FR2701429A1 - Wheel device and automotive vehicle including such a device - Google Patents

Abstract

The present invention relates to a wheel device as well as to an automotive vehicle including at least one wheel device of this type. A wheel (13) includes a hub (19) capable of being driven in rotation, in a controlled fashion, about a main shaft (14) relative to a support (8) and itself peripherally carrying a plurality of rollers (28) mounted so they can rotate freely about respective secondary shafts (24) relative to the hub (19) and capable of being immobilised in a controlled fashion against such a rotation. The wheel (13), via these rollers (26), comes into contact with the surface over which the wheel is to travel. Omnidirectional automotive vehicles capable of being immobilised in a controlled fashion can be produced with the aid of such wheel devices.

Description

 The present invention relates to a wheel device, of the type comprising a wheel support and a wheel itself comprising a hub rotatably mounted on the support around a predetermined main axis, the hub being inscribed in a cylindrical geometric envelope of revolution around the main axis, and a plurality of rollers mounted free to rotate on the hub around a respective respective secondary axis, situated in a plane perpendicular to the main axis, the rollers having a respective periphery of revolution around the respective secondary axis, which periphery matches said envelope, and being distributed around the main axis so that their peripheries succeed one another on the envelope, in the circumferential direction.

 In the most widespread embodiments of a device of this type, each roller is permanently free to rotate around the respective secondary axis relative to the hub, itself permanently free to rotate around the main axis in relation to the support.

 Several devices of this type are generally used, as described for example in Canadian patent N0 475 792, for equipping a handling trolley intended to operate on a substantially flat and substantially horizontal area, by securing each wheel support with this trolley of such so that the main axes have respective directions fixed relative to the carriage, parallel to the circulation area and perpendicular to the same proper direction of the carriage, which defines a main direction of rolling of the latter on the area, by rotation of each hub around the respective main axis with respect to the corresponding support, without rotation of the rollers around the secondary axes with respect to the hubs; the carriage can however roll in any other direction over the area, with or without rotation of the hubs around the main axes relative to the supports but with rotation of the rollers around the secondary axes relative to the hubs.

 Carriages are thus produced which can be pushed or pulled in all directions over the area, although mounting the supports without the possibility of orienting the main axes relative to the carriage results in both great simplicity and robustness compatible with handling heavy loads.

 However, especially in the case of such loads, devices of this type have the disadvantage of a certain difficulty in controlling the movements of the assembly formed by the carriage and its load, and in particular to follow a determined trajectory with a determined orientation of the assembly formed by the carriage and its load with respect to the trajectory.

 This drawback, already significant in the case of a flat and horizontal area, becomes critical in the case of an area with a certain surface irregularity or a slope; in the latter case, there may be a difficulty linked to the weight of the assembly formed by the carriage and the load, to which it may be difficult to make the slope climb or descend under suitable conditions of comfort and safety.

 Also known, from American patents Nos. 3,295,700, 3,789,947 and 4,237,990 and international application WO 86 103132, self-propelled vehicles equipped with several, in particular three, wheel devices of the type indicated in the preamble, including each further comprises drive motor means controlled from the hub to rotate about the respective main axis relative to the support; the main axes contribute to each other, in the same plane arranged substantially parallel to the evolution area, and the drive means respectively associated with the different wheel devices are controlled independently of each other, which makes it possible to steer the vehicles by modulating the respective rotational speeds and the respective stops of the different hubs, and to stop the vehicles by stopping the different hubs with respect to their support although each roller remains free to rotate on the respective hub.

 These vehicles have the advantage of being able to follow in a motorized manner any desired trajectory on the evolution area and of being able to be stopped thereon in any desired position, but this possibility is tied to a precise relative positioning of the main axes, which restricts your possibilities of application, as well as a great complexity of order.

 Finally, US Patent No. 3,789,947 describes wheel devices of the type indicated in the preamble, except that the rollers are provided with respective motor means, designed to selectively drive that of these rollers which is at a given instant. in contact with the area of evolution.

 Such a motorization of the rollers, in particular when it accompanies a motorization of the hub, makes it possible to ensure motorization of the movements of a vehicle in all directions of the area of evolution, but it is particularly complex and costly; it is also cumbersome, in particular at the level of the wheel proper, and can only relate to vehicle wheels intended to move without constraint of space.

 The object of the present invention is to remedy these drawbacks and, to this end, the present invention provides a device of the type indicated in the preamble, furthermore provided with drive motor means controlling the hub in rotation about the axis. main relative to the support and characterized in that it comprises means of controlled immobilization of each roller against a rotation about the respective secondary axis relative to the hub.

A person skilled in the art will readily understand that if a vehicle, such as a trolley, is fitted with at least one device according to the invention, by mounting the support thereof so that the main axis has a fixed direction with respect to the vehicle and parallel to an area on which it is intended to roll, it is possible to produce a self-propelled vehicle whose area, respectively each area, provided with such a device
- if each roller is immobilized against a rotation about the respective secondary axis relative to the hub and if the operation of the driving means is caused, can roll in a motorized manner following a determined trajectory, locally perpendicular to the direction of the main axis, without the need for auxiliary guidance,
- if each roller is released vis-à-vis a rotation about the respective secondary axis relative to the hub, can also roll in a motorized manner, under the action of the driving means, along a trajectory which diverges from the trajectory determined above, on condition that a guidance is applied to the vehicle transversely to this trajectory, that is to say in the direction of the main axis, either manually or by means of guidance means such as slides, specifically provided on the area, or to move motorized, in particular by means of wheel devices according to the invention, other areas of the vehicle so that the latter, considered as a whole , accomplish a determined trajectory,
- If each roller is immobilized against a rotation about the respective secondary axis relative to the hub and the hub itself relative to the support, either simply by stopping the drive means, suitably chosen for this effect, either by stopping the drive means and by actuating specific means of controlled immobilization of the hub against a rotation about the main axis relative to the support, is immobilized on the area completely, except at against a pivoting around an axis perpendicular thereto and passing through the point of contact of the wheel with it, which pivoting can in particular be applied in a motorized manner to the vehicle by a motorized displacement of other zones of that here, for example also provided with wheel devices according to the invention,
- if each roller is left free to rotate around the respective secondary axis by immobilizing the hub relative to the support, can be moved without motorization, that is to say under the action of a push or pull suitably oriented, or a suitable motorized drive from other areas of the vehicle, for example also fitted with wheel devices according to the invention, along a path locally parallel to the main axis.

 It is thus possible to equip a vehicle with a single device according to the invention, the support of which is carried by a frame of the vehicle and the main axis of which has a fixed direction relative to the latter, this frame being moreover provided with load-bearing wheels whose axes are generally fixed with respect to it and parallel to the main axis of the device according to the invention, or even to equip a vehicle with several devices according to the invention, and possibly exclusively of devices according to the invention, of which the supports are carried and connected to each other by a frame of the vehicle and the main axes of which have fixed directions relative to the frame and perpendicular to the same proper direction thereof, for example according to the teachings of the aforementioned Canadian patent.

 The wheel support, respectively each wheel support, is then preferably constituted by a member for suspending the frame of the vehicle, and for example by an arm articulated on the frame around an axis of articulation parallel to the 'main axis and associated with elastic biasing means at pivoting, about this articulation axis, relative to the frame, in a direction corresponding to a distance from the main axis relative to the frame; preferably, controlled means are provided for adjusting a limit orientation of the arm around the axis of articulation relative to the frame, corresponding to a maximum approach of the main axis relative to the frame and to a stress maximum of the elastic biasing means.

 In a particularly advantageous manner, the drive means can then comprise a controlled propulsion engine housed in the frame of the vehicle and connected to the hub of the wheel device according to the invention, respectively to the respective hub of several wheel devices according to the invention, by kinematic connection means housed at least partially in the suspension member such as an arm, which makes it possible to limit the size and the mass of the or each wheel device proper; the preferred use of a controlled propulsion motor common to several wheel devices according to the invention, with kinematic connection between the motor and each of the hubs by means allowing a differential speed of rotation between the latter , allows to lighten and simplify the vehicle as a whole without affecting its handling.

 It thus becomes possible to handle even heavy and bulky loads on possibly irregular and sloping areas, benefiting on the one hand from the motorization and on the other hand from the possibility of following a determined trajectory, if necessary after having oriented properly the vehicle ; in particular, it is possible to easily cross a slope, under the action of the driving means and while each roller is immobilized against a rotation about the respective secondary axis relative to the hub, on condition that have oriented the vehicle beforehand so that the direction of the main axis is perpendicular or approximately perpendicular to the line of greatest slope.

 In addition, by using at least one wheel device according to the invention, it is possible to produce a self-propelled vehicle capable of moving autonomously along a complex trajectory, alternating generally rectilinear sections which the vehicle can cross while each roller is immobilized. against a rotation around the respective secondary axis relative to the hub, without it being necessary to provide for this purpose means for guiding the vehicle, and sections of more or less pronounced curvature, that the vehicle crosses while the rollers are free to rotate around the respective secondary axis relative to the hub and being guided laterally, for example by pressing against slides bordering these sections of trajectory.

