Gearbox for wheel motor

Abstract

Gearbox (10), in particular a 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 changing the torque and speed ratio between the input shaft (24) and the output hub (16), wherein the input shaft (24) is rotationally supported by the output hub (16), and the output hub (16) is rotationally fixed to a planet carrier (36B) of the at least one reduction stage. Wheel motor and vehicle comprising such a gearbox. Figure for the abbreviation: Fig. 1

Description

Title of the invention: Gearbox for wheel motor technical field

[0001] The present description relates to a gear reducer for a wheel motor, as well as a wheel motor comprising such a gear reducer and a vehicle equipped with such a wheel motor. Such a gear reducer can be used for all types of vehicles, including heavy goods vehicles, agricultural vehicles, and industrial vehicles. Such a gear reducer can also be used for other types of wheel motors in which a wheel is directly mounted on the motor, which drives its rotation. Previous technique

[0002] Land vehicles generally include axles which carry wheels and which support the body of the vehicle relative to the wheels, these axles being driven in rotation by a motor located at a distance from the wheels, via a transmission which is more or less long and more or less efficient.

[0003] However, other solutions exist, including systems called wheel motors. A wheel motor is an assembly in which the motor is connected to the wheel by being mounted on it. The wheel motor therefore provides not only a drive function for the wheel, but also a mechanical support function for the vehicle body relative to the wheel.

[0004] The wheel motor may require a gearbox, particularly when the wheel motor uses an electric motor: indeed, at its optimal operating point, the electric motor rotates at a speed much higher than that required by the wheel. The gearbox then generally proves to be noisy, which is all the more detrimental since the electric motor itself is relatively quiet.

[0005] There is therefore a need for a new type of wheel motor reducer. Description of the invention

[0006] For this purpose, the present description relates to a reducer, in particular a reducer for wheel motor, comprising a housing, an output hub supported relative to the housing by at least one bearing, an input shaft and at least one reduction stage configured to couple in rotation 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 rotationally fixed to a planet carrier of the at least one reduction stage.

[0007] The axis of rotation of the output hub is called the axis of the reducer. The axial direction corresponds to the direction of the axis of the reducer, and a radial direction is a direction perpendicular to and intersecting this axis. Similarly, an axial plane is a plane Containing the axis of the reducer and a radial plane, a plane is a plane perpendicular to that axis. A circumference is understood as a circle belonging to a radial plane and whose center lies on the axis of the reducer. A tangential or circumferential direction is a direction tangent to a circumference; it is perpendicular to the axis of the reducer but does not pass through the axis.

[0008] Unless otherwise specified, the adjectives inside and outside are used with reference to a radial direction so that the inside part of an element is, along a radial direction, closer to the axis of the reducer than the outside part of the same element.

[0009] A gearbox is a device that allows the speed and / or torque ratio between an input shaft and an output hub to be changed. For the purposes of this description, a gearbox can have a transmission ratio less than one, but also greater than one, depending on whether the input or output is considered (a gearbox is generally a reversible transmission), in which case it is sometimes called a multiplier. As indicated, the input shaft is rotationally coupled to the output hub by at least one reduction stage; that is, there is a functional connection between the input shaft and the output hub.

[0010] At least one reduction stage refers to one or more reduction stages connected in series, typically to achieve a higher reduction ratio. For example, the reducer may comprise two, three, or more reduction stages. Hereafter, unless otherwise specified, "one" or "1" reduction stage means "at least one" or "each" reduction stage. Conversely, the generic use of the plural may include the singular.

[0011] By way of example, one, several, or all of the reduction stages may include an epicyclic gear train. An epicyclic gear train generally has an outer planet gear, also called the ring gear, and an inner planet gear, also called the sun gear. The planet gear and the ring gear are coupled via one or more planet gears, the planet gears being coupled to each other by a planet carrier.

[0012] In the present reducer, the input shaft is supported in rotation by the output hub. In other words, the input shaft is supported and centered by a bearing formed directly in the output hub, typically a plain bearing.

[0013] Thanks to the fact that the input shaft is supported in rotation by the output hub and that the output hub is rotationally fixed to the planet carrier, the planet carrier is very well centered with respect to the input shaft, which reduces backlash in at least one reduction stage and significantly reduces the operating noise of the gearbox. The chain of backlashes from one part to the next between the input shaft and the output hub, often called the tolerance chain, is indeed very constrained (and therefore the (very short dimension chain) because the input shaft is supported in rotation by the output hub, and this short dimension chain ensures optimal positioning of the components of at least one reduction stage.

