FR2582760A1 - Constant velocity universal joint for motor vehicles - Google Patents

Abstract

Constant velocity universal joint for motor vehicles, comprising a male member such as a tripod which can be rotationally driven by a driving shaft, on each of the arms of which tripod there is mounted a rolling element interacting with raceways made in a barrel which is rotationally secured to a driven shaft, expansible elastic bearing bushes 4 being interposed between the arms 3 and the rolling elements; each bearing bush is formed of two semi-cylindrical half bushes 4 equipped with means 6 for axial and rotational secure fastening to the arm 3, in which arm there is made a radial hole 2 in which the hooking edge 6 of the half bearing bush 4 is clipped, this hole 2 being capable of receiving two curved-over edges 6 of two half bearing bushes 4 mounted on one and the same arm 3. These bearing bushes exert a progressive radial preload, which is not proportional to their radial curvatures and thus make it possible to obtain a maximum preload for an already significant radial displacement.

Description

The subject of the present invention is a constant velocity transmission joint, intended in particular for front-wheel drive motor vehicles.
This transmission joint is of the type comprising a male member capable of being rotated by a driving shaft and provided with radial arms, for example three in number forming a tripod, on each of which is mounted a rolling element trapped in a pair of raceways formed in a female member or barrel, integral in rotation with a driven shaft. Each rolling element being constituted by two separate sectors each cooperating with a rolling path, expandable elastic bearings are interposed between the radial arms and the rolling elements.

French patent 82 06 768 filed on 20
April 1982 describes a transmission joint of this type, in which the sectors constitute segments of rollers sliding or rolling on half-bearings in thin elastic plates, the curvature of which is different from that of the arm or journal of the tripod and the internal radius of the segment.

 French patent application No. 85 OS 882 of April 18, 1985 in the name of the Applicant also describes bearings constituted by expandable sockets interposed between the arms of the tripod and the bearing sectors.

 The purpose of these accessories is to absorb the mechanical play between the active articulation members of the constant velocity joint, while maintaining an elastic preload between the rolling and sliding members and the associated active rolling or sliding surfaces.

 However, this preload must be directed in a preferred direction and remain of a sufficient value even when the absorbed deflection is relatively large. Furthermore, the variable elastic stresses must remain relatively low, in order to ensure good reliability by avoiding fatigue breaks.

 The object of the invention is to propose an elastic pad exerting a progressive radial preload, that is to say not proportional to its radial deflection, and therefore to obtain the maximum preload for an already significant radial displacement.

 A second object of the invention is to have a much greater elastic work than with the devices mentioned above, -for a relatively modest material stress, which allows excellent reliability of the bearing to be obtained. .

In addition to its function of absorbing mechanical play, this bearing also has the function of presenting an external sliding or rolling surface for the load transfer members, that is to say the rolling sectors in a joint having the structure described in the aforementioned French patents.

 In accordance with the invention, each bearing is formed by two semi-cylindrical half-bearings and equipped with means for axial connection and in rotation with the associated arm, in which are provided complementary means capable of cooperating with said connection means, these half-pads which can expand radially by pinching between their ends of the arm on which they are mounted.

 According to a first embodiment of the invention, each half-pad is provided with a curved end edge adapted to snap into a hole formed radially in the corresponding arm, this curved edge ensuring the axial and rotational attachment of the half-bearing with the arm, while its free end applies to the arm a radial force tending to take off the half-bearing to place it in a relaxed position on the pitcher, the hole of the latter being adapted to receive preferably the two curved edges for attaching the half-pads associated with the arms.

 These half-bearings can have a thickness greater than that of the bearings of the state of the prior art recalled above, and therefore make it possible to store greater elastic energy for the same maximum stress in a given material, or even reduce the stress rate of the material at equal energy.

 According to a second embodiment, the complementary means comprise an axis radially traversing each arm and the ends of which project from this arm over a distance less than the thickness of the half-bearings, and the terminal parts of the latter have notches in which are housed the ends of the axis when the half-bearings are in the compressed position on the arm.

