DK2098432T4

DK2098432T4 - Drive string for a motor vehicle with two equal driving directions

Info

Publication number: DK2098432T4
Application number: DK09002919.0T
Authority: DK
Inventors: Frieder Denteler
Original assignee: Voith Patent Gmbh
Priority date: 2008-03-03
Filing date: 2009-03-02
Publication date: 2017-02-13
Also published as: ES2399947T3; DE102008012272A1; EP2098432B1; ES2399947T5; EP2098432B2; EP2098432A1; DK2098432T3

Description

The present invention relates to a motor vehicle drive train for a vehicle with two equivalent travelling directions, and therefore especially for a rail vehicle.

In the case of vehicles with two equivalent travelling directions, i.e. in the case of vehicles such as rail vehicles which can be moved by their own drive motor in a first travelling direction (forward direction) in all speed ranges, and in the same speed ranges in a second travelling direction opposite to the first one (reverse travelling direction), wherein both travelling directions are to be used equally, special transmissions adjusted to this type of vehicle, especially hydrodynamic transmissions (turbo transmissions), are used in which reversing switching units are integrated. For example, a conventional drive train for a rail vehicle comprises a drive motor, which is also known as the traction motor and is suspended in the vehicle frame and to which the automatic transmission is connected, which provides the same speed ranges and torques for both direction of rotation of the transmission output shaft. Such an automatic transmission therefore differs considerably in respect of its configuration from a commercial vehicle transmission which is used for road vehicles or generally for vehicles which predominantly use a first travelling direction (forward direction) and only rarely use the opposite travelling direction (reverse direction) for reversing for example, wherein the same speed ranges are not available in the opposite travelling direction.

It is further known to provide reversing switching units in rail vehicles in the so-called final drive, i.e. in a gear which is arranged on the axle in the truck, and to transmit drive power which is supplied to the same via a universal shaft, especially a tripod joint shaft extending in the longitudinal direction of the vehicle, from the automatic transmission to the axle extending in the transverse direction of the vehicle or the drive wheels.

The first described embodiment according to the state of the art comes with the disadvantage that special gears such as change-speed gearboxes, and automatic transmissions in particular, need to be used which are frequently more expensive in production due to lower production numbers than comparable change-speed gearboxes for commercial vehicles. The second described embodiment according to the state of the art comes with the disadvantage that the final drive, which is suspended in the especially vibration-loaded region of the truck or the truck frame, has a comparatively large unsprung mass by integration of the reversing switching units, which can lead to vibration problems. Furthermore, it is not possible to use any standard final drives which are free from reversing switching units in this case. DE 198 27 580 A1 describes a reversing gear which is connected on the outside to the final drive and therefore forms a large unsprung mass together with the final drive. As a result, large acceleration forces act on the reversing gear, which in practice repeatedly leads to failures of the reversing gear. The features known from this document are summarized in the preamble of claim 1. DE 857 387 describes a drive train with a reversing gear arranged on the change-speed gearbox housing.

Document DE 969 433 describes a drive forwheelsets of rail vehicles.

The present invention is based on the object of providing a drive train for a vehicle with two equivalent opposite travelling directions, especially for a rail vehicle, which enables the use of simple final drives and change-speed gearboxes, and the latter especially from the field of commercial vehicles, and avoids the disadvantages as explained above.

The object in accordance with the invention will be achieved by a drive train or a reversing gear for such a drive train according to the independent claims. The dependent claims provide advantageous and especially appropriate embodiments of the invention.

The drive train in accordance with the invention comprises a drive motor for driving the vehicle, further a change-speed gearbox for torque conversion or speed conversion. In detail, the change-speed gearbox comprises a change-speed gearbox input shaft and a change-speed gearbox output shaft, and a plurality of switching elements in order to produce various speed ratios between the speed of the change-speed gearbox input shaft and the speed of the change-speed gearbox output shaft. Furthermore, a reversing gear housing is provided which encompasses the switching elements and is penetrated by the change-speed gearbox output shaft or a shaft that is connected to said output shaft for transmitting drive power out of the change-speed gearbox. It is understood that another power output which is in connection or can be brought into connection with the change-speed gearbox output shaft is possible in order to conduct drive power out of the change-speed gearbox housing. The change-speed gearbox output shaft is in drive connection with at least one drive wheel. The change-speed gearbox input shaft is in drive connection with the drive motor, with the change-speed gearbox especially being arranged directly adjacent to the drive motor or being constructionally connected to the same. It is therefore possible to transmit drive power from the drive motor via the change-speed gearbox to the drive wheel and to switch between different speed ratios, which means between different gears in the change-speed gearbox.

