Joining device for a vehicle's frame and a wheel axle

The present invention relates to a joining device for joining a frame of a vehicle and a wheel axle, which joining device comprises a V-shaped rod (hereinafter called a V-stay), as indicated in the introduction to claim 1. There are a number of solutions for joining a V-stay mounted on a vehicle and a wheel axle. Normally a bearing is mounted that provides flexibility in the joining device, generally in the form of a type of ball bearing. Examples of such joining devices are described, for example, in the applicant's own application PCT/NO98/00356 which describes the principle for mounting a V-stay's central bearing. In the applicant's own application PCT/NO2005/000069, a V-stay is described with a flange which has a slanting pin on which the central bearing is located.

A problem with bearings is that the bearing surfaces in the bearing become worn down with time and have to be regularly replaced. This problem applies especially to the type of ball bearing which only has one mounting point. This is because as they become worn, the bearing surfaces are no longer in close abutment with one another, thus causing slackness in the bearing. For the ball bearing, which has a one-sided mounting on a centre pin with a centre axis substantially perpendicular to a base plane for the vehicle, after the bearing has been used for some time there is a risk that the ball bearing will jump off and the connection between the vehicle and the wheel axle will be lost. Alternative solutions are known which attempt to prevent the ball bearings being loosened in this manner, an example being described in the applicant's own application PCT/NO04/00073. This solution provides partial protection, but in time this protective measure will also become worn. An object of the present invention is to provide a joining device for the frame of a vehicle and a wheel axle comprising a V-stay, which joining device has good freedom of movement, but also has built-in protection against unintentional release of the joining device.

It is an object to provide a joining device which offers a greater degree of protection against its unintentional release than previously known solutions. It is also an object that the joining device should have freedom of movement particularly in the longitudinal direction of the vehicle.

A further object is to provide a joining device which is simple both in installation, but also with regard to maintenance, and which can easily be monitored with regard to maintenance. It is also an object to provide a device where it can easily be ensured that the joining device has been provided with the correct tolerances.

These objects are achieved with the present invention as indicated in the following independent patent claims, where further embodiments of the invention will be apparent from the dependent patent claims.

The present invention relates to a joining device for joining a frame of a vehicle and a wheel axle, comprising a V-shaped stay (hereinafter called a V-stay) mounted between the vehicle's frame and the wheel suspension. This is, for example, a normal joining device for frames and wheel axles for larger vehicles, such as lorries. The V-stay is link-coupled to the frame and connected to the wheel suspension via a bearing. This bearing comprises an internal bearing element with an external partly spherical abutment surface and an external bearing element with an internal partly spherical abutment surface, corresponding to a ball bearing. This provides the necessary flexibility in the connection in order to absorb transverse heeling motion and spring travel in the vehicle's longitudinal direction as well as a good force transmission between V-stay and wheel axle. In a normal position of the vehicle, the bearing in the joining device according to the invention has a centre axis oriented substantially perpendicularly relative to a base on which the vehicle is located, a so-called vertically oriented ball bearing. The term "substantially perpendicularly relative to" should be understood to mean that the centre axis of the bearing may also be given a small angle relative to the perpendicular to the base, as described, for example, in the applicant's own patent application SE 0400455-2.

The internal bearing element of the bearing is mounted at one end of the centre axis - a so-called one-sided mounted bearing.

According to the present invention the internal bearing element comprises a stopper element. This stopper element cooperates with a locking portion of the external bearing element, preventing the external bearing element from being unintentionally released from the internal bearing element. In a plane substantially perpendicular to the centre axis, the stopper element forms an elongated cross section with a longitudinal direction of the cross section oriented in a direction substantially across the vehicle. This provides the greatest flexibility in the bearing. Such a design of the stopper element has little or no influence on the bearing's flexibility about an axis which is transverse relative to the vehicle, with the result that there is large spring travel in the longitudinal direction of the vehicle, and only a slight influence on the bearing's flexibility about a longitudinal axis relative to the vehicle, with the result of minimum influence on the heeling flexibility by the stopper element. Thus, even with slackness in the bearing, the stopper element will prevent the external bearing element from being released unintentionally from the internal bearing element, since the stopper element is larger than the locking portion and their interaction prevents release.

