JP2007285342A - Right and left drive force distribution device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a differential case and a differential mechanism, reduce the weights thereof, and reduce the costs thereof, facilitate the assembling operation for the differential mechanism, treat a high input load by increasing the outer diameter of a bearing member for support the differential case, and stabilize the function of distributing a drive force to right and left drive wheels by remarkably reducing the seizures of drive shafts to each other in the differential case. <P>SOLUTION: A bearing 29 is positioned by a snap ring 32 fitted to a crown gear 17, and the axial position of a planetary carrier 22 is determined by the crown gear 17. The planetary carrier 22 is supported at two contact points by the small diameter part 18A of the differential case 18 and a sun gear 23. The left end part of the planetary carrier 21 is arranged continuously with the outer peripheral surface of a left drive shaft 24, and the sun gear 23 is arranged continuously with the left shaft end of a right drive shaft 25. Consequently, the quantity of the positions where the right and left drive shafts 24, 25 are slid on each other in the differential case 18 can be remarkably reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a left / right driving force distribution device for a vehicle, and more particularly to a left / right driving force distribution device that distributes engine driving force to left and right driving wheels by a differential mechanism using a planetary gear set.

  2. Description of the Related Art Conventionally, as shown in FIG. 2, a right / left driving force distribution device 1 for this type of vehicle has a crown gear 4 that is rotatably supported in a housing 2 and meshes with a drive pinion gear 3 that transmits engine driving force. The integrated differential case 5, the driving force transmitted to the differential case 5, the planetary gear set 6, that is, the internal gear 7 formed inside the differential case 5, a plurality of planetary gears 8 meshing with the internal gear 7, a plurality of The planetary carrier 9 that rotatably supports the planetary gear 8, the sun gear 10 that meshes with the plurality of planetary gears 8, the left drive shaft 11 that is connected to the sun gear 10, and the right drive shaft 12 that is connected to the planetary carrier 9 are distributed to the left and right drive wheels. And a differential mechanism 13 (see, for example, Patent Document 1).

  The left / right driving force distribution device 1 evenly distributes the driving force transmitted to the differential case 5 via the planetary gear 8 to the planetary carrier 9 and the sun gear 10 when the vehicle is traveling straight. Are rotated at approximately the same rotational speed. Further, when the vehicle turns, the driving force transmitted to the differential case 5 via the planetary gear 8 is unevenly distributed between the planetary carrier 9 and the sun gear 10 due to the reaction force received by the left and right drive wheels from the road surface. It was comprised so that the outer side drive wheel might rotate more.

  However, in the above-described conventional left / right driving force distribution device for a vehicle, the planetary carrier 9 is positioned in the axial direction by the differential case right member 5A. Further, the planetary carrier 9 is supported by three contact points of the differential case right member 5A, the left member 5B, and the sun gear 10. For this reason, since the differential case 5 and the differential mechanism 13 require higher design accuracy, the cost increases. Furthermore, there is a problem that the difficulty of assembling the differential mechanism 13 in the differential case 5 is high. There is also a problem that the vehicle weight increases due to the large number of parts.

  Further, the bearing 14 that rotatably supports the differential case right member 5 </ b> A is disposed between the opposing surfaces of the differential case right member 5 </ b> A and the housing 2. In addition, the bearing 14 is positioned by the differential case right member 5A. For this reason, the outer diameter of the bearing 14 cannot be increased, and there is a possibility that a high input load cannot be dealt with. Moreover, since it is necessary to use a thinner bearing than a general market distribution product, there also existed a problem of raising cost further.

  Further, when a difference in rotational speed between the left and right drive shafts 11 and 12 occurs, the rotational speed difference becomes the largest in the differential case 5 while sliding relative to each other, so the left and right drive shafts 11 and 12 are seized together. There was a risk of it.

