WO2006030090A1 - Bearing housing - Google Patents

Abstract

The invention relates to a housing (1) for a bearing (17), which is equipped with (i) an annular axial segment (2) that is intended to receive an outer bearing ring (19) and (ii) a radial flange (3) that is connected to one end of said axial segment. The axial segment (2) comprises means for fixing the bearing by means of radial clamping and means for axially retaining the bearing, both of said means being integral with the housing while being separated from one another circumferentially.

Description

 HOUSING FOR BEARING

The present invention relates to the field of housings for supporting bearings in mechanical assemblies comprising rolling bearings.

GB-A-I 216 146 (IBM) discloses a bearing housing for axially holding and immobilizing the outer race of the bearing in said housing by means of hooks. The housing comprises a ring provided with a radial surface in contact with a radial front surface of the outer ring of the bearing and four hooks. Each hook is provided with an inner surface adapted to be in contact with the outer surface of the bearing and extending through an inwardly directed shoulder and forming a radial retaining surface of the outer race of the bearing opposite to the ring.

As can be seen in Figures 3 and 3a, a slight gap remains radially between the outer cylindrical surface of the outer ring of the bearing and the inner surface of the hooks. The bearing is therefore not maintained radially satisfactorily. The invention aims to provide a versatile housing, lightweight, compact, monobloc, and having axial retention means of the bearing, and means for centering and effective clamping of the outer ring in the housing.

The bearing housing, according to one aspect of the invention, is provided with an annular axial portion for receiving an outer race, and a radial collar connecting to one end of the axial portion. The axial portion comprises means for fastening the bearing by radial clamping and axial retention means of the bearing. The clamping means by radial clamping and the axial retaining means are integral with said housing. The fastening means by radial clamping are separated from the axial retaining means in the circumferential direction. It is thus possible to fit the bearing in the housing with a slight radial clamping, without impairing the effectiveness of the axial retention means. Advantageously, the axial retaining means comprise a plurality of radially resilient tongues, provided at their free end with means forming an end stop in the axial direction for a radial surface of the outer ring of the bearing.

In one embodiment of the invention, the radial clamping bearing fixing means comprise a plurality of centering and clamping portions of the outer ring of the bearing. The centering portions and. The clamping means are separate from the axial retention means and are circumferentially disposed between said axial retention means. In one embodiment of the invention, the resilient tongues are arranged in windows and protrude axially into the windows from a window edge from which they are derived. The elastic tongues may fit radially in the annular envelope defined by the periphery of the axial portion. In one embodiment of the invention, the radial clamping means comprises axial bars or sectors disposed adjacent to the circumferentially locking tabs.

Advantageously, the housing comprises a bottom connecting to the axial portion opposite the radial flange. The bottom may include a central opening.

In one embodiment of the invention, the radial flange comprises fastening means on an external mechanical member. In one _. Embodiment of the invention, the housing is made of molded synthetic resin.

In one embodiment of the invention, a radial bore is provided in the axial portion for the passage of a cable. Advantageously, the housing comprises at least one sensor and an electronic card connected to the sensor. The electronic card may be arranged in a radial plane. The sensor or sensors may be arranged on a reference surface of a shoulder of the axial portion. Thus, the bearing housing comprises an annular portion for receiving an outer rolling member, for example a ring or a sleeve. The annular portion includes radial clamping bearing attachment surfaces and axial bearing retainers. The radial clamping attachment surfaces are formed in said housing. The axial retention members are integral with said housing while being spaced apart from the attachment surfaces in the circumferential direction.

In one embodiment of the invention, the attachment surfaces are supported by one-piece strips with said housing. The bars are rigid in comparison with the radially elastic axial retaining elements. The radial clamping fastening surfaces are concentric and each occupy a limited angular sector.

By separating the radial clamping means and the axial retention means in the circumferential direction, it is possible to obtain the radial clamping desired in the application in question without significant interference on the axial retaining means and while arranging the fixing means by radial clamping and the axial retaining means in a relatively small radial space. The invention also relates to an assembly comprising a housing as described above and a rolling bearing disposed in said housing. The housing may comprise at least one sensor and the rolling bearing may comprise at least one encoder, the sensor and the encoder being arranged relative to one another with a small gap.

