FR2619607A1 - HOMOCINETIC JOINT AND METHOD FOR MANUFACTURING THE SAME - Google Patents

Abstract

The invention relates to a constant velocity universal joint. It relates to a seal whose outer and inner members 10, 11 have partially spherical surfaces in contact and ball housing grooves which diverge towards one end of the outer member which is closed by a closure member 17. balls 16 are retained in the grooves by an element 31 and a support member 32 which can pivot on the closure member 17, a spring device 36 acting between the member 31 and the support member 32 so that the balls are pushed into the grooves as far as possible. Application to homokinetic joints intended to rotate at high speed with low angles.

Description

The present invention relates to a homokinetic universal joint.

  A seal according to the invention is intended to be used

  when the necessary articulation angles are relatively small and essentially, although not

  exclusively, at high speeds of rotation. Like-

  the conditions exist in the case of universal joints incorporated in the drive or transmission shaft of a motor vehicle, that is to say the shaft arranged along the length of the vehicle between a motor assembly mounted at the front and a driven rear axle of the vehicle. The transmission shaft of the vehicle can rotate at the same speed as the engine and possibly even faster, and thus it can be considered that rotational speeds of the order of 6000 rpm and even more can be met. Likewise, the geometrical configuration of the drive shaft is usually such that the universal joints of the shaft do not have to have hinge angles exceeding

    about. However, universal joints according to the

  vention can be used not only in drive shafts but also in all applications

  in which the criteria laid down are similar or analogous

  logics, and even in lower speed applications

  when the necessary hinge angles are small.

  One condition that must be fulfilled by a constant velocity universal joint intended for use at very high speeds of rotation, for example in the case of the drive shaft of a vehicle, is that the seal must give

  a very high radial stability, that is to say that the

  The gantry leading or conducting the joint which is not supported by external bearings must be forced to rotate about a fixed axis by the joint. If the seal is considered in the aligned state, without articulation, it must not allow a shift of the driving and conducting members of the seal radially relative to each other during use. If the seal does not have sufficient stability, the leading or

  which is not well supported by external bearings

  is not obliged to turn around a fixed axis, so that unacceptable vibrations in a vehicle with

engine appear.

  British Patent No. 2,116,672 discloses a universal joint which has a hollow outer member having grooves axially disposed in its inner wall, an inner member disposed in the outer member and having grooves formed at its outer wall, which correspond to the grooves. of the outer member and are placed in front of them, the grooves of the members being curved in longitudinal section of the seal and the grooves opposite a diverging pair so that they form openings similar to jaws in which accommodate respective balls for transmitting the torque. The configuration of the throats is

  such that the centers of the balls occupy a plane bisecting

  angle of rotation axes of the joint members when it is hinged, obtaining a constant ratio of velocities (homokinetic condition), and the

  balls are retained in the grooves by a pivotal element

  so much support that penetrates the openings of the grooves.

  The internal and external organs of the joint have, between

  grooves, cooperating partially spherical surfaces.

  As described in the aforementioned patent, such a seal is mounted by holding in position the separate parts of the outer member relative to each other so that the axial play of the seal is removed, and then by welding these parts. However, in practice, this method of mounting the seal does not allow the removal of all the games, so that the seal may not have sufficient stability during operation at high speed. If all the parts of the joint were perfect

  and exactly matched their nominal configuration

  nal, all games would be eliminated, but manufacturing tolerances and errors require the presence of games so that the seal does not get stuck when it presents a

  articulation, and this causes the instability described above.

  ously. The games of the assembled seal are imposed by a space

  irregular circumferential circumferentially possible grooves ball housing members of the seals, by errors on the shape of the grooves because they may not have a perfectly constant sectional configuration over their entire length, by concentricity errors and by general irregularities from the surface. These irregularities of the surface are obligatorily present, especially when the manufacture of the grooves of housing of the balls formed in the members of the joint is carried out by an operation of

  forming rather than machining with removal of material.

  Gasket clearance is a particular problem when the seal transmits low or no torque. When transmitting a torque, the forces acting on the balls of the seal put them in positions, relative to the section of the grooves, such that the games are deleted but, when no torque is transmitted, these

conditions do not apply.

  The present invention relates to the realization of a constant velocity universal joint which solves this problem of the instability of the joint or reduces its acuity. Gasket

  must obviously be of inexpensive manufacture.

  In a first aspect, the invention relates to a constant velocity universal joint comprising: an external hollow-shaped member, an internal member disposed at least partly in the outer member, the outer and inner members having partially spherical surfaces which cooperate and allow thus a relative articulation, the external member having several grooves arranged axially and spaced circumferentially in its part

  internal organ, and the internal organ with complementary grooves

  the grooves of the outer member so that the grooves form pairs, the grooves having a curved shape in planes containing the axis of rotation of the respective member and having remote centers of curvature so that the grooves of each pair diverge relative to one another towards a first end of the seal, a closure member of the external member at its first end, several balls each disposed in a pair of

  throats opposite the joint organs so that they

  transmission of the torque between the grooves, a cooperating element with the balls, having an annular shape and supported relative to the closure member of the seal so that it can pivot in all directions and that it cooperates with the balls holding them in the grooves, and a spring device supporting the element of cooperation with the balls so that it repels them

in the gorges of each pair.