Other features and advantages of the invention will become apparent during the description which follows, given with reference to the appended drawings which illustrate a certain number of nonlimiting exemplary embodiments.
- Figure 1 is an axial sectional view of a transmission joint which can be fitted with bearings according to the invention, the joint being shown aligned;
Figure 2 is a cross-sectional view along II-II of Figure 1;
- Figure 3 is a cross-sectional view of a radial arm that can be part of the tripod joint illustrated in Figures 1 and 2, equipped with a half-bearing according to a first embodiment, the rolling element associated with this arms not shown;
- Figure 4 is an elevational view with partial section of the half-bearing of Figure 3 ;;
- Figure 5 is a view similar to Figure 3 of a second embodiment of the half-bearings associated with an arm of the male drive member;
- Figure 6 is a sectional view along
VI-VI of Figure 5;
- Figure 6A is a side elevational view of an end portion of a half-pad of the
Figures 5 and 6;
- Figure 6B is a front elevational view of an end portion of a half-frame of Figures 5 and 6;
- Figures 6C and 6D are respectively sectional views along VI-C-VI-C and VI-D-VI-D of the
Figure 6B;
- Figure 7 is a cross-sectional view of a third embodiment of the half-bearings according to the invention and of the arm on which they are mounted;
- Figure 8 is a view along VIII-VIIi of Figure 7 ;;
- Figure 9 is a cross-sectional view of an arm equipped with a half-pad according to an alternative embodiment of Figures 7 and S;
- Figure 10 is a side elevational view of the embodiment of Figure 9 with cross section of the half-bearings;
Figure 11 is a partial axial sectional view along XI of Figure 9;
- Figure 12 is a diagram illustrating the variation of the radial force exerted by a half-cushion according to Figures 3 and 4 on the associated arm as a function of the arrow;
- Figure 13 is an elevational view of a fifth embodiment of the pads according to the invention, taken along the axis of the tripod with section of the drive arm thereof;
- Figure 14 is a top view of the tripod of Figure 13 with cross section of the central arm; ;
- Figures 15 and 16 are elevation views in two perpendicular directions of a sixth embodiment of a half-pad according to the invention;
- Figures 17 and 18 are respectively a top view and a side elevational view of a seventh embodiment of the half-pad according to the invention;
- Figure 19 is a top plan view of an eighth embodiment of the half-cousin according to the invention;
- Figure 20 is a cross-sectional view of a radial arm equipped with two half-bearings according to Figure 19;
- Figure 21 is a side elevational view along arrow K of Figure 20;
- Figure 22 is a top view of an alternative embodiment of the embodiment of Figures 19 to 21 ;;
- Figure 23 is an elevational view of two omplémentaires half-pads according to a ninth embodiment of the invention;
- Figure 24 is a cross-sectional view of an arm equipped with the two pads of the
Figure 23;
- Figure 25 is an axial sectional view along XXV-XXV of Figure 24;
- Figure 26 is a side elevational view of a tenth embodiment of the half-pads according to the invention;
- Figure 27 is a partial axial sectional view of an arm fitted with half-bearings according to the
Figure 26;
- Figure 28 is a cross-sectional view of an arm along XXVIII - XXVIII of Figure 26 ;;
- Figure 29 is a cross-sectional view along XXIX-XXIX of Figure 30 of an eleventh embodiment of the invention
- Figure 30 is an axial sectional view along XXX-XXX of Figure 29;
- Figure 31 is an axial sectional view along XXXI-XXXI of Figure 32 of an arm equipped with a pad according to a twelfth embodiment of the invention;
- Figure 32 is a top view of the embodiment of Figure 31;
- Figure 33 is a top view of two half-bearings according to a thirteenth embodiment of the invention in the compressed position;
- Figure 34 is a cross-sectional view along XXXIV-XXXIV of Figure 33;
- Figure 35 is a side elevational view on an enlarged scale of a half-pad of the
Figures 33 and 34 ;;
- Figures 36 and 37 are views analogous to Figure 33 of two alternative embodiments;
The general structure of the constant velocity transmission joint shown in Figures 1 and 2 is described in the aforementioned French patent, so that this desc-ription will not be repeated here in detail.

