Patent Description:
This invention finds a preferred, though not exclusive, application in the distribution of torque among axles of a heavy vehicle, such as a lorry. This application will be referred to below by way of example.

Heavy vehicles comprise, as known, a propulsion unit configured to provide torque to one or more of the vehicle's axles. One example of this propulsion unit may be an internal combustion engine, a fuel cell engine, or an electric or hybrid motor unit.

In particular, the torque is distributed via a transmission to one or more axles of the vehicle, as known. In any case, this transmission is specifically designed for an individual traction configuration.

Thus, if you wish to change the traction mode from single or multiple axles, it is necessary to redesign the transmission.

In addition, the current transmissions are particularly bulky and heavy if they need to divide the torque to multiple axles.

Known transmission arrangements are disclosed in publications <CIT>, <CIT> or <CIT>.

The need is, thus, felt to provide a system for distributing torque from one power generator of a vehicle to one or more axles that is versatile, compact, and economical.

The purpose of this invention is to meet the needs outlined above in an optimal and inexpensive way.

The above-mentioned purpose is achieved with a torque distributor system as claimed in the attached claims.

For a better understanding of this invention, a preferred embodiment is described below by way of non-limiting example and with reference to the accompanying drawings, wherein:.

The attached figures schematically illustrate a propulsion unit <NUM> configured to transmit torque through a mechanical chain to multiple axles 2a, 2b, 2c, and 2d of a heavy vehicle (not illustrated), such as a tractor or lorry.

The propulsion unit <NUM> may be an internal combustion engine, a fuel cell system, or a hybrid drive system as known in the art.

The propulsion unit <NUM> is connected to at least one axle via a transmission <NUM>, designed to select a specific gearbox, multiple rotating shafts 4a, 4b, 4c, 4d, and a torque distributor system <NUM> according to the invention.

<FIG> and <FIG> illustrate a configuration with two driving axles 4a, 4b where the torque distributor <NUM> is connected by a first rotating shaft 4a to the propulsion unit <NUM>, in the case described via the transmission <NUM>, and where a first axle 4a is connected by a second rotating shaft 4b.

Referring to <FIG>, the torque distributor <NUM> comprises a casing <NUM> designed to be supported by a portion fixed to the vehicle's chassis (not illustrated) defining a space <NUM> and a transmission assembly <NUM> housed inside the space <NUM>.

Clearly, the casing <NUM> is advantageously constructed from several parts firmly connected together in order to enable the assembly of the transmission assembly <NUM> in the space <NUM>.

The casing <NUM> defines multiple openings <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> configured to enable the passage of respective power take-offs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> as better described below, connected together by the transmission <NUM>.

More specifically, the distributor system <NUM> defines six openings and respective power take-offs, preferably in pairs coaxial between them. In particular, the first and second opening <NUM>, <NUM> and the first and second power take-off <NUM>, <NUM> are coaxial to an axis A, the third and the fourth openings <NUM>, <NUM> and the third and fourth power take-offs <NUM>, <NUM> are coaxial to an axis B and the fifth and the sixth openings <NUM>, <NUM> and the fifth and sixth power take-offs <NUM>, <NUM> are coaxial to an axis C.

The axes A, B, and C are, advantageously, parallel to each other and, even more preferably, are parallel to a longitudinal axis of the vehicle.

In the embodiment in <FIG>, where there are two drive axles, two power take-offs <NUM>, <NUM> communicate with the external environment while four power take-offs <NUM>, <NUM>, <NUM>, <NUM> are separate from the external environment via covers 21a, 21b, 21c, 21d fixed to the casing <NUM> via connection means <NUM>, such as threaded parts.

In particular, in the embodiment described, the rotating shaft 4a is connected to the power take-off <NUM>, and the power take-off <NUM> is connected to the axle 2a and to the axle 2b, as described below, via the transmission <NUM>.