In an embodiment of the invention the stopper element is mounted at an end of the internal bearing element opposite a mounting end for the internal bearing element.

The size of this stopper element is greater than a diameter of the internal partly spherical surface of the external bearing element, in a plane substantially perpendicular to the centre axis, i.e. in a plane substantially parallel with a base for the vehicle. In this embodiment, a portion of the external bearing element by the internal partly spherical surface forms the locking portion of the external bearing element. The locking portion can therefore be composed of a portion of a bearing housing wherein a wear bearing element comprising the partly spherical surface is mounted near the spherical surface or of an end surface of such a wear bearing element. In a second embodiment of the invention the stopper element is mounted between the external partly spherical abutment surface and a mounting end of the internal bearing element. In the embodiment, the locking portion of the external bearing element is composed of a portion of a bearing housing that encircles the internal spherical surface, where the locking portion of the bearing housing has an internal diameter that is less than the length of the stopper element.

The length of the stopper element preferably refers to the longitudinal direction thereof in both these embodiments of the invention.

In a preferred embodiment a bearing housing of the external bearing element comprises a recess complementary to the stopper element, thereby achieving the necessary flexibility in the bearing. This can be implemented in a plurality of ways, such as, for example, by a cover secured to the external bearing element having a shape comprising a recess and/or a shape which, when it is secured to the external bearing element, forms a space round the stopper element; an alternative to a cover is a completely surrounding external bearing housing with a recess or bore to provide space for the stopper element; or the external bearing element comprises an open bearing housing which is not extended past the external bearing element's bearing surface.

In a preferred embodiment of the invention the internal bearing element is mounted on the wheel suspension and the external bearing element is mounted on the V-stay and comprises an enclosing bearing housing designed with or without a cover. In the end facing the mounting of the internal bearing element, the bearing housing may be flexibly connected to the internal bearing element, for example by a bellows element. A partly protected bearing is thereby obtained, where dirt and grime are prevented from infiltrating the bearing and destroying the bearing surfaces. In a second embodiment it may also be envisaged that the internal bearing element is mounted on the V-stay and the external bearing element mounted on the wheel suspension.

The stopper element forms a substantially rectangular pin-like stopper element. In an embodiment the stopper element also comprises rounded surfaces at both its ends

at the surfaces which are not facing the locking portion of the external bearing element, for the greatest possible flexibility in the bearing.

In an embodiment the recess in the bearing housing of the external bearing element is a circumferential recess around the centre axis. The recess may also be more rectangular in shape. The locking portion of the external bearing element forms a lateral portion of this recess for interaction with the stopper element.

In an embodiment the locking portion may be composed of two diametrically opposite portions around the centre axis, i.e. not encircling the entire circumference of the external bearing element, the bearing housing. More than two locking portions may also be envisaged round the circumference. Such a solution is conceivable both where the locking portion is composed of a portion of the bearing housing or the bearing surface.

In the preferred embodiment of the invention the internal bearing element comprises an internal centre pin and a ball element comprising the external partly spherical abutment surface. The stopper element is preferably mounted at one end of the centre pin and the ball element is mounted encircling the centre pin and arranged between the stopper element and a device for mounting the centre pin. Alternatively, the stopper element may be mounted between the ball element and a means for mounting the centre pin. When brought into abutment against the internal element's spherical surface, the external bearing element will never be able to jump off unintentionally since a movement of the bearing surfaces relative to each other in a direction along the centre axis on one side is restricted by the device for mounting the internal bearing element and on the other side restricted by the stopper element and the locking portion of the external bearing element. There are several alternative ways of joining such a preferred embodiment of the bearing in the invention. One possible solution is to mount the V-stay in at least two parts along a plane. The plane for splitting the V-stay comprises the centre axis for the bearing and otherwise preferably extending in the vehicle's longitudinal direction. The two parts of the V-stay preferably form inverted parts about the plane. Alternatively, the external bearing element may comprise a releasable cover for securing to the external bearing element over the stopper element, thereby enabling a closed bearing to be formed. A further alternative is where the locking portion of the external bearing element is not circumferential, but consists of at least two portions where the stopper element can be inserted between the two portions, subsequently rotating the two elements relative to each other, and thereby locking the external and internal bearing elements to each other. A final alternative is an open bearing.