The instrumented steering wheel device comprises a housing as described above, a rolling bearing disposed in said housing, and a central piece disposed in the rolling bearing.

The present invention will be better understood on studying the detailed description of some embodiments taken by way of nonlimiting examples and illustrated by the appended drawings, in which: FIGS. 1 and 2 are perspective views of a housing according to one aspect of the invention;

FIG. 3 is a view in axial section of a housing equipped with a bearing according to another aspect of the invention;

FIG. 4 is a detailed view of FIG. 3; and FIG. 5 is a half-view in axial section of a housing equipped with a bearing according to another aspect of the invention.

As can be seen in Figures 1 and 2, the housing is integral and made for example by molding a synthetic resin, such as a polyamide-6.6 filled with glass fibers. The housing is in the form of a housing provided with a tubular annular portion 2, a collar 3 extending radially outwardly from an axial end of the annular portion 2, and a disc-shaped radial bottom 4 disposed at the end of the annular portion 2 opposite to the flange 3. The annular portion 2 comprises a circumferentially continuous portion 5 connected to the collar 3, a circumferentially continuous portion 6 connecting to the bottom 4 and a central portion 7 disposed axially between the continuous portions 5 and 6. The central portion 7 is provided with a plurality of circumferentially uniformly distributed windows 8 of generally rectangular shape and extending from the continuous portion 5 to the continuous portion 6. A plurality of tongues 9 protrude axially in the windows 8 from the continuous portion 5. In other words, the tongues 9 are supported by the continuous portion 5 and occupy most of the surface of the windows 8 leaving free a U-shaped space on the axial sides of the tongues 9 and on their free end.

In the embodiment shown, there is provided a tongue 9 per window 8. However, in a variant, provision can be made for only a portion of the windows 8 to be occupied by a tongue 9. The tongues 9 have a general axial shape and end near the continuous portion 6 by a hook 10 projecting radially inwardly. The hooks 10 have an inclined chamfer 11 starting from the free end of the hook 10 and connecting to the body of the tongue 9 in the direction of the continuous portion 5. Alternatively, there may be provided a hook 10 having a substantially radial free edge. The free end of the hook 10 opposite the continuous portion 5 is substantially radial. The central portion 7 comprises a plurality of bars 12 remaining between the windows 8 and connecting the continuous portions 5 and 6, one to the other. The bars 12 occupy an angular sector sufficient to ensure the rigidity of the housing. The bars 12 are provided with an annular inner surface 13 centered on the axis of the housing and to receive the outer surface of an outer race ring providing a precise radial wedging. The bars 12 have a high rigidity, unlike the tongues 9 which have a certain radial flexibility allowing them to erase radially temporarily during mounting of an outer race ring.

It is further provided notches 14 formed from the outer edge of the flange 3 to facilitate the attachment of the housing 1 to another mechanical part, for example by means of screws not shown. On the other hand, the bottom 4 comprises an outgrowth projecting radially outwards and occupying a limited angular sector to form a cable outlet. The protrusion 15 is provided with a window 15a through which an electric cable, not shown, can pass. On the opposite side to the protrusion 15, the bottom 4 is provided with a notch 16 projecting inwards to which corresponds, inside the housing 1, a not visible projection in Figures 1 and 2 forming a surface reference for a sensor.

Thus, the inner surfaces 13 of the bars 12 form means for fixing and centering by radial clamping of a mechanical part having an outer cylindrical surface, for example a bearing. The resilient tongues 9 form axial retention means of the same mechanical part, the axial retaining means being circumferentially separated from the radial clamping means formed by the inner surfaces of the bars 12, in that the tongues 9 are supported by the portion continues 5 while being distant from the bars 12.

In the embodiment illustrated in FIGS. 3 and 4, the housing 1 is associated with an instrumented bearing 17 for an electrically controlled steering wheel. The bearing 17 includes an inner ring 18, an outer ring 19, a row of rolling elements 20, for example balls, held by a cage 21 with regular circumferential spacings, a seal 22 and an encoder 23. The inner and outer rings concave rolling tracks for the rolling elements 20, respectively on their outer and inner surfaces, made for example by machining with chip removal, the inner ring 18 has a cylindrical bore and two opposite radial end surfaces. The outer ring 19 has a cylindrical outer circumferential surface 19a, in which is provided an annular groove 24 spaced from the radial end faces of said outer ring 19. The seal 22 is mounted in a stepped bearing surface of the outer ring 19 and rubs with a flexible lip on an outer cylindrical surface of the inner ring 18 in the vicinity of one of the front radial surfaces.

