Rolling device for a land vehicle

Description

TECHNICAL FIELD

[0001] The invention relates to a rolling device, as well as to a vehicle comprising at least one such rolling device. The field of the invention relates to a rolling device intended to roll on a rolling support such as the ground for example.

[0002] The invention is in the field of land transport and applies to all types of land transporters such as heavy load transporters (public works, mining industry, agriculture, forestry industry), all-terrain transporters, etc. STATE OF THE PRIOR ART

[0003] It is known to use a rolling device that deforms and adapts to the geometry of the rolling support on which it rolls, in order to maximize the contact surface.

[0004] Document US1887544 describes a rolling device for a land vehicle, where the rolling device comprises an axle, two rims mounted on the axle and each rim carries a tire. The axle carries a flange on which a plurality of rotating ball joints are mounted and each ball joint supports a rod which passes through said rotating ball joint. Each end of each rod is secured to a ball joint. The rims are arranged on either side of the flange and each rim is mounted articulated on the ball joints fixed to the ends of the rods.

[0005] When the vehicle is traveling at high speed, the movements of the rims can be hindered by inertial effects which can be detrimental to the proper functioning of the rolling device, such as unbalance or vibrations.

[0006] To avoid these phenomena, document US1887544 provides a locking system which prevents articulation at the level of the rotating ball joints, thus blocking the movement between the two rims.

[0007] One difficulty with the rolling arrangement of US1887544 is that stones or objects can get stuck between the rims. To overcome this difficulty, it is then possible to reduce the clearance between the tires, but in this case, this limits the ability to adapt to a curved rolling support.

[0008] Another difficulty arises when the rolling device is blocked and the rolling device encounters an obstacle requiring its articulation.

[0009] Another difficulty is that the rims do not automatically return to a coaxial position after passing over a curved road surface. The rims can then be offset in the direction of travel of the vehicle.

[0010] Document BE-A-396 649 discloses a state-of-the-art rolling device comprising: a radial support capable of rotating around a direction of rotation, at least two wheels arranged around the direction of rotation and arranged on either side of the radial support, where each wheel is movable between a centered position in which the axis of the wheel is coaxial with the direction of rotation and an off-center position in which the axis of the wheel is eccentric and parallel to the direction of rotation, at least two rods extending in a longitudinal direction, where each rod passes through a first housing of the radial support where it is tiltable relative to the radial support, where for each rod, each wheel has a second housing where said rod is tiltable relative to the wheel, and for at least one wheel, at least one control system provided to take a rest position when the wheel is in the centered position and an activation position when the wheel is in the off-center position, or in the activation position,the at least one control system tends to return the wheel to its centered position.

[0011] An object of the present invention is to provide a rolling device for a land vehicle where the rolling device is adaptable according to the rolling support while ensuring a minimal gap between the wheels, and where the rolling device comprises a control system which makes it possible to resolve the possible problems of vibrations and non-coaxiality of the state of the art.

[0012] For this purpose, a rolling device is proposed comprising: a radial support capable of rotating about a direction of rotation, at least two wheels arranged about the direction of rotation and arranged on either side of the radial support, where each wheel is movable between a centered position in which the axis of the wheel is coaxial with the direction of rotation and an off-center position in which the axis of the wheel is eccentric and parallel to the direction of rotation, at least two rods extending in a longitudinal direction, where each rod passes through a first housing of the radial support where it is tiltable relative to the radial support, where for each rod, each wheel has a second housing where said rod is tiltable relative to the wheel, and through which said rod is capable of sliding in translation in the longitudinal direction, for each wheel, guide means provided to guide said wheel in a plane perpendicular to the direction of rotation, and for at least one wheel,at least one control system provided to take a rest position when the wheel is in the centered position and an activation position when the wheel is in the off-center position, where in the activation position, the at least one control system tends to return the wheel to its centered position.

[0013] Such a control system equipping the rolling device makes it possible, among other things, to limit vibrations due to rapid movements of the wheels and a return to the coaxial position after an offset.

