil damper 6 with a trailing arm 4 and a coil spring 5 is suspended on a vehicle body 7. Each wheel 1 is a rear wheel that is not steered, and the positional relationship between the left and right trailing arms 4 connected by the torsion beam 8 and the knuckle 9 that rotatably supports the left and right hub shafts 2 does not change.

  The left and right trailing arms 4 are rotatably supported on a coaxial rotating shaft 11 via rubber bushes 10, and the left and right motors 3 are also coaxial with the rotating shaft 11 via rubber bushes 12. The upper rotating shaft 13 is rotatably attached.

  Each of the motors 3 has a speed reduction mechanism using a planetary gear, and a rotary shaft 14 is connected to the output shaft 3a. A tip of the rotary shaft 14 is connected to the gear 15a by spline coupling, and is perpendicular to the gear 15a. The meshing gear 15b is connected to the hub shaft 2 via a spline-coupled shaft coupling 16. The gear 15 a and the hub shaft 2 are rotatably supported on the knuckle 9 by angular ball bearings 17 and 18, respectively. A wheel 1 and a brake rotor 19 for a disc brake are fixed to the hub shaft 2 with bolts 20.

  Accordingly, the driving force of each motor 3 is transmitted from the output shaft 3a to the hub shaft 2 through a gear transmission mechanism using the rotary shaft 14 and the gears 15a and 15b. Instead of providing a reduction mechanism on the motor 3 side, a reduction ratio can be provided between the gears 15a and 15b.

  Each of the motors 3 and the driving force transmission mechanism described above rotate around a rotation shaft 13 coaxial with the rotation shaft 11 of each trailing arm 4, so that a constant velocity universal joint as conventionally provided is provided. The driving force is transmitted to each wheel 1 by smoothly following the direction of rotation of the trailing arm 4 that rotates with the vertical movement of the wheel 1 without using the above.

  In the above-described embodiment, the trailing arm type suspension device is employed, but the suspension device may be any device as long as the positional relationship between the rotating arm and the knuckle does not change, and other types of suspension devices may be employed. The brake mechanism is not limited to the disc brake using the brake rotor of the embodiment, and a drum brake can also be adopted.

Notched plan view showing an embodiment of an automobile motor drive system Sectional view along the line II-II in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wheel 2 Hub shaft 3 Motor 3a Output shaft 4 Trailing arm 5 Coil spring 6 Oil damper 7 Car body 8 Torsion beam 9 Knuckle 10 Rubber bush 11 Rotating shaft 12 Rubber bush 13 Rotating shaft 14 Rotating shaft 15a, 15b Gear 16 Shaft coupling 17, 18 Angular contact ball bearing 19 Brake rotor 20 Bolt

Claims (2)

  In a motor drive system for a motor vehicle that employs a suspension device that includes a motor that drives a wheel and that supports the axle of the wheel driven by the motor and the knuckle does not change, the pivot shaft of the pivot arm The motor is rotatably mounted on a rotation shaft coaxial with the motor, and the driving force of the motor is transmitted to the axle supported by the knuckle through a driving force transmission mechanism that rotates together with the motor. A motor drive system for an automobile characterized by that.   The motor drive system for an automobile according to claim 1, wherein the driving force transmission mechanism includes a gear transmission mechanism that also serves as a reduction mechanism, or a gear reduction mechanism and a gear transmission mechanism.

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