 When a vehicle is exclusively equipped with devices according to the invention, the main axes of which have directions perpendicular to the same proper direction of the frame of the vehicle, the latter benefits from a possibility of motorized movement, with total grip, in all directions not perpendicular to the proper direction of its frame, and if necessary of a possibility of non-motorized movement perpendicular to this proper direction.

 Naturally, provision can also be made to use devices according to the invention in place of known devices, on other types of known vehicles, for example on the vehicles described in American patents Nos. 3,295,700 and 4,237,990 Appropriate control of the driving or stopping of the different hubs as well as of the braking or of the release of the different rollers then makes it possible to combine the respective displacements of the respectively corresponding zones of the vehicle to ensure motorized displacement of the latter in any direction of the area of evolution, or a total immobilization of the vehicle.

 The use of a device according to the invention thus makes it possible to create self-propelled vehicles offering quite interesting possibilities, although this device is both much less expensive and much less bulky than the motorized roller device described in the US Patent No. 3,789,947. Due to the possibility of producing it in a small footprint, the wheel device according to the invention can be integrated into small vehicles, and for example be used to constitute the undercarriage of pipeline exploration vehicles.

For this purpose, it is possible to produce a vehicle whose framework comprises
- two load-bearing modules, mutually juxtaposed longitudinally,
means of mutual articulation of the two load-bearing modules around a determined longitudinal axis, for example in the form of a central module, interposed longitudinally between the load-bearing modules and on which each of the latter is articulated around said longitudinal axis,
means for relative angular positioning of the carrier modules around said longitudinal axis, in particular in the form of respective controlled means for angular positioning of each of them with respect to the central module, around said longitudinal axis,
and each bearing module of which carries the respective supports of at least three wheel devices according to the invention, angularly distributed around said longitudinal axis, namely preferably three of these devices regularly distributed around this axis and mutually identical, the means of 'controlled immobilization of the rollers of the wheel arrangements of one of the carrier modules with respect to their hub being independent of the controlled immobilization means of the rollers of the wheel devices of the other carrier module with respect to their hub.

 Although very simple, favorable in terms of cost as in terms of reliability, such a vehicle offers great adaptability in particular with a view to avoiding obstacles which could hinder its progress in a pipeline, such as tappings, manholes or thermowells, by twisting around the longitudinal axis and selective immobilization, alternating, of the rollers of the wheel devices of one or the other carrier module.

 It also lends itself to an embodiment of the framework in a small footprint, in particular transverse, favorable to an introduction into the pipes by an orifice of reduced size and to progression in sinuous pipes, with pronounced curvature, while offering a possibility of adapting to pipelines with very different sections, not only close to this transverse size but also much greater than this, or even sections varying in large proportions as it progresses, more particularly when, according to a preferred embodiment, the wheel support of each wheel device according to the invention is constituted by a suspension arm articulated on the corresponding carrier module around an axis parallel to the main axis and pivotally biased around this axis of articulation, relative to the bearing module in question, in a direction corresponding to a distance from the main axis relative to the frame, namely in this case relative to the longitudinal axis thereof.

 Preferably, in such a case, the arms corresponding to each carrier module are oriented, from the respective axis of articulation on the corresponding carrier module, in the longitudinal direction of a distance from the other carrier module and diverge mutually in this direction, this deployment orientation of the arms being the orientation that they occupy in particular during the longitudinal progression of the vehicle in a pipeline; it is understood that from this deployment orientation, the arms can be folded towards the longitudinal axis of the frame, around the respective axis of articulation, to also occupy a folding position in which the vehicle has its minimum transverse dimensions, in particular to allow its introduction into a pipeline or its extraction out of such a pipeline through an orifice as small as possible thereof.

This makes it possible to limit the overall longitudinal and transverse dimensions of the vehicle practically to those of the frame, by folding the arms along the latter, with a view to its storage and its handling and in particular when it is a question of introduce it into a pipe or extract it, and nevertheless give the arms a length, measured between the articulation axis and the main axis, as large as possible in comparison with the longitudinal dimension of the framework , in order to be able to adapt the overall transverse dimensions of the vehicle to pipe sections much greater than the overall transverse dimensions of the frame, by transverse deployment of the arms.

 Advantageously, the respective axes of articulation of the arms on the respective corresponding carrier module are located in the same. respective transverse plane, perpendicular to the longitudinal axis, and the arms as well as the wheels are respectively mutually identical; the orientation of the vehicle around its longitudinal axis is then indifferent. With a view to adapting the arms deployed to very different pipe sections, in particular much greater than the overall transverse dimensions of the vehicle when the arms are folded, each carrier module preferably further comprises controlled means, common to the corresponding wheel devices, for adjusting the same limit orientation of the arms of the latter around the respective axis of articulation, with respect to this module, this limit orientation corresponding to an approximation maximum of the main axis relative to the longitudinal axis and a maximum stress of the respective means of elastic stress; an independence of the carrier modules in this respect facilitates the operations of disengaging the vehicle if one of the wheels comes into contact with an obstacle, for example to accidentally engage in a tapping; for the same purpose, each module preferably comprises its own controlled propulsion motor, common to the corresponding wheel devices.

 Naturally, as in a certain number of previously known embodiments of wheel devices of the type indicated in the preamble, the secondary axes of the rollers whose peripheries succeed one another on the casing are preferably located respectively on either side of the wheel. 'a mean plane perpendicular to the main axis, which avoids any interruption between the rollers in the circumferential direction of the hub.

With a view to achieving the controlled immobilization means of each roller against rotation about the respective secondary axis relative to the hub, provision is advantageously made for the latter to have a passage arranged along the main axis and having a branch opposite each roller, in a respective direction at least approximately radial with respect to the main axis and with respect to the respective secondary axis. This makes it possible to produce in a particularly simple manner the immobilization means controlled under a form comprising
inside each branching of the passage, a respective braking piston guided in translation in the respective direction relative to the hub and having a tail projecting towards the main axis, inside the passage,
- inside the passage, a drawer guided in translation controlled along the main axis relative to the hub and having a periphery cooperating with the tails of the pistons so that, when the drawer occupies a determined position along the main axis relative to the hub, each piston is applied firmly against the periphery of the respective roller and immobilizes the latter relative to the hub and that, when the slide valve occupies another determined position along the main axis relative to the hub, each piston is released towards the main axis relative to the periphery of the respective roller.

 Under these conditions, an appropriate displacement of the slide along the main axis, inside the passage of the hub, is coercively accompanied by the application of each piston against the periphery of the respective associated roller, and consequently ensures the braking of particularly efficient and reliable.

 The release of the rollers with respect to a rotation about the respective secondary axis relative to the hub when braking has to stop is preferably facilitated by the elastic return means of each piston towards the main axis.

 It is optionally possible for the drawer to be movable in rotation about the main axis, relative to the support, jointly with the hub, but the control of the drawer in translation along the main axis relative to the hub can be perform using simpler means, carried by the support, if the drawer is fixed in rotation about the main axis relative to the support, in which case its periphery has a shape of revolution around the main axis.

 In addition, it is advantageously provided that the periphery of each roller has a sliding coefficient favorable to its adhesion to a rolling area, taking into account the driving nature of the wheel device according to the invention, on the one hand, and to make it more effective immobilization of the rollers with respect to a rotation about the respective secondary axis relative to the hub, by application of the aforementioned pistons. For example, for this purpose, the periphery of each roller is elastically compressible, each roller can be produced for example by affixing a layer of a material having the elasticity of rubber, to constitute its periphery, on a mounting core to rotation about the respective secondary axis relative to the hub.

 Other characteristics and advantages of a wheel device according to the invention, as well as of a self-propelled vehicle according to the invention, will emerge from the description below, relating to a nonlimiting exemplary embodiment, as well as from the drawings. attached which form an integral part of this description.

- Figure 1 shows a schematic view of a self-propelled vehicle provided with wheel devices according to the invention, essentially in side elevation in a direction coinciding with the direction, common, of the main axes of these devices.

- Figure 2 shows a similar view of one of these wheel devices, after removal of a protective casing.

- Figure 3 shows a view of the same device, in section through two half-planes identified in III-III in Figure 2, and illustrates part of the drive motor means controlled from the hub to rotation around the main eu in relation to the support.

- Figure 4 shows a schematic perspective view of the motor drive means controlled by the hub of each wheel device around the corresponding main axis.

- Figure 5 shows a view of the assembly formed by a hub and by the rollers which it carries, essentially in side elevation in accordance with Figures 1 and 2 and partly in section through a plane perpendicular to the axis main and marked in VV in Figure 3.

- Figure 6 shows a view of the same wheel device, in side elevation in the same direction as in Figures 1, 2, 5 but in the opposite direction, after removal of a protective casing.

- Figure 7 shows a view of the device in section along the two half-planes identified in III-III in Figure 2, and illustrates the controlled immobilization means of each roller against a rotation around the respective secondary axis with respect to the hub.

