DE102016107827A1 - steering gear - Google Patents

Abstract

A steering gear for an axle of a tracked vehicle comprises a superposition gear having an input member, a first output member and a second output member. By driving an input element, a first output element and a second output element are drivable to an opposite rotational movement, and by the direction of rotation of the input member, the respective rotational direction of the first output element and the second output element is adjustable. The superposition gear is configured such that a relationship between the rotational speed of the first output member and the rotational speed of the second output member is predetermined for a given rotational speed of the input member, without within the superposition gearing the rotational speed of the input member uniquely determining the absolute rotational speeds of the first output member and the second output member ,

Description

The present invention relates to a steering gear, in particular for a vehicle with chain drive.

Steering gears for vehicles with chain drive can be arranged in each case between an axis differential arranged along the drive axle and external drive wheels on the drive axle. On the drive axle are thus in coaxial arrangement a first drive wheel, then usually a first brake device, then a first steering gear, the axle differential, a second steering gear, usually a second brake device and a second drive provided. As a result, the space required along the drive axis is large or the available space per component small.

It is the object of the present invention to provide a steering gear for a vehicle, in particular a vehicle with chain drive, which has a simple and compact construction.

This object is achieved by a steering gear having the features of claim 1.

The present invention thus relates to a steering gear for an axle of a tracked vehicle having an axle differential with a drivable by a drive motor drive element (eg, a crown gear or a differential carrier), a first output element (eg, a first axle or a first output bevel gear) and a second output element (eg a second axle shaft or a second driven bevel gear). The two output elements are ultimately coupled to a respective drive wheel of a track drive. In such an axle differential, for which the present invention is used, the transmission ratio between the first output element and the second output element is at idle drive element typically i = -1, and by the speed of the drive element of the axle differential, the average speed of the first output element and the second output element can be specified.

The steering gear comprises a superposition gearbox with a rotatable input element, a rotatable first output element and a rotatable second output element, wherein the input element by means of an auxiliary drive source, for example a hydraulic motor, is driven to a rotational movement. By driving the input element, the first output element and the second output element are drivable to a mutually opposite rotational movement, which is superimposed on an average rotational speed of the first output element and the second output element, said mean rotational speed can also be zero. Further, by the direction of rotation of the input member, the respective rotational direction of the first output member and the second output member relative to the average rotational speed adjustable.

In this case, the superposition gear sets a relationship between the rotational speed of the first output member and the rotational speed of the second output member at a given speed of the input member, but without the sole of the superposition gear or its elements and arrangement, the speed of the input element, the rotational speeds of the first output element and the second Specifies the starting element uniquely. Rather, this definition is done by the coupling of the steering gear with the axle differential.

The first output element of the superposition gear is for this purpose with the first output element of the axle differential and the second output element of the superposition gear is coupled to the second output element of the axle differential or coupled (for example via a respective spur gear or other driving connection). Only then, i. by the coupling of the superposition gearing with the axle differential, an unambiguous dependence of the rotational speeds of the first output element and the second output element of the superposition gearing on the rotational speed of the input element (and possibly of further rotational speeds of the steering gear, in particular the average rotational speed of the first output element and the second output element ) or produced.

When driving the rotatable input element preferably results in a translation into slow, but it does not necessarily equal speeds of the two output elements with inverse sign result. The superposition gear is not clearly determined. The ambiguous certainty may be generated, for example, by the superposition gear having a freely rotatable component (e.g., a common ring gear or a common sun gear of two planetary gears of the superposition gear).

Finally, the superposition gearing thereby has a degree of freedom whereby, given a rotational speed of the input member, a relationship between the rotational speed of the first output member and the rotational speed of the second output member (specifically, a rotational speed difference or a rotational speed ratio between the first output member and the second output member) may be set. However, they are As a result, the absolute speeds of the output elements are not clearly defined.

However, if the superposition gearing is coupled with an associated axle differential, then the overall system of superposition gearing and axle differential no longer has any degree of freedom. The axle differential forces namely that the rotational speeds of the two output elements of the superposition gear (as well as the rotational speeds of the two output elements of the axle differential) are distributed symmetrically about the average speed of the two output elements. At the axle differential, the speed of the second output element is, for example, N - n, when N is the speed of the drive element (or the average speed of the two output elements) and N + n is the speed of the first output element. Thus, by the axle differential, a further condition between the rotational speeds of the output elements of the superposition gear, which are coupled to the output elements of the axle differential, whereby the overall system of superposition gear and axle differential is determined.

By driving the drive element of the axle differential, an average rotational speed of the first output element and the second output element of the axle differential and thereby an average rotational speed of the first output element and the second output element of the superposition gear can be adjusted to specify a driving speed. Through the steering gear can be superimposed (in cooperation with the axle differential) of the driving movement (v = 0 or | v |> 0) a steering movement.

An advantage of the steering gear according to the invention is that an axle differential available as a standard structural unit can be included in the steering gear. The steering gear may in particular be a separate unit from the axle differential, e.g. with its own housing.

