TECHNICAL FIELD OF THE INVENTION This invention relates to a rolling bearing assembly comprising, amongst others, a sensor adapted to detect a rotation parameter of a first ring of a rolling bearing with respect to a second ring of this rolling bearing. The invention also relates to a process for manufacturing such a rolling bearing assembly.

BACKGROUND OF THE INVENTION

A rolling bearing generally comprises an inner ring, an outer ring and several rolling bodies installed between these two rings. These rolling bodies can be balls, rollers or needles. In the meaning of the present invention, a rolling bearing can be, for instance, a ball bearing, a roller bearing or a needle bearing. In the field of rolling bearings, it is known to use a tachometer in order to determine the rotation speed of a member supported by a rolling bearing. In such a case, a sensor is generally mounted on a support member which has to be immobilized with respect to one of the rings of the rolling bearing, the so-called "fixed ring". For instance, WO-A-2007/122303 discloses an instrumented roller bearing device including an encoder washer fixed on the inner ring of a rolling bearing and a sensor facing a magnetic part of this encoder washer. This sensor is mounted on an annular printed circuit board. Opposite the sensor with respect to a central axis of the bearing, the printed circuit board is crossed by three pins which extend parallel to the central axis of the bearing and form connection means for the printed circuit board.

SUMMARY OF THE INVENTION

This invention aims at improving the simplicity and compactness of a rolling bearing assembly while allowing efficient detection of a rotation parameter. To this end, the invention concerns a rolling bearing assembly comprising a rolling bearing with an inner ring, an outer ring and several rolling bodies between the inner and outer rings, at least one sensor adapted to detect a rotation parameter of a first ring with respect to a second ring of the rolling bearing and a support member holding the sensor in position with respect to the rolling bearing.

According to the invention, the support member holds the sensor in a position such that at least one connecting pin of the sensor extends in a volume defined by the support member and adapted to accommodate an electrical connector. Thanks to the invention, one does not need a printed circuit board to support the sensor which can be directly connected to an external cable, via its respective pin or pins, in order to deliver an output signal to an external electronic control unit.

According to advantageous aspects of the invention which are not compulsory, such a rolling bearing assembly can incorporate one or several of the following features:

- The sensor is provided with several connecting pins, each of the pins extending in the volume adapted to accommodate an electrical connector, when the sensor is held by the support member.

- The support member forms a housing for the reception of a body of the sensor in a position where the pin or pins extend within the volume defined by the support member and adapted to accommodate an electrical connector.

- The body is immobilized in the housing by cooperation of shapes.

- The support member is locally expanded by the introduction of the body within the housing. - The support member is immobilized on the rolling bearing by cooperation of shapes, in such a way that the housing is contracted around the body.

- A part of the support member is partly engaged and contracted within an inner volume of the outer ring and the housing is partly defined by this part of the support member. - The housing communicates with the volume via an opening through which the pin or pins extends or extend.

- The sensor is located radially outside or inside of the encoder washer and is oriented in such a way that its principal detection direction is radial with respect to the axis of rotation of the first ring. The invention also concerns a process for manufacturing a rolling bearing as mentioned here-above and, more particularly, a process for manufacturing a rolling bearing assembly comprising a rolling bearing with an inner ring, an outer ring and several rolling bodies between the inner and outer rings, at least one sensor adapted to detect a rotation parameter of a first ring with respect to a second ring, and a support member holding the sensor in position with respect to the rolling bearing. According to the invention, the process includes at least the steps of: a) inserting the sensor into a housing of the support member with at least one connecting pin of the sensor going through an opening contiguous to the housing, b) pushing the pin through the opening, so that it extends in a volume defined by the support member and adapted to accommodate an electrical connector, and c) mounting the support member equipped with the sensor onto one ring of the rolling bearing.