 It will only be indicated that this joint is of the "fixed" type, that is to say non-telescopic, connecting a shaft 2.1 which can be part of a transmission for a motor vehicle with front-wheel drive, to a shaft 3.1 which can constitute a rocket of driving and steering front wheel.

 This seal comprises a male member consisting of a tripod 4.1 capable of being driven in rotation by the shaft 2.1, and provided with three radial arms 5.1 on each of which is mounted a rolling element, each element itself being constituted by two separate sectors 8A, 8B arranged on the opposite sides of the corresponding arm 5.1. The sectors 8A, 8B are trapped in pairs of rolling tracks 9.1 formed in a female member consisting of a barrel 110 integral in rotation with the driven shaft 3.1.

 Expandable elastic bearings 120 are interposed between the arms 5.1 and the sectors 8A 8B, in order to absorb the mechanical play between the arms 5.1 and the rolling sectors 8A, 8B.

 According to the invention, each bearing is formed by two semi-cylindrical half-bearings, equipped with means for axial connection and in rotation with the associated arm. in which are provided complementary means capable of cooperating with said securing means.

First embodiment <Fiaures 3 and A)
Each elastic half-pad 4 is provided with a curved end edge 6 adapted to snap into a hole 2 formed radially in the corresponding arm or journal 3. This hole 2 is dimensioned to receive the two attachment edges 6 of the two similar semi-cylindrical half-bearings 4 mounted on the arm 3, the hole 2 being drilled coaxially with the axis OX of the drive shaft 1 of the joint. Each rim 6 therefore ensures the axial and rotating connection of the corresponding half-pad with the arm 3, while its free end 4a applies to the arm 3 a radial force F which tends to remove 18 half-pads 4 to do so move from its position shown in solid lines to relaxed position 5 shown in dashed lines. In the position shown in solid lines, it is compressed and pressed against the surface of the arm 3 which receives the payload P in the direction OY. In the relaxed position 5, the half-cushion absorbs the play and presents with respect to its position compressed 4, an arrow s in the direction OY, this arrow v being exaggerated for the clarity of the drawing.
The curved edge 6, which can extend for example over a quarter of a circle as in the example illustrated in Figures 3 and 4, being engaged in the hole 2, the radial force F has a component P in the direction OY, of which the value is as follows if we neglect the friction
- half-pad 4 in maximum compressed position P2 = 2F2 sin
- half pad 5 bare: p 1-2F1 sin
It appears that F1 is less than F2, because the half-pad 4 has closed with a differential diametrical arrow f between the two positions considered 4 and 5. The angle of action of F1 being greater than the angle 2 for F2, it follows that the maximum of P is not obtained for the fully compressed position, as is the case in the elastic pads described in patent application No. 85 05 882 of April 18, 1985.

 Furthermore, it appears that the useful arrow a is worth several times the elastic arrow f.

This feature makes it possible to use thicker pads, and therefore to store greater elastic energy for the same maximum stress in a given material, or even at equal energy to reduce the stress rate of the material as already indicated above.

 flca comparison with the prior art is illustrated by the diagram in FIG. 12 for the same maximum stress and for the same diameter of the arm or journal 3. This diagram represents the useful radial force P perpendicular to the shaft 1 of the joint as a function of the radial arrow has the same direction for an elastic pad of known type (straight line D1) and for the pad according to the invention (straight line D2), by way of indicative numerical example.

 The second half-bearing 4, not shown in Figure 1, is mounted symmetrically to the first relative to the axis OX. The two end surfaces 7 located on either side of the curved edge 6 come opposite and bear against the corresponding surfaces 7 of the complementary half-pad 4. In total compression, there should remain a slight clearance between the free ends 10 of the two half-bearings 4.

