Differential Transmission for a Vehicle

Abstract

A differential transmission for a vehicle includes a first output shaft, a second output shaft, a first planetary gearset, a second planetary gearset, a sun ring gear, and a stationary component. A first planet carrier of the first planetary gearset is connected with the first output shaft by a torque-proof connection. A second ring gear of the second planetary gearset is torque-proofly connected with the second output shaft. The sun ring gear forms a first ring gear of the first planetary gearset at an inner circumference and a second sun gear of the second planetary gearset at an outer circumference. A second planet carrier of the second planetary gearset is supported at the stationary component. A first planet carrier of the first planetary gearset is rotatably supported at the stationary component by a support. The support of the first planet carrier is arranged opposite the torque-proof connection in an axial direction with respect to a first planet gear.

Claims

1-15. (canceled)

16. A differential transmission (3) for a vehicle, comprising: a first output shaft (5); a second output shaft (6); a first planetary gearset (10) comprising a first sun gear (11), a first planet carrier (12), a first planet gear (13), and a first ring gear (14), the first sun gear (11) engaged with the first planet gear (13), the first planet gear (13) engaged with the first ring gear (14), the first planet carrier (12) connected with the first output shaft (5) by a torque-proof connection (30); a second planetary gearset (20) comprising a second sun gear (21), a second planet carrier (22), a second planet gear (23), and a second ring gear (24), the second sun gear (21) engaged with the second planet gear (23), the second planet gear (23) is engaged with the second ring gear (24), the second ring gear (24) connected with the second output shaft (6); a sun ring gear (32) forming the first ring gear (14) at an inner circumference and the second sun gear (21) at an outer circumference; and a stationary component (31), wherein the second planet carrier (22) is supported at the stationary component (31), and the first planet carrier (12) is rotatably supported at the stationary component (31) by a support (40), and wherein the support (40) of the first planet carrier (12) is arranged opposite the torque-proof connection (30) in an axial direction with respect to the first planet gear (13).

17. The differential transmission (3) of claim 16, wherein the support (40) of the first planet carrier (12) is supported at a cylindrical outer circumference of a section of the stationary component (31).

18. The differential transmission (3) of claim 16, wherein the support (40) of the first planet carrier (12) is supported at a cylindrical inner circumference of a section of the stationary component (31).

19. The differential transmission (3) of claim 16, further comprising an input element (4) torque-proofly connected to the first sun gear (11) and rotatably supported at the stationary component (31) by an additional support (43).

20. The differential transmission (3) of claim 19, wherein the support (40) of the first planet carrier (12) is arranged outside the additional support (43) of the input element (4) in a radial direction.

21. The differential transmission (3) of claim 19, wherein the support (40) of the first planet carrier (12) overlaps the additional support (43) of the input element (4) in the axial direction.

22. The differential transmission (3) of claim 19, wherein the support (40) of the first planet carrier (12) is arranged next to the additional support (43) of the input element (4) in the axial direction.

23. The differential transmission (3) of claim 16, wherein the first sun gear (11) is hollow, and the first output shaft (5) extends through the first sun gear (11) and coaxially to the first sun gear (11).

24. The differential transmission (3) of claim 23, wherein: an input element (4) is torque-proofly connected to the first sun gear (11) and rotatably supported at the stationary component (31) by an additional support (43); the input element (4) is configured as a hollow shaft; and the first output shaft (5) extends through the input element (4).

25. The differential transmission (3) of claim 23, wherein: an input element (4) is torque-proofly connected to the first sun gear (11) and rotatably supported at the stationary component (31) by an additional support (43); and the input element (4) and the first sun gear (11) as one piece.

26. The differential transmission (3) of claim 16, wherein: the sun gear (32) is ring-shaped; the first ring gear (14) is arranged radially inside the second sun gear (21); and the first ring gear (14) overlaps the second sun gear (21) in the axial direction.

27. The differential transmission (3) of claim 16, wherein the second output shaft (6) is arranged coaxially to the first output shaft (5) and opposite the first output shaft (5) in the axial direction.

28. The differential transmission (3) of claim 16, wherein a torque introduced into the first sun gear (11) is transmittable to the first output shaft (5) and to the second output shaft (6).