On the other side, the encoder 23 is mounted on the outer cylindrical bearing surface of the inner race 18 provided between the raceway and the corresponding radial surface with which said encoder is also in contact so as to ensure its axial positioning. The encoder 23 comprises a support portion 24 and an active portion 25, for example in the form of an over-molding of plastoferrite or elastoferrite. The bearing 17 is disposed in the central portion of the annular portion 2, the cylindrical outer surface 19a of the outer ring 19 being fitted into the inner surfaces 13 of the bars 12. The bearing 17 is thus positioned radially relative to the housing 1. hooks 10 of the tongues 9 are arranged on a fictitious circle having, when the tongues are in the free state, a diameter smaller than the diameter of the inner surfaces 13 of the bars 12. The hooks 10 thus project into the groove 24 of the outer ring 19 and prevent any movement to separate the bearing 17 from the housing 1 by an axial movement to move the bearing 17 away from the bottom 4. For this purpose, the edges of the groove 24 are substantially radial and the end free hook 10 is also substantially radial, thus forming an axial stop against disassembly. Furthermore, the notch 16 formed in the bottom 4 is translated on the inside of the housing 1 by a shoulder provided with a radial surface 16a against which the front radial surface of the outer ring 19 located opposite the gasket. sealing 22 comes wearing. The bearing is therefore well maintained axially in the housing 1, being retained axially by the hooks 10 and being positioned axially accurately by the radial surface 16a.

The housing is particularly compact radially. Indeed, the tongues 9 fit radially into the thickness of the bars 12 ensuring the tightening of the outer ring. The extra thickness of the free ends of the tongues 9 is disposed inwards in order to interfere with the groove 24 of the outer ring 19 of the bearing 17. The tongues 9, which can flex freely inside the windows 8 in the radial direction without risk of breaking, allow easy mounting of the bearing 17 in the housing 1 by a simple axial movement. The bearing 17 is perfectly centered in the housing 1 by the plurality of lugs 12 which have both sufficient rigidity to ensure the centering and the minimum radial flexibility to support the tight fitting of the bearing.

The initial interference clamping will be chosen so that even in case of dimensional variations of the housing and / or bearing due to thermal and / or hygrometric variations, there is still sufficient radial interference bearing / housing. The structure in strips 12 is a little less rigid radially than a continuous circular range and allows a fitting with relatively large initial radial interference.

As illustrated in Figures 3 and 4, the bottom 4 is used to support a printed circuit board or integrated circuit 26 arranged radially on which are connected one or more sensors 27, for example Hall effect cells. The sensor or sensors 27 are arranged facing the active part 25 of the encoder 24 with a small radial air gap, said active part 25 forming a multipole magnetic ring which rotates in front of the sensor or sensors 27 in order to provide a magnetic field variation. representative of the rotation of the inner ring 18.

The sensor 27 visible in Figures 3 and 4 is located behind the cutting plane used for these drawings. The system is completed by a central mechanical part 28 mounted tightly in the inner ring 18 and provided on the side opposite the bottom 4 of two threaded holes 29 for fixing a control wheel by means of screws not shown. The central piece 28 comprises a radial end 28a facing the circuit board 26 and disposed axially at the inner ring 18, a cylindrical bearing surface 28b fitted into the bore of the inner ring 18 and connected to the radial end 28a, an annular radial surface 28c in contact with the front radial surface of the inner ring 18 on the seal side 22 and connecting to the cylindrical fitting seat 28b, and an outer cylindrical surface 28d of large radially located substantially at the level of the seal 22, connecting to the annular radial surface 28c, and on which is rubbed a seal 30 fitted in the continuous portion 5 of the annular portion 2 of the housing 1. The seal 30 seals and generates a couple of friction favoring smooth and regular handling of the wheel by an operator.