[0014] In certain embodiments, the input shaft engages in an axial bore of the output hub. Optionally, an intermediate sleeve, fitted between the input shaft and the output hub, may be provided. The sleeve can facilitate sliding—particularly rotational sliding—between the input shaft and the output hub.

[0015] In certain embodiments, the housing carries a ring for at least one reduction stage. Thus, the ring may be fixed, particularly in the frame of reference of the device to which the reducer is attached, while the solar array and the satellite carrier are movable in this frame of reference. The ring may be a ring for one of the reduction stages, or even a ring common to several reduction stages.

[0016] In these embodiments, the ring gear (outer planetary gear) is supported by the housing, while the input shaft is supported by the output hub and therefore by the gearbox bearing, which supports the output hub relative to the housing. The dimensional chain between the input shaft and the ring gear is thus very short, as it passes only through the bearing (via the hub). The bearing can be very precise in terms of concentricity and coaxiality, in particular much more precise than gear teeth. The centering accuracy within the reduction stage is therefore very good. Consequently, the gearbox is even quieter.

[0017] In some embodiments, the input shaft carries a solar gear meshed with at least one reduction stage. The fact that the input shaft carries a solar gear rather than another pinion maximizes the reduction ratio, all other things being equal. The compactness of the gearbox is also improved.

[0018] In certain embodiments, the input shaft is supported in rotation by the output hub on one side of at least one reduction stage, and the input shaft has a drive portion for its rotational drive by a motor on the other side of at least one reduction stage. Thus, the output hub and the motor (or the drive portion) can be located on either side of at least one reduction stage, particularly in the axial direction. The fact that the drive portion is not on the same side as the output hub, on the one hand, reduces the overall size and allows for a more compact output hub, making the gearbox compatible with smaller wheels, and on the other hand, ensures greater modularity for the gearbox, since the motor and the wheel can be designed much more independently of each other than if they were located on the same side.

[0019] In certain embodiments, the drive part is equipped with alignment correction means, such as an Oldham joint or a Cardan joint. The alignment correction means make it possible to avoid coaxiality stress or centering on the side of the training part.

[0020] In certain embodiments, the input shaft is axially movable so as to be able to disengage from at least one reduction stage. Thus, the input shaft can be disengaged, this axial movement allowing it to be released from its engagement with the reduction stage or re-engaged. When the input shaft is disengaged, that is, decoupled from at least one reduction stage, the output hub can rotate freely without inducing any force on the motor that drives the input shaft. Thus, the proposed gearbox is compatible with towing applications.

[0021] In certain embodiments, the input shaft has a drive portion configured to be rotationally fixed to an external shaft, the drive portion being able to slide relative to the external shaft. For example, the drive portion can slide within a housing in the external shaft. Thus, the input shaft can remain meshed with the external shaft independently of its coupling to at least one reduction stage.

[0022] In some embodiments, the cross-section of the drive part and the corresponding cross-section of the housing are non-circular, and optionally have lobes.

[0023] In certain embodiments, the reducer includes a pin adjacent to 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 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.

[0024] 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 bring lubricant to the area where the input shaft is supported in rotation by the output hub.

[0025] In certain embodiments, the gearbox further comprises a seal between the output hub and the housing, the seal being located radially around the bearing. The seal can help ensure sealing within the gearbox enclosure, particularly when this enclosure is lubricated. The fact that the seal is located radially around the bearing, that is, not only radially outside the bearing but also opposite the bearing, makes the gearbox more axially compact.

[0026] The present description also relates to a wheel motor comprising a motor and a gearbox as previously described, the motor being coupled to the input shaft of the gearbox to drive the input shaft in rotation. In particular, the motor may be an electric motor.

[0027] The present description 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 vehicle body relative to said wheel.

[0028] For example, the output hub of the reducer may include a mounting flange for a drive element such as a rim, a toothed pinion, etc. Furthermore, the housing may include a mounting flange for attaching to a vehicle body.

[0029] In particular, the gearbox bearing can be dimensioned not only to ensure the rotation of the output hub relative to the housing, but also to support 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 performing the mechanical function of a conventional half-axle, in addition to being capable of directly driving the wheel.