FIG. 8 shows a schematic view, in side elevation, of another self-propelled vehicle provided with wheel devices according to the invention, intended for exploring pipelines and comprising for this purpose two extreme load-bearing modules provided with such devices and mutually connected by a central section with respect to which these two load-bearing modules can rotate around the same determined longitudinal axis; only two wheel devices according to the invention, for example six in number, have been illustrated for reasons of clarity, namely on the left, in a limit folding position, for storage, handling, introduction into the pipes through an orifice thereof or extraction from the pipes through such an orifice, and to the right in a limit deployment position, for the path of a pipe.

- Figure 9 shows a front view of this exploration vehicle, while the wheel devices are deployed for such a route.

- Figure 10 shows a schematic perspective view of the rotation mechanism of one of the carrier modules around the longitudinal axis relative to the central module.

- Figure 11 shows a partial view, in section through a plane passing through the longitudinal axis, of one of the carrier modules and more particularly shows the means for adjusting the limit orientation of the arms forming in this case the supports of the wheels in the direction of approximation of the corresponding main axis with respect to the longitudinal axis of the vehicle.

FIG. 12 shows a view of these means in section through a transverse plane marked in XII-XII in FIG. 11.

FIG. 13 shows a view of means for detecting the effective orientation and of this limit orientation of one of the arms, in section through a longitudinal plane marked in XIII-XIII in FIG. 11.

Illustrated in FIG. 1, as a first non-limiting example of a self-propelled vehicle capable of being fitted with wheel devices according to the invention, a handling trolley 1, intended to roll over an approximately flat area or surface 2 and approximately horizontal, possibly sloping, for example in a workshop,
- either in a self-directed manner, in a straight line in one or the other of two mutually opposite directions 3, 4 in a longitudinal direction 5 parallel to the surface 2, at the place where the vehicle 1 is located, and parallel to a mean longitudinal axis 6 thereof,
- Either manually guided, by transverse thrusts, or by means of lateral slides or similar devices known to a person skilled in the art, along a trajectory not parallel to the mean longitudinal axis 6 and for example curvilinear, or else straight but oblique to axis 6.

 The vehicle 1 is for example equipped with four wheel devices 7 according to the invention, corresponding by mutual symmetry on the one hand with respect to an average longitudinal plane not referenced, perpendicular to the surface 2 and including the axis 6, and on the other hand with respect to a mean transverse plane also not referenced, perpendicular to the axis 6. One could however provide other relative arrangements, and different numbers of wheel devices according to the invention for a vehicle, depending the nature of this vehicle and the geometrical conformation of the area on which it must operate. Similarly, the same vehicle could comprise at least one wheel device according to the invention combined with wheel devices of other types and , in particular, the vehicle 1 illustrated in FIG. 1 could be equipped with two wheel devices 7 according to the invention, which will now be described, and with at least one other wheel device co designed and mounted in any similar way, but devoid of means of controlled immobilization of each roller against rotation about the respective secondary axis relative to the hub as well as motor drive means controlled hub for rotation about the main axis with respect to the corresponding support.

 The vehicle 1 illustrated in FIG. 1 being suspended to make its bearing compatible with possible irregularities on the surface 2, each wheel device 7 according to the invention comprises in the example illustrated in particular in FIGS. 1, 2, 6 a support 8 in the form of an arm, oriented approximately longitudinally and comprising a first end 9 articulated on a frame 10 of the vehicle 1, around an axis 11 perpendicular to the mean longitudinal plane thereof, and a second end 12, in the form of a yoke , carrying a wheel 13 which will be described later, to rotation about an axis 14 parallel to the axis II and which constitutes the main axis of the wheel device. If we define, by convention, the longitudinal direction 4 as being the forward direction of the vehicle 1, the two arm-shaped supports 8 located in front of the vehicle 1 form a cantilever towards the front with respect to the respective axis of articulation on the frame 10 while the arm-shaped supports 8 of the wheel devices 7 placed behind the vehicle 1 form a rear overhang with reference to the corresponding axis 11 respectively.

 At its first end 9, each arm-shaped support 8 has an integral part, for example by making it in a single piece of casting, an appendage 15 oriented radially with reference to the axis 11 respectively corresponding and on which is articulated, around an axis 16 parallel to axis 11, a longitudinal link 17 connecting with a slide 18, guided in longitudinal sliding relative to the framework 10, by means the production of which is within the capabilities of a man of loom, and resiliently biased, when sliding longitudinally with respect to the framework 10, also by means the production of which falls within the normal aptitudes of a person skilled in the art, so that by means of the connecting rod 17, approximately longitudinal in all the useful orientations of the arm-shaped support 8 around the axis 11 relative to the frame 10 and articulated on the slide 18 around an axis 92 parallel to the axis 16, they tend to pivot the corresponding support 8 respectively downwards around the respective axis 11, relative to the frame 10 of the vehicle 1; of course, this is only a non-limiting example of suspension of the vehicle 1, which could be equipped with a suspension of a different type or, if circumstances allow, be deprived of suspension; in the latter case, each support 8 in the form of an arm would be directly integral with the frame 10 of the vehicle 1, or would form an integral part of this frame.

 As best shown in Figures 3, 5, 7, the wheel 13 which equips the end 12 of each support 8 in the form of an arm is of a type, known in itself in general, comprising a hub 19 mounted at rotation about the main axis 14 on the end 12 of the support 8, in a position in which this hub has a mean plane 20 also constituting a mean plane for the support 8; in the direction of a distance with respect to the axis 14, the hub 19 is delimited by an outer peripheral face 21 cylindrical of revolution around the axis 14, pierced with an even number of mutually identical cells 22 disposed laterally relative to plane 20; more precisely, these cells 22 succeed one another circumferentially, with reference to the axis 14, being arranged alternately on either side of this mean plane 20, with a slight mutual overlap, in the circumferential direction around the axis 14, as shown in Figure 5. In each of the cells 22 is mounted on the hub 19, integral with the latter, a straight shaft 23 disposed along a respective secondary axis 24 located in one of two planes 25, 26 parallel to the mean plane 20, located respectively on either side of it and mutually symmetrical with respect to it, depending on whether one refers to a cell 22 located on one side or the other of this mean plane 20, respectively; the axes 24 corresponding to the cells 22 located on the same side of the plane 20 are located in the same plane 25 or 26, respectively, at a distance from the main axis 14 which is the same for all the axes 24; in addition, the axes 24 are angularly distributed around this axis 14, whether we refer to the axes 24 located on the same side of the mean plane 20 or to all of the axes 24, indifferently located on one side or on the other of this mean plane 20. This angular equal distribution for example refers to planes 65 each of which is perpendicular to a respective axis 24 and constitutes a plane of symmetry of the corresponding socket 22.

 Thus, a non-limiting example has been illustrated of a wheel 13 comprising six cells 22 having planes of symmetry 65 mutuellemet angularly offset by 300 for two cells 22 succeeding one another in circumferential direction but located respectively on either side of the plane medium 20, and 600 for two cells 22 succeeding each other in the circumferential direction being located on the same side of the medium plane 20 but it is possible to choose a number, and consequently a distribution, different without departing from the scope of this invention.

 Inside each cell 22, the hub 19 carries, at rotation about the respective axis 24, a respective roller 28 symmetrical with respect to the respective plane 65 and identical from one cell 22 to the other; each of these rollers 28 has an outer peripheral face 27 in the form of a spindle, of revolution around the corresponding axis 24 respectively, with a dimensioning such that, in any orientation of each roller 28 around the respective secondary axis 24 relative to at the hub 19, the outer peripheral face 27 thereof has, in the direction of a distance with respect to the axis 14, a respective generator 29 matching a geometric envelope 30 cylindrical of revolution around the axis 14, identical for all the rollers 28 and having a diameter greater than that of the external peripheral face 21 of the hub 19 so that this external peripheral face 21 is placed completely set back towards the axis 14 relative to the casing 30. Each roller 28 is immobilized in translation along the axis 24 inside the corresponding socket 22, by abutment in one and the other direction of the axis 24 against the hub 19, such that, like the cells 22 when the wheel 13 is seen along its axis 14, as shown in FIG. 5, the generatrices 29 of the outer peripheral faces 27 of the different rollers 28 follow one another in circumferential direction, along the envelope 30, with a slight mutual overlap with regard to two rollers 28 succeeding each other by being arranged respectively on either side of the mean plane 20.

 The diameter of the envelope 30 is also such that this envelope forms a projection towards the surface 2, with respect to the support 8, perpendicular to the main axis 14, in any orientation capable of being taken by the support 8 with respect to the frame 10 of the vehicle I under normal traffic conditions, so that at all times, the wheel 13 rests on the surface 2 by the generator 29, furthest from the axis 14, of a roller 28 whatever the orientation of the wheel 13 around the main axis 14 relative to the support 8.

 Advantageously, the adhesion of the wheel 13 on the surface 2, as well as a portion of damping in the rolling, are ensured by the fact that the outer peripheral face 27 of each roller 28 is elastically compressible; for this purpose, as shown in FIG. 5, each roller 28 can advantageously be formed of a rigid core 91, ensuring on the one hand the mounting on the shaft 23, for example by means of bearings 31, facilitating the rotation about the axis 24 relative to this shaft 23 and relative to the hub 19, and on the other hand a stop in one and the other direction of the axis 24 between the hub 19, for example by l intermediary of a respective lubricating ring 32, and of a peripheral coating 33 of an elastically compressible material, and for example having the elasticity of the rubber. This is however only a non-limiting example of the production of a roller 28 , and one could choose other embodiments without departing from the scope of the present invention.