An additional advantage of the invention is that the drive torque generated by the drive motor (e.g., engine) is transmitted solely through the axle differential and the two associated axle shafts but not via the steering gear. About the steering gear only the steering power is performed so that the steering gear can be relatively small dimensions. On the one hand, this can result in weight savings and, on the other hand, cost savings. In particular, a narrow construction in the axial direction is possible because the essential components of the steering gear can be arranged on the vehicle axle radially with respect to the axle differential.

In connection with the invention, it should be noted that "coupled" and "producible" refer to optional couplings in a modular design, as explained below. A drive-effective connection between two rotatable elements means a connection in which the two rotatable elements are non-rotatably coupled or in a fixed rotational relationship to one another (for example via a spur gear stage). The steering gear according to the invention need not be permanently coupled to the associated axle differential. The vehicle can also be driven without the steering gear via the axle differential, wherein a steering movement then has to be effected via a different steering mechanism, such as via a respective steering knuckle or articulated steering.

Advantageous embodiments of the invention are described in the dependent claims, the description and the drawings.

In order to use as many equal parts, the coupling of the first output element of the superposition gearing with the input element and the coupling of the second output element of the superposition gearing with the input element (apart from a possibly provided Reversierstufe) may be constructed symmetrically to each other. In other words, a reversing stage can additionally be provided in only one of the two power paths, in order to bring about a reversal of the rotational direction and thereby to be able to drive the first output element and the second output element of the superimposed gearbox to an opposite rotational movement. Instead of the reversing stage, a central arrangement of the input element and / or a bevel gear can be provided for generating mutually opposite rotational movements of the output elements.

According to one embodiment, the superposition gearing comprises a differential gearing arrangement comprising a first rotatable component coupled to the first output element of the superposition gearing and a second rotatable component coupled to the second output element of the superposition gearing, the first component and the second Component are driven in opposite directions by means of the input member to each other, and wherein the first component and the second component are supported on a freely rotatably mounted third component of the differential gear assembly. By freely rotatably mounted third component, the first output element and the second output element are drivingly coupled together, wherein based on the drive movement of the input member allows a speed compensation becomes. The desired degree of freedom can thus be provided within the superposition gearing by the third component.

The first component and the second component of the differential gear arrangement can be constructed identically according to a particularly simple embodiment and arranged symmetrically to each other. Further, the first component and the second component may be coaxially arranged components of a planetary gear train.

In a preferred embodiment, the superposition gearing comprises a first planetary gearing and a second planetary gearing, wherein a first element of the respective planetary gearing is coupled directly or indirectly to the input element of the superimposition gearing, a second element of the first planetary gearing fixed to a second element of the second planetary gearing is connected, a third element of the first planetary gear with the first output element of the superimposed transmission - indirectly or directly - is coupled and a third element of the second planetary gear with the second output element of the superposition gearing - indirectly or directly - coupled. As a result, a compact design of the superposition gear is possible.

But the superposition gear can also have other types of differential gears and / or planetary gears instead of the planetary gear.

The first planetary gear and the second planetary gear can be constructed according to an advantageous simple embodiment identical to each other and arranged symmetrically to each other.

Furthermore, the first planetary gear and the second planetary gear are preferably arranged coaxially to each other, in particular with a common central axis.

The second element of the first planetary gear and the hereby firmly connected second element of the second planetary gear can be freely rotatably mounted to provide a degree of freedom (ambiguous determination) of the superposition gear.

A particularly simple generation of the opposite rotational movement of the first elements of the planetary gear can be achieved in that the first element is coupled only one of the two planetary gear via a reversing stage with the input element of the superposition gear. For example, such a Reversierstufe be formed by an additional spur gear.

Alternatively, the generation of the opposite rotational movement of the first elements of the planetary gear can be effected by a bevel gear.

In particular, it can be provided that the first planetary gear and the second planetary gear have a common central axis, wherein the axis of rotation of the input element of the superposition gear is perpendicular (ie radially) aligned with the common central axis, wherein the input element with both the first element of the first planetary gear or a Actuator element coupled thereto is engaged as well as engaged with the first element of the second planetary gear or a member operatively coupled therewith. As a result, it can be achieved in a particularly simple manner that the elements driven by the input element are driven in opposite directions. In particular, for this purpose, the elements driven by the input element can be rotatably mounted axially parallel to the common central axis of the planetary gear.

According to one embodiment, the superposition gearing has an input gearing via which the first element of the first planetary gearing and the first element of the second planetary gearing are coupled to the input element of the superposition gearing.

The input gearbox may include an input bevel gear according to one embodiment. The input bevel gear may mesh with a first output bevel gear and a second output bevel gear such that the output bevel gears are drivable in mutually opposite directions of rotation. Preferably, the output bevel gears are aligned coaxially with each other. The output shaft bevel gears may be drivingly coupled to the respective first element of the planetary gears, for example via a respective spur gear.