The transmission <NUM> essentially comprises a first support shaft <NUM> connected to the first power take-off <NUM>, in the case described firmly fixed to it; this first support shaft <NUM> is connected via a first differential mechanism <NUM> to a second support shaft <NUM>. The support shaft <NUM>, in the case described, is firmly fixed to the second power take-off <NUM>.

The first support shaft <NUM> is also operationally connected to the fifth and to the sixth power take-off <NUM>, <NUM> via a second differential mechanism <NUM>. In particular, the first support shaft <NUM> is connected to the second differential mechanism <NUM> via a reduction module <NUM>.

Specifically, the reduction module <NUM> comprises a rotating shaft <NUM> supported rotationally free by the casing <NUM> and advantageously connected to the third and fourth power take-offs <NUM>, <NUM>, for example firmly connected to them. The rotating shaft <NUM> supports at least one toothed wheel <NUM>, in the case described a toothed wheel <NUM> configured to mesh with the first and second differential mechanism <NUM>, <NUM>.

More specifically, the first differential mechanism <NUM> comprises a gear train <NUM> configured to connect together multiple planet gears <NUM> meshing between a pair of gear hubs <NUM>', <NUM>", respectively left and right. In particular, the gear hubs <NUM>', <NUM>'' are cone gear hubs.

Specifically, the left gear hub <NUM>' is connected integrally with the rotation of the support shaft <NUM> and is configured to also define an additional toothing <NUM> configured to cooperate with the reduction module <NUM>, i.e., with the toothed wheel <NUM> described above.

The right gear hub <NUM>" is, instead, advantageously, firmly connected to the second support shaft <NUM> and, thus, second power take-off <NUM>.

Referring to the second differential mechanism <NUM>, it comprises a gear train <NUM> operationally connected to the sixth power take-off <NUM>, supported rotationally free by the casing <NUM>, and configured to drag multiple planet gears <NUM> meshing with a pair of hubs <NUM>', <NUM>", respectively left and right. In particular, the gear hubs <NUM>', <NUM>" are cone gear hubs and, preferably, the sixth power take-off <NUM> is firmly carried by the gear train <NUM>.

In particular, the right hub <NUM>" is connected to a connecting shaft <NUM> configured to be connected with the rotating shaft 4b to bring the torque to the axle 4b via the fifth power take-off <NUM>. In particular, the connecting shaft <NUM> is housed inside the differential mechanism <NUM>, i.e., it passes coaxially to the rotation axis of the planet gears <NUM>.

On the other hand, the left hub <NUM>' is firmly connected to a connecting shaft <NUM> configured to be connected with the axle 4a.

In particular, the connection of the shaft <NUM> (and, similarly, even if not illustrated of the shaft <NUM>) is made via a gear <NUM> between the connecting shaft <NUM> and the semiaxes (not visible) of the axle 2a. In the particular case illustrated, the gear <NUM> comprising a first toothed wheel <NUM>' firmly connected to the connecting shaft <NUM> and a second toothed wheel <NUM>'' operationally connected to the semiaxes of the axle 2a. Advantageously, these toothed wheels <NUM>', <NUM>" are conical toothed wheels.

The connecting shaft <NUM> is preferably coaxial and supported by the casing <NUM> around the connecting shaft <NUM> of the right hub <NUM>".

The transmission <NUM> also comprises locking means <NUM> configured to lock the first or second differential mechanism <NUM>, <NUM>. In particular, the locking means <NUM> are housed in the space <NUM>.

To greatly summarise, the locking means <NUM> comprise a sleeve <NUM> driven by actuator means <NUM> and configured to cooperate in contact with a differential element <NUM>, <NUM> to lock the operation thereof, i.e., to make each of its elements rotate at the same speed.

In the embodiment illustrated, the locking means <NUM> for the first differential mechanism <NUM> comprise a sleeve <NUM> that can move so as to assume a first condition in which it does not cooperate with the gear train <NUM> and a second condition in which it cooperates with the gear train <NUM> to make it selectively integral with the casing.