[0014] Advantageously, the guide means comprise at least three shoes secured to the wheel and two lateral flanges secured to the radial support and arranged on either side of the wheel and at least three spacers fixed between the two lateral flanges and each shoe is capable of bearing alternately by one of its ends against one of the lateral flanges or by the other of its ends against the other of the lateral flanges.

[0015] Advantageously, each control system comprises a cage fixed to the wheel and delimiting an interior volume between the two lateral flanges, a puck housed in said interior volume and made of a flexible material and for each puck, a spacer crosses said puck at the level of a central bore which it has for this purpose.

[0016] Advantageously, each shoe constitutes a cage.

[0017] Advantageously, a space is provided between the puck and each side flange.

[0018] Advantageously, the puck is fixed by its outer peripheral surface to the cage and fixed by its central bore to the spacer.

[0019] Advantageously, the puck has additional holes in relation to the central bore and / or bosses.

[0020] Advantageously, each first housing is fixed in a hole of the radial support at a median zone of said hole, and the hole has an axis parallel to the direction of rotation and has on either side of the median zone a truncated cone shape whose small base is oriented towards the median zone and whose large base is oriented in the opposite direction.

[0021] Advantageously, the rolling device comprises a hub capable of rotating around the direction of rotation, the radial support is integral with the hub and arranged around the hub.

[0022] The invention also proposes a land vehicle comprising a chassis and a plurality of rolling devices according to one of the preceding variants where each rolling device is mounted to be able to rotate on the chassis around the direction of rotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above-mentioned and other features of the invention will become more clearly apparent from the following description of an exemplary embodiment, said description being made in relation to the accompanying drawings, among which: Fig. 1 is a perspective view of a rolling device according to the invention, Fig. 2 is a view identical to that of the Fig. 1 for which a side plate has been removed, Fig. 3 is a sectional view of the rolling device of the Fig. 1 by plane III containing the axis of rotation X, and Fig. 4 is a view similar to that of the Fig. 3 for an alternative embodiment of the invention. DETAILED PRESENTATION OF EMBODIMENT METHODS

[0024] There Fig. 1 and the Fig. 2 show a rolling device 100 of the land wheel type which can equip a land vehicle. The land vehicle comprises a chassis and a plurality of rolling devices 100. Each rolling device 100 is mounted so as to be able to rotate on the chassis about a direction of rotation X. The fixing of the rolling device 100 is ensured here by a socket 102. For example, each rolling device 100 is fixed to one end of an axle of the vehicle via the socket 102.

[0025] There Fig. 3 shows a section of a first embodiment of the rolling device 100 with a hub 104 and the Fig. 4 shows a section of a second embodiment of the rolling device 100 without hub 104 which makes it possible to lighten the rolling device 100 and to free up space in the center of said rolling device 100.

[0026] The rolling device 100 comprises a radial support 110 which here consists of three integral bushings. The radial support 110 is capable of rotating around the direction of rotation X which is here horizontal.

[0027] In the embodiment of the invention presented in the Fig. 3 , the rolling device 100 comprises a hub 104 capable of rotating around the direction of rotation X where the radial support 110 is integral with the hub 104 and arranged around the hub 104. In a particular embodiment, the hub 104 is integral with the axle by the socket 102 which is integral with the hub 104.

[0028] Here, the radial support 110 is integral with a central sleeve 111 which is itself made integral with the hub 104 by means of a key 113 and, thus, any rotation of the hub 104 around the direction of rotation X causes the radial support 110 to rotate in the same way.

[0029] In the embodiment of the invention presented to the Figs. 3 And 4 , the radial support 110 consists of three bushings distributed at 120° around the direction of rotation X.

[0030] The rolling device 100 comprises at least two wheels 108 arranged around the direction of rotation X and around the hub 104 in the first embodiment of the invention. The wheels 108 are arranged on either side of the radial support 110.

[0031] In the embodiment shown on the Figs. 1 à 4 , each wheel 108 consists of a rim and a tire 106 which is mounted around the rim and which is intended to roll on an exterior surface such as for example the ground. But according to another embodiment not shown, the wheel 108 may not have a tire and the wheel 108 is then constituted only of a rim for example in the case of movement on ice.

