FR2886693A1 - ANTI-ROTATION DEVICE FOR ROLLING BEARING, AND BEARING AND MACHINE THEREFOR - Google Patents

Abstract

Anti-rotation device for a bearing of the type provided with a rotating ring 2, a non-rotating ring 3, comprising an annular groove 8 formed on a cylindrical surface, and a row of rolling elements 4 arranged between paths of bearings of said rings, the bottom of said groove being eccentric with respect to the axis of the non-rotating ring, the device comprising an anti-rotation ring intended to be arranged in the groove.

Description

Anti-rotation device for rolling ring, and bearing and

associated machine.

  The present invention relates to the field of devices used to limit a possible rotation of a non-rotating race of a bearing relative to its housing. Such devices are generally called anti-rotation or anti-slip devices and are particularly used for bearings used in alternators.

  In this type of application, a rotor is rotatably mounted in a housing, inside which is fixed a stator, by means of two bearings of the type comprising a rotating inner ring, a non-rotating outer ring, and a row of rolling elements arranged between the rings. The inner rings of each of the bearings are mounted tightly on a bearing surface of the rotor, the outer rings being mounted in a housing of the housing provided for this purpose.

  The outer ring of one of the bearings is generally mounted in said housing with a sliding fit to allow a slight axial displacement of said ring relative to the housing.

  This adjustment can allow, on the one hand, to apply, via axially elastic washers, an axial prestressing force on the bearings, and, on the other hand, to overcome any axial dimensional variations of the housing due to thermal variations.

  In general, the outer rings of the bearings and their housings are made of materials of different types, for example steel and light alloy, such as aluminum. Due to the differential expansions of these two materials, the adjustment provided between the outer ring of a bearing and its housing can be modified, which can generate insufficient radial clamping between these two parts, or even a slight radial play.

  The internal friction torque of the bearing generated in particular by the viscosity of the lubricant used for said bearing, or by the friction of the bearing seals, combined with the decrease in the clamping or the slight play between the bearing and the housing , can cause angular sliding of the outer ring in its housing and adversely affect the proper functioning of the alternator. It is therefore necessary to provide devices for limiting a possible rotation of the outer ring relative to its housing.

  For this purpose, US Pat. No. 5,785,433 discloses an antirotation ring for an open race ring at a point of its circumference and defined radially by inner and outer curved and eccentric surfaces with respect to each other. . The ring comprises a plurality of elastically deformable portions.

  The ring is mounted inside a groove formed on an outer cylindrical surface of the outer ring of the bearing, said groove being provided with an eccentric bottom relative to the geometric axis of said ring. When mounting the bearing within a housing, the elastically deformable portions protruding from the outer cylindrical surface of the outer ring radially come into contact with said housing.

  In operation, during a rotation of the outer ring of the bearing relative to the housing, the ring remains stationary in the groove by frictional contact of the deformable portions with the housing, which causes a wedging between the outer ring, the ring and the housing thus limiting the angular displacement of the outer ring relative to said housing.

  Such a ring has the disadvantage of comprising a plurality of elastically deformable portions, which must be narrowed during assembly of the bearing inside the housing, which complicates a little the mounting operation of the bearing in its housing, and also creates a risk of particles being wrenched off the deformable portions of the ring if it is made of plastic material, thus potentially generating pollution risks.

  In addition, the ring has a relatively complex shape that can be expensive.

  Document JP-A-2000087988 also discloses an antirotation ring for a bearing ring mounted inside a housing, the ring being circumferentially continuous and mounted inside a groove formed on a surface cylindrical outer ring of the bearing. The groove is provided with an eccentric bottom relative to the geometric axis of said ring.

  The coefficients of friction between an outer annular surface of the ring and the housing within which the bearing is intended to be mounted, and between an inner annular surface of the ring and the bottom of the groove are adapted to allow the outer ring of the bearing to maintain, by friction, its angular position relative to the housing.

  The use of such a ring has the disadvantage of ensuring the angular immobilization in rotation of the bearing ring only by friction between two materials, which does not guarantee absolute positive locking.

  The present invention therefore aims to overcome these disadvantages by providing a anti-rotation device for reliable bearing, economical, and for easy mounting of the bearing.

  For this purpose, an anti-rotation device for a bearing is of the type provided with a rotating ring, a non-rotating ring comprising an annular groove formed on a cylindrical surface, and a row of rolling elements arranged between raceways of said rings, the bottom of said groove being eccentric with respect to the axis of the non-rotating ring.

