VEHICLE COMPRISING AN INDEPENDENTLY AIR SUSPENDED AXLE ASSEMBLY, AND AXLE ASSEMBLY

Abstract: Vehicle comprising a chassis and at least one independ­ ently air suspended axle assembly (5, 6) connected to the chassis, the axle assembly (5, 6) comprising a frame having at least one transverse beam (15) connected to the vehicle chassis and two longitudinal supporting arms (16) each piv­ otally connected to the transverse beam (15) by supporting arm bearings (26) extending to the rear thereof, bearing a wheel and being supported by an air spring (17). The trans­ verse beam (15) and the supporting arm bearings (26) extend sideways to a point in front of the wheels (20).

Description: Vehicle comprising an independently air suspended axle assembly, and axle assembly. The present invention relates to a vehicle comprising a chassis and at least one independently air suspended axle assembly connected to the chassis, the axle assembly comprising a frame having at least one transverse beam connected to the vehicle chassis and two longitudinal supporting arms, each pivotally connected to the transverse beam by supporting arm bearings, extending to the rear thereof, bearing a wheel and being supported by an air spring. An axle assembly for such a vehicle is known under the trade name INDAIR. Because of the high loads affecting such an axle assembly, the transverse beam has a heavy and bulky form for proper transmitting to the chassis the forces acting upon the wheels. Since the width of the transverse beam, and therefore the distance between the extreme points of the supporting arm bearings, correspond roughly with the distance of the chassis beams of the vehicle, a short path of force is obtained. This known axle assembly can be used instead of the more general and previously known rigid axle construction. The invention has for its object to provide a vehicle of the kind set forth above which, apart from the advantageous driving characteristics resulting from the independently air sprung wheel suspension, also offers advantages from the constructional viewpoint. This is achieved by a vehicle according to the invention in that the transverse beam and the supporting arm bearings extend sideways to a point in front of the wheels. Al though as a result the path of force from the supporting arm bearings to the place of attachment of the axle assembly with the chassis is enlarged, an unexpectedly advantageous load distribution in the axle assembly nevertheless results, bringing about a greater constructional freedom in the design of the remaining part of the vehicle. In particular, the space between the wheels can be utilised, which, especially for bulk transport wagons, is rather advantageous for attaining a low centre of gravity and a reduced construction length for a determined capacity. According to a further advantageous aspect of the invention the supporting arms, in top view, are T-shaped, with the supporting arm bearings on the transverse beam. In the supporting arm itself short paths of force occur, while moreover the load of the supporting arm bearings is advantageous. In a further development of the vehicle according to the invention a part of each supporting arm extending in longitudinal direction is formed by a straight box girder, on an upper face of which a support bearing the wheel is arranged. On the supporting arm, between the wheel support and the supporting aria bearing, the brake control air cylinder and the height regulation valve for the air suspension can be mounted in an advantageous manner. The space between the wheels, therefore, remains entirely free, so that if the vehicle is for example a tank wagon, a part of its tank can extend into the axle assembly. A particularly advantageous embodiment of the vehicle according to the invention has the characteristic that the supporting ans bearings are arranged on the rear side of the transverse bean and the transverse beam is attached by supports to a connecting part of the wheel assembly coupled with the vehicle chassis. As a result a "tunnel" occurs which is free over a height area between the wheels in the longitudinal direction of the vehicle, in which an element of the vehicle, such as for example a bulk conduit, can extend in a particularly suitable manner. In relation to vehicle con structions known up until now which have an underlying bulk conduit, it is possible to achieve a very considerable lower ing of the bulk conduit level with the advantageous consequence of a lower construction of the reservoirs and therefore a lower location of the centra of gravity, or a shorter length. According to a further advantageous aspect of the invention the axle assembly is a bogie which is rotatable around a vertical axis by steering means. The free space in the axle assembly can have a generally equal length and width, so that the axle assembly can be made, in a suitable way, as a bogie, without limitations to the constructional freedom for the vehicle superstructure. A bulk conduit or the like can also extend