 To ensure its mounting, and with it the mounting of the wheel 13, to rotation about the axis 14 on the end 12 of the corresponding support 8, each hub 19 has, projecting along the axis 14 respectively from share and on the other side of the mean plane 20, in the direction of a distance from the latter, two pins 34 and 35 each of which traverses right through, along the axis 14, a respective branch 36, 37 of the support 8 , in the form of a yoke at its end 12, and is guided in rotation around the axis 14 in this branch 36, 37 respectively by means of a bearing 38, 39. Between the branches 36 and 37 of the support 8, the hub 19 has around the respective corresponding tourbillon 34, 35 an annular shoulder 40, 41 plane, perpendicular to the axis 14 and pressing parallel to the latter against the branch 36, 37 respectively corresponding via a respective elastic washer 42, 43 in compression preload followed nt the axis 14 and further ensuring a seal, at least to dust, between the hub 19 and the branch 36, 37 respectively corresponding.

 One of the pins, for example the pin 34, forms a projection along the axis 14 with respect to the corresponding branch 36, in the sends of a distance from the hub 19, and bears integrally, at the level of this projection, a pinion 44 in permanent engagement, by means of a train of pinions 45 and of a device 46 for returning the angle to 90, both carried by the branch 36 and protected by a removable casing 48, with a motor shaft 47 guided in rotation on itself, around an axis 49, inside the support 8; this drive shaft 47 is in permanent engagement, inside of it, by means of a double sliding cardan joint 50, with another drive shaft 51 meanwhile guided in rotation about an axis 52 inside the frame 10 of the vehicle 1 and itself engaged, by means of a torque limiter 53, with a ring gear 54 also guided in rotation about an axis 55 to l 'interior of the frame 10 of the vehicle 1; this ring gear 54 is itself in permanent engagement, via a gear train 56, with a traction or propulsion motor 57 mounted on the frame 10 of the vehicle 1 and also driving the hub 19 of each of the other wheels 13 rotating around the respective main axis 14 via the crown 54 and a respective torque limiter 53 in permanent engagement with this crown 54, as shown diagrammatically in FIG. 4, it being understood that each torque limiter 53 is connected to the hub 19 respectively associated by transmission means identical to those which have been described with reference to one of these hubs 19. The motor 57 can operate at any energy, chosen according to the environment in which the vehicle 1 must move; it can in particular be electric, and be supplied either by accumulator batteries on board the vehicle 1, or by collecting means of known type if the vehicle 1 moves along a permanently determined trajectory, or by a flexible connecting umbilicus with a source of electricity fixed relative to the surface 2, in a known manner in particular in the field of handling and in that of the internal exploration of the fluid transport pipes.

 Naturally, instead of providing a traction or propulsion motor 57 common to all of the wheels 13 of the vehicle 1, one could provide several motors, suitably controlled, associated with respective wheels 13 or with respective groups of wheels 13, d '' a way easily conceivable by a skilled person.

 Preferably, means are provided for immobilizing the four wheels 13 in rotation about the main axis 14 relative to the corresponding support 8, in a controlled manner and for example automatically controlled when the traction motor is stopped. 57 thus, when the latter is an electric motor, it is advantageous to provide between this motor 57 and the pinion train 56 a brake 58 with lack of current, to automatically cause the immobilization of each wheel 13 around the main axis 14 when the motor 57 is no longer supplied with electricity; the torque limiters 53, the main function of which is to allow a slight difference in the speed of rotation of the different wheels 13 around the main axes 14 relative to the supports 8, however, allow the vehicle 1 to then roll voluntarily in a direction involving a rotation of the wheels 13 around the respective main axis 14, by applying to it a push or a traction exceeding a determined threshold, that the simple driving of the vehicle 1 by its own weight and that of the load which it possibly carries is insufficient to overcome.

 Naturally, the means for driving the hub 19 of each wheel 13 to rotate about the main axis 14 relative to the corresponding support 8 can also have many variants without departing from the scope of the present invention. , in particular depending on how the supports 8 are mounted on the frame 10 and the environment in which the vehicle 1 must operate; in particular, in the case of a vehicle intended to evolve out of any possibility of visual control, for example when exploring a pipeline as will be described with reference to FIGS. 8 to 13, provision is advantageously made in association with one of the wheels 13, for example at the level of the angle transmission device 46 as illustrated in FIGS. 3 and 4, an incremental encoder 59 making it possible to measure the displacement of the vehicle 1 along its determined trajectory through the pipeline.

 Naturally, the immobilization of the hub 19 of each wheel 13 in rotation about the main axis 14 relative to the corresponding support 8 does not ensure complete immobilization of the vehicle I insofar as each roller 28 can nevertheless rotate around the corresponding axis 24, respectively, relative to the hub 19, and thus authorize a rolling of the vehicle 1 on the area 2 perpendicular to its mean longitudinal axis 6.

 To prevent such a bearing at will, as well as to ensure, if necessary, a rotation of each hub 19 around the main axis 14 relative to the corresponding support 8 without the possibility of rotation of the rollers 28 around the axes 24 relative to the hub 19, which results in a rolling of the vehicle 1 along a rectilinear trajectory parallel to its mean longitudinal axis 6, means are provided in accordance with the present invention at will for each roller 28 at rotation around the axis 24 corresponding to hub 19.

 These means are more particularly visible in Figures 6 and 7, with reference to which they will now be described.

 It emerges from the examination of these figures, as well as that of FIGS. 3 and 5, that the hub 19 is pierced right through, along the axis 14, with a passage 60 delimited by an inner peripheral face 61 cylindrical of revolution around the axis 14 except at the pin 35, inside which the passage 60 is delimited by an inner peripheral face 62 frustoconical of revolution around the axis 14 and widening from the face inner ring road 61.

 Opposite each roller 28, in a respective direction 63 at least approximately radial with respect to the main axis 14 as with respect to the respective secondary axis 24, the passage 60 has between the axis 14 and this roller 28 a branching 64, in practice delimited by an inner peripheral face 66 cylindrical of revolution about an axis perpendicular to the main axis 14 as to the respective secondary axis 24 and to which the reference 63 has also been assigned; this axis 63 is defined by the intersection of the respective plane 65 with the plane 25 or with the plane 26 depending on whether the roller 28 considered is located on one side or the other of the mean plane 20. Each branch 64 thus opens out by its face 66 towards the respective roller 28 and, towards the main axis 14, it has a localized narrowing forming an annular shoulder 67, of revolution around the respective axis 63 and turned in the direction of a distance from the axis 14.

 Each ramification 64 ensures, by its inner peripheral face 66, the sliding guide in the respective direction 63 relative to the hub 19, of a respective piston 68 having towards the main axis 14 a tail 69 forming a projection towards this axis 14, relative to the inner peripheral face 61 of the passage 60, when the piston 68 is in abutment towards the axis 14 against the respective corresponding shoulder 67 in this position, the piston 68 respects the external peripheral face 27 of the roller 28 corresponding to a clearance 70 allowing the free rotation of this roller 28 around the respective secondary axis 24 relative to the hub 19. An O-ring 71, having a specific elasticity allowing it to roll on itself when the piston 68 moves in the direction of a distance relative to the main axis 14 inside the corresponding branch 64 until it comes into contact with the outer peripheral face 27 of the g alet 28, by applying sufficient pressure to the latter, towards the respective axis 24, to immobilize the roller 28 against rotation about this axis relative to the hub 19, then allows to accumulate elastic energy which tends to automatically return the piston 68 to its position in abutment against the shoulder 67 towards the main axis 14.To this end, this O-ring 71, of revolution around the axis 63, is housed at the inside of a groove 72 of the piston 68, itself annular of revolution around the axis 63, and it is placed in radial compression preload, with reference to this axis, between this groove 72 and the peripheral face 66 of the branch 64; it also provides a seal between the corresponding piston 68 and the hub 19. The piston 68 is dimensioned so that its tail 69 is flush with the inner peripheral face 61 of the passage 60 when it is applied against the outer peripheral face 27 of the corresponding roller 28, towards the respective secondary axis 24, under conditions suitable for preventing rotation of this roller 28 around this secondary axis 24, with respect to the hub 19, as indicated above.

 To make the different pistons 68 evolve in a controlled manner, simultaneously, between their position in which they observe a clearance 70 vis-à-vis the outer peripheral face 27 of the corresponding roller 28 respectively and their position in which they immobilize this roller 28 to against a rotation around the corresponding secondary axis 24 relative to the means 19, inside the passage 60 is mounted, to sliding along the axis 14 relative to the hub 19, a slide 73 capable of move between two limit positions, one of which has been illustrated in FIG. 7 and corresponds to the preservation of the clearance 70. With a view to guiding it sliding along the main axis 14 inside the passage 60, the drawer 73 has an outer peripheral face 74 cylindrical of revolution around the main axis 14 with a diameter substantially identical to that of the inner peripheral face 61, so as to ensure not only the guida aforementioned ge, relative translation along the axis 14, but also a possibility of relative rotation about the axis 14, the slide 73 being fixed against a rotation around the axis 14, relative to the support 8, in the nonlimiting example illustrated.

