JPH09257115A - Differential gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strengthen the drive force transmission passage inside a differential case rotated and driven by a drive shaft penetrated in a center through a torque input part and transmit a big torque. SOLUTION: This device is provided with output side gears 41, 43 arranged in both side of the axial direction of the torque input part 69 of a differential case 31, at least a pair of pinion gears 77, 79 for connecting them, storing holes 73, 75 for storing them slidably and turnably and a drive shaft 29 for transmitting the drive force of an engine to the differential case 31, after penetrating the side gear 41 and meshing with the torque input part 69. The axial direction ranges 97, 99 in which only either one of the pinion gears 77, 79 exists in the diameter direction is installed in the torque input part 69.

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 for a vehicle.

[0002]

2. Description of the Related Art German Patent Publication DE 40132
01A1 describes a differential device 201 as shown in FIG.

This differential device 201 includes an output side gear 2 arranged inside a differential case 203.
05, 207, the output shafts 209, 211 respectively connected to the side gears 205, 207, and the side gears 205,
A plurality of pinion gears 213 and 215 that mesh with each other and mesh with each other, and a side gear 205.
The drive shaft 219 and the like are engaged with the torque input portion 217 of the differential case 203 between the two. The pinion gears 213 and 215 are slidably and rotatably housed in the housing holes 221 and 223 of the differential case 203.

The driving force of the engine is input from the drive shaft 219 to the differential case 203 via the torque input section 217, and is distributed to the wheel side from each pinion gear set via the side gears 205 and 207 and the output shafts 209 and 211.

At this time, the differential limiting force is obtained by the sliding resistance between the storage holes 221 and 223 and the pinion gears 213 and 215.

Further, like the differential device 201, the drive shaft 219 penetrating through the center to the differential case 2 is inserted.
The structure for transmitting torque to 03 can have a small diameter.

[0007]

However, the drive shaft 21
Torque input unit 2 into which the driving force of the engine is input via 9
Both the storage holes 221 and 223 of the pinion gears 213 and 215 are provided in the radial direction of 17, and the drive force input from the torque input unit 217 is transmitted inside the differential case 203 by these storage holes 221 and 223. Since a large notch is formed in the driving force transmission path, it is difficult to transmit a large torque.

Further, the driving force input from the torque input portion 217 is transmitted from the narrow portion 225 to the solid portion 227 in the radial direction. Since a twisting force is applied to the narrow portion 225, the driving force transmission path is provided. Not as valid.

Therefore, in a four-wheel drive vehicle, the transmission torques of the front differential (the differential device that distributes the driving force of the engine to both front wheels) and the rear differential (the differential device that distributes the driving force of the engine to both rear wheels) are transmitted. Center differential that transmits the large total torque (differential device that distributes engine drive force to the front and rear wheels)
It is not suitable for handling large differential limiting force.

Therefore, the present invention is a differential device in which the driving force of the engine is transmitted from the drive shaft penetrating into the central portion to the differential case, and the driving force transmission path inside the differential case is strengthened to enable transmission of a large torque. The purpose of the present invention is to provide a differential device.

[0011]

According to another aspect of the present invention, there is provided a differential device having a pair of output side gears arranged axially on both sides of a torque input portion formed on a differential case, and radially outside the side gears. At least a pair of pinion gears each having a first gear portion that meshes with the side gear and a second gear portion that meshes with each other, a storage hole formed in the differential case for slidably and rotatably storing each pinion gear, and penetrating one side gear. A drive shaft that meshes with the torque input portion of the differential case and transmits the driving force of the engine to the differential case, and the torque input portion is provided with an axial range in which only one of the two pinion gears exists in the radial direction. Is characterized by.

The driving force of the engine rotates the differential case from the drive shaft via the torque input section, is distributed from the pinion gears to the wheels via the side gears and the output shaft, and the wheels are driven while traveling on a bad road. When a driving resistance difference is generated between them, the driving force of the engine is differentially distributed to each wheel side by the rotation of the pinion gear.

