Track widener for inflating / deflating tyres of a vehicle

Abstract

The invention relates to a track widener (1) comprising: - a movable part (2) able to be fastened between a first component (3) and at least one second component (4) which are able to rotate about an axis of rotation (R) of a mounted assembly of a vehicle, the movable part (2) having an axis of rotation (R) intended to be coaxial with the axis of rotation (R) of the mounted assembly, - a static part (7) able to be connected to at least one fixed element of the vehicle, - a system (8) for guiding the rotational movement between the movable part (2) and the static part (7). According to the invention, it further comprises: - an air seal system (9) defining a chamber (10) between the movable part (2) and the static part (7), - at least one main fluid duct (11) formed in the static part (7) and opening, on the one hand, into the chamber (10) and, on the other hand, outside the track widener (1), - at least one secondary fluid duct (12) formed in the movable part (2) and opening, on the one hand, into the chamber (10) and, on the other hand, outside the widener.

Description

Wheel spacer for inflating / deflating vehicle tires technical field

[0001] The invention relates to the technical field of centralized tire inflation systems for a vehicle, known by the acronym "CTIS" from the English term "Central Tire Inflation System". Previous art

[0002] It is known from the prior art of CTIS to allow adjustment of the tire pressure of the wheels of a vehicle, when it needs to be adapted to driving conditions.

[0003] For example, a vehicle driving on soft ground must have low tire pressure to maximize traction and allow the vehicle to move forward.

[0004] Once the soft ground has been crossed, it is advisable to increase the tire pressure so that the vehicle can travel at a higher speed, for example when the vehicle joins a road.

[0005] CTIS systems typically include rotating joints that connect each tire on the vehicle to a compressed air supply and an exhaust system. This allows tire pressure to be adjusted, either up or down, without having to manipulate individual tires. In particular, pressure adjustments can be made while the vehicle is in motion.

[0006] Vehicle-mounted fuel injection systems (CTIS) are becoming increasingly common, particularly for 4x4 and all-terrain vehicles. Some of these vehicles are equipped with them from the design stage, or are pre-engineered with features such as a sealed fuel line leading to the vehicle's wheel. When a vehicle is pre-equipped for a CTIS, it is generally already fitted with rotary seals. A fuel supply valve with the rotary seal is then installed between the end of this sealed fuel line, which is usually fixed to the vehicle, and the wheel, which rotates around its axis.

[0007] CTIS adaptation systems have been developed for vehicles lacking any complete or partial installation. These systems typically consist of a fuel valve mounted in the center of the wheel and connected to a sealed conduit fixed to the vehicle. However, the limited space in the wheel well often necessitates positioning this fuel valve on the exterior of the vehicle, which, besides being unsightly, is detrimental to the durability of the fuel valve or conduit, potentially rendering the CTIS inoperative.

[0008] Similarly, this supply valve is equipped with a rotating seal to ensure the valve rotates with the wheel, while the fluid supply line is fixed. This prototype solution still needs to be adapted to each vehicle, which is tedious and expensive.

[0009] Documents WO2011015368A1, EP2647511A2, and WO2014022265A1 describe CTIS designs that are not entirely satisfactory. The design described in these documents does not guarantee a long service life or good performance of the rotary joint. Description of the invention

[0010] One of the aims of the invention is to overcome the disadvantages of the prior art, by proposing additional equipment on the vehicle allowing the installation and operation of a tire inflation / deflation system, interoperable on any type of vehicle and resolving the reliability and aesthetic problems caused by direct adaptation to the wheel.

[0011] To this end, a wheel widening device was developed comprising: - a movable part capable of being fixed between a first component and at least one second component that is movable and rotates around an axis of rotation of a vehicle assembly, the movable part having an axis of rotation intended to be coaxial with the axis of rotation of the assembly, - a static part capable of being attached to at least one fixed element of the vehicle, - a system for guiding the rotational movement between the moving part and the static part.

[0012] According to the invention, the wheel spacer comprises: - an airtight system defining a chamber between the moving part and the static part, - at least one main fluid conduit provided in the static part and opening, on the one hand, into the chamber and, on the other hand, to the outside of the track widener, - at least one secondary fluidic conduit provided in the moving part and opening, on the one hand, into the chamber and, on the other hand, to the outside of the track widener.

[0013] From the above, the additional equipment enabling the installation and operation of a tire inflation system takes the form of a wheel spacer.

[0014] Therefore, the spacer is positioned inside the vehicle's wheel so that it is protected from external damage and is not visible, thus not hindering the overall aesthetics of the vehicle.