[0030] For example, the gearbox housing may comprise a plurality of bearings, in particular two bearings, for example tapered roller bearings. Two tapered roller bearings may be mounted side by side in opposite directions, thus defining an X or O shape, depending on whether the cones are adjacent at their narrowed (x, or X) or flared (<>, or O) portion. The gearbox housing may assemble the bearings by providing a preload. Brief description of the drawings

[0031] Other features and advantages of the subject matter of this presentation will become apparent from the following description of embodiments, given by way of non-limiting examples, with reference to the attached figures.

[0032] Fig. 1 is a cross-sectional view of a wheel motor reducer according to a first embodiment.

[0033] Fig. 2 is a cross-sectional view of a wheel motor reducer according to a second embodiment.

[0034] The [Fig.3] is a partial sectional view along plane 111-111 of the [Fig.2].

[0035] Fig. 4 is a cross-sectional view of a wheel motor reducer according to a third method of implementation.

[0036] Fig. 5 is a cross-sectional view of a wheel motor according to one embodiment.

[0037] Fig. 6 is a perspective view of a vehicle according to one embodiment. Detailed description

[0038] Figure 1 illustrates, in cross-section, a reducer 10 according to a first embodiment. The reducer 10 comprises a housing 12. The housing 12 can define a fixed part of the reducer 10. Thus, the housing 12 can be fixed in the frame of reference of the device in which the reducer 10 is intended to be used.

[0039] The housing 12 may have a generally annular shape. The housing 12 may carry a ring gear 14 forming an external planetary gear for at least one reduction stage 30A, 30B, which will be described later. In this case, the ring gear 14 can be formed by teeth provided on the inner face of the housing 12.

[0040] The reducer 10 also includes an output hub 16, rotatably mounted relative to the housing 12. To this end, in this example, the output hub 16 is supported relative to the housing 12 by at least one bearing 18. In this case, the bearing 18 comprises two tapered roller bearings mounted in opposite directions (an X-configuration) inside the housing 12 and around the output hub 16. For example, the tapered roller bearings may be preloaded. Typically, after mounting the tapered roller bearings, a spring ring may be press-fitted to ensure tension on the hub 16. A shim washer may be provided and sized to obtain the desired preload.

[0041] However, a different type of bearing, a different number of bearings and / or a different mounting of the bearing 18 would be conceivable, provided that the chosen bearing 18 is capable of alone taking up the static forces exerted between the output hub 16 and the housing 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 exerted on the bearing 18.

[0042] The rotating output hub 16 defines an axial direction X corresponding to its axis of rotation. The output hub 16 can be globally invariant under rotation about the axial direction X. The housing 12 and the bearing 18 are arranged about the axial direction X.

[0043] The interior of the housing 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 housing 12 and extends here transversely to the axial direction X.

[0044] An input shaft 24 extends at least partially inside the housing 20. The input shaft 24 is supported in rotation by the output hub 16. More specifically, the output hub 16 has an axial bore 26 into which the input shaft 24 engages. The input shaft 24 itself can extend along the axial direction X. As illustrated in [Fig. 1], 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.

[0045] The enclosure 20 also houses at least one reduction stage configured to couple the input shaft 24 and the output hub 16 in rotation while changing the torque and speed ratio between the input shaft 24 and the output hub 16. With reference to [Fig.1], an embodiment comprising two reduction stages will be described, but the present description can be applied mutatis mutandis to one or at least three reduction stages.

[0046] Thus, in the present embodiment, the reducer 10 comprises a first reduction stage 30A and a second reduction stage 30B.

[0047] The first reduction stage 30A comprises an epicyclic gear train including a solar element 32A and one or more satellite elements 34A meshed with the solar element 32A and with the ring gear 14. The satellite elements 34A are carried by a satellite carrier 36A. The satellite elements 34A are mounted in rotation relative to the satellite carrier 36A and in revolution relative to the solar element 32A.

[0048] As previously stated, in this embodiment, the input shaft 24 carries a solar element meshing with at least one reduction stage. In this case, the input shaft 24 carries the solar element 32A. For example, the solar element 32A can be formed by teeth machined directly onto the input shaft 24. Alternatively, the solar element 32A could be an added component on the input shaft 24A. The solar element 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.

[0049] The input shaft 24 forming the input of the reducer 10 and the ring 14 being fixed, the output of the first reduction stage 30A is formed by the planet carrier 36A.

[0050] The second reduction stage 30B is positioned axially between the first reduction stage 30A and the output hub 16. The second reduction stage 30B comprises an epicyclic gear train including a solar element 32B and one or more satellite elements 34B meshed with the solar element 32B and with the ring gear 14. The satellite elements 34B are carried by a satellite carrier 36B. The satellite elements 34B are mounted for rotation relative to the satellite carrier 36B and for revolution relative to the solar element 32B.

