JP2010190285A - Driving force distributing mechanism for differential gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving force distributing mechanism for a differential gear capable of assisting driving force of a vehicle in addition to assist and restriction in a turn of a vehicle. <P>SOLUTION: First elements of each pair of planetary carriers, ring gears and sun gears of first and second planetary gear mechanisms PR and PL of a differential gear D are respectively connected to two output elements 13R and 13L, and both of second elements are connected to an input element 18, uniting them not to turn relative to each other, and both of third elements are connected to rotate in opposite directions to each other through gear mechanisms 21a-21d, 22R and 22L. With this structure, driving force of a vehicle is distributed to the two output elements 13R and 13L at an optional ratio to assist or restrict a turn by engaging the first clutch C1 to drive the third elements in opposite directions to each other by a motor generator MG, and further, driving force of the vehicle can be assisted by engaging the second clutch C2 to drive the input element 18 by the motor generator MG. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a driving force distribution mechanism for a differential device that distributes a driving force applied to an input element of the differential device to two output elements at a predetermined ratio.

  The differential device arranged between the engine and the left and right wheels is composed of a pair of planetary gear mechanisms, the driving force of the engine is input to both ring gears, both planetary carriers are connected to the left and right wheels, and both sun gears are A driving force distribution mechanism for a differential device that assists or suppresses turning by distributing the driving force of the engine to the left and right wheels at an arbitrary ratio by being connected to a hydraulic motor or an electric motor and driven in opposite directions. Is known from Patent Document 1 below.

JP-A-6-297777

  By the way, in the above-mentioned conventional one, it is possible to assist or suppress the turning of the vehicle left and right by driving the driving source consisting of a hydraulic motor or an electric motor in the normal direction or the reverse direction. It was not possible to assist with the power source or to recover the kinetic energy of the vehicle body as electric energy by regenerative braking of the drive source.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to enable assist of driving force of a vehicle in addition to assisting or suppressing turning of the vehicle in a driving force distribution mechanism of a differential device. .

  To achieve the above object, according to the first aspect of the present invention, the driving force distribution of the differential device that distributes the driving force applied to the input elements of the differential device to the two output elements at a predetermined ratio. A first planetary gear mechanism comprising a first ring gear, a first sun gear, a first planetary carrier supporting a first pinion meshing with the first ring gear and the first sun gear, and a second ring gear; A second planetary gear mechanism including a second sun gear and a second planetary carrier that supports a second pinion meshing with the second ring gear and the second sun gear, and each of the pair of planetary carriers, the ring gear, and the sun gear. A first element of which is connected to each of the two output elements, and a second element is connected to the input element in a relatively non-rotatable manner; The third elements are coupled via the gear mechanism so as to rotate in opposite directions to each other, the driving source, the first clutch for connecting the gear mechanism to the driving source, and the input element for the input element. A second clutch connected to a drive source, engaging the first clutch to drive the third element in opposite directions, and engaging the second clutch to drive the input element A driving force distribution mechanism for a differential device is proposed.

  The right shaft 13R and the left shaft 13L of the embodiment correspond to the output element of the present invention, and the first and second planetary carriers 14R and 14L of the embodiment correspond to the first element of the present invention. The first and second ring gears 15R, 15L of the embodiment correspond to the second element of the present invention, and the first and second sun gears 16R, 16L of the embodiment correspond to the third element of the present invention. The external gear 18 of the form corresponds to the input element of the present invention, and the first gear 21a to the fourth gear 21d and the first and second external gears 22R and 22L of the embodiment correspond to the gear mechanism of the present invention. The motor generator MG of the embodiment corresponds to the drive source of the present invention.

  According to the configuration of the first aspect, the first element of each pair of planetary carrier, ring gear and sun gear of the first and second planetary gear mechanisms of the differential gear is coupled to the two output elements, respectively, and the first The two elements are coupled to each other so as not to rotate relative to each other and connected to the input element, and the third elements are coupled to each other via the gear mechanism so as to rotate in opposite directions. By driving the third element in the opposite directions with the driving source, the driving force of the vehicle can be distributed to the two output elements at an arbitrary ratio to assist or suppress turning, and the second clutch can be engaged. In addition, the driving force of the vehicle can be assisted by driving the input element with the driving source.

The figure which shows the structure of the drive force distribution mechanism of a differential apparatus. The figure explaining the function of the driving force distribution mechanism of a differential device.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2.

  FIG. 1 shows an application of a driving force distribution mechanism of a differential gear according to an embodiment of the present invention to a front engine / front drive vehicle. As shown in the figure, a transmission M is connected to an engine E mounted horizontally on a vehicle body, and a differential input shaft 11 which is an output shaft of the transmission M is connected to a planetary gear type differential D. An input gear 12 for transmitting driving force is provided.

