Axial rolling bearing for a suspension

0001The present invention relates to the field stops of suspension used in particular on motor vehicles in the telescopic struts of the steered wheels.

0002A suspension thrust bearing generally comprises a ring upper and a lower ring between which are arranged rolling elements in the form of balls or rollers.

0003The invention relates more particularly to the stops suspension arranged between a support element connected to the body of vehicle and a support element connected to a spring suspension.

0004In conventional manner, the suspension stop is arranged in the upper portion of the strut between a cup bottom, also serving as a bearing seat for a spring suspension, and an upper element of the vehicle. The spring suspension device is installed around the rod damper piston whose end is secured to a support block elastic. The bearing suspension stop allows a movement rotation between the cup spring support, mobile in rotation, and elastic support block which is attached to the vehicle. The abutment suspension also allows the transmission of axial forces between spring and the vehicle body. The relative angular movement between the bearing cup of the spring and the elastic support block results from a Turning the steering wheel and / or compression of the spring suspension. One can refer to the French document No. 2,779,096.

0005suspension thrust bearings are located under the body vehicle and near the wheels that project, especially in rainy weather, the contaminants likely enter the bearing and alter the long good operation.

0006of can be used in known manner, as in the documents US 4,995,737 or EP-A-390 331, a device using one or two plastic caps, each cap capping a ring and having axial retaining means cooperating with the other cap. The seal is then provided by the lips from one of the cowls and rubbing against each other cover. The covers are usually made plastic reinforced with glass fibers to impart the the necessary strength and rigidity. This material is too rigid to constitute a sufficiently effective seal. We can also envisage arranging seals by fitting on the rings of the bearing, but in this case they should be used with seals metal frame, which is relatively expensive to make, see JP 08-219 150.

0007French Patent 2,809,992 describes a sealed bearing for abutments suspension comprising a lower ring, a ring above, a row of rolling elements, a top cover synthetic material and a seal mounted on the hood top and provided with a lip coming to rub with the lower ring or with a lower bonnet secured to the lower ring. The seal is provided with a heel arranged and fixed in an annular groove of the cover. Positioning and handling of the gasket which does not include frame must be well controlled.

0008The present invention aims to ensure a good sealing of bearing and economical manufacture. In addition, the invention aims to ensuring high compactness and low weight of the hood.

0009The device of thrust bearing suspension, according to a aspect of the invention is of the type comprising a first ring, second ring, a row of rolling elements arranged between the two rings, a hood which is arranged in the first ring, and at least a seal fixed to the hood and adapted to cooperate with a Surface non-rotating or rotating respectively. garnish sealing comprises a connecting portion with the cap and a lip sealing. The seal is attached to the cover by a plurality of protrusions from the connecting portion and coming into projecting, at least partially, in at least one housing cover with which said protrusions cooperate to liaise axially between the cover and the seal. and it ensures excellent axial and circumferential attachment of the lining sealing on the hood, and prevents the intrusion of external elements thanks to the sealing lip. The cap may have a mass and a neighbors volume of those of working without hood lining sealing.

0010In one embodiment of the invention, the protrusions are axial.

0011In one embodiment of the invention, the gasket seal comprises two sealing lips so that is shut tight on the inside and the outside of the rolling. Alternatively, the seal comprises a single sealing lip, sealing the opposite side to the lip sealing can be ensured by other means.

0012In one embodiment of the invention, the gasket seal comprises a sealing lip directed towards the inside.

0013In one embodiment of the invention, the gasket seal comprises a sealing lip directed towards the outside.

0014In one embodiment of the invention, a lip sealing door on a bearing ring.

0015In one embodiment of the invention, a lip sealing door on a bearing cover.

0016Advantageously, the connecting portion is discontinuous circumferentially. Substantially radial grooves may be formed in the cover to accommodate the branches of the portion of link. The circumferential attachment between the liner sealing and the cap is ensured by both the protrusions and by the branches of the connecting portion.

0017Advantageously, the protuberances are distributed over at least two concentric circles.

0018In one embodiment of the invention, the protrusions have an axial cylindrical shape.

0019In one embodiment of the invention, the protrusions are shaped rivet.

0020Said protrusions may have a square section.

