FR3139610A1 - Gearbox for wheel motor - Google Patents

Abstract

Gearbox (10), in particular gearbox for wheel motor, comprising a housing (12), an output hub (16) supported relative to the housing (12) by at least one bearing (18), an input shaft ( 24) and at least one reduction stage (30A, 30B) configured to rotationally couple the input shaft (24) and the output hub (16) while modifying the torque and speed ratio between the shaft input shaft (24) and the output hub (16), in which the input shaft (24) is supported in rotation by the output hub (16) and the output hub (16) is integral in rotation a satellite carrier (36B) of the at least one reduction stage. Wheel motor and vehicle comprising such a reduction gear. Figure for abstract: Fig. 1

Description

Gearbox for wheel motor

This presentation concerns a reduction gear for a wheel motor, as well as a wheel motor comprising such a reduction gear and a vehicle equipped with such a wheel motor. Such a reduction gear can be used for all types of vehicles, in particular so-called heavy goods vehicles or agricultural or industrial vehicles. Such a gearbox can also be used for other types of wheel motors in which a wheel is directly mounted on the motor which drives it in rotation.

Land vehicles generally include axles which carry wheels and which support the body of the vehicle in relation to the wheels, these axles being driven in rotation by a motor located at a distance from the wheels, via a more or less long and more or less efficient transmission. .

However, there are other solutions, including systems called in-wheel motors. A wheel motor is an assembly in which the motor is associated with the wheel by being mounted on it. The wheel motor therefore provides not only a wheel driving function, but also a mechanical support function for the body of the vehicle in relation to the wheel.

The wheel motor may require a reduction gear, particularly when the wheel motor uses an electric motor: in fact, at its optimal operating point, the electric motor rotates at a speed much higher than that necessary for the wheel. The gearbox then generally turns out to be noisy, which is all the more detrimental as the electric motor is, for its part, relatively silent.

There is therefore a need for a new type of gearbox for in-wheel motors.

For this purpose, the present presentation concerns a reduction gear, in particular a reduction gear for a wheel motor, comprising a casing, an output hub supported relative to the casing by at least one bearing, an input shaft and at least one stage of reduction configured to rotationally couple the input shaft and the output hub while changing the torque and speed ratio between the input shaft and the output hub, in which the input shaft is supported in rotation by the output hub and the output hub is secured in rotation to a planet carrier of the at least one reduction stage.

The axis of the gearbox is the axis of rotation of the output hub. The axial direction corresponds to the direction of the axis of the reducer and a radial direction is a direction perpendicular to this axis and intersecting this axis. Likewise, an axial plane is a plane containing the axis of the gearbox and a radial plane is a plane perpendicular to this axis. A circumference is understood as a circle belonging to a radial plane and whose center belongs to the axis of the gearbox. A tangential or circumferential direction is a direction tangent to a circumference; it is perpendicular to the axis of the gearbox but does not pass through the axis.

Unless otherwise specified, the adjectives interior and exterior are used in reference to a radial direction so that the interior part of an element is, in a radial direction, closer to the axis of the reducer than the exterior part of the same element.

A reduction gear is a device for changing the speed and/or torque ratio between an input shaft and an output hub. For the purposes of this presentation, a gearbox can have a transmission ratio less than one, but also greater than one, depending on what is considered to be the input or output (a gearbox is a generally reversible transmission), in which case we sometimes speaks of a multiplier. As shown, the input shaft is rotatably coupled to the output hub by at least one reduction stage, i.e. there is a functional connection between the input shaft and the output hub. exit.

The at least one reduction stage designates a reduction stage or several reduction stages connected in series with each other, typically with a view to obtaining a higher reduction ratio. For example, the reducer may include two, three or more reduction stages. Subsequently, and unless otherwise indicated, by “one” or “the” reduction stage, we mean “at least one” or “at least one” or even “each” reduction stage. Conversely, the generic use of the plural can include the singular.

According to one example, one, several or all of the reduction stages may comprise an epicyclic gear train. An epicyclic gear train generally has an outer sun gear, also called a ring gear, as well as an inner sun gear, also called a sun gear or sun. The sun gear and the crown are coupled via one or more satellites, the satellites being coupled together by a planet carrier.