 However, to allow the projection of each tail 69 towards the main axis 14, relative to the inner peripheral face 61 of the passage 60, corresponding to the preservation of the games 70, the outer peripheral face 74 of the drawer 73 is hollowed out, at least in two mutually spaced locations along the axis 14 by a distance corresponding to the distance separating along this axis the planes 25 and 26, of a respective annular groove 75, 76, annular of revolution around the axis 14. In the position of the slide 73 illustrated in FIG. 7, the grooves 75 and 76 are arranged respectively along the plane 25 and along the plane 26, which allows each piston 68 to occupy its position in abutment against the corresponding shoulder 67 respectively, towards the main axis 14.

 In a determined direction 77 of the axis 14, each of these grooves 65, 76 has a gently sloping side in the direction of a distance from the main axis 14, up to the cylindrical outer peripheral face 74 of revolution around this axis 14. Therefore, by moving the slide 73 in translation along the axis 14, inside the passage 60, in direction 78 opposite to direction 77, it is possible to bring opposite each tail 69 the cylindrical outer peripheral face 74 of the slide 73, and thus cause each piston 68 to come into abutment against the outer peripheral face 27 of the roller 28 respectively associated, towards the respective secondary axis 24, and thus immobilize each roller 28 to rotation around the respective secondary axis 24 relative to the hub 19.

 To cause such a translation of the drawer 73 in a controlled manner, it has inside the pin 35 a yoke 79 by which it is articulated, around an axis 80 perpendicular to the main axis 14 and to a plane , not referenced, including this axis 14 and the axis 49 of the motor shaft 47, on a connecting rod 81 which is also articulated around an axis 82 parallel to the axis 81, on a lever 83 mounted for pivoting on the branch 37 of the support 8, around an axis 84 parallel to the axes 81 and 82; the lever 83 is also articulated around an axis 85 parallel to the axes 84, 82 and 81, on the rod 86 of an electric actuator 87 whose body 88 is pivotally mounted, around a parallel axis-89 axes 85, 84, 82 and 80, on the support 8. A housing 90 removably mounted on the branch 37 of the support 8 in a position symmetrical to that of the housing 48 relative to the plane 20 covers the yoke 79, the link 81, the lever 83 and the jack 87.

 The cylinders 87, associated with the different wheels 13, as well as the traction or propulsion motor 57 are remotely controlled, by appropriate means the production of which is apparent from the normal aptitudes of a person skilled in the art, as a function of movements and stops. that you want to impose on the vehicle 1.

 Naturally, this embodiment of the immobilization means controlled by each roller 28 in rotation about the respective secondary axis 24 relative to the hub 19 of a wheel 13 is only a non-limiting example, with respect to which may provide many variations without departing from the scope of the present invention.

 In general, the wheel device according to the invention as well as the vehicle according to the invention may have many variations compared to the arrangements which have just been described, in particular depending on the destination of this device and of this vehicle. .

 By way of illustration of these possibilities of a variant of vehicles fitted with wheel devices according to the invention, there is illustrated in FIGS. 8 to 13 a vehicle 101 intended to travel internally through a pipe 102, supported by wheel devices 7 according to the invention, here 6 in number, on an inner peripheral face 103 thereof by crossing not only straight sections of this pipe 102, but also any bend thereof. If we consider a straight section of the pipe 102, the face 103 has a cylindrical shape of revolution around a rectilinear axis 104 defining a longitudinal direction 105, where appropriate with variations in diameter and centripetal radial projections such as thimbles 106 or gaps such as nozzles 107; in the curves of the pipe 102, the face 103 of the latter retains a circular current section, if necessary also with projections or gaps.

 As it progresses longitudinally in the pipe 102, in a motorized manner, in one or the other of the two mutually opposite directions 108, 109, respectively front and rear by convention, of the direction 105, the vehicle 101 can turn on itself, around the axis 104, to allow the wheel devices 7 to avoid obstacles such as the thermowells 106 or the taps 107, by means of arrangements which will now be described.

 If one refers to the longitudinal direction 105 and the directions 108 and 109, respectively front and rear, thereof, the vehicle 101 comprises a frame 110 formed from the longitudinal juxtaposition of a front module 111 and a rear module 112, carriers in that they are both provided with wheel devices 7 according to the invention. The longitudinal direction 105 will subsequently be considered to be linked to this framework 110.

 The module 111 is for example provided, in an extreme front zone, with exploration means 113 such as cameras associated with projectors while the rear module 112 is for example provided, in a rear extreme zone, with a flexible umbilicus 14 connecting the vehicle 110 to means 121 of command and control located outside the pipeline, through the orifice used to introduce the vehicle 101, on the one hand to be used for supplying energy, in particular electrical energy, of the various components of the vehicle, in particular exploration means 113 and of a certain number of generally electric motors which will be described later, and on the other hand for the transmission of information either to the vehicle 101 , from the command and control means t 21, for controlling the operation of the vehicle and its various components, ie from the vehicle 101 to the command and control means 1 21 to allow the control of the operation of the components of this vehicle and to convey the information coming from the exploration means 113.

 Naturally, the exploration means 113 could be replaced or supplemented by any other type of equipment of the vehicle 101, for example by tools, in particular remote-controlled from the means 121.

 The two modules 111 and 112, both rigid, are connected to each other by a longitudinally central module 115, also rigid, by means of means allowing relative rotation around the same longitudinal axis 116 specific to the frame 110 of vehicle 101, to the exclusion of any other possibility of relative movement. For this purpose, for example, the central module 115 has a longitudinal projection 117, 118 inside each of the carrier modules 111, 112, and a respective ball ring 119, 120, of axis 116, is interposed between this 117, 118 and the corresponding carrier module 111, 112.

 Naturally, other means of mutual articulation of the carrier modules 111, 112 to the relative rotation around the axis 116 without any other possibility of relative displacement could be provided; in particular, one could provide a direct connection, that is to say without the intermediary of the central module 115, of the two carrier modules 111 and 112; a person skilled in the art will bring to the arrangements which have just been described, as well as to the arrangements which will be described with regard to the control of the carrier modules 111, 112 at the relative rotation around the axis 116, without however leaving the part of the present invention.

 In the example illustrated, this relative rotation of the two carrier modules 111, 112 around the axis 116, or torsion of the frame 110, can be effected by controlled rotation of each of them, around the axis 116, with respect to the central module 115, as desired, in a commanded and controlled manner from command and control means 121 external to the pipe 102.

 To this end, as shown in FIG. 10, between each of the ball crowns 119, 120 and the axis 116, the central module 115 integrally carries a respective toothed crown 171, 172, also of axis 116.

 With the crown 171 is permanently engaged a pinion 122, of axis 124 parallel to the axis 116, constituting the movement output of a motor 124 for torsion of the frame 110, carried integrally by the front carrier module 111; this motor 124, preferably electric, can be supplied in a controlled manner, from the monitoring and control means 121, to induce a rotation of the module 111 at will in one direction or the other around the axis 116 by relative to the central module 115, or stopping the module 111 in a determined orientation, around the axis 116, relative to the module 115; this orientation can be known at all times, at the command and control means 121, to which an encoder 125, constituted by a rotary potentiometer, also mounted integrally by the front module 111 and comprising a pinion, not shown, in permanent engagement with the toothed crown 171, transmits information in this regard.

 Similarly, with the ring gear 172 is in permanent engagement a pinion 126, of axis 127 parallel to the axis 116, constituting the movement output of a motor 128 for torsion of the frame 110; this motor 128, preferably electric, is carried integrally by the rear module 112 and controlled, from command and control means 121, so as to induce a rotation of the module 112 in one direction or in the other, around the axis 116, relative to the module 115 or stop the module 112 in a determined orientation, chosen at will, around the axis 116 relative to the module 115; an encoder 129, constituted by a rotary potentiometer, carried integrally by the rear module 112 and carrying a pinion not referenced in permanent engagement with the ring gear 172 transmits to the command and control means 121 information making it possible to know at all times this orientation.

 Preferably, not illustrated but easily conceivable by a person skilled in the art, free stops, associated with microswitches controlling the stopping of the torsion motor 124 or of the torsion motor 128, as the case may be, are provided to limit rotation modules 111 and 112 relative to module 115, for example 1200 in the example illustrated in which each carrier module 111, 112 carries three wheel devices 7 according to the invention, identical and regularly distributed angularly around the axis 116 , this number and this distribution can however be different and the person skilled in the art then appropriately choosing the limit amplitude of the respective rotations of the two carrier modules 111 and 112 relative to the central module 115.

 Likewise, in a manner easily conceivable by a person skilled in the art, provision is preferably made, at the command and control means 121, for arrangements such as the torsion motors 124 and 128 can only be supplied with electrical energy alternately. , so that the two carrier modules 111 and 112 cannot rotate at the same time with respect to the central module 115.

 It will be noted that the same angular offset, determined, between the two carrier modules 111 and 112, around the axis 116, can be obtained either by actuation of the torsion motor 124 or actuation of the torsion motor 128, which increases the vehicle reliability 101.

