JP2014019336A - Vehicle drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle drive device that has a compact and simple structure without increasing number of components and weight and reduces mechanical loss, maintains efficient fuel consumption, makes right and left drive shafts equal in length and lengthens the drive shafts, without sacrificing: effect of power of the drive shafts on a constant-velocity joint; and a suspension stroke.SOLUTION: A front wheel drive part 5 comprises an electric motor 10, arranged between right and left wheels, that is composed of a stator 11 fastened to a transmission case 2 and a rotor 12 supported rotatably in the transmission case 2. In the rotor 12, a differential mechanism part 20 for operating differential action between one output shaft for outputting to one of left and right wheels 30L and 30R and the other output shaft for outputting to the other of the left and right wheels, is provided.

Description

  The present invention relates to a vehicle drive device that is driven by a driving force generated by an electric motor provided between left and right wheels.

  In recent years, various automobiles (electric automobiles, hybrid cars) that use an electric motor as a drive source have been developed and put into practical use. For example, in Japanese Patent Application Laid-Open No. 2002-160540 (hereinafter referred to as Patent Document 1), a differential that can engage with a gear-type transmission and an output shaft of the transmission and drive the drive wheels in accordance with the rotational force of the output shaft. And an electric motor having a rotating shaft that engages with the differential, the output shaft of the transmission, the driving shaft connected to the driving wheel, and the rotating shaft of the electric motor are arranged in parallel at different positions. In addition, a technology for a hybrid vehicle drive device is disclosed in which a gear formed on a differential case engages with a gear formed on an output shaft and also engages with a gear formed on a rotating shaft. In Japanese Patent Laid-Open No. 8-48164 (hereinafter referred to as Patent Document 2), a stator fixed to a motor case side of a case divided into a motor case and a gear case, and a rotor disposed on the radially inner side of the stator. And a motor having a rotor shaft splined to the rotor and rotatably supported on the case by a pair of ball bearings, and disposed on the gear case side coaxially with the rotor shaft, and the motor rotation is decelerated and output. There is disclosed a technology for a drive device for an electric vehicle that includes a planetary gear and a differential device that transmits the output of the planetary gear, one through the rotor shaft and the other directly to the left and right wheels of the vehicle.

JP 2002-160540 A JP-A-8-48164

  However, in the layout of the hybrid vehicle drive device disclosed in Patent Document 1 as described above, since the electric motor and the differential device are provided separately from each other, such as a gear for connecting them, etc. There is a problem that the connection structure and the bearing structure become complicated, resulting in an increase in weight and cost. In addition, in the layout of the electric vehicle drive device in which the motor and the differential mechanism disclosed in Patent Document 2 described above are connected in the vehicle width direction, the drive shaft is not particularly long and the suspension stroke is insufficient. In addition, there is a possibility that an external force is easily applied to the constant velocity joint interposed in the drive shaft. Further, the drive shafts also have unequal lengths on the left and right, and there is a problem that independent design of each shaft is required.

  The present invention has been made in view of the above circumstances, and does not increase the number of parts and weight, has a compact and simple configuration, has little mechanical loss, maintains good fuel consumption, and the left and right drive shafts, etc. It is an object of the present invention to provide a vehicle drive device that can be lengthened and the drive shaft can be made longer and does not sacrifice the influence of the force on the constant velocity joint of the drive shaft and the suspension stroke.

  According to an aspect of the present invention, there is provided a vehicle drive device including a stator fixed to a main case and an electric motor provided between left and right wheels including a rotor rotatably supported in the main case. A differential mechanism portion for performing a differential between one output shaft that outputs to one of the wheels and the other output shaft that outputs to the other of the left and right wheels is provided in the rotor.

  According to the vehicle drive device of the present invention, the number of parts and the weight are not increased, the structure is compact and simple, the mechanical loss is small, the fuel consumption is maintained, and the left and right drive shafts are made equal in length. The drive shaft can be made longer, and the effect of the force on the constant velocity joint of the drive shaft and the suspension stroke are not sacrificed.

1 is a schematic side view of a transmission according to an embodiment of the present invention. It is the skeleton figure seen from the front of the front wheel drive part concerning one embodiment of the present invention. It is principal part sectional explanatory drawing of the front-wheel drive part based on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The vehicle according to the embodiment of the present invention will be described by taking as an example a hybrid vehicle in which the front wheels are driven by a driving force generated by an electric motor and the rear wheels are driven by a driving force generated by an engine.

  In FIG. 1, reference numeral 1 denotes a transmission, and an engine 3 is connected to a front portion of a transmission case 2 of the transmission 1.

  A transmission mechanism unit 4 is housed in the transmission case 2 of the transmission 1, and a front wheel drive unit 5 is fixed to the front lower side of the transmission mechanism unit 4. The output shaft 3a from the engine 3 is connected to the speed change mechanism portion 4, and the output shaft 4a from the speed change mechanism portion 4 is connected to a rear wheel side drive shaft (not shown).

  As shown in FIGS. 2 and 3, the front wheel drive unit 5 includes an electric motor (electric motor) 10 and a differential mechanism unit 20, and the differential mechanism unit 20 includes a left front wheel 30 </ b> L and a left drive shaft 31 </ b> L. Are connected via a right front wheel 30R and a right drive shaft 31R. Constant velocity joints 32 and 33 are interposed in the left and right drive shafts 31L and 31R on the differential mechanism 20 side and on the wheels 21L and 21R, respectively.

