SWIVEL CONNECTION FOR CONTROLLING OF THE AIR PRESSURE IN A TYRE FOR A VEHICLE

Abstract: Swivel connection for the regulation of air pressure in a tyre (2) assembled on a rim (1) of a vehicle wheel in traffic, comprising a first ring-shaped member (4.1) that is fixedly connected with the rim (1) and that rotates with the wheel of the vehicle when rotating around its hub (3), and a second ring-shaped member (4.4) that is not rotary arranged in relation to the hub (3) and that interacts with the first ring-shaped member (4.1). A ring-shaped duct (4.3) is formed between the first and the second ring-shaped member (4.1, 4.4) which is connected with partly the inner air space in the tyre (2), partly an air-pressure unit for regulation of the air-pressure in the tyre (2). The second ring-shaped member (4.4) is connected with the first ring-shaped member (4.1) via a bearing (4.9) and is prevented to rotate around the hub (3) by means of an in relation to the hub fixedly aranged holder (5).

Description: SWIVEL CONNECTION FOR CONTROLLING OF THE AIR PRESSURE IN A TYRE FOR A VEHICLE. TECHNICAL FIELD The present invention relates to a swivel connection for the regulation of air pressure in a tyre assembled on a rim of a vehicle wheel in traffic comprising a first ring-shaped member that is fixedly connected with the rim and rotates with the wheel of the vehicle when rotating around its hub, and a second ring- shaped member that is not rotary arranged in relation to the hub and that interacts with the first ring-shaped member. A ring-shaped duct is formed between the first and the second ring-shaped member, which is connected with partly the inner air-space in the tyre, partly an air-pressure unit for regulation of the air-pressure in the tyre both when the vehicle is moving and when its not moving. PRIOR ART Right tyre pressure is and has been important for road holding abilities and availability of vehicles of many different types. To change the tyre pressure in the conventional way, that is to increase the air pressure by means of a stationary air compressor or to deflate the tyre manually is not a practical way when the need for pressure regulation changes at short intervals. Several solutions to solve this problem therefor have been presented. Here is assumed that the wheel is rotary on a hub showing bearings and possibly encloses a driving axle for the wheel concerned. Those solutions have in common that a swivel connection is arranged in connection to the hub, compressed air being fed into the tyre or the tyre being deflated via a duct in the hub that is in connection with a ring-shaped duct extending between the hub and the rim that carries the tyre. Hub and rim therefor have to be provided with this swivel connection already when constructing the wheel system. Examples of such constructions are known among others from the American patent applications US 3 705 614 and US 5 203 391. A solution that differs somewhat from those is known from the patent application US 2 017 158 where the wheel is fixedly assembled on an axle that in its turn is — rotary in a bearing and where the swivel connection is arranged between the hub and a brake drum belonging to the wheel. None of the known solutions admits the swivel connection to be assembled afterwards on a vehicle wheel and nor do they admit that the movement of the wheel differs materially from its ideal travel. DESCRIPTION OF THE INVENTION The object of the present invention is to achieve a swivel device to be assembled afterwards on different types of vehicle wheels and which admits a regulation of the tyre pressure even when the vehicle is moving and that is insensitive to deviations from the ideal rotation of the wheel, that is, insensitive to a possible eccentricity in the movement of the rim or deviation from the ideal plane of rotation transversely to the direction of axis of the hub. The object is achieved with a swivel device according to the preamble where the second ring-shaped member is connected with the first ring-shaped member via a bearing and is prevented from rotation around the hub by means of an in relation to the hub fixedly arranged holder. Preferably the holder is elastic connected with the second ring-shaped member in order to be able to take up the mentioned deviations in the rotation if the wheel. The holder is with advantage assembled on the hub by means of a clamping device that is adaptable for different types of hubs. The first ring-shaped member may be rotary in relation to the second ring-shaped member, for instance a ball bearing application comprising balls that are held apart by distance members. The two interacting rings in this embodiment are held together by means of a clamp ring that also is part of the bearing race in the ball bearing application. Two on each side of the fixed ring and in radial direction arranged sealing joints prevent dirt and water to penetrate in to the ball bearing application. In a preferred embodiment the first ring-shaped, member is a rotary ring