[0015] Furthermore, since the wheel spacer is mounted between two rotating components of the vehicle, this ensures better dynamic balancing compared to existing solutions mounted at the axial end of the rotating components. This feature also allows for better control of the coaxiality of the various rotating parts.

[0016] The wheel spacer according to the invention is mounted between existing vehicle components and does not require any major modification of these components, so it is simple to implement.

[0017] The end of at least one main fluidic conduit opening outside the enlarger allows connection of a supply valve linked to a compressed air supply circuit of the vehicle so that the invention is adaptable to all types of vehicles.

[0018] Since the end of at least one secondary fluidic conduit opening outside the spacer rotates with the wheel, it is possible to connect this end to the fluidic cavity formed by the rim and the tire.

[0019] Thus, all the components, the wheel, and the tire, are animated by the same rotational movement so that the end pieces, positioned one at the said end of the secondary fluidic conduit opening to the outside of the enlarger, and the other at the inlet of the fluidic cavity, are not equipped with rotating systems. This then makes it possible to reduce costs and improve endurance.

[0020] Preferably, the guide system is positioned radially to the axis of rotation of the moving part, either internally or externally, relative to the sealing system. This improves the quality of rotation of the moving part relative to the stationary part by providing better coaxiality. It also reduces mechanical stress on the sealing system and the risk of air leakage.

[0021] Furthermore, in the configuration where the guidance system is radially further from the axis of rotation than the sealing system, this ensures a compact geometry of the track widener.

[0022] The guidance system implemented is of any suitable type, for example in the form of a ball bearing with one or more rows of balls, a needle bearing, a roller bearing, a self-lubricating bearing, a bushing, or any other suitable guidance system.

[0023] The sealing system is of any suitable type, and may be in the form of lip rings, V-shaped seals, O-rings, four-lobe seals, cassette seals, or any other suitable sealing system.

[0024] According to a particular embodiment, the minimum cross-section of the main fluidic conduit, when there is only one, or the sum of the minimum cross-sections of the main fluidic conduits, when there are several, is between 10 and 200 mm 2 , preferably between 20 and 150 mm 2 , and very preferably between 25 and 90 mm 2 .

[0025] Each main fluid passage has a minimum cross-section, which is the smallest fluid passage perpendicular to the fluid path defined by the main fluid passage. Whether the main fluid passage is single or multiple, the total minimum cross-section of the main fluid passage network must fall within the aforementioned limits. This defines the ease of compressed air flow through the fluid passage network to the annular chamber and determines the mechanical stresses in the static section. Using multiple fluid passages ensures inflation / deflation functionality even in the event of an unfortunate blockage of a fluid passage.

[0026] Preferably, the static part of the wheel spacer includes a single main fluidic conduit, which allows for only one connection between the wheel spacer and a compressed air reservoir, without a rotary joint, already present in the vehicle.

[0027] Preferably, the minimum cross-sectional area of ​​the secondary fluidic conduit, when there is only one, or the sum of the minimum cross-sectional areas of the secondary fluidic conduits, when there are several, is equal to the minimum cross-sectional area of ​​the single primary fluidic conduit or to the sum of the minimum cross-sectional areas of the primary fluidic conduits. Thus, maintaining a constant cross-sectional area between the static and moving parts, which are connected in series, allows for better fluid circulation.

[0028] Advantageously, the moving part includes at least two secondary fluidic channels, regularly spaced angularly around the axis of rotation, to ensure better mass distribution and balance of the moving part, since it is subject to rotational motion. This also improves the durability of the moving components around the axis of rotation of the assembled unit.

[0029] A minimum cross-section of each secondary fluidic conduit is greater than 5 mm 2 .

[0030] In one particular embodiment, the secondary fluidic conduit opens outside the expander at the axis of rotation of the moving part, thus ensuring better dynamic balance on the moving part since it is in rotational motion. This also improves the durability of the moving components around the axis of rotation of the assembled unit.

[0031] Advantageously, a smaller axial dimension of the moving part of the widener, that is to say along the axis of rotation, between a first bearing face of the first component and a second bearing face of at least one second component is less than 120 mm, preferably less than 60 mm, and very preferably less than 30 mm.

[0032] This feature allows for the quantification of the maximum axial offset of the assembled component relative to its initial position before the wheel spacer is installed. The smaller the offset, the better the mechanical endurance of the vehicle and its rotating guide elements, such as ball bearings. This minimizes the structural modifications required on the vehicle to install the spacer according to the invention.

