DE102004003632A1 - High-level transmission system for e.g. city bus, has hollow wheel with external teeth that mesh with driven wheel to transmit power, and cogs, implemented as conical components, aligned with axis of wheels and reinforcing axial forces - Google Patents

Abstract

The system has a planet wheel rotated around an axle of a planetary wheel. A sun wheel is coupled with an axle shaft of a differential gear of a high-level axle. A hollow wheel has inner and outer teeth arrangements, where external teeth of the hollow cylinder mesh with a driven wheel to transmit power. Pressure cogs (11, 12, 13) implemented as conical components coaxially align with rotary axis of the wheels and reinforce axial forces.

Description

The The present invention relates to a gantry gear for one Portal axle of a vehicle according to the preamble of claim 1

portal axles become common used in local and city bus axes (low-floor axes), to make the clearance of the aisle in the bus as large as possible. Especially with local buses and city buses is also one possible low floor height desirable, around the passengers a comfortable and fast To allow entry and exit. Therefor portal axles are used, in which the axle shafts against the Axles about a certain distance, the so-called portal depth, are offset; Here are the axle bridge and the differential in Lowered middle part of the axle. This misalignment is by each an intermediate gear or a gear ratio directly on the wheel drive, the so-called portal drive enabled.

According to the prior art, in particular the EP 877 672 B1 , The portal drive is driven by a differential shaft with an axle shaft. Usually, the output gear of the gantry gear via two intermediate gears with the drive wheel in operative connection, wherein the axes of rotation of the intermediate wheels and the drive wheel lie in a plane which is parallel to the road surface. The use of two intermediate wheels results in a power split at the drive wheel.

at the aforementioned prior art, the portal distance or the Axial offset between the drive wheel and the output gear can not be increased because therefor a further increase in diameter of the idlers would be necessary what a spring carrier connection according to the prior art disadvantageously not possible.

The Ground clearance of a low-floor axis is determined by the position of the axis of rotation and the diameter of the ring gear of the bevel gear on the differential or differential determined; the bulge for the ring gear is the lowest Point of the axis. Through a larger translation of the portal drive can be the outside diameter of the ring gear are reduced so that by a simultaneous Lowering the axis of rotation of the crown wheel while maintaining the ground clearance the center aisle of the vehicle can be lowered further. To The prior art is a larger translation of the portal drive only by enlargement of the Output wheel or reduction of the drive wheel possible. An enlargement of the Output wheel would have a collision with the brake result; a reduction of the Drive wheel is not possible for reasons of strength.

Of the present invention is based on the object, a portal drive for one Specify portal axis, which has a large axial offset in a possible great translation and low space allows. Through the great translation can the differential and the ring gear advantageously smaller be dimensioned.

These The object is solved by the features of claim 1. Further Embodiments and advantages will become apparent from the dependent claims.

Therefore a portal drive is proposed, which has a planetary gear set an outside and internally toothed ring gear, a sun gear and fixed planets includes, wherein the external teeth the ring gear with the output gear of the portal drive for power transmission combs and wherein the drive of the planetary gearset on the with the axle of the Ausgleichge drove firmly connected sun gear done. The gears are helically toothed executed which is positive for the noise effect. The resulting axial forces are absorbed by pressure combs, which the axially fixed in operative connection with one another. Preferably, the pressure combs exist from disk-shaped Components, each having a disk-shaped component to each one axial end of the gear is arranged and the disc-shaped components of respectively Zahräder in operative connection with each other overlap radially. As a result, the axial teeth forces are directly at the point of origin, namely near supported the tooth mesh. Thus arise for the planetary storage no tilting forces, which adversely affect affect the life of the planetary bearing.

In a further embodiment, the drive wheel also Double-sided pressure combs on, acting on the bearings of the planet gears neither axial forces nor Tilting forces.

By the use of pressure combs can a complex storage of the ring gear omitted, creating a cost effective solution. By doing by using the pressure combs the axial forces near of the pitch circle supported only a slight wear of the pressure combs occurs, there near the rolling circles only slight relative speeds of the pressure combs occur, as for example when using thrust washers would not be the case.

In Another embodiment can also only one way acting pressure comb, which is the main operating direction covering the drive. This pressure comb then takes the axial forces, resulting from helical gearing, each in the most frequently occurring operating direction, preferably a forward direction of the vehicle under tensile load.

The axial forces, which in the other operating states in the other direction act then become over Thrust was added, which are dimensioned smaller can, because the time shares at which these operating conditions occur are low.

Preferably is the axis of rotation of a planetary gear in the plane through the axes of the output gear and the ring gear is defined.

According to one Variant of the present invention, the planet gears can be different be dimensioned, whereby the axis of rotation of the ring gear is not coaxial with the axis of the drive wheel or sun gear.

By the concept of the invention can between the drive and driven gear a horizontal portal offset on low cost Be realized manner, for example, an offset of the axle in the direction of travel enable can.

The The invention will be explained in more detail below with reference to the accompanying figures by way of example.

It represent:

1 a schematic sectional view of a gantry drive according to the invention;

2 a schematic sectional view of a gantry drive according to the invention and

3 a schematic partial view of a portal drive according to the invention comprehensive portal axis.