[0032] In the embodiment of the invention presented to the Figs. 3 And 4 , there are two 108 wheels, but it is possible to have more than two.

[0033] The wheels 108 are arranged next to each other along the direction of rotation X and distributed on either side of the radial support 110.

[0034] For each wheel 108, the rolling device 100 comprises two lateral flanges 124a-b secured to the radial support 110 and rotating with it and arranged on either side of the wheel 108.

[0035] In each embodiment of the invention, one of the side plates 124a is fixed to the radial support 110 and the other of the side plates 124b is fixed to the first side plate 124a by means of fixing means 156 described below.

[0036] In the first embodiment of the invention, the side flange 124a is further fixed to the hub 104 by means of the central sleeve 111.

[0037] The rolling device 100 comprises at least two rods 112 which here number three as can be seen in the Fig. 2 . Each rod 112 extends parallel to a longitudinal direction X' which in the embodiment of the invention shown in the Fig. 3 is parallel to the direction of rotation X, but which, in operation, can tilt relative to the direction of rotation X. According to the general case, there are at least two rods 112 preferably distributed equiangularly around the direction of rotation X, for example here at 120°.

[0038] For each rod 112, the radial support 110 comprises a first housing 114 which is crossed by the rod 112 and in which said rod 112 is tiltable relative to the radial support 110.

[0039] In the embodiment of the invention presented in the Fig. 3 and to the Fig. 4 , in each first housing 114, is mounted a first ball joint 116 which has a first bore passing through it and the rod 112 is mounted fixed in said first bore. Each first ball joint 116 is thus retained in the first housing 114 and free in articulation and in rotation about the longitudinal direction X' in said first housing 114. Each rod 112 is thus mounted articulated and fixed in translation in the first housing 114.

[0040] Each rod 112 protrudes on either side of the radial support 110 and has a first end which protrudes on one side of the radial support 110 and a second end which protrudes on the other side of the radial support 110.

[0041] For each rod 112, each wheel 108 comprises a second housing 118 through which said rod 112 passes and in which said rod 112 is tiltable relative to the wheel 108, and where said rod 112 is able to slide in translation along the longitudinal direction X' when said rod 112 is tilted. Each rod 112 is thus mounted articulated and free in translation in the second housing 118.

[0042] In the embodiment of the invention presented to the Figs. 3 And 4 , in each second housing 118, is mounted a second ball joint 120 which has a second bore passing through it and the end of the rod 112 is mounted in said second bore so as to be able to slide parallel to the longitudinal direction X'. Each second ball joint 120 is thus retained in the second housing 118 and free in articulation and rotation around the longitudinal direction X' in said second housing 120.

[0043] One wheel 108 thus receives the first end of each rod 112 and the other wheel 108 receives the second end of each rod 112.

[0044] Thus, when one of the tires 106 encounters an obstacle on the ground or the ground has a slope, the two tires 106 shift vertically relative to each other and each rod 112 becomes offset relative to the direction of rotation X and the longitudinal direction X' tilts relative to the direction of rotation X.

[0045] Due to the freedom of translation at the level of the second housings 118, each rod 112 can move relative to the wheels 108 parallel to the longitudinal direction X'.

[0046] For each rod 112, the lateral flanges 124a which are between the two flanges 124b arranged at the two extreme positions have windows through which the rod 112 passes.

[0047] In the embodiment of the Fig. 3 , each wheel 108 here has a central hole 122 in its center to allow the hub 104 to pass through and the dimensions of the central hole 122 are such that when the wheel 108 moves, it does not come into contact with the hub 104.

[0048] For each wheel 108, the rolling device 100 comprises guide means which guide said wheel 108 in a plane perpendicular to the direction of rotation X. Thus, even when the tires 106 shift vertically, they do not move away from each other horizontally.

[0049] Each wheel 108 is guided by plane contacts between said wheel 108 and the lateral flanges 124a-b which are on either side of the wheel 108.

