Patent Application
20090134593
The present invention relates to a mounting system for securing an axle casing to a frame of a vehicle by a V-stay connecting the axle casing to right frame portions and left frame portions of the frame, where said V-stay includes two arms which are joined together in a mounting bushing and a fastening member extending through said bushing generally parallel to the axle casing, where said fastening member is provided with first and second mounting brackets at each protruding end and that said first and second brackets are secured to corresponding first and second bosses provided on the top of the axle casing by a first and second threading members, which are extending through mounting holes in the first and second brackets and in the first and second bosses, and where the first and second brackets and first and second bosses are provided with complementary contact surfaces.
A mounting system of such kind is known from U.S. patent application No. 2001/0009321 A1. This mounting structure for a suspension V-rod is used in a large-sized vehicle, such as a track or a bus to suspend the rear axle or axles. The suspension structure in vehicle includes amongst other elements a V-rod structure connecting the rear wheel axle and the frame for transferring acceleration and brake forces from the axle to the frame and for keeping the rear axle in its sideways position.
In the mounting system, the bolts fastening the traverse fastening bar to the bosses on the axel casing absorb the shearing forces and transfer these forces from the axle to the frame. In order to ensure this transfer in the mounting system, the bolts are fastened with a predetermined torque control so that sufficient frictional force and thereby a firm connection between the brackets and bosses is provided for absorbing the acceleration and brake forces. However, this results in a high pre-loaded stress on the fastening bolts. If the bolts in excessive loading conditions are also loaded with shearing stress when absorbing lateral forces acting generally parallel to the contact surfaces of the brackets and bosses, the bolts may damage or even break. This implicates a separation risk between the V-stay and the axle, if the bolts are loaded to an extent where there is a risk of breaking the bolts. To reduce this risk, the mounting structure must be frequently maintained.
It is desirable to provide a mounting structure of the initially mentioned kind, where the risk of separation is eliminated due to fracturing the bolts.
An aspect of the invention comprises a mounting system of the initially mentioned kind, wherein the bosses on the axle and the corresponding brackets on the fastening member are provided with mating contact surfaces that are tapered around the mounting holes.
By providing mating tapered contact surfaces on the boss and the bracket on each side of the V-stay bushing, the threading members, e.g. the bolts, relieved of shearing stress loads, as any lateral impact on the mounting system may be absorbed by the mating contact surfaces of the boss and bracket fastening on each side of the bushing of the V-stay. Besides absorbing impacts and relieving the stress on the threading members, the fastening member is easily mountable in the bosses on the axle casing by a mounting system according to the invention, since the tapered contact surfaces are self-centering and the two parts are thereby easily correctly positioned and secured by two threading members.
Preferably, the tapered surfaces are conically tapered. This shape is easy to manufacture and makes the two parts, i.e. a bracket and a boss, easy to align and thereby position correctly relatively to each other. Alternatively, the tapered surfaces could be spherical or any other geometric shape where the diameter is reduced in the direction of the threading member.
In an aspect of the invention, the tapered surfaces of the bosses are provided as recesses. This makes the mounting easy.
In an aspect of the invention, the mounting holes of the bosses are through holes and the threading members are bolts and nuts. Alternatively, the mounting holes of the bosses are provided with internal threading in which the threading members, in this embodiment bolt screws, are secured. According to the actual application, the type of threading member and adaptations to the axel bosses may be chosen.
In the following, the invention is described in more detail with reference to the accompanying drawings, in which:
As shown in
In
As shown in more detail in
In
The brackets 109, 110 of the fastening member 108 are provided with tapered contact surfaces 116, 115 and correspondingly shaped, tapered contact surfaces 117, 118 are provided on the bosses 111, 112. The bracket contact surfaces 115, 116 and the mating contact surfaces on the bosses 111, 112 are brought into contact with each other when the fastening member 108 is secured to the axle casing 1. The first bracket 109 is provided with a through-going hole 120 essentially perpendicular to the orientation of the fastening member 108. The corresponding first boss 111 is also provided with a blind hole 122, which is provided with an internal threading for receiving a first screw bolt 113. This design is mirrored on the second side of the bushing 107, where the second bracket 110 mates with the second boss 112 and are both provided with aligned holes 119, 121, where the boss hole 121 is a blind hole provided with an internal threading.
In the embodiment shown in
The invention is described above with reference to some preferred embodiments. However, it is realised that variations of the mounting system according to the invention may be made without departing from the scope of the accompanying claims.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/SE04/01751 | 11/26/2004 | WO | 00 | 5/25/2007 |
