JPH0828657A - Differential device - Google Patents

Abstract

PURPOSE:To realize the large torque transmission by means of a differential device compact in size by forming a pair of pinion gears and right and left side gears of conical gears having common centers around one point on the axis of rotation of a differential case, and forming the differential case to be conical. CONSTITUTION:One of a pair of pinion gears 3, 5 is formed of a double tooth pinion gear 3 having two teeth 3A, 3B which are axially separated from each other, and the other is formed of a single tooth pinion gear 5. One tooth 3A of the double teeth pinion gear 3 is engaged with one gear 2 of right and left side gears 4, 2, and the other tooth 3B is engaged with the other side gear 4 through the engagement with the single tooth pinion gear 5. In this differential device, a pair of pinion gears 3, 5 and the right and left side gears 4, 2 are formed of conical gears having a common center around one point on the axis of rotation, and a differential case 1 to store these conical gears is also formed conical.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential device for transmitting a rotational driving force of a differential case through a planetary gear in the differential case to the left and right side gears arranged on the rotary shaft of the differential case by distributing torque. It is about.

[0002]

2. Description of the Related Art As a differential device including a planetary gear of this type, there is a conventional differential device shown in FIG.
There is a differential limiting device as described in Japanese Patent Laid-Open No. 107345. In the first conventional example, when the drive input from the differential case 21 is transmitted to the left and right pressure rings 29 and 30 which are spline-fitted to the differential case, as shown in FIG.
As enlargedly shown in (B), these pressure rings 29 and 30 are cams of the pinion shaft 28 that constitutes a differential device via cam surfaces 29A and 30A of a predetermined angle provided on the facing surfaces thereof. When the surface is driven by a predetermined driving force, it is axially moved by the cam surface of the pinion shaft 28 to be expanded and a thrust force is obtained. As a result, during normal straight running, particularly during acceleration, the thrust rings generated by receiving a predetermined driving force move the pressure rings 29, 30 axially outward to connect the left and right multi-plate clutches 31, 32. However, since the outer clutch plate that rotates with the differential case 21 and the inner clutch plate that rotates with the left side gear 24 and the right side gear 22, respectively, are connected to each other, the above-mentioned members can be integrated into one another to reliably provide a driving force. I can tell. Further, when the vehicle encounters a bad road such as a mud and tries to generate an excessive differential action due to one wheel slipping, torque corresponding to the road surface resistance of the wheel is transmitted to the high speed wheel side. However, because the pressure ring drives the pinion shaft, the multi-plate clutch on the high-speed wheel side is engaged and braking occurs,
Since excessive differential action can be suppressed and the distributed torque can be increased on the low-speed wheel side to increase, it is possible to escape from a rough road. However, in this type, the pinion gear 23, which constitutes a planetary gear as a differential device, is arranged orthogonal to the rotation axis of the differential case 21,
Moreover, due to the presence of the multi-plate clutch and the like, the dimension in the radial direction from the rotary shaft increases, and when a differential device is installed in a front-wheel drive type vehicle, a bell housing of a transmission or the like as shown by a chain line is shown. In many cases, the space adjacent to B must be adapted, and therefore, there is a possibility that the power transmission performance may be adversely affected due to restrictions such as a reduction in radial dimension.