The transmission of drive power from the change-speed gearbox to the at least one drive wheel occurs by way of a final drive, especially as explained above. As a result, the final drive is arranged in the drive connection between the change-speed gearbox and the drive wheel.

In accordance with the invention, a separate reversing gear is provided in the drive connection between the change-speed gearbox and the final drive, said reversing gear comprising an input shaft and an output shaft, with the input shaft being in a drive connection with the change-speed gearbox output shaft and the output shaft being in a drive connection with the final drive. As a result, the separate reversing gear is provided in addition to the change-speed gearbox and the final drive and is positioned outside of the change-speed gearbox housing and also outside of a final drive housing, if so provided.

In accordance with an alternative embodiment in accordance with the invention, the separate reversing gear is arranged in the drive connection between the drive motor and the reversing gear, with the input shaft being in a drive connection with the output shaft of the drive motor or being switchable into such a connection, and with the output shaft being in a drive connection with the change-speed gearbox input shaft or being switchable into such a connection. In this case too, the separate reversing gear is provided in addition to the change-speed gearbox and the final drive, and is positioned outside of the change-speed gearbox housing and also outside of a final drive housing, if so provided.

The drive motor advantageously concerns an internal combustion engine such as a diesel engine or any other piston engine. The drive motor comprises an output shaft for example, especially in form of a crankshaft, which is in a drive connection with the change-speed gearbox input shaft, especially connected directly to the same, and which can only be driven in one rotational direction by the drive motor.

In accordance with the invention, the reversing gear is suspended on the change-speed gearbox housing, or it is suspended together with the change-speed gearbox housing on a common frame. It is therefore possible that the reversing gear is suspended in a spring-mounted manner in relation to the final drive or the wheels. This means that considerably lower acceleration forces act on the reversing gear and especially the switching elements contained in said gear. The operational lifespan can be extended considerably in this way and failures can be avoided.

The change-speed gearbox comprises at least one switching element, when a conventional commercial vehicle transmission is used as a change-speed gearbox, e.g. a truck or bus transmission, wherein a passenger car transmission could principally also be used, in order to selectively reverse the direction of rotation of the change-speed gearbox output shaft in relation to the direction of rotation of the change-speed gearbox input shaft. A reverse gear is virtually provided in the change-speed gearbox, or several such reversing gears are provided, which still do not make the reversing travelling direction equivalent to the forward travelling direction. It is obviously not necessary to use this reverse gear by the additionally provided reversing gear, so that measures can be taken in particular which do not allow the engagement of this reverse gear.

In accordance with one embodiment, the separate reversing gear comprises a gear ratio of 1:1, so that the input shaft will always revolve with the same speed as the output shaft (in so far as the drive connection between the input shaft and the output shaft is not interrupted by an optionally provided clutch), either in the same direction of rotation or in the opposite direction of rotation, with the reversal of the direction of rotation being selectively adjustable.

The change-speed gearbox can be arranged as an automatic or semiautomatic gearbox. An arrangement as a manual gearbox is also possible.

The reversing gear comprises switching elements for setting at least three or precisely three switching positions, which is a first switching position in which the output shaft is in a mechanical drive connection with the input shaft of the reversing gear and revolves with the same rotational speed and the same rotational direction as the input shaft, a second switching position in which the output shaft is in a mechanical drive connection with the input shaft and revolves with the same rotational speed but in opposite direction of rotation as the input shaft, and a third switching position in which the mechanical drive connection between the input shaft and the output shaft is interrupted, so that the two shafts are able to revolve at different rotational speeds, or one of the two shafts can be idle while the other shaft revolves. The third switching position can also be designated as the neutral position. When providing a gear ratio in the reversing gear which deviates from 1:1, the input shaft and the output shaft can also revolve at different rotational speeds with respect to one another in the first two switching positions, wherein a fixed gear ratio or reduction ratio is usually provided however.