0021In one embodiment of the invention, the protrusions have an annular groove. The annular groove may cooperate with a cover retaining surface.

0022In one embodiment of the invention, the housing cover has an axial cylindrical shape.

0023In one embodiment of the invention, the housing cover has a substantially radial retention surface.

0024The cover may be made of polymer, for example in polyamide PA 6.6, which is 5% of glass fibers. garnish sealing can be made of a much softer material than the hood, for example an elastomer, eg an elastomer of the family of Elastollan® of BASF.

0025The bearing suspension stop is obtained extremely compact, the attachment portion of the seal being housed in grooves of the cover. The seal is perfectly maintained, both by pin-shaped protrusions that by the complementary shapes of the cover grooves and branches of the connecting portion of the seal, and also in that the bearing ring then comes to cover the seal which is axially sandwiched between said ring and the cover corresponding.

0026Advantageously, the gasket sealing lip can be used as axial retention means of the top cover on the hood lower, said lip from interfering with a radial bead of the skirt of the top cover in the event of axial distance between the two covers. This is especially useful when handling and transporting device since the untimely dismantling and concomitant losses avoided.

0027The invention also provides a process for manufacturing a seal and a cover, wherein the gasket is molded and sealing the cap in the same mold with several footprints molding, said mold comprising at least one rotating part, is brings the gasket and the cap in axial alignment in the mold, and assembling the seal and the cap by a axial movement of the mold parts.

0028cover is defined as a part in contact with a ring bearing and ensuring the recovery of stresses to the ring towards the least one other element.

0029The present invention will be better understood and other advantages apparent on reading the detailed description of some modes implementation given by way of non-limiting examples and illustrated by the accompanying drawings, in which:<ul><li>Figure 1 is an axial sectional view of a thrust bearing Suspension according to one aspect of the invention;</li><li>Figure 2 is a view in axial section of the liner sealing;</li><li>Figure 3 is an axial sectional view of the corresponding cover;</li><li>Figure 4 is a top view elevation of the packing sealing;</li><li>Figure 5 is a top view in elevation of the cap;</li><li>Figure 6 is a detail view of Figure 1;</li><li>Figure 7 is a view corresponding to Figure 6 in a plane angularly offset cuts;</li><li>Figure 8 is a detailed view of the housing provided in the cap;</li><li>Figure 9 is a bottom view of the housing formed in the cap; and</li><li>Figure 10 is a half-view in axial section of a cover and a seal according to another aspect of the invention; and</li><li>Figure 11 is an axial sectional half-view of a cover and a seal according to another aspect of the invention; </li><li>Figures 12 and 13 are corresponding to Figures 8 and 9 of another embodiment; and</li><li>Figure 14 shows the respective congestion in the free state pegs and holes 12 and 13 of FIGS.</li></ul>

0030A shock absorber comprises a cylinder in which is slidable a piston whose rod is connected by its upper end to a support block elastic one, which bears in a frame member A seat and is secured therewith.

0031The elastic support block 1 includes an upper cup 2 serving as a seat for supporting the thrust bearing 3, and a block rubber bonded to the surface of these three parts and realizing a bond therebetween with vibration damping.

00324 a suspension spring is supported on a lower cup 5 which, in turn, relies on the thrust bearing 3.

0033The upper cap 2 comprises a cylindrical portion 2a extending downwards, away from the chassis, and a radial portion 2b extending outwardly. The inner surface of the portion cylindrical 2a and the upper surface of the radial portion 2b are covered with the elastic material used in the support block 1 elastic.

0034Of course, this upper support structure for the abutment suspension can have many variations with or without cup. The stop can also come directly supported in a Higher seat formed or attached to the vehicle body.

0035The bump stop 3 comprises an upper ring 6, and a lower ring 7, both sheet metal between which are housed the balls 8. The bearing 8 are held by a cage 9 material synthetic. The lower ring 7 includes a toroidal portion 7a having a concave surface forming a raceway adapted the rolling elements 8 and a radial portion 7b extending toward within the toroidal portion 7a and located substantially at mid-height of rolling elements 8.