JP 2001-199254 A

  Accordingly, the present invention has been made to solve the above-described problems of the prior art, and is intended to simplify, reduce the weight and reduce the cost of the differential case and the differential mechanism. Easy assembly of the mechanism, the outer diameter of the bearing member that supports the differential case can be increased to handle high input loads, and the drive shafts in the differential case can be greatly burned down to drive left and right It is an object of the present invention to provide a left / right driving force distribution device for a vehicle capable of stabilizing a driving force distribution function to wheels.

In order to achieve the above object, a first invention provides a shaft for transmitting a driving force from a power source, a first driving force transmitting element provided on the shaft, a shaft rotatably supported in a housing, A second driving force transmission element meshing with the first driving force transmission element, a differential case in which the second driving force transmission element is integrated, and a driving force transmitted to the differential case are formed in the differential case. A planetary carrier that rotatably supports a plurality of planetary gears meshed with the internal gear, and a differential mechanism that distributes to the left and right drive wheels by a pair of left and right drive shafts that are connected to different ones of the sun gears meshed with the plurality of planetary gears; In a left and right driving force distribution device for a vehicle equipped with
The first drive shaft connected to one drive wheel is connected to one drive wheel side of the planetary carrier, and the second drive wheel is connected to the hollow second drive shaft into which the first drive shaft is inserted. It is characterized by connecting sun gears.

  To achieve the above object, according to a second invention, in the first invention, the second transmission element is slidably joined to the other drive wheel side of the planetary carrier to position the planetary carrier in the axial direction. And the second transmission element is directly supported by a first bearing member that rotatably supports the differential case.

  To achieve the above object, according to a third invention, in the second invention, the first bearing member is positioned by a spring ring fitted in the second transmission element.

  To achieve the above object, according to a fourth invention, in any one of the first to third inventions, the differential case is in sliding contact with one drive wheel side of the planetary carrier, and the differential case is rotatable. A small-diameter portion supported by the second bearing member to be supported, a large-diameter portion where the internal gear is formed, and the diameter is increased from the large-diameter portion toward the outside in the radial direction, and the second transmission element is fixed. And a flange portion to be provided.

In order to achieve the above object, a fifth invention is characterized in that a differential case integrated with a crown gear that is rotatably supported in a housing and meshes with a drive pinion gear that transmits engine driving force, and a drive that is transmitted to the differential case. The left and right drive is driven by a pair of left and right drive shafts connected to different ones of a planetary carrier that rotatably supports a plurality of planetary gears meshed with an internal gear formed in the differential case and a sun gear meshed with the plurality of planetary gears. A left and right driving force distribution device for a vehicle comprising a differential mechanism for distributing to wheels,
One driving wheel side of the planetary carrier is connected to a first driving shaft connected to one driving wheel, the sun gear is connected to a second driving shaft connected to the other driving wheel, and the other driving of the differential case is connected. The crown gear is fixed to the wheel side, and the crown gear is slidably joined to the other driving wheel side of the planetary carrier to position the planetary carrier in the axial direction, and the differential case can be rotated. The crown gear is directly supported by a supporting first bearing member, and positioning of the first bearing member is performed by a spring ring fitted into the crown gear.

  In order to achieve the above object, according to a sixth invention, in the fifth invention, the differential case is in sliding contact with one drive wheel side of the planetary carrier and is supported by a second bearing member that rotatably supports the differential case. A small-diameter portion to be supported; a large-diameter portion in which the internal gear is formed; and a flange portion that is expanded from the large-diameter portion toward the radially outer side and to which the crown gear is fixed. Features.

  According to the first to sixth inventions, the portion corresponding to the right member of the differential case that has been conventionally positioned in the axial direction of the planetary carrier is reduced from the differential case, and the crown gear integrated with the differential case is the first. In addition to being directly supported by one bearing member, the distance between the housing disposed around the drive shaft and the crown gear is increased as compared with the conventional differential case. The first bearing member is positioned by a spring wheel fitted in the crown gear, and the planetary carrier is positioned in the axial direction by the crown gear. Further, the planetary carrier is supported by two contact points of the small diameter portion of the differential case and the sun gear, and one drive wheel side of the planetary carrier is connected to the first drive shaft, and the sun gear is connected to the second drive shaft. The location where the left and right drive shafts are in sliding contact with each other in the differential case is greatly reduced. As a result, the differential case and the differential mechanism can be simplified, reduced in weight and cost, the differential mechanism can be easily assembled in the differential case, and the bearing outer diameter is increased to increase the load input. To provide a left and right driving force distribution device for a vehicle that can cope with a load, and can reduce the burning of drive shafts in a differential case to stabilize the driving force distribution function to left and right driving wheels. Can do.