At this time, a torque sensitive type differential limiting function can be obtained by the frictional resistance between the pinion gear and the housing hole.

In addition to this, the torque input portion provided on the differential case is provided with an axial range in which only one of the two pinion gears exists in the radial direction, so that the driving force input from the torque input portion is transmitted to the differential case. The driving force transmission path that is transmitted inside the vehicle is enhanced accordingly.

Thus, a large torque can be transmitted inside the differential case, and a large differential limiting force can be used not only for the front differential and the rear differential but also for the center differential.

Further, the structure in which the diff case is rotated through the drive shaft penetrating in the center is advantageous in that the device has a smaller diameter than the structure in which the diff case is rotated through a large-diameter ring gear.

According to a second aspect of the present invention, there is provided the differential device according to the first aspect, wherein the pinion gears have equal lengths to each other, and these second gear portions mesh with each other on the inner side in the axial direction of both side gears. Thus, an effect equivalent to that of the first aspect is obtained.

In addition to this, since the pinion gears have the same length, it is easy to provide the torque input portion at the axial center portion of the differential case. Thus, the torque input portion is provided at the axial center portion of the differential case. By doing so, the torque (twist) applied from the torque input section to both axial ends of the differential case becomes uniform, so that, for example, the meshing of the gears is kept good, noise is prevented, and the durability of the differential device is improved. .

According to a third aspect of the present invention, there is provided the differential device according to the first aspect, wherein a long pinion gear having a shaft portion having a small diameter which avoids interference with a side gear is provided between the first gear portion and the second gear portion, A pair of pinion gears is configured by a short pinion gear having no shaft portion between the first gear portion and the second gear portion, and these second gear portions are meshed with each other on the outer side in the axial direction of both side gears. An effect equivalent to that of the first aspect is obtained.

In addition to this, by engaging the respective pinion gears on the outer side in the axial direction of the both side gears, it is possible to widen the axial range of the torque input portion in which only one of the two pinion gears exists in the radial direction. Moreover, it enables transmission of large torque.

A fourth aspect of the present invention is the differential device according to the third aspect, wherein the centering portion of the side gear is provided on the outer periphery of the torque input portion outside the axial range in which only one of the two pinion gears exists in the radial direction. Is provided, and an effect equivalent to that of the configuration of claim 3 is obtained.

In addition to this, the fact that the torque input section is arranged between both side gears and the centering section of the side gear is provided in this torque input section improves the supporting state of this side gear. .

Further, since the torque input section is extended to the side gear side of the other side only by this centering section, the axial center of the torque input section can be brought closer to the axial center of the differential case, and a balance is provided inside the differential case. Good driving force can be transmitted.

The invention of claim 5 is the differential device according to any one of claims 1 to 4, wherein one of both side gears is connected to the front wheel side and the other of the both side gears is the rear wheel side. And the same effect as the configuration of any one of claims 1 to 4 is obtained.

In addition to this, the differential device of the present invention in which the drive force transmission path for transmitting the drive force input from the drive shaft to the torque input section inside the differential case is strengthened is suitable for a center differential that handles a large torque. .

The invention according to claim 6 is the differential device according to any one of claims 1 to 5, wherein the differential case comprises a casing body and covers fixed to both axial sides thereof. The casing main body is provided with a torque input portion and a storage hole for each side gear that is opened on both sides in the axial direction, and an effect equivalent to that of the configuration according to any one of claims 1 to 5 is obtained.

Since the differential case is provided with the torque input section, each side gear must be attached to the differential case from both sides in the axial direction of the torque input section. In this way, the differential case is fixed to the casing body and both axial sides thereof. If it is configured with a cover, the casing main body can be provided with a torque input portion and a storage hole for each side gear opened on both axial sides, and each side gear can be attached from both axial sides of the torque input portion. .