Therefore, as a differential device which can be incorporated in a space subject to such restrictions and which is compact in the radial direction and has good power transmission performance, as shown in FIG. What was described in 60-175843 was devised. In the second conventional example, the rotational driving force of the differential case 21 transmitted from the propulsion shaft via the ring gear 27 is housed in the differential case 21 in parallel with the rotational axis of the differential case. 3B is a differential device that distributes and transmits torque to the left and right side gears 24, 22 and the left and right output shafts 33, 34 arranged on the rotating shaft of the differential case 21 through a plurality of sets of As shown in the schematic view, the pair of helical pinion gears 23 and 25 mesh with each other at an overlapping meshing portion D of the intermediate portion, one helical pinion gear 23 meshes only with the left side gear 24, and the other helical pinion gear 25 It is a differential device of the type that meshes only with the side gear 22. With the above configuration, when there is no difference in road surface resistance between the left and right wheels, the pair of helical pinion gears 23 and 25 and the side gear rotate integrally without any relative rotation, and the rotational driving force from the differential case is generated. Distribute to the left and right evenly. Further, when a difference in road surface resistance occurs between the left and right wheels, the pinion gears 23 and 25, which are helical gears, and the side gear 2 are formed.
When the gears 2 and 24 are meshed with each other, a thrust force is applied in the axial direction, and the differential limiting torque is generated by the sliding of these gears and the differential case or the sliding contact between the gears. Is given a driving force. As a result, a differential gear which is compact in the radial direction and has good power transmission performance can be provided.

[0004]

However, even in the case of the second conventional example, in order to increase the transmission torque, the axial length of the meshing portion is increased or each gear itself is increased. As a result, similarly to the first conventional example, the side surface of the differential case 21 may interfere with the bell housing B shown by the chain line in FIG. For this reason, the present invention solves various problems in the above-mentioned conventional differential gear composed of the planetary gears, and is capable of large torque transmission while being compact in the radial direction and the axial direction, and is excellent in power transmission performance. Also provides an easy differential.

[0005]

Therefore, in the present invention, as a means for solving the above-mentioned conventional problems, a plurality of sets of a pair of pinion gears axially supporting or accommodating the rotational driving force of the differential case in the differential case. And a pair of pinion gears, one of which is a multi-toothed pinion gear having two teeth axially separated from each other. The other is constituted by a single-toothed pinion gear, one tooth of the multi-toothed pinion gear meshes with one of the left and right side gears, and the other tooth of the left and right toothed gears meshes with the single-toothed pinion gear. In the differential gear of the type that meshes with the other of the side gears, the pair of pinion gears and the left and right side gears are on the rotation axis of the differential case. In order to solve the problem, it is characterized in that it is configured by a conical gear having a common center at almost one point, and the differential case is also formed in a conical shape to properly accommodate these conical gears. Is the means of. Further, the present invention is characterized in that, of the meshing portions of the pair of pinion gears and the left and right side gears, the closer to the common center of these conical gears, the larger the axial length of the meshing portions.

[0006]