In this gearbox, the input shaft is supported in rotation by the output hub. In other words, the input shaft is carried and centered by a bearing provided directly in the output hub, typically a plain bearing.

Thanks to the fact that the input shaft is supported in rotation by the output hub and that the output hub is integral in rotation with the planet carrier, the planet carrier is very well centered in relation to the output shaft. input, which reduces the clearances in the at least one reduction stage and significantly reduces the operating noise of the reducer. The sequence of clearances from one part to another between the input shaft and the output hub, often called a chain of dimensions, is in fact very constrained (and therefore the chain of dimensions very short) due to the fact that the input shaft is supported in rotation by the output hub, and this short chain of dimensions ensures optimal positioning of the components of the at least one reduction stage.

In some embodiments, the input shaft engages an axial bore of the output hub. Optionally, an intermediate bush, fitted between the input shaft and the output hub, can be provided. The bush can facilitate sliding – particularly in rotation – between the input shaft and the output hub.

In certain embodiments, the casing carries a crown of at least one reduction stage. Thus, the crown can be fixed, in particular in the frame of reference of the device to which the gearbox is attached, while the solar and the satellite carrier are mobile in this frame of reference. The crown can be a crown of one of the reduction stages, or even a crown common to several reduction stages.

In these embodiments, the crown (external planetary) is carried by the casing, while the input shaft is carried by the output hub therefore by the reduction gear bearing, which supports the output hub relative to the casing . The chain of dimensions between the input shaft and the crown is therefore very short, because it only passes through the bearing (via the hub). However, the bearing can be very precise, in terms of concentricity and coaxiality, in particular much more precise than gear teeth. The centering precision within the reduction stage is therefore very good. As a result, the gearbox is even quieter.

In some embodiments, the input shaft carries a solar engaged with the at least one reduction stage. The fact that the input shaft carries a sun rather than another pinion makes it possible to maximize the reduction ratio, all things being equal. The compactness of the reducer is also improved.

In some embodiments, the input shaft is rotatably supported by the output hub on one side of the at least one reduction stage, and the input shaft has a drive portion for its driven in rotation by a motor on the other side of the at least one reduction stage. Thus, the output hub and the motor (or the drive part) can be provided on either side of the at least one reduction stage, particularly in the axial direction. The fact that the drive part is not on the side of the output hub, on the one hand, limits the bulk and makes it possible to provide a more compact output hub, which makes the gearbox compatible with smaller wheels, and on the other hand, ensures greater modularity to the gearbox, because the motor and the wheel can be designed much more independently of each other than if they were planned on the same side.

In some embodiments, the drive portion is provided with alignment correction means, such as an Oldham joint or a Cardan joint. The alignment correction means make it possible to avoid a coaxiality or centering constraint on the side of the driving part.

In certain embodiments, the input shaft is movable axially so as to be able to decouple from the at least one reduction stage. Thus, the input shaft is disengageable, said axial movement allowing it to be released from its engagement with the reduction stage or to be engaged again. When the input shaft is disengaged, that is to say decoupled from the at least one reduction stage, the output hub can rotate freely without inducing effort on the motor which drives the output shaft. entrance. Thus, the proposed gearbox is compatible with towing type applications.

In certain embodiments, the input shaft has a driving part configured to be integral in rotation with an external shaft, the driving part being able to slide relative to the external shaft. For example, the drive part can slide in a housing of the external shaft. Thus, the input shaft can remain engaged with the external shaft independent of its coupling with the at least one reduction stage.

In some embodiments, the cross section of the drive portion and the corresponding cross section of the housing are non-circular, and optionally have lobes.

In certain embodiments, the reducer comprises a pin adjoining the input shaft and a cover configured to determine the axial positioning of the pin in order to couple or not the input shaft with the at least one reduction stage . The cover may have a non-symmetrical shape so that its position, for example relative to the hub, determines the position of the pin which, in turn, determines the position of the input shaft.

In some embodiments, a groove is provided on the input shaft, on the output hub or between the input shaft and the output hub, the groove being configured to deliver lubricant to the area where the The input shaft is supported in rotation by the output hub.

In some embodiments, the gearbox further includes a seal between the output hub and the housing, the seal being located radially around the bearing. The seal can help ensure sealing in the gearbox enclosure, particularly when this enclosure is lubricated. The fact that the seal is located radially around the bearing, that is to say not only radially outside the bearing but also opposite the bearing, makes it possible to make the gearbox more axially compact.