showing a U-shaped cross section that forms a ring-shaped duct, which is open in a direction towards the vehicle chassis and that is connected with the tyre via a conduit, and the second ring-shaped member is a fixed ring arranged in the duct and sealing it. A conduit for compressed air feed in order to raise the tyre pressure or for deflation in order to lower the tyre pressure is connected with a case that is arranged on the second ring-shaped member and is connected with an air duct that extends through this member to the ring-shaped duct. The feed duct ends in a ring-shaped slot in the second ring-shaped member which carries a ring-shaped sealing that extends into the ring- shaped duct and which is provided with along the circumference equally spread holes through which air can pass to the respective from the ring-shaped duct. It lies within the scope of the invention to vary the embodiment of the two ring-shaped members within broad limits. Thus may for instance the ring-shaped duct be formed in the second, fixed ring-shaped member instead of in the first, rotary member. The holder that prevents the rotation of the second, fixed member may be placed on other parts of the vehicle chassis than the hub on condition that such a solution is to prefer by constructional reasons. Further features and characteristics concerning the present invention are evident from the description to the drawings below and from the claims. DESCRIPTION TO THE DRAWINGS The invention is described below as an example of an embodiment in connection with the enclosed drawings . Figure 1 shows a wheel of a working machine assembled on a hub seen from the chassis and outwards to the hub and partly cut and provided with a ring-shaped swivel connection according to the invention. Figure 2 shows the swivel connection separately , and seen in the same direction as in figure 1. Figure 3 shows a cross section through the swivel connection along line I-I in figure 2. The wheel shown in figure 1 comprises a hub 1 that carries a tyre 2 of rubber and that is assembled via conventional, not shown bearings, on a hub 3 that in its turn is fixedly connected with the vehicle chassis. A swivel connection 4 according to the invention is assembled on the inside of the rim 1 and is connected with partly the interior air space in the tyre 2, partly a compressed air unit comprising among other things a compressor with a pressure vessel belonging to it and electrical operated valves for the regulation of the tyre pressure. The compressed air unit shows in the main known techniques and is not shown in the figures. The swivel connection 4, shown in detail in figures 2 and 3, comprises a ring 4.1, rotary with the wheel, and is fixed to the rim 2 with screws via braces 4.2. The rotary ring 4.1 shows an U-shaped cross section that constitutes a ring-shaped duct 4.3 that is open in a direction towards the vehicle chassis and that is connected with the tyre 2 via a conduit, not shown in the figures. A fixed ring 4.4 is arranged in the duct 4.3 in the rotary ring 4.1 and is connected to a holder 5, fixedly assembled on the hub 3, whereby it is prevented to rotate with the rotary ring 4.1 when the ring rotates with the wheel concerned. The holder 5 is in two pieces and gets clamped to the hub 3 by means of clamping screws, not shown in the figures. The holder 5 carries a radial protruding arm 5.1 that in its turn is connected with one on the fixed ring 4.4 arranged connecting case 6 via a slewing bracket 5.2 showing rubber bushings 5.3 that are able to take up deviations in movements of the rotary ring 4.1 as for instance eccentric movements around the hub 3 or deviation from the ideal plane of rotation perpendicular to the hub 3. A conduit 6.1 for compressed air feed in order __ to raise the air pressure in tyre 2 or for deflation in order to lower the air pressure in tyre 2 is connected with a case 6 and is connected with an air duct 4.5 that extends through the fixed ring 4.4 to the ring-shaped duct 4.3 in the rotary ring 4.1. The feed duct 4.5 ends in a ring-shaped slot 4.6 in the fixed ring 4.4 that carries a ring-shaped sealing 4.8 that extends into the ring-shaped duct 4.3 in the rotary ring 4.1 and which is provided with a number of along the circumference equally spread holes through which air can pass to the respective from the ring-shaped duct 4.3. The rotary ring 4.1 rotates in relation to the fixed ring 4.4 on the ball bearing application 4.9 and comprises balls that are kept apart by distance members for instance of plastics, not shown in the figures. The two interacting rings 4.1, 4.4, are held together by means of a clamp ring 4.10 that also is part of the bearing race in the ball bearing application 4.9. Two sealing joints 4.11 are arranged on each side of the fixed ring and in radial direction to prevent dirt and water to penetrate into the ball bearing application. Figure 3 also shows an inlet plug 7 for a conduit, not shown in the figures that is connected with the air space of the tyre 2.