through the bogie. As a result of the large free space, the pivot angle of the bogie is not limited by the bulk conduit. The invention also relates to and provides an axle assembly apparently intended for a vehicle according to the invention as previously described. The axle assembly can be manufactured in the known manner as a substantially separate construction part. The invention will be described more fully in the following with reference to the examples shown in the Figures. Fig. 1 shows a schematic side view of a vehicle in accordance with the invention. Fig. 2 shows a partially broken away perspective view of the axle assembly of the vehicle in Fig. 1. Fig. 3 is a simplified front view of the axle assembly in Fig. 2 according to arrow III therein. Fig. 4 shows a schematic side view of another enbodiment of the vehicle according to the invention. Fig. 5 shows a partial front view of the axle assembly of the vehicle in Fig. 4. Fig. 6 shows a section taken according to line VI-VI in Fig. 5. Fig. 7 shows a front view corresponding to Fig. 6, of another embodiment of an axle assembly according to the invention. Fig. 8 shows a section according to line Vili-Vill in Fig. 7. The vehicle 1 according to the invention comprises a tractor 2 and a bulk semi-trailer 3 drawn by it. The tractor 2 and semi-trailer 3 are pivotally coupled by a coupling 11. The se,ai-trailer 3 is supported at the rear by two axle assemblies 5, 6. The rear axle assembly 5 is coupled pivotally on a vertical axis with the semi-trailer 3, and the axle assembly 6 has a fixed connection with the trailer 3. The latter has a self-supporting construction, so that the chassis is integrated in it. The bogie 5 is connected with a feed funnel 4 and is pivotable around the axis of symmetry of this feed funnel 4. The frame of the fixed axle assembly 6 is weade such that it extends around an intermediate feed funnel 13, and is additionally supported by an auxiliary construction 14. The rotatable axle assembly 5 is provided with steering arms 7 projecting sideways to a point above the wheels, which arias are connected by means of steering rods extending in longitudinal direction to a steering arm 9 which is mounted under the trailer at the forward end. The steering arm 9 has an engaging arm 10 which engages a fixed point of the tractor 2 near the coupling II. This construction achieves that, when the tractor 2 is at an angle in relation to the trailer 3, in driving through a curve, the steered axle assembly 5 is pivoted such that its position is adjusted to the curve. The steering construction of the bogie 5 is known as such and does not form subject of the present application. As is shown in Fig. 2, the axle assembly 5, which in principle corresponds to the assembly 6, comprises a transverse beam 15 and two longitudinal supporting arms 16, each connected to the transverse beam 15 by supporting arm bearings 26, extending to the rear of the beam, bearing a wheel 20 and being supported by an air spring 17. According to the invention, the transverse beam 15 and the supporting arm bearings 26 extend sideways to a point in front of the wheels 20. This is rather clearly seen in Fig. 3. In the particular embodiment of the axle assembly 5 according to the invention as shown, the supporting arm bear ings 26 are arranged on the rear side of the transverse beam 15, and the latter is attached by supports 35 to a connecting part of the axle assembly, in the form of a subframe 36, connected to the vehicle chassis. As can be seen in Fig. 3, this results in a free spece 38 between the wheels of a very considerable height, so that the bulk conduit 12 of the bulk trailer 3 can extend unobstructed through this free space 38 at the very low height corresponding to the level of the axis of rotation of the wheels. The axle assembly 5 is very suitable as bogie because of the outward location of the supporting arm bearings 26, while a bulk conduit 12 can still extend through the free space in the axle assembly. The attainable pivot angle is indicated by arrow 22. The supporting arms 16 are in top view T-shaped. The supporting arm bearing is located on the cross piece. The part of the supporting arms 16 which extends in longitudinal direction is formed by a straight box-girder 25. On the upper face of the box-girder 25 a wheel axle support 18 is mounted, bearing the wheel axle 19, having attached to it by means of bearings, a wheel 20. As a result of this construction, there is sufficient space available between the supporting arm 16 and the subframe 36 for mounting the brake air cylinder 30 on the supporting arm 16. This brake air cylinder operates the brake arm 31 of the wheel brake in known manner. Moreover, there is space available for the height control valve 32 of the air suspension. It can also be clearly seen in Fig. 2 that, as a result of this measure, the free space between the wheels is indeed entirely unobstructed. A shock absorber 21 is in each case attached between the supporting are 16 ;inC the subframe 36. In the embodiment