According to a preferred embodiment, the input gear has an input shaft, a first spur gear and reversing stage for coupling the input shaft to the first element of the first planetary gear and a second spur gear for coupling the input shaft to the first element of the second planetary gear.

The first planetary gear and the second planetary gear may each have a sun gear, a ring gear and a planetary gear bearing a plurality Have planet carrier. In this case, the diameters of the respective sun gears, the diameters of the respective planetary gears and / or the diameters of the respective ring gears of the two planetary gears can match. Alternatively, the planetary gear can also be designed differently. For example, the planetary gear may have two sun gears and one or more double planets.

Assign the first planetary gear and the second planetary gear each have a sun gear, a ring gear and a planetary carrier supporting planet carrier, according to an advantageous embodiment, the sun gear, the first element, the ring gear, the second element and the planet carrier, the third element of the respective planetary gear. Again, alternative embodiments are possible, for example when the sun gear, the first element, the planet carrier, the second element and the ring gear forms the third element of the respective planetary gear. According to a further embodiment, the ring gear forms the first element, the sun gear, the second element and the planet carrier, the third element of the respective planetary gear.

These embodiments have in common that the mutually corresponding elements of the first and second planetary gear are formed by the same components (sun gear, planet carrier, ring gear) of the respective planetary gear.

According to one embodiment, the first output element of the superposition gearing is coupled or coupleable to the first output element of the axle differential via a first output spur gear stage, and the second output element of the superposition gearing is coupled or coupleable to the second output element of the axle differential via a second output spur gear stage. This embodiment is particularly well suited for retrofitting to an existing axle differential due to the simple coupling with the output elements of the axle differential. In order to convert the axle, which is preferably a drive axle, to use the steering gear, only one gear has to be arranged on each output element of the axle differential or on the associated axle shaft.

To facilitate assisted steering, the steering gear may further include the auxiliary drive source. The auxiliary drive source is preferably formed by a hydraulic motor or an electric motor. The auxiliary drive source can also be formed by any other type of motor. Furthermore, the auxiliary drive source can derive the required drive torque from the drive motor of the vehicle. The auxiliary drive source is preferably connected to a control device of the vehicle and controlled by means of two different commands in opposite directions.

Furthermore, the object of the invention is achieved by a vehicle axle with an axle differential and a previously described steering gear.

In this case, the axle differential preferably has a drive element drivable by a drive motor, a first output element and a second output element.

The axle differential may in particular be designed as a bevel gear differential. The drive element, which is driven by the drive motor, drives via a cage radially aligned axes of rotation of a plurality of bevel gears, which mesh with a first and second output bevel gear. The first and second driven bevel gears are each non-rotatably connected to or formed by the first and second output elements. The first output element and the second output element are preferably connected to the respective axle shaft.

In order to design the wheels of a drivable vehicle axle selectively steerable, the steering gear can form an optionally mountable to the axle differential assembly.

An embodiment which is particularly narrow in the axial direction results when the steering gear is arranged on the vehicle axle radially with respect to the axle differential. According to a particularly simple embodiment, two gears arranged or formed on the axle shafts form the only components of the axle differential for the steering gear on the vehicle axle.

The object of the invention is further achieved by a steering gear for an axle of a tracked vehicle having an axle differential with a drivable by a drive motor drive element, a first output element and a second output element, wherein the steering gear is a superposition gear with an input element, a first output element and a second output element; wherein the input element is drivable by means of an auxiliary drive source to a rotary movement, wherein by driving the input element, the first output element and the second output element are drivable to a mutually opposite rotational movement, the average speed of superimposed on the first output element and the second output element, wherein the rotational direction of the input element, the respective rotational direction of the first output element and the second output element is adjustable relative to the average rotational speed of the first output element and the second output element; wherein the superposition gearing further comprises a first planetary gearing and a second planetary gearing, a first element of the respective planetary gearing being coupled directly or indirectly to the input element of the superimposition gearing, a second element of the first planetary gearing being fixedly connected to a second element of the second planetary gearing; a third element of the first planetary gear is coupled to the first output element of the superposition gearing, directly or indirectly, and a third element of the second planetary gearing is coupled directly or indirectly to the second output element of the superposition gearing. The first planetary gear and the second planetary gear can in particular be designed as explained above or coupled to the axle differential.

The invention will now be described by way of a purely exemplary embodiment with reference to the accompanying drawings. Features of the described embodiment can be combined with each other arbitrarily. Identical or similar elements are identified by the same reference numerals. Show it:

1 a schematic diagram of a vehicle with a steering gear according to the invention;

2 a schematic diagram of a vehicle axle with a steering gear according to the invention according to a first embodiment;

3A to 3C various driving state modes of the steering gear;

4 a schematic diagram of a vehicle axle with a steering gear according to the invention according to a second embodiment; and

5 a schematic diagram of a vehicle axle with a steering gear according to the invention according to a third embodiment.

The figures show a steering gear 10 which is connected to one with an axle differential 12 equipped axle is attachable to a tracked vehicle or a similar vehicle, such as a vehicle with wheels, which should be able to turn on the spot, by means of this steering gear 10 to steer.