Where the V-stay is divided into two or more parts, according to an aspect of the invention the parts of the V-stay can be joined by a clamp fit round the bearing's

centre axis. Force-transmitting elements, such as ball elements or pin elements are preferably provided in the joining device. These have the accuracy and tolerance permitted in the joining device, thereby providing a correct joining of the parts forming the V-stay. According to this aspect, the parts that have to be joined comprise seat recesses in their surface where the force-transmitting elements can be mounted. The recesses normally have a different shape to the force-transmitting units. When the parts are joined, the seat recesses will be deformed so as to give a tolerance-absorbent effect, i.e. the press fit on the bearing is guiding and the seat recesses are deformed more or less as a result of the actual diameter of the bearing and bearing bore. Joining the parts in this manner by means of force-transmitting elements in the joining surface can be utilised in other applications than only for joining a V-stay in two or more parts. Alternatively, the force-transmitting units can also be secured in these recesses by a bonding material. This method of joining parts where a force-transmitting means is used between the parts may also be employed for types of connections other than split V-stays.

A second aspect according to the invention is that sensor elements are mounted in the connection of the parts comprising the V-stay. These sensor elements may be mounted in the joining device without the use of other attachment devices than the actual joining device, thus providing an advantageous and simple mounting of the sensors. These sensors can read several parameters, for example the slackness in the bearing, the joining force, etc.

The invention will now be explained by non-limiting embodiments, with reference to the attached drawings, in which:

Fig. 1 illustrates a general joining device for joining a vehicle's frame and a wheel axle,

Fig. 2 is a section through a vertical ball bearing according to the prior art,

Fig. 3 is a cross section of a first embodiment of a detail of a joining device according to the invention in a longitudinal direction of the vehicle,

Fig. 4 is a cross section in the transverse direction of the detail in fig. 3, Fig. 5 is an elevated view of a second embodiment of a joining device according to the invention,

Fig. 6 and fig. 7 are cross sections of a detail of the joining device in fig. 5, in a longitudinal and transverse direction of the vehicle,

Fig. 8 is an elevated view of the bearing in the joining device illustrated in fig. 5, with the cover removed,

Fig. 9 is a cross section of a bearing in a longitudinal direction of the vehicle in a third embodiment of a joining device according to the invention,

Fig. 10 is a cross section of the bearing in fig. 9 in a transverse direction of the vehicle, Fig. 11 is a view of a part of a V-stay that forms part of the third embodiment of the invention,

Fig. 12 is a section across the vehicle of a fourth embodiment of a detail of the joining device according to the invention,

Fig. 13 is a section along the vehicle of the fourth embodiment of the bearing in fig. 12,

Fig. 14 is a perspective view of parts of a bearing housing according to the fourth embodiment illustrated in fig. 12, and

Figs. 15A and B illustrate the principle for joining two parts by force transmission according to an aspect of the invention. Fig. 1 illustrates a joining device similar to that in the present invention for joining a frame 1 of a vehicle and a wheel axle 2. The joining device comprises a V-stay 3 with mounting points 4 for mounting to the frame 1 , normally two-point mounted ball bearings, and a bearing mounting point 5 for mounting to the wheel axle 2 which has wheels attached at two ends 6 (not shown). Fig. 2 illustrates a bearing 5 for mounting between a V-stay with a first leg 7 and a second leg 8, to a wheel axle (not shown) according to the prior art. The bearing 5 is a so-called vertical ball bearing with a centre axis 14 arranged substantially perpendicularly relative to a base for the vehicle and where the ball element is attached to the wheel axle at one end. The external bearing element 10 is mounted on the V-stay and comprises a housing 11. The housing 11 forms a closed unit round the bearing and has only one open side facing the wheel axle (downwards in the figure). In the interior of the housing 11 of a spherical bearing surface 12 is provided. This bearing surface 12 is in abutment against a ball element 16 of a internal bearing element 15. The bearing surface 12 and the ball element 16 are the wear surfaces in the bearing. The internal bearing element 15 further comprises a flange 17 for securing to the axle, this flange having a protruding pin 18 with a centre axis corresponding to the bearing. The pin 18 has an internal cavity wherein there is mounted an internal pin 19 with a substantially T-shaped cross section. The T-flange of the internal pin 19 abuts against the top of the pin 18 and in the transition between the T-shaped internal pin 19, the pin 18 and the ball element 16 there is mounted a clamping ring 20 which locks the ball element 16 relative to the pin 18. The internal pin 19 is locked in the cavity in the pin 18 by means of a

securing device 21, for example in the form of a screw arranged on the bottom of the T-shape. There is access to the securing device 21 at the bottom surface of the flange 17. Between the housing 11 and the flange surface 17 there is provided a flexible bellows 13, thus causing the bearing to be confined in a closed unit so that dirt and grime do not infiltrate the bearing.