  According to the left / right driving force distribution device for a vehicle of the present invention, the portion corresponding to the conventional differential case right member is reduced from the differential case. The planetary carrier is supported by two contact points of the differential case and the sun gear in which a portion corresponding to the conventional differential case right member is reduced. Thereby, simplification, weight reduction, and cost reduction of the differential case and the differential mechanism can be achieved. Moreover, since the outer diameter of the first bearing member is expanded without changing the inner diameter, it is possible to cope with a high load input load. Furthermore, since a product suitable for the first bearing member can be adopted from general market distribution products, the cost can be further reduced. Further, since the portion where the left drive shaft and the right drive shaft are in sliding contact with each other in the differential case is greatly reduced, seizure between the left drive shaft and the right drive shaft in the differential case can be prevented.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a left / right driving force distribution device for a vehicle according to the present embodiment.

  As shown in FIG. 1, the left and right driving force distribution device 100 for a vehicle according to the present invention is rotatably supported in a housing 15 and a crown gear 17 that meshes with a drive pinion gear 16 that transmits engine driving force is integrated. The differential case 18, the rotational gear transmitted to the differential case 18, the planetary gear set 19, that is, the internal gear 20 formed inside the differential case 18, a plurality of planetary gears 21 that mesh with the internal gear 20, and a plurality of planetary gears 21. A planetary carrier 22 that is rotatably supported, a sun gear 23 that meshes with the planetary gear 21, and a pair of left and right drive shafts 24, 25 that are connected to different ones of the planetary carrier 22 or the sun gear 23 to left and right drive wheels (not shown). And a differential mechanism 26 for distribution.

  The housing 15 is a member that forms an outer shell of the left / right driving force distribution device 100. A driving force transmission shaft 27 that transmits engine driving force is rotatably supported by a bearing 28 inside the housing 15. A drive pinion gear 16 is coupled and fixed to the shaft end of the driving force transmission shaft 27.

  Further, inside the housing 15, both end portions of a differential case 18 in which a crown gear 17 meshing with the drive pinion gear 16 is integrated are rotatably supported by bearings 29 and 30 as first and second bearing members. Arranged in a state.

  Further, inside the housing 15, a left drive shaft 24 as a first drive shaft that transmits a drive force distributed by the differential mechanism 26 to the left drive wheel in the drawing, and a right drive wheel in the drawing. In the state where the right drive shaft 25 as the second drive shaft to be transmitted is arranged on the same axis, the right shaft portion of the left drive shaft 24 extends from the left shaft end portion of the right drive shaft 25 in the differential case 18. It is arranged so as to be capable of relative rotation while being inserted inside. A hydraulic motor (not shown) for applying a relative rotational force to the left and right drive shafts 24 and 25 is disposed at the right shaft end of the left drive shaft 24.

  In the differential case 18, a portion corresponding to the differential case right member 5 </ b> A that has been conventionally positioned in the axial direction of the planetary carrier is deleted, and the crown gear 17 integrated with the differential case 18 is directly supported by the bearing 29. For the purpose of enlarging the distance between the housing 15 arranged around the right drive shaft 25 and the crown gear 17 as compared with the conventional differential case, it has a shape different from that of the conventional differential case. That is, the differential case 18 is in sliding contact with the left end portion of the planetary carrier 22 and is supported by a bearing 30 that rotatably supports the differential case 18, a large diameter portion 18B on which the internal gear 20 is formed, and a large diameter portion 18B. The stepped cylindrical member includes a flange portion 18 </ b> C that is formed so as to extend radially outward from the diameter portion 18 </ b> B and to which the crown gear 17 is fixed.