The input shaft of the reversing gear is advantageously connected directly or directly via a coupling, especially a flexible coupling, to the change-speed gearbox output shaft. As a result, the coupling, especially the elastic coupling, can be the only component in the drive train between the change-speed gearbox output shaft and the input shaft of the reversing gear. It is obviously also possible to integrate parts of the coupling or the entire coupling in one of the two shafts or in both shafts.

The reversing gear is advantageously arranged in the region of the free end of the change-speed gearbox output shaft. In accordance with one embodiment, the reversing gear is especially suspended via its gear housing on the change-speed gearbox housing. In addition or alternatively, the reversing gear can also advantageously be suspended together with the change-speed gearbox housing on the frame, especially via its housing, e.g. the vehicle frame which also carries the coach body. The suspension of the reversing gear on a supporting frame which carries the motor transmission unit is also possible. In accordance with one embodiment, the reversing gear is suspended on the coach body which is usually carried in a vibration-dampened manner and is therefore movable within limits relative to the vehicle frame.

In accordance with one embodiment, the change-speed gearbox is arranged as a so-called differential converter transmission. Such a transmission, which belongs to the automatic transmissions, comprises a hydrodynamic converter, especially a hydrodynamic counter-rotating converter, which is arranged in a first power branch of the change-speed gearbox which is switched in parallel to a second, purely mechanical power branch. In the direction of the drive power flow before these two parallel power branches, a power branch-off is provided in order to selectively supply the drive power introduced into the gear to the two power branches, wherein advantageously simultaneous power transmission is possible via both power branches, i.e. the hydrodynamic power branch (first power branch) and the mechanical power branch (second power branch). In the direction of the drive power flow behind the two parallel power branches, the drive power transmitted via the two power branches will be joined and transmitted together onto the change-speed gearbox output shaft.

If the term of shaft is used here, then said shaft shall not only include solid shafts and shafts whose axial length is larger than their diameter, but any constructional element which is capable of performing a rotational movement and is thereby capable of transmitting drive power or torque such as hollow shafts, drive flanges and the like. A reversing gear in accordance with the invention which can be used in a drive train as described above comprises an input shaft for introducing drive power and an output shaft for conducting out drive power. Furthermore, a gearbox housing is provided which encloses the input shaft and the output shaft at least in part. The gearbox housing can enclose the input shaft and/or the output shaft at least over a partial area of their axial length over the circumference in part or in full.

The reversing gear comprises a planetary gear, having a sun wheel, a ring gear and at least one planet wheel. In this respect, either the ring gear can be used for introducing drive power into the planetary gear, or the sun wheel is used for introducing drive power into the planetary gear. Accordingly, the ring gear is used according to a first embodiment for conducting out drive power from the planetary gear and according to the other embodiment the sun wheel is used.

The gear ratio in the planetary gear is arranged in such a way that the sun wheel and the ring gear revolve with the same speed but in opposite direction of rotation, especially in the case of a fixed planet carrier. As a result, the planetary gear can be used in order to produce the desired reversal in the direction of rotation between the input shaft of the reversing gear and the output shaft of the reversing gear. Alternatively, another fixed gear ratio or reduction ratio can be provided between the sun wheel and the ring gear.

Depending on whether the sun wheel or the ring gear is used for introducing drive power into the planetary gear, either the sun wheel or the ring gear is connected in a torsion-proof manner to the input shaft or is carried in a torsion-proof manner by said shaft when the planetary gear is arranged in the region of the transmission input. Accordingly, the ring gear or the sun wheel is simultaneously connectable in a torsion-proof manner with the output shaft. When the planetary gear is arranged in the region of the transmission output, the wheel (ring gear or sun wheel) which conducts drive power out of the planetary gear is advantageously conversely connected in a torsion-proof manner with the output shaft or is carried in a torsion-proof manner by said output shaft, and the other wheel is connectable in a torsion-proof manner with the input shaft.

