Supporting assembly for a lightweight differential

Abstract

A differential gearing for a motor vehicle, comprising a drive gear, by means of which torque can be introduced into the gearing, a first output element and a second output element, by means of which the torque can be output from the gearing, a differential housing attached to the drive gear in a rotationally fixed manner, wherein the drive gear and the differential housing together form a differential cage for transmitting torque from the drive gear to the first output element, wherein the first output element is arranged in such a way that the first output element can be rotated in relation to the differential cage, and a first rolling-element bearing for supporting the differential hosing on a housing, wherein a bearing shell of a second rolling-element bearing is directly attached to the drive gear in a rotationally fixed manner.

Claims

1. A differential transmission for a motor vehicle, comprising: a driving gear operatively arranged to introduce torque into the differential transmission; a first output member; a second output member; a differential housing non-rotatably connected to the driving gear, the differential housing and the driving gear forming a differential cage operatively arranged to: transmit torque from the driving gear to the first output member; and, rotate with respect to the first output member; a first rolling bearing for supporting the differential housing; and, a second rolling bearing including an outer ring, the driving gear non-rotatably connected to the outer ring.

2. The differential transmission recited in claim 1, wherein the driving gear is designed with a receptacle for receiving at least one component arranged to support a pinion gear.

3. The differential transmission recited in claim 2, wherein the receptacle is disposed in a radially inward extending flange section.

4. The differential transmission recited in claim 2, wherein the receptacle comprises a hole.

5. The differential transmission recited in claim 2, wherein the at least one component comprises a bolt, a pin, or a sleeve.

6. The differential transmission recited in claim 1, wherein outer ring is non-rotatably connected to the driving gear in a force fitting manner.

7. The differential transmission recited in claim 1, wherein the driving gear is pressed onto or into the outer ring in a force fitting manner.

8. The differential transmission recited in claim 1, wherein the outer ring is a solid component, which is produced by machining or extrusion.

9. The differential transmission recited in claim 1, wherein a support structure for the second output member is attached to the outer ring.

10. The differential transmission recited in claim 9, wherein the support structure for the second output member is pressed into or onto the outer ring.

11. The differential transmission recited in claim 1, wherein a support structure for the second output member is integrally formed with the outer ring.

12. The differential transmission recited in claim 1, wherein the differential transmission is designed as a planetary gear differential transmission.

13. The differential transmission recited in claim 1, wherein the differential transmission is designed as a spur gear differential transmission.

14. A differential transmission for a motor vehicle, comprising: a driving gear operatively arranged to introduce torque into the differential transmission; a first output member; a second output member; a differential housing non-rotatably connected to the driving gear, the differential housing and the driving gear forming a differential cage operatively arranged to: transmit torque from the driving gear to the first output member; and, rotate with respect to the first output member; a first rolling bearing for supporting the differential housing; a second rolling bearing including a bearing shell, the bearing shell non-rotatably connected to the driving gear; and, a support structure for the second output member connected to the bearing shell.

15. The differential transmission recited in claim 14, wherein the support structure for the second output member is pressed into or onto the bearing shell.

16. A differential transmission for a motor vehicle, comprising: a driving gear operatively arranged to introduce torque into the differential transmission; a first output member; a second output member; a differential housing non-rotatably connected to the driving gear, the differential housing and the driving gear forming a differential cage operatively arranged to: transmit torque from the driving gear to the first output member; and, rotate with respect to the first output member; a first rolling bearing for supporting the differential housing; a second rolling bearing including a bearing shell, the bearing shell non-rotatably connected to the driving gear; and, a support structure for the second output member integrally formed with the bearing shell.

Description

DESCRIPTION OF THE DRAWINGS

(1) Various embodiments are explained in greater detail below with reference to the drawings. The drawings show the following, in which:

(2) FIG. 1a is a longitudinal view of a first embodiment of a differential transmission;

(3) FIG. 1b is a longitudinal view of a first embodiment of a differential transmission;

(4) FIG. 2a is a longitudinal view of a second embodiment of a differential transmission;

(5) FIG. 2b is a longitudinal view of a second embodiment of a differential transmission;

(6) FIG. 3a is a longitudinal view of a third embodiment of a differential transmission; and,

(7) FIG. 3b is a longitudinal view of a third embodiment of a differential transmission.