The present presentation also relates to a wheel motor comprising a motor and a reduction gear as previously described, the motor being coupled to the input shaft of the reduction gear to drive the input shaft in rotation. In particular, the motor may be an electric motor.

The present presentation also relates to a vehicle comprising a body and wheels, and at least one wheel motor as previously described, the output hub of one of the wheel motors carrying one of the wheels and said wheel motor supporting the body of the vehicle relative to said wheel.

For example, the output hub of the gearbox may include a fixing flange for a drive member such as a rim, a toothed pinion, etc. Furthermore, the casing may include a flange for fixing to a body of the vehicle.

In particular, the reduction gear bearing can be dimensioned not only to ensure rotation of the output hub relative to the casing, but also to take up the load corresponding to a part of the vehicle. In other words, even when the gearbox is not moving, the bearing performs a static holding function. Thus, the wheel motor is capable of ensuring the mechanical function of a conventional half-axle, in addition to being capable of directly driving the wheel.

For example, the gearbox bearing may comprise a plurality of bearings, in particular two bearings, for example conical. Two tapered bearings can be mounted side by side in opposite directions to each other, thus defining an X or O shape, depending on whether the cones are adjacent at their tapered part (><, or of their flared part (<>, or O). The gearbox bearing can assemble the bearings by ensuring preload.

Other characteristics and advantages of the subject of the present presentation will emerge from the following description of embodiments, given by way of non-limiting examples, with reference to the appended figures.

There is a sectional view of a gearbox for a wheel motor according to a first embodiment.

There is a sectional view of a gearbox for a wheel motor according to a second embodiment.

There is a partial sectional view along plane III-III of the .

There is a sectional view of a gearbox for a wheel motor according to a third embodiment.

There is a sectional view of an in-wheel motor according to one embodiment.

There is a perspective view of a vehicle according to one embodiment.

detailed description

There illustrates, in section, a reducer 10 according to a first embodiment. The gearbox 10 comprises a casing 12. The casing 12 can define a fixed part of the gearbox 10. Thus, the casing 12 can be fixed in the frame of reference of the device in which the gearbox 10 is intended to be used.

The casing 12 may have a generally annular shape. The casing 12 can carry a crown 14 forming an external planetary gear for the at least one reduction stage 30A, 30B which will be described later. In this case, the crown 14 can be formed by teeth provided on the interior face of the casing 12.

The reduction gear 10 further comprises an output hub 16, rotatably mounted relative to the casing 12. To do this, in this example, the output hub 16 is supported relative to the casing 12 by at least one bearing 18. In this case, the bearing 18 comprises two conical bearings mounted in opposite directions (known as an X configuration) inside the casing 12 and around the output hub 16. For example, the conical bearings can be preloaded. Typically, after assembly of the conical bearings, an elastic ring can be fitted with a press, so as to ensure the tension of the hub 16. A shim washer can be provided and sized in order to obtain the desired preload.

However, a different type of bearing, a different number of bearings and/or a different assembly of the bearing 18 would be possible, since the chosen bearing 18 is able to take up, alone, the static forces which are exerted between the hub of output 16 and the casing 12. Optionally and as illustrated, the bearing 18 can be pressed against a transverse part of the output hub 16 in order to limit the lever arm acting on the bearing 18.

The rotating output hub 16 defines an axial direction X corresponding to its axis of rotation. The output hub 16 can be generally invariant by rotation around the axial direction X. The casing 12 and the bearing 18 are arranged around the axial direction X.

The interior of the casing 12 defines an enclosure 20 which is closed axially, on one side, by the output hub 16, and on the other side, by a cover 22. The cover 22 is rigidly fixed to the casing 12 and s 'extends here transversely to the axial direction

An input shaft 24 extends at least partly inside the enclosure 20. The input shaft 24 is supported in rotation by the output hub 16. More precisely, the output hub 16 comprises an axial bore 26, in which the input shaft 24 engages. The input shaft 24 itself can extend in the axial direction , the input shaft 24 can be in contact with the bore 26, which ensures the centering of the input shaft 24 relative to the output hub 16.