Finally, a switching unit is provided in the reversing gear, by means of which a drive connection or a mechanical drive connection can be produced either directly between the input shaft of the output shaft or between one of the two shafts and the sun wheel or the ring gear. The following can be achieved in this manner:

When the sun wheel is used for introducing drive power into the planetary gear and is connected in a torsion-proof manner with the input shaft, the switching unit can be used to either connect the input shaft mechanically to the output shaft, so that the two shafts will revolve with the same rotational speed and in the same direction of rotation, or the ring gear can be connected to the output shaft, so that the output shaft will revolve with the same rotational speed but in the opposite direction of rotation as the input shaft. If according to another embodiment the ring gear is used for introducing drive power into the planetary gear and is connected in a torsion-proof manner to the input shaft, the switching unit can be used to either connect the input shaft mechanically to the output shaft so that both shafts revolve with the same rotational speed and in the same direction of rotation, or the sun wheel can be mechanically connected to the output shaft so that the output shaft will revolve with the same rotational speed as the input shaft but in the opposite direction of rotation.

The switching unit comprises a third switching, which is known as the neutral position and in which the drive connection between the input shaft and the output shaft will be terminated in such a way that there will not be any power transmission between the two shafts anymore and therefore the two shafts are able to revolve at different rotational speeds, or one shaft can be idle while the other shaft will revolve. For this purpose, both the direct drive connection between the two shafts and also the drive connection between one of the two shafts and the sun wheel or the ring gear will be interrupted, depending on whether the sun wheel or the ring gear is connected in a torsion-proof manner to the input shaft.

If a gear ratio between the sun wheel and the ring gear is provided in the planetary gear which deviates from 1:1, the switching unit is advantageously arranged in such a way that it produces the same gear ratio between them during the mechanical connection of the input shaft with the output shaft by means of a mechanical gear step.

Preferably, the switching unit comprises a sliding coupling with a gearing, by means of which a torque-transmitting connection either between the two shafts (input shaft and output shaft) or between one of the two shafts and the sun wheel or the ring gear can be produced by selective displacement of the sliding coupling. When the sun wheel is connected in a torsion-proof manner to the input shaft, a torque-transmitting connection between the ring gear and the output shaft can selectively be produced by means of the sliding coupling, and when the ring gear is connected to the input shaft in a torsion-proof manner, the torque-transmitting connection between the sun wheel and the output shaft can selectively be produced by means of the sliding coupling.

The sliding coupling is advantageously associated with a pressure cylinder for the actuation or displacement thereof, wherein the pressure cylinder can be actuated either pneumatically or hydraulically for example. An electrical, mechanical or electromagnetic actuation of the sliding coupling is also possible.

When the switching unit is positioned in the direction of the power flow from the input shaft to the output shaft before the planetary gear in the reversing gear, either the sun wheel will be selectively connected to the input shaft (if the sun wheel acts as the input for the power flow into the planetary gear), while the ring gear will be connected in a torsion-proof manner to the output shaft or is carried by the same. Alternatively, when the ring gear is used for introducing drive power into the planetary gear, the ring gear will be selectively connected by means of the switching unit to the input shaft, while the sun wheel is connected in a torsion- proof manner to the output shaft or is carried by the same in a torsion-proof manner.

It is understood that other embodiments of the switching unit are possible, e.g. switchable multi-disk clutches.

The input shaft and the output shaft of the reversing gear can advantageously be arranged in alignment or coaxially with respect to each other. According to an alternative embodiment, they are arranged in parallel and not coaxially with respect to each other. Other arrangements are possible.

In accordance with an alternative embodiment in accordance with the invention of a reversing gear for use in a drive train in accordance with the invention, the input shaft and the output shaft revolve with respect to each other at different speeds. Usually, the reversing gear has a fixed gear ratio of the speeds between the input shaft and the output shaft.

The features as illustrated above in connection with the drive train arranged in accordance with the invention can obviously also optionally be provided in a reversing gear in accordance with the invention for use in the aforementioned drive train or any other drive train.