(8) The figures are merely schematic in nature and serve only to elucidate the various embodiments. Identical elements are denoted by the same reference numerals. Details of the various embodiments may be combined.

DETAILED DESCRIPTION

(9) FIGS. 1a and 1b show inventive differential transmission 1 for a motor vehicle in a first embodiment. FIG. 2 shows a second embodiment; and FIGS. 3a and 3b show a third embodiment. The three embodiments are described in such a way that the same or equivalent details are described with reference to FIGS. 1a and 1b. Differing details are described with reference to the respective figure.

(10) Differential transmission 1 includes driving gear 2, output member in the form of sun gear 3, output member in the form of sun gear 4, differential housing 5 and several pairs of planet gears 13 and 14. Driving gear 2 and differential housing 5 are coupled to each other by means of riveted joints, which are not shown in the figures, in such a way that the driving gear and the differential housing are secured against rotation. The driving gear and the differential housing form together differential cage 10, which forms a planet carrier.

(11) Driving gear 2 has outer circumferential gear rim 20 and radially inwards adjoining flange section 16. Flange section 16 has bores 12, each of which forms a receptacle for bolt 15. Differential housing 5 also has bores 21, each of which forms a receptacle for corresponding bolt 15. In other words, bolt 15 is received on one side in bore 12 of driving gear 2 and on the opposite side in bore 21 of differential housing 5.

(12) Differential cage 10, composed of driving gear 2 and differential housing 5, is mounted by means of rolling bearing 6 and rolling bearing 11.

(13) Rolling bearing 6 is used to mount differential housing 5 on an attachment (not shown in the figures) to a motor vehicle, for example, to a housing or a flange. Rolling bearing 11 is used to mount driving gear 2 on an attachment to a motor vehicle, for example, to a housing or a flange. Rolling bearing 6 and rolling bearing 11 are placed in an O-type arrangement and are designed in each instance as angular contact ball bearings with rolling bodies 9.

(14) In contrast to planet gear 13, planet gear 14 has a longer axial length. The axial length is measured along the axis of rotation of differential transmission 1. In the figures only planet gear 13 of planet gears 13 and 14 of differential transmission 1 is shown in its entirety; of planet gear 14, only a part of the teeth can be seen, because the teeth are covered for the most part by planet gear 13. Sun gear 3 meshes with planet gear 13; and other sun gear 4 meshes with planet gear 14. Planet gears 13 and 14 of pair of planet gears also mesh with each other.

(15) Planet gear 13 is mounted on bolt 15. Bolt 15 is disposed in sleeves (not shown in the figures), which are hardened, in particular, fully hardened, in driving gear 2 or more specifically in differential housing 5. The sleeves have radially projecting flanges, which rest against planet gear 13 and determine its axial position. Planet gear 14 may be mounted accordingly.

(16) The two sun gears 3 and 4 have internal tooth system 29, by means of which the torque can be transmitted on transmitting elements, which are not shown in the figures, to the wheels of a motor vehicle. Friction disk (friction ring) 28 is disposed between the two sun gears 3 and 4.

(17) It should be noted that the tip circle diameters of the two sun gears 3 and 4 are different. In this case the tip circle diameter of large sun gear 4 is larger than the root circle diameter of small sun gear 3. Large sun gear 4 is approximately 20% larger than small sun gear 3. In traction mode, the smaller planet gear of pair of planet gears 13, 14 runs ahead of the large planet gear. The solution reduces the noise emission. Any problems arising with respect to the support width are also reduced. Even limited slip values of up to 30% can be achieved without any major problems. In this way it is possible to generate a so-called Torsen differential.

(18) In the exemplary embodiment that is shown, differential housing 5 is a sheet metal component. The differential housing has a shape that is more or less L shaped in the cross section. Furthermore, the differential housing has leg 22 extending in the radial direction and leg 23 extending in the axial direction. Differential housing 5, which is designed as a sheet metal component in the exemplary embodiments shown here, may also be made as a cast or forged part.

(19) Rolling bearing 6 comprises inner ring 8 and outer ring 7, between which rolling bodies 9 roll.

(20) Outer ring 7 is a sheet metal component, which is produced by means of cold forming, and is disposed on differential housing 5 in a rotationally fixed manner. Outer ring 7 has base section 31, which extends in the radial direction, rests against leg 23 and supports this leg in the radial direction. At base section 31, arm 24 is arranged radially inwards; and arm 25 is arranged radially outwards. Arm 25 extends in the axial direction, rests against leg 22 of differential housing 5, and supports the leg in the radial direction. Arm 25 extends more or less in the axial direction and forms a raceway for rolling bodies 9.