Further, it is possible to use the same cover on one side and the other side, and the number of parts is reduced.

Further, in the structure in which the respective pinion gears are equal in length to each other as in claim 2, the casing body can be made symmetrical with respect to the central axis, so that the casing body is easy to process and the cost is low.

The invention according to claim 7 is the differential device according to any one of claims 1 to 6, characterized in that an oil passage for guiding oil to the inside of the differential case is formed on the drive shaft. An effect equivalent to that of the configuration according to any one of claims 1 to 6 is obtained.

In addition to this, since the drive shaft penetrates into the center of the differential case and an oil passage is provided in this drive shaft, the oil can be sent to the center of the differential case. The parts and the sliding parts are effectively lubricated, and the durability of the differential device is greatly improved.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described with reference to FIGS. 1 to 3 and 5. This embodiment has the features of claims 1, 2, 5, 6, and 7, FIG. 1 shows a differential device of this embodiment, and FIG. 5 shows a power system of a four-wheel drive vehicle using this differential device. Is shown. The left and right directions are the left and right directions of this vehicle, and the left side of FIG. 1 corresponds to the front of this vehicle. Further, members and the like not given reference numerals are not shown.

As shown in FIG. 5, this power system includes an engine 1, a transmission 3, an oil pump 5, a transfer 7, front and rear propeller shafts 9 and 11, a front differential 13, a rear differential 15, left and right front wheels 17 and 19, right and left. The rear wheels 21 and 23 are included.

The transfer 7 is composed of a center differential 25 (differential device of this embodiment), a chain transmission mechanism 27, and the like.

The driving force of the engine 1 is transmitted from the transmission 3 via the drive shaft 29 to the oil pump 5 and is transmitted to the center differential 25, and is distributed from the center differential 25 to the front wheel side and the rear wheel side. . The driving force distributed to the front wheels is transmitted from the chain transmission mechanism 27 and the propeller shaft 9 to the front differential 13, and is distributed from the front differential 13 to the left and right front wheels 17 and 19. The driving force distributed to the rear wheel side is transmitted from the propeller shaft 11 to the rear differential gear 15, and is transmitted from the rear differential gear 15 to the left and right rear wheels 2.
It is distributed to 1, 23.

As shown in FIG. 1, the differential case 31 of the center differential 25 is constructed by fixing covers 35 to the axially opposite sides of the casing body 33 with bolts 37.
Each cover 35 and the casing body 33 are centered by a centering portion 39.

Inside the differential case 31, output side gears 41 and 4 of the same diameter, which are helical gears, are provided.
3 are arranged.

A hollow output shaft 45 is integrally formed with the side gear 41, and an output shaft 47 is integrally formed with the side gear 43. Each output shaft 45, 47 is a cover 35,
35 are rotatably supported by the differential case 31 by bearings 49 and 51 provided between the differential case 31 and the bearing 35.

The output shafts 45 and 47 are spline-connected to the front and rear wheel transmission shafts 53 and 55, respectively. As shown in FIG. 5, these transmission shafts 53 and 55 are ball bearings 57 and 59. By Transfer Case 61
It is supported by The chain transmission mechanism 2 is attached to the transmission shaft 53.
One of the seven sprockets 63 is formed, and the transmission shaft 55 is connected to the propeller shaft 11 side.

The casing body 33 includes the side gears 4
Storage holes 65 and 67 are formed at both ends in the axial direction to store the first and the third holes. Also, the casing body 3
3 includes a torque input section 6 between the side gears 41 and 43.
9 is formed, and thrust washers 71 are arranged between the torque input section 69 and the side gears 41 and 43, respectively.

The drive shaft 29 penetrates the differential case 31 through the hollow output shaft 45 and the side gear 41, and is spline-connected to the torque input section 69.

The differential case 31 has storage holes 73 and 75,
As shown in FIG. 2, four sets are formed in the circumferential direction, and the accommodation holes 73 and 75 are respectively provided in the helical pinion gears 7.
7, 79 are housed so as to be slidably rotatable.

