Field of the Invention
The invention relates to the assembly of a vehicle non-driving wheel hub equipped with a pulser and sensor device for measuring the speed of rotation of the wheel.
Prior Art
Such an assembly is already described in French patent application No. 87.15794 in the name of the applicant. In this prior device, the integral rolling bearing is axially immobilized on the stub axle by axial tightening of the internal rings of the bearing between a shoulder of the stub axle and a stop nut located on the wheel side of the vehicle, inside the rolling bearing. This arrangement of the stop nut has several drawbacks, in particular that of taking up considerable room inside the space available in the rolling bearing, which entails the use of miniaturized sensors to measure the speed of the wheel. Furthermore, the sensor and its connection, as well as the closing cap, necessarily have to be put into place after this stop nut has been tightened, after the hub has been mounted on the vehicle.
Summary of the Invention
The object of the invention is to remove the above drawbacks, in particular to leave more room free in the hub for the sensor, and to enable this sensor and the closing cap to be mounted prior to the installation of the whole on the vehicle.
For this purpose, the invention consists, while continuing to make use of an integral rolling bearing of the type aforementioned, in mounting it with the help of a stub axle comprising at its end located on the wheel side a shoulder flange that is housed inside the hub and, at its other end, a threaded portion enabling the stub axle to be tightened on the stub axle carrier, after introducing this stub axle ready equipped with its rolling bearing through the said stub axle carrier.
Thanks to this arrangement and to the greater amount of room available inside the hub, the sensor does not need to be miniaturized and it can be mounted in advance with its connection end piece in the axis of the stub axle.
The closing cap can also be mounted in advance in the workshop and it can advantageously be integrated with the pulser.
The Drawings
Other features of the invention will become apparent form the following description of various forms of embodiment taken as examples and shown on the attached drawings, wherein:
FIG. 1 is an axial cross-sectional of a first form of embodiment;
FIG. 2 is a corresponding axial cross-section of a second form of embodiment;
FIG. 3 is an end view of the corresponding sensor;
FIG. 4 is an axial cross-section of a third form of embodiment;
FIG. 5 is an end view of the corresponding sensor;
FIG. 6 is an axial cross-sectional of a final form of embodiment;
FIG. 7 is a larger scale detail of a fragment of FIG. 6; and
FIG. 8 is an enlarged front view of a fragment of the corresponding pulser of FIG. 7.
Detailed Description of the Invention
As can be seen from FIG. 1, the integral rolling bearing, which is of the same type as in the aforementioned patent application and which includes, in particular, an outer hub-forming ring 1 and two internal rings 2 and 3. The essential difference is that, according to the invention, the stub axle 4 comprises on its end towards the wheel 5 a shoulder flange 6, of small size, which presses the assembly of internal rings 2 and 3 against the stub axle carrier 7. For this purpose, the other end of the stub axle 4 comprises a threaded portion 8 onto which can be screwed a stop nut 9. To enable the stub axle 4 to be rotationally immobilized while this nut 9 is being tightened, use can be made, for example, of flats 10.
The first consequence is that it is possible to have far more room inside hub 1 to house the sensor 11 which, as a result, does not need to be miniaturized but can, on the contrary, be constituted by a conventional larger sensor which, in the current state of the art, is far less expensive, less fragile and easier to put into place than miniaturized sensors.
In particular, this sensor 11 can advantageously be integrated in a sensor holding plug 12 of plastic material extending in the axis of the stub axle by a shank 13 in the end of which is integrated a female socket 14 for a connecting plug 15, improving and facilitating the electrical connection of the sensor 11 once the whole is mounted on the vehicle, with the help of a connecting cable 16 terminated by the plug 15. An elastomer plug 17, moulded or bonded onto the wire 16 is used to ensure tightness and to improve fixation.
Also thanks to this arrangement, the unit comprising the stub axle, the sensor 11 and the sensor holding plug 12 with its connection 14, and also the closing cap 18 of the hub, can be integrated in advance in the unit comprising the assembly to be installed on the vehicle, which facilitates both manufacture and final installation.
The pulser 19 can advantageously be machined in the protective cap 18, if the latter is of ferromagnetic material, simply by cutting out therein in its cylindrical portion a series of rectangular orifices, as in the examples in FIGS. 1, 2, and 4.
A closing part 20 can further be fitted into the hub 1 to leave only a narrow gap between its radial portion and the periphery of the internal rolling bearing rings 2, in order to ensure better retention of the grease of the rolling bearing.
In the example shown in FIG. 1, the sensor holder 12, made as we have seen from moulded plastic material, as well as its shank 13, is fixed by simply fitting into the internal bore of stub axle 4.
In the variant shown in FIGS. 2 and 4, this fixing is effected by screwing respectively one threaded portion 21 screwing inside the bore of stub axle 4, in the example shown in FIG. 2, or a threaded portion 22 screwing on the outside of the shoulder flange 6 in the example given in FIG. 4.
Furthermore, in these two examples, the sensor holder 12 can advantageously comprise an enclosing periphery 23 performing the same function as the retaining part 20 in FIG. 1, except that the narrow gap ensuring the retention of the grease is on the outside as this part is non-rotating.
To screw the sensor holder 12 in these last two examples, use can be made, for example, of a spanner with pins penetrating orifices 24 as represented in FIG. 3, or notches 25 as represented in FIGS. 4 and 5.
Furthermore, in the example given in FIG. 4, it has been shown how to improve the mechanical retention of the sealing plug 17 using a circlip 26 housed in a groove machined in the internal bore of the stub axle 4, close to the threaded end 8. This last solution prevents positively any likelihood of the wire 16 being pulled out accidentally.
Finally, in the example of embodiment in FIG. 6, the pulser is formed in the rotating closing piece 20. The sensor 11 is orientated parallel to the axis of sensor holder 12. The sensor 11 senses the slots 27 cut out in the radial portion of the metallic part 20. In this case, to ensure that this part continues to perform its closing and grease retaining function, there can advantageously be moulded thereon an elastomer part 28 which closes all the slots 27 and further constitutes an actual sealing lip 29 bearing on the internal ring 2 as shown in FIG. 7.
In all cases, the invention thus makes it possible to improve both production and assembly costs, at the same time as the reliability of unit, once mounted on the vehicle.