WO2006074679A1

WO2006074679A1 - Differential transmission

Info

Publication number: WO2006074679A1
Application number: PCT/EP2004/014706
Authority: WO
Inventors: Theodor Gassmann
Original assignee: Gkn Driveline International Gmbh
Priority date: 2004-12-24
Filing date: 2004-12-24
Publication date: 2006-07-20
Also published as: DE112004003027A5; DE112004003027B4

Abstract

The invention relates to a differential transmission for use in a vehicle, comprising: a differential case (1) that is mounted to rotate about a longitudinal axis (L); a first driven element (9) and a second driven element (11), which are rotatably mounted in a coaxial manner in the differential case (1); compensating gears (14, 15), which are rotatably mounted in the differential case (1) and which permit a compensatory displacement between the driven elements (9, 11); locking means (17) for generating a braking torque to adapt the speeds of the driven elements (9, 11); and a step-up gear (20), which converts the braking torque to a locking torque that is greater than the braking torque. A first connecting element (21) of the step-up gear (20) is connected to the locking means (17), a second connecting element (22) is connected to the first driven element (9) and a third connecting element (23) is connected to the second driven element (11).

Description

differential gear

description

The invention relates to a differential gear for use in a vehicle with a driven about a longitudinal axis rotatably mounted differential carrier, in which a first output element and a second output element are coaxially mounted, wherein in differential carrier rotatably mounted differential gears with the output elements are in meshing engagement. Furthermore, blocking means for generating a braking torque for speed matching between the output elements are provided. Differential gear of this type can be used as a center differential or axle differential.

Such a differential is known from DE 102 52 012 A1. Among other things, a multi-disc clutch is disclosed as a blocking means. Furthermore, two planetary gears are provided to increase the braking torque. For this purpose, the ring gear of the first planetary gear with the differential carrier, the planet carrier of the first planetary gear with a side shaft and the sun gear of the first planetary gear is connected to the outer disk. Furthermore, the ring gear of the planetary gear is connected to the side shaft, the planet carrier of the second planetary gear with the differential carrier and the sun edge of the second planetary gear with the inner disk of the multi-plate clutch. Thus, a shaft-basket assembly is realized in which the braking torque of the multi-plate clutch is used as a locking torque between the side shaft and the differential carrier. The arrangement of the two planetary gear is translated when a speed difference between the side shaft and the differential carrier occurs in a higher speed difference between the outer disk and the inner disk, so that an increased locking torque is achieved. The disadvantage, however, is the high construction costs. Object of the present invention is to achieve an increase in the locking torque with low structural complexity.

5 The object is comprehensively by a differential gear for use in a vehicle a about a longitudinal axis driven in rotation mounted differential cage, a first output member ^'and a second output member which are coaxially arranged in the differential carrier rotatably, o in the differential carrier is rotatably mounted differential gears, between a compensating movement allow the output elements

Blocking means for generating a braking torque for speed equalization between the output elements and a transmission gear, which translates the braking torque to a 5 compared to this raised locking torque, wherein a first connection element of the transmission gear is connected to the locking means, a second connection element connected to the first output element or by this is formed and a third connection element is connected to the second output ¹ element, solved.

Advantage of this design is that a shaft-shaft arrangement is realized in which the locking torque acts directly between the two output elements. Since! The speed difference between the two output elements is twice as large as between one of the output elements and the differential carrier, this already a doubling of the blocking effect against a shaft-basket assembly is guaranteed. The arrangement with only one transmission gear a structural simple arrangement is guaranteed.

Preferably, the differential gear is designed as Planetenraddifferenzial and has as differential gears on planetary gears, which are in pairs with each other in meshing engagement. In each case a differential gear of the pairs of differential gears is available a ring gear of the differential carrier into engagement and the other differential gear of the respective pair of differential gears with the first output element in the form of a driven wheel. The differential gears are rotatably connected to the second output element in the form of a tarpaulin carrier.

The transmission gear can be designed as a planetary gear with a sun gear, planetary gears and a ring gear.