As in 1 can be seen, such a vehicle according to one embodiment comprises a drive axle 14 which are essentially between two drive wheels 16 . 16a extends. At the drive axle 14 is essentially centered the axle differential 12 arranged in which 1 is shown schematically. Radially spaced from the axle differential 12 is the steering gear 10 arranged, which is also shown schematically.

The vehicle has a drive train which, starting from a drive motor 18 via a drive element 20 to the axle differential 12 leads. At the axle differential 12 shares the drive train, so that a part of the drive power through a first output element 22 and another part of the drive power via a second output element 24 to be led. The first output element 22 drives the first drive wheel 16 and the second output element 24 drives the second drive wheel 16a at.

The steering gear 10 , which by an auxiliary drive source 30 with a torque M _{D, one can be} acted upon, is substantially radially spaced from the drive axis 14 and thus not on the drive axle 14 (ie not coaxial with the output elements 22 . 24 ) arranged. The steering gear 10 is, however, each with the first output element 22 and the second output element 24 drivingly connected to the first output element 22 and the second output element 24 to be able to move in opposite directions to the steering of the vehicle.

In 2 is a schematic representation of the steering gear 10 in connection with the drive axle 14 shown according to a first embodiment. The steering gear 10 includes a superposition gearbox 26 with an input gear 27 and a planetary gear arrangement 28 ,

The steering gear 10 also has the auxiliary drive source 30 , For example, a hydraulic motor or electric motor. The auxiliary drive source 30 is designed to be a rotatable input element 32 to drive either clockwise or counterclockwise. The driver can select the direction of rotation and the speed by means of suitable control means (not shown). The input element 32 , which is formed as an input shaft, is connected to a first Reversiergetriebezahnrad 34 and a first spur gear 36 fitted. The first reversing gear 34 stands with a second Reversiergetriebezahnrad 38 meshing and the second Reversiergetriebezahnrad 38 stands with a third Reversiergetriebezahnrad 40 meshing. The first reversing gear 34 and the third reversing gear 40 turn in the same direction. The reversing gear wheels 34 . 38 and 40 form a so-called spur gear and Reversierstufe 42 ,

The third reversing gear 40 is non-rotatable with a first element 44 a first planetary gear 46 coupled. The first element 44 is thus driving effective with the input element 32 coupled. The first element 44 is the sun gear of the first planetary gear 46 educated. The first element 44 meshes with several planetary gears 48 , which are rotatably mounted on a planet carrier, which is a third element 50 of the first planetary gear 46 forms. The planet wheels 48 are also provided with a second element formed as a ring gear 52 meshing. The trained as a ring gear second element 52 of the first planetary gear 46 is freely rotatable in one - in 2 only schematically indicated - planetary gear housing 54 stored.

The third element 50 of the first planetary gear 46 (Planet carrier) is drive-effective, namely rotationally fixed, with a first output element 56 of the superposition gearbox 26 coupled. With the first output element 56 is a first output spur gear 58 rotatably connected. The first output spur wheel gear 58 is meshing with a second output spur wheel gear 60 engaged, which rotatably with the first output element 22 of the axle differential 12 is coupled. The second output spur gear 60 is located substantially between the axle differential 12 and the first drive wheel 16 ( 1 ).

The previously described part of the steering gear 10 represents a first power path, namely that for driving the first drive wheel 16 , dar.

Further, on the input element 32 the already mentioned first spur gear toothed wheel 36 intended. This is in mesh with a second spur gear 62 engaged. The first spur gear 36 and the second spur gear 62 together form a spur gear 63 , The second spur gear 62 is non-rotatable with a first element 44a a second planetary gear 46a coupled. The first element 44a is thus - like the first element 44 of the first planetary gear 46 - Driveable with the input element 32 coupled, but in this regard with the reverse direction. The first element 44a forms a sun gear of the second planetary gear 46a , The diameter of the first element 44a of the second planetary gear 46a and the diameter of the first element 44 of the first planetary gear 46 correspond. The first element 44a of the second planetary gear 46a (Sun wheel) is meshing with planetary gears 48a of the second planetary gear 46a engaged. The planet wheels 48a have the same diameter as the planetary gears 48 of the first planetary gear 46 , The planet wheels 48a stand with a second element formed as a ring gear 52a of the second planetary gear 46a meshing. The second element 52a of the second planetary gear 46a (Ring gear) is integral with the second element 52 of the first planetary gear 46 (Ring gear) formed. The inner diameter of the toothing of the second element 52 corresponds to the inner diameter of the toothing of the second element 52a ,

The planet wheels 48a are rotatably mounted on a planet carrier, which is a third element 50a of the second planetary gear 46a forms and with a second output element 64 of the superposition gearbox 26 drive-effective, namely rotationally fixed, is coupled. The second output element 64 is with a first output spur gear 58a rotatably coupled, which meshing with a second Ausgangsstirnradstufenzahnrad 60a communicating with the second Ausgangsstirnradstufenzahnrad 60a rotatably with the second output element 24 of the axle differential 12 is coupled.