Instead of a reversing gear in planetary configuration, it is also possible to provide a reversing gear with spur gear sets, especially exclusively with spur gear sets. For example, two spur gear trains can be provided which are switched in parallel and of which the one comprises one spur gear step more than the other and of which one can be switched selectively into the drive connection between the reversing gear input shaft and the reversing gear output shaft in order to selectively achieve in this manner the reversal of the direction of rotation of the reversing the output shaft. In particular, a spur gear displaceable in the axial direction is especially provided which can be selectively connected by displacement to the first spur gear train and the second spur gear train.

The invention offers the advantage that since final drives can be arranged in a simpler and lighter way, a lower unsprung mass on the axle is possible in the truck of a rail vehicle. Furthermore, the reversing gear can be positioned in a less vibration-loaded region of the coach body, so that sensitive parts such as the switching unit, sensors etc are subjected to a lower amount of loading.

It is a further advantage that the change-speed gearbox is no longer directly connected to the universal shaft, so that the drive bearing of the change-speed gearbox, especially the automatic gearbox, is relieved and provides longer operational lifespan.

The invention will be explained below by reference to an embodiment.

Fig. 1 shows a drive motor 1 with a change-speed gearbox 2 which is connected thereto. It is obviously also possible to arrange the drive motor 1 separate from the change-speed gearbox 2 and to connect the same via a suitable drive connection to the change-speed gearbox 2. The change-speed gearbox 2 comprises a change-speed gearbox input shaft 2.1 which is driven by the drive motor 1, wherein the output shaft 1.1 of the drive motor 1 is connected directly or optionally in this case via a torsional vibration damper to the change-speed gearbox input shaft 2.1, and a change-speed gearbox output shaft 2.2 on the secondary side of the change-speed gearbox 2. Furthermore, a plurality of switching elements (not shown) are provided in the change-speed gearbox 2 in order to produce different speed or torque ratios between the change-speed gearbox input shaft 2.1 and the change-speed gearbox output shaft 2.2.

The change-speed gearbox input shaft 2.1, the change-speed gearbox output shaft 2.2 and the plurality of switching elements are enclosed by the change-speed gearbox housing 2.3 or are mounted therein. A separate reversing gear 5 is arranged behind the change-speed gearbox 2 as seen in the direction of the drive power flow originating from the drive motor 1.

Said reversing gear 5 comprises an input shaft 5.1 which is connected to the change-speed gearbox output shaft 2.2 either directly or via a coupling 9. The coupling 9 can be arranged as an elastic coupling for example which compensates mounting offsets and/or movements in the axial direction and/or radial direction.

The reversing gear 5 further comprises an output shaft 5.2 which is arranged coaxially in relation to the input shaft 5.1 and is in a drive connection via a universal shaft 10 with a final drive 4 or its final drive input shaft 4.1. If for example the drive engine 1, the change-speed gearbox 2 and the reversing gear 5 are suspended in a rail vehicle in the region of the coach body or on a common frame, the drive power will be transmitted by means of the universal shaft 10 to a truck on which the final drive 4 is suspended or in which the axle 11 is mounted (see the indicated truck frame 12). The axle 11 carries the drive wheels. Only the drive wheel 3 is shown in this case, which is driven by the final drive 4, especially its final drive output shaft 4.2.

Even if not shown in the present case, suitable elastic couplings can be provided in the drive connection between the final drive 4 and the drive wheel 3.

The final drive 4 comprises a separate final drive housing 4.3. As a result, the change-speed gearbox 2, the reversing gear 5 and the final drive 4 are provided as separate gears which are switched in the drive power flow behind one another in series, wherein the change-speed gearbox 2 and the reversing gear 5 are suspended in the present case on a common frame 6, and the final drive 4 is suspended on the truck frame 12 in a relatively movable manner thereto.

