JPH0734247U - Differential device - Google Patents

Abstract

(57) [Summary] [Purpose] To increase the difference in the differential limiting force between forward and reverse travel of the vehicle. The differential device 7 of the present invention comprises a differential case 21 which is rotationally driven by an engine, helical pinion gears 49 and 51 which are slidably stored in storage holes 45 and 47 of the differential case 21, and a pinion gear 4.
Helical side gear 31, which is connected via 9, 51,
33 and a bearing 67 for receiving an outward meshing thrust force generated in the side gears 31, 33.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vehicle differential device.

[0002]

[Prior art]

 Japanese Unexamined Patent Publication (Kokai) No. 63-76938 discloses a differential device 201 as shown in FIG. This is a differential case 203 that is rotated by the driving force of the engine, helical pinion gears 209 and 211 that are slidably rotatably arranged in storage holes 205 and 207 provided in the differential case 203, and a helical that is connected via these. The side gears 213 and 215 are provided. The driving force of the engine that rotates the differential case 203 is distributed to the wheel side from the pinion gears 209 and 211 via the side gears 213 and 215. At this time, the frictional resistance generated between the pinion gears 209 and 211 and the storage holes 205 and 207 and the thrust force of meshing with the pinion gears 209 and 211 cause the clearance between the side gears 213 and 215 or between the side gears 213 and 215 and the differential case 203. The operation is limited by the frictional resistance generated between them.

[0003]

[Problems to be solved by the device]

7 and 8 are skeleton diagrams of the differential device 201. In the following description, T is the engine torque input to the side gears 213, 215, R _t is the transfer ratio, γ is the pitch radius of the side gears 213, 215, and β is the twist angle of the side gears 213, 215. The transfer ratio is the driving force sent to the grip side (ground side) wheel with respect to the driving force sent to the slip side (idling side) wheel when one side of the wheel to which the side gears 213 and 215 are respectively connected idle. Is a ratio and is a value representing the magnitude of the differential limiting force of the differential device. The difference between R _t during forward vehicle and the reverse when R _t, for example it is desired to increase in order to avoid interference with the ABS (anti-lock brake system). Further, the meshing thrust force F _G generated on the side gear on the grip side and the meshing thrust force F _S generated on the side gear on the slip side are calculated by the formulas 1 and 2, respectively.

[0004]

## EQU1 ## F _G = T × R _t / (R _t +1) × 1 / γ × tan β

## EQU2 ## F _S = T × 1 / (R _t +1) × 1 / γ × tan β The side gears 213 and 215 are given different twist angles, so that the directions of F _G and F _S are always In the opposite direction, the directions of F _G and F _S are reversed when the vehicle moves forward and backward as the rotation direction of the differential case 203 changes. 7 and 8, the side gear 213 is on the grip side and the side gear 215 is on the slip side.

FIG. 7 shows a state in which the side gear 215 idles in the rotation direction of the differential case 203 indicated by the arrow 217, and outward thrust forces F _G and F _S are generated on the side gears 213 and 215, and the side gear 215 is pressed against the differential case 203 side. Is. At this time, the differential limiting force generated by the side gears 213 and 215 has a magnitude corresponding to the sum of the thrust forces F _G and F _S. Further, in FIG. 8, the rotation direction of the differential case 203 is reversed from the state of FIG. 7, the side gear 215 rotates in the direction of the arrow 219, and the thrust forces F _G , F _{S of the} side gears 213, 215 become inward. Differential limit force by the side gears 213 and 215 at this time the torque corresponding to the side gear 213 in the thrust force F _G, the side gears 21 5 The torque corresponding to the thrust force _{F G + (F G -F S} ) is generated Therefore, it is larger than the state of FIG. 7 by 2 (F _G −F _S ). In general, FIG. 7 with a small R _t is the state when the vehicle is moving backward, and FIG. 8 is the state with a large R _t is the state when the vehicle is moving forward.

Here, in order to increase the difference between R _t when moving forward and R _t when moving backward, for example, needle bearings are provided at positions indicated by arrows 221 and 223 in FIG. 7 (between the side gears 213 and 215 and the differential case 203). If an attempt is made to further reduce R _t by arranging such elements as above, the needle bearing on the side gear 213 side, which is subjected to a large thrust force F _G on the grip side, receives an overload and is damaged or the durability deteriorates. Also, since R _t decreases thrust force in Saidogi Ya 215 side (F _G -F _S) according to the differential limiting force is canceled by the needle bearings in the state of FIG. 8, the difference between the forward and reverse R _t I can't make it big.

