JPH0633996A - Differential gear - Google Patents

Abstract

(57) [Abstract] [Purpose] Equipped with a torque sensitive type differential differential speed sensitive type differential limiting means and a uniform differential between one side differential gear idling and the other side differential gear idling. An object of the present invention is to provide a differential device that can obtain limiting characteristics. [Configuration] The differential device (7) of the present invention comprises:
A pair of differential gears (3
7, 39), a connecting gear (63) that connects the differential gears (37, 39) so as to be differentially rotatable, and each of these gears (3
7, 39, 63) rotatably supporting the differential case (2
1) and a differential gear mechanism (75) and a drive force sent to one or the other power transmission shaft when one or the other power transmission shaft idles while the differential case (21) is rotationally driven. And a speed sensitive differential limiting means (111) sensitive to the differential rotation speed between the differential gears (37, 39). .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential device used in a vehicle.

[0002]

2. Description of the Related Art Differential devices 201 and 203 as shown in FIGS. 7 and 8 are described in Japanese Utility Model Publication No. 63-78746 and Japanese Utility Model Publication No. 62-172842, respectively.

The differential devices 201 and 203 are bevel gear type differential gear mechanisms 207 and 209, differential limiting viscous couplings 211 and 213, and a multi-plate clutch 215.
217 and 217, respectively. The viscous couplings 211 and 213 are speed-sensitive type differential limiting means that generate a larger differential limiting force as the differential rotation speed increases. or,
The multi-plate clutches 215 and 217 are side gears 21 respectively.
The multi-plate clutches 215 and 217 are of the torque sensitive type because the engagement reaction force of the gears 9, 221 against the pinion gears 223, 225 is fastened, and the engagement reaction force becomes stronger as the transmission torque of the differential gear mechanism 207, 209 increases. It is a differential limiting means.

[0004]

As shown in FIG. 6, in the differential device 201, the left side gear 219 in the figure is connected to the left axle 233 via the hub 231 and the right side gear 23 is connected.
5 is connected to the right axle 237. Multi-plate clutch 2
Reference numeral 15 is an SH type (S: shaft, H: housing) arranged between the hub 231 and the differential case 239 (housing). Further, as shown in FIG. 7, in the differential device 203, the multi-plate clutch 217 is disposed between the right side gear 221 and the differential case 241 in the figure, and the viscous coupling 213 is disposed between the left side gear 243 and the differential case 241. They are arranged, and all are S-H type.

In the differential device 201, the multi-plate clutch 2
The transfer ratios (R _t ) of the left and right axles 233, 237 caused by 15 are set to R _tL and R _tR , respectively.

[0006]

[Equation 1] f _L : Friction torque generated in the multi-plate clutch 215 according to the input torque and transmitted to the left axle 233 side.

F _R : Multi-plate clutch 2 according to the input torque
Friction torque generated in 15 and transmitted to the right axle 237 side.

Since f _L = 0 here

[Equation 2] Therefore, R _tL ≠ R _{tR and} one-sided effect occurs.

In this case, in FIG. 7, the left and right axles 233,
The driving force indicated by a thick arrow 249 is input to 237, and the driving force indicated by a broken arrow 251 is applied to the right axle 237 to strengthen the right axle 237.

As described above, when the differential limiting means is arranged in the S-H type, the differential limiting forces become non-uniform on the left and right, and a one-sided effect occurs.

FIG. 9 is a graph showing the differential limiting characteristic of the differential device 201, in which the vertical axis represents the axial torque sent to the right wheel when the left wheel idles, and the horizontal axis sends the left wheel when the right wheel idles. It is the shaft torque. Graphs 253 and 255 are the right shaft torque and the left shaft torque by the multi-plate clutch 215, respectively, and are asymmetric with respect to the straight line 257 of 45 °, and show that the right shaft torque is larger than the left shaft torque as described above. ing. The gradient of the graph 253 with respect to the horizontal axis and the gradient of the graph 255 with respect to the vertical axis are referred to as a transfer ratio (R _t ).

Therefore, the characteristics of the differential device 201 as a whole are graphs 259 and 261 in which the differential limiting force by the viscous coupling 211 is evenly applied to the graphs 253 and 255.

FIG. 10 is a graph showing a differential limiting characteristic of the differential device 203, and graphs 263 and 265 are characteristics of the multi-plate clutch 217. Since the multi-plate clutch 217 is arranged in the SH type on the right side gear 221 side, the left shaft torque is larger than the right shaft torque. Therefore, the differential device 203
The overall characteristics are graphs 267 and 269 in which the differential limiting force of the viscous coupling 213 is added to the graphs 263 and 265.
And is asymmetric with respect to the straight line 257.