Second embodiment (Figures 5 and 6, 6A-6D)
In this embodiment, the aforementioned securing means comprise, at each of the two ends of the half-bearings 11, a curved edge in the form of a cylindrical segment 12 formed on a tongue 14 cut at half-width 15 in the end part of the half-pad 16. The segments 12 are adapted to come to bear on the internal wall of two corresponding holes 13 arranged in the arm 11, when the half-bearings 16 are in the compressed position on the latter.

 The cylindrical segments 12 or "tom edged edges stop the rotation of the bearings 16 relative to the pin 11 by imparting a tangential compression in the tongues 14. The bearing 16 is shown in the relaxed free position. The bearing 17, partially shown on the right of the FIG. 5 is in the maximum compressed position, its end segment 12 coming to bear against the internal wall of the hole 13.

Third embodiment (Fiaures 7 and li
In this embodiment, an axis 19 force fitted, radially crosses each arm 18, and its ends project from the surface of this arm for a distance less than the thickness of the half-bearings 70. The terminal parts of the latter have notches 21, semi-circular in this example, in which the ends 20 of the axis 19 are housed when the half-bearings 70 are in the compressed position on the arm 18, shown in solid lines in FIGS. 7 and 8. The semi-circular shape of the notches 21 allows them to cover the ends 20 of the cylindrical axis 19, while the notches 21 are released from the ends 20 when the half-bearings 70 are released radially, to come to take the positions 21a shown in dashed lines in Figure 8.

Fourth embodiment (Figures 9 and
In this variant of the realization of
Figures 7 and 8, the ends of the axis 22 each have two flats 23 extending radially and along which can slide two fingers 24 of each end portion of a half-pad 71. Two contiguous fingers 24 are separated by a notch 25 with semi-circular bottom 26 of the same radius as the axis 22, and on which a corresponding sector of the axis 22, arranged between the two flats 23, is applied. When the half-bearings 71 are relaxed, the fingers 24 come to assume the position 24a.

 The axial guidance of the bearings 71 is ensured by the sliding of the flats 23 on the surfaces facing the notch 25, the fingers 24 conforming to the end of the axis 22 when the half-bearing 71 is compressed.

Fifth embodiment (Figures 13 and lii
The retention of the half-bearings 30 on the arms 28 integral with the shaft 27 is here ensured by their junction two by two. The half-bearings 30 of two consecutive arms 28 are thus paired by means of bridges 29, narrow enough not to interfere with the segments or rollers sliding on the external surface of these bearings 30.

 The double pad 72 (consisting of two half-pads 30) is shown in the free position, while the pad 31 is shown in the compressed position on the two pins 28, 32. The double pad 33 is shown with its left part (Figure 13 ) in cross-section in the compressed position on the pin 32, and relaxed by its right half-pad 30 on the pin 34.

 This embodiment has the advantage of being able to be mounted in a simple manner, does not require machining of holes in the pins 28, 32, 34, and can be carried out with a smaller number of parts than the previous ones.

 All the half-bearings described above are preferably made of hardened steel, and have a hardness of external surface suitable for sliding. This outer surface can be surface hardened by a thermochemical treatment, such as carbonitriding, followed by quenching, or be coated with a layer of anti-friction material, for example "Nylon".

Sixth embodiment (Fiaures 15 and 16)
The half-pad 73 is here similar to that of FIGS. 3 and 4, but the hooking flange 6 is replaced by a pin 35, preferably semi-cylindrical, welded at 36 to one end of the half-ring 73. The pin 35 is suitable to be received in a cylindrical radial hole 38, machined in the arm (not shown) of the tripod. The same hole 38 can receive two complementary pins 35 whose surfaces are applied to the cylindrical surface of the hole 38.