  The differential device D includes a right first planetary gear mechanism PR connected to the right shaft 13R for driving the right wheel WR and a left second planetary gear mechanism PL connected to the left shaft 13L for driving the left wheel WL. Both planetary gear mechanisms PR and PL are formed symmetrically with respect to the center line of the vehicle body, and a pair of left and right first and second planetaries fixed to the right shaft 13R and the left shaft 13L as two output elements, respectively. Carriers 14R and 14L, a pair of left and right first and second ring gears 15R and 15L formed integrally, and a pair of left and right first and second sun gears 16R rotatably supported on the right shaft 13R and the left shaft 13L. , 16L, and a plurality of first and second pinions that are rotatably supported by the planetary carriers 14R, 14L and simultaneously mesh with the first and second ring gears 15R, 15L and the first and second sun gears 16R, 16L. 17R... 17L. The external gear 18 as one input element formed integrally with the first and second ring gears 15R and 15L meshes with the input gear 12.

  The first drive shaft 20 is connected to a motor / generator MG capable of driving and regenerative braking via a reduction gear 31 made of a planetary gear mechanism and a first clutch C1. The speed reducer 31 includes a sun gear 33 fixed to the rotation shaft 32 of the motor / generator MG, a planetary carrier 34 fixed to the first drive shaft 20, and a plurality of pinions rotatably supported by the planetary carrier 34. And a ring gear 37 fixed to the casing 36, and the pinions 35 mesh with the sun gear 33 and the ring gear 37 at the same time. Therefore, in the state where the first clutch C <b> 1 is engaged, the rotation of the rotation shaft 32 of the motor / generator MG is decelerated by the reduction gear 31 and transmitted to the first drive shaft 20.

  A first gear 21a is fixed to the first drive shaft 20, and the first gear 21a meshes with a first external gear 22R formed integrally with the first sun gear 16R. A second drive shaft 23 connected to the first drive shaft 20 via a third gear 21c and a fourth gear 21d is fixed with a second gear 21b. The second gear 21b is connected to the second sun gear. It meshes with a second external gear 22L formed integrally with 16L. The third and fourth gears 21c and 21d connecting the first drive shaft 20 and the second drive shaft 23 have the same number of teeth, and therefore the first drive shaft 20 and the second drive shaft 23 are the same. It rotates in the reverse direction at the number of rotations. The first and second gears 21a and 21b have the same number of teeth, and the first and second external gears 22R and 22L also have the same number of teeth. Therefore, the first clutch C1 is engaged. When the motor / generator MG is driven in this state, the first and second sun gears 16R and 16L rotate in the reverse direction at the same rotational speed.

  A third drive shaft 24 is arranged coaxially with the first and second drive shafts 20 and 23. A fifth gear 21e and a sixth gear 21f are fixed to the third drive shaft 24, and a second clutch C2 is disposed between the fifth and sixth gears 21e and 21f. The fifth gear 21e meshes with a seventh gear 21g fixed between the first clutch C1 and the speed reducer 31 of the first drive shaft 20, and the sixth gear 21f meshes with the external gear 18.

  Next, the operation of the embodiment of the present invention having the above configuration will be described with reference to FIG.

  (1) When both the first clutch C1 and the second clutch C2 are disengaged, the first and second external gears 22R and 22L integrated with the first and second sun gears 16R and 16L Since the two drive shafts 20 and 23 and the first to fourth gears 21a to 21d are connected to rotate in the reverse direction at the same rotational speed, the differential device D exhibits only a normal differential function.

  (2) The motor in a state where the first clutch C1 is engaged to connect the motor / generator MG to the first drive shaft 20 and the second clutch C2 is disengaged to allow differential of the differential device D. When the generator MG is driven, the first and second external gears 22R and 22L integrated with the first and second sun gears 16R and 16L are driven in the opposite directions at the same rotational speed, so that the motor generator MG A differential rotation is generated in the left and right shafts 13R and 13L according to the rotation direction, and the driving force of the engine E can be distributed to the left wheel WL and the right wheel WR at an arbitrary ratio. Therefore, if the driving force distributed to the turning outer wheel is made larger than the driving force distributed to the turning inner wheel, the turning performance of the vehicle can be improved, and conversely, the driving force distributed to the turning outer wheel is distributed to the turning inner wheel. If the driving force is less than the applied driving force, the straight running stability performance of the vehicle can be enhanced.

  (3) If the motor / generator MG is regeneratively braked with the first clutch C1 engaged and the second clutch C2 disengaged, the regenerative braking force generated by the motor / generator MG is changed to the differential device D. Thus, it is possible to stabilize the vehicle behavior by generating a yaw moment that prevents the vehicle from turning during deceleration of the vehicle.

  (4) In addition, the motor generator MG is opened (the coil current can be cut off and the motor can be rotated without load) while the first clutch C1 is engaged and the second clutch C2 is not engaged. In this case, the first clutch C1 is disengaged, and the differential device D exhibits only a normal differential function.

  (5) State in which the first clutch C1 is disengaged to separate the motor / generator MG from the first drive shaft 20, and the second clutch C2 is engaged to connect the fifth gear 21e and the sixth gear 21f. When the motor / generator MG is driven, the driving force of the motor / generator MG is input to the external gear 18 of the differential device D through the path of the seventh gear 21g, the fifth gear 21e, the second clutch C2, and the sixth gear 21f. Therefore, the driving force of the engine E can be assisted by the driving force of the motor / generator MG.