Here, the locking means may be designed as a multi-plate clutch with inner disks and outer lamellae, wherein the outer disk rotatably connected to the differential carrier and the inner disk to the sun gear as the first connection element of the transmission gear. The planet wheels of the transmission gear are rotatably supported by the first output element and rotatable. For this purpose, a planet carrier can serve as a second connecting element of the transmission gear, which is rotatably connected via a shaft toothing of an output shaft with the first output element. The second output element is rotatably connected to the ring gear as a third connection element of the transmission gear.

Alternatively, the locking means may be designed as a multi-plate clutch with inner disks and outer disks, the outer disks are firmly connected to the ring gear and the inner disk to the sun gear. The planet gears are held circumferentially with the first output element and the second output element is rotatably connected to the ring gear. Thus, a shaft-shaft arrangement is realized in which the speed difference between the inner plates and the outer plates is increased. Since the speed difference between the two output elements is twice as large as between one of the output elements and the differential carrier, this already ensures a doubling of the blocking effect with respect to a shaft-basket arrangement. Furthermore, a further increase in the speed difference is achieved in that the outer disks rotate with the second output element.

Further, the object is achieved by a differential gear for use in a vehicle a differential carrier rotatably mounted for rotation about a longitudinal axis, a first output element and a second output element, which are mounted coaxially in the differential carrier, differential gears rotatably mounted in the differential carrier, which carry a compensating movement

5 between the output elements allow

Locking means for generating a braking torque for speed equalization between the output elements and a transmission gear that translates the braking torque to a relative to this increased locking torque,

IO wherein a first connection element of the transmission gear is connected to the blocking means, a second connection element is connected to or formed by the first output element and a third connection element is connected to or formed by the differential carrier and wherein the blocking means are supported against the differential carrier,

15 solved.

Thus, a shaft-basket arrangement is ensured in which by means of a single transmission gear and thus a simple structure an increase in the locking torque is achieved

The differential gear can be designed as a bevel gear differential, in which the differential gears in the form of bevel gears are rotatably mounted coaxially in the differential carrier and at the same time are in meshing engagement with both drive elements in the form of output wheels.

> 5

The differential gear can also be designed as Kronenraddifferential, the differential gears are rotatably mounted in the form of spur gears in the differential carrier and are in meshing engagement with both output element in the form of crown wheels.

50

Even with these solutions, the transmission gear can be designed in the form of a planetary gear with a sun gear, planetary gears and a ring gear. Here, the locking means are preferably designed as a multi-plate clutch with inner disks and outer disks, the outer disks are rotatably connected to the differential carrier and the inner disk to the sun gear as the first connection element of the transmission gear. The first output element carries in this case the planet gears and thus acts as a planetary carrier of the planetary gear and thus represents the second connection element of the transmission. The differential carrier is rotatably connected to the ring gear as a third connection element of the transmission or forms this.

Preferred embodiments are explained below with reference to the drawings.

Herein shows

1 shows a longitudinal section of a differential cage in Planetenradbauweise,

Figure 2 is a longitudinal section of a differential cage in bevel gear design and

3 shows a longitudinal section of a differential cage in Kronenradbauweise.

Figure 1 shows a differential carrier 1, which has a first approach 2 and a second approach 3, which are arranged coaxially with each other. The differential carrier 1 is rotatably mounted on the lugs 2, 3 about a longitudinal axis L rotatably in a gear housing, not shown. Over the circumference, the differential carrier 1 has a flange portion 4, to which a not shown ring gear can be connected, via which the differential carrier 1 from the engine of a vehicle is driven in rotation.