  The device comprises a circumferentially continuous anti-rotation ring intended to be arranged in the groove. The ring is provided with at least one radially protruding tongue directed outwards and intended to be mounted inside a cavity formed in a housing inside which the non-rotating ring is mounted.

  Such a device has the advantage of comprising a tongue mounted in a shape matching recess for providing particularly accurately and securely locking rotational ring unwinding relative to the housing.

  In other words, since the non-rotating ring of the bearing and its housing are generally made of different materials, the ring maintains the angular positioning of said ring relative to the housing by friction, but also by blocking mechanical thanks to the tongue.

  In addition, with the existence of such a cavity, the tongue does not interfere when mounting the bearing inside its housing, which significantly simplifies the assembly of the machine inside which the bearing is mounted and increases its dependability.

  Preferably, the ring is made of synthetic material overmolded in the groove, which makes it possible to obtain a unitary assembly formed by the bearing and the anti-rotation device that can be handled and transported with risks of accidental separation of these elements. particularly weak.

  Advantageously, the radial thickness of the ring, outside the zone of the tongue, is variable according to the circumferential position considered.

  The radial thickness of the ring may be substantially equal to the depth of the groove, an outer surface of the ring being intended to be aligned radially with the cylindrical surface of the non-rotating ring.

  Such an arrangement thus makes it possible to limit any radial interference of the ring with the housing when the bearing is mounted inside said housing.

  Preferably, the ring has a substantially constant axial dimension.

  The ring may comprise a single tongue, so as to obtain a particularly economical device.

  Advantageously, the tongue and the ring are monobloc, which makes it possible to obtain a unitary piece.

  The invention also relates to a rolling bearing provided with a rotating ring, a non-rotating ring comprising an annular groove formed on a cylindrical surface, the bottom of said groove being eccentric with respect to the axis of the non-rotating ring. -turning, a row of rolling elements disposed between the raceways of said rings, and a circumferentially continuous anti-rotation ring and disposed in the groove.

  The ring comprises at least one radially protruding tongue directed outwards and intended to be mounted inside a cavity formed in a housing inside which the non-rotating ring is mounted.

  The invention also relates to a machine comprising a fixed part, a movable part, and at least one rolling device mounted between said parts and provided with a rotating ring, a non-rotating ring comprising an annular groove formed on a surface cylindrical, the bottom of said groove being eccentric with respect to the axis of the non-rotating ring, a row of rolling elements disposed between the raceways of said rings, and a circumferentially continuous anti-rotation ring and arranged in the groove.

  The ring comprises at least one radially protruding tongue directed outwards and mounted inside a cavity formed in a housing of the fixed part inside which the non-rotating ring is mounted.

  The present invention will be better understood on reading the detailed description of embodiments taken by way of non-limiting examples and illustrated by the accompanying drawings, in which: FIGS. 1 to 3 are perspective views of a bearing comprising an anti-rotation device according to one aspect of the invention; - Figure 4 is a schematic axial sectional view of the bearing of Figures 1 to 3; - Figure 5 is a schematic axial sectional view of the bearing of Figures 1 to 3 mounted on a shaft; - Figure 6 is a partial sectional view along the axis VI-VI of Figure 5; and FIGS. 7 to 9 are partial views of alternative embodiments of the anti-rotation device of FIGS. 1 to 6.

  As can be seen in Figures 1 to 5, the bearing, referenced 1 as a whole, is of the single row deep groove ball type. It comprises an inner ring 2, an outer ring 3, between which are housed a row of rolling elements 4 made here in the form of balls, a cage 5 for holding the circumferential space of the rolling elements 4, and two seals. sealing 6 and 7 metal.

  The inner ring 2 is massive type. Solid ring means a ring whose shape is obtained by machining with chip removal (turning and / or grinding) from tubes, bars, forged blanks and / or rolled. The inner ring 2 comprises a bore 2a of cylindrical shape delimited by opposite radial lateral surfaces 2b and 2c, and an outer cylindrical surface 2d stepped from which is formed a toroidal circular groove 2e having in cross section a concave profile capable of forming a rolling path for the rolling elements 4, said groove being oriented outwards.

  The inner ring 2 also comprises, at the level of the outer cylindrical surface 2d and near the radial surfaces 2b and 2c, two annular grooves (not referenced) symmetrical to each other with respect to a plane passing through the center of the rolling elements 4.