[0033] The invention also relates to a vehicle comprising a wheel spacer according to one of the aforementioned characteristics, mounted between a first component and a second component, which are free to rotate about an axis of rotation of a vehicle assembly, selected from a group comprising: a brake disc, an axle, a hub, a spindle, bearings, a second wheel spacer already present, etc. This selection simplifies the vehicle mounting system by using pre-existing vehicle components, thereby reducing bulk and limiting costs.

[0034] The invention also relates to a method of fixing a wheel spacer according to one of the aforementioned characteristics, between a first component and at least one second component, which are movable in rotation around an axis of rotation of a vehicle assembly.

[0035] According to the invention, the attachment of the moving part to the second component is achieved using a fastening system initially present on the vehicle and previously intended to fix the mounted assembly, the mounted assembly being fixed securely to the rotating moving part of the widener by a similar fastening system. Brief description of the drawings

[0036] [Fig.1] is a longitudinal cross-sectional view of the wheel spacer according to the invention mounted between a rim and a hub of a vehicle assembly, the cross-section passing through the main and secondary fluidic channels.

[0037] [Fig.2] is a longitudinal cross-sectional view of the wheel spacer similar to that in Figure 1, the section passing through the means of fixing the moving part to the first and second moving components of the vehicle. Detailed description of the invention

[0038] With reference to figures 1 and 2, the invention relates to a wheel spacer (1) intended to be mounted on a vehicle and enabling the installation and operation of a tire inflation system known by the acronym "CTIS" from the anglicism "Central Tire Inflation System".

[0039] The wheel spacer (1) comprises a movable part (2), in particular in the form of a disc having a cylindrical central bearing surface, intended to be fixed between a first component (3) and a second component (4) of the vehicle, both of which are free to rotate about an axis of rotation (R) of a mounted assembly of the vehicle. The movable part (2) is fixed between the two components (3, 4) and has an axis of rotation (R) coaxial with that of the components (3, 4).

[0040] In the embodiment illustrated in the figures, the movable part (2) of the wheel spacer (1) is fixed between a rim, as the first component (3), and a hub, as the second component (4), carrying a brake disc and initially intended to receive the rim.

[0041] To this end, the cylindrical bearing surface of the movable part (2) is engaged and centered in a central bore of the rim, and includes first holes regularly distributed around the axis of rotation (R) into which are inserted first studs (5) projecting from the hub, which were initially used to fix the rim. Nuts are screwed around the first studs (5) and integrated into the thickness of the movable part (2), to fix said movable part (2) to the hub.

[0042] On the other hand, the moving part (2) is fixed to the rim by means of second studs (6), added and passing through second holes regularly distributed around the axis of rotation (R) of the moving part (2), and protruding on the side of the rim to pass through complementary holes initially present in the rim, all tightened by means of nuts.

[0043] The movable part (2) is attached to the second component (4) using a fastening system already present on the vehicle and previously intended to secure the assembled unit. This assembled unit is fixed to the rotating movable part (2) of the wheel spacer by a similar fastening system, namely nuts and studs. The assembly is simple and reliable, and requires no major structural modifications to the vehicle's components (3, 4).

[0044] The wheel spacer (1) also includes a static part (7), for example in the form of a ring, inserted into an annular groove formed in the movable part (2) around the axis of rotation (R) from a face opposite the hub. The static part (7) is, in a manner known in a wheel spacer (1), capable of being connected to at least one fixed element of the vehicle to remain static.

[0045] To ensure efficient guidance of the rotational movement of the moving part (2) relative to the static part (7), a guide system (8) is mounted radially around the axis of rotation (R) between the static part (7) and the moving part (2), specifically bearing against an outer face of the static part (7) relative to the axis of rotation (R). Cantilevered mountings, which are less efficient, are avoided.

[0046] An air sealing system (9) is positioned radially around the axis of rotation (R) between the static part (7) and the moving part (2), supported against at least one inner face of the static part (7) with respect to the axis of rotation (R), and defines a chamber (10), in particular annular around the axis of rotation (R), between the moving part (2), the static part (7), and said sealing system (9).

[0047] The radial positioning of the guide system (8) relative to the air sealing system (9) ensures good guidance of the CTIS at the level of the sealing system (9), which protects it from wear and ensures its performance.