In the further explanation of the present invention elements corresponding to the prior art explained above are given corresponding figure reference numbers or not mentioned. We shall now focus on explaining the differences between the present invention in the alternative embodiments and the prior art solution explained above. In fig. 3 and fig. 4 a first embodiment of the present invention is illustrated. The external bearing element comprises a housing 100, which has an upper opening 101, where a cover 103 is provided over the upper opening 101. The cover 103 is, for example, secured to the housing 100 by screw devices. In this embodiment the element comprising the internal bearing surface 12 can be inserted in the housing 100 through the upper opening 101 in the housing 100 and a clamp device 102 is further provided for securing the bearing surface in the housing 100. According to the invention the internal bearing element comprises a stopper element 30. The stopper element 30 is provided as a part of the internal pin 19 as an elongation and extension of the internal pin. Since a cover 103 is provided over the housing 100, the internal pin 19 with the stopper element 30 can also be inserted through the upper opening 101 of the housing 100 and secured in the pin 18 and the flange surface 17 by a securing device 21 under the flange surface 17. As indicated in fig. 4 the cover 103 is designed so that the stopper element 30 can follow the ball bearing's movements without placing unnecessary restrictions on the bearing's freedom of movement as such, this being indicated by the dotted lines 30A and 30B which indicate two possible positions of the internal bearing element relative to the external bearing element relative to movement about an axis substantially parallel to the longitudinal axis of the vehicle - i.e. a movement about a heeling axis for the vehicle. As illustrated in this embodiment the stopper element 30 has a form which is oblong with a longitudinal direction of the stopper element 30 arranged across the vehicle's longitudinal direction as illustrated in fig. 4. In other directions than the longitudinal direction of the stopper element 30, the stopper element 30 is limited and rounded so that it is not larger than necessary round the bearing. In this embodiment, the portion of the external bearing element comprising the internal partly spherical surface 12, forms the locking portion 33 of the external bearing element.

In fig. 5 a joining device is illustrated according to a second embodiment of the invention. As can be seen, the joining device comprises a first leg 7 and a second leg 8 of the V-stay which at one end comprises frame mounting points 4 and at the other common end a bearing 5 for mounting to the wheel axle. As in the first

embodiment, the external bearing element of the bearing 5 comprises a housing 100 with a cover 103. Of the internal bearing element, the flange surface 17 and the bellows can be seen, flexibly connecting the external bearing element with the internal bearing element. In figs. 6 and 7 a cross section is illustrated of the bearing 5 in the second embodiment in a transverse direction in fig. 6 and a longitudinal direction in fig. 7 of the vehicle. To a great extent this bearing resembles the bearing illustrated in the first embodiment with housing 100 and cover 103. The difference in this embodiment lies in the fact that in a plane in the longitudinal direction of the vehicle (as illustrated in fig. 7) the bearing has been given an angle α with a normal n relative to a base for the vehicle. In this application, the phrase substantially normal relative to the base should be understood to comprise such a design.

Fig. 8 is a perspective view of a bearing corresponding to that in fig. 6 and fig. 7 where the cover is removed from the housing. It can be seen here that the stopper element 30 is in the form of an oblong element with a longitudinal direction across the vehicle's longitudinal direction. The stopper element 30 is further provided with two curved portions 31, 32 relative to two planes, parallel with a base and a transverse plane for the vehicle respectively, with the result that the stopper element 30 becomes tapered towards ,the two ends of the stopper element 30 and thereby does not occupy more space than necessary, nor does it restrict the freedom of movement of the bearing more than necessary. The surface of the stopper element 30 facing the locking portion 33 (fig. 6) of the external bearing element is not curved.