Each pinion gear 77, 79 comprises a first gear portion 81, 83 and a second gear portion 85, 87, respectively. The first gear portion 81, 83 meshes with the side gears 41, 43 respectively, 2 gears 85 and 87 are side gears 4
They mesh with each other on the inner side in the axial direction of 1, 43.

The driving force of the engine 1 for rotating the differential case 31 is from the pinion gears 77, 79 to the side gear 4
If the driving resistance difference is generated between the front and rear wheels while traveling on a bad road, etc., as described above, the pinion gears 7 are distributed to the front diff 13 side and the rear diff 15 side via the Nos. 1 and 43.
Due to the rotation of 7, 79, the driving force of the engine 1 is differentially distributed to the front and rear sides.

Since the side gears 41 and 43 have the same pitch circle diameter, the torques distributed to the front and rear wheels are equal (equal torque distribution type).

During transmission of torque, each pinion gear 77, 7
The tooth tip of 9 is pressed against the wall surfaces of the storage holes 73 and 75 by the reaction force of meshing with the side gears 41 and 43 to generate frictional resistance. Further, due to the meshing thrust force of the helical gear, frictional resistance is generated between the end faces of the pinion gears 77 and 79 and the differential case 31, and the side gears 41 and 43 and the torque input portion 69 of the differential case 31 are connected via the thrust washer 71. Friction resistance occurs between the side gears 41 and 43 and the cover 35.

Due to these frictional resistances, a torque sensitive differential limiting function can be obtained.

The gears are positioned so that their meshing thrust forces are all canceled inside the differential case 31. Therefore, the gear meshing thrust forces do not give axial force to the differential case 31.

Also, the drive shaft 2 penetrating the differential case 31.
9, an oil passage 89 is provided, and the output shaft 47 of the side gear 43 has an oil sump 91 communicating with the oil passage 89.
Are formed.

The oil from the oil pump 5 driven by the rotation of the drive shaft 29 is guided to the oil sump 91 inside the differential case 31 through the oil passage 89 and the oil sump 91.
The oil is supplied to the meshing portions of the gears and the lubrication portions such as the storage holes 73 and 75 by the centrifugal force caused by the rotation of the differential case 31, and the openings 100 formed in the casing body 33 outside the pinion gears 77 and 79. A lubrication path released from 102 is formed to provide effective lubrication.

As shown in FIG. 1, in the axial range 93 of the torque input portion 69 of the differential case 31, as shown in FIG. 2, both pinion gears 77 and 79 (accommodating holes 73 and 7) are arranged radially outward.
5) is arranged in the axial direction 95, the axial direction range 97 in which only the pinion gear 77 (storage hole 73) is arranged in the radial outside, and the pinion gear 7 in the radial outside as shown in FIG.
An axial range 99 in which only 9 (storage hole 75) is arranged is formed.

The respective axial ranges 95, 97, 99 are evenly distributed on both sides in the axial direction with respect to the axial center 101 of the differential case 31, and the axial center of the torque input portion 69 is on the axial center 101 of the differential case 31. It is in.

In the axial range 95, the driving force transmission path 103 from the torque input section 69 is narrow as shown in FIG. 2, whereas in the axial range 97, as shown in FIG. Since only the pinion gear 77 is arranged in the above, the driving force transmission path 105 is wide. Similarly, a wide drive force transmission path is formed in the axial range 99.

The assembling order of the center differential 25 is as follows. First, the side gear 41 and the pinion gear 77 are mounted in the housing holes 65 and 73 of the casing body 33, respectively.
7 and 75 have side gear 43 and pinion gear 79, respectively.
After installing the cover 35 on both sides of the casing body 33.
Are fixed with bolts 37.

In this way, the center differential 25 is constructed.