The enclosure 20 also houses at least one reduction stage configured to couple in rotation the input shaft 24 and the output hub 16 while modifying the torque and speed ratio between the input shaft 24 and the output hub 16. With reference to the , we will describe an embodiment comprising two reduction stages, but the present presentation can apply mutatis mutandis to a single or at least three reduction stages.

Thus, in the present embodiment, the reducer 10 comprises a first reduction stage 30A and a second reduction stage 30B.

The first reduction stage 30A comprises an epicyclic train comprising a solar 32A as well as one or more satellites 34A engaged with the solar 32A and with the crown 14. The satellites 34A are carried by a satellite carrier 36A. The satellites 34A are mounted in rotation relative to the satellite carrier 36A and in revolution relative to the solar 32A.

As indicated previously, in this embodiment, the input shaft 24 carries a solar in engagement with the at least one reduction stage. In this case, the input shaft 24 carries the solar 32A. For example, the solar 32A can be formed by teeth directly machined on the input shaft 24. Alternatively, the solar 32A could be an attached part on the input shaft 24A. The solar 32A can be provided on one side of the input shaft 24 opposite the end engaged in the bore 26 of the output hub 16.

The input shaft 24 forming the input of the reduction gear 10 and the crown 14 being fixed, the output of the first reduction stage 30A is formed by the planet carrier 36A.

The second reduction stage 30B is placed axially between the first reduction stage 30A and the output hub 16. The second reduction stage 30B comprises an epicyclic gear train comprising a solar 32B as well as one or more satellites 34B engaged with the solar 32B and with the crown 14. The satellites 34B are carried by a satellite carrier 36B. The satellites 34B are mounted in rotation relative to the satellite carrier 36B and in revolution relative to the solar 32B.

In this example, the ring 14 is common to the first reduction stage 30A and the second reduction stage 30B. However, in the general case, it is possible to provide distinct crowns, possibly having different pitch radii.

The two reduction stages 30A, 30B are connected in series. Thus, in this example, the input of the second reduction stage 30B, namely the solar 32B, is integral in rotation with the output of the first reduction stage 30A, namely the satellite carrier 36A. The crown 14 being fixed, the output of the second reduction stage 30B is formed by the planet carrier 36B.

Furthermore, the planet carrier 36B is integral in rotation with the output hub 16. In other words, the output hub 16 is integral in rotation with a planet carrier 36B of the at least one reduction stage 30B . For example, the planet carrier 36B can engage in rotation with the output hub 16 by splines or any suitable fitting.

The solar 32B here takes the form of a sleeve coaxial with the input shaft 24. The solar 32B can be adjusted on the input shaft 24 in order to center the second reduction stage 30B on the shaft. input 24, and, via the satellite carrier 36A, the first reduction stage 30A on the input shaft. Alternatively, a clearance can be provided between the solar 32B and the input shaft 24.

For reasons of axial compactness of the reducer 10, the planet carrier 36A of the first reduction stage 30A can abut against the cover 22, the planet carrier 36B of the second reduction stage 30B can abut against the planet carrier 36A of the first reduction stage 30A, and/or the solar 32B can abut against the output hub 16. The transverse surfaces in contact can be configured to reduce the friction and therefore the drag torque within the reducer 10. By example, these surfaces can be planned to be convex and/or of low roughness (not visible on the ) to minimize contact points. Alternatively or in addition, a surface treatment, a coating, a choice of material (for example nitrided steel) or an intermediate part can be provided to reduce friction.

For its rotational drive, the input shaft 24 can comprise a drive part 38 configured to be integral in rotation with an external shaft 40. Optionally, the drive part 38 can be provided with means of correction of alignment 42, in this case a joint of Oldham. The alignment correction means 42 make it possible to authorize a certain lack of coaxiality or centering of the external shaft 40 without harming the potentially very precise centering of the input shaft 24. In addition, the possible bearings 44 which support the external shaft 40 can also be provided with less precision, given that their misalignment with respect to the input shaft 24 is rectified by the alignment correction means 42.

The drive part 38 or the external shaft 40 can extend through an orifice provided in the cover 22. The aforementioned bearings 44 can support the drive part 38 or, as illustrated, the external shaft 40, by relative to the cover 22.

Thus, the input shaft 24 is supported in rotation by the output hub 16 on one side of the at least one reduction stage 30A, 30B (on the left on the ), and the input shaft 24 has a drive part 38 for its rotational drive by a motor on the other side of the at least one reduction stage 30A, 30B (on the right on the ).