As described above, conventionally, there has not been a differential device having a torque-sensitive type characteristic and a speed-sensitive type characteristic and having a uniform differential limiting characteristic on one side and the other side.

In view of this, the present invention is provided with the torque-sensitive type speed limiting type differential speed limiting type differential limiting means, and has a uniform differential limiting characteristic when one side differential gear idles and the other side differential gear idles. It is intended to provide a differential device that can obtain

[0016]

SUMMARY OF THE INVENTION A differential device according to the present invention comprises a pair of differential gears connected to respective power transmission shafts, a connecting gear connecting these differential gears so as to be differentially rotatable, and these. A differential gear mechanism having a differential case rotatably supporting the respective gears, and when one or the other power transmission shaft idles while the differential case is rotationally driven, the differential gear mechanism is sent to the other or one power transmission shaft, respectively. A torque sensitive differential limiting means having equal driving forces, and a speed sensitive differential limiting means interposed between the power transmission shafts and sensitive to a differential rotation speed between the differential gears. Is characterized by.

[0017]

The driving force input from the differential case to the differential gear mechanism is distributed to each power transmission shaft via the connecting gear and the differential gear. Further, the differential gear differentially rotates according to the drive resistance difference on each power transmission shaft side, and the driving force is differentially distributed to each power transmission shaft side.

A speed-sensitive differential limiting means is arranged in the SS type with respect to this differential gear mechanism, and the torque-sensitive differential limiting means is different even if any of the power transmission shafts idles. The driving forces sent to the ground-side power transmission shaft are equal to each other, and uniform differential limiting characteristics are obtained on one side and the other side. Since the speed-sensitive differential limiting force is evenly applied to this characteristic, the entire differential limiting characteristic is uniform on one side and the other side, and no one-sided effect that deteriorates maneuverability does not occur.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described with reference to FIGS. FIG. 1 shows the differential device of this embodiment,
FIG. 4 shows a power system of a vehicle using this differential device. Further, the left and right directions are the left and right directions in this vehicle and FIG. 1, and members and the like without reference numerals are not shown.

As shown in FIG. 4, this power system includes an engine 1,
The transmission 3, the propeller shaft 5, the rear differential 7 (the differential device of FIG. 1 arranged on the rear wheel side), the rear axles 9, 11, the left and right rear wheels 13, 15, the left and right front wheels 17, 19 and the like. . In the rear differential 7, the differential case 21 is rotatably arranged in the differential carrier 23, and the ring gear 25 fixed to the differential case 21 meshes with the drive pinion gear 27. The drive pinion gear 27 is formed integrally with a drive pinion shaft 29 connected to the propeller shaft 5 side. In this way, the driving force of the engine 1 is transmitted to the rear differential 7 via the transmission 3 and the propeller shaft 5 to rotationally drive the differential case 21.

As shown in FIG. 1, the differential case 21 has a main body 31.
And a cover 35 fixed to the main body 31 with screws 33, and a pair of side gears 37 and 39 (differential gears) are arranged inside. The left hub 41 is arranged on the left side of the side gear 37, and the flange portion 43, the cylindrical member 45, the right flange 47, and the left side gear 37 are integrally formed by welding. Hub 41 is cover 3
5 is rotatably supported by a shaft support portion 49, and a washer 51 is arranged between the flange portion 43 and the cover 35. The right side gear 39 is formed on the right hub 53, and this hub 53 is attached to the shaft support portion 55 of the main body 31.
It is rotatably supported by. The left rear axle 9 is spline-connected to the left hub 41 and is prevented from falling off by a retaining ring 57. The right hub 53 is spline-connected to the right rear axle 11 and is prevented from falling off by a retaining ring 59. There is.

The main body 31 is provided with a long storage hole 61 and a short storage hole circumferentially adjacent to the storage hole 61 in the axial direction. A pinion gear 63 (connecting gear) is slidably rotatably housed in the housing hole 61, and a short pinion gear (connecting gear) is slidably rotatably housed in the short housing hole.

The long pinion gear 63 has the left and right gear parts 6
5, 67 and a shaft portion 69 connecting them, and the shaft portion 69 has a small diameter to avoid interference with the right side gear 39. The left gear portion 65 meshes with the left side gear 37, and the right gear portion 67 meshes with the right end portion of the short pinion gear. The short pinion gear meshes with the right side gear 39 at the left end. A thrust washer 71 and retaining rings 73, 73 are attached to the body 31 to prevent the long and short pinion gears from falling off. In this way, the differential gear mechanism 75 is configured.