In the vehicle equipped with the center differential 25, the behavior of the vehicle body when a large torque is applied such as at the time of starting or accelerating is improved by the torque sensitive differential limiting function.

In addition to this, the torque input portion 69 is provided with the axial ranges 97 and 99 in which only one of the two pinion gears 77 and 79 exists in the radial direction. It has been reinforced to enable transmission of large torque.

Therefore, the front differential 13 and the rear differential 15
It is suitable for the center differential 25 that handles a large torque obtained by summing the respective transmission torques, and a large differential limiting force can be handled by using the center differential 25.

In addition, in the structure in which the differential case 31 is rotated via the drive shaft 29 penetrating in the center as described above, the diameter of the center differential 25 is smaller than that in the structure in which the differential case is rotated via a large-diameter ring gear. Advantageously, the diameter of the transfer 7 can be reduced.

Further, since the pinion gears 77 and 79 are made equal in length, the torque input section 69 is attached to the differential case 31.
It becomes easier to provide the torque input portion 69 at the center portion of the differential case 31 in the axial direction, and the torque (twist) applied to both axial ends of the differential case 31 at the time of torque input is provided. Become even.

Therefore, the meshing of the gears is kept good, noise is prevented, and the durability of the center differential 25 is improved.

Further, the torque input section 6 is provided on the differential case 31.
9, the side gears 41 and 43 must be attached to the differential case 31 from both sides of the torque input section 69 in the axial direction.

Therefore, since the differential case 31 is composed of the casing body 33 and the covers 35 fixed to both sides in the axial direction thereof, the torque input portion 69 is attached to the casing body 33.
And the storage holes 65 and 67 of the side gears 41 and 43 opened on both sides in the axial direction, respectively.
1, 43 can be attached from both sides in the axial direction of the torque input section 69.

Further, since the covers 35 on one side and the other side are the same, the number of parts is reduced.

Further, since the pinion gears 77, 79 are equal in length to each other, the casing body 33 can be made symmetrical with respect to the central axis, the casing body 33 can be easily processed, and the cost can be reduced.

In addition to this, the drive shaft 29 has a differential case 3
1 is used to connect the oil passage 8 to the drive shaft 29.
By providing 9, the oil is sent to the center of the differential case 31, the meshing portions of the gears and the sliding portions are effectively lubricated, and the durability of the center differential 25 is greatly improved.

Further, as described above, the gears are positioned so that the meshing thrust forces are all canceled inside the differential case 31, and no axial force is applied to the differential case 31, so only the radial force is applied. The center differential 25 can be supported by the inexpensive ball bearings 57 and 59 to be received, and the cost can be reduced accordingly.

Next, a second embodiment of the present invention will be described with reference to FIGS. This embodiment is claimed in claims 1, 3, 4,
It has the features of 5 and 6, and FIG. 4 shows the differential device of this embodiment. Similar to the first embodiment, this embodiment is used for the center differential 107 in the vehicle shown in FIG.

As shown in FIG. 4, the differential case 109 of the center differential 107 is formed by fixing covers 113 and 115 to the axially opposite sides of the casing body 111 with bolts 117, respectively. The covers 113 and 115 and the casing body 111 are centered by a centering portion 119.

Inside the differential case 109, the output side gears 12 each having the same diameter are formed of helical gears.
1, 123 are arranged.

The side gear 121 has a hollow output shaft 125.
Is integrally formed, and the output shaft 1 is attached to the side gear 123.
27 is integrally formed. The output shafts 125 and 127 are the bearings 12 provided between them and the covers 113 and 115.
9 and 131 are rotatably supported on the differential case 109, respectively.

The output shafts 125 and 127 are spline-connected to the front-wheel-side and rear-wheel-side transmission shafts 53 and 55, respectively.