A first output shaft 5 is inserted coaxially to the longitudinal axis L through a first bore 7 of the first lug 2 in the differential carrier 1 and slidably mounted in the first bore 7. A second output shaft 6 is inserted through a second bore 8 of the second projection 3 in the differential carrier 1 and slide-mounted in the second bore 8. In the output shafts 5, 6, it may be z. B. to side waves for Driving wheels of a vehicle act. The first output shaft 5 is connected to a free end located in the differential carrier 1 with a first output element in the form of a driven gear 9, wherein the output gear 9 is rotatably connected via a shaft toothing 10 with the first output shaft 5. The second output shaft 6 is connected at its located in the differential carrier 1 free end with a second output element in the form of a planet carrier 11, wherein a rotationally fixed connection is made by a shaft toothing 12. Trunnions 13 are connected to the planet carrier 11 and carry first differential gears 14 and second differential gears 15 which are axially parallel to the longitudinal axis L rotatably mounted on the pivot pin 13. The differential gears 14, 15 are each arranged in pairs, wherein in each case a first differential gear 14 with a ring gear 16 is in meshing engagement. The ring gear 16 is integrally formed by the differential carrier 1. Furthermore, the first differential gear 14 meshes with the respective second differential gear 15 of the differential gear pair. The second compensating wheel 15 is also in meshing engagement with the driven gear 9.

As a differential lock a multi-plate clutch 17 with inner plates 18 and outer plates 19 and a transmission gear in the form of a planetary gear 20 are provided. The planetary gear comprises a sun rim 21, planetary gears 22 and a ring gear 23.

The inner disks 18 of the multi-plate clutch 17 each have a bore 24 with a toothing, which engage in an outer toothing 25 of the sun gear 21, so that the inner disk 18 are rotatably mounted with the sun gear 21 and axially adjustable on this. The outer disks 19 have on their outer circumference teeth 26 which engage in rotation in corresponding grooves 27 which are incorporated in the differential carrier 1 and allow an axial adjustment of the outer disk 19 relative to the differential carrier 1. Axially, the blades 18, 19 are supported on the one hand against a support surface 28 of the differential carrier 1 and on the other hand against actuation elements 29. The actuators 29 are arranged axially displaceable axially parallel to the longitudinal axis L, wherein a ball ramp assembly 30 allows actuation via the actuating element 29 of the multi-plate clutch 17. The ball ramp arrangement consists of two arranged around the longitudinal axis L. te actuating rings 31, 32, each having a ball ramp 33, 34, which faces the respective other actuating ring 31, 32. Between the two actuating rings 31, 32 balls 35 are held in the ball ramps 33, 34, wherein the ball ramps 33, 34 are configured such that they axially approximate each other upon rotation of the actuation rings 31, 32, so that one of the actuating rings 31, the actuator 29 is acted upon axially and thus the multi-plate clutch 17 is actuated axially.

The sun gear 21 meshes with the planet gears 22, which are rotatably mounted on a planetary carrier 36 via pivot pins 37, which are arranged parallel to the longitudinal axis L. The planet carrier 36 is rotatably connected via a shaft teeth 38 with the first drive shaft 5. Further, the planetary gears mesh with the ring gear 23, which is arranged rotatably about the longitudinal axis L and rotatably connected to the second output element in the form of a planet carrier 11 is connected.

By operating the multi-plate clutch 17 in the event that a speed difference between the first output shaft 5 and the second output shaft 6 occurs, thus a locking torque between the two output shafts 5, 6 is generated. Here, the friction torque generated by the multi-plate clutch 17 is increased by means of the transmission gear 20 in a contrast increased locking torque between the two output shafts 5, 6. For further translation can be arranged between the multi-plate clutch 17 and output elements 9, 11 more planetary gear sets.

In an alternative embodiment can also be provided that the outer plates engage with their teeth in grooves of the sun gear, so that the multi-plate clutch 17 is not supported against the differential carrier 1 but against both output elements 9, 11.

Figure 2 shows a second embodiment in which the differential gear is formed in the form of a bevel gear differential. Components which correspond to components of the embodiment according to FIG. 1 are provided with reference symbols which are increased by the value 100. In contrast to the embodiment according to FIG. 1, the embodiment according to FIG. 2 has a first output element in the form of a first output gear 139 and a second output element in the form of a second output gear 140 a, uf. The first 5 driven gear 139 is rotatably connected by means of a shaft toothing 110 with the first output shaft 105. The second driven gear 140 is rotatably connected by means of a shaft toothing 112 with the second output shaft 106.