Claims: CLAIMS 1. Swivel connection for the regulation of air pressure in a tyre (2) assembled on a rim (1) of a vehicle wheel in traffic comprising a first ring-shaped member (4.1) that is fixedly connected with the rim (1) __ and rotates with the wheel of the vehicle when rotating around its hub (3), and a second ring-shaped member (4.4) that is not rotary arranged in relation to the hub (3) and that interacts with the first ring-shaped member (4.1), a ring-shaped duct (4.3) being formed between the first and the second ring-shaped member (4.1, 4.4) which is connected with partly the inner air-space in the tyre (2), partly an air-pressure unit for regulation of the air-pressure in the tyre (2), characterised in that the second ring-shaped member (4.4) is connected with the first ring-shaped member (4.1) via a ball bearing application (4.9) and is prevented to rotate around the hub (3) by means of one in relation the hub fixedly arranged holder (5). 2. Swivel connection according to claim 1 or 2, characterised in that the holder (5) is elastic connected with the second ring-shaped member (4.4). 3. Swivel connection according to claim 1 or 2, characterised in that the holder (5) is assembled on the hub (3) . 4. Swivel connection according to any of claims 1-3, characterised in that the first ring-shaped member is a rotary ring (4.1) showing an U-shaped cross section that forms a ring-shaped duct (4.3) that is open in a direction towards the vehicle chassis and that is connected with the tyre (2) via a conduit, and that the second ring-shaped member is a fixed ring (4.4) that is arranged in the duct (4.3) and seals it. 5. Swivel connection according to any of claims 1-4, characterised in that a conduit (6.1) that is connected with a compressed air unit for compressed air feed in order to raise the air pressure in the tyre (2) or for deflation in order to lower the air pressure in the tyre (2) is connected with a case (6) that is arranged on the second ring-shaped member (4.4) and is connected with an air duct (4.5) that extends through this member (4.4) to the ring-shaped duct (4.3). __ 6. Swivel connection according to claim 5, characterised in that the feed duct (4.5) ends in a ring- shaped slot (4.6) in the second ring-shaped member (4.4) which carries a ring-shaped sealing (4.8) extending into the ring-shaped duct (4.3) and which is provided with a number of along the circumference equally spread holes through which air can pass to the respective from the ring-shaped duct (4.3). 7. Swivel connection according to any of claims 1-6, characterised in that the first ring-shaped member (4.1) is rotary in relation to the second ring-shaped member (4.4) on a ball bearing application (4.9) comprising balls that are held apart by distance members. 8. Swivel connection according to claim 7, characterised in that the two interacting ring-shaped members (4.1, 4.4) are held together by means of a clamp ring (4.10) that also is part of the bearing race in the ball bearing application (4.9). 9. Swivel connection according to claim 7 or 8, characterised in that two sealing joints (4.11) are arranged in radial direction on each side of the second ring-shaped member (4.4) and prevent dirt and water to penetrate in to the ball bearing application (4.9).

Inventors: ARVIDSSON SOEREN, LINDELL ANDERS, ARVIDSSON, SOEREN, LINDELL, ANDERS
Applicants: ARVIDSSON SOEREN, INNOVATIONSSUPPORT AB, LINDELL ANDERS, ARVIDSSON, SOEREN, LINDELL, ANDERS
Application year: 1999
Main classification: B60C23
IPC codes: B60C23