  The outer ring 3, also of massive type, comprises an outer cylindrical surface 3a delimited by opposite radial lateral surfaces 3b and 3c, and a 3d stepped bore of generally cylindrical shape from which is formed a circular toroidal groove 3e having a cross-section a concave profile capable of forming a raceway for the rolling elements 4, said groove being oriented towards the inside.

  The outer ring 3 also comprises, at the bore 3d and near the radial surfaces 3b and 3c, two annular grooves (not referenced) symmetrical to each other with respect to a plane passing through the center of the rolling elements 4. Said grooves rings are radially opposite the annular grooves of the inner ring 2.

  Inside said grooves are mounted the seals 6 and 7. The seals 6 and 7 are thus arranged radially between the inner and outer rings 2, 3. The seal 6 is mounted axially between the rolling elements 4 and the radial surfaces 2b and 3b of the rings 2 and 3, the seal 7 being mounted axially between the rolling elements 4 and the radial surfaces 2c and 3c of said rings 2 and 3.

  The outer ring 3 also comprises an annular groove 8 formed at the outer cylindrical surface 3a and having, in cross section, a substantially rectangular profile. The groove 8 is here arranged axially substantially between the center of the rolling elements 4 and the radial surface 31) of the outer ring 3. The groove 8 is here with radial lateral faces and comprises a bottom wall 8a annular cylindrical and eccentric with respect to a geometric axis 9 of the outer ring 3. Alternatively, the lateral faces of the groove 8 may also be inclined with respect to a radial plane of the bearing 1.

  Said outer ring 3 is here non-rotating, the inner ring 2 being rotating. Of course, it is also conceivable to provide a rotating outer ring and a non-rotating inner ring.

  The bearing 1 also comprises an anti-rotation ring 10, advantageously made of synthetic material molded inside said groove 8. The ring 10 may for example be made of polyamide loaded or non-filled with glass fibers, or other additives.

  As illustrated more clearly in FIG. 6, the ring 10, made in one piece, is provided with a circumferentially continuous circular fastening portion 11 delimited radially by inner and outer cylindrical surfaces 1a and 1b, and an outgrowth or radial protrusion forming tab 12 and extending, in part, the outer surface 11b outwardly. The inner surface 1a is intended to be in radial contact with the bottom wall 8a of the groove 8.

  The circular fixing portion 11 has a variable radial dimension outside the area of the tongue 12. In other words, the inner and outer cylindrical surfaces 1a and 1b are eccentric with respect to each other.

  The circular portion 11 has a substantially constant axial dimension and corresponds to the axial dimension of the groove 8.

  The tongue 12 is disposed substantially at a median plane of the circular portion 11 and has a generally rectangular shape. The angular dimension of the tongue 12 is reduced relative to that of the circular portion 11, and is for example between 10 and 15. The axial dimension of the tongue 12 is substantially equal to that of the circular portion 11, its radial dimension being substantially greater than that of said portion 11.

  The ring 10 is overmolded in the groove 8 of the outer ring 3 of the bearing 1 so that the tongue 12 is centered in the zone of maximum depth of said groove 8, and the outer surface 11b of the ring is aligned radially. , outside the zone of the tongue 12, with the outer cylindrical surface 3a of the rolling ring 3.

  The bearing 1 is mounted on a shaft 13 of geometric axis 14 and inside a body 15. The geometric axis 14 and the axis 9 of the outer ring 3 are merged.

  The body 15, of generally annular shape, comprises a first radial portion 15a disposed in the vicinity of the outer cylindrical surface of the shaft 13 and extending outwards, which is extended, from an upper end, by a second radial portion 15b extending outwardly. The second radial portion 15b has an axial dimension substantially greater than that of the first portion 15a and forms a bearing surface for the radial surface 3b of the outer ring 3 of the bearing 1. The second radial portion 15b is extended, from an upper end, by an axial portion 15c provided with a bore 15d inside which is housed in contact the outer ring 3 of the bearing 1.

  The axial portion 15c of the body 15 also comprises a cavity 16 formed at the bore 15d, substantially in shape with the tongue 12 of the ring 10. The cavity 16 leaves a slight radial clearance 17 between an outer surface of the tongue 12 and the axial portion 15c of the body 15.

  In alternative embodiments, it is also conceivable to provide a cavity 16 having in cross section a generally triangular shape, the tongue 12 may for example be identical to that previously described (FIG. 7), or else in concordance with said cavity (Figure 8). It is also conceivable to provide, as shown in Figure 9, a cavity 16 having in cross section a profile in the form of a semicircle.