The casing main body 111 is provided with a storage hole 133 opened at both ends in the axial direction for storing the side gears 121 and 123, and another storage hole. Also,
The casing body 111 includes the side gears 121, 12
3, a torque input portion 135 is formed, thrust washers 137 and 139 are arranged between the torque input portion 135 and the side gears 121 and 123, respectively, and between the side gear 123 and the cover 115. Thrust washer 140 is arranged.

The torque input section 135 has a centering section 1
41 is provided to support and center the inner circumference of the side gear 123.

Also, the hollow output shaft 125 and the side gear 1
21, the drive shaft 143 penetrates the differential case 109, and is spline-connected to the torque input section 135.

The differential case 109 has long and short storage holes 14
Four sets 5 and 147 are formed in the circumferential direction, and long and short helical pinion gears 149 and 151 are slidably and rotatably housed in these housing holes 145 and 147, respectively.

The long pinion gear 149 is the first gear portion 1
53, a second gear portion 155, and a small-diameter shaft portion 157 connecting them, and the short pinion gear 151 has first and second gear portions 159 and 161 having no shaft portion between them.
Consists of

The first gear portions 153 and 159 of the pinion gears 149 and 151 mesh with the side gears 121 and 123, respectively, and the second gear portions 155 and 161 include the side gear 12.
Outside of 3 mesh with each other.

Engine 1 for rotating differential case 109
Driving force is distributed from the pinion gears 149, 151 to the front differential 13 side and the rear differential 15 side via the side gears 121, 123, and if a driving resistance difference occurs between the front and rear wheels during traveling on a bad road or the like. , Each pinion gear 14
Due to the rotation of 9, 151, the driving force of the engine 1 is differentially distributed to the front and rear sides.

Since the pitch circle diameters of the side gears 121 and 123 are equal, the torques distributed to the front wheel side and the rear wheel side are equal (torque equal distribution type).

During transmission of torque, each pinion gear 149,
The tooth tips of 151 are pressed against the wall surfaces of the storage holes 145, 147 by the reaction force of meshing with the side gears 121, 123, and frictional resistance is generated. In addition, the meshing thrust force of the helical gear causes each pinion gear 14
Friction resistance is generated between the end faces of 9, 151 and the differential case 109, and friction resistance is generated between the side gears 121, 123 and the torque input portion 135 of the differential case 109 via the thrust washers 137, 139. ,
Between the side gear 121 and the cover 113, and via the thrust washer 140, the side gear 123 and the cover 11
Frictional resistance is generated between 5 and 5.

Due to these frictional resistances, a torque sensitive differential limiting function can be obtained.

The gears are positioned so that their meshing thrust forces are all canceled inside the differential case 109. Therefore, the gear meshing thrust forces do not give a force to the differential case 109 in the axial direction.

As shown in FIG. 4, in the axial range 163 of the torque input portion 135 of the differential case 109, both pinion gears 149 and 151 (accommodating holes 145 and 14) are arranged radially outward.
7) in the axial direction 165 and the axial range 1 in which only the pinion gear 149 (the accommodation hole 145) is arranged radially outward, as in the state of FIG. 3 in the first embodiment.
67 are formed.

In the axial range 165, since both pinion gears 149 and 151 are arranged radially outward,
The drive force transmission path from the torque input portion 135 is narrow, whereas in the axial range 167, only the pinion gear 149 is arranged radially outward, so the drive force transmission path is wide.

Further, the drive shaft 143 penetrating the differential case 109 is provided with an oil passage 180, and the side gear 1
An oil reservoir 179 communicating with the oil passage 180 is formed on the output shaft 127 of No. 23.

The oil from the oil pump 5 driven by the rotation of the drive shaft 143 is guided to the oil reservoir 179 inside the differential case 109 through the oil passage 180, and the oil in the oil reservoir 179 is centrifuged by the rotation of the differential case 109. Depending on the force, the meshing parts of the gears and the storage holes 145, 1
Is supplied to the lubrication part such as 47, each pinion gear 149,
Lubrication paths that are discharged from the openings 182 and 181 formed in the casing body 111 outside the 151 are formed to perform effective lubrication.