  More specifically, a bearing 30 is disposed between the outer peripheral surface of the small diameter portion 18A and the housing 15, and the left end portion of the planetary carrier 22 is slidably joined to the inner peripheral surface of the small diameter portion 18A. ing. An internal gear 20 is integrally formed along the inner peripheral surface of the large-diameter portion 18B, and a plurality of planetary gears 21 are supported on the planetary carrier 22 so that the left and right shaft end portions are rotatably supported by the planetary carrier 22. Are engaged. The left end portion of the planetary carrier 21 is extended in the drive shaft direction along the inner peripheral surface of the small diameter portion 18A, and the inner peripheral surface of the extended portion is the outer periphery of the left drive shaft 24. In a state of being joined to the surface, they are integrally coupled and fixed by, for example, spline fitting. In addition, the sun gear 23 that meshes with the plurality of planetary gears 21 is integrally coupled and fixed by, for example, spline fitting while being joined to the outer peripheral surface of the left shaft end portion of the right drive shaft 25. As a result, the planetary carrier 22 is supported at two contact points by the small diameter portion 18 </ b> A of the differential case 18 and the sun gear 23.

  A crown gear 17 is fastened and fixed to the flange portion 18C by fixing bolts 31. The crown gear 17 is extended toward the inner peripheral surface side of the right drive shaft 25 and the large diameter portion 18B. An extending portion 17A is formed. The extension 17A is slidably joined to the right side of the planetary carrier 22 so that the planetary carrier 22 is positioned. Further, an annular notch groove 17B is integrally formed on the surface portion of the extended portion 17A facing the right drive shaft 25, and a snap ring 32 as a spring ring fitted into the notch groove 17B. The bearing 29 is positioned.

  The left and right driving force distribution device 100 transmits the rotation of the differential case 18 to the sun gear 23 through the plurality of planetary gears 21 in the same direction. Further, the revolution of the plurality of planetary gears 21 is transmitted to the planetary carrier 22, and the planetary carrier 22 also rotates in the same direction as the differential case 18. When the vehicle is traveling straight, the driving force transmitted to the differential case 18 by the drive pinion gear 16 and the crown gear 17 is evenly distributed to the planetary carrier 22 and the sun gear 23 via the plurality of planetary gears 21, and the left and right sides. The drive shafts 24 and 25 are rotated at substantially the same rotational speed. Further, when the vehicle is turning, the driving force transmitted to the differential case 18 is unevenly distributed to the planetary carrier 22 and the sun gear 23 via the plurality of planetary gears 21 due to the reaction force that the left and right driving wheels receive from the road surface. Then, the drive wheels on the outer side are rotated more than the inner side of the turn. Furthermore, the rotation speed difference between the left and right drive shafts 24 and 25 is absorbed by the rotation of the plurality of planetary gears 21.

  As described above, according to the present invention, the portion corresponding to the differential case right member 5 </ b> A that has been conventionally positioned in the axial direction of the planetary carrier is reduced from the differential case 18, and the crown integrated with the differential case 18 is reduced. The gear 17 is directly supported by the bearing 29, and the distance between the housing 15 disposed around the right drive shaft 25 and the crown gear 17 is increased as compared with the conventional differential case. The bearing 29 is positioned by a snap ring 32 fitted into the crown gear 17, and the planetary carrier 22 is positioned in the axial direction by the crown gear 17. Further, the planetary carrier 22 is supported by two contact points of the small diameter portion 18A of the differential case 18 and the sun gear 23, the left end portion of the planetary carrier 21 is connected to the outer peripheral surface of the left drive shaft 24, and the sun gear 23 is connected to the right drive shaft 25. Since the left and right drive shafts 24 and 25 are slidably contacted with each other in the differential case 18, the position of the left shaft is significantly reduced. As a result, the differential case 18 and the differential mechanism 26 can be simplified, reduced in weight and reduced in cost, the assembly of the differential mechanism 26 in the differential case 18 can be facilitated, and the outer diameter of the bearing 29 can be increased. To cope with a high input load, to greatly reduce the possibility that the left and right drive shafts 24, 25 in the differential case 18 will seize, and to stabilize the drive force distribution function to the left and right drive wheels, etc. Therefore, it is possible to provide a left / right driving force distribution device for a vehicle that can perform the above-described operation.

