FR2614955A1 - BEARING FOR SUPPORTING A ROTATING MEMBER, PARTICULARLY FOR A WHEEL OF A VEHICLE AND MANUFACTURING METHOD THEREOF - Google Patents

Abstract

THE INVENTION RELATES TO A BEARING 1, WHICH CAN SUPPORT A ROTATING BODY, FOR EXAMPLE A WHEEL 2 OF A VEHICLE, AND SIMULTANEOUSLY ALLOWS THE DETECTION OF THE ANGULAR SPEED OF SAID ROTATING BODY BY MEANS OF AN ELECTROMAGNETIC SENSOR 21, FOR EXAMPLE FORMING PART OF AN ANTI-LOCK SYSTEM OF THE ABS TYPE; ITS MAIN CHARACTERISTIC IS THE PRESENCE ON ONE 3 OF THE BEARING RINGS WHICH CAN BE FIXED FOR ROTATION WITH THE ROTATING BODY, OF AN ANNULAR GROOVE 12 WHICH IS FILLED WITH A PASTE 13 CONTAINING FERROMAGNETIC MATERIAL, WHICH IS THEN SHAPED IN THE SHAPE OF A TOOTH RING 14 AND CAUSES TO SOLIDIFY TO CAUSE THE PRESENCE INSIDE THE GROOVE 12 OF A SOLID FERROMAGNETIC SUBSTANCE DEFINING A PLURALITY OF SUCCESSIVE PEAKS AND TROUGHS.

Description

The present invention relates to an improved bearing,

  especially for vehicle wheels, capable of supporting

  carry a rotating organ and simultaneously allow

  the detection of the angular speed of this rotating organ

  tion by means of an electromagnetic sensor, for example forming part of a control circuit such as an anti-lock braking circuit of the ABS type. The present invention further relates to a simple and economical method

of production of said bearing.

  It is known that at present, in particular on sports motor vehicles or so-called "grand touring" vehicles, special control circuits are installed.

  of the type known as ABS intended to prevent blocking

  age of vehicle wheels during braking; these circuits

  include, as we know, a functional part hy-

  hydraulics acting by means of valves on the brake circuits, and an electronic control part capable

  to bring the functional part to intervene when a

  differential riation of the speed of rotation of the wheels of each axle of the vehicle is detected greater than one

  predetermined threshold; these speed variations are detected

  ted by a suitable known circuit using sensors

  electromagnetic, at least one for each vehicle wheel

  cule, which emit a pulse signal proportional to the speed of rotation of the wheel they control; the signal

  of impulses is obtained in the majority of cases in

  so much, usually on the wheel support bearing, a toothed member known in the art as "wheel

  sonic "or" pulse ring "; this organ includes

  essentially a flange of ferromagnetirue material fixed to rotate with the wheel and provided with a toothed ring in correspondence with which the sensor is mounted; during the rotation of the wheel, therefore, the alternating passages in front of * the sensor of the solid parts formed by the teeth and

  the voids formed by the space between the provo-

  quent a periodic variation of the air gap between the flange and the sensor, and therefore, a periodic variation of the magnetic field with consequently the generation by the sensor of

  periodic oscillating signal whose frequency is

  tional to the speed of rotation of the wheel.

  A disadvantage of the detection system described above

  above results from the large volume of the sonic wheel and its cost, which is also high, given that this wheel, because of the precision with which it must be produced, must be formed entirely by material removal operations ; the need to mount an additional member such as a sonic wheel also makes the assembly and maintenance operations of the assembly of

  the mechanical suspension assembly of the vehicle more com-

  plexes and ultimately increases the weight of the suspension itself and therefore the mass displaced by the roughness of the ground during vehicle movements, with the resulting reduction in the response of the suspension to

  constraints, and therefore a reduction, even if it is done

  ble, handling that on the other hand we want to increase

ter.

