HUB ARRANGEMENT FOR TWIN WHEELS

Abstract

A hub arrangement for twin wheels comprises a stationary carrier; an intermediate hub which is rotatable about an axis of rotation and which can be driven by a drive shaft; a differential gear having an input which is connected to the intermediate hub; a first wheel hub which is connected to a first output of the differential gear; and a second wheel hub which is connected to a second output of the differential gear. The hub arrangement furthermore comprises a first braking apparatus which is effective between the stationary carrier and the intermediate hub and a second braking apparatus which is effective between the stationary carrier and the second wheel hub or between the intermediate hub and the second wheel hub. In this respect, the first braking apparatus and the second braking apparatus can be actuated separately from one another.

Claims

1. A hub arrangement (11) for twin wheels, comprising a stationary carrier (15); an intermediate hub (19) which is rotatable about an axis of rotation (D) and which can be driven by a drive shaft (13); a differential gear (39) having an input (41) which is connected to the intermediate hub (19); a first wheel hub (31) which is connected to a first output (43) of the differential gear (39); a second wheel hub (33) which is connected to a second output (43) of the differential gear (39); a first braking apparatus (45) which is effective between the stationary carrier (15) and the intermediate hub (19); and a second braking apparatus (47) which is effective between the stationary carrier (15) and the second wheel hub (33) or between the intermediate hub (19) and the second wheel hub (33), wherein the first braking apparatus (31) and the second braking apparatus (33) can be actuated separately from one another.

2. A hub arrangement in accordance with claim 1, wherein the first wheel hub (31) and the second wheel hub (33) are arranged coaxially to one another.

3. A hub arrangement in accordance with claim 1, wherein the differential gear (39) is configured as a bevel differential.

4. A hub arrangement in accordance with claim 1, wherein the intermediate hub (19) is rotatably supported at the stationary carrier (15).

5. A hub arrangement in accordance with claim 1, further comprising a reduction gear (17), wherein the intermediate hub (19) is driven by the drive shaft (13) via the reduction gear (17).

6. A hub arrangement in accordance with claim 1, wherein at least one of the first wheel hub (31) and the second wheel hub (33) is rotatably supported at the intermediate hub (19).

7. A hub arrangement in accordance with claim 1, wherein the first wheel hub (31) is rotatably supported at the intermediate hub (19) and the second wheel hub (33) is rotatably supported at the first wheel hub (31).

8. A hub arrangement in accordance with claim 1, wherein the second wheel hub (33) is rotatably supported at the intermediate hub (19) and the first wheel hub (31) is rotatably supported at the second wheel hub (33).

9. A hub arrangement in accordance with claim 1, wherein the first braking apparatus (45) has an axially movable first piston (49) supported at the stationary carrier (15); and wherein the second braking apparatus (47) has an axially movable second piston (49) supported at the stationary carrier (15).

10. A hub arrangement in accordance with claim 1, wherein the first braking apparatus (45) and the second braking apparatus (47) are arranged axially offset from one another with respect to the axis of rotation (D).

11. A hub arrangement in accordance with claim 1, wherein the first braking apparatus (45) and the second braking apparatus (47) are arranged radially offset from one another with respect to the axis of rotation (D).

12. A hub arrangement in accordance with claim 1, wherein the first braking apparatus (45) comprises a disk pack (51) associated with the stationary carrier (15) and a disk pack (53) cooperating therewith and associated with the intermediate hub (19), with the disk pack (51) associated with the stationary carrier (15) engaging into the disk pack (53) associated with the intermediate hub (19) radially from the outside or radially from the inside with respect to the axis of rotation (D).

13. A hub arrangement in accordance with claim 1, wherein the second braking apparatus (47) comprises a disk pack (55) associated with the stationary carrier (15) or with the intermediate hub (19) and a disk pack (57) cooperating therewith and associated with the second wheel hub (33), with the disk pack (33) associated with the stationary carrier (15) or with the intermediate hub (19) engaging into the disk pack (57) associated with the second intermediate hub (33) radially from the outside or radially from the inside with respect to the axis of rotation (D).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention will be described in more detail in the following with reference to the Figures.