One through the first output spur gear 58 and the second output spur gear 60 formed first Ausgangsstirnradstufe 66 is the same structure as one through the first Ausgangsstirnradstufenzahnrad 58a and the second output spur gear 60a formed second Ausgangsstirnradstufe 68 , In this context, the same design means, in particular, that the diameters of the first output spur gear wheels 58 . 58a correspond and the diameters of the second Ausgangsstirnradstufenzahnräder 60 . 60a correspond.

The above-described part of the steering gear 10 provides a second power path, namely that for driving the second output element 24 it axle differential 12 and thus the second drive wheel 16a of the vehicle ( 1 The first power path and the second power path are related in that they together form the second element (the second elements or ring gears fixedly connected to each other) 52 . 52a ) of the planetary gear 46 . 46a driving at a common speed.

How out 2 it can be seen is the steering gear 10 except for the spur and Reversierstufe 42 or spur gear stage 63 center symmetrical.

That the steering gear 10 assigned axle differential 12 is designed as a bevel gear differential and includes a differential carrier 70 , which with the trained as a crown wheel drive element 20 is firmly connected. At the differential carrier 70 are two pinion gears 74 . 75 rotatably mounted, wherein the axes of rotation of the bevel gears 74 . 75 are aligned with each other and perpendicular to the axle shafts 76 trained output elements 22 . 24 are aligned. The bevel gears 74 . 75 are each meshing with output bevel gears 78 . 79 engaged, wherein the output bevel gear 78 rotatably with the first output element 22 and the second output bevel gear 79 rotatably with the second output element 24 are coupled.

A special feature of the steering gear 10 or of the superposition gearing 26 is that although a relationship between the rotational speed of the first output element 56 and the rotational speed of the second output element 64 at a given speed of the input element 32 is predetermined, but not only by the superposition gearbox 26 or its elements and arrangement the speed of the input element 32 the absolute speeds of the first output element 56 and the second output element 64 clearly states. This is done only due to the coupling or interaction of the superposition gearing 26 with the axle differential 12 , between its output elements 22 . 24 a predetermined level ratio is provided (ratio of i = -1 between the first output element 22 and the second output element 24 with stationary drive element 20 ).

Based on 3A to 3C now different driving modes will be described.

3A shows a driving mode in which the tracked vehicle is steered straight ahead. The drive motor 18 drives the drive element 20 of the axle differential 12 with a certain torque M _{D, engine} and a certain _engine speed N _engine , for example M _{D, engine} = 2000 Nm and N _engine = 2000 rpm. The axle differential 12 then distributes the torque M _{D, engine} evenly on the first output element 22 and the second output element 24 or the drive wheels 16 and 16a ( 1 ). Thus, at each of the drive wheels 16 . 16a For example, a torque of 1000 Nm at 2000 rev / min, that is M _{D, aus1} = M _{D, aus2} = 1000 Nm and N _{out, 1} = N _{out, 2} = 2000 U / min. The auxiliary drive source 30 does not generate torque (M _{D, a} = 0 Nm), so over the steering gear 10 no torque is transmitted.

3B shows a driving condition in which the tracked vehicle turns in place. This is done by the drive motor 18 no torque (M _{D, motor} = 0 Nm) on the axle differential 12 transfer. Only the auxiliary drive source 30 generates a torque M _{D, one} on the input element 32 , For example, _{D M, a} = 1100 Nm at _a N = 2000 U / min. About the input gear 27 (Spur gear and Reversierstufe 42 and spur gear 63 ) are at the input elements of the planetary gear 46 . 46a (Sun gears 44 . 44a ) generates opposing speeds. About the planetary gear 46 . 46a as well as the output spur gear stages 66 . 68 become equal large torques M _{D, aus1} and M _{D, aus2} on the output elements 22 . 24 of the axle differential 12 in terms of magnitude, the same rotational speeds N out of ₁ , N out of ₂ , but with different signs, are generated. The steering gear 10 causes a translation of the rotational movement of the input element 32 slow. For example, lies on the first output element 22 a torque M _{D, out1} of 5500 Nm at N _aus1 = -200 rpm, while at the second output element 24 a torque M _{D, aus2} of 5500 Nm at N _aus1 = 200 U / min is applied.

3C describes a vehicle mode in which the tracked vehicle is cornering. This is superimposed on one of the auxiliary drive source 30 provided torque M _{D, one of} the drive motor 18 provided torque M _{D, engine} . For example, the drive motor provides 18 a torque M _{D, engine} of 2000 Nm at N _engine = 2000 rpm, which, as already in 3A described evenly on the first output element 22 and the second output element 24 of the axle differential 12 divides. Thus lies, of the drive motor 18 generated at each of the drive wheels 16 . 16a a torque M _{D, engine, from} 1000 Nm at N _{engine, off} = 2000 rpm. However, this torque M _{D, motor, off} is superimposed by one of the auxiliary drive source 30 generated torque M _D , which, via the steering gear 10 is transmitted. For example, the auxiliary drive source 30 a torque M _{D, one} of 500 Nm at N _a = 2000 rpm ready. This torque M _{D, one of} the auxiliary drive source 30 generated at the first output element 22 a torque M _{D, A, aus1} of 2500 Nm at N _{A, from 1} = -200 rpm and at the second output element 24 a torque M _{D, A, aus2} of 2500 Nm at N _{A, aus2} = 200 U / min.