[0048] The guide system (8) is therefore positioned radially with respect to the axis of rotation (R) of the moving part (2), external to the air sealing system (9). This particular arrangement allows for more space for the guide system (8). It is therefore possible to install a more robust guide system (8) to guarantee the service life of the CTIS. For example, it is possible to install higher-grade ball bearings, compared to bearings that would have been positioned internally with respect to the air sealing system (9).

[0049] Furthermore, placing the air sealing system (9) internally helps to limit its wear: since the radius of the air sealing system (9), measured from the axis of rotation (R), is reduced, then the circumferential speed at the point of contact of the sealing system (9) is reduced (recall the relationship v = w * r, with: - v is the circumferential speed; - co is the rotational speed; - r is the radius of the rotation).

[0050] Since the circumferential speed at the point of contact between the sealing system (9) and its antagonist is less, then the wear of the sealing system (9) is reduced.

[0051] In the illustrated example, the guide system (8) is in the form of a ball bearing, and the sealing system (9) comprises two annular seals, positioned side by side and spaced apart to define the chamber (10) between the seals, the moving part (2) and the static part (7).

[0052] The seals used can be of any suitable type, such as, for example, a radial friction lip seal positioned on the bottom side of the groove of the moving part (2), and a radial friction lip seal with a dust-proof lip positioned on the open side towards the outside of the groove.

[0053] Lip seals are preferred because they provide excellent sealing under dynamic conditions.

[0054] When the opposing surface of the seal lip is cylindrical (shaft or bore) rather than flat (counterbore), the resulting good seal is guaranteed by the machining precision implemented to achieve the desired dynamic balance on a vehicle wheel (coaxiality and cylindricity of the machined surfaces). There is therefore a synergy between the two results obtained.

[0055] According to the invention, the track widener (1) also includes at least one main fluidic conduit (11) formed in the static part (7) and opening: - at the level of a first end outside the track widener (1), for example on the hub side, and; - at the level of a second end in the chamber (10) between the moving part (2) and the static part (7).

[0056] The track widener (1) also includes at least one secondary fluidic conduit (12), having a minimum cross-section greater than 5mm 2 , provided in the movable part (2) and opening out: - at the level of a first end in chamber (10) and; - at a second end outside the track widener (1).

[0057] In this way, the first end of the main fluidic conduit (11) allows for the positioning of a supply valve, not shown, connected to the vehicle's compressed air supply circuit, and the second end of the secondary fluidic conduit (12), which rotates with the wheel, can be connected to a fluidic cavity defined between the rim and the tire. Preferably, the static portion (7) comprises only one main fluidic conduit (11), thus requiring only one connection between the wheel spacer (1) and the vehicle's compressed air supply circuit.

[0058] The air injected by the vehicle's compressed air supply circuit from the first end of the main fluidic conduit (11) of the static part (7) thus enters the chamber (10) and flows through the secondary fluidic conduit (12) of the moving part (2) to inflate or control the deflation of the tire.

[0059] The wheel spacer (1) according to the invention thus allows the installation and operation of a tire inflation system, interoperable on any type of vehicle, and in a reliable manner.

[0060] The wheel spacer (1) is positioned inside the wheel and is therefore protected from external damage, and does not detract from the overall aesthetics of the vehicle.

[0061] Moreover, the dynamic balance is optimal since the track widener (1) is positioned between two rotating components (3, 4) of the vehicle sharing the same axis of rotation (R).

[0062] Preferably, the moving part (2) includes at least two secondary fluidic conduits (12), regularly distributed angularly around the axis of rotation (R) to improve mass distribution and optimize the balancing of the rotating moving part (2). Also for this purpose, the secondary fluidic conduit(s) (12) of the moving part (2) open outside the enlarger at the axis of rotation (R) of the moving part (2), particularly in the cylindrical bearing area.

[0063] The invention makes it possible to set up and operate a CTIS, without requiring major modification of the components constituting the vehicle.

[0064] Even though in practice we seek to minimize the radial dimension of the wheel spacer (1) to limit friction and wear, the moving part (2) could have a radial dimension sufficient to extend radially beyond the hub so that the air sealing system (9) positioned between the moving part (2) and the static part (7) can be accessed without dismantling the assembly.

[0065] Preferably, the minimum cross-section of the main fluidic conduit when there is only one, or the sum of the minimum cross-sections of the main fluidic conduits (11) when there are several, is between 10 and 200 mm 2 , preferably between 20 and 150 mm 2 , and very preferably between 25 and 90 mm 2 . And, the minimum cross-section of the secondary fluidic conduit when there is only one, or the sum of the minimum cross-sections of the secondary fluidic conduits (12) when there are several, is equal to the minimum cross-section of the single main fluidic conduit (11) or to the sum of the minimum cross-sections of the main fluidic conduits (11).