 A controlled torsion of the frame 110, around the axis 116, by means of the torsion motors 124 and 128, allows the wheel devices 7 according to the invention with which both of the carrier modules 111 are fitted. and 112 to avoid obstacles to the progression of the vehicle 101, which may constitute the projections and the gaps of the inner peripheral face 103 of the pipe 102, for example in the form of glove fingers 106 or nozzles 107 respectively.

 Each of the wheel devices 7 is identical to the wheel device 7 described with reference to FIGS. 1 to 7, so that FIGS. 8 to 12 show the same references to designate the same components.

 As mentioned above, each carrier module 111, 112 carries three of these wheel devices 7, which are mutually identical and each consists of a support 8 in the form of an arm, articulated on the corresponding carrier module around a respective axis. articulation 11 and carrying a respective wheel 13; on each carrier module 111, 112, the wheel devices 7 are regularly distributed angularly around the axis 116, generally coincident with the axis 104 in the straight sections of the pipe 102. In other words, the mean plane 20 of each wheel device 7 passes through the axis 116 and the mean planes 20 of the wheel devices 7 of the same carrier module are mutually angularly offset, around this axis 116, by 1200 although other arrangements, in particular associated with a greater number of wheel devices 7 on each carrier module 111, 112, can also be adopted without departing from the scope of the present invention.

 Reference will be made to the description of FIGS. 1 to 7 with regard to the production of each wheel device 7.

 Preferably, as illustrated, the axes 11 of articulation of the wheel devices 7 corresponding to the same carrier module 111, 112 on the frame 110, that is to say the axes of articulation respectively on this module carrier 111 or on this carrier module 112, are arranged in the same plane 130, 131 perpendicular to the axis 116, the two planes 130 and 131 being mutually symmetrical with respect to a plane 132 itself perpendicular to the axis 116 and constituting a plane of symmetry at least approximate for the module 115 and a plane of mutual symmetry at least approximate for the bearing modules 111 and 112. The different axes 11, that is to say the planes 130 and 131, are also as close as possible to this plane 132 so that the modules 111 and 112 have most of their longitudinal dimension respectively in front of the plane 130 and behind the plane 131, in the form of a tubular sheath, respective longitudinal 133, 134 from p lus small transverse dimension and larger longitudinal dimension than the module 115 and that the areas of the carrier modules 111 and 112 directly adjacent thereto; preferably, as illustrated, at each of the tubular sleeves 133, 134 as at these areas directly adjacent to the module 115, the modules 111 and 112 are delimited in the direction of a distance from the axis longitudinal 116 by an external peripheral face 135, 136, 137, 138, respectively, cylindrical of revolution about the axis 116; the faces 135 and 137, respectively of smaller diameter and larger diameter, of the carrier module 111 are connected to each other by an annular, flat, transverse shoulder 142, as are the faces 136 and 138, respectively of smaller diameter and larger diameter, of the module 112 are connected to each other by an annular shoulder 143, plane, perpendicular to the axis 116, these shoulders 137 and 138 being turned respectively towards the front and towards the rear; the module 115 is advantageously delimited in the direction of a distance relative to the axis 116 by an outer peripheral face 139 cylindrical of revolution around this axis 116 with a diameter substantially identical to that of the outer peripheral faces 137 and 138 respectively of the carrier module 111 and the carrier module 112.

 Respectively on the carrier module 111 and on the carrier module 112, the axes 11 of articulation of the wheel devices 7 are defined by respective yokes 140 projecting forward on the shoulder 142, inside a cylindrical geometric envelope defined by a longitudinal extension of the outer peripheral face 137, around the sheath 133, and by yokes 141 projecting rearwards on the shoulder 143, inside a cylindrical envelope merged with the previous one and defined in turn by a longitudinal extension ta outer peripheral face 138, around the sleeve 134. Each yoke 141, 143 is secured to the carrier module 111, 112 correspondingly respectlxement.

 In order to guide the corresponding slides 18 along the longitudinal slide, the outer peripheral face 135, 136, of smaller diameter, of each sleeve 133, 134 has, along each of the mean planes 20, a respective slide 144, 145, by example in the form of a respective longitudinal rib.

 In addition, inside each slide 118 longitudinally penetrates a respective longitudinal piston 146, 147 immobilized transversely with respect to the corresponding corresponding carrier module 111, 112 but adjustable longitudinally with respect to this corresponding carrier module 111, 112, by means which will now be described with reference to FIG. 11, with regard to the wheel devices 7 of the front carrier module 111, it being understood that an identical assembly is provided for each of the wheel devices 7 of the rear carrier module 112.

 It appears from FIG. 11 that each piston 146 has a rear end section 148 received and guided in the longitudinal sliding in a housing 149 arranged in the yoke 140 of the corresponding wheel device 7, and a front end section 150 received and guided in the longitudinal sliding in a longitudinal blind hole 151 of the corresponding slide 18; similarly, not shown, each piston 147 has a front end zone received in a housing at all points similar to the housing 149 but arranged in the yoke 141 respectively corresponding, and a rear end zone housed in a blind hole fitted in the corresponding slide 18 and at all points similar to the blind hole 151, in both cases with guidance to the relative longitudinal sliding.

 Inside each blind hole 151 is disposed a spring 152 for example formed by a longitudinal stack of elastic washers, working in longitudinal compression between the front end section 150 of the piston 146 and the transverse bottom 153 of the blind hole 151 and a Those skilled in the art will readily understand that this spring 152 ensures the elastic suspension of the corresponding wheel device 7; naturally, a similar spring, working under compression, is interposed between the rear end zone of each piston 147 and the bottom of the blind hole provided in the corresponding slide 18 to receive this rear end zone.

Indeed, on the front carrier module 111, the arm-shaped supports 8 of the wheel devices 7, and in particular their axes 11 of articulation on this carrier module 111, are arranged so that
each link 117 is oriented approximately longitudinally, towards the rear, from its articulation around the axis 92 on the slide 18 to its articulation around the axis 16 on the support in the form of an arm 8,
the articulation axis 11 is located further from the axis 116 than this axis 16, and
- from this articulation axis 11 towards the corresponding main axis 14, the arm-shaped support 8 is oriented towards the front, diverging with respect to the axis 116, in all the deployment orientations of this support in the form of an arm 8 around the axis 11, relative to the carrier module 111, these directions of deployment of the wheel devices 7 corresponding to a bearing on the peripheral face 103 of a pipe 102 as shown in FIGS. 9 and 11 as well as, in its right part, FIG. 8, while each arm-shaped support 8 is oriented substantially longitudinally, towards the front, from its articulation axis 11 to the corresponding main axis 14 in a limit folding position, illustrated in the left-hand half of FIG. 8, corresponding to a storage and handling position in particular through a pipe orifice 102 to introduce the vehicle 101 therein or to extract it therefrom.

On the rear carrier module 112, the arm-shaped supports 8 are arranged, in particular as regards their axis 11 of articulation on this rear carrier module 112, so that
each link 17 is oriented approximately longitudinally rearward, from its axis 92 of articulation on the corresponding slide 18 towards its axis 16 of articulation on the support in the form of a corresponding arm 8,
the axis 11 of articulation on the carrier module 112 is offset in the direction of a distance from the axis 116 with respect to this axis 16 and
- From this articulation axis 11 to the corresponding main axis 14, each arm-shaped support 8 is rotated rearward, gradually moving away from the axis 116 if it occupies a deployment position corresponding to the rolling on the inner peripheral face 103 of a pipe 102, or being oriented approximately longitudinally in a limit folding position.

 In order to impose a limit on the crushing of each spring 152, that is to say a limit on the deflections of the elastic suspension in the direction of approximation of the corresponding wheel 13 vis-à-vis the axis 116, each piston 146 has between the slide 18 and the yoke 140 a transverse flange 154 which serves as a stop, rearward, the slide 18 for a determined longitudinal position of the piston 146; likewise, each piston 147 has an annular, transverse flange 155 between the slide 18 and the yoke 141, to constitute a rearward stop, for the slide 18, for a determined longitudinal position of the piston 147.

 The longitudinal position of each flange 154, 155, i.e. the limit of travel of the corresponding suspension in the direction of the compression of the spring such as 152, can be adjusted by adjusting the longitudinal position of the pistons 146 to in unison, with respect to the yokes 140, on the one hand, and pistons 147 in unison, with respect to the yokes 140, on the other hand, mutually independently.

 The means used for this purpose will be described with reference to FIGS. 11 to 13, with regard to the pistons 146 and the front carrier module 111, it being understood that the rear carrier module 112 and the corresponding pistons 147 are equipped with similar means, so easily transposable, by a skilled person, from the indications which will be given now.

 It appears from the examination of FIG. 11 that each housing 149, like the corresponding piston 146, has a longitudinal axis 156 around which the piston 146 is prevented from turning inside the housing 149, for example by engagement of a transverse pin 157 of the rear section 148 of the piston 146 in a longitudinal groove 158 of the housing 149.

 In addition, each piston 146 has, along the axis 156, an internal thread not referenced, engaged with an external thread, also not referenced, of a screw 159 with axis 156.