Instead, the locking means <NUM> for the second differential mechanism <NUM> comprise a sleeve <NUM> that can move so as to assume a first condition in which it does not cooperate with the gear train <NUM> but cooperates, integrally with the rotation with the left hub <NUM>' and a second condition in which it cooperates with the gear train <NUM> to make it selectively integral with the rotation with the left hub <NUM>'.

The actuator means <NUM> illustrated here are advantageously pneumatic, i.e., they comprise a piston that can be driven with compressed air and kept in the position to unlock the differential via elastic means, which are not described further for the sake of brevity.

In the embodiment of <FIG> and <FIG>, the vehicle comprises three driving axles 2a, 2b, and 2c. As a result, in relation to the embodiment in <FIG> and <FIG>, the sixth power take-off <NUM> is connected to a third rotating shaft 4c that connects the transmission <NUM> to the third axle 2c. The third rotating shaft 4c can be connected with the semiaxes of the third axle 2c using a gear similar to the gear <NUM> described above.

In the embodiment of <FIG> and <FIG>, the vehicle comprises four driving axles 2a, 2b, 2c, and 2d. As a result, in relation to the embodiment in <FIG> and <FIG>, the sixth power take-off <NUM> is connected to a third rotating shaft 4c that connects the transmission <NUM> to the third axle 2c and the second power take-off <NUM> is connected to a fourth rotating shaft 4d that connects the transmission <NUM> to the fourth axle 2d. The third and fourth rotating shafts 4c, 4d can be connected with the semiaxes of the third and fourth axles 2c, 2d using corresponding gears similar to the gear <NUM> described above.

In all three embodiments, the third and fourth power take-offs <NUM>, <NUM> can be used for other purposes, like the connection of electric machines (not illustrated) that could be connected directly to the casing <NUM> or via a gear to the above-mentioned power take-offs <NUM>, <NUM> to provide additional torque or generate electricity. Equally, the third and fourth power take-offs <NUM>, could be connected to devices designed to use the drive torque for other purposes, such as support equipment for the vehicle's operation, such as hydraulic pumps or motors.

The operation of the embodiments described above is as follows.

In the embodiment in <FIG> and <FIG>, the torque generated by the power generator <NUM> is transmitted through the rotating shaft 4a to the first power take-off <NUM> to the first support shaft <NUM>. Here, the torque passes to the reduction module <NUM> and is transferred to the second differential mechanism <NUM>. The first support shaft <NUM> also provides torque to the first differential mechanism that rotates idly. In particular, the torque is transferred between the toothing <NUM> and the toothed wheel <NUM>, which meshes with the gear train <NUM> and rotates it. The gear train <NUM> drags the planet gears <NUM> that rotate the hubs <NUM>' and <NUM>" that rotate the corresponding connecting shafts <NUM> and <NUM>. These latter rotate, via corresponding gears <NUM>, the semiaxes of the first and second axles 2a, 2b. The gear train <NUM> and the shaft <NUM>, rotating, bring with them the respective power take-offs <NUM>, <NUM>, and <NUM> that rotate idly. Thanks to the differential mechanism <NUM>, the connecting shafts <NUM>, <NUM> may have different rotation speeds compared to each other.

If necessary, the locking means <NUM> may be activated to lock the gear train <NUM>, and, thus, the sixth power take-off <NUM>, compared to the left hub <NUM>'. In this way, both the connecting shafts <NUM>, <NUM> rotate at the same speed, dragging, without differences in speed, the semiaxes of the axles 2a, 2b.

In the embodiment in <FIG> and <FIG>, the sixth power take-off is connected via the third rotating shaft 4c to a third driving axle 2c and the torque provided according to what was discussed beforehand to the gear train <NUM> is provided to the semiaxes of the third axle 2c. If the locking means <NUM> lock the gear train <NUM> to the left hub <NUM>', all three connecting shafts would rotate at the same speed.