If the two torques are superimposed, the result is the first output element 22 a torque M _{D, motor, from} + M _{D, A, from 1} = M _{D, from 1} of 3500 Nm at N _{motor, from} + N _{A, from 1} = N from ₁ = 1800 rpm, and at second output element 24 a torque M _{D, engine, from} + M _{D, A, out 2} = M _{D, out 2} from 3500 Nm at N _{engine, from} + N _{A, from 2} = N out ₂ = 2200 rpm. This creates a speed difference between the first drive wheel 16 and the second drive wheel 16a which causes the tracked vehicle to make a turn. Depending on the direction of rotation of the input element 32 (either right-handed or left-leaning) the tracked vehicle drives a right turn or a left turn.

In 4 is a schematic representation of a steering gear 10 shown according to a second embodiment. Unlike the first embodiment according to 2 forms with both planetary gears 46 . 46a the ring gear is the first element 44 ' . 44a ' , the sun gear is the second element 52 ' . 52a ' and the planet carrier the third element 50 ' . 50a ' ,

Thus, in this embodiment, the third reversing gear is 40 rotatably with the ring gear 44 ' of the first planetary gear 46 coupled and the second spur gear 62 rotatably with the ring gear 44a ' coupled. The ring gears 44 ' . 44a ' mesh with several planetary gears 48 ' . 48a ' rotatable on the planet carriers 50 ' . 50a ' are stored. The planet wheels 48 ' . 48a ' are further provided with the second sun gear formed as a respective element 52 ' . 52a ' meshing. The rotatably connected sun gears 52 ' . 52a ' of the first planetary gear 46 and second planetary gear 46a are freely rotatable together in one - also in 4 only schematically indicated - planetary gear housing 54 stored.

The respective third element 50 ' . 50a ' the planetary gear 46 . 46a (Planet carrier) is rotationally fixed with a respective output element 56 . 64 of the superposition gearbox 26 coupled.

5 shows an alternative embodiment for generating mutually opposite rotational movements of the first output element 56 and the second output element 64 the planetary gear 46 . 46a , Instead of a Reversierstufe 42 with three spur gears (see 2 to 4 ) According to this embodiment, a bevel gear 80 for generating mutually opposite rotational movements of the first elements 44 . 44a the planetary gear 46 . 46a and thus the first output element 56 and the second output element 64 intended. The bevel gear 80 includes one on the input member 32 attached input shaft bevel gear 81 , a first with the input bevel gear 81 meshing output shaft bevel gear 82 and a second one with the input bevel gear 81 meshing output shaft bevel gear 84 , The axis of rotation of the input bevel gear 81 is perpendicular to a common central axis of the planetary gear 46 . 46a aligned. The output shaft bevel gears 82 . 84 are rotatably mounted axially parallel to the common central axis. The bevel gear 80 is symmetrical, so that the gear ratio between the first output bevel gear 82 and the second output bevel gear 84 of the bevel gear 80 i = -1. In other words, the two output bevel gears rotate 82 . 84 with driven input element 32 in terms of amount equally fast, but in opposite directions.

The first output bevel gear 82 is over a first output shaft 86 with a first spur gear 36 a first spur gear 63a rotatably coupled, which meshingly engages a second Stirnradgetriebezahnrad 62 stands, with the first element 44 of the first planetary gear 46 rotatably connected. The second output bevel gear 84 is on the other hand via a second output shaft 90 with a first spur gear 36a a second spur gear 63a rotatably coupled, which meshingly engages a second Stirnradgetriebezahnrad 62a stands, with the first element 44a of the second planetary gear 46a rotatably connected.

It is understood that the generation of the opposing rotational movements by means of the bevel gear 80 with each type of planetary gear arrangement (for example, the first element is sun gear according to 2 or first element is ring gear according to 4 ) can be combined.