  At this time, if the engine E is stopped, the vehicle can be started or run only by the driving force of the motor / generator MG.

  (6) If the motor / generator MG is regeneratively braked with the first clutch C1 disengaged and the second clutch C2 engaged, the motor / generator MG is connected to the differential device D when the vehicle decelerates. Then, regenerative braking is performed, and the kinetic energy of the vehicle body can be recovered as electric energy.

  (7) If the motor / generator MG is opened while the first clutch C1 is disengaged and the second clutch C2 is engaged, the second clutch C2 is disengaged. Thus, the differential device D exhibits only a normal differential function.

  (8) The first clutch C1 is engaged to connect the motor / generator MG to the first drive shaft 20, and the second clutch C2 is engaged to integrally form the fifth gear 21e and the sixth gear 21f. When the motor / generator MG is driven in the coupled state, the first and second external gears 22R and 22L integrated with the first and second sun gears 16R and 16L are driven in the opposite directions at the same rotational speed. A differential rotation is generated in the left and right shafts 13R and 13L according to the rotation direction of the motor / generator MG, and the driving force of the engine E can be distributed to the left wheel WL and the right wheel WR at an arbitrary ratio.

  However, in this case, since both the engine E and the motor / generator MG are connected to the external gear 18 of the differential device D, the rotation direction of the motor / generator MG is limited to the same direction as the rotation direction of the engine E. The motor / generator MG cannot be rotated in the reverse direction. Therefore, the distribution of the driving force to the left wheel WL and the right wheel WR is limited to turning assist when turning right, and it is difficult to actually use it.

  As described above, according to the present embodiment, the driving force of the engine E can be distributed to the right shaft 13R and the left shaft 13L at an arbitrary ratio simply by adding one motor / generator MG to the differential device D. In addition to assisting or suppressing the turning, driving assist and deceleration assist of the vehicle can be realized by driving or braking the input gear 12 with the motor / generator MG.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the roles of the three elements constituting the planetary gear mechanisms PR and PL, that is, the roles of the planetary carriers 14R and 14L, the ring gears 15R and 15L, and the sun gears 16R and 16L can be arbitrarily replaced.

  The driving force distribution mechanism of the present invention is not limited to the front wheel drive system of the front drive vehicle described in the embodiment, but the rear wheel drive system of the front drive vehicle, the rear wheel drive system of the rear drive vehicle, or the rear drive. It can also be applied to the drive system of the front wheels of a car.

  In the embodiment, the motor / generator MG is used as the drive source, but a hydraulic motor can be used instead of the motor / generator MG. However, in this case, it is impossible to recover energy by regenerative braking.

13R Right shaft (output element)
13L left shaft (output element)
14R First planetary carrier (first element)
14L Second planetary carrier (first element)
15R first ring gear (second element)
15L second ring gear (second element)
16R first sun gear (third element)
16L 2nd sun gear (3rd element)
17R 1st pinion 17L 2nd pinion 18 External gear (input element)
21a First gear (gear mechanism)
21b Second gear (gear mechanism)
21c 3rd gear (gear mechanism)
21d Fourth gear (gear mechanism)
22R First external gear (gear mechanism)
22L Second external gear (gear mechanism)
C1 First clutch C2 Second clutch D Differential device MG Motor generator (drive source)
PR 1st planetary gear mechanism PL 2nd planetary gear mechanism

Claims (1)

A driving force distribution mechanism for a differential device that distributes the driving force applied to the input element (18) of the differential device (D) to the two output elements (13R, 13L) at a predetermined ratio,
A first ring gear (15R), a first sun gear (16R), a first planetary carrier (14R) supporting a first pinion (17R) meshing with the first ring gear (15R) and the first sun gear (16R); A first planetary gear mechanism (PR), a second ring gear (15L), a second sun gear (16L), and a second pinion (17L) meshing with the second ring gear (15L) and the second sun gear (16L). ) And a second planetary gear mechanism (PL) composed of a second planetary carrier (14L) for supporting the pair of planetary carriers (14R, 14L), ring gears (15R, 15L) and sun gears (16R, 16L). ) Are coupled to the two output elements (13R, 13L), respectively, and the second element (14R, 14L) The elements (15R, 15L) are coupled to each other so as not to rotate relative to each other and connected to the input element (18), and the third elements (16R, 16L) are coupled to each other via a gear mechanism (21a to 21d, 22R, 22L). Are connected to rotate in opposite directions,
A drive source (MG), a first clutch (C1) for connecting the gear mechanisms (21a to 21d, 22R, 22L) to the drive source (MG), and the input element (18) as the drive source (MG) A second clutch (C2) connected to
The first clutch (C1) is engaged to drive the third elements (16R, 16L) in opposite directions, and the second clutch (C2) is engaged to engage the input element (18). A driving force distribution mechanism for a differential device, characterized by being driven.

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