The torque which is supplied by a motor to the external shaft 40 is transmitted to the input shaft 24, then, via the solar 32A, to the satellites 34A which drive the satellite carrier 36A in rotation. The satellite carrier 36A, integral in rotation with the solar 32B, in turn drives the satellites 34B which drive the satellite carrier 36B in rotation. The planet carrier 36B is integral in rotation with the output hub 16. Thus, the torque of the external shaft 40 is transmitted to the output hub 16 via the reduction stages 30A, 30B.

Furthermore, the arrangement of the components of the reducer 10 is such that the input shaft 24 is supported in rotation by the output hub 16. In addition, the chain of dimensions between the input shaft 24 and the hub output 16 passes, in parallel, through the two reduction stages 30A, 30B; This results in very good centering of the reduction stages. In addition, the fact that the output hub 16 is supported in rotation relative to the casing 12 on the one hand by the bearing 18 and on the other hand by the satellite 34B in engagement with the crown 14 also ensures very good centering of the reduction stages.

The enclosure 20 can be lubricated to ensure the proper functioning of the gearbox 10. For its sealing, seals can be provided, particularly around the rotating parts. For this purpose, an annular seal 46 can be provided between the cover 22 and the external shaft 40.

Furthermore, the reducer 10 may comprise a seal 48 between the output hub 16 and the casing 12, the seal 48 being located radially around the bearing 18. More precisely, the seal 48, annular, can be mounted on the output hub 16 and present a flexible lip configured to come into contact with the casing 12. The seal 48 can be radially facing the bearing 18, outside of it.

Thus, the enclosure 20 delimited radially by the casing 12 and axially on the one hand by the output hub 16, on the other hand by the cover 22, and by the seals 46, 48 at the interfaces with the rotating parts, is waterproof and can accommodate a given quantity of lubricant. Filling with lubricant can be done in various ways, for example through orifices in the casing 12 which are blocked when the reduction gear 10 is in operation.

To improve the lubrication of the gearbox 10, at least one groove 50 can be provided on the input shaft 24, as illustrated, or on the output hub 16, or between the input shaft 24 and the hub. outlet 16. The groove 50 is configured to bring lubricant to the area where the input shaft 24 is supported in rotation by the output hub 16, that is to say here towards the bore 26. In l In this case, groove 50 is a helical groove. The direction of the helical groove can be chosen so that when the gearbox is operating in the motor direction, the groove 50 conveys lubricant towards the bore 26. These arrangements ensure good lubrication of the area where the input shaft 24 is supported in rotation by the output hub 16.

A collector 52 in communication with the enclosure 20 can be provided in the outlet hub, for example at the bottom of the bore 26. The collector 52 recovers the lubricant conveyed in this case by the groove 50 and distributes it, via transverse channels 54, towards the bearing 18. These arrangements therefore ensure good lubrication of the bearing 18.

Figures 2 to 4 show the reducer in other embodiments. In these figures, the elements corresponding or identical to those of the first embodiment will receive the same reference sign and will not be described again.

In the second embodiment illustrated on the , the input shaft 24 is movable axially so as to be able to decouple from the at least one reduction stage 30A. More precisely, the external shaft 40 and the input shaft 24 fit axially into each other (here the input shaft 24 in a housing 60 of the external shaft 40) so as to be able to slide axially relative to each other. A spring 62 can be mounted between the external shaft 40 and the driving part 38 (or, where appropriate, the alignment correction means 42).

In order to secure the input shaft 24 and the external shaft 40 in rotation, the cross section of the drive part 38 and the corresponding cross section of the housing 60 can be non-circular. There illustrates an example of such a non-circular section of the housing 60: this section comprises a circle 60a at the periphery of which several lobes 60b are arranged, which are themselves circular. The combination of circular shapes makes the housing 60 easy to manufacture by conventional machining tools, while the combined, non-axisymmetric shape ensures reliable rotational connection between the driving part 38 and the external shaft 40.

Furthermore, with reference again to the , the reducer 10 may comprise a pin 64 mounted in an axial bore of the output hub 16. The pin 64 adjoins the input shaft 24 in the axial direction example of O-rings installed in grooves provided on the pin 64. The pin 64 can be protected by a cover 66 fixed to the output hub 16, in this case screwed. The outlet cover 66 may include a boss 68, the interior of which houses the pin 64 which protrudes axially from the outlet hub 16.