The reversing gear 5 comprises a gear housing 5.3 which encloses a planetary gear 7 for producing a reversal in the direction of rotation. The planetary gear 7 comprises a sun wheel 7.1, a ring gear 7.2 and a planet carrier 7.4 which is fixed to the housing. The planet carrier 7.4 rotatably carries at least one planet wheel 7.3, with the illustrated embodiment providing two planet wheels 7.3 on a common shaft in order to provide so-called stepped planetary gears. The two planet wheels 7.3 have different diameters with respect to each other, with the number of teeth of the sun wheel 7.1, the planet wheels 7.3 and the ring gear 7.2 being adjusted to each other in such a way that a mechanical gear ratio with the gear ratio of 1:1 is produced between the sun wheel 7.1 and the ring gear 7.2. It is understood that it would also be possible in a deviating manner to provide a different gear ratio. Advantageously however, the gear ratio between the input shaft 5.1 and the output shaft 5.2 is constant or the same in each drive connection between them. A switching unit 8 comprising a sliding coupling 8.1 by means of which three switching positions A, N and B can be selectively produced is provided in the axial direction behind the planetary gear 7 in the reversing gear 5, in the present case completely within the gear housing 5.3. In the switching position A, which in the present case will be known as the first switching position, the ring gear 7.2 or external gearwheel 13 connected thereto will be coupled mechanically via the internally toothed sliding coupling 8.1 to the output shaft 5.2 or an external gearwheel 14 provided thereon, so that the ring gear 7.2 and the output shaft 5.2 revolve together with each other. At the same time, the drive connection between the input shaft 5.1, or an external gearwheel 15 provided thereon, and the sliding coupling 8.1 will be interrupted. The power flow by the reversing gear 5 therefore occurs from the input shaft 5.1 to the sun wheel 7.1 via the planet wheels 7.3 onto the ring gear 7.2 or the external gearwheel 13 onto the sliding coupling 8.1, and finally via the external gearwheel 14 to the output shaft 5.2.

In the switching position B, which in the present case will be known as the second switching position, the sliding coupling 8.1 connects the output shaft 5.2 or its external gearwheel 14 to the external gearwheel 15 on the input shaft 5.1. The connection between the sliding coupling 8.1 and the ring gear 7.2 or its external gearwheel 13 will be interrupted simultaneously. As a result, the power flow occurs by the reversing gear 5 from the input shaft 5.1 to the sliding coupling 8.1 and then further to the output shaft 5.2.

In the switching position N, which in the present case will be known as the third switching position or neutral position and which is shown in Fig. 1, the drive connection is interrupted between the sliding coupling 8.1 and both the input shaft 5.1 and its external gearwheel 13 and also the ring gear 7.2 or its external gearwheel 15. It is obviously also possible to additionally or alternatively interrupt the drive connection between the sliding coupling 8.1 and the output shaft 5.2 or its output gearwheel 14.

Although the switching unit 8 is shown in the present case in form of an internally toothed sliding coupling 8.1 which cooperates with different external gearwheels, other embodiments with multiple-disk clutches for example are also possible. It is further also possible to arrange the switching unit 8 in power flow before the planetary gear 7. Accordingly, the input shaft 5.1 would then be connectable via the switching unit 8 or its sliding coupling 8.1 in a selective manner to the sun wheel 7.1 or the output shaft 5.2.

Although not shown in Fig. 1, the separate reversing gear 5 could also be positioned in the drive connection between the drive motor 1 and the change-speed gearbox 2.