[0050] According to a particular embodiment, the guide means comprise the two lateral flanges 124a-b arranged on either side of the wheel 108 and at least three spacers 156 fixed between the two lateral flanges 124a-b in order to guarantee the distance between the latter.

[0051] The guide means also comprise at least three shoes 152 fixed to the wheel 108 and each is capable of bearing alternately by one of its ends against one of the lateral flanges 124a or by the other of its ends against the other of the lateral flanges 124b. The guide means then consist of the shoes 152 and the lateral flanges 124a-b. Depending on the movement of the wheel 108 between the lateral flanges 124a-b, each shoe 152 will be able to bear against one or the other of the lateral flanges 124a-b to guide the wheel 108. When stationary, the gap between the shoe 152 and the lateral flange 124a-b is for example of the order of 0.1 mm. The arrangement between the side plates 124a-b and the shoes 152 ensures bilateral flat support of the wheel 108 against the side plates 124a-b.

[0052] Each wheel 108 is thus movable between a centered position and an off-center position. In the centered position, the axis of the wheel 108 is coaxial with the direction of rotation X and in the off-center position, the axis of the wheel 108 is eccentric and parallel to the direction of rotation X. When at least one of the wheels 108 is in an off-center position, the rods 112 are inclined. There are several off-center positions depending on the vertical offset between the wheels 108, i.e. the offset perpendicular to the direction of rotation X.

[0053] Thus, when the rolling device 100 rolls on an exterior surface which presents an obstacle or a slope, the rods 112, on the one hand, tilt and, on the other hand, translate in the second ball joints 120 in the longitudinal direction X', the wheels 108 slide vertically relative to each other to adapt to the shape of the exterior surface.

[0054] In the embodiment of the invention presented in the Fig. 3 , each ball joint 116, 120 takes the form of a ball crossed by a bore and where the housing 114, 118 takes the form of a ring comprising an internal sliding surface in the form of a portion of a sphere, in which the ball is retained rotatably.

[0055] The rods 112 can be rigid or flexible, which allows greater vertical movement of the wheels 108.

[0056] In each embodiment of the invention presented here, there is a wheel 108 on each side of the radial support 110, but it is possible to have several wheels 108 on each side of the radial support 110. For each rod 112, each wheel 108 then has a second ball joint and the rod 112 successively passes through the second ball joint attached to each wheel 108. There are thus several second ball joints along each rod 112. For each wheel 108, the rolling device 100 then comprises guide means which ensure, among other things, a translation perpendicular to the direction of rotation X.

[0057] According to a particular embodiment in the case where there are several wheels 108 on each side, for a wheel 108, the guide means comprise two lateral flanges arranged on either side of the wheel 108 and fixed to the radial support 110 and shoes 152 fixed to the wheel 108 and bearing alternately by one of their ends against one of the lateral flanges 124 or by the other of their ends against the other of the lateral flanges 124.

[0058] According to a particular embodiment in the case where there are several wheels 108 on each side, the flanges of a wheel 108 are the wheels 108 which are on either side of said wheel 108.

[0059] Generally speaking, the rolling device 100 comprises for at least one wheel 108, at least one control system 150. In the embodiment of the invention presented in Figs. 2 à 4 , there are three control systems 150 per wheel 108. The three control systems 150 are distributed equiangularly around the direction of rotation X, here at 120° and offset by 60° relative to the rods 112.

[0060] In another embodiment not shown, there may be a single control system 150 on a single wheel 108. Indeed, as the wheels 108 are linked by the rods 112, the action of the control system 150 on one wheel 108 is transmitted to the other wheel 108.

[0061] When the rolling device 100 is rolling, for each wheel 108 which is in the centered position, each control system 150 associated with said wheel 108 is in the rest position, and for each wheel 108 which is in the off-center position, each control system 150 associated with said wheel 108 is in the activation position.

[0062] Thus, when a wheel 108 alternately passes from the centered position to an off-center position, each control system 150 associated with said wheel 108 alternately passes from the rest position to the activation position.