In the situation illustrated on the , the input shaft 24 is coupled to the first reduction stage 30A, as has been explained with reference to the . To disengage the input shaft 24, it is possible to disassemble the cover 66, turn it over then attach it again to the output hub 16 in a configuration where the boss 68 projects towards the inside of the output hub 16, or more precisely towards the inside of the bore which houses the pin 64. In doing so, the boss 68 pushes the pin 64 towards the input shaft 24, which is itself pushed further inside the housing 60 of the external shaft 40, against the force exerted by the spring 62. The input shaft 24 is thus translated by a length greater than the engagement length of the solar 32A with the satellite 34A. This axial translation therefore leads to releasing the solar 32A from the satellite 34A, so that the rotation of the input shaft 24 is decoupled from the rotation of the rest of the reduction gear 10, including the reduction stages 30A, 30B and the hub output hub 16. Thus, the output hub 16 can rotate freely, for example for towing, without imposing any effort on the input shaft 24 and therefore on the motor which drives the external shaft 40.

The coupling between the input shaft 24 and the first reduction stage 30A can be restored by reverse manipulation of the cover 66, the spring 62 returning the input shaft 24 to its initial, engaged position, i.e. i.e. engaged with the first 30A reduction stage. An axial stop can be provided to prevent the spring 62 from forcing the input shaft 24 beyond its engaged position, as this would involve forces on the output hub 16.

Thus, the cover 66 determines the positioning, here axial, of the rod 64. In addition, the direction of the cover 66, and particularly the fact that the boss 68 is protruding or recessed, provides a visual indicator to easily know if the input shaft 24 is engaged or disengaged.

Other variants are of course envisaged, for example the fact that the movement of the input shaft 24 decouples the latter not from the first reduction stage 30A, but from its coupling with the input shaft 40. By elsewhere, instead of providing a cover 66 provided with a boss 68, it is possible to provide a cover without boss, provided that the pin 64, the length of which would possibly be adapted, is only inserted when it is desired to disengage the clutch the input shaft 24. According to yet another example, the rod 64 may have ends of different sections, and the input shaft 24 may comprise an internal housing in which only one of the sections of the rod 64 can penetrate. Thus, in one sense, the pin 64 is inserted into the housing without pushing the input shaft 24, while turned over, the pin 64 cannot enter the housing and pushes the input shaft 24. Still other mechanisms can be provided by those skilled in the art to modify the axial position of the input shaft 24.

There illustrates a reducer 10 according to a third embodiment. In this variant of the second embodiment, the drive part 38 is devoid of alignment correction means; however, the drive part 38 takes the form of a toothed wheel configured to cooperate with a corresponding toothed ring in the housing 60. The toothed wheel is provided relatively short in order to allow angular movement making it possible to correct any possible defects. alignment between the input shaft 24 and the external shaft 40. Furthermore, the driving part 38 and the corresponding toothed ring of the housing 60 can comprise between them a clearance making it possible to compensate for possible geometric defects of the components and of their assembly.

Furthermore, the input shaft 24 does not have a lubricant guiding groove 50. In this embodiment, the conduction of the lubricant is facilitated by the fact that the solar 32B of the second reduction stage 30B is separated from the input shaft 24 by a radial clearance (not visible on the ), instead of being exactly centered on the input shaft 24. This radial clearance allows the passage of lubricant.

Furthermore, a sliding sleeve 70 is provided between the bore 26 and the input shaft 24. The sliding sleeve 70 may have tribological characteristics improving the sliding of the input shaft 24 relative to the hub. output 16, without damaging the correct centering of the input shaft 24 relative to the output hub 16.

There illustrates, in longitudinal section, a wheel motor 80 comprising a motor 82 and a reduction gear 10 as previously described, here according to the first embodiment. Motor 82 may be an electric motor. The motor 82 is coupled to the input shaft 24 of the reduction gear 10 to drive the input shaft 24 in rotation. In this case, the motor 82 rotates the external shaft 40 previously described. If necessary, other functions can be added to the wheel motor 80, such as a brake.