According to the present invention, the pair of pinion gears and the left and right side gears are constituted by conical gears having a common center at substantially one point on the rotation axis of the differential case, and the differential case also properly accommodates these conical gears. Since it is formed in a conical shape, it does not interfere with the bell housing when it is mounted on a front-wheel drive vehicle, and the space of the differential case can be effectively utilized to the maximum extent. Moreover, as a result of the pinion gears being arranged to be inclined, the size in the direction of the differential case rotation axis can be shortened even though the pinion gear is a large pinion gear long in the axial direction, so the axial length of the meshing part with the side gears is also reduced. Can be big,
Greater torque transmission is possible, and the degree of freedom in selecting the magnitude of the transmission torque is increased. As a result, among the meshing portions of the pair of pinion gears and the left and right side gears, the one closer to the common center of these conical gears,
By increasing the axial length of the meshing portion, that is, the gear is closer to the common center of the conical gears, the radius is smaller, but by increasing the axial length of the meshing portion at the smaller radius, It became possible to equalize the bending stress of each gear. Moreover, the differential case is also conically shaped to properly accommodate these conical gears,
When the differential case is manufactured by forging, it is extremely easy to remove it from the mold. The pinion gear and the side gear may be straight conical gears, and these are easy to manufacture by forging. Further, in the case of a helical conical gear, it is effective as a means for generating a thrust force in the axial direction.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the differential limiting device of the present invention. FIG. 1A is a sectional view of the whole, and FIG.
FIG. 3 is a schematic view showing a center common to each conical gear. The rotational driving force of the differential case 1 transmitted from the propulsion shaft through the ring gear 6 (two-dot chain line) is passed through a plurality of pairs of pinion gears 3 and 5 housed in the differential case 1 and on the rotary shaft of the differential case 1. Is a differential device that distributes and transmits torque to the left and right side gears 4 and 2 arranged at. Differential case 1
Is composed of a left differential case 1B fixed to the ring gear 6 and a right differential case 1A mainly containing the pinion gears 3 and 5. One of the pair of pinion gears is constituted by a multi-toothed pinion gear 3 having two teeth 3A and 3B separated in the axial direction and the other is constituted by a single-toothed pinion gear 5, and one tooth 3 of the multi-toothed pinion gear 3 is formed.
A is meshed with one of the left and right side gears 4, 2 (right side gear 2), and the other tooth 3B is meshed with the tooth 5A of the single-toothed pinion gear 5 so that one of the left and right side gears 4, 2 is Of the differential gear of the type which meshes with the other (left side gear 4). In the present invention, as shown in FIG. 1 (B), the pair of pinion gears 3, 5 and the left and right side gears 4, 2 are conical gears having a common center O at almost one point on the rotation axis L of the differential case 1. In addition, the right differential case 1A for accommodating the pair of pinion gears 3, 5 of the differential case 1 is also formed in a conical shape so as to properly accommodate these conical gears. In FIG. 1, the multi-toothed pinion gear 3
The single-toothed pinion gear 5 and the single-toothed pinion gear 5 are depicted separately in the upper and lower parts of the drawing, but a plurality of pairs are arranged in pairs on the outer circumferences of the side gears 2 and 4 and always meshed with each other (mesh length L in the axial direction).
3). In the present invention, the pair of pinion gears 3 and 5 and the left and right side gears 4 and 2 are thus constituted by conical gears having a common center O at almost one point on the rotation axis L of the differential case 1, and the differential case 1 Also, since these conical gears are formed into a conical shape so as to be properly accommodated, they do not interfere with the bell housing B when mounted on a front-wheel drive vehicle, and the space of the differential case 1 can be effectively utilized to the maximum extent. It was Moreover, as a result of the pinion gears 3 and 5 being inclined, the size of the pinion gear in the axial direction of the differential case can be shortened even though the pinion gear is a large pinion gear that has a long dimension in the axial direction. The axial length of the portion can be increased, which enables large torque transmission and also increases the degree of freedom in selecting the magnitude of the transmission torque.

In the present invention, among the meshing portions of the pair of pinion gears 3 and 5 and the left and right side gears 4 and 2,
The closer to the common center O of these conical gears, the larger the axial length of the meshing portion. Referring to FIG. 1 (A), from the side closer to the common center O of conical gears,
To show the meshing portion of the gears, the teeth 3 of the multi-toothed pinion gear 3 are shown.
A and the tooth 2A of the right side gear 2 mesh (axial mesh length L1), the tooth 4A of the left side gear 4 and the tooth 5A of the single-tooth pinion gear 5 (axial mesh length L2), multiple teeth The teeth 3B of the pinion gear 3 and the teeth 5A of the single-toothed pinion gear 5 are in the meshing order (the meshing length L3 in the axial direction). here,
The mesh length is selected so that L1>L2> L3. With this structure, the gears closer to the common center O have a smaller radius, and the axial length of the meshing portion of the conical gear having a smaller radius is increased to equalize the bending stress of each gear. It will be possible. Further, the further the gear is from the common center O, the larger its radius is. Therefore, the tooth profile, that is, the tooth thickness in the meshing portion at that portion can be designed large, and the transmission torque is large even if the meshing length is not so large. Moreover, the differential case is also conically shaped to properly accommodate these conical gears,
When the differential case is manufactured by forging, it is extremely easy to remove it from the mold. The pinion gear and the side gear may be straight conical gears, and these are easy to manufacture by forging.