29. A drive unit (2), comprising: a motor (73); and the differential transmission (3) of claim 16, wherein the motor (73) is coupled to the differential transmission (3) in order to drive the first sun gear (11).

30. A vehicle, comprising: the drive unit (2) of claim 29; and drive wheels (71), wherein the drive unit (2) is mounted in the vehicle (1) in order to drive the drive wheels (71).

Description

BRIEF DESCRIPTION OF FIGURES

[0035] FIG. 1 shows a top view of a vehicle according to an embodiment.

[0036] FIG. 2 shows a sectional view of a differential transmission for a vehicle according to an embodiment.

[0037] FIG. 3 shows a sectional view of a differential transmission for a vehicle according to an alternative embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

[0038] FIG. 1 shows a top view of a vehicle 1 according to an embodiment. The vehicle 1 comprises a drive unit 2 having a motor 73, a differential transmission 3 having a first output shaft 5 and a second output shaft 6, drive wheels 70, a first axle 71 and a second axle 72. The motor 73 is an electric motor in the present embodiment. In an alternative embodiment, the drive unit 2 is an internal combustion engine. The motor 73 is connected with the differential transmission 3 in such a way that the motor 73 may drive the first output shaft 5 and the second output shaft 6 by means of the differential transmission 3 and divide its driving power.

[0039] The first output shaft 5 and the second output shaft 6 extend from the differential transmission 3 in opposite directions parallel to that of the first axle 71 towards the drive wheels 70. The first output shaft 5 extends through the transmission 3 and the motor 73. The first axle 71 is a driven rear axle of the vehicle 1 in the present case. In an alternative embodiment, the first axle 71 may be a driven front axle of the vehicle 1. The first output shaft 5 and the second output shaft 6 are connected with the drive wheels 70 of the vehicle 1 in such a way that the first output shaft 5 and the second output shaft 6 may each drive one of the drive wheels 70.

[0040] One of the drive wheels 70 transmits a driving power of the motor 73 to a ground on which the drive wheels 70 rest and generates a travelling motion of the vehicle 1. Steerable wheels 74 of the vehicle 1 are rotatably arranged on a second axle 72, in the present case a front axle. In an alternative embodiment, the second axle 72 may be a rear axle of the vehicle 1.

[0041] In a further embodiment, joints and wheel hubs may be arranged between the respective drive wheels 70 and the first output shaft 5 and the second output shaft 6 in order to compensate for possible misalignments of the first output shaft 5 and the second output shaft 6, respectively.

[0042] FIG. 2 shows a sectional view of a differential transmission 3 for a vehicle 1 according to an embodiment. FIG. 2 is a half-section showing an upper part of the differential transmission 3. The differential transmission 3 comprises a stationary component 31, an input shaft 4, a first output shaft 5 and a second output shaft 6. The first output shaft 5 and the second output shaft 6 extend out of the stationary component 31 in opposite directions. The differential transmission 3 further comprises a first planetary gearset 10 having a first sun gear 11, a first planet carrier 12, a number of first planet gears 13 and a first ring gear 14. The first planet gears 13 are each rotatably mounted by means of a first planet axis. The first planet carrier 12 is mounted in the stationary component 31 by means of a support 40. The first sun gear 11 is in engagement with the first planet gears 13. The first planet gears 13 are in engagement with the first ring gear 14. The differential transmission 3 further comprises a second planetary gearset 20 having a second sun gear 21, a second planet carrier 22, a number of second planet gears 23 and a second ring gear 24. The second planet gears 23 are each rotatably mounted by means of a second planet axis. The second sun gear 21 is in engagement with the second planet gears 23. The second planet gears 23 are in engagement with the second ring gear 24. The first sun gear 11, the first planet gears 13, the first ring gear 14, the second sun gear 21, the second planet gears 23 and the second ring gear 24 overlap in the axial direction.

[0043] The support 40 of the first planet carrier 12 is described in more detail below.