(21) Inner ring 8 is a solid bearing ring and also forms a bearing surface for rolling bodies 9.

(22) Rolling bearing 11 has bearing shell 18 as inner ring 18 and bearing shell 19 as outer ring 19, between which rolling bodies 9 roll.

(23) In the embodiments of FIGS. 1a and 1b and FIGS. 2a and 2b, outer ring 19 is a solid bearing ring, which is produced by machining. The outer ring has externally offset 17. Outer ring 19 is attached directly to driving gear 2, and specifically to inside edge 27 of flange section 16. It is held, in particular, is pressed in, in a force fitting manner. Offset 17 enables an axial guide and alignment of driving gear 2. At the inside diameter of outer ring 19 support structure 26 for sun gear 4 is arranged and supported in the radial and axial direction. This arrangement is achieved by means of offset 30. Support structure 26 supports sun gear 4 in both the axial direction and the radial direction. In the embodiments shown in FIGS. 1a through 2b, support sleeve 26 is a sheet metal component and has a wall of constant thickness.

(24) In the embodiment according to FIGS. 1a and 1b, inner ring 18 is a solid bearing ring, which is produced by machining. The inner ring is pressed into flange 32 of a housing for the purpose of attaching to a motor vehicle and has on its outer periphery offset 33, which serves an axial alignment. Pilot bearing 34 is incorporated into the inner periphery of inner ring 18, for additional support of sun gear 4, where in this case the outer raceway of pilot bearing 34 is formed by the inner periphery of inner ring 18. In addition, shaft sealing ring 35 is also pressed into inner ring 18.

(25) In the embodiment according to FIGS. 2a and 2b, inner ring 18 is pressed onto flange 32 of a housing for the purpose of attaching to a motor vehicle. Pilot bearing 34 is pressed into flange 32 for additional support of sun gear 4.

(26) In the embodiment according to FIGS. 3a and 3b, outer ring 19 of rolling bearing 11 is a sheet metal component, which is produced by cold forming. Outer ring 19 is pressed into circumferential inside edge 27 of flange area 16 of driving gear 2 in a rotationally fixed manner and is positioned above it in the axial direction. The outer ring rests together with a top surface of base section 36 against flange section 16 in the axial direction, with the effect that the outer ring is positioned in the axial direction. Inner ring 18 of rolling bearing 11 is designed as a solid bearing ring.

(27) Outer ring 19 is constructed in one piece with support sleeve 26. Base section 36, which extends in the radial direction, is followed radially inwards by integral support sleeve 26, which is formed essentially in the shape of a U, and which is used to support sun gear 4 in the radial and axial direction. Arm 37 extends radially outwards from base section 36; and the arm forms an outer raceway for rolling bodies 9 of rolling bearing 11.

(28) In all of the embodiments the surface of support sleeves 26 that faces sun gear 3 and 4, respectively, forms a bearing surface, on which respective sun gear 3, 4 is slidably mounted and relative to which the respective sun gear rotates.

LIST OF REFERENCE NUMERALS

(29) 1 differential transmission

(30) 2 driving gear

(31) 3 output member, sun gear

(32) 4 output member, sun gear

(33) 5 differential housing

(34) 6 first rolling bearing

(35) 7 outer ring

(36) 8 inner ring

(37) 9 rolling body

(38) 10 differential cage

(39) 11 second rolling bearing

(40) 12 receptacle

(41) 13 first planet gear

(42) 14 second planet gear

(43) 15 component, bolt

(44) 16 flange section

(45) 17 offset

(46) 18 bearing shell, inner ring

(47) 19 bearing shell, outer ring

(48) 20 gear rim

(49) 21 bore

(50) 22 leg

(51) 23 leg

(52) 24 arm

(53) 25 arm

(54) 26 support structure, support sleeve

(55) 27 inside edge

(56) 28 friction disk

(57) 29 internal teeth

(58) 30 offset

(59) 31 base section

(60) 32 flange

(61) 33 offset

(62) 34 pilot bearing

(63) 35 shaft sealing ring

(64) 36 base section

(65) 37 arm