Although the embodiment of the present invention has been described above, not only the pinion gear having two teeth separated in the axial direction like the multi-toothed pinion gear of this embodiment, but also the single-toothed pinion gear as shown in FIG. It can also be adopted in a differential device in which a pair of pinion gears by meshing with each other and left and right side gears are combined. Also, within the scope of the present invention,
The shape of the differential case, the shape of the pinion gear and the side gear, the shape related to meshing between them, and the like can be appropriately selected. Further, it is best to form the teeth of the pinion gears and side gears into straight conical gears to facilitate manufacturing by forging.For example, by forming a helical mesh that appropriately combines the inclination directions, the left and right wheels can be connected. It is also possible to generate a larger thrust force at the time of differential with a difference in road surface resistance, and to generate a differential limiting force by combination with an appropriate multi-plate clutch or sliding with a differential case.

[0010]

As described in detail above, according to the present invention, the rotational driving force of the differential case is arranged on the rotary shaft of the differential case through a plurality of pairs of pinion gears that are pivotally supported or housed in the differential case. And a pair of pinion gears, one of which is a multi-toothed pinion gear having two teeth separated in the axial direction and the other of which is a single-toothed pinion gear. And one tooth of the multi-toothed pinion gear meshes with one of the left and right side gears, and the other tooth meshes with the other of the left and right side gears through meshing with the single-toothed pinion gear. In the differential device, the pair of pinion gears and the left and right side gears are conical gears having a common center at almost one point on the rotation axis of the differential case. In addition to being configured, the differential case also has a conical shape to properly accommodate these conical gears, so it does not interfere with the bell housing when mounted on a front-wheel drive vehicle, maximizing the space of the differential case. Can be effectively used. Moreover, as a result of the pinion gears being arranged to be inclined, the size in the direction of the differential case rotation axis can be shortened even though the pinion gear is a large pinion gear long in the axial direction, so the axial length of the meshing part with the side gears is also reduced. In addition to being able to increase the transmission torque, the transmission of a large amount of torque is possible, and the degree of freedom in selecting the amount of transmission torque is increased. Further, among the meshing portions of the pair of pinion gears and the left and right side gears, the closer to the common center of these conical gears, the closer to the common center of the conical gears by increasing the axial length of the meshing portion. The smaller the radius, the larger the axial length of the meshing portion at the smaller radius,
It became possible to equalize the bending stress of each gear. Moreover, since the differential case is also formed in a conical shape so as to properly accommodate these conical gears, when the differential case is manufactured by forging, it is extremely easy to remove it from the mold. Further, the pinion gear and the side gear may be straight conical gears, and these can be easily manufactured by forging.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a differential device of the present invention.

FIG. 2 is a diagram showing a first conventional example of a differential device.

FIG. 3 is a diagram showing a second conventional example of a differential device.

[Explanation of symbols]

 1 differential case 2 right side gear 3 compound tooth pinion gear 4 left side gear 5 single tooth pinion gear B bell housing O common center of conical gear

Claims (2)

[Claims] 1. A rotational driving force of a differential case is distributed through a plurality of pairs of pinion gears axially supported or housed in the differential case to the left and right side gears arranged on the rotary shaft of the differential case and transmitted. In the differential device, one of the pair of pinion gears is configured by a multi-toothed pinion gear having two teeth separated in the axial direction, and the other is configured by a single-toothed pinion gear, and one tooth of the multi-toothed pinion gear is In a differential gear of the type that meshes with one of the left and right side gears and the other tooth meshes with the other of the left and right side gears through meshing with the single-toothed pinion gear, the pair of pinion gears and the left and right The side gear is composed of a conical gear having a common center at almost one point on the rotation axis of the differential case, and the differential case is also A differential limiting device having a conical shape for properly housing these conical gears. 2. The axial length of the meshing portion is increased as the meshing portion of the pair of pinion gears and the left and right side gears is closer to the common center of the conical gears. The limited differential device described.