[0044] The support 40 of the first planet carrier 12 is arranged in the axial direction opposite a torque-proof connection 30 of the first planet carrier 12 with the first output shaft 5 with respect to the first planet gears 13 of the first planetary gearset 10. The first planet carrier 12 is thus supported on both sides in the axial direction with respect to the first planet gears 13. A radial force from one of the first planet gears 13 can thus be distributed to the support 40 of the first planet carrier 12 and the torque-proof connection 30. This leads to a more uniform force distribution in the first planet carrier 12.

[0045] The support 40 of the first planet carrier 12 is designed here as a needle sleeve without an inner ring. The support 40 of the first planet carrier 12 further comprises a bushing 44, here a hardened steel sleeve. The bushing 44 is arranged radially inside the needle sleeve. Needles of the needle sleeve can thus roll on the bushing 44. In this case, the bushing 44 is positioned such that it projects beyond the needle sleeve in the axial direction. The width of the bushing 44 in the axial direction is greater than the width of the needle sleeve.

[0046] The differential transmission 3 further comprises an input element 4. The input element 4 is rotatably supported at the stationary component 31 by means of a support 43.

[0047] The support 40 of the first planet carrier 12 overlaps the support 43 of the input element 4 in the axial direction. In this case, the support 40 of the first planet carrier 12 is arranged outside the support 43 of the input element 4 in the radial direction. In other words, the support 40 of the first planet carrier 12 is arranged above the support 43 of the input element 4 in the sectional view in FIG. 2. A compact installation space of the differential transmission 3 in the axial direction can thus be achieved.

[0048] Further details of the embodiment are described below.

[0049] The input element 4 is formed as a hollow shaft. The input element 4 can rotate about its central axis. The input element 4 is torque-proofly connected with a rotor shaft of the motor 73 and is driven therewith. The rotor shaft of the motor is not shown in FIG. 2. The first sun gear 11 is hollow and formed in one piece with the input element 4. The first output shaft 5 extends through the first sun gear 11 and the input element 4 and is coaxial to the first sun gear 11.

[0050] The differential transmission 6 comprises a sun ring gear 32. The sun ring gear 32 is hollow and ring-shaped. The sun ring gear 32 forms the first ring gear 14 at an inner circumference and the second sun gear 21 at an outer circumference. The sun ring gear 32 is arranged radially outside the first planet gears 13. The sun ring gear 32 is simultaneously in engagement with the first planet gears 13 and the second planet gears 23.

[0051] The second planet carrier 22 is supported at the stationary component 31 in a torque-proof manner in that the second planet carrier 22 is fastened to the stationary component 31 in the axial direction. The second ring gear 24 is torque-proofly connected with the second output shaft 6. The first output shaft 5 and the second output shaft 6 are coaxial to one another and rotatably supported in the stationary component 31.

[0052] In a further embodiment, which comprises all the features of the preceding embodiment, the stationary component 31 is a two-part transmission housing. A section of a first part of the two-part transmission housing is shown in FIG. 2 on the left side of the differential transmission 3. A section of a second part of the two-part transmission housing is shown in FIG. 2 on the right side of the differential transmission 3. The two parts of the two-part transmission housing are circumferentially connected with one another by means of screw connections. The screw connections are not shown in FIG. 2.

[0053] The support 40 of the first planet carrier 12 forms a floating bearing. The support 43 of the input element 4 is in the present case a grooved ball bearing and forms a fixed bearing.

[0054] The first output shaft 5 is rotatably supported in the stationary component 31 by means of a support, which is not shown. The support of the first output shaft 5, here a grooved ball bearing, is designed as a fixed bearing.

[0055] The second output shaft 6 is rotatably supported at the stationary component 31 by means of a first support 41 and a second support 42. The first support 41 of the second output shaft 6, here a needle bearing, is a floating bearing. The second support 42 of the second output shaft 6, here a grooved ball bearing, is a fixed bearing. In an alternative embodiment, the first support 41 is designed as a fixed bearing and the second support 42 is designed as a floating bearing.