 This screw 159 is guided in rotation about the axis 156 with respect to the corresponding yoke 140, without any other possibility of relative movement, for example by means of thrust bearings 160 closing the housing 149 towards the rear.

 Behind these bearings 160, the screw 159 extends, inside the front module 111, in the form of an extreme cantilevered zone in which it carries, in an integral manner, a coaxial pinion 161.

 As shown more particularly in FIG. 12, the pinions 161, three in number, corresponding to the three wheel devices 7 of the front carrier module 111 are mutually identical and in permanent engagement with a transverse toothed crown 142, of axis 116, guided to rotation about this axis 116 inside the front carrier module 111 by any appropriate means, not shown, the production of which falls within the normal abilities of a person skilled in the art.

 This ring 162 is also in permanent engagement, by means of a pinion 163 mounted for rotation about a longitudinal axis 164 inside the front carrier module 111, with a pinion 165 also mounted for rotation around d a longitudinal axis 166 inside this front carrier module 111 and constituting the movement output of a geared motor 167, advantageously electric, carries integrally by the front carrier module 111 and controlled by the control means and control 121; the rear carrier module 112 has its own motor, not illustrated, independent of the motor 167, for controlling the respective longitudinal positions of the piston 147.

 It is easily understood that by retracting each piston 146, 147 in its housing of the respective corresponding yoke 140, 141, one causes or authorizes a folding of the corresponding wheel 13 towards the axis 116 and that by leaving each piston 146, 147 from its housing in the corresponding yoke 140, 141 respectively, there is a tendency to separate the corresponding wheel 13 from the axis 116.

 To allow, at the command and control means 121, to know at all times on the one hand the adjustment of the longitudinal position of each piston 146 or 147 vis-à-vis the respective clevis 140, 141, c that is to say the orientation that each support in the form of an arm 8 can reach by way of limit of movement towards the axis 116, by abutment of the corresponding slide 18 on the flange 154 or 155 of the associated piston 146 or 147, as well as the effective orientation of each arm-shaped support 8 around the corresponding axis 11 with respect to the yoke 140 or 141, each piston 146, 147 and each slide 18 is connected to a respective sensor such as a potentiometer linear 168, 169, as shown in FIG. 13 with regard to a piston 146, it being understood that a symmetrical mounting of the latter relative to the plane 132, assuming that the two carrier modules 111, 112 are oriented in such a way so that the 20 planes coincide with one to the other, being adopted at the level of a piston 147.

 It will be noted that a single piston 146 and a single piston 147 and the corresponding sliders 18 can thus be equipped with sensors of their respective longitudinal position.

 However, it is preferred to equip each piston 146, 147 and the corresponding slides 18, the differential longitudinal travel of the two potentiometers associated with the piston and the slide corresponding to the same wheel 13 making it possible to measure the average preload on this wheel.

 Naturally, these devices can be associated with safety devices, not shown, capable of transmitting information to the command and control means 121 or, possibly, of triggering automatic mechanisms, such as microswitches detecting the coming of the sliders 18 in abutment. against the flanges 154, 155 of the pistons 146, 147, which corresponds to the maximum preload of the corresponding wheel 13 respectively, and of the microswitches detecting the arrival of each support in the form of an arm 8 in a limit orientation, ie of folding back, or deployment (respectively left part and right part of Figure 8).

 If necessary, means can be provided to avoid accidental misalignment of the longitudinal position of the pistons 146 and 147, for example in the form of an undercurrent brake 170 associated with each of the two geared motors such as 167 provided for this adjustment.

 In addition, during the evolution of the vehicle 101 in the pipe 102, the geared motors such as 167 provided for the longitudinal adjustment of the pistons 146 and 147 are preferably controlled by the motors 124 and 128 for torsion of the frame 110 and the means of longitudinal propulsion of the vehicle 101 which will now be described, in order to permanently maintain a suitable pressure for applying each wheel 113, in the direction of a distance from the axis 116, on the inner peripheral face 103 of the pipe 102, in particular when crossing curves.

 To ensure the longitudinal propulsion of the vehicle 101 inside the pipe 102, each of the carrier modules 111, 112 has its own means, similar to those which have been described with reference to FIG. 4 to which reference will advantageously be made to this respect.

 In other words, each of the carrier modules 111, 112 has its own propulsion motor 57, advantageously electric, controlled and controlled by the command and control means 121 and associated with its own brake 58 with lack of current, with its own gear train 56 in permanent engagement with a ring gear 54 mounted for rotation about the axis 116, without any other possibility of relative movement, inside the carrier module 111, 112 respectively corresponding and in engagement, by the intermediate of three torque limiters 53 with respective longitudinal axes, also housed inside the corresponding carrier module 111, 112, with three shafts 51 mounted for rotation about longitudinal axes inside this carrier module and ensuring a transmission of movement to the wheel 13 of a respective wheel device 7 of this carrier module 111 or 112, inside the support in the form of a corresponding arm 8, via the components 50, 49, 47, 46, 45, 44 described with reference to Figure 4; an incremental encoder 59 making it possible to measure the displacement of the vehicle 101 along its path inside the pipe 102 is advantageously associated with one of the wheels 13 of one of the carrier modules, for example of the rear carrier module 112 , according to the assembly described with reference to FIG. 4.

 Each wheel 13 is further associated with respective means of controlled immobilization or controlled release of each of its rollers 28, with respect to a rotation about the respective secondary axis 24 relative to the corresponding hub 19; these means are identical to those which have been described with reference to FIGS. 1 to 7, in particular to FIG. 7 in the description of which reference will be made to their subject; they are preferably controlled in unison with regard to the wheels 13 of the same carrier module 111, 112 but they are controlled mutually independently with regard to the wheels 13 of the carrier module 111 and those of the carrier module 112 , from the command and control means 121.

 Under normal operating conditions, the propulsion motors 57 associated respectively with one and the other of the carrier modules 111 and 112 are controlled in synchronism, so as to ensure the same rotation speed of the different wheels 13 around the main axes. 14, but these propulsion motors 57 can also be controlled independently of one another, as well as the motors such as 167 ensuring the deployment or the folding of the supports in the form of arms 8, in particular to facilitate the release of the vehicle 101 if one of the wheels 113 engages an obstacle inside the pipe 102, and for example engages in a tapping 107.

 However, the design of the vehicle 101 which has just been described makes it possible to avoid, as far as possible, this kind of accident, just as the abutment against a projection such as a glove finger 116 can be avoided thanks to the design of the vehicle 101 which has just been described.

 In fact, thanks to this design, it is easy to rotate this module on itself inside the pipe 102, around the axes 104 and 116 generally at least approximately merged at least in rectilinear travel, to angularly offset each wheel 13, around these axes, relative to a possible obstacle.

 This operation is preferably carried out while the longitudinal progression of the vehicle 101 in the pipeline 102 is stopped, in particular for reasons of ease of control, but could also accompany the progression of the vehicle 101 inside the pipeline 102.

 If it is assumed for example that while the vehicle 101 progresses longitudinally in the pipeline, under the action of propulsion engines such as 57 with coincidence of the mean planes of the wheel devices 7 of one of the carrier modules 111 with the mean planes 20 of the wheel devices 7 of the other carrier module 112, one of the wheels 13 of that of these carrier modules 111, 112 which is turned forward with reference to the direction of progression, it being understood that the vehicle 101 can move in either of the longitudinal directions 108 and 109 inside the pipe 102, is about to encounter an obstacle such as a thermowell 106 or a stitching 107, what can be detected, for example, by the cameras on board the vehicle 101, the propulsion of the latter is stopped by interrupting the supply of electricity to the propulsion engines such as 57, which immobilizes each wheel 13 in rotation about the axis principal 14 corr spying due to the presence of the brake such as 58 in the absence of current; the rollers 28 of the wheels 13 of one of the carrier modules 111, 112 are then freely immobilized, relative to the corresponding hub 19, by appropriate control of the respective immobilization means described with reference to FIG. 7, which prevents these rollers 28 to roll circumferentially, with reference to the axis 104, on the inner peripheral face 103 of the pipe 102 and therefore prevents the corresponding carrier module from rotating on itself therein, around the axes 104 and 116 at least approximately confused; on the other hand, the rollers 28 of the wheels 13 of the other carrier module 111, 112 are left free to rotate about their axis 24 relative to the corresponding hub 19, and this other carrier module can therefore rotate on itself, around axes 104 and 116, by rolling these rollers 28 on the inner peripheral face 103, in the circumferential direction.

 Then, by appropriately supplying the torsion motor 124 or 128 of one of the carrier modules 111, 112, also freely chosen, while one of them is thus immobilized against a rotation around axes 104 and 107 approximately coincident, inside the pipe 102, and while the other can accomplish such a rotation, the frame 110 is twisted around the axis 116, which causes an offset angular of the latter carrier module inside the pipe 102, in particular with regard to its wheels 113 which, thus, offset angularly relative to the obstacle to be avoided.