The steering gear shown in the figures 10 has the advantage of being at least substantially radial to the axle differential 12 can be arranged and thus little space in the axial direction on the drive axle 14 needed. Furthermore, it can be used to one already with an axle differential 12 equipped axle to convert to a steering axle, without having to make significant changes to the axis. Above all, an already existing axle differential 12 on the axis 14 remain. In addition, for coupling with the steering gear 10 only two gears 60 . 60a on the already existing drive axle 14 to be ordered. In a case where the steering gear 10 is defective or no longer needed, it can be removed from the tracked vehicle, the tracked vehicle is then still roadworthy and at least straight ahead. Another advantage of the steering gear shown 10 is that the drive torque M _{D, motor} , that is, the moment, that of the drive motor 18 is provided and to the drive wheels 16 . 16a is guided, not over the steering gear 10 is guided and thus the steering gear 10 Smaller dimensions than when integrating the steering gear 10 in the power path of the drive motor 18 ,

LIST OF REFERENCE NUMBERS

10

 steering gear

12

 axle differential

14

 drive axle

16, 16a

 drive wheels

18

 drive motor

20

 driving element

22

 first output element

24

 second output element

26

 Superposition gear

27

 input gear

28

 Planetary gear assembly

30

 Auxiliary power source

32

 input element

34

 first reversing gear

36, 36a

 first spur gear

38

 second reversing gear

40

 third reversing gear

42

 Helical and reversing stage

44, 44a

 first element

46

 first planetary gear

46a

 second planetary gear

48, 48a

 planetary gears

50, 50a

 third element

52, 52a

 second element

54

 Planetary gear housing

56

 first output element

58

 first output spur wheel gear

60

 second output spur wheel gear

62, 62a

 second spur gear

63

 spur gear

64

 second output element

66

 first output spur gear stage

68

 second output spur gear stage

70

 differential carrier

74, 75

 Pinions

76

 axle shaft

78, 79

 Output bevel gears

80

 bevel gear

81

 Eingangswellenkegelrad

82

 first output bevel gear

84

 second output bevel gear

86

 first output shaft

90

 second output shaft

Claims (15)