Seventh embodiment (Fiaures 17 and 18)
One end 39 of each semi-cylindrical half-pad 74 forms a bent rim at right angles, adapted to engage in a corresponding slot 40 machined in the arm, and whose width is slightly greater than the thickness of the bent rim 39 , so as to allow the expansion of the half-cushion 74 and its mounting. Slots 41 are cut in the rim 39 symmetrically with respect to the median plane of the half-pad 74, in order to allow the insertion in the same slot 40 of the crenellated edge 39 of the second complementary half-pad 14 mounted on the same arm.

 This embodiment has the important advantage of stabilizing the half-bearings 74 by preventing them from any possibility of rotation about the axis OX.

Eighth embodiment (Fi-aures 19 to 21)
Each half-pad 75 has one end 42 curved over at least the largest part of the width of the half-pad, and the arm 77 has an axial slot 43 wide enough to contain two overlapping curved edges 42 belonging to two half-pads 75 associated with the same arm 77. The slot 43 can be terminated at its ends by semi-circumferences 43a which ensure the axial retention of the curved edges 42, the latter possibly having a small clearance angle allowing assembly and expansion (position in lines mixed referenced 75a) of the half-bearings 75.

 The variant of FIG. 22 differs from that of FIGS. 19 to 21 by the fact that the bent end flange 44 of the half-pad 76 engages in an axial slot 43b, the bottom of which is cylindrical, of radius R, machined in the pin by a cylindrical cutter of the same radius. As a complement, the bent edge 44 carries at its two ends chamfers 45 able to come to rest support against the cylindrical bottom of the slot 43b.

 The half-bearings 75, 76 can also be mounted on an arm in which two slots are machined at the ends of the same diameter. Each of the two slots then has a thickness that is half the thickness, so as to index each only one of the two half-bearings mounted head to tail on the arm.

 Ninth embodiment (Figures 23.

25)
Each half-bearing 46 has, at one of its ends, a pair of lugs 47, preferably semi-cylindrical, obtained by bending at right angles and cold stamping of one end of the half-bearing. The lugs .47 facing the two complementary half-bearings 46 associated with an arm 50 are housed two by two in two holes 49 machined radially in the arm 50, FIG. 24 showing two half-bearings 46 in position compressed.

 This embodiment ensures good stability of the half-bearings 46, with efficient indexing and easy machining.

Tenth embodiment (Figures 26 to 28l
Three half-pads 51 each associated with a different arm 80 are connected together by a junction 52 with three branches 52a, a first set of three pads 51, shown in solid lines, being associated with a second set of three pads 53 shown in lines mixed, to style the arms of a tripod. The central zone 54 of the junction of this second set of half-bearings 53 is silken (FIG. 27) to allow passage to the central zone 55 of the junction 52 of the first set 51.

 The three integral half-bearings 51 to 53 are compressed together when the torque F is applied in the opposite direction of rotation to that of the needles of a watch (Figure 26). During the compression of the half-bearings, there is not exactly radial translation of these, but rotation around the point 0, trace of the axis of the shaft 56 of the constant velocity joint.

 This embodiment has the advantage of requiring only a reduced number of parts, and avoids the machining of the indexing means of the other embodiments described.

Eleventh embodiment (Fiaures 29 and 30)
This variant includes an improvement applicable to all of the embodiments described in the present application.

 A helical spring 57 is housed in a bore 58 passing radially through the arm 59 of the tripod, and exerts on the two half-bearings 60 a compressive force providing them with a radial expansion preload.

 this variant is advantageous in the case where the material constituting the pads has an insufficient elastic characteristic to allow expansion with a deflection and sufficient residual force. The spring 57 is shown in Figure 29 while the pads 60 are in the maximum expansion position. However, the spring 57 has a significant residual compressive force applied to the two half-bearings 60, which allows them to retain the necessary radial expansion recharge.

 Special bearings of the bimetal type with composite sliding surface are generally made of unhardened steel, and therefore with a low elastic limit. These pads constitute a special case where an additional elastic reserve is necessary, and where this additional reserve can be provided by a spring such as 57.