  In the electric motor 10, a stator 11 is fixed to a transmission case 2 as a main case, and a differential mechanism portion 20 is integrally provided in the center of the rotor 12, and is rotatably supported by the transmission case 2.

  The differential mechanism unit 20 is integrally fixed to the central portion of the rotor 12 of the electric motor 10 by, for example, a differential case 21 being fitted or shrink-fitted with a predetermined dimensional tolerance, for example. . In the differential case 21, the pinion shaft 23 that is secured and fixed by the straight pin 22, the pair of differential bevel pinions 24 and 24 that are rotatably supported by the pinion shaft 23, and the differential bevel pinions 24 and 24 mesh with each other. In addition, a pair of left and right differential bevel gears (side gears) 25 and 25 connected to the left and right drive shafts 31L and 31R are provided.

  When the rotor 12 is rotated by the electric motor 10 in the front wheel drive unit 5 configured as described above, the differential mechanism unit 20 is also rotated, and the left and right front wheels 30L, As a result, the driving force generated by the electric motor 10 is transmitted to the left and right front wheels 30L and 30R.

  Here, if a differential rotation occurs between the left and right wheels due to a vehicle turning or a change in the left and right road surface condition, the difference in rotation speed is appropriately distributed by the differential function of the differential mechanism unit 20 and Appropriate differential rotation occurs between the outer wheel and the turning inner wheel, and the road surface is properly gripped to enable stable traveling.

  As described above, the front wheel drive unit 5 according to the embodiment of the present invention includes the electric motor 10 provided between the left and right wheels including the stator 11 fixed to the transmission case 2 and the rotor 12 rotatably supported in the transmission case 2. The rotor 10 is provided with a differential mechanism section 20 for performing a differential between one output shaft that outputs to one of the left and right wheels 30L and 30R and the other output shaft that outputs to the other of the left and right wheels. For this reason, the front wheel drive unit 5 is configured such that the electric motor 10 and the differential mechanism unit 20 are integrally formed, and there is no need for a connecting structure such as a gear or a bearing structure for connecting these, and the structure can be simplified, and the weight can be simplified. It can be configured without an increase or cost increase.

  Further, since the differential mechanism portion 20 is integrally provided in the rotor 12 of the electric motor 10, the left and right drive shafts 31L and 31R are made to have sufficiently long shafts without unequal lengths. It is possible to secure a sufficient suspension stroke (Lst in FIG. 2), and it is also possible to prevent unnecessary force from acting on the constant velocity joints 32 and 33.

  In addition, the front wheel drive unit 5 according to the embodiment of the present invention can be disposed in the space where the conventional hypoid gear-differential device is disposed. The electric motor 10 can also be adopted, and it is possible to generate a sufficient driving force. Furthermore, since the front wheel drive unit 5 according to the embodiment of the present invention can be disposed in a space where the conventional hypoid gear-differential device is disposed, not only a horizontally mounted engine but also a vertically mounted type. Even this engine can be easily adopted.

  Further, since the front wheel drive unit 5 according to the embodiment of the present invention integrally includes the differential mechanism unit 20 in the rotor 12 of the electric motor 10, an unnecessary support member is not provided on the shaft core portion of the rotor 12. The rotor 12 can be easily rotatably supported, and an increase in weight can be suppressed.

  In the embodiment of the present invention, the rear wheel is driven by the driving force generated by the engine 3 and the front wheel is driven by the driving force generated by the electric motor 10. However, it goes without saying that it can also be applied to the rear wheels. If the driving device according to the present embodiment is used for the front wheels and the rear wheels, an all-wheel drive electric vehicle can be easily realized. The present invention can also be applied to a hybrid vehicle in which the rear wheels are driven by the driving force generated by the electric motor 10 and the front wheels are driven by the driving force generated by the engine.

  Furthermore, although the differential mechanism unit 20 of the front wheel drive unit 5 according to the embodiment of the present invention has been described by taking a configuration having a differential function as an example, even if it has a known differential limiting function, etc. It goes without saying that the invention can be applied.

1 Transmission 2 Transmission case (main case)
3 Engine 4 Transmission mechanism 5 Front wheel drive 10 Electric motor (electric motor)
DESCRIPTION OF SYMBOLS 11 Stator 12 Rotor 20 Differential mechanism part 21 Differential case 22 Straight pin 23 Pinion shaft 24 Differential bevel pinion 25 Differential bevel gear 30L, 30R Front wheel 31L, 31R Drive shaft 32 Constant velocity joint 33 Constant velocity joint

Claims (3)

In a vehicle drive device provided with an electric motor provided between a left and right wheel composed of a stator fixed to a main case and a rotor rotatably supported in the main case,
A vehicle drive characterized in that a differential mechanism portion for performing a differential between one output shaft that outputs to one of the left and right wheels and the other output shaft that outputs to the other of the left and right wheels is provided in the rotor. apparatus.   The main case is a transmission case, wherein the one output shaft is an output shaft that outputs to one of the left and right front wheels, and the other output shaft is an output shaft that outputs to the other of the left and right front wheels. The vehicle drive device according to claim 1.   The vehicle drive device according to claim 1, wherein the rotor is integrally provided on an outer periphery of a differential case of the differential mechanism portion.

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