[0018] FIGS. 1 to 6 show in a schematic representation in each case different embodiments of hub arrangements in accordance with the invention which substantially differ from one another by the relative arrangement of the two braking apparatus with respect to one another, by the direction of engagement of respective disk packs of the braking apparatus, and/or by the respective arrangement of the second braking apparatus between the stationary carrier and the second wheel hub or between the intermediate hub and the second wheel hub.

[0019] Mutually corresponding elements of the different embodiments are marked by the same respective reference numeral in the Figures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] It is common to all the FIGS. 1 to 6 that only an upper half of the embodiment of a hub arrangement 11 in accordance with the invention shown therein is shown in a very simplified schematic sectional representation. The section in this respect extends radially with respect to and starting from an axis of rotation D with respect to which the hub arrangement 11 is configured substantially rotationally symmetrically. Only one (namely the left hand) axis side is shown; at the other side, the respective vehicle axle has a corresponding hub arrangement 11 in a specular symmetrical design.

[0021] The hub arrangement 11 respectively comprises a drive shaft 13 which can be driven by an engine (not shown), for example via an axial differential (likewise not shown) to make a rotation about the axis of rotation D. The drive shaft 13 is arranged within a stationary carrier 15 configured as an axial funnel and is drive-effectively connected to a reduction gear 17 via which the drive shaft 13 can drive an intermediate hub 19 to make a rotation about the axis of rotation D. The intermediate hub 19 is in this respect rotatably supported via bearing apparatus 21 at the stationary carrier 15.

[0022] The reduction gear 17 is configured as a planetary transmission and comprises a sun gear 23 which is rotationally fixedly connected to the drive shaft 13. An annulus gear 25 of the planetary transmission is coupled to the stationary carrier 15 and is thereby likewise stationary. Planetary gears 27, of which only one is shown and which are supported at a planet carrier 29, mesh with the sun gear 23 and with the annulus gear 25. The planet carrier 29 in this respect forms the output of the reduction gear 1 and is connected to the intermediate hub 19 for a common rotation.

[0023] The hub arrangement 11 furthermore comprises a first wheel hub 31 and a second wheel hub 33 which are both respectively supported at the intermediate hub 19 rotatable about the axis of rotation D, wherein bearing apparatus 35 and 37 are respectively provided for the radial and axial support. To distribute the drive torque transmitted onto the intermediate hub 19 by the drive shaft 13 over the two wheel hubs 31, 33, a differential gear 39 is provided which is configured, for example, as a bevel differential. In this respect, an input 41 of the differential gear 39 is fixedly connected to the intermediate hub 19. The input 41 can in particular have spigots which are aligned radially to the axis of rotation D and at which a respective compensation bevel gear is rotatably supported. Two further bevel gears which mesh with the compensation bevel gears form outputs 43, 43 of the differential gear 39 and are fixedly connected to a respective one of the wheel hubs 31, 33 for a common rotation. In this manner, the differential gear 39 allows the transmission of drive torque from the intermediate hub 19 to the two wheel hubs 31, 33, wherein a relative movement of the wheel hubs 31, 33 relative to one another is permitted, whereby wear and slip are in particular avoided during cornering.

[0024] The design of the hub arrangement 11 shown with a drive shaft 13 guided in the stationary carrier 15, with an intermediate hub 19 supported at the stationary carrier 15 and with wheel hubs 31, 33 supported at the intermediate hub 19, all of them being arranged coaxially to one another, allows a particularly compact design of the hub arrangement 11 which is in particular especially important with wheel drives for twin wheels.

[0025] For the active braking of both wheel hubs 31, 33, the hub arrangement 11 furthermore comprises a first braking apparatus 45 and a second braking apparatus 47 which are configured separately from one another in the manner of multiple-disk clutches and which are also actuable separately from one another. In this respect, the two braking apparatus 45, 47 each comprise disk packs 51, 53 and 55, 57 respectively as well as a respective movable piston 49 and 49 which are supported at the stationary carrier 15 axially to the axis of rotation D and by means of which the disks of the two respective disk packs 51, 53 or 55, 57 respectively can be brought into contact with one another to brake a movement of the two respective disk packs 51, 53 or 55, 57 respectively relatively to one another, optionally up to a frictionally engaging, rigid connection of the two disk packs 51, 53 or 55, 57 respectively to one another.