Twelfth embodiment (flowers 31 and 32)
The two half-bearings 78 associated with the same arm 64 are here produced in one piece 61 by virtue of a central connecting wall 62 housed in a diametrical slot 63 machined in the arm 64. Dishes 79 may be provided at the ends of the slot 63 to make room for the passage of the folding radius 66 between the central wall 62 and the cylindrical half-bearings 78.

 The bending of the central wall 62 is added to the form of closure of the half-pads 78 to ensure the arrows and the radial expansion forces sought.

Thirteenth embodiment (Fiaures 33 to 221
Figures 33 to 37 show three variants of an embodiment of the invention in which the half-bearings are particularly suitable for serving as inner raceways for needles.

 In the embodiment of FIGS. 33 to 35, the free ends of the half-bearings 83 have complementary male and female cutouts in the form of tenons 84 and mortises 85 5 ′ interpenetrating and guided laterally, in order to ensure a support continuity to the needles in the expanded position of the half-bearings 83. On the other hand a spring 92 is housed in a diametrical bore of each arm 91, and exerts a compressive force on the two half-bearings 83, ensuring them a radial expansion preload, the tenon 84 and the mortise 85 being shown in the compressed position.

 The free ends 93 of the half-bearings 83 have internal dishes 94 (FIG. 35) allowing the free expansion of the half-bearings on the corresponding arms by rotation around the rounded edge 95 of the indexing slot 90.

 Figure 36 shows half-bearings 98 provided respectively with a tenon 96 and a conjugate mortise 97 according to a variant of Figure 33, while Figure 37 shows a variant in which the half-bearings 88 associated with the same arms are respectively provided with a triangular tenon 86 and a triangular complementary mortise 87, the half-bearings 88 being shown in the expanded position.

 In each of these alternative embodiments, the half-bearings such as 83 include an end portion 89 for hooking, fitted into a slot 90 machined in the arm 91 (FIG. 35).

 In all the embodiments described above, the radial expansion of the half-bearings is obtained by pinching between their ends of the cylindrical arm or journal on which they are mounted, pinching which is carried out even when there is a spring of make-up such as 57 (Figure 29) or 92 (Figure 34).

Claims (17)