As in 1 shown, a portal drive according to the invention comprises a planetary gear set 1 with an externally and internally toothed ring gear 2 , a sun gear 3 and fixed but rotatable about the planetary gear planet 4 , wherein the external toothing of the ring gear 2 with an output gear 5 of the portal drive for power transmission meshes. In this case, the drive of the planetary gear set takes place via the sun gear fixedly connected to the axle shaft of the differential gear of the portal axle 3 , The axis of rotation of the sun gear 3 (Drive wheel) is below the axis of rotation of the driven wheel 5 arranged in the direction of the road surface, wherein a horizontal offset is possible.

As shown in the figure, the planetary gear set preferably has three planets 4 on, on the one hand with the internal toothing of the ring gear 2 and on the other hand with the sun gear comb. For load sharing by multiple planets 4 can the diameter of the sun gear 3 small dimensions. The translation is through the planets 4 and the ring gear 2 realized.

According to the invention, the gears are helically toothed. The axial forces are applied via pressure combs, as in 2 shown, supported. Thus, the ring gear needs 2 not be stored directly in the portal housing. The ring gear can be made in one piece, but it is also possible to connect external and internal teeth by suitable fasteners firmly together. The external and internal teeth of the ring gear 2 have the same axis of rotation, but can be offset from each other in the axial direction, so that the planetary gear (planet gears, sun or driven gear, internal gear ring gear) and together with the drive wheel 5 acting as a countershaft outer teeth of the ring gear can be arranged in different planes. At the in 1 shown embodiment, a horizontal portal offset c has been realized between drive and driven gear.

As in 2 shown, meshes the drive wheel 3 with planet wheels 4 , which in turn with the ring gear 2 in operative connection. Coaxial to the axis of rotation of the planet gears 4 are conical pressure crests 11 on each side of the planetary gears 4 attached, in which radially disc-shaped pressure combs 12 intervene, the pressure crests 12 coaxial with the drive wheel 3 are arranged and attached to the pressure crests 11 supported in the axial direction. The support takes place in the vicinity of the rolling circles, whereby a low relative speed occurs. On each side of the ring gear 2 are pressure combs 13 arranged, which are also in the pressure combs 11 support and coaxial with the ring gear 2 are arranged. Thus, the gearing forces are based on the helical gearing in the vicinity of the place of origin.

In 3 is shown further components of the portal axis; Here is the axial offset between the wheel axle 6 and the axle shaft 7 (Portal offset) with 14 designated. By the present invention, a larger portal offset while greater translation in the portal drive while maintaining a conventional connection 8th for the spring carrier 9 and a conventional brake system (the brake cylinder is with 10 Marked net) with sufficient ground clearance 15 allows.

1

planetary set

2

ring gear

3

sun, drive wheel

4

planet

5

output gear

6

wheel axle

7

axle shaft

8th

Spring carrier connection

9

spring support

10

brake cylinder

11

thrust collar

12

thrust collar

13

thrust collar

14

vertical Axial offset, portal offset

15

ground clearance

16

horizontal portal offset

Claims (10)

Portal drive for a portal axle of a vehicle, characterized in that a spur gear ( 5 . 2 ) an axis offset ( 14 ) between a drive wheel ( 3 ) and a driven wheel ( 5 ) of the spur gear is produced wherein the drive wheel of the spur gear is an internally and externally toothed ring gear, wherein at least one toothing is designed as helical toothing, in which the axial forces via pressure combs ( 11 . 12 . 13 ) are supported. Portal drive according to claim 1, characterized in that the ring gear ( 2 ) is driven by a planetary gear. Portal drive according to claim 1 or 2, characterized in that the axes of rotation of the planets ( 4 ) lie in the plane passing through the axes of the driven wheel ( 5 ) and the ring gear ( 2 ) is defined. Portal drive according to claim 1, characterized in that the pressure combs ( 11 . 12 . 13 ) are designed as tapered components, and coaxial with axes of rotation of the gears ( 2 . 3 . 4 ) are arranged. Portal drive according to claim 4, characterized in that the pressure combs ( 12 ) of the drive wheel ( 3 ) of the planetary gear to pressure crests ( 11 ) of planetary gears ( 4 ) and the pressure combs ( 13 ) of the ring gear ( 2 ) are supported on pressure ridges of the planetary gears. Portal drive according to one of the preceding claims, characterized in that the ring gear ( 2 ) is made in one piece or in two parts. Portal drive according to one of the preceding claims, characterized in that the outer and inner teeth of the ring gear ( 2 ) have the same axis of rotation. Portal drive according to one of the preceding claims, characterized in that the outer and inner teeth of the ring gear ( 2 ) are arranged offset from each other in the axial direction. Portal drive according to one of the preceding claims, characterized in that between drive and driven gear ( 3 . 5 ) a horizontal portal offset (c) is realized. Portal drive according to one of the preceding claims, characterized in that the axis of rotation of the sun gear ( 3 ) below the axis of rotation of the driven wheel ( 5 ) is arranged in the direction of the road surface.