[0051] 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 separate rings, possibly having different pitch radii.

[0052] 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 element 32B, is rotationally fixed to the output of the first reduction stage 30A, namely the satellite carrier 36A. Since the ring 14 is fixed, the output of the second reduction stage 30B is formed by the satellite carrier 36B.

[0053] Furthermore, the satellite carrier 36B is rotationally fixed to the output hub 16. In In other words, the output hub 16 is rotationally fixed to a planet carrier 36B of at least one reduction stage 30B. For example, the planet carrier 36B can engage in rotation with the output hub 16 by means of splines or any suitable interlocking.

[0054] The solar element 32B here takes the form of a coaxial sleeve to the input shaft 24. The solar element 32B can be adjusted on the input shaft 24 to center the second reduction stage 30B on the input shaft 24, and, via the planet carrier 36A, the first reduction stage 30A on the input shaft. Alternatively, a gap can be provided between the solar 32B and input shaft 24.

[0055] For reasons of axial compactness of the gearbox 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 element 32B can abut against the output hub 16. The transverse contact surfaces can be configured to reduce friction and therefore the drag torque within the gearbox 10. For example, these surfaces can be convex and / or have low roughness (not visible in [Fig. 1]) to minimize the contact points. Alternatively or in addition, a surface treatment, a coating, a choice of material (e.g., nitrided steel), or an intermediate part can be provided to reduce friction.

[0056] For its rotational drive, the input shaft 24 may include a drive portion 38 configured to be rotationally fixed to an external shaft 40. Optionally, the drive portion 38 may be equipped with alignment correction means 42, in this case an Oldham joint. The alignment correction means 42 allow a certain degree of coaxiality or centering of the external shaft 40 without compromising the potentially very precise centering of the input shaft 24. Furthermore, any bearings 44 that support the external shaft 40 may also be provided with less precision, since their misalignment with respect to the input shaft 24 is corrected by the alignment correction means 42.

[0057] The drive part 38 or the external shaft 40 can extend through an opening provided in the cover 22. The aforementioned bearings 44 can support the drive part 38 or, as illustrated, the external shaft 40, relative to the cover 22.

[0058] Thus, the input shaft 24 is supported in rotation by the output hub 16 on one side of at least one reduction stage 30A, 30B (on the left in [Fig.l]), and the input shaft 24 has a drive part 38 for its drive in rotation by a motor on the other side of at least one reduction stage 30A, 30B (on the right in [Fig.l]).

[0059] The torque supplied by a motor to the external shaft 40 is transmitted to the input shaft 24, then, via the solar element 32A, to the satellites 34A which drive the satellite carrier 36A in rotation. The satellite carrier 36A, fixed in rotation to the solar element 32B, in turn drives the satellites 34B which drive the satellite carrier 36B in rotation. The satellite carrier 36B is fixed in rotation to the output hub 16. Thus, the torque from the external shaft 40 is transmitted to the output hub 16 via the reduction stages 30A, 30B.

[0060] 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 output hub 16 pass parallel to each other through the two reduction stages 30A and 30B; this results in very good centering of the reduction stages. Furthermore, the fact that the output hub 16 is supported in rotation relative to the housing 12 by the bearing 18 on one side and by the planet gear 34B meshing with the ring gear 14 on the other also ensures very good centering of the reduction stages.

[0061] The housing 20 can be lubricated to ensure the proper functioning of the reducer 10. Seals can be provided for its sealing, particularly around the rotating parts. For this purpose, an annular seal 46 can be provided between the cover 22 and the external shaft 40.

[0062] Furthermore, the reducer 10 may include a seal 48 between the output hub 16 and the housing 12, the seal 48 being located radially around the bearing 18. More specifically, the annular seal 48 may be mounted on the output hub 16 and have a flexible lip configured to come into contact with the housing 12. The seal 48 may be radially opposite the bearing 18, outside of it.

[0063] Thus, the enclosure 20, radially delimited by the housing 12 and axially bounded on one side by the output hub 16, on the other by the cover 22, and by the seals 46, 48 at the interfaces with the rotating parts, is sealed and can hold a given quantity of lubricant. Lubricant can be added in various ways, for example through openings in the housing 12 which are closed when the gearbox 10 is in operation.