The assembly can be carried out as follows. The circuit board 26 supporting the sensor or sensors 27 is fixed in contact with the bottom 4 of the housing 1, the sensor or sensors 27 resting on a reference surface provided by origin by molding on the inside of the housing 1, so that the sensor or sensors 27 are located radially with the desired air gap with respect to the encoder 23. The bearing 17 provided with the encoder 23 is pushed axially into the housing 1 until the bearing 17 comes to a stop in the housing 1 against the radial surface 16a.

The locking tongues 9, after being erased radially outwards, penetrate into the groove 24 of the outer ring 19 of the bearing 17. The bearing being perfectly centered in its housing via the lugs 12 the radial air gap between the sensor (s) 27 and the active part 25 of the encoder 23 is thus perfectly controlled. This contributes to a greater reliability of the detection system. The inlet seal 30 is then put in place, the central piece 28 having been previously fitted into the inner ring 18 of the bearing 17. All that remains then is to mount the subset thus formed on the mechanical support which the receives via the mounting flange 3 and mount the flywheel on the central part 28 by two screws.

The embodiment illustrated in FIG. 5 applies to a rolling bearing of the conventional, non-instrumented type. The bearing 17 is then provided with two seals 22 and 30, symmetrical with respect to a radial plane passing through the center of the rolling elements 20. The bearing 17 is devoid of an encoder. The housing 1 is similar to those of the previous embodiments, except that the bottom 4 is free of protrusion 15 and notch 16 and has one. annular form with a bore 4a for the passage of a shaft 31 on the outer surface of which the inner ring 18 is fitted by its bore.

Thanks to the invention, the housing is particularly compact radially, versatile in many applications, providing effective axial retention, reliable by the flexibility of the tabs which are not likely to break during the introduction of the bearing, and allowing a very good centering and an excellent maintenance of the bearing in the bars of fitting.

Claims

Bearing housing (1) provided with an annular axial portion (2) for receiving an outer race ring (19) and a radial collar (3) connected to an end of said bearing axial portion, characterized in that the axial portion (2) comprises radial clamping bearing fixing means and axial bearing retaining means, the radial clamping fastening means and the axial retaining means being integral with said housing while being separated from each other in the circumferential direction. 2-housing according to claim 1, characterized in that the axial retaining means comprise a plurality of tongues (9) radially resilient, provided at their free end with means forming a stopper in the axial direction for a radial surface of the outer ring of the bearing. 3-housing according to claim 2, characterized in that the elastic tongues (9) are arranged in windows (8) and protrude axially in said windows from a window edge from which they are derived. 4-housing according to claim 2 or 3, characterized in that the elastic tongues (9) are inscribed radially in the annular envelope defined by the periphery of the axial portion (2). 5-Housing according to any one of claims 2 to 4, characterized in that the fastening means by radial clamping comprise axial webs (12) or sectors arranged adjacently to the tongues (9) in the direction circumferential. 6-housing according to any one of the preceding claims, characterized in that the fixing means of the radial clamping bearing comprise a plurality of portions of centering and clamping of the outer race of the bearing, said centering and clamping portions being distinct from the axial retaining means and circumferentially disposed between said axial retaining means. 7-housing according to any one of the preceding claims, characterized in that it comprises a bottom (4) connected to the axial portion opposite the radial flange (3). 8-housing according to claim 7, characterized in that the bottom (4) has a central opening. 9-housing according to any one of the preceding claims, characterized in that the radial flange (3) comprises fastening means on an external mechanical member. 10-housing according to any one of the preceding claims, characterized in that it is made of molded synthetic resin. 11-housing according to any one of the preceding claims, characterized in that a radial bore (15a) is formed in the axial portion for the passage d.'jjn, cable .. . 12-housing according to any one of the preceding claims, characterized in that it comprises at least one sensor (27) and an electronic card (26) connected to said sensor. 13-housing according to the preceding claim, characterized in that the electronic card is arranged in a radial plane. 14 - assembly comprising a housing according to any one of the preceding claims and a rolling bearing disposed in said housing. 15-assembly according to the preceding claim, characterized in that the housing comprises at least one sensor (27) and the rolling bearing comprises at least one encoder, the sensor and the encoder being arranged relative to one another with a low air gap. 16-instrumented steering wheel device comprising a housing according to any one of the preceding claims, a rolling bearing disposed in said housing, and a central piece (28) disposed in the rolling bearing.