Therefore, an object of the present invention is to provide a differential device in which the difference in differential limiting force between the forward movement and the reverse movement of the vehicle is increased.

[0008]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention relates to a differential case that is rotationally driven by the driving force of an engine, a helical pinion gear that is slidably stored in a storage hole provided in the differential case, and is connected to the wheel side. And a pair of helical pinion gears that are connected to each other via a pinion gear, and a bearing that receives an outward meshing thrust force generated in each helical side gear by meshing with the helical pinion gear.

[0009]

[Action]

A small state with R _t thrust force outward occurs in the side gears, with applied to the opposite direction to the thrust force F _S gas last force F _G of the slip side gears on the grip side gears through a bearing, the slip side Then, the frictional resistance due to the thrust force F _S does not occur. Thus, as compared with the conventional example in which the differential limiting force due to (F _G + F _S ) is generated, the effective thrust force is only ( _{G G} −F _S ) on the grip side, and R _t can be significantly reduced. Further, the thrust force applied to the bearing at this time is a small thrust force F _S on the slip side, so that damage to the bearing and deterioration of durability due to overload can be avoided.

[0010] In a large state of inward R _t thrust force is generated in the side gears, bearings large kina differential by the sum of F _G and F _G + do not participate in the transmission of the thrust force (F _G -F _S) Limited power is obtained.

By arranging the bearing that receives these tensile forces between the side gears in this manner, the bearing can be protected and the difference in R _t between when the vehicle is moving forward and when the vehicle is moving backward can be significantly widened.

[0012]

【Example】

 The first embodiment will be described with reference to FIGS. FIG. 1 shows this embodiment, and FIG. 4 shows the power system of a vehicle using the differential device of this embodiment. The left and right directions are the left and right directions in this vehicle and FIGS. 1 to 3.

As shown in FIG. 4, this power system includes an engine, a transmission 3, a propeller shaft 5, a rear differential 7 (a differential device of FIG. 1 arranged on the rear wheel side), rear axles 9, 11 and left and right rear wheels. 13, 15 and left and right front wheels 17, 19 and the like.

The differential case 21 of the rear differential is arranged in the differential carrier 23, and the ring gear 25 is fixed to the differential case 21. The ring gear 25 meshes with a drive pinion gear 27, and 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 rotationally drives the differential case 21 from the transmission 3 via the propeller shaft 5. The differential carrier 23 is filled with oil to form an oil reservoir.

As shown in FIG. 1, inside the differential case 21, hollow helical side gears 31, 33 are arranged. The side gears 31 and 33 are rotatably supported by shaft supporting portions 35 and 37 formed between the side gears 31 and 33, and the free ends are supported by the shaft supporting portions 39 formed between the center gears. is doing. The left and right side gears 31, 33 are spline-coupled to the left and right rear axles 9, 11 respectively so as to be axially movable. A washer 41 is arranged between the side gears 31 and 33, and washers 43 and 43 are arranged between the side gears 31 and 33 and the differential case 21, respectively.

A plurality of sets of storage holes 45, 47 are provided in the differential case 21 in the circumferential direction, and long and short helical pinion gears 49, 51 are slidably stored therein. The long pinion gear 49 includes first and second gear parts 53, 55 and a small diameter shaft part 57 connecting them, and the second gear part 55 meshes with the right side gear 33. The left end portion of the short pinion gear 51 meshes with the first gear portion 53, and the right end portion meshes with the left side gear 31.

A hub 63 including a column portion 59 and a flange portion 61 is arranged on the inner peripheral side of each of the side gears 31 and 33. A retaining ring 65 is inserted into the column portion 59 and is attached to the left side of the flange portion 61. A needle bearing 67 (bearing) is arranged in the. The convex portion 69 of the side gear 31 is arranged on the right side of the retaining ring 65, and the convex portion 71 of the side gear 33 is arranged on the left side of the needle bearing 67. In this way, the side gears 31 and 33 are connected outward via the hub 63, the retaining ring 65, and the bearing 67. Further, a gap is formed between each side gear 31, 33 and the differential case 21 in a state where the respective convex portions 69, 71 are in contact with the retaining ring 65 and the bearing 67, respectively.