A pivot pin 113 is fixedly connected to the differential carrier 1 and arranged coaxially with respect to an axis of rotation D, which intersects the longitudinal axis L at right angles. On the pivot pin 113, a first differential gear 114 and a second differential gear, not shown, are rotatably supported, wherein both differential gears 114 are simultaneously in meshing engagement with the first output gear 139 and the second output gear 140. Thus, a compensating movement between the two driven I5 wheels 139, 140 and thus between the two output shafts 105, guaranteed.

The differential lock comprises the multi-plate clutch 117 and the transmission gear in the form of a planetary gear 120. Both components are formed as in the differential gear of Figure 1. The planet gears 122 of the planetary

.0 Drives 120 are rotatably connected to the first driven gear 139 via the pivots 137 and rotatable about the pivot pins 137, wherein the pivot pins 137 are arranged parallel to the longitudinal axis L. The first output gear 139 thus assumes the function of the planet carrier for the planetary gear 120. The planetary gears 122 mesh on the one hand with the sun edge 129, which on the first output shaft

15 105 is slidably mounted. Further, the planetary gears 122 mesh with a ring gear teeth 141, which is incorporated in an inner circumferential surface of the differential carrier 101.

Thus, upon actuation of the multi-plate clutch 117, the first output shaft 105 is braked relative to the differential cage 101 when a rotational speed difference occurs between the first output shaft 105 and the differential cage 101. It is thus a shaft-basket arrangement in which the first output shaft 105 is braked relative to the differential carrier 101. Through the transmission gear 120, an increase in the friction torque generated by the multi-plate clutch 117 is achieved to a higher locking torque between the differential cage 101 and the first output shaft 105. For further translation, additional planetary gears can be arranged between multi-disc clutch 117 and output elements 139, 140.

Figure 3 shows a third embodiment in which the differential gear is in the form of a crown gear differential. Components that correspond to components of the second embodiment according to Figure 2 are provided with reference numerals, which are increased by the value 100.

The differential gear is constructed comparable to the differential gear according to Figure 2 and differs only in that the differential gears 214 are designed in the form of spur gears which are rotatably mounted on pins 213 of a carrier 242. The carrier 242 is rotatably received in grooves 243 of the differential carrier 201. The driven wheels 239, 240 are designed as crown wheels, which are held in meshing engagement with the differential gears 214 (spur gears).

GKN Driveline International GmbH December 21, 2004

Main street 130 Mü / kin (20040469)

53797 Lohmar Q03071WO00

differential gear

LIST OF REFERENCE NUMBERS

1, 101,201 differential carrier

2, 102, 202 first approach

3, 103, 203 second projection 4, 104, 204 flange portion

5, 105, 205 first output shaft

6, 106, 206 second output shaft

7, 107, 207 first bore

8, 108, 208 second bore

9 output gear (first output element)

10, 110,210 shaft toothing

11 planet carrier (second output element)

12,112,212 shaft toothing

13,113,213 pivot

14, 114, 214 first balancing wheel

15 second balancing wheel

16 ring gear teeth

17, 117,217 multi-plate clutch

18, 118, 218 inner fins 19, 119,219 outer fins

20, 120, 220 planetary gearboxes

21,121,221 sun wheel

22,122,222 planetary gear 3 ring gear 4, 124, 224 bore 5, 125, 225 external toothing 6, 126, 226 tooth 7, 127, 227 groove 8, 128, 228 support surface 9, 129, 229 actuator 0, 130, 230 ball ramp assembly 1, 131, 231 actuation ring 2, 132, 232 actuating ring 3, 133, 233 ball ramp

34, 134, 234 ball ramp

35, 135, 235 ball

36 planet carriers

37, 137, 237 pivot

38 shaft toothing

139, 239 first output gear (first output element)

140, 240 second output gear (second output element)

141, 241 ring gear teeth

242 carriers

243 groove

L longitudinal axis

D rotation axis

Claims

Differential gear patent claims

Differential for use in a vehicle comprising a about a longitudinal axis (L) rotatably driven mounted differential carrier

(D. a first output element (9) and a second output element (11) coaxially in the differential carrier (1) are rotatably mounted in the differential carrier (1) rotatably mounted differential gears (14, 15), a compensating movement between the output elements (9 , 11), locking means (17) for generating a braking torque for speed equalization between the output elements (9, 11) and a transmission gear (20), which translates the braking torque to a relative to this increased locking torque, wherein a first connecting element (21) of the transmission gear (20) is connected to the blocking means (17), a second connecting element (36) is connected to or formed by the first output element (9) and a third connecting element (23) is connected to the second output element (11).