  The object of the invention is to provide an additional bearing

  port for a rotating member, and in particular for a vehicle wheel, formed so as to allow the elimination of the sonic wheel, and consequently, which can be implemented to incorporate its function so as to be capable

  to support the wheel, connecting it to the vehicle suspension

  hicle, and cooperate with a sensor to allow the detection of the angular speed of the wheel itself. Another object of the invention is also to provide a simple and inexpensive process for the production of a bearing of this type. Said objects are achieved by the invention which provides a support bearing for a rotating member, in particular for a vehicle wheel, characterized in that a ring of said bearing, which can be directly connected for rotation with said member rotation, is

  provided at least on the outside with an annular groove

  partially filled with a solid substance; said solid substance having been formed inside said annular groove substantially in the form of a toothed ring so as to

  define, parallel to a bottom wall of said groove

  re annular and on the opposite side thereof, inside said annular groove, a plurality of

  peaks and troughs with a regular succession.

  The invention further relates to a method of producing

  tion of a support bearing for a rotating member which can be used to allow detection

  of an angular speed of such an organ by means of a cap-

  sensor, for example an electromagnetic sensor,

  laughed at by the fact that it comprises the following steps: - forming an annular groove on the outside of a ring of said bearing which can be connected for rotation with said rotation member; pouring into said annular groove a fluid substance in the pasty state; plastically working said fluid substance inside said annular groove so as to form in the fluid substance a regular succession of peaks and valleys; and -allowing said fluid substance to harden inside said groove after having worked it,

  so as to form therewith, inside said rai-

  nure, a substantially toothed ring.

  For a better understanding of the invention, we

  now gives a non-limiting description of a mode

  of realization thereof with reference to the drawings an-

on which:

  Fig.l shows in perspective a bearing formed se-

  lon the principles of the invention and, schematically, its two stages of production; and Fig. 2 is a view in partial longitudinal section

of the bearing of figure 1.

  Referring to Figures 1 and 2, a support bearing for a vehicle wheel 2 not shown for simplicity

  cited or for any other type of rotating organ, is in-

  generally indicated by the reference number 1; the bearing represented by means of a nonlimiting example is of the type

  said to be "second generation" and therefore includes a ring ex-

  upper 3 provided with a radial outer flange 4 facing the wheel 2 and on which the wheel 2 itself is

  fixedly mounted in a known manner, and an integrated ring -

  laughing 5, preferably formed of two half-rings 6 and 7,

  which can be fixedly fixed angularly

  known method not shown for simplicity with a

  constant speed seal if wheel 2 is a drive wheel

  this, or with a simple support pin if the wheel 2 is not driving; in known manner, between the rings 3 and 5 are interposed the respective sealing members 9 and 10 and the rolling bodies, which may be constituted for example by balls 8; the flange 4 includes through holes 11 for direct attachment to the wheel 2 so that the outer ring 3 also performs the hub function; it is obvious, however, that this configuration is not limiting and that what is described below can therefore be applied to any bearing of any type. In

  particular, according to the invention, the bearing 1 has a year

  neau which can be mounted to rotate with the support member, in this case the outer ring 3 is provided on the outside with an annular groove 12 which is filled, at least partially, with a solid substance 13 firmly fixed in the groove 12 and shaped so as to substantially form a toothed ring 14 (Figure 1); in particular, the solid substance 13 completely fills the groove 12 in certain places, so as to define inside

  this, parallel to a bottom wall 15 of the rail

  nure 12 and on the side opposite the bottom wall itself

  a series of peaks and valleys arranged in successive succession

  gulière, formed by the respective teeth 16 and the respective spaces 18 arranged alternately along any

the extent of the groove 12.