The differential case 21 is provided with openings 73, 75, 77 that communicate with the storage holes 45, 47. From these openings 73, 75, 77, oil flows out from the oil reservoir of the differential carrier 23, and Lubricate the gear meshing parts, sliding parts, bearings 67, etc.

In this way, the rear differential 7 is configured, and the driving force of the engine 1 for rotating the differential case 21 is distributed from the respective pinion gears 49, 51 to the left and right rear wheels 13, 15 via the side gears 31, 33, 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 due to the transfer of the pinion gears 49 and 51.

During the transmission of torque, the tooth tips of the pinion gears 49 and 51 are pressed against the wall surfaces of the storage holes 45 and 47 by the reaction force of engagement with the side gears 31 and 33, which causes frictional resistance. 2 and 3, the side gears 31 and 33 are pressed against the differential case 21 side by the mesh thrust forces F _G and F _S with the pinion gears 49 and 51, or they are pressed against each other to cause frictional resistance. Occurs. A torque sensitive differential limiting force is obtained by these frictional resistances.

2 and 3 show the state of the rear differential when the right rear wheel 15 of the vehicle of FIG. 4 is idling in the directions of arrows 79 and 81, respectively. FIG. 2 is when the vehicle is moving backward, and outward meshing thrust forces F _G and F _S are generated in the side gears 31 and 33, respectively. FIG. 3 is when the vehicle is moving forward, and the thrust forces F _G and F _S of the side gears 31 and 33 are inward.

In the state of FIG. 2, the thrust force F _S of the slip side gear 33 is applied in the opposite direction to the side gear 31 on the left rear wheel 13 side, which is the grip side, via the bearing 67, so that the thrust force is (F _G -F _S) and smaller. At this time, the side gear 33 does not come into contact with the differential case 21 due to the above-mentioned gap, so that the differential limiting force is not generated on the side gear 33 side. Thus, unlike the conventional example of FIG. 7 in which the differential limiting force due to F _G + F _S is generated, the effective thrust force is reduced to F _G −F _S , and R _t can be greatly reduced. Further, at this time, unlike the conventional example, the thrust force applied to the bearing 67 is the smaller thrust force F _S , so that damage and deterioration of durability do not occur.

In the state of FIG. 3, since the bearing 67 does not participate in the transmission of thrust force, the large differential limiting force due to the sum of F _G and F _G + (F _G −F _S ) is obtained as in the conventional example of FIG. Occurs, and a large R _t is obtained.

Here, when R _{t is set} to 2.5, the effective thrust force in the state of FIG. 2 becomes 40% of the thrust force of FIG. 7, and as a result, R between the forward and backward movements of the rear differential 7 by the side gear is increased. _{The t} difference is significantly wider than in the conventional example.

When the vehicle of FIG. 4 is running on a rough road or the like, even if one of the rear wheels 13 and 15 runs idle, a large torque is applied to send a large driving force to the other rear wheel via the rear differential 7. , High road running performance is maintained. Further, while traveling on a good road, the steerability is improved by the moderate differential limiting force of the rear differential 7, and smooth and stable traveling and turning characteristics are obtained. Further, during braking, the direction of torque is the same as when traveling in reverse, the differential limiting force is reduced, the binding force between the rear wheels is reduced, and interference with the ABS is avoided when using engine braking.

Next, a second embodiment will be described with reference to FIG. In FIG. 5 and the following description, members having the same functions as those in the first embodiment are designated by the same reference numerals. The left and right directions are the left and right directions in the vehicle of FIG. 4 and FIG.

FIG. 5 shows a differential device of this embodiment, and this differential device is used as the rear differential 83 in the vehicle of FIG.

The ring gear 25 is fixed to the differential case 85, and is rotationally driven by the driving force from the engine 1. Inside the differential case 85, hollow helical side gears 87 and 89 are arranged. The left side gear 87 is welded to the housing 93 of the viscous coupling 91. The housing 93 and the right side gear 89 are spline-coupled to the left and right rear axles 9, 11 respectively so as to be axially movable. The hub 95 of the viscous coupling 91 is spline-connected to the right side gear 89.

The pressure chamber 97 formed between the housing 93 and the hub 95 is filled with high precision silicone oil, and the X rings 99, 99 and the backup ring 101 are provided between the housing 93 and the hub 95. , 101 are arranged to prevent oil leakage. Inside the pressure chamber 97, an outer plate 103 engaged with the housing 93 and an inner plate 105 engaged with the hub 95 are alternately arranged.