[0063] In the rest position, the control system 150 does not exert any force on the associated wheel 108 perpendicular to the direction of rotation X.

[0064] In the activated position, the control system 150 exerts forces on the associated wheel 108 perpendicular to the direction of rotation X, where these forces tend to return the wheel 108 to its centered position. Each control system 150 thus introduces stiffness and damping into the rolling device 100 when the wheels 108 move relative to each other. Such a control system 150 then makes it possible to limit vibrations due to rapid movements of the wheels and a return to the coaxial position after an offset.

[0065] In the embodiments of the invention of the Figs. 3 And 4 , each control system 150 comprises a cage 152 fixed to the wheel 108 and delimiting an interior volume which is here of cylindrical shape with an axis parallel to the direction of rotation X, and which is also delimited between the two lateral flanges 124a-b on either side of the wheel 108.

[0066] In the embodiments of the invention of the Figs. 3 And 4 , each cage 152 constitutes a shoe of the guide means, but in another embodiment not shown, the cage and the shoe can constitute separate elements.

[0067] Each control system 150 also includes a puck 154 housed in the interior volume of the cage 152 and made of a flexible material which has a stiffness and a damping coefficient which depends in particular on the weight of the vehicle, its speed, the vibration frequencies, etc.

[0068] For each puck 154, a spacer 156 passes through a puck 154 at a central bore that the latter has for this purpose, but there may be more spacers 156 than pucks 154.

[0069] According to a particular embodiment, the puck 154 is made of an elastomer such as, for example, the product manufactured by the company Berleburger under the name “Regufoam ®< 190 plus”. In the embodiment of the invention presented here, the puck 154 is cylindrical and pierced with the central bore.

[0070] The puck 154 is housed between the side plates 124a-b, in the cage 152.

[0071] According to a particular embodiment, the puck 154 is fixed by its outer peripheral surface to the cage 152, and fixed by its central bore to the spacer 156. The fixing can be carried out for example by gluing and makes it possible to influence the stiffness and damping characteristics of the control system 150.

[0072] According to another particular embodiment, the puck 154 comprises additional holes relative to the central bore and / or bosses to influence the stiffness and damping characteristics of the control system 150.

[0073] In the embodiments of the invention presented in Figs. 3 And 4 , each spacer 156 comprises a threaded rod 158 with a first shoulder which bears against an inner face of one of the side plates 124a and a second shoulder which bears against an inner face of the other of the side plates 124b. The inner faces are the faces of the side plates 124a-b which are opposite each other and which are therefore opposite the puck 154. The two shoulders also make it possible to guarantee the spacing between the two side plates 124a-b.

[0074] The threaded rod 158 projects beyond each side flange 124a-b and, for each end of the threaded rod 158, the spacer 156 comprises a nut 160a-b which is screwed onto said end and clamps each side flange 124 against one of the shoulders.

[0075] In the embodiments of the invention presented to the Figs. 3 And 4 , it is the threaded rod 158 which passes through the puck 154.

[0076] When the wheel 108 moves vertically, the cage 152 moves in the same way by compressing the puck 154 which is held in position against the threaded rod 158 and which tends to return to its initial configuration due to its elasticity.

[0077] To allow free deformation of the puck 154 when moving into the activation position, a space 162 is provided between the puck 154 and each lateral flange 124a-b delimiting the interior volume where the puck 154 is housed.

[0078] In the embodiment of the invention, the radial support 110 does not carry a tire, but it is also possible to provide that the radial support 110 constitutes a wheel for a tire.

[0079] In the embodiment of the invention presented on the Figs. 3 And 4 , each first housing 114 is fixed in a hole 126 of the radial support 110 at a median zone of said hole 126. The hole 126 has an axis parallel to the direction of rotation X and has on either side of the median zone a truncated cone shape whose small base is oriented towards the median zone and whose large base is oriented in the opposite direction. The truncated cone shape makes it possible to limit the angular movement of the rods 112.