There also shows a rim 84 mounted on the output hub 16. In this case, the rim 84 is fixed to the output hub 16, but other assemblies are possible. An annular ring 86 is also provided to assemble with the rim 84. A tire 88 is intended to fit axially between the rim 84 and the ring 86. Such a configuration facilitates the replacement of the tire 88 as well as the rim. 84 is intended to wear. However, other rim configurations are possible and in any case, the output hub 16 can carry something other than a rim and a tire, for example a pinion for driving a caterpillar, a winch, a drilling head, etc.

There illustrates, in perspective, a vehicle 90 comprising a body 92 and wheels 94, and at least one wheel motor 80 as previously described. The output hub 16 of the wheel motor 80 carries a wheel 94 and said wheel motor supports the body 92 of the vehicle relative to said wheel 94. In particular, as detailed previously, the static forces exerted by the body 92 of the vehicle relative to the wheel 94 can be recovered by the bearing 18. Moreover, the shows that the bearing 18 is directly above the rim 84, in this application. In addition, the casing 12 may include one or more flanges 13 for its attachment to the body of the vehicle 92.

Although the vehicle depicted is an automobile, other vehicles are considered, including heavy goods vehicles, industrial or agricultural vehicles, etc.

Although the present description refers to specific embodiments, modifications can be made to these examples without departing from the general scope of the invention as defined by the claims. Furthermore, individual features of the different embodiments illustrated or mentioned may be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than a restrictive sense.

Claims (13)

Gearbox (10), in particular gearbox for a wheel motor, comprising a housing (12), an output hub (16) supported relative to the housing (12) by at least one bearing (18), an input shaft ( 24) and at least one reduction stage (30A, 30B) configured to rotationally couple the input shaft (24) and the output hub (16) while modifying the torque and speed ratio between the shaft input shaft (24) and the output hub (16), in which the input shaft (24) is supported in rotation by the output hub (16) and the output hub (16) is integral in rotation a satellite carrier (36B) of the at least one reduction stage. Reducer according to claim 1, wherein the input shaft (24) engages in an axial bore (26) of the output hub (16). Reducer according to claim 1 or 2, in which the casing (12) carries a crown (14) of the at least one reduction stage (30A, 30B). Reducer according to any one of claims 1 to 3, in which the input shaft (24) carries a solar (32A) in engagement with the at least one reduction stage. Reducer according to any one of claims 1 to 4, in which the input shaft (24) is supported in rotation by the output hub (16) on one side of the at least one reduction stage (30A , 30B), and the input shaft (24) has a drive part (38) for rotating it by a motor (82) on the other side of the at least one reduction stage (30A , 30B). Reducer according to any one of claims 1 to 5, in which the input shaft (24) is movable axially so as to be able to decouple from the at least one reduction stage (30A, 30B). Reducer according to claim 6, in which the input shaft (24) has a driving part (38) configured to be integral in rotation with an external shaft (40), the driving part being capable of sliding in a housing (60) of the external shaft (40). Reducer according to claim 7, wherein the cross section of the driving part (38) and the corresponding cross section of the housing (60) are non-circular, and optionally have lobes (60b). Reducer according to any one of claims 6 to 8, comprising a pin (64) adjoining the input shaft (24) and a cover (66) configured to determine the axial positioning of the pin (64) in order to couple or not the input shaft (24) with the at least one reduction stage (30A, 30B). Reducer according to any one of claims 1 to 9, in which a groove (50) is provided on the input shaft (24), on the output hub (16) or between the input shaft (24 ) and the output hub (16), the groove (50) being configured to supply lubricant to the area where the input shaft (24) is rotatably supported by the output hub (16). Reducer according to any one of claims 1 to 10, further comprising a seal (48) between the output hub (16) and the housing (12), the seal (48) being located radially around the bearing (18). Wheel motor (80) comprising a motor (82), in particular an electric motor, and a reduction gear (10) according to any one of claims 1 to 11, the motor (82) being coupled to the input shaft (24) of the reducer (10) to drive the input shaft (24) in rotation. Vehicle (90) comprising a body (92) and wheels (94), and at least one wheel motor (80) according to claim 12, the output hub (16) of one of the wheel motors (80) carrying one of the wheels (94) and said wheel motor (80) supporting the body (92) of the vehicle relative to said wheel (94).