  To mount the bearing 1 inside the body 15, the inner ring 2 is firstly engaged on the shaft 13, then the shaft is mounted inside the body 15 so that the tongue 12 of the ring 10 is housed inside the cavity 16 of the axial portion 15c. During the introduction of the bearing 1 inside the axial portion 15c, the ring 10 does not interfere with the bore 15d, by design, the cylindrical portion 11 of the bearing of the ring 10 being radially at the same level as the outer cylindrical surface 3a of the outer ring 3 of the bearing.

  In operation, the outer ring 3 of the bearing 1 is immobilized angularly relative to the axial portion 15c of the body 15, by mechanical cooperation of the tongue 12 with the cavity 16 thus limiting a displacement of the outer ring 3 relative to the housing.

  In addition, in the case where the adhesion of the synthetic material molded ring 10 on the outer ring 3 of the bearing would not be large enough to ensure its angular attachment to said ring 3, if the outer ring 3 tends to rotate relative to the body 15, the ring 10, mounted in radial contact with the bore 15d of the body 15, remains angularly stationary thanks to the tongue 12, which causes, by a cam effect, a radial displacement of said ring 10 towards the of the bore of the cavity 16. The radial displacement of the ring 10 takes place until the outer surface 11b comes to bear against a portion of the bore 15d of the housing located on either side of the the cavity 16.

  The ring 10 is thus blocked radially between the bottom of the groove 8 and a portion of the bore 15d of the body 15, which causes an angular immobilization of the outer ring 3 of the bearing 1, by wedging between the ring 10 , the groove 8 and the bore 15d, and the mechanical locking of the tongue 12. The possible angular displacement of the outer ring 3 inside the body 15 is thus very limited, and the bearing ring is permanently locked.

  The ring thus performs, in operation, an antirotation system of a ring relative to its housing particularly effective, easy to assemble, reliable and economical.

Claims (9)

  1-Anti-rotation device for a bearing of the type provided with a rotating ring (2), a non-rotating ring (3) comprising an annular groove (8) formed on a cylindrical surface, and a row of rolling elements (4) arranged between bearing paths of said rings, the bottom of said groove being eccentric with respect to the axis of the non-rotating ring, the device comprising a circumferentially continuous anti-rotation ring (10) intended to be disposed in the groove, characterized in that the ring comprises at least one radially protruding tongue (12) directed towards the outside and intended to be mounted inside a cavity formed in a housing inside which the ring non-rotating is mounted.   2-Device according to claim 1, wherein the ring (10) is made of synthetic material overmolded in the groove (8).   3-Device according to claim 1 or 2, wherein the radial thickness of the ring (10), outside the zone of the tongue, is circumferentially variable.   4-Device according to any one of the preceding claims, wherein the radial thickness of the ring (10) is substantially equal to the depth of the groove, an outer surface of the ring being intended to be aligned radially with the cylindrical surface of the non-rotating ring.   5-Device according to any one of the preceding claims, wherein the ring (10) has a substantially constant axial dimension.   6-Device according to any one of the preceding claims, wherein the ring (10) comprises a single tongue (12).   7-Device according to any one of the preceding claims, wherein the tongue and the ring are monobloc.   8-rolling bearing provided with a rotating ring (2), a circumferential ring (3) comprising an annular groove (8) formed on a cylindrical surface, the bottom of said groove being eccentric with respect to the axis of the non-rotating ring, of a row of rolling elements (4) arranged between the rolling paths of said rings, and a circumferentially continuous anti-rotation ring (10) arranged in the groove, characterized in that ring comprises at least one radially protruding tongue (12) facing outwards and intended to be mounted inside a cavity formed in a housing inside which the non-rotating ring is mounted.   Machine comprising a fixed part, a movable part, and at least one rolling device mounted between said parts and provided with a rotating ring (2), a non-rotating ring (3) comprising an annular groove (8). ) formed on a cylindrical surface, the bottom of said groove being eccentric with respect to the axis of the non-rotating ring, of a row of rolling elements (4) arranged between the rolling paths of said rings, and of a circumferentially continuous anti-rotation ring (10) arranged in the groove, characterized in that the ring comprises at least one radially protruding tongue (12) directed outwards and mounted inside a cavity (16) formed in a housing of the fixed part inside which the non-rotating ring is mounted.