Steering gear ( 10 ) for one axis ( 14 ) of a tracked vehicle having an axle differential ( 12 ) with one of a drive motor ( 18 ) drivable drive element ( 20 ), a first output element ( 22 ) and a second output element ( 24 ), wherein the steering gear ( 10 ) a superposition gear ( 26 ) with an input element ( 32 ), a first output element ( 56 ) and a second output element ( 64 ) having; the input element ( 32 ) by means of an auxiliary drive source ( 30 ) is drivable to a rotational movement, wherein by driving the input element ( 32 ) the first output element ( 56 ) and the second output element ( 64 ) are drivable to a mutually opposite rotational movement, the average rotational speed of the first output element ( 56 ) and the second output element ( 64 ) is superimposed, whereby by the direction of rotation of the input element ( 32 ) the respective direction of rotation of the first output element ( 56 ) and the second output element ( 64 ) relative to the average rotational speed of the first output element ( 56 ) and the second output element ( 64 ) is adjustable; whereby by the superposition gear ( 26 ) a relationship between the rotational speed of the first output element ( 56 ) and the speed of the second output element ( 64 ) at a given speed of the input element ( 32 ) is predetermined, without that within the superposition gearing ( 26 ) the speed of the input element ( 32 ) the rotational speeds of the first output element ( 56 ) and the second output element ( 64 ) clearly states; and wherein the first output element ( 56 ) of the superposition gearing ( 26 ) with the first output element ( 22 ) of the axle differential ( 12 ) and the second output element ( 64 ) of the superposition gearing ( 26 ) with the second output element ( 24 ) of the axle differential ( 12 ) coupled or can be coupled, whereby only thereby a clear dependence of the rotational speeds of the first output element ( 56 ) and the second output element ( 64 ) of the superposition gearing ( 26 ) of the speed of the input element ( 32 ) or can be produced. Steering gear according to claim 1, wherein the coupling of the first output element ( 56 ) of the superposition gearing ( 26 ) with the input element ( 32 ) and the coupling of the second output element ( 64 ) of the superposition gearing ( 26 ) with the input element ( 32 ) completely symmetrical to one another or with the exception of one reversing stage ( 42 ) are constructed symmetrically to each other. Steering gear according to claim 1 or 2, wherein the superposition gear ( 26 ) has a differential gear arrangement comprising a first rotatable component connected to the first output element ( 56 ) of the superposition gearing ( 26 ) and a second rotatable component connected to the second output element ( 64 ) of the superposition gearing ( 26 ), wherein the first component and the second component are connected by means of the input element ( 32 ) are driven in opposite directions to each other, and wherein the first component and the second component are supported on a freely rotatably mounted third component of the differential gear assembly. Steering gear according to at least one of claims 1 to 3, wherein the superposition gear ( 26 ) a first planetary gear ( 46 ) and a second planetary gear ( 46a ), wherein a first element ( 44 . 44 '; 44a . 44a ' ) of the respective planetary gear with the input element ( 32 ) of the superposition gearing ( 26 ), a second element ( 52 . 52 ' ) of the first planetary gear ( 46 ) with a second element ( 52a . 52a ' ) of the second planetary gear ( 46a ), a third element ( 50 . 50 ' ) of the first planetary gear ( 46 ) with the first output element ( 56 ) of the superposition gearing ( 26 ) is coupled and a third Element ( 50a . 50a ' ) of the second planetary gear ( 46a ) with the second output element ( 64 ) of the superposition gearing ( 26 ) is coupled. Steering gear according to claim 4, wherein the first planetary gear ( 46 ) and the second planetary gear ( 46a ) are constructed identically and arranged symmetrically to each other; and / or wherein the first planetary gear ( 46 ) and the second planetary gear ( 46a ) are arranged coaxially with each other; and / or wherein the second element ( 52 . 52 ' ) of the first planetary gear ( 46 ) and the second element ( 52a . 52a ' ) of the second planetary gear ( 46a ) are freely rotatably mounted. Steering gear according to at least one of claims 4 and 5, wherein the first element ( 44 . 44 ' ) only one of the two planetary gear ( 46 ) via a reversing stage ( 42 ) with the input element ( 32 ) of the superposition gearing ( 26 ) is coupled; or wherein the first planetary gear ( 46 ) and the second planetary gear ( 46a ) have a common central axis, wherein the axis of rotation of the input element ( 32 ) of the superposition gearing ( 26 ) is oriented perpendicular to the common central axis, wherein the input element ( 32 ) with both the first element of the first planetary gear ( 46 ) or an element coupled therewith ( 82 ) is engaged as well as with the first element of the second planetary gear ( 46a ) or an element coupled therewith ( 84 ) is engaged. Steering gear according to at least one of claims 4 to 6, wherein the superposition gear ( 26 ) an input gear ( 27 . 80 ), via which the first element ( 44 . 44 ' ) of the first planetary gear ( 46 ) and the first element ( 44a . 44a ' ) of the second planetary gear ( 46a ) with the input element ( 32 ) of the superposition gearing ( 26 ) are coupled. Steering gear according to claim 7, wherein the input gear ( 27 ) an input shaft ( 32 ), a first spur gear and reversing stage ( 42 ) for coupling the input shaft ( 32 ) with the first element ( 44 . 44 ' ) of the first planetary gear ( 46 ) and a second spur gear stage ( 63 ) for coupling the input shaft ( 32 ) with the first element ( 44a . 44a ' ) of the second planetary gear ( 46a ) having; or where the input gear ( 80 ) an input shaft bevel gear ( 81 ) and a first and second with the input shaft bevel ( 81 ) engaged output shaft bevel gear ( 82 . 84 ), wherein the first output bevel gear ( 82 ) with the first element ( 44 ) of the first planetary gear ( 46 ) is drivingly coupled and the second output bevel gear ( 84 ) with the first element ( 44a ) of the second planetary gear ( 46a ) is drive-coupled. Steering gear according to at least one of claims 4 to 8, wherein the first planetary gear ( 46 ) and the second planetary gear ( 46a ) each have a sun gear, a ring gear and a planetary carrier carrying a plurality of planet gears. Steering gear according to claim 9, wherein the sun gear is the first element ( 44 ), the ring gear is the second element ( 52 . 52a ) and the planet carrier the third element ( 50 ) of the respective planetary gear ( 46 . 46a ) forms; or wherein the ring gear is the first element ( 44 ' . 44a ' ), the sun gear is the second element ( 52 ' . 52a ' ) and the planet carrier the third element ( 50 ' . 50a ' ) of the respective planetary gear ( 46 . 46a ). Steering gear according to at least one of the preceding claims, wherein the first output element ( 56 ) of the superposition gearing ( 26 ) via a first Ausgangsstirnradstufe ( 66 ) with the first output element ( 22 ) of the axle differential ( 12 ) is coupled or coupleable, and wherein the second output element ( 64 ) of the superposition gearing ( 26 ) via a second Ausgangsstirnradstufe ( 68 ) with the second output element ( 24 ) of the axle differential ( 12 ) is coupled or can be coupled. Steering gear according to at least one of the preceding claims, wherein the steering gear ( 10 ) the auxiliary drive source ( 30 ), wherein the auxiliary drive source ( 30 ) is formed by a hydraulic motor or an electric motor. Vehicle axle ( 14 ) with an axle differential ( 12 ) and a steering gear ( 10 ) according to any one of the preceding claims. A vehicle axle according to claim 13, wherein the axle differential ( 12 ) one of a drive motor ( 18 ) drivable drive element ( 20 ), a first output element ( 22 ) and a second output element ( 24 ), wherein the transmission ratio between the first output element ( 22 ) and the second output element ( 24 ) of the axle differential ( 12 ) with stationary drive element ( 20 ) i = -1, and wherein by the rotational speed of the drive element ( 20 ) of the axle differential ( 12 ) the average rotational speed of the first output element ( 22 ) and the second output element ( 24 ) and over here the mean speed of the first output element ( 56 ) and the second output element ( 64 ) of the superposition gearing ( 26 ) can be specified. A vehicle axle according to claim 13 or 14, wherein the steering gear ( 10 ) an optional to the axle differential ( 12 ) mountable assembly forms around the vehicle axle ( 14 ) optionally steerable; and / or wherein the steering gear ( 10 ) on the vehicle axle ( 14 ) radially with respect to the axle differential ( 12 ) is arranged.

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