 1 - CV joint, comprising a male member (4.1) capable of being rotated by a driving shaft (2.1) and provided with radial arms (5.1; 3.11 ...) on each of which is mounted an element bearing trapped in a pair of raceways (90) formed in a female member (110) integral in rotation with a driven shaft (3.1), expandable elastic bearings (120; 4, 16, ...) being interposed between the radial arms and the rolling elements and each rolling element consisting of two separate sectors (8A, 8B) each cooperating with a raceway, characterized in that each bearing is formed by two semi-cylindrical half-bearings (4; 11; 7a) and equipped with means (6; 12; 21) for axial and rotational securing with the associated arm (3, 11, 18) in which complementary means (2; 13; 19) are provided capable of cooperating with said securing means, these half-pads being able to expand radially nt by pinching between their ends of the arm (5, 1; 3, 11, ...) on which they are mounted.  2 - Joint according to claim 1, characterized in that each half-pad (4) is provided with a curved end edge (6) adapted to snap into a hole (2) formed radially in the corresponding arm (3 ), this curved edge (6) ensuring the axial and rotational attachment of the half-pad (4) with the arm (3), while its free end (4a) applies to the arm a radial force (F) tending to remove the half-pad (4) to place it in a relaxed position on the arm, the hole (2) of the latter being adapted to preferably receive the two curved edges (6) for hooking the half-pads (11) associated with the arm (3).  3 - Joint according to claim 1, characterized in that the aforementioned securing means comprise, at each of the two ends of the half-bearings (16), a curved edge in the form of a cylindrical segment (12) formed on a tongue (14) cut out in the end part of the half-pad (16), and these cylindrical segments (12) are adapted to come to bear on the internal wall of the corresponding holes (13) arranged in the arm (11), when the half-pads are in compressed position on the latter.  4 - Joint according to claim 1, characterized in that said complementary means comprise an axis (19) radially passing through each arm over a distance less than the thickness of the half-bearings (70), and the end parts of these have notches (21) in which are housed the ends of the axis (19) when the half-bearings (70) are in the compressed position on the edge.  5 - Joint according to claim 4, characterized in that the axis (19) is cylindrical and the notches (21) of the half-bearings are semi-circular to allow the half-bearings (70) to cover the ends of the axis (19).  6 - Joint according to claim 4, characterized in that the ends of the axis (22) each have two flats (23) along which can slide two fingers (24) of each terminal outlet of a half-pad (71 ), these two fingers being separated by a notch, the bottom (26) of which is semi-circular and is applied to a corresponding circular sector of the axis (22), arranged between the two flats (23).  7 - Joint according to claim 1, characterized in that the half-bearings (30) are paired two by two by means of bridges (29) each connecting two half-bearings mounted on two separate arms (28, 34; 28, 32 ; 32, 34).  8 Joint according to claim 1, characterized in that a pin (35) for securing with the associated arm is welded to one end of each half-bearing (73) and adapted to be housed in a corresponding hole in the arm, this pin ( 35) being for example semi-cylindrical.  9 - Joint according to claim 1, characterized in that one end of each half-pad forms a bent flange at a right angle (39) adapted to engage in a corresponding slot (40) of the arm, and slots ( 41) are arranged in this rim symmetrically with respect to the median plane of the half-bearing (74) in order to allow the insertion in the same slot (40) of the crenellated edge (39) of the second half-bearing mounted on the same arm.  10 - Joint according to claim 1, characterized in that one end (42) of each half-bearing (76) is curved over at least the greatest part of the width of the latter, and the arm (77) has an axial slot (43) wide enough to contain two curved edges (42) superimposed belonging to two half-pads (75), the slot (43) may have terminal half-circumferences (43a) which ensure the axial retention of the curved edges (42) .  11 - Joint according to claim t, characterized in that one end of each half-pad (76) is constituted by a bent flange (44) engaging in an axial slot (43b) of the arm whose bottom is cylindrical , and this bent rim (4) has at its two ends chamfers (45) able to come to rest support against the cylindrical bottom of the slot (43b).  12 - Joint according to claim 1, characterized in that each half-bearing (46) comprises, at one of its ends, a pair of lugs (47) bent at right angles and the lugs (47) in vis- opposite two half-bearings (46) associated with an arm (50) are housed two by two in holes (49) formed radially in the arm.  13 - Joint according to claim 1, wherein the male member is a tripod carrying three arms (80), characterized in that three half-bearings (51, 53) each associated with a different arm (80) are connected together by a three-branch junction (52) (52a), the other three half-bearings being similarly connected, with a crimping of the central zone (54) of one of the junctions to allow passage to the central zone (55) of the other junction.  14 - Joint according to one of claims 1 to 13, characterized in that a spring (57) is housed in a bore (58) passing radially through each arm (59) and exerts a compressive force on the two half-bearings (60) mounted on the arm (59), providing them with a radial expansion preload.  15 - Joint according to claim 1, characterized in that the two half-bearings (78) associated with an arm (64) are made in one piece (61) with a central wall (62) connecting housed in a slot diametral machined (63) axially in the arm (64), dishes (79) can be provided at the ends of the slot to adapt to the folding (66) of the corresponding end parts of the half-bearings (78).  16 - Joint according to claims 1 and 14, wherein the bearings are particularly suitable for serving as inner raceways for needles, characterized in that the free ends of the half-bearings (83; 88,98) have male cutouts and complementary females, for example in the shape of a tenon (84,96) -mortaise (85,97) or triangles (86,87), ensuring continuity of support to the needles in the expanded position of the pads.  17 - Joint according to claim 16, characterized in that the free ends (93) of the half-bearings (83) have internal dishes (94) allowing the free expansion of the half-bearings.