[0080] In the embodiment of the Fig. 3 , the rolling forces and the torque coming from the axle are transmitted to different parts and in particular successively to the hub 104, to the radial support 110, to the rods 112 and finally to the wheels 108.

[0081] In the embodiment of the Fig. 4 where the hub 104 is not present, the socket 102 is fixed directly to one of the side flanges 124b arranged at an extreme position. The rolling forces and the torque coming from the axle are then transmitted to different parts and in particular successively through the side flange 124b, the spacers 156, the side flange 124a, the radial support 110, the rods 112 and finally the wheels 108. The absence of the hub 104 makes it possible to lighten the rolling device 100 and to further reduce the weight, it is possible to make recesses in the side flanges 124a-b and the wheels 108

Claims

1. Rolling device (100) comprising: - a radial support (110) able to turn about a rotation direction (X), - at least two wheels (108) disposed around the rotation direction (X) and disposed on either side of the radial support (110), wherein each wheel (108) is able to move between a centred position in which the axis of the wheel (108) is coaxial with the rotation direction (X) and a decentred position in which the axis of the wheel (108) is off-centre and parallel to the rotation direction (X), - at least two rods (112) extending in a longitudinal direction (X'), wherein each rod (112) passes through a first housing (114) of the radial support (110) where it is inclinable with respect to the radial support (110), wherein, for each rod (112), each wheel (108) has a second housing (118) where said rod (112) is inclinable with respect to the wheel (108), and through which said rod (112) is able to slide in translation in the longitudinal direction (X'), - for each wheel (108), guidance means provided for guiding said wheel (108) in a plane perpendicular to the rotation direction (X), and - for at least one wheel (108), at least one control system (150) provided for adopting an idle position when the wheel (108) is in a centred position and an activation position when the wheel (108) is in a decentred position, wherein, in the activation position, the at least one control system (150) tends to return the wheel (108) to its centred position.

2. Rolling device (100) according to claim 1, characterised in that the guidance means comprise at least three shoes (152) secured to the wheel (108) and two lateral flanges (124a-b) secured to the radial support (110) and disposed on either side of the wheel (108), and at least three struts (156) secured between the two lateral flanges (124a-b), and in that each shoe (152) is able to come into abutment alternatively through one of its ends against one of the lateral flanges (124a) or through the other of its ends against the other one of the lateral flanges (124b).

3. Rolling device (100) according to claim 2, characterised in that the or each control system (150) comprises a cage (152) secured to the wheel (10) and delimiting an interior volume between the two lateral flanges (124a-b), a blade (154) housed in said interior volume and produced from a flexible material, and in that, for each blade (154), a strut (156) passes through said blade (154) at a central bore that the latter has for this purpose.

4. Rolling device (100) according to claims 2 and 3, characterised in that each shoe (152) constitutes a cage (152).

5. Rolling device (100) according to one of claims 3 or 4, characterised in that a space (162) is provided between the blade (154) and each lateral flange (124a-b).

6. Rolling device (100) according to one of claims 3 to 5, characterised in that the blade (154) is secured by its exterior peripheral surface to the cage (152) and secured by its central bore to the strut (156).

7. Rolling device (100) according to one of claims 3 to 6, characterised in that the blade (154) comprises additional piercings with respect to the central bore and / or protrusions.

8. Rolling device (100) according to one of claims 1 to 7, characterised in that each first housing (104) is secured in a hole (126) of the radial support (110) at a median zone of said hole (126), and in that the hole (126) has an axis parallel to the rotation direction (X) and has, on either side of the median zone, the form of a truncated cone the small base of which is oriented towards the median zone and the large base of which is oriented in the opposite direction.

9. Rolling device (100) according to one of claims 1 to 8, characterised in that it comprises a hub (104) able to turn about the rotation direction (X), and in that the radial support (110) is secured to the hub (104) and disposed around the hub (104).

10. Land vehicle comprising a chassis and a plurality of rolling devices according to one of the preceding claims, wherein each rolling device is mounted so as to be able to rotate on the chassis about the rotation direction (X).