0036The thrust bearing 3 further comprises a top cover 10, synthetic material such as a polyamide reinforced fiber glass, covering the surface of the upper ring 6 opposite the rolling elements 8 and shaped corresponding to the surface outside the axial portion 2a and the lower surface of the portion radial 2b of the upper plate 2. The top cover 10 includes a substantially tubular skirt 11 extending downwardly from its edge of large diameter and radially surrounding at least partly the rolling elements 8.

0037The top cover 10 further comprises an inner skirt 12 extending downwards and having a cylindrical bore and a surface Outdoor provided with a circular flange 13 having a surface substantially radially oriented upwards. Between the outer skirts 11 and inner 12, the top cover 11 includes a rounded portion 14 adjacent to the outer skirt 12 shaped corresponding to the ring upper 6 and provided with ribs 15 on its convex surface. The ribs 15 are flush with the upper surface of the top cover 11 and are disposed slightly set back with respect to the outer surface of the outer skirt 11. The ribs 15 can increase locally the rigidity of the upper cover 10 close to the upper ring 6. The top cover 10 further includes an upper radial portion 16, extending inwardly from the rounded portion 14, and a oblique portion 17 arranged between the radial portion 16 and the skirt inner 12. Radial ribs 18 are also formed on the oblique portion 17 on the side opposite to the rolling elements 8, and possible to increase the rigidity of the top cover 10 and the surface contacting said top cover with its supporting seat 2.

0038In addition, as can be seen in Figure 1, the skirts 11 and 12 have a smaller thickness than the curved portions 14, 16 radial and oblique 17, which allows a mass reasonable for the cover 10 with a high rigidity in the portions subjected to high mechanical stress. The cover 10 is in Direct contact with the upper ring 6 on one side and with Headquarters Higher support 2 on the opposite side.

0039It is further provided a lower cover ring 19 in shape corresponding to the lower plate 5 and the ring less than 7, and for transmitting axial forces between these elements. More specifically, the lower cover 19 comprises a body 20, of annular form, and an axial skirt 21, also of annular form, extending downward along the axial portion 5a of the cup less than 5 and in contact therewith, and having a annular lower end 22 provided with a plurality of tabs 23, distinct from each other, each occupying an angular sector determined and directed downward and outward, to present a diametrical interference with said axial portion 5a of the cup 5, and avoid a possible separation between said lower cover 19 and said lower retainer 5 before final installation.

0040The body 20 of the lower cover 19 has a lower surface radial ring 24 in contact with the upper surface of the portion radial 5b of the lower cap 5, an inner surface 25 separate annular radial surface 24 by the skirt 21, and a surface rounded upper concave 26, in concordance with the shape toroidal portion 7a of the lower ring 7 to serve as a bearing seat said lower ring 7. The body 20 therefore enables the transmission of axial forces against the lower plate 5 and the lower ring 7. The diameter of the imaginary circle passing through the center of the rolling elements 8 and the diameter of the imaginary circle passing through the end turn of the spring 4, are substantially equal, and the lower cap 5, the bottom cover 19 and the lower ring 7 have radial dimensions substantially equivalent, whereby the existing efforts in these elements are essentially axial forces, the efforts of torsion remaining very low, which will relieve the said structure parts concerned.

0041In addition, there is provided a seal member 27 made of flexible synthetic material, in particular elastomer, for example in Elastollan® from BASF arranged between the lower ring and 7 the lower cover 19.

0042The sealing member 27 includes an inner lip 28 annular, rubbing against a cylindrical outer surface of the inner skirt 12 of the top cover 10, an outer lip 29, annular, in frictional contact with the bore of the outer skirt 11 of the upper cover 10, a connecting portion 30, in concordance form with the lower surface of the lower ring 7 and having a plurality of radial branches of small width, arranged in radial grooves 33, concordant shape, formed in the surface concave top 26 of the body 20 of the lower cover 19, and a plurality of pegs 31 arranged on the lower surface of the portion of link 30, directed downwards, projecting in housing corresponding 32 formed in an axial direction in the body 20 the lower cover 19.