  In a preferred embodiment the substance so-

  lide 13 of which the toothed ring 14 is fixedly housed

  in the groove 12 consists of a solidified paste

  taking a matrix formed of a resin of synthetic material

  polymerized tick and dispersed filler

  in the matrix and consisting of a ferromagnetic substance

  powder or granular tick, for example consisting of iron filings; the annular groove 12 is preferably formed frontally on one end 20 of the outer ring 30 opposite to that on which the wheel 2 is mounted and equipped with the flange 4; if the dimensions of this

  end 20 are not sufficient to accommodate a quan-

  solid substance 13 in order to form a toothed ring 14 of sufficient size to cooperate with a sensor 21, in the example shown an electromagnetic sensor of any known type, for carrying out the detection of the speed of rotation of the ring 3, and with it,

  wheel 2, end 20, in a possible variant of the pa-

  link object of the invention can be provided on its exté

  laughing at a flange 22 projecting radially similar to

  the flange 4 but smaller, shown in broken lines

  pu in Figure 2, in which is formed, frontal-

  ment, a groove 12 of appropriate dimensions. In

  service, the bearing 1 is mounted in a known manner, not shown

  presented for simplicity, to the vehicle suspension and the wheel 2 is mounted there; opposite the toothed ring 14 is placed the sensor 21 which, in the example shown, consists substantially of a simple electromagnet connected in a known manner not shown for simplicity to an electronic oscillating detector circuit of a known type and therefore not shown either for simplicity; during the rotation of the wheel 2 the teeth 16 and the spaces between the teeth 18 pass successively in front of the sensor 21 and, being made of ferromagnetic material, thanks to the presence of the charge of filling with iron filings or other substances having similar characteristics, cause a periodic variation of the magnetic flux and, therefore, the generation by the sensor 21 of a periodic pulse signal having a frequency proportional to the number of teeth and spaces which pass through a unit of time in front of it, or rather, at the speed of rotation of the wheel 2; this signal can be used next,

  for example, in an ABS system of known type, not shown

  felt for simplicity, by comparing it with analogous signals coming from similar sensors which cooperate with other bearings identical to bearing 1 and supporting the other wheels of the vehicle to determine the appearance of abnormal differential variations in the speed of these and therefore to control, in a known manner, and which is therefore not described for simplicity, for example, suitable valves in the circuit

vehicle braking.

  To produce the bearing 1, a known method is followed except for the formation, on the annular groove 12 at the end 20, for example by removing material or,

  more simply, directly in the forming step pro-

  combining the outer ring 3 which is known, and not shown

  feel for simplicity; then a fluid paste 13

  having a high viscosity is prepared, this present

  both substantially pseudoplastic or similar behavior

  laire, and is cast or molded, preferably by injection, in the groove 12, for example, by means of a

  injector 30 (Figure 1); dough 13 can be made se-

  lon the invention by uniformly dispersing in a fluid matrix consisting of a resin or a mixture of resins

  partially polymerized synthetic material, a char-

  filling age consisting of a ferromagnetic substance

  such as magnetite powder, iron filings or the like; this mixture constitutes the dough

  13 which, by the action of heat and / or the addition of

  polymerizing tances such as activators and / or

  other monomers or polymers capable of reacting chemically

  only with the matrix, causes hardening once deposited in the groove 12, thus becoming solid, for example by the effect of a three-dimensional crosslinker; before this solidification takes place or is complete, the still fluid paste introduced into the groove 12 by the injector 30 is worked, according to the invention, in a plastic way by means of a forming tool

  by a toothed pinion 31 which rotates around its axis of sy-

  metry and simultaneously is moved at constant speed along the groove 12, facing it (Figure 1) so that its teeth 33 pressurize in the plastic mass formed by the dough 13 by forming the

  spaces 18 and simultaneously forming a corresponding tooth

  laying 16 between each pair of spaces 18 which are formed; excess dough 13 is pushed back from groove 12

  and collected, for example by means of a hopper not shown

  smelled. When all of the dough 13 deposited in the groove 12 has been worked, the dough 13 is allowed to solidify so as to finally obtain, by its hardening, the toothed ring 14. The latter, because of the way in which it has been obtained, and because of the superficial chemical-physical bonds that can form between the resin after polymerization and the material, usually steel, of the outer ring 3, is substantially anchored in the ring 3 itself ; this anchoring can be improved, if desired, by forming, in the groove 12, roughness of the knurling, teeth or similar shoulders which are then embedded in the dough 13 during the molding thereof so that they remain incorporated in the toothed ring 14. The preparation of the paste 13 does not raise any problem and any person skilled in the art of polymers can produce hundreds of different formulations, all equally effective for the purpose of the present invention, so

  that for the sake of simplicity we will not enter here into the

  rite of its specific composition; however,

  it is obvious that any known epoxy resin is parti-

  specially adapted to the desired goal, as are all the other room temperature thermosetting resins of the two-component type available on the market.