[0064] 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 even between the input shaft 24 and the output hub 16. The groove 50 is configured to supply lubricant to the area where the input shaft 24 is supported in rotation by the output hub 16, i.e., here towards the bore 26. In this case, the groove 50 is a helical groove. The direction of the helical groove can be chosen so that, when the gearbox is operating in the drive direction, the groove 50 carries 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.

[0065] A collector 52 in communication with the enclosure 20 can be provided in the output 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, to the bearing 18. These arrangements therefore ensure good lubrication of the bearing 18.

[0066] Figures 2 to 4 show the reducer in other embodiments. In these figures, elements corresponding to or identical to those of the first embodiment will be given the same reference numeral and will not be described again.

[0067] In the second embodiment illustrated in [Fig. 2], the input tree 24 is axially movable so as to be able to decouple from at least one reduction stage 30A. More precisely, the external shaft 40 and the input shaft 24 fit axially into one another (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 drive part 38 (or, where applicable, the alignment correction means 42).

[0068] In order to lock the input shaft 24 and the external shaft 40 together for rotation, the cross-section of the drive portion 38 and the corresponding cross-section of the housing 60 may be non-circular. Figure 3 illustrates an example of such a non-circular cross-section of the housing 60: this cross-section comprises a circle 60a around the periphery of which are arranged several circular lobes 60b. The combination of circular shapes makes the housing 60 easy to manufacture using conventional machining tools, while the combined, non-axisymmetric shape ensures reliable rotational locking between the drive portion 38 and the external shaft 40.

[0069] Furthermore, with reference again to [Fig. 2], the reducer 10 may include a pin 64 mounted in an axial bore of the output hub 16. The pin 64 is adjacent to the input shaft 24 in the axial direction X. The pin 64 may be fitted with seals, for example O-rings installed in grooves provided on the pin 64. The pin 64 may be protected by a cover 66 fixed to the output hub 16, in this case screwed on. The output cover 66 may include a boss 68, the interior of which houses the pin 64, which protrudes axially from the output hub 16.

[0070] In the situation illustrated in [Fig. 2], the input shaft 24 is coupled to the first reduction stage 30A, as explained with reference to [Fig. 1]. To disengage the input shaft 24, the cover 66 can be removed, turned over, and then reattached to the output hub 16 in a configuration where the boss 68 protrudes inward from the output hub 16, or more precisely, into the bore that houses the pin 64. In doing so, the boss 68 pushes the pin 64 toward the input shaft 24, which is itself pushed further into 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 element 32A with the satellite element 34A.This axial translation therefore leads to the solar 32A being detached from the satellite 34A, so that the rotation of the input shaft 24 is decoupled from the rotation of the rest of the reducer 10, including the reduction stages 30A, 30B and the output hub 16. Thus, the output hub 16 can rotate freely, for example for towing, without imposing any force on the input shaft 24 and therefore on the motor which drives the external shaft 40.

[0071] The coupling between the input shaft 24 and the first reduction stage 30A can be restored by a reverse manipulation of the cover 66, the spring 62 returning the shaft input 24 towards its initial, engaged position, i.e. in contact with the first reduction stage 30A. An axial stop can be provided to prevent the spring 62 from forcing the input shaft 24 beyond its engaged position, as this would imply forces on the output hub 16.

[0072] Thus, the hood 66 determines the positioning, here axial, of the pin 64. In addition, the direction of the hood 66, and particularly the fact that the boss 68 is protruding or recessed, provides a visual indicator to easily know whether the input shaft 24 is engaged or disengaged.

[0073] 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. Furthermore, instead of providing a cover 66 with a boss 68, it is possible to provide a cover without a boss, provided that the pin 64, the length of which could possibly be adapted, is only inserted when it is desired to disengage the input shaft 24. According to yet another example, the pin 64 may have ends of different cross-sections, and the input shaft 24 may include an internal housing into which only one of the cross-sections of the pin 64 can enter. Thus, in one direction, the pin 64 inserts into the housing without pushing the entry shaft 24, while reversed, the pin 64 cannot enter the housing and pushes the entry shaft 24.Other mechanisms can be devised by a person skilled in the art to modify the axial position of the input shaft 24.

[0074] Figure 4 illustrates a reducer 10 according to a third embodiment. In this variant of the second embodiment, the drive portion 38 lacks alignment correction means; however, the drive portion 38 takes the form of a gear configured to cooperate with a corresponding toothed ring in the housing 60. The gear is provided to be relatively short to allow angular travel enabling correction of any misalignment between the input shaft 24 and the external shaft 40. Furthermore, the drive portion 38 and the corresponding toothed ring in the housing 60 may have clearance between them to compensate for any geometric defects in the components and their assembly.