The assembling order of the center differential 107 is as follows.
The side gears 121 and 123 are attached to the storage holes for the pinion gear 14 respectively.
After mounting 9, 151, the covers 113, 115 are fixed to the both sides of the casing body 111 with bolts 117.

In this way, the center differential 107 is constructed.

In the vehicle equipped with the center differential 107, the behavior of the vehicle body when a large torque is applied such as when starting or accelerating is improved by the torque-sensitive differential limiting function.

In addition to this, the torque input section 135 has an axial range 1 in which only the pinion gear 149 exists in the radial direction.
By providing 67, the entire driving force transmission path is strengthened, and a large torque can be transmitted accordingly.

Since the pinion gears 149 and 151 are meshed with each other on the outside of the side gear 123, the above-mentioned axial range 1 provided inside the side gears 121 and 123.
67 can be widened, and a large torque can be transmitted.

Therefore, the front differential 13 and the rear differential 15
It is suitable for the center differential 25 that handles a large torque obtained by summing the respective transmission torques, and a large differential limiting force can be handled by using the center differential 25.

In the structure in which the diff case 109 is rotated through the drive shaft 143 penetrating in the center, the diameter of the center diff 107 is smaller than that in the structure in which the diff case is rotated through a ring gear having a large diameter. This is advantageous because the diameter can be reduced.

In addition to this, the fact that the torque input portion 135 is arranged inside the side gears 121 and 123 is utilized, and the centering portion 141 of the side gear 123 is provided in this torque input portion 135, whereby the side gear 123 Improves support.

Further, since the torque input portion 135 is extended to the side gear 123 side by the width of the centering portion 141, the axial center of the torque input portion 135 can be brought closer to the axial center of the differential case 109, and the differential case A well-balanced driving force transmission can be performed inside 109.

Further, as described above, the gears are positioned so that the meshing thrust forces are all canceled inside the differential case 109. Since no axial force is applied to the differential case 109, only radial force is applied. The center differential 107 can be supported by the inexpensive ball bearings 57 and 59 to be received, and the cost can be reduced accordingly.

The differential device of the present invention may be constructed by a spur gear instead of a helical gear.

Further, the differential device of the present invention is
The side gears may have different diameters, and may be of an uneven torque distribution type.

The differential device of the present invention can be used for any of a center differential, a front differential and a rear differential.

[0101]

According to the differential device of the first aspect of the present invention, the torque input portion provided in the differential case is provided with an axial range in which only one of the two pinion gears exists in the radial direction. The strength of the transmission path is strengthened to that extent, enabling transmission of large torque,
Not only front differential and rear differential but also center differential can handle large differential limiting force.

Further, the structure in which the differential case is rotated through the drive shaft penetrating in the center is advantageous because the diameter of the device is reduced.

According to the differential device of the second aspect, the same effect as that of the first aspect can be obtained, and the pinion gears have the same length, so that the torque input portion can be easily provided at the central portion in the axial direction of the differential case. As a result, the torque (twist) applied from the torque input section to both axial ends of the differential case is made uniform, the meshing of the gears is maintained well, noise is prevented, and the durability of the differential device is improved.

According to the differential device of the third aspect of the present invention, the same effect as that of the first aspect can be obtained, and the pinion gears are meshed with each other on the axially outer sides of the both side gears, so that only one of the two pinion gears is radially arranged. It is possible to widen the axial range of the torque input part where
Further, it enables transmission of large torque.

The differential device according to claim 4 obtains the same effect as that of the structure according to claim 3, and utilizes the fact that the torque input portion is arranged between both side gears. By providing the centering part of the side gear, the supporting condition of this side gear is improved accordingly.

Further, since the torque input portion is extended to the side gear side on the other side by the width of the centering portion, the axial center of the torque input portion can be brought closer to the axial center of the differential case, and inside the differential case. A well-balanced driving force can be transmitted.