shown, this shock absorber is mounted near the rear end of the supporting arm 16. Normally speaking, the absorber 21 will not form any obstruction in this position. Nevertheless, it is of course possible to mount the absorber 21 in another position. The supporting arm bearings 26 comprise a bearing axle 27 which is mounted by nuts in supports that project backwards of the transverse beam 15. In the cross tube of the supporting arm 16 bearings which are supported by the axle 27 are fitted in the known manner. As previously stated, the bogie 6 is made identical to the bogie 5, the bogie 6, however, being directly connected to the chassis of the semi-trailer 3, whereas the bogie is connected to it by means of the rotatable crown 37. In Figs. 2 and 3 the steering arms 7 of the bogie are no longer shown. Fig. 3 indicates that the wheel supporting arms 16 are mounted to the transverse beam 15 at a small angle 39, so that the wheels 20 obtain a positive wheel camber. The ends 40 of the transverse beam 15 of the axle assembly 5 extend sideways to a point past the centre of the wheels 20, as Fig. 3 also shows. The vehicle 45 of Fig. 4 comprises a tractor 46 and a semi-trailer 47. The trailer 47 has a chassis 48 at the rear resting on two axle assemblies 49 and 50. The axle assembly 50 is controlled by the steering apparatus 51 in a manner corresponding to the description for the vehicle in Fig. 1. The axle assembly 50, partially shown in front view in Fig. 5, comprises a transverse beam 52 which extends sideways to a point in front of the wheels 56. Since the vehicle 45 has no bulk conduit or the like, the free space between the wheels 56 at the front does not need to be accessible, so that, for constructional reasons, the transverse beam 52 is attached directly to the frame 53. The supporting arm 55 is pivotally mounted at the underside of the transverse beam 52 by mea¯nt of the supporting arm bearing 54. Witll reference to Figs. 5 and 6 it can be clearly seen that the load on the supporting arm bearing 54 is rather advantageous. The line between the furthest projecting end 57 of the supporting arm bearing 54 and the air spring 58, seen in vertical direction, extends closely along or through the contact face of the wheel 56 with the ground. The static load on the bearing 54 close to the end 57, therefore, forms only a limited part of the total wheel load. The static load on the bearing 54 near the end 59 is moreover very salt. It is clear to see that the dynamic loads are limited in a corresponding manner. The wheel assembly 60 of Figs. 7 and 8 likewise comprises a transverse beam 61, on the underside of which the supporting arms 67 are pivotally mounted by means of the supporting arm bearings 64. Using supports 63 the transverse beam 61 is coupled with the subframe 66, which in turn is again connected to the vehicle. The air spring 65 supports on the rear end of the supporting arm 67. As a comparison of Fig. 7 with Fig. 3 shows, the supporting arm bearing 64 of the bogie 60 is mounted on the underside of the transverse beam 61, while the supporting arin bearing of the bogie 5 is situated on the rear side. The axle assembly 60 can be used in those cases where the free access to the space between the wheels 62 in the axle assembly 60 only needs to be of limited height. In that case, the supports 63 can be made lighter.

Claims: Claims 1. Vehicle comprising a chassis and at least one independently air suspended axle assembly connected to the chassis, the axle assembly comprising a frame having at least one transverse beam connected to the vehicle chassis and two longitudinal supporting arms, each pivotally connected to the transverse beam by supporting arm bearings, extending to the rear thereof, bearing a wheel and being supported by an air spring, c h a r a c t e r i z e d in that the transverse beam and the supporting arm bearings extend sideways to a point in front of the wheels. 2. Vehicle as claimed in Claim 1, c h a r a c t e r i z e d in that the supporting arms in top view are T-shaped with the supporting arm bearings on the cross piece. 3. Vehicle as claimed in Claim I or 2, c h a r a c t e r i z e d in that a part of each supporting arm extending in longitudinat direction is formed by a straight box girder, on an upper face of which a wheel bearing support is provided. 4. Vehicle as claimed in any of the preceding Claims, c h a r a c t e r i z e d in that the supporting arm bearings are mounted on the rear side of the transverse beam and that the latter is attached by supports to a connecting part of the wheel assembly coupled with the vehicle chassis. 5. Vehicle as claimed in any of the preceding Claims, c h a r a c t e r i z e d in that the axle assembly is a bogie rotatable around a vertical axis by steering means. 6. Axle assembly apparently intended for a vehicle as claimed in anyone of the preceding Claims.

Inventors: WELLINK, THEODORUS ANTONIUS
Applicants: WELGRO B.V.
Application year: 1985
Main classification: B60G11
IPC codes: B62D13, B60G11, B60G3