The driving force of the engine 1 for rotating the differential case 21 is distributed from the respective pinion gears to the side gears 37, 39, and the left and right rear wheels 13, 15 via the rear axles 9, 11.
Be transmitted to. When a driving resistance difference occurs between the rear wheels, the driving force of the engine 1 is differentially distributed to the left and right sides by the rotation of each pinion gear.

Each gear of the differential gear mechanism 75 is a helical gear. When the differential case 21 is rotationally driven when the vehicle is moving forward, the side gears 37, 39 are pushed and slid by the sliding portions 81 between them due to the thrust forces 77, 79 generated by the meshing with the pinion gears. When the differential case 21 is rotationally driven in the reverse direction of the vehicle, the flange portion 43 is caused to move by the washer 51 due to the mesh thrust force 83 of the side gear 37.
And the side gear 39 slides at the sliding portion 89 with the main body 31 by the meshing thrust force 87.
The friction coefficient of the sliding portion 81 is set to be larger than the friction coefficients of the sliding portions 85 and 89.

The long end of the long pinion gear 63 slides on the flange 47 and the right end slides on the thrust washer 71 due to the meshing thrust force. The left end of the short pinion gear slides on the main body 31, and the right end slides on the thrust washer 71. These sliding parts have the same friction coefficient.
Further, a rotational friction resistance can be obtained between each pinion gear and its housing hole.

The rotation of each pinion gear and the side gears 37, 39 is braked by the frictional resistance of each pinion gear and the frictional resistance of each sliding portion due to the meshing thrust force, and the differential rotation of the differential gear mechanism 75 is restricted. Since this frictional resistance changes in proportion to the transmission torque of the differential gear mechanism 75, each sliding portion constitutes a torque sensitive differential limiting means.

A hub 91 is arranged between the flange portion 43 and the flange 47 on the left side gear 37 side.
It is rotatably supported on the outer circumference of. The hub 91 is provided with a connecting portion 95 penetrating rightward through the gap 93 between the left side gear 37 and the hub 41, and the connecting portion 95 is spline-connected to the right hub 53. Flange part 43
A working chamber 97 is formed between the cylindrical member 45, the flange 47, and the hub 91. The working chamber 97 is filled with high-viscosity silicon oil from a filling hole 99 and sealed by a ball 101 caulked in the filling hole 99. Has been done. Cylindrical member 45
A large number of outer plates engage with the hub 91, and inner plates arranged alternately with the outer plates engage with the hub 91. An X ring 103 (a seal having an X-shaped cross section) and a backup ring 105 are arranged between the hub 91 and the hub 41, and an X ring 107 and a backup ring 109 are provided between the side gear 37 and the connecting portion 95. Is placed to prevent the leakage of silicone oil.

Thus, the viscous coupling 111
(Velocity sensitive differential limiting means). Since the outer plate is connected to the left rear axle 9 via the hub 41, and the inner plate is connected to the right rear axle 11 via the hub 91 and the hub 53, the viscous coupling 111 is the SS type. The arrangement limits the differential rotation of the differential gear mechanism 75.

Since the hub 91 of the viscous coupling 111 is connected to the hub 53 by the connecting portion 95, as shown in FIG.
In contrast with the conventional example in which the right axle 237 has to be longer than the left axle 233 in order to connect with the viscous coupling 211, the left and right rear axles 9, 11 are different from each other.
Can be of equal length.

In this way, the rear differential 7 is constructed.

Next, the differential limiting characteristic of the rear differential 7 will be described with reference to FIGS.

FIG. 2 is a graph showing the transfer ratio (R _t ) of the rear differential gear 7, where the first quadrant is the forward drive side region and the third quadrant is the reverse drive side (coasting side) region. The upper side of the 45 ° straight line 113 in the first and third quadrants is the region of the axial torque sent to the right rear wheel 15 via the rear differential 7 when the left rear wheel 13 idles, and the lower side is the right rear wheel 15 Is a region of the axial torque sent to the left rear wheel 13 when the wheel slips.

Graphs 115, 117, 119 and 121 are transfer ratios of the torque sensitive type differential limiting means, and graphs 123, 125, 127 and 12 obtained by adding the differential limiting force of the viscous coupling 111 to these graphs.
9 is the differential limiting characteristic of the entire rear differential 7.