In the embodiment in <FIG> and <FIG>, the sixth power take-off is connected via the third rotating shaft 4c to a third driving axle 2c and the torque provided according to what was discussed beforehand to the gear train <NUM> is provided to the semiaxes of the third axle 2c. If the locking means <NUM> lock the gear train <NUM> to the left hub <NUM>', all three connecting shafts 4a, 4b, 4c would rotate at the same speed. In addition, the second power take-off is connected via the fourth rotating shaft 4d to a fourth driving axle 2d that rotates, thanks to the first differential mechanism <NUM> at a different speed compared to that of the other rotating shafts 4a, 4b, 4c. In this case too, the locking means <NUM> may be activated to firmly attach the gear train <NUM> to the casing <NUM> so as to have the same torque at output towards the second differential mechanism <NUM> and towards the fourth rotating shaft 2d. Arranging, as a result, the relationships between the reduction module <NUM> and the second differential mechanism <NUM>, it is possible to rotate, if both the locking means are activated, at the same speed.

In all the embodiments, part of the torque may be used connecting the third and/or fourth power take-off <NUM>, <NUM> to a system using the vehicular torque for other purposes. Similarly, the third and/or fourth power take-off <NUM>, <NUM> could be connected to electric machines and/or other systems that use or provide torque to interact with the transmission <NUM>.

From the above, the advantages of a torque distributor system according to the invention are clear.

The distributor system proposed makes it possible to distribute, in a versatile way, to different axles of a vehicle, making it possible to obtain different vehicle driving axle configurations with the same system.

In addition, the distributor system proposed makes it possible to connect electric machines for additional support/use of the torque provided by the power generator, or devices to use this torque to the same system.

Thus, the distributor system according to the invention is particularly versatile, i.e., it is suitable for a large variety of purposes, reducing the costs of manufacturing and enabling a lot of vehicle customisation.

In addition, the fact that the transmission is housed inside a single space and the fact that the power take-offs can be isolated when not used, increases the service life of the transmission.

The use of more differentials also makes it possible to have axles with equal traction that can be used in the conditions required by specific loading and/or ground situations.

Finally, it is clear that changes may be made to the torque distributor system, and variations produced thereto, according to this invention that, in any case, do not depart from the scope of protection defined by the claims.

Clearly, additional mechanical elements not described for brevity may be included.

Claim 1:
A torque distributor system (<NUM>) for distributing the torque coming from a power generator (<NUM>) of a vehicle to a plurality of axles (2a, 2b, 2c, 2d) of said vehicle,
said distributor system (<NUM>) comprising a casing (<NUM>) adapted to define a space (<NUM>) configured to house a transmission (<NUM>), said casing (<NUM>) defining a plurality of openings (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) configured to house respective power take offs (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) connected to each other by said transmission (<NUM>), a first power take off (<NUM>) of said power take offs <NUM>, <NUM>, <NUM> , <NUM>, <NUM>, <NUM>) being connectable to said power generator (<NUM>) and at least a second (<NUM>) of said power take-offs (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) being connectable to one or more of said axles (2a, 2b, 2c, 2d), wherein said transmission (<NUM>) comprises a differential mechanism (<NUM>) operatively interposed between said first and said second power take-off (<NUM>, <NUM>), said second power take-off (<NUM>) comprising a pair of connecting shafts (<NUM>, <NUM>) connected to respective outputs of said differential mechanism (<NUM>),
said system comprising a third power take-off (<NUM>) connectable to a third axle (2c) of said vehicle, said third power take-off (<NUM>) being operatively connected to a gear train (<NUM>) of said mechanism differential (<NUM>) and a fourth power take-off (<NUM>), said transmission (<NUM>) comprising a further differential mechanism (<NUM>) operatively interposed between said first and fourth power take-offs (<NUM>, <NUM>).