Abstract:
An axle-and-hub assembly for a trailer which includes an axle with opposing ends, first and second connecting devices respectively positioned at the opposing ends of the axle, and first and second hub arrangements which are removably secured to the first and second connecting devices.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates to an axle-and-hub assembly for a trailer. 
         [0002]    An axle-and-hub assembly couples a trailer&#39;s wheels to a body of the trailer and allows the wheels to rotate about an axis which is aligned with the axle which, in turn, remains stationary. 
         [0003]    The axle-and-hub assembly bears the entire weight of the trailer and its payload and, additionally, is exposed to acceleration and braking forces. In order to withstand these forces the axle-and-hub assembly typically includes an integral hub which is strong and durable. A disadvantage of this type of construction though is that the entire assembly must be discarded if the hub-end of the assembly becomes damaged. Not only is this expensive but the removal of the damaged axle-and-hub assembly from the body of a trailer is a laborious task which results in considerable downtime. 
         [0004]    An object of the present invention is to provide an axle-and-hub assembly which, at least partly, addresses the aforementioned problems. 
       SUMMARY OF INVENTION 
       [0005]    The invention provides an axle-and-hub assembly, for a trailer, which includes an axle with opposing ends, first and second connecting devices respectively positioned at the opposing ends of the axle, and first and second hub arrangements which are respectively removably secured to the first and second connecting devices. 
         [0006]    Each connecting device may be in any suitable form and preferably is a steel flange. Each flange may be welded, and interference fitted, to a respective end of the axle. 
         [0007]    Each flange may include a plurality of holes which are regularly spaced from one another on a circle centred on an axis of the axle. 
         [0008]    Each hub arrangement may include a plate which can be directly connected to a respective flange. The plate and the flange may include complementary interengageable formations. For example the flange may include an axially extending boss and the plate may include an axially extending recess which is complementary in shape and size to the boss. The plate on the hub arrangement may otherwise be substantially identical in shape and size to the flange with which it is engaged. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The invention is further described by way of example with reference to the accompanying drawings in which: 
           [0010]      FIG. 1  is a perspective view of a trailer axle-and-hub assembly according to the invention, 
           [0011]      FIG. 2  shows part of one end of the axle-and-hub assembly of  FIG. 1  in an exploded configuration, 
           [0012]      FIG. 3  shows a connecting flange used in the axle-and-hub assembly, and 
           [0013]      FIG. 4  is a side view of components at one end of the axle-and-hub assembly in  FIG. 1  in an exploded configuration. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
       [0014]      FIG. 1  of the accompanying drawings illustrates an axle-and-hub assembly  10  which includes an axle  12  with opposed ends  14  and  16  respectively and hub arrangements  18  and  20  engaged with the respective axle ends  14  and  16 . 
         [0015]    The axle  12 , which in this example is square in cross section, includes first and second connecting flanges  22  and  24  respectively which are interference fitted, and welded, to the axle  12 . Each flange is drilled with a number of holes  26  which are regularly spaced from each other and which are positioned on a circle centred on an axis  28  which is aligned with the axle. A knurled stud  30  is press-fitted to each respective hole  26 . 
         [0016]    The hub arrangements  18  and  20  are identical. For this reason only the construction of the hub arrangement  18  is described. The hub arrangement  18  includes a hub  32  which is mounted to a stub axle  34 . A steel plate  36  is fixed to what, in use, is an inner end of the stub axle  34 . The steel plate  36  is for all practical purposes the same as the flange  22  and has holes  38  which are brought into register with respective holes  26 . These holes are however clearance holes and enable shanks of the studs  30  to pass through the holes. 
         [0017]    As is clearly shown in  FIGS. 2 and 4  the flange  22  has an axially extending circular boss  40  at an inner perimeter. The plate  36  has an axially extending recess  42 , which is complementary in shape and size to the boss, on a surface  44  which opposes the flange  22 . The recess  42  is designed to receive the boss  40  in a close fitting and aligned manner which ensures that the hub arrangement is correctly positioned and axially aligned with the axle. Studs  30  are then used to fix the flange to the plate in a secure manner. 
         [0018]    The second end  16  of the axle is arranged and constructed in a similar manner. 
         [0019]      FIGS. 2 and 3  in particular show that the flange  22  has a recess  50  which is in register with a similarly shaped recess  52  in the connecting plate  36 . This allows for the passage of an S-cam rod  54  which is connected between the hub  32  and a shock absorbing arrangement  56 , of conventional construction, which is centrally located on the axle  12 . 
         [0020]    A principal benefit of the invention is that a damaged hub arrangement ( 18  or  20 ), can be replaced without removing the axle. This capability reduces the cost of repair and maintenance, and downtime. 
         [0021]    The strength of the assembly is not compromised, an aspect which was verified by subjecting an axle, with a 12 ton load rating, to a test to evaluate, inter alia, the integrity of the flanged connections ( 22 , 36 ) under application of a quasi-static, vertical load representative of actual service conditions. Based on the rated static load of 12 ton and a vertical acceleration of  3   g  a compressive load, applied to the axle assembly, was increased to 36 ton. After the load was released an inspection of the assembly showed that there was no damage nor permanent deformation. The load was increased further and it was only at a loading of 62 ton that the assembly suffered damage. 
         [0022]    The principles of the invention are applicable with equal effect to axles which are square or circular in cross section. The hub arrangement could be braked or unbraked.