 Next, the rollers 28 of the wheels 13 which are thus angularly displaced inside the pipe 102 are immobilized with respect to the corresponding hub 19 and the rollers 28 initially immobilized are released, then by means of one of the torsion motors 124, 128, freely chosen, a new torsion of the frame 110 is caused until the wheels whose rollers 28 are thus released are placed in the longitudinal alignment of the wheels previously angularly offset, that is to say say also shift angularly with respect to a longitudinal extension of the obstacle to be avoided.

 All the rollers 28 can then be released with respect to a rotation relative to the corresponding hub 19, or possibly be immobilized against such a rotation, and the longitudinal progression of the vehicle 101 can resume, under the propulsion engines such as 57 suitably powered for this purpose.

 Naturally, like the vehicle 1, the vehicle 101 which laughs to be described is susceptible of numerous variants without departing from the scope of the present invention.

Claims (22)

 1. Wheel device, of the type comprising a wheel support (8), a wheel (13) itself comprising a hub (19) rotatably mounted on the support (8) about a main axis (14) determined, the hub (19) being inscribed in a geometric casing (30) cylindrical of revolution around the main axis (14), and a plurality of rollers (28) mounted free to rotate on the hub (19) around '' a respective secondary axis (24) determined, located in a plane (25, 26) perpendicular to the main axis (14), the rollers (28) having a respective periphery (27) of revolution around the respective secondary axis (24), which periphery (27) matches said envelope (30), and being distributed around the main axis (14) so that their peripheries (27) succeed one another on the envelope (30), in the direction circumferential, and motor means (44 to 47, 49 to 58) for controlled drive of the hub (19) to rotation about the axis main (14) relative to the support (8)  characterized in that it comprises means (60 to 89) for controlled immobilization of each roller (28) against a rotation about the respective secondary axis (24) relative to the hub (19).  2. Device according to claim 1, characterized in that it comprises means (58) of controlled immobilization of the hub (19) against a rotation about the main axis (14) relative to the support (8).  3. Device according to any one of claims 1 and 2, characterized in that the secondary axes (24) of the rollers (28) whose peripheries (27) succeed each other on the envelope (30) are located respectively by hand and on the other side of a mean plane (20) perpendicular to the main axis (14).  4. Device according to any one of claims 1 to 3, characterized in that the hub (19) has a passage (60) disposed along the main axis (14) and having a branch (64) opposite each roller (28), in a respective direction (63) at least approximately radial with respect to the main axis (14) and with respect to the respective secondary axis (24), and in that the means (60 to 89) d fixed assets include  - inside each branch (64) of the passage (66), a respective brake piston (68) guided in translation in the respective direction (63) relative to the hub (19) and having a tail (69) projecting towards the main axis (14), inside the passage (60),  - inside the passage (60), a slide (73) guided in translation controlled along the main axis (14) relative to the hub (19) and having a periphery (74 to 76) cooperating with the tails ( 69) of the pistons (68) so that, when the slide (73) occupies a determined position along the main axis (14) relative to the hub (19), each piston (68) is applied firmly against the periphery (27) of the respective roller (28) and immobilizes the latter relative to the hub and that, when the slide (73) occupies another determined position along the main axis (14) relative to the hub (19), each piston (68) is released towards the main axis (14) relative to the periphery (27) of the respective roller (28).  5. Device according to claim 4, characterized in that it comprises means (71) for elastic return of each piston (68) towards the main axis (14).  6. Device according to any one of claims 4 and 5, characterized in that the slide (73) is fixed in rotation about the main axis (14) relative to the support (8) and in that its periphery ( 74 to 76) has a shape of revolution around the main axis (14).  7. Device according to any one of claims 1 to 6, characterized in that the periphery (27) of each roller (28) has a sliding coefficient favorable to its adhesion to a rolling area (2).  8. Device according to any one of claims 1 to 7, characterized in that the periphery (27) of each roller (28) is elastically compressible.  9. Self-propelled vehicle, comprising a frame (10, 110) and wheel devices (7) connected to each other via this frame (10, 110) and intended to ensure the support of the vehicle (1, 101) on a rolling area (2, 103),  characterized in that at least one of the wheel devices (7) is a device according to any one of claims 1 to 8, the support (8) of which is carried by the framework (10, 110) and the the main axis (14) has a fixed direction relative thereto.  10. Self-propelled vehicle according to claim 9, characterized in that the support (8) is constituted by a member (8) for suspending the frame (10).  11. Self-propelled vehicle according to claim 10, characterized in that the motor means (44 to 47, 49 to 58) comprise a controlled propulsion motor (57) housed in the frame (10) and means (44 to 47, 49 to 56, 58) of kinematic connection between the propulsion motor (57) and the hub (19), housed at least partially in the suspension member (8).  12. Self-propelled vehicle according to any one of claims 10 and 11, characterized in that the support (8) consists of an arm (8) articulated on the frame (10, 110) around an axis of articulation (11) parallel to the main axis (14) and in that there are provided means (152) for resilient biasing of the arm (8) on pivoting, about the articulation axis (11) relative to the frame (10, 110), in a direction corresponding to a distance from the main axis (14) relative to the frame (10, 110).  13. Self-propelled vehicle according to claim 12, characterized in that it comprises controlled means (146 to 170) for adjusting a limit orientation of the arm (8) around the axis of articulation (11) relative to the frame (110), corresponding to a maximum approximation of the main axis (14) relative to the frame (110) and to maximum stress on the means (152) of elastic stress.  14. Self-propelled vehicle according to any one of claims 9 to 13, characterized in that it comprises several wheel devices (7) according to any one of claims 1 to 8, whose respective supports (8) are carried by the frame (10, 110) and whose main axes (14) have fixed directions relative to the frame (10, 110) and perpendicular to the same own longitudinal direction (5, 105) thereof.  15. Self-propelled vehicle according to claim 14, characterized in that the motor means (44 to 47, 49 to 58) comprise a controlled propulsion motor (57) common to several wheel devices (7) and means (44 to 47 , 49 to 56, 58) of kinematic connection between the controlled propulsion motor (57) and each of these wheel devices (7), comprising respective means (53) for authorizing a rotational speed differential between the respective means ( 19).  16. Self-propelled vehicle according to any one of claims 14 and 15, characterized in that, with a view to exploring pipes (102) of which an internal face (103) constitutes the rolling area, the framework (110 ) includes  - two load-bearing modules (here, 112), mutually juxtaposed longitudinally,  - means (115, 119, 120) of mutual articulation of said carrier modules (111, 112) around a determined longitudinal axis (116),  - controlled means (122 to 129, 171, 172) for relative angular positioning of the carrier modules (111, 112) around said longitudinal axis (116),  and in that each carrier module (111, 112) carries the respective supports (8) of at least three wheel devices (7) according to any one of claims 1 to 8, distributed angularly around said longitudinal axis (116) , the means (60 to 89) of controlled immobilization of the rollers (28) of the wheel devices (7) of one of the carrier modules (111, 112) relative to their hub (19) being independent of the means (60 89) for controlled immobilization of the rollers (28) of the wheel devices (7) of the other carrier module (111, 112) with respect to their hub (19).  17. Self-propelled vehicle according to claim 16, characterized in that the means (115, 119, 120) of mutual articulation of the two carrier modules (111, 112) comprise a central module (115), interposed longitudinally between the two carrier modules (111, 112) and on which each of these is articulated around said longitudinal axis (116), and in that the controlled means (122 to 129, 171, 172) for relative angular positioning of the carrier modules (111, 112) comprise respective controlled means (122 to 129, 171, 172) for angular positioning of each of them relative to the central module (113), around said longitudinal axis (116).  18. Self-propelled vehicle according to any one of claims 16 and 17 in combination with any one of claims 12 and 13, characterized in that, from the respective axis of articulation (11), the arms (8 ) correspond to each carrier module (111, 112) are oriented in the longitudinal direction of a distance from the other carrier module and diverge mutually in this direction at least in a deployment orientation occupied in particular during the longitudinal progression of the vehicle (101).  19. Self-propelled vehicle according to claim 18 or according to any one of claims 16 and 17 in combination with any one of claims 12 and 13, characterized in that the respective axes of articulation (11) of the arms (8) on the corresponding corresponding carrier module (111, 112) are located in the same respective transverse plane (130, 131), perpendicular to the longitudinal axis (116), and in that the arms (8) and the wheels (13) are respectively mutually identical.  20. Self-propelled vehicle according to claim 19, characterized in that each carrier module (111, 112) comprises controlled means (146 to 170), common to the corresponding wheel devices (7), for adjusting the same limit orientation of the arms ( 8) of the latter around the respective axis (11) of articulation, relative to this module (111, 112), this limit orientation corresponding to maximum approximation of the respective main axis (14) relative to the longitudinal axis (116) and at maximum stress on the respective means (152) of elastic stress.  21. Self-propelled vehicle according to any one of claims 16 to 20, characterized in that each carrier module (111, 112) comprises a controlled propulsion motor (57) common to the corresponding wheel devices.  22. Self-propelled vehicle according to any one of claims 16 to 21, characterized in that each carrier module (111, 112) carries the respective supports (8) of three wheel devices (7) according to any one of claims 1 to 8, mutually identical and regularly distributed angularly around said longitudinal axis (116).