The frictional resistance between the pinion gear of the torque-sensitive differential limiting means and the housing hole is equal to that when the left side gear 37 rotates in advance and when the right side gear 39 rotates in advance, and each pinion gear due to the mesh thrust force. The sliding frictional resistances at the ends are equal to each other as described above.
Therefore, the differential limiting means has no one-sided effect in both forward and backward movements, and graphs 115 and 117 and graphs 119 and 121 are symmetrical with respect to the straight line 113. Further, as described above, since the sliding resistance of the sliding portion 81 is made larger than the sliding resistance of the sliding portions 85 and 89, the R _t of the graphs 115 and 117 when moving forward is larger than the R _t when moving backward. . Further, since the viscous coupling 111 is arranged in the S-S type, the differential limiting force of each of the graphs 115, 1 is
Graphs 123, 125 added to 17, 119, 121,
127 and 129 are also symmetrical with respect to the straight line 113, and the rear differential 7 does not have a one-sided effect.

In the vehicle of FIG. 4, even when the left rear wheel 13 idles and the left axle torque decreases to T _L1 when driving on a bad road, for example, a large axle torque T _R1 is sent to the right rear wheel 15 to cause an adverse effect. Road running performance is greatly improved. At this time, since there is no one-sided effect, the driving force sent to the rear wheel on the grounding side is equalized regardless of whether the idling side is on the left or right, and the maneuverability and safety are greatly improved.
In addition, obtaining such a large differential limiting force makes the stability of the vehicle body particularly high at high torque, and is suitable for sporty traveling.

Further, as shown in FIG. 2, the graphs 123, 12 are
The gradients of 5, 127, 129 are the graphs 115, 117, 1
It depends on the slope of 19,121. Therefore, the effect of the differential limiting force of the viscous coupling 111 is also shown in graph 11.
5, 117, 119, and 121, the difference between these effects is the initial torque T _iD at the time of forward movement, which is the contact piece between the graph 123 and the vertical axis, and the backward torque, which is the contact point between the graph 129 and the vertical axis. It appears as a difference from the initial torque T _ic .
Here, the gradients of the graphs 123 and 129 are respectively set to R _tD ,
If R _tc and the unit torque of the viscous coupling 111 are T _Vc , then T _iD = T _Vc (R _tD +1) T _ic = T _Vc (R _tc +1) and R _tD > R _{tc. iD} > T _ic .

As described above, by combining with the torque sensitive type differential limiting means in which R _t is changed in forward and backward movement, the entire characteristic including the characteristic of the viscous coupling 111 can be changed in forward and backward movement.

FIG. 3 is a graph showing the differential limiting force with respect to the input torque of the rear differential 7. The graph 131 is improved because the differential limiting force at the time of forward movement is large due to the large R _t of the graphs 123 and 125 of FIG. 2, and the graph 133 is at the differential limiting force at the time of reverse traveling and during engine braking.
It is shown that R _{t of} 9 is reduced by being small. Further, a broken line 135 indicates the limit torque of ABS (anti-lock brake system), and if the maximum input torque during engine braking is T ₁ , the differential limit torque T _{2 at} that time will not exceed the limit torque of ABS. , ABS
Interference with can be avoided.

As described above, the rear differential 7 has the speed-sensitive viscous coupling 111 in addition to the torque-sensitive differential limiting means in which the left and right transfer ratios are equal to each other. Also, the differential control characteristics between left and right will be improved, and the maneuverability of the vehicle will be greatly improved.
Further, by adopting this structure, it becomes easy to make the transfer ratio of the torque sensitive differential limiting means large when the vehicle moves forward and small when the vehicle moves backward, and when the differential limiting force of the viscous coupling 111 remains symmetrical. However, a large differential limiting force can be obtained when moving forward, and interference with the ABS of the vehicle can be prevented during engine braking. or,
In addition to this, the rear axles 9 and 11 can be made equal in length.

Next, the second embodiment will be described with reference to FIG. In this embodiment, the meshing portion between the pinion gears on the rear differential 7 of the first embodiment is on the right end side of the differential gear mechanism 75, while this meshing portion is on the left end side of the differential gear mechanism. To do. Only the differences from the rear differential 7 will be described below. 5, members having the same functions as those in FIG. 1 are designated by the same reference numerals as those in FIG. The differential device of this embodiment is similar to the rear differential gear 7 of the first embodiment shown in FIG.
Used as the rear differential 137 of the vehicle.

The left and right side gears 1 are provided in the differential case 21.
39, 141 (differential gears) are arranged, the left side gear 139 is formed on the left hub 143, and the right side gear 141 is formed on the right hub 145. The hubs 143, 145 support each other at their free ends by a shaft support portion 147, and a washer 149 is arranged between the right hub 145 and the main body 31. Hub 41 has left rear axle 9
Is spline-connected, and the right rear axle 11 is spline-connected to the hub 145.