  In a seal according to the invention, the support of the element for cooperation with the balls by the spring device has a result such that the balls are always pushed as far as possible in the diverging grooves of the respective pair so that the bodies internal and external remain centered relative to each other. The effect

  of the spring device is particularly valuable when

  that the joint rotates but transmits a weak or zero torque. Under these conditions, the necessary clearances in a seal known hitherto, as described above, would have prevented the maintenance of the balls as much as possible in the converging grooves and the inner and outer parts of the seal would not have been held in position

  centered relative to each other.

  The invention also relates, in another aspect, to a homokinetic universal joint which comprises: an external hollow-shaped member, an internal member arranged at least partly in the external member, the external and internal members having partially spherical surfaces in cooperation that allow a relative articulation of the organs, the outer member having a plurality of circumferentially spaced axial grooves in its inner part, and the inner member having complementary grooves on its outer surface, these grooves being turned towards the grooves of the organ external to which they are associated in pairs, the grooves having a curved shape in planes containing the axis of rotation of the respective member of the joint and having remote centers of curvature so that the

  throats of each pair of throats diverge one

  port to the other towards a first end of the joint,

  the configuration of each groove, in cross-section

  dirty, comprising lateral parts cooperating with the respective ball when the seal transmits a torque, and a base portion, a closure member of the outer member of the seal at the first end, several balls each disposed in the grooves facing a pair of grooves formed in the seal members so that a torque is transmitted between the grooves, a cooperating member with the balls, having an annular shape and supported relative to the sealing member of the seal so that it can pivot in all directions and that it cooperates with the balls by keeping them in the grooves, and a spring device supporting the element of cooperation with the balls so that it repels them in the pairs of grooves, if although the balls are in contact with the base portions of the grooves when the seal

not transmit torque.

  Preferably, the spring device allows a limited displacement of the element of cooperation with the balls and balls towards the end of the joint, in spite of the

  force exerted by the spring device, and a resistance

  greater displacement is then opposed.

  When a seal according to the invention (or in fact any

  universal joint having diverging grooves for the housing

  balls) transmits a couple, the forces acting on

  the balls tend to chase the logs out of

  grooves towards widely spaced ends. In a seal according to the invention, these forces exceed the force exerted by the spring device but, when the balls have moved to the closure member of the outer member of the seal a limited amount allowed by the device to spring, an additional displacement of the balls meets a resistance. When the joint transmits a torque, the balls take in the grooves, with respect to the section thereof, a position such that the internal and external members are in fact centered mutually. When all the bead housing grooves of a joint according to the invention have a cross-sectional configuration, that is to say seen along the length of the groove, which comprises side parts of which one or

  the other is in contact with the ball when the trans-

  sets a torque, depending on the transmission direction of a torque, and a base portion, the spring device pushes the balls as far as possible into the facing grooves until they come into contact with the base portions grooves, when the seal does not transmit torque. The sectional configuration of each groove may be that of a truncated ellipse or a truncated ogive, the elliptical or ogive grooves being well known in the universal joints in which the beads have a contact

said "angular" with the throats.

  Preferably, the seal further comprises a support member having a peripheral support portion of the element for cooperation with the balls, and a central portion supported so that it can pivot in all directions on the closure member. This body of

  support is advantageously a stamped metal element.

  The central part of the support member may have a partially spherical shaped element which cooperates

  with an element of partially spherical shape complemen-

  formed on the sealing member of the seal so that pivoting in all directions is possible. Moon

  at least surfaces of these partially spherical elements

  in contact may have a suitable coating that reduces the

friction.

  Preferably, the spring device is placed between the contact element with the balls and the part

  peripheral of the support member. This device with

  spell may comprise elastic fingers arranged radially

  preferably formed in the peripheral portion of the support member itself. However, it should be noted

  a separate spring can be used. The invention

  also the case in which the spring device acts between the support member and the closure member and not between the support member and the engagement member with the balls. For example, the support member can pivot on a separate member of the closure member and supported

elastically in relation to him.

  Preferably, the peripheral portion of the organ of

  support also forms a stop device which can cooperate

  with the engagement element with the balls after a limited displacement thereof towards the closure member of the seal despite the force exerted by the spring device. The assembly of a seal according to the invention requires the

  adjustment of the closing member and the element of cooperation

  with the balls relative to the outer member of the seal so that, when the seal does not transmit torque, the spring device fully maintains the balls in the grooves, the latter however taking a suitable position when the seal transmits a couple. The process

  setting is described in detail below.

  As previously described, the support of the balls by the cooperation member with the balls and the spring device has an effect such that the necessary stability of the seal is retained despite the errors due to the aforementioned deviations

  relative to the desired configuration of the joint members.

  In particular, this support allows housing grooves

2'619607

  balls of the seal members to be made by forming operations of these bodies without subsequent machining

  gorges with removal of material.