0043The connecting portion 30 ensures, on the one hand, the joining between the sealing lips 28 and 29, thereby achieve the seal in one piece, and, on the other hand, to ensure connection in rotation of the seal 27 and the lower cover 19, through the radial branches of the portion of link 30 cooperating with the radial edges of the grooves 33 of the body 20. The connecting portion is in contact with the toroidal portion 7a the lower ring 7. The radial portion 7b is disposed above the connecting portion 30 with a small axial space between these two rooms. Between the lip 28 and the toroidal portion 7a, the portion of link 30 includes a radial ring 30a.

0044As seen more particularly in Figures 2 and 3, the seal 27 is provided with a plurality of pegs 31 arranged in two concentric circles, the holes 32 formed in the body 20 also being divided into two groups along two concentric circles to cooperate with the pins 31. This ensures a close rotating connection of the sealing lip inner 28 to the inner pins and the sealing lip external 29 for external pins, thereby preventing a possible deformation of the seal 27. The pegs 31 are oriented towards the lower cup 5.

0045In addition, the pegs 31 also provide attachment axially between the seal 27 and the lower cover 19. pegs 31 have a generally cylindrical shape with one end Free slightly beveled or rounded. The holes 32 formed in the 20 bodies have a constriction 34 near the lower ring 7 provided with an oblique surface 34a near the lower ring 7, and a remote cylindrical portion 36 of the lower ring and 7 separated from the constriction 34 by a radial surface 35. The body 20 being made of substantially stiffer material than the liner seal 27, the pins 32 are deformed during assembly of the seal 27 on the bottom cover 19 to passage of said narrowing 34, then tend to resume a larger diameter after crossing the small narrowing of 34 and are then retained against disassembly by axial movement in opposite direction, tending to separate the seal 27 of the lower cover 19, by the radial surface 35.

0046As can be seen in Figures 5 and 6, the holes External fixation 32 of the body 20 are formed from the grooves 33, while 32 internal holes are formed outside said grooves 33. The pins 31 of the outer gasket 27 are supported by the radial legs of the connecting portion 30, then that the internal pins 31 are supported by the annular edge of the neighboring connecting portion of the inner lip 28.

0047In the embodiment illustrated in Figure 10, the surface 35 radial hole 32 is disposed relatively low and the pin 31 the assembled state then has a rivet head shape. Alternately, provision may be smooth, through holes 32, with fastening final of the seal by heat distortion the free end of the pins 31.

0048In addition, the seal 27 illustrated in Figure 10, comprises a circular flange 37 formed on an upper surface of the radial inner sealing lip 28 adapted to be pinched 7b between the inner radial portion of the lower ring 7 and the body 20 of the lower cover 19, which reduces the risk of veiling of the inner sealing lip 28.

0049It is also understood that in case of attempted separation axial top cover 10 the rest of the bearing, the bead circular 13 of the inner skirt 12 of top cover 10 has diametrically interfere with the inner sealing lip 28 of the seal 27, thereby preventing complete separation of top cover 10. As the seal 27 is secured axially from the bottom cover 19, through cooperation between the pawns 31 projecting the holes 32 and a unitary assembly is formed, comprising the top cover 10, the rings 6 and 7, the elements Roller cage 8 and 9, the seal 27, the cover bottom 19 and the lower cup 5.

0050In other words, the seal 27 ensures, in addition a sealing function, a function of axially retaining the cover with wherein said seal 27 is in static contact and cover with which said sealing gasket 27 is in contact friction.

0051The resulting assembly is extremely compact, since the fixing part of the seal is embedded in the lower cover. The seal is held securely by both pawns that by the form fit between the liner and the cover inferior.

0052Alternatively, one could predict that the lips trim come to bear on the surface of the bearing ring rotatable relative to said packing.

0053As illustrated in Figure 11, the rolling bearing 3 comprises an upper ring 6 provided with a toroidal portion 6a in contact with the rolling elements 8 and a radial portion 6b extending outwardly and a lower ring 7 provided with a toroidal portion 7a into contact with the rolling elements 8 and a radial portion 7b extending radially inwardly, the portions radial 6b and 7b being substantially at the same height in the direction axial.