[0056] In a further embodiment, which comprises all the features of the preceding embodiment, the width of the first sun gear 11 in the axial direction is greater than the width of the first planet gears 13. Furthermore, the width of the sun ring gear 32 in the axial direction is greater than the width of the first planet gears 13 and the second planet gears 23, respectively. Furthermore, for positioning the sun ring gear 32 relative to the first planet gears 13 in the axial direction, securing elements 56, 57, here snap rings, and thrust washers are provided at an inner circumference of the sun ring gear 32 on both sides of the first planet gears 13.

[0057] An outer ring of the needle sleeve of the support 40 of the first planet carrier 12 is positioned in the axial direction by means of a shoulder of the first planet carrier 12 and a securing element 50, here a snap ring. The bushing 44 is positioned in the axial direction by means of a shoulder of the stationary component 31 and a securing element 51, here a securing ring.

[0058] An outer ring of the first support 41 of the second output shaft is positioned in the axial direction by means of a shoulder in the stationary component 31 and by means of a securing element 53, here a snap ring. An outer ring of the second support 42 is positioned in the axial direction by means of a shoulder in the stationary component 31 and by means of a securing element 58, here a snap ring. An inner ring of the second support 42 is positioned in the axial direction by means of a shoulder in the second output shaft 6 and by means of a securing element 54, here a snap ring.

[0059] The width of the second ring gear 24 is greater than the width of the second planet gears 23. For the torque-proof connection of the second ring gear 24 to the second output shaft 6, the second ring gear 24 and the second output shaft 6 each comprise a toothing of a shaft-hub connection. Furthermore, the torque-proof connection comprises a securing element 55, here a snap ring, for relative positioning in the axial direction.

[0060] The torque-proof connection 30 of the first planet carrier 12 with the first output shaft 5 comprises a securing element 52, here a snap ring, for axial relative positioning. In the present embodiment, the input element 4 is formed in one piece with the rotor shaft and is rotatably supported in the stationary component 31 via a rotor support. In an alternative embodiment, the input element 4 comprises a toothing for a shaft-hub connection for a torque-proof connection of the input element 4 to the rotor shaft.

[0061] FIG. 3 shows a sectional view of a differential transmission 3 for a vehicle 1 according to an alternative embodiment of the present invention. The present embodiment differs from the preceding embodiments in that the support 40 of the first planet carrier 12 is designed differently than in the preceding embodiments. All other features are identical to the previously described embodiments.

[0062] The support 40 of the first planet carrier 12 is arranged next to the support 43 of the input element 4 in the axial direction. The support 40 of the first planet carrier 12 is arranged inside the support 43 of the input element in the radial direction. The bushing 44 of the support 40 of the first planet carrier 12 may be dispensed with here, since the first planet carrier 12 is produced at least in regions from hardened steel. In an alternative embodiment, the first planet carrier 12 is produced from aluminum. The bushing 44 is then provided at an outer circumference of a section of the first planet carrier 12.

[0063] In a further embodiment, the outer ring of the support 40 of the first planet carrier 12 is positioned in the axial direction by means of a shoulder of the stationary component 31 and a securing ring 50, here a snap ring.

REFERENCE SIGNS

[0064] 1 vehicle [0065] 2 drive unit [0066] 3 differential transmission [0067] 4 input element [0068] 5 first output shaft [0069] 6 second output shaft [0070] 10 first planetary gearset [0071] 11 first sun gear of the first planetary gearset [0072] 12 first planet carrier of the first planetary gearset [0073] 13 first planet gear of the first planetary gearset [0074] 14 first ring gear of the first planetary gearset [0075] 20 second planetary gearset [0076] 21 second sun gear of the second planetary gearset [0077] 22 second planet carrier of the second planetary gearset [0078] 23 second planet gear of the second planetary gearset [0079] 24 second ring gear of the second planetary gearset [0080] 30 torque-proof connection [0081] 31 stationary component [0082] 32 sun gear [0083] 40 support of the first planet carrier [0084] 41 first support of the second output shaft [0085] 42 second support of the second output shaft [0086] 43 support of the input element [0087] 44 bushing [0088] 50, 51, 52, 53, 54, 55, 56, 57, 58 securing element [0089] 70 drive wheel [0090] 71 first axle [0091] 72 second axle [0092] 73 motor [0093] 74 steerable wheel