Claims

1. A propulsion string for a motor vehicle with two equivalent driving directions, in particular a rail vehicle, 1.1 with a drive motor (7) for driving the vehicle; 1.2 with a gear (2), comprising a gear input shaft (2.1) and a gear output shaft (2.2) and several clutch elements to generate different speed ratios between the speed of the gear input shaft (2.1) and the speed of the gear output shaft (2.2); 1.3 having at least one drive wheel (3) which is in contact with the drive motor (1) via the gear (2) or can be coupled to such a connection; 1.4 with an end drive (4) in the drive connection between the gear (2) and the drive wheel (3), through which the drive wheel (3) is supplied with drive power; wherein the 1.5 gear (2) has a gear housing (2.3) which encloses the clutch elements and is penetrated by the gear output shaft (2.2), a shaft connected thereto, or another power output for transferring drive power from the gear housing (2.3); wherein 1.6 a separate reversing gear (5) in the drive connection is provided between the gear (2) and the final drive (4) or between the drive motor (1) and the gear (2) positioned outside the gear housing (2,3) and the final drive (4) and has an input shaft (5.1) and an output shaft (5.2), where 1.7, by placing the separate reversing gear (5) in the drive connection between the gear (2) and the final drive (4), the input shaft (5.1) is in drive communication with the gear output shaft (2.2) or may be coupled to such a connection and the output shaft (5.2) is in drive engagement with the final drive (4) or may be coupled to such connection, or by inserting the reversing gear (5) into the drive connection between the drive motor (1) and the gear (2) input shaft ( 5.1) is in drive communication with a secondary shaft (1.1) in the drive motor (1) or can be coupled to such a connection, and an output shaft (5.2) is in drive communication with the gear input shaft (2.1) or can be coupled to such a connection; characterized in that the 1.8 reversing gear (5) is suspended on the gear housing (2.3) or together with the gear housing (2.3) is suspended on a common frame (6); and the reversing gear (5) has a clutch unit (8) for adjusting at least three or exactly three clutch positions, comprising a first clutch position, wherein the output shaft (5.2) is in mechanical drive communication with the input shaft (5.1) and rotates with the same speed or a different speed and the same direction of rotation as the input shaft (5.1), a second coupling position in which the output shaft (5.2) is in mechanical drive communication with the input shaft (5.1) and rotates at the same or different rotational speed and in the opposite direction of rotation as the input shaft (5.1), and a third coupling position; wherein the mechanical drive connection between the input shaft (5.1) and the output shaft (5.2) is interrupted and the drive motor (1) has a secondary shaft (1.1), in particular in the form of a crankshaft which is in drive communication with the gear shaft (2.1) or can be connected such a connection, and the secondary shaft (1.1) can only be driven in one direction of rotation by the drive motor (1); and that the gear (2) has a clutch member for reversing the direction of rotation of the gear output shaft (2.2) with respect to the gear input shaft (2.1).

Drive string according to one of Claims 1, characterized in that the gear (2) is designed as automatic or automated clutch gear.

Drive string according to one of claims 1 or 2, characterized in that the final drive (4) is enclosed by a final drive housing (4.3) and the reversing gear (5) is positioned outside the final drive housing (4.3).

Reverse gear for use in a drive string according to any one of claims 1 to 3, with an input shaft (5.1) for driving in drive power and an output shaft (5.2) for driving off power: with a gear housing (5.3) which at least partially encloses the input shaft (5.1) and the output shaft (5.2); having a planetary gear (7) comprising a sun wheel (7.1), a hollow wheel (7.2) and at least one planet wheel (7.3), wherein the reaction between the sun wheel (7.1) and the hollow wheel (7.2) is designed in such a way that the sun wheel (7.1) and the hollow wheel (7.2) always rotate at the same speed or speed ratio, but in the opposite direction; the sun wheel (7.1) or the hollow wheel (7.2) is carried pivotally by the input shaft (5.1) or output shaft (5.2) or is pivotally connected thereto, characterized in that a coupling unit (8) is provided by means of which an optional first coupling position, a drive connection can be established either directly or via a mechanical gear stage with the same rotation ratio as the planetary gear (7) between the input shaft (5.1) and the output shaft (5.2) or in a second coupling position between one of the two shafts (5.1,5.2) and the sun gear ( 7.1) or the hollow wheel (7.2).

Reverse gear according to claim 4, characterized in that the clutch unit (8) has a neutral position in which both the direct drive connection between the two shafts (5.1.5.2) and the drive connection between one of the two shafts (5.1,5.2) and the sun gear ( 7.1) or the hollow wheel (7.2) is interrupted so that the drive power flow between the input shaft (5.1) and the output shaft (5.2) is interrupted.

Reverse gear according to one of Claims 4 or 5, characterized in that the coupling unit (8) has a sliding sleeve (8.1) with a tooth, in particular an internal tooth, by means of which, by optional displacement of the sliding sleeve (8.1), a torque transmitting connection is established either between the two shafts (5.1, 5.2) or between one of the two shafts (5.1, 5.2) and the sun wheel (7.1) or the hollow wheel (7.2), where the sliding sleeve (8.1) is connected in particular to a pressure cylinder for displacement thereof.

Reverse gear according to one of claims 4 to 6, characterized in that the input shaft (5.1) and the output shaft (5.2) are arranged parallel and in particular coaxially relative to each other and, in particular, are exclusively housed in the gear housing (5.3).