[0075] Furthermore, the input shaft 24 is devoid of a lubricant guide groove 50. In this embodiment, lubricant flow is facilitated by the fact that the solar element 32B of the second reduction stage 30B is separated from the input shaft 24 by a radial clearance (not visible in [Fig. 4]), instead of being exactly centered on the input shaft 24. This radial clearance allows the passage of lubricant.

[0076] 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 output hub 16, without deteriorating the proper centering of the input shaft 24 relative to the output hub 16.

[0077] Figure 5 illustrates, in longitudinal section, a wheel motor 80 comprising a motor 82 and a gearbox 10 as previously described, here according to the first embodiment. The motor 82 may be an electric motor. The motor 82 is coupled to the input shaft 24 of the gearbox 10 to drive the input shaft 24 in rotation. In this case, the motor 82 drives the external shaft 40 described previously in rotation. If necessary, other functions may be added to the wheel motor 80, such as a brake.

[0078] Figure 5 also shows a rim 84 mounted on the output hub 16. In this instance, the rim 84 is fixed to the output hub 16, but other mountings are possible. An annular flange 86 is also provided for assembly with the rim 84. A tire 88 is designed to fit axially between the rim 84 and the flange 86. This configuration facilitates the replacement of the tire 88 that the rim 84 is designed to carry. However, other configurations without the rim are possible, and in any case, the output hub 16 can carry something other than a rim and a tire, for example, a sprocket for driving a track, a winch, a drill head, etc.

[0079] Figure 6 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 vehicle body 92 relative to said wheel 94. In particular, as detailed previously, the static forces exerted by the vehicle body 92 relative to the wheel 94 can be absorbed by the bearing 18. Moreover, Figure 5 shows that the bearing 18 is aligned with the rim 84 in this application. Furthermore, the housing 12 may include one or more flanges 13 for its attachment to the vehicle body 92.

[0080] Although the vehicle represented is a car, other vehicles are envisaged, including heavy goods vehicles, industrial or agricultural vehicles, etc.

[0081] Although the present description refers to specific embodiments, modifications may be made to these examples without departing from the general scope of the invention as defined by the claims. Furthermore, individual features of the various 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

Demands

1. Gear reducer (10) for wheel motor for vehicle, the gear reducer (10) comprising a housing (12), an output hub (16) supported relative to the housing (12) by at least one bearing (18) capable of supporting the load corresponding to a part of the vehicle, an input shaft (24) and at least one reduction stage (30A, 30B) configured to couple in rotation the input shaft (24) and the output hub (16) while changing the torque and speed ratio between the 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 rotationally fixed to a planet carrier (36B) of the at least one reduction stage.

2. Reducer according to claim 1, in which the input shaft (24) engages in an axial bore (26) of the output hub (16).

3. Reducer according to claim 1 or 2, in which the housing (12) carries a ring (14) of at least one reduction stage (30A, 30B).

4. Reducer according to any one of claims 1 to 3, wherein the input shaft (24) carries a solar (32A) meshed with at least one reduction stage.

5. Reducer according to any one of claims 1 to 4, wherein the input shaft (24) is supported in rotation by the output hub (16) on one side of at least one reduction stage (30A, 30B), and the input shaft (24) has a drive part (38) for its drive in rotation by a motor (82) on the other side of at least one reduction stage (30A, 30B).

6. Reducer according to any one of claims 1 to 5, wherein the input shaft (24) is axially movable so as to be able to decouple from at least one reduction stage (30A, 30B).

7. Reducer according to claim 6, in which the input shaft (24) has a drive part (38) configured to be rotationally fixed to an external shaft (40), the drive part being able to slide in a housing (60) of the external shaft (40).

8. Reducer according to claim 7, wherein the cross-section of the drive part (38) and the corresponding cross-section of the housing (60) are non-circular, and optionally have lobes (60b).

9. Reducer according to any one of claims 6 to 8, comprising a pin (64) adjoining the input shaft (24) and a hood (66) configured to determine the axial positioning of the pin (64) in order to couple or not the input shaft (24) with at least one reduction stage (30A, 30B).

10. Reducer according to any one of claims 1 to 9, wherein 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 bring lubricant to the area where the input shaft (24) is supported in rotation by the output hub (16).

11. 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).

12. Wheel motor (80) comprising a motor (82), in particular an electric motor, and a reducer (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.

13. 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).

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