It is sectional drawing of the left-right driving force distribution apparatus of the vehicle which concerns on this embodiment. It is sectional drawing of the right-and-left driving force distribution apparatus of the conventional vehicle.

Explanation of symbols

15 housing 16 drive pinion gear 17 crown gear 18 differential case 19 planetary gear set 20 internal gear 21 plural planetary gears 22 planetary carrier 23 sun gear 24 left drive shaft (first drive shaft)
25 Right drive shaft (second drive shaft)
26 Differential mechanism 29 Bearing (first bearing member)
30 Bearing (second bearing member)
32 Snap ring (spring ring)
100 Left / right driving force distribution device

Claims (6)

A shaft that transmits driving force from a power source;
A first driving force transmission element provided on the shaft;
A second driving force transmitting element rotatably supported in the housing and meshing with the first driving force transmitting element;
A differential case in which the second driving force transmission element is integrated;
The driving force transmitted to the differential case is
A planetary carrier that rotatably supports a plurality of planetary gears meshed with an internal gear formed in the differential case, and a sun gear that meshes with the plurality of planetary gears, and a pair of left and right drive shafts distributed to the left and right drive wheels. Differential mechanism to
In a left and right driving force distribution device for a vehicle equipped with
The first drive shaft connected to one drive wheel is connected to one drive wheel side of the planetary carrier, and the second drive wheel is connected to the hollow second drive shaft into which the first drive shaft is inserted. A vehicle left-right driving force distribution device characterized by connecting sun gears.   The second transmission element is slidably joined to the other drive wheel side of the planetary carrier to position the planetary carrier in the axial direction, and the first bearing member rotatably supports the differential case. The left and right driving force distribution device for a vehicle according to claim 1, wherein the second transmission element is directly supported.   The left and right driving force distribution device for a vehicle according to claim 2, wherein positioning of the first bearing member is performed by a spring wheel fitted into the second transmission element.   The differential case is in sliding contact with one drive wheel side of the planetary carrier, and is supported by a second bearing member that rotatably supports the differential case, and a large diameter portion on which the internal gear is formed. And a flange portion that expands radially outward from the large-diameter portion and to which the second transmission element is fixed. Vehicle left and right driving force distribution device. A differential case integrated with a crown gear that is rotatably supported in the housing and meshes with a drive pinion gear that transmits engine driving force;
A pair of left and right connected to a planetary carrier that rotatably supports a plurality of planetary gears meshed with an internal gear formed in the differential case, and a sun gear meshed with the plurality of planetary gears. A left and right driving force distribution device for a vehicle comprising: a differential mechanism that distributes to left and right drive wheels by a drive shaft of
One driving wheel side of the planetary carrier is connected to a first driving shaft connected to one driving wheel, the sun gear is connected to a second driving shaft connected to the other driving wheel, and the other driving of the differential case is connected. The crown gear is fixed to the wheel side, and the crown gear is slidably joined to the other driving wheel side of the planetary carrier to position the planetary carrier in the axial direction, and the differential case can be rotated. A left and right driving force distribution device for a vehicle, wherein the crown gear is directly supported by a first bearing member to be supported, and the first bearing member is positioned by a spring wheel fitted in the crown gear.   The differential case is in sliding contact with one drive wheel side of the planetary carrier, and is supported by a second bearing member that rotatably supports the differential case, and a large diameter portion on which the internal gear is formed. The left and right driving force distribution device for a vehicle according to claim 5, further comprising a flange portion that expands radially outward from the large diameter portion and to which the crown gear is fixed.

Images