[0066] To improve the vehicle's mechanical endurance and minimize the structural modifications required, the smallest axial dimension of the moving part (2), between a bearing surface of the first component (3) and a bearing surface of the second component (4), is less than 120 mm, preferably less than 60 mm, and most preferably less than 30 mm. The smaller this dimension, the better the vehicle's mechanical endurance.

[0067] From the above, the invention does indeed provide additional equipment on the vehicle, namely a wheel spacer, allowing the installation and operation of a tire inflation / deflation system, interoperable on any type of vehicle and resolving the reliability and aesthetic problems caused by direct adaptation to the wheel.

Claims

Demands

1. Wheel spacer (1) comprising: - a movable part (2), suitable for being fixed between a first component (3) and at least one second component (4) which are movable and rotate about an axis of rotation (R) of a vehicle assembly, the movable part (2) having an axis of rotation (R) intended to be coaxial with the axis of rotation (R) of the assembly, - a static part (7) capable of being linked to at least one fixed element of the vehicle, - a guidance system (8) for the rotational movement between the moving part (2) and the static part (7), characterized in that it comprises: - an airtight system (9) defining a chamber (10) between the moving part (2) and the static part (7), - at least one main fluidic conduit (11) provided in the static part (7) and opening, on the one hand, into the chamber (10) and, on the other hand, to the outside of the track widener (1), - at least one secondary fluidic conduit (12) provided in the moving part (2) and opening, on the one hand, into the chamber (10) and, on the other hand, to the outside of the track widener (1).

2. A track widener (1) according to claim 1 in which the guide system (8) is positioned radially to the axis of rotation (R) of the moving part (2), relative to the sealing system (9).

3. A track widener (1) according to any one of claims 1 to 2 in which the guiding system (8) is included in a group comprising: a ball bearing with one or more rows of balls, a needle bearing, a roller bearing, a self-lubricating bearing, a bushing.

4. Wheel spacer (1) according to any one of claims 1 to 3 in which the sealing system (9) is included in a group comprising: lip seals, V-shaped seals, O-rings, four-lobe seals, cassette seals.

5. A wheel spacer (1) according to any one of claims 1 to 4, wherein the minimum cross-sectional area of ​​the main fluidic conduit (11), when there is only one, or the sum of the minimum cross-sectional areas of the main fluidic conduits (11) is between 10 and 200 mm 2 , preferably between 20 and 150 mm 2 , most preferably between 25 and 90 mm 2 .

6. A track widener (1) according to claim 5 in which the static part (7) of the widener comprises a single main fluidic conduit (11).

7. A track widener (1) according to any one of claims 1 to 6 wherein the minimum cross-section of the secondary fluidic conduit (12), when there is only one, or the sum of the minimum cross-sections of the secondary fluidic conduits (12), is equal to the minimum cross-section of a single main fluidic conduit (11), or to the sum of the minimum cross-sections of the main fluidic conduits (11).

8. A track widener (1) according to claim 7 in which the movable part (2) comprises at least two secondary fluidic conduits, regularly distributed angularly around the axis of rotation (R).

9. A track widener (1) according to any one of claims 1 to 8 wherein a minimum cross-section of each secondary fluidic conduit (12) is greater than 5 mm 2 .

10. A track widener (1) according to any one of the preceding claims in which the secondary fluidic conduit (12) opens outside the widener at the axis of rotation (R) of the moving part (2).

11. Wheel spacer (1) according to any one of the preceding claims wherein, a smaller axial dimension of the movable part (2) between a first bearing face of the first component (3) and a second bearing face of at least one second component (4), is less than 120 mm, preferably 60 mm, most preferably 30 mm.

12. Vehicle comprising a wheel spacer (1) according to any one of the preceding claims mounted between a first component (3) and a second component (4) movable in rotation about an axis of rotation (R) of a mounted assembly of the vehicle, selected from a group comprising: a wheel, a brake disc, an axle, a hub, a spindle, bearings, a second wheel spacer.

13. Method of fixing a wheel spacer (1) according to any one of claims 1 to 11, between a first component (3) and at least one second component (4), movable in rotation about an axis of rotation (R) of a vehicle assembly in which, the fixing of the movable part (2) to the second component (4) is carried out using a fixing system initially present on the vehicle and previously intended to fix the assembly, the assembly being fixed securely to the movable part (2) in rotation of the spacer by a similar fixing system.

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