Advantageously, during step c), the support member is partly introduced within an inner volume of the outer ring and the housing is contracted around a body of the sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood on the basis of the following description which is given in correspondence with the annexed figures and as an illustrative example, without restricting the object of the invention. In the annexed figures:

- figure 1 is a perspective view of a rolling bearing assembly according to the invention;

- figure 2 is a perspective view similar to figure 1 when the rolling bearing assembly is connected to an electrical cable;

- figure 3 is a partial cut view along plane III on figure 2;

- figure 4 is a perspective exploded view of the rolling bearing assembly and cable represented on figures 2 and 3; and

- figure 5 is a perspective exploded view, from a different angle, of the elements represented on figure 4. DETAILED DESCRIPTION OF SOME EMBODIMENTS The rolling bearing assembly 2 represented on figure 1 to 5 includes a rolling bearing 4 which comprises an outer ring 6, an inner ring 8 and seven balls 10 held in position by a cage 12 in an annular chamber 14 defined between the inner radial surface of outer ring 6 and the outer radial surface of inner ring 8.

Ring 8 is supposed to rotate with respect to ring 6, around a central axis X ₂ of rolling bearing assembly 2.

In the present description, the words "axial", "radial", "axially" and "radially" relate to axis X ₂ . A direction is "axial" when it is parallel to this axis and "radial" when it is perpendicular and secant with this axis. A surface is radial when it is perpendicular to a set of straight lines which are radial with respect to axis X ₂ .

A sealing device 16 extends between rings 6 and 8 on one side of rolling bearing 4. This sealing device isolates annular chamber 14 from the outside atmosphere. An encoder washer 20 is fixedly mounted on inner ring 6 by cooperation of shapes and/or by magnetic effect. Encoder washer 20 has at least two magnetic poles and rotates with ring 8 around axis X ₂ .

A sensor 30 is held by a support member 40 with respect to outer ring 6. Sensor 30 includes a Hall effect cell and it is adapted to detect the variation of the electromagnetic field induced by the rotation of encoder washer 20. Thus, sensor 30 is adapted to detect a rotation parameter of ring 8 with respect to ring 6.

Rolling bearing assembly 2 includes rolling bearing 4 and items 20, 30 and 40.

A rotation parameter of one ring with respect to the other is a parameter which is representative of a pivoting movement of these rings, one with respect to the other. Such a parameter can be an angle measuring the angular position of one of the rings with respect to the other, around axis X ₂ . Such a parameter can also be a speed, a displacement, an acceleration or a vibration.

According to an embodiment of the invention which is not represented, encoder washer 20 and sensor 30 could be mounted so that they allow to detect the rotation of outer ring 6 with respect to inner ring 8, which is appropriate in case of a rolling bearing with a so-called inner fast ring and a so-called outer rotating ring. Sensor 30 has a main detection direction D ₃₀ which is radial with respect to axis X2 and it is oriented towards axis X2, as shown by arrow A ₃₀ on figure 3. Sensor 30 is located radially outside of encoder washer 20 and it is roughly axially aligned with encoder washer 20. According to a non represented embodiment of the invention, sensor 30 can be located radially inside of encoder washer 20, while it is also aligned axially with respect to this washer, the main detection direction of sensor 30 being also radial but the sensor being oriented so that an arrow similar to arrow A ₃₀ is directed away from axis X ₂ . Sensor 30 has a body 32 which includes a Hall effect detection cell and three pins 34, 36 and 38 which extend parallel to each other with respect to body 32. These pins extend parallel to axis X ₂ when rolling bearing assembly is mounted.

A housing 42 is provided in support member 40 in order to accommodate body 32 of sensor 30. Housing 42 has a shape which corresponds to the shape of body 32. Support member is made of synthetic material, e.g. PA66 and the nominal shape of housing 42 is such that it is slightly expanded when body 32 is introduced within housing 42 so that body 32 is held, both elastically and by cooperation of shapes, within housing 42.