0054The bottom cover 19 has no skirt and includes a radial bottom surface 24 and a toroidal surface 26 contacts with the corresponding toroidal portion 7a. A circular clearance 38 is formed on the upper edge of the inner side of the body 19, to close to the free end of the radial portion 7b of the ring less than 7 and is willing to short distance from the free end of the radial skirt 11 of the upper body 10 to form a seal by narrow passage. The outer side, the body 19 includes a lip 39 extending obliquely downwardly outwardly and adapted to interfere diametrically with the circular bulge 13 of the radial skirt outer 12 of the upper body 10 to prevent separation between the top 10 and bottom 19 caps.

0055The seal 27 comprises a lip 29 directed outwardly and rubbing against the lower surface of the portion radial 6b of the upper ring 6, an annular body 40, section transverse rectangular, arranged in a corresponding accommodation of the bottom cover 19 and a plurality of pins 31 facing down and arranged in a plurality of holes 32 opening out on the surface lower radial 24 of the lower cover 19.

0056In addition, the rolling bearing 3 comprises a further filling 41 supported by the upper sealing cover 10 and provided with a inner sealing lip 28 directed obliquely downwards frictional contact with the upper surface of the radial portion 7b of the lower ring 7, an annular body 42 arranged in a corresponding recess formed in the top cover 10 and which in cross section a generally rectangular shape, and a plurality of pins 43 projecting upwards in the axial holes 44 opening on the upper surface of top cover 10.

0057More specifically, the housing body 42 of the gasket seal 41 and the holes 44 are formed in the portion radial 16 of top cover 10. The sealing lips 28 and 29 in contact with the bearing rings surfaces ensure a excellent seal. This sealing is enhanced by entering narrow clearance 38 formed between the lower cover 19 and skirt inner 11 of the top cover 10 and through the narrow passage between the lip 39 of the bottom cover 19 and the annular flange 13 of the skirt 12 of top cover 10. The lip 39, made of the same material that the lower cover 19 and providing a higher rigidity than the seals 27 and 41 ensure, on the one hand, a sealing by narrow passage and, on the other hand, retained by interference diameter with the bead 13.

0058As illustrated in Figures 12 to 14, the fastening holes 32 external body 20 are formed from the grooves 33 and are cylindrical, circular and blind. The inner holes 32 can also be cylindrical, circular and blind. The pins 31 present in the free state a cylindrical shape of square section chamfered end. The diagonal of the square pegs 31 is greater than the diameter of the holes 32. The corners of the pegs 31 are crushed against the circular wall of the holes 32. The pins 31 to the state mounted in the holes 32 are tightened and deformed by the hole walls 32 which ensures the axial restraint between the cover and the gasket sealing. The end chamfer of the pins 31 facilitates insertion pegs 31 in the holes 32. Also, the small radial space remaining in places between a pawn and allows the corresponding hole air to escape during the sinking of the peg in the hole.

0059The entire lower cover and seal could advantageously be made on an injection molding machine using a method of assembly in the mold with a mold in two parts rotating means allowing the same mold to produce the molding and assembly of different pieces, both in terms of the geometry as the material, without the need for recovery of the parts. The mold comprises a fixed body provided with an eccentric core and a feeding material to be injected, a movable body provided with a core offset from the side opposite to the fixed core, a first rotating part disposed between the fixed body and the mobile body axis of rotation and translation parallel to the mold axis, and a second rotating part disposed between the stationary body and the first rotating part. of the diametrically opposed molding dies are provided in each rotating part, with funds sent respectively to the fixed body and the movable body. The rotating parts are provided for rotated 180 degrees to exchange their respective positions fingerprints. The supply of material to be injected is provided for supplying a first molding cavity eccentric nucleus fixed to molding a first part of the piece to be produced, and a second mold cavity at the mobile core for molding a Part of the room to achieve. support shafts and training is provided for moving the molded parts and to assemble. The molding takes place in the extreme positions of molding, then the molded parts are brought back towards the central position and assembled by an axial movement.

0060One can refer in this respect to EP B 1,060,868.

0061Part of the mold will achieve the hood. The other part of the mold will achieve the trim, the two parts then being assembled, with or without rivet head formation the end of checkers after axial opening, rotating parts Rotating the mold and re-closing of the mold, the hood assembly and of the gasket and, optionally forming rivet heads making when closing the mold. It enjoys a subset Hood / Economic seal, low mass and particularly compact thanks to the disposal of part of the seal between the ring and the corresponding cover.