The differential device according to claim 5 has the same effect as that of the structure according to any one of claims 1 to 4, and the transmission path of the driving force input from the drive shaft to the torque input portion of the differential case is provided. The enhanced configuration of the present invention is
Suitable for center differentials that handle large torque.

A differential device according to a sixth aspect of the present invention has the same effects as those of the first to fifth aspects of the present invention, and includes a differential case including a casing body and covers fixed to both axial sides thereof. Since the casing body is provided with the torque input section and the accommodation holes for the side gears that are open on both sides in the axial direction, the side gears can be attached from both sides in the axial direction of the torque input section, and one side and the other side. It is possible to make the side covers the same, which reduces the number of parts accordingly.

Further, in the structure in which the respective pinion gears are equal in length to each other as in claim 2, the casing body can be made symmetrical with respect to the center, so that the casing body is easy to process and the cost is low.

The differential device according to claim 7 obtains the same effect as that of the structure according to any one of claims 1 to 6 and utilizes the fact that the drive shaft penetrates into the center of the differential case. Since the oil passage is provided in the differential case, the oil can be sent to the center of the differential case, so that the meshing portions of the gears and the sliding portions are effectively lubricated, and the durability of the differential device is greatly improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is a skeleton mechanism diagram showing a power system of a vehicle using each embodiment.

FIG. 6 is a sectional view of a conventional example.

[Explanation of symbols]

25, 107 Center differential (differential device of each embodiment) 29, 143 Drive shaft 31, 109 Differential case 33, 111 Casing main body 35, 113, 115 Cover 41, 43, 121, 123 Output side helical side gear 65, 67, 133 Helical side gear storage hole 69,135 Differential case torque input section 73,75,145,147 Helical pinion gear storage hole 77,79,149,151 Helical pinion gear 81,83,153,159 First gear section 85,87,155 , 161 Second gear part 89, 180 Oil passage 97, 99, 167 Axial range in which only one of both pinion gears exists in the radial direction 157 Small-diameter shaft part

Claims (7)

[Claims] 1. A pair of output side gears arranged on both sides in the axial direction of a torque input portion formed in a differential case, a first gear portion arranged radially outside of these side gears, and meshing with the side gears respectively and with each other. At least a pair of pinion gears each having a second gear portion;
A storage hole formed in the differential case to store each pinion gear slidably and rotatably, and a drive shaft that penetrates the side gear on one side and meshes with the torque input portion of the differential case to transmit the driving force of the engine to the differential case, A differential device characterized in that an axial range in which only one of the two pinion gears is present in the radial direction is provided in the torque input section. 2. The differential device according to claim 1, wherein the pinion gears are of equal length to each other, and the second gear portions mesh with each other on the inner side in the axial direction of both side gears. 3. The differential device according to claim 1, wherein a long pinion gear having a shaft portion having a small diameter that avoids interference with a side gear is provided between the first gear portion and the second gear portion, and the first gear portion. A differential device characterized in that a pair of pinion gears is constituted by a short pinion gear having no shaft portion between the second gear portion and the second gear portion, and these second gear portions mesh with each other on the axially outer sides of both side gears. 4. The differential device according to claim 3, wherein the centering portion of the side gear is provided on the outer periphery of the torque input portion other than the axial range in which only one of the two pinion gears exists in the radial direction. Characteristic differential device. 5. The differential device according to claim 1, wherein one of both side gears is connected to a front wheel side and the other of both side gears is connected to a rear wheel side. Differential device. 6. The differential device according to claim 1, wherein the differential case includes a casing main body and covers fixed to both axial sides of the casing main body. A differential device characterized in that an accommodation hole for each side gear that is open on both sides in the input section and the axial direction is provided. 7. The differential device according to any one of claims 1 to 6, wherein an oil passage for guiding oil is formed on the drive shaft inside the differential case.