As described above, the viscous coupling 91 is arranged between the left and right side gears 87 and 89, and the differential limitation is performed in response to the differential rotation speed between them.

Helical pinion gears 49, 51 are slidably and rotatably housed in the housing holes 107, 109 of the differential case 85. The first gear portion 53 of the pinion gear 49 meshes with the left side gear 87, the left end portion of the pinion gear 51 meshes with the right side gear 89, and the right end portion meshes with the second gear portion 55. At the opening 111 of the differential case 85, the retaining rings 113, 113 and the ring 115 prevent the pinion gears 49, 51 from coming off.

A connecting member 117 is welded to the housing 93 of the viscous coupling 91, and a retaining ring 119 and a ring 121 are attached to the right end portion thereof. A needle bearing 125 (bearing) is arranged between the ring 121 and the convex portion 123 of the right side gear 89. In this way, the side gears 87 and 89 are connected outward via the bear ring 125. A washer 127 is arranged between the side gears 87 and 89, and washers 129 and 131 are arranged between the housing 93 and the side gear 89 with respect to the differential case 85.

The driving force of the engine 1 for rotating the differential case 85 is distributed from the pinion gears 49, 51 to the left and right rear wheels 13, 15 via the side gears 87, 89, and when a difference in driving resistance occurs between the rear wheels, the pinion gears are generated. The driving force of the engine 1 is differentially distributed to the left and right sides by the rotation of 49 and 51. This differential is limited by the differential speed-sensitive differential limiting force of the viscous coupling 91 as the torque-sensitive differential limiting force due to the frictional resistance of each gear.

Since the side gears 87, 89 are connected outward via the bearing 125, a large R _t is obtained when the vehicle is moving forward, in which an inward meshing thrust force is generated in the side gears 87, 89. Further, with the backward movement of the vehicle thrust force of engagement outward occurs R _t is greatly reduced, because when using the engine brake is smaller differential limiting force by the viscous coupling-ring 91, to avoid interference with the ABS Can Further, since the bearing 125 exerts only a small meshing thrust force on the slip side, no damage or deterioration in durability occurs.

Thus, the rear differential 83 is constructed.

Even if one of the rear wheels 13 and 15 of the vehicle shown in FIG. 4 spins on a bad road or the like, a large driving force is generated by the rear differential 83 due to the torque-sensitive and speed-sensitive differential limiting functions as described above. It is sent to the other rear wheel to improve running performance on rough roads, and smooth and stable running performance and turning performance are obtained while running on good roads.

[0037]

[Effect of device]

 In the differential device of this invention, the pair of wheel side helical side gears, which are connected via the helical pinion gears, are connected axially outward through the bearings. When this occurs, the differential limiting force is greatly reduced and interference with the ABS is avoided. Moreover, since the bearing has only a small meshing thrust force of the slip side gear, damage due to excessive load and deterioration of durability do not occur.

[Brief description of drawings]

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

FIG. 2 is a skeleton diagram of the first embodiment showing a state in which an outward meshing thrust force is generated in a side gear.

FIG. 3 is a skeleton diagram of the first embodiment showing a state in which an inward meshing thrust force is generated in a side gear.

FIG. 4 is a skeleton 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 conventional example.

FIG. 7 is a skeleton diagram of a conventional example showing a state in which an outward meshing thrust force is generated in a side gear.

FIG. 8 is a skeleton diagram of a conventional example showing a state in which an inward meshing thrust force is generated in a side gear.

[Explanation of symbols]

7,83 Rear differential (differential device) 21,85 Differential case 31, 33, 87, 89 Helical side gear 45, 47, 107, 109 Storage hole 49, 51 Helical pinion gear 67, 125 Needle bearing (bearing) F _G , F _S meshing Thrust force

Claims (1)

[Scope of utility model registration request] 1. A differential case which is rotationally driven by a driving force of an engine, a helical pinion gear which is slidably rotatably housed in a housing hole provided in the differential case, and each of which is connected to a wheel side and mutually through a pinion gear. A differential device comprising: a pair of connected helical pinion gears; and a bearing that receives an outward meshing thrust force generated in each helical side gear by meshing with the helical pinion gears.