2. differential gear according to claim 1,

characterized,

that the differential gear is designed as a planetary gear differential, that the differential gears (14, 15) are designed as planetary gears, which are pairwise meshed with each other, a compensating wheel (14) of the pairs of differential gears is engaged with a ring gear toothing (16) of the differential carrier (1) and the other differential gear (15) of the respective differential pair is in engagement with the first output element in the form of a driven wheel (9); Balancing wheels (14, 15) are rotatably connected to the second output element in the form of a planetary carrier (11).

3. differential according to one of claims 1 or 2,

characterized,

that a planetary gear (20) with a sun gear (21), planetary gears (22) and a ring gear (23) is used as the transmission gear.

4. differential gear according to claim 3,

characterized,

in that the blocking means is designed as a multi-disc clutch (17) with inner disks (18) and outer disks (19), that the outer disks (19) are connected non-rotatably to the differential carrier (1), that the inner disks (18) are non-rotatable with the sun gear (21) are connected, that the planetary gears (22) of the transmission gear (20) with the first output element (9) are held circumferentially and that the second output element (11) with the ring gear (23) is rotatably connected.

5. differential according to claim 3,

characterized,

that the blocking means as a multi-disc clutch with inner disks and outer disks len is designed that the outer disks are rotatably connected to the ring gear, that the inner disks are rotatably connected to the sun gear, that the planetary gears of the transmission gear are rotatably held with the first output element and that the second output element is rotatably connected to the ring gear.

6. A differential gear for use in a vehicle comprising a differential carrier (101, 201) rotatably driven about a longitudinal axis (L), a first output element (139, 239) and a second output element (140, 240) mounted in the differential carrier (101, 201) are mounted in the differential carrier (101, 201) rotatably mounted differential gears (114, 214), which allow a compensating movement between the output elements (139, 140, 239, 240),

Locking means (117, 217) for generating a braking torque for Drehzahlangleichung between the output elements (139, 140, 239, 240) and a transmission gear (120, 220), which translates the braking torque to a relative to this increased locking torque, wherein a first Aήschlusselement (121, 212) of the transmission gear (120, 220) is connected to the blocking means (117, 217), a second connecting element (122, 222) is connected to or formed by the first output element (139, 239) and a third connecting element (141, 241) is connected to or formed by the differential cage (101, 201) and wherein the locking means (117, 217) are supported against the differential cage (101, 201).

7. differential according to claim 6,

characterized,

that the differential gear is designed as a bevel gear differential, that the differential gears (114) in the form of bevel gears in the differential carrier (101) are rotatably mounted and at the same time with two output element in the form of output gears (139, 140) are in meshing engagement.

8. differential gear according to claim 6,

characterized,

that the differential gear is designed as a crown gear differential, that the differential gears (214) are rotatably mounted in the form of spur gears in the differential carrier (201) and with two output element in the form of crown gears (239, 240) are in meshing engagement.

9. Differential gear according to one of claims 6 to 8,

characterized,

in that a planetary gear (120, 220) having a sun gear (121, 221), planet gears (122, 222) and a ring gear (141, 241) is used as the transmission gear.

10. differential gear according to claim 8,

characterized,

in that the blocking means are configured as a multi-disc clutch (117, 217) with inner disks (118, 218) and outer disks (119, 219) such that the outer disks (119, 219) are rotationally fixedly connected to the differential carrier (101, 201), that the inner disks (118, 218) are rotatably connected to the sun gear (121, 221), that the first output element (139, 239) carries the planet wheels (122, 222) and that the differential carrier (101, 201) is rotatably connected to or forms the ring gear (141, 241).