Figs. 9, 10 and 11 illustrate two cross sections, in the longitudinal direction and the transverse direction respectively, of a bearing according to a third embodiment of the present invention. In this embodiment of the invention the V-stay is composed of two elements 300 which form inverted versions of each other, as illustrated in fig. 11. At their ends the V-stay parts have a half bearing housing 305, 306. These bearing housing halves 305, 306 are so designed that in a joined position they form an enclosure around the bearing with an opening facing downwards towards the flange surface 17. This means that the housing forms a total enclosure without the use of a cover as in the other aforementioned embodiments. Since the housing is divided into two halves in a plane comprising the centre axis, the internal pin 19 can be designed with a stopper element 302 in the illustrated embodiment which is a substantially cylindrical pin with a substantially circular cross section 303, which stopper element 302 is welded to the top of the internal pin 19. The two bearing housing halves 305, 306 are provided with an end recess 308 at each end of the stopper element 302, thus preventing the ends of the stopper element 302, which itself comprises curved portions 309, from restricting the freedom of movement of

the bearing. The bearing housing halves 305, 306 are provided with openings 307 for joining the bearing housing halves.

In the joining surface for the two halves or in other joining surfaces there may be devices for placing force-transmitting elements in the form of ball elements or pins (not illustrated in the fig.), which will be explained with reference to figs. 15A and 15B. The force-transmitting units 51, for example balls, are mounted in seat recesses 50, 50' in the joining surfaces of the two parts that have to be joined. The seat recesses 50, 50' are identical and opposite seat recesses and are slightly deformed by the force-transmitting unit 51 when the parts are joined, as illustrated in fig. 15B. These force-transmitting units may be designed with the tolerance permitted in the joining of the halves. The force-transmitting units and the seat projections therefore act as guiding and tolerance-absorbent devices. The force- transmitting units may also be secured in one or both halves of the seat recess. Sensors may also be provided in these or other recesses when joining the parts, the bearing housing halves, or alternatively the V-stay halves. With such a solution there is no need for other mounting devices for the sensors.

In fig. 12 and fig. 13 sections are illustrated of a fourth variant of a bearing employed in a joining device according to the invention; a section across the vehicle in fig. 12 and along the vehicle in fig. 13. This bearing differs from the other embodiments with regard to several elements. Firstly, the stopper element 405 in this embodiment is provided between a mounting device of the internal bearing element to the flange surface 17 and the ball element 16 of the internal bearing element. The bearing housing 400 of the external bearing element comprises a locking portion 401, 401' extending down and in between the stopper element 405 and the flange surface 17 as a hooked element. The bearing housing 400 is a housing without a cover corresponding to the third embodiment. The stopper element 405 may, for example, be provided as a part of the pin 18 that projects upwards from the flange surface 17, or alternatively the stopper element 405 may be a pin inserted in a bore in the pin 18. The pin 18 in this embodiment has a bore along the centre axis with internal threads 404 in a portion of the bore facing away from the flange surface 17. These internal threads 404 interact with external threads on a screw element 403 instead of the internal pin in the other embodiments. The head of the screw element 403 is in abutment against an abutment element 402, which interacts with the clamping ring 20, the pin 18 and the ball element 16 in order to hold the ball element 16 in the correct position.

Fig. 14, which shows individual elements of the external bearing element of the bearing depicted in figs. 12 and 13, best illustrates that the bearing housing 400 comprises a locking portion 401, 401 ', which is divided into two portions, a portion 401 illustrated in fig. 14, both portions 401 and 401' illustrated in fig. 12. With such a design of the locking portion 401 , 401 ' , the internal bearing element with the

stopper element can be inserted into the external bearing element with the stopper element in the gap between the locking portions 401, 401', whereupon they are rotated relative each other and the stopper element and the locking portion interact to prevent the bearing elements being released from each other by a movement along the centre axis.

The present invention has now been explained by means of non-limiting embodiments. Several variants and modifications of these embodiments may be envisaged within the scope of the invention as it is defined in the following claims. Variants of the different embodiments may be employed for all embodiments, for example a split V-stay may be employed with the ball element mounted by a screw attachment in the bore or joining device under the flange surface, or alternatively it may have an angled centre axis, the split V-stay may also have a common cover, the stopper element may be of a shape other than rectangular, such as pin-shaped, more of a triangular shape in cross section etc.