A housing hole 15 provided in the main body 31 in the axial direction.
1, a long pinion gear 153 (connecting gear) is slidably rotatably housed, and a short pinion gear (connecting gear) is slidably rotatably installed in an axial storage hole adjacent to the storage hole 151 in the circumferential direction. It is stored in.

The long pinion gear 153 is the left and right gear unit 1
55, 157 and a shaft portion 159 connecting them,
The left gear portion 155 meshes with the left end portion of the short pinion gear, and the right gear portion 157 meshes with the right side gear 141. The right end of the short pinion gear meshes with the left side gear 139. Each of these gears is a helical gear. In this way, the differential gear mechanism 161 is configured.

When the differential case 21 is rotationally driven in the rotational direction when the vehicle is moving forward, the side gears 139 and 141 slide on their mutual sliding portions 163 due to the mesh thrust force with each pinion gear. When the differential case 21 is rotationally driven in the reverse direction, the flange portion 43 slides on the sliding portion 165 with the washer 51 due to the meshing thrust force in the opposite direction, and the hub 145 slides on the sliding portion 167 with the washer 149. Slide on. The friction coefficient of the sliding portion 163 is determined by the sliding portions 165, 16
Therefore, the frictional resistance when moving forward is larger than that when moving backward. The left end of each pinion gear slides on the hub 143 due to the thrust force of the meshing part, and the right end of the pinion gear is connected to the main body 3.
1 and thrust washer 71. The friction coefficients of these sliding parts are made equal. A torque sensitive differential limiting means for the differential gear mechanism 161 is configured by each sliding portion. Also, the viscous coupling 111 is the hub 4
1 and the hub 145 are arranged in the SS type.

Therefore, the rear differential 137 does not have a left-right one-sided effect of the differential limiting force during forward and backward movements, and a large differential limiting force is obtained during forward traveling, and the differential limiting force is reduced during reverse traveling (during coasting). As a result, it gives the vehicle excellent maneuverability and sporty driving performance.
The interference with S can be avoided.

Further, the third embodiment will be described with reference to FIG.

In this embodiment, the plunger pump type coupling 169 is arranged with respect to the viscous coupling 111 as the speed-sensitive type differential limiting means in the rear differential gear 7 of the first embodiment. The coupling 169 and the differential gear mechanism 171 for forming the torque-sensitive differential limiting means include the left and right rear axles 9,
11 between the left and right hubs 173 and 175 which are in contact with SS
It is arranged in a mold. This embodiment also has the same effects as the first and second embodiments.

[0049]

According to the differential device of the present invention, the differential limiting characteristic is obtained when the power transmission shaft on the differential gear side on one side of the differential gear mechanism is idling and the power transmission shaft on the differential gear side on the other side is idling. In addition to the uniform torque sensitive differential limiting means, the speed sensitive differential limiting means is arranged between the power transmission shafts, so that a uniform differential limiting characteristic is obtained on one side and the other side. Also, the differential limiting force of the torque sensitive differential limiting means can be easily changed in the direction of differential rotation.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a graph showing the differential limiting characteristic of the first embodiment.

FIG. 3 is a graph showing a differential limiting characteristic of the first embodiment.

FIG. 4 is a skeleton configuration diagram showing a power system of a vehicle using each embodiment.

FIG. 5 is a sectional view of a second embodiment.

FIG. 6 is a sectional view of a third embodiment.

FIG. 7 is a cross-sectional view of a first conventional example.

FIG. 8 is a sectional view of a second conventional example.

FIG. 9 is a graph showing a differential limiting characteristic of the first conventional example.

FIG. 10 is a graph showing a differential limiting characteristic of a second conventional example.

[Explanation of symbols]

7,137 Rear differential (differential device) 9 Left rear axle (power transmission shaft) 11 Right rear axle (power transmission shaft) 21 Differential case 37,39,139,141 Side gear (differential gear) 63,153 Pinion gear (coupling gear) 75 , 161, 171 Differential gear mechanism 111 Viscous coupling (speed-sensitive differential limiting means) 169 Plunger pump type coupling (speed-sensitive differential limiting means)

Claims (1)

[Claims] 1. A pair of differential gears connected to respective power transmission shafts, a connecting gear for connecting these differential gears to allow differential rotation, and a differential case for rotatably supporting each of these gears. And a torque-sensitive differential mechanism in which the driving forces sent to the other or one power transmission shaft when the one or the other power transmission shaft idles while the differential case is rotationally driven are equal to each other. Limiting means,
A differential device, comprising: a speed-sensitive differential limiting means that is interposed between the two power transmission shafts and that senses a differential rotation speed between differential gears.