Housing 42 communicates by an opening 44 with a volume 46 defined within a socket 48 of support member 40. Volume 46 is adapted to accommodate a connector 100 mounted at one end of an electric cable 102 used to connect sensor 30 to a non represented electronic control unit. Cable 102 includes three individual conductors 104, 105 and 106 whose extremities are stripped in order to be electrically connected to respective conducting clamps 108 fixed within connector 100 as shown on figure 3. On figure 3, the electrical connection between the stripped end of connector 104 and the corresponding clamp is not visible.

The fond face of connector 100 is provided with three openings 109 giving access to three clamps 108 which are aligned along a direction D100 defined by connector 100. Direction D _1O o is perpendicular to a longitudinal axis X ₁₀₀ of connector 100 which is parallel to the direction of introduction of connector 100 within volume 46. Connector 100 is provided with two lateral protrusions 107 adapted to be received within corresponding slits 47 of socket 48. Pins 34, 36 and 38 are aligned along a direction D ₃₀ defined by body 32. When sensor 30 is mounted on support member 40 with its body 32 received in housing 42, direction D ₃₀ is imposed by the geometry of sensor 30 and housing 42. The geometry of parts 30, 40 and 100 is such that when sensor 30 is mounted on support member 40, its three pins 32, 36 and 38 extend within volume 46 in a position which is compatible with the introduction of connector 100 within this volume so that each pin 34, 36 and 38 penetrates an opening and is electrically connected to a respective clamp 108, thus to a respective conductor 104, 105 or 106 of cable 102. In other words, support 100 holds sensor 30 directly, that is without making use of a printed circuit board, in a position which allows direct connection between this sensor and electrical cable 102, via pins 34, 36 and 38 and connector 100.

Such a construction is simple, inexpensive, reliable and improves the compactness of rolling bearing assembly 2 which can be easily connected to a cable 102 equipped with a corresponding connector 100.

Support member 40 is mounted on outer ring 6 by engagement within an inner radial volume 62 of outer ring 6 which is delimited by an inner flange 64 of this ring. The geometry of support member 40 and flange 64 is such that support member 40 is radially contracted towards axis X ₂ when it is introduced within volume 62. This implies that housing 42 is contracted around body 32 so that sensor 30 is firmly held in position with respect to rolling bearing 4 and encoder washer 20.

As shown on figure 5, housing 42 is opened towards axis X ₂ , so that sensor body 32 can be directly opposite to encoder washer 20, without interference of a wall of support member 40 which would otherwise extend between items 20 and 30.

Manufacturing of rolling bearing assembly 2 starts with manufacturing rolling bearing 4 in a classical way. Then encoder washer 20 is fixedly mounted on inner ring 8. On the other hand, sensor 30 is introduced within housing 42, in the direction of arrow A ₁ on figure 5 so that its pins 34, 36 and 38 go through opening 44 and penetrate within volume 46. This is obtained by pushing body 32 within housing 42. Then, support member 40, which has been equipped with sensor 30, is mounted on outer ring 6 by introducing a radial bead 41 of support member 40 within volume 62 of outer ring 6. This is obtained thanks to a radial contraction of support member 40, which firmly holds support member 40 with respect to rolling bearing 4 and increases the blocking effort of sensor body 32 within housing 42.

As shown on figure 5, bead 41 is interrupted at the level of housing 42, so that support member is easily deformable at the level of a wall 43 of support member 40 which radially surrounds housing 42. Wall 43 is more flexible than bead 41 and it is also partly introduced within volume 62, so that support member primarily contracts at the level of housing 42 when it is mounted onto ring 6.

Rolling bearing assembly 2 is then in the configuration of figure 1 where a connector 100 can be easily introduced within volume 46 when it is necessary to connect sensor 30 to a non represented electronic control unit.

The invention is described here-above and represented on the figures with balls as rolling bodies. It can however be used with other kinds of rolling bodies, e.g. rollers or needles.

The invention has been represented here-above in case all connecting pins

34, 36 and 38 of sensor 30 extend within volume 46 which is adapted to accommodate electrical connector 100. According to a non represented embodiment of the invention, only some of these pins, or even one of these pins, can extend in this volume.