  The advantages associated with the bearing according to the invention appear

  arise from the previous description; in substance

  this, it incorporates the sonic wheel inside the outer ring so that a considerable reduction in dimensions and a notable ease of assembly are obtained compared to the assemblies used hitherto constituted by

  the bearing and the sonic wheel mounted so as to make sail-

  binds in relation to him; a considerable reduction in weight is also obtained because a metallic component (the wheel

  sonic) is' eliminated and a groove is formed, which re-

  reduces the weight of the outer ring 3, this reduction not being offset by the weight of the dough 13 which, being

  predominantly made of plastic material

  feels a low density compared to metal. Finally, the bearing 1 can be obtained in a simple, rapid and economical manner thanks to the arrangements for the production of the toothed ring by the plastic working of a paste which is then hardened. This arrangement also makes it possible to obtain considerable manufacturing precision. Finally, it is clear that the invention can also be applied to bearings intended to cooperate with sensors other than electromagnetic sensors, for example sensors

Z614955

  optics, provided that they are capable of being actuated by the passage of a succession of peaks and troughs such as those defined by the toothed ring 14; in this case the paste 13 can also be prepared without a filling charge, in particular with a ferromagnetic charge, and it could simply consist of a wax softened by heat 1'0

Claims (7)

  l.Bearing (1) for supporting a rotating member, in particular for a wheel (2) of a vehicle, characterized in that a ring (3) of said bearing, which can be   directly connected for rotation with said ro-   tation (2), is provided externally with an annular groove (12) at least partially filled with a solid substance (13); said solid substance (13) having been formed inside said annular groove substantially in   shape of a toothed ring (14) so as to define, parallel-   ment to a bottom wall (15) of said annular groove (12) and on the opposite side thereof, inside said annular groove (12) a plurality of peaks (16) and   hollow (18) having a regular succession.   2. Stair according to claim 1, characterized in that said solid substance (13) disposed inside said annular groove (12) consists of a solidified paste comprising a resin matrix   polymerized plastic in which is uniformly distributed   persée a filler of ferromagnetic substance-   than, for example, iron filings.   3-bearing according to one of claims 1 or 2, ca-   characterized by the fact that said annular groove (12) is   formed frontally on one end (20) of a ring ex-   inside of the bearing (3) opposite to that on which said   rotation member can be mounted.   4. Stair according to claim 2, characterized in that said end (20) of said outer ring (3) of the bearing which carries said annular groove (12), also comprises a radial- outer flange (22), said groove   (12) being formed frontally in said flange (22).   5. Method for obtaining a support bearing (1) for a   rotation member (2) capable of allowing detection   tion of the angular velocity of said organ by means of a   sensor (21), for example an electromagnetic sensor,   characterized by the fact that it comprises the following stages: it -forming an external annular groove (12) on a   ring (3) of said bearing (1) which can be connected for the ro-   tation with said rotation member (2); - pouring a fluid substance (13) in a pasty state into said annular groove; plastically working said fluid substance inside said annular groove so as to form in the fluid substance a regular succession of peaks and valleys; and - allowing said fluid substance (13) to harden to   the interior of said groove (12) after having worked it   lée, so as to form therewith a ring (14)   substantially toothed inside said groove (12).   6. Method according to claim 5, characterized in that the said fluid substance (13) in the pasty state comprises a matrix of synthetic polymer resin and a   filling charge consisting of a ferroma-   genetics which is uniformly dispersed throughout said matrix.   7. Method according to one of claims 5 or   6, characterized by the fact that said plas-   tick of said substance (13) molded inside the   said annular groove (12) is produced by means of a forming tool (31) which has the shape of a toothed pinion which is rotated around its axis of symmetry and which is   simultaneously moves along said front groove (12) very much to it.