[0026] In all the hub arrangements 11 shown in FIGS. 1 to 6, the first braking apparatus 45 is effective between the stationary carrier 15 and the intermediate hub 19. In the embodiments in accordance with FIGS. 1 to 4, the second braking apparatus 47 is in this respect effective between the stationary carrier 15 and the second wheel hub 33, whereas in the embodiments in accordance with FIGS. 5 and 6, the second braking apparatus 47 is effective between the intermediate hub 19 and the second wheel hub 33. In these last-named cases, the second wheel hub 33 is consequently indirectly braked via the intermediate hub 19 at the stationary carrier 15.

[0027] The embodiments shown in the Figures furthermore differ with respect to the relative arrangement of the two braking apparatus 45, 47 with respect to one another. In the embodiments in accordance with FIGS. 1, 3, and 5, the respective first braking apparatus 45 and the second braking apparatus 47 are arranged axially offset from one another with respect to the axis of rotation D. This in particular allows a design which only takes up a small construction space in the radial direction and in which advantageously identical parts can be used for the pistons 49, 49 and for the disk packs 51, 55 or 55, 57 respectively for both braking apparatus 45, 47. In the embodiments in accordance with FIGS. 2, 4, and 6, in contrast, the first braking apparatus 45 and the second braking apparatus 47 are arranged radially offset from one another with respect to the axis of rotation D. In this manner, a particularly small axial construction width can be implemented, which can be advantageous in dependence on the planned application, in particular with short axles.

[0028] A further difference between the hub arrangements 11 shown in the different Figures results from the alignment of the respective disk packs 51, 55 or 55, 57 respectively of the braking apparatus 45, 47. In this respect, in the embodiments of FIGS. 1, 2, 5 and 6, the disk pack 51 of the first braking apparatus 45 associated with the stationary carrier 15 engages radially from the outside with respect to the axis of rotation D into the disk pack 53 of the first braking apparatus 45 associated with the intermediate hub 19, whereas in the embodiments of FIGS. 3 and 4, actually conversely, the disk pack 51 associated with the stationary carrier 15 engages radially from the inside into the disk pack 53 associated with the intermediate hub 19.

[0029] With respect to the second braking apparatus 47. FIGS. 1 and 2 show embodiments in which the disk pack 55 of the second braking apparatus 47 associated with the stationary carrier 15 respectively engages into the disk pack 57 associated with the second wheel hub 33 radially from the outside with respect to the axis of rotation D. In contrast, in the embodiments of FIGS. 3 and 4, actually conversely, the disk pack 55 of the second braking apparatus 47 associated with the stationary carrier 15 engages into the disk pack 57 of the second braking apparatus 47 associated with the second wheel hub 33 radially from the inside with respect to the axis of rotation D.

[0030] In a manner corresponding hereto, in the embodiments in accordance with FIGS. 5 and 6, the disk pack 55 of the second braking apparatus 47 associated with the intermediate hub 19 engages into the disk pack 57 of the second braking apparatus 47 radially from the inside with respect to the axis of rotation D. It is generally correspondingly possible that the mutual engagement of the respective disk packs 55, 57 takes place exactly conversely with respect to the radial alignment to the axis of rotation D.

[0031] In addition, further embodiments can be implemented in which a described arrangement and alignment of the disk packs 51, 53 of the first braking apparatus 45 are present in a combination with a described arrangement and alignment of the disk packs 55, 57 of the second braking apparatus 47 which is not explicitly described in this combination above.

[0032] It is in this respect common to all these embodiments of a hub arrangement 11 that, due to the drive via a differential gear, in particular by avoiding slip, a comparatively small wear is achieved at both wheels or tires associated with the wheel hubs 31, 33 and that, due to the separate actuation of the first braking apparatus 45 of and of the second braking apparatus 47, which also prevent a relative movement of the wheel hubs 31, 33 to one another, a reliable braking of both wheels can be ensured also in a situation of problematic traction. In this respect, in dependence on the respective demand, the respective available construction space can be ideally used by a suitable choice of one of the described embodiments, with the construction simultaneously allowing a good accessibility of the braking apparatus 45, 57 for their control.