  In a seal according to the invention, the outer member of the seal is normally manufactured by machining and / or grinding operations (called "machining with removal of material") of an element which has been forged or formed into a

  partially completed configuration. As indicated above

  Finally, the bead housing grooves can be made to the desired configuration with sufficient accuracy without the need for subsequent machining with removal of material. Aside from the configuration of

  grooves, the layout and shape of the partial surface-

  spherical shape of the outer member of the joint, between the grooves themselves, are of importance, and the invention allows the measurement of an element in which grooves of

  bead housing was formed during the manufacturing process

  external seal, by axially introducing a member having shape elements corresponding to the position

  Theoretical theory of the balls in the joint, and by

  the position of that body where those elements of

  form are placed against the grooves, as a reference

  for the determination of the position of the partially spherical surface of the external joint member between

the throats of it.

  The formation of the partially spherical surface is normally performed by machining with removal of

  material of the outer joint member, using the reference

  established as indicated above.

  Previous operations ensure obtaining

  of a relation, between the throats and the partial surface-

  spherical shape of the joint member, such that, in the

  mounted seal, the parts of it fit into

both the desired limits.

  Other features and advantages of the invention

  will be better understood by reading the description

26 1 9607

  which will follow examples of embodiment, with reference to the accompanying drawings in which: Figure 1 is an elevation in partial section of an embodiment of seal according to the invention; Figure 2 shows in more detail the inner and outer members of the seal of Figure 1, in section; Figs. 3A to 3E schematically show a portion of the seal showing how it is mounted and the relative provisions of the various parts of the seal during use; Figure 4 is a side elevation in partial section of another embodiment of seal according to the invention;

  Figures 5A and 5B schematically show

  an outer member of a seal according to the invention may be manufactured; and FIG. 6 is a partial section of another mode

  embodiment of seal according to the invention.

  We first refer to Figures 1 and 2 of the

  drawings; the universal joint shown therein comprises an outer member 10 and an inner member 11, the latter being placed in the outer member. The external organ, as better

  shown in FIG. 2, has a partial internal surface

  spherical 12 and the internal organ has a surface

  partially complementary spherical 13 which is

  tact of the surface 12 of the external organ. The seal members can thus have a certain articulation relative to each other. The outer member has a plurality of generally circumferentially spaced grooves 14 generally disposed in the inner portion, and the inner member has complementary grooves circumferentially spaced and facing the grooves of the outer member so that pairs of opposite grooves are formed. As indicated by the sectional part of FIG. 1, by a plane containing the common axis of rotation of the two members of the joint, when these members are aligned with one another (that is to say have no articulation), the grooves 14 have a curved configuration and the grooves 15, in the parts where they are at

  contact of the balls during use, have a configuration

  curved ration. Several balls 16 are each disposed in a pair of grooves 14, 15 so that they ensure the transmission of a torque between the seal members. In the aforementioned plane, the grooves 14 and the grooves 15 have their centers of curvature which are offset relative to each other in known manner so that the grooves diverge relative to each other towards the end. right of the joint (in the drawing) and, when the joint forms a certain angle of articulation, the balls occupy in the grooves positions such as the plane containing the centers of the joints.

  ball is the plane bisecting the angle of the rotational axes

  internal and external organs. This gives the joint constant-speed performance characteristics

  velocities (homokinetic property).

  The outer member 10 of the seal has its right end which is closed by a member 17 fixed to the outer member by welding, for example by a laser or by an electron beam. The closure member 17 provides the connection,

  for example by welding, to a tubular shaft member 18.

  The inner member 11 has a splined hole 19 which houses an end splined portion of a solid shaft 21. An elastic ring 22 holds the shaft portion 20 in the inner member 11. The opposite end of the shaft 21 has a flange 23 having openings for its bolting

  on a rotating drive element used.

  A flexible annular elastomeric cap 24 for sealing

  It is intended to enclose the universal joint so that it retains the lubricant inside and prevents the entry of dirt. This cap has a first end portion 25

  housed on the outer member 10 in contact with an annular groove

  26 is formed outside thereof and is retained by a protective metal housing 27. The other end portion 28 of the cap is held in contact

  an annular groove 29 by a retaining ring 30.

  The balls 16 are in contact with an annular element 31 for cooperation with the balls. A circular support member 32 has its periphery placed in contact with the element 31 and its center has a concave member 33 which can pivot on the ball 34. The latter is housed in a bowl 35 held by the closure member 17 . A spring 36 is disposed between the element 31 for cooperation with the balls and the support member 32 so that the first one is pushed back.

  compared to the second to the balls 16.

  The nature of the cooperation of the cooperation element 31, the spring 36 and the support member 32

  appears more clearly in FIGS. 3A to 3E of FIGS.

  drawings. It should be noted that the element 31 has an abutment surface 37 which is in contact with the support member 32 after a limited displacement of the element 31 relative to the member 32 towards the seal closure member 17 . The spring 36

  may have several elastic fingers protruding radially

  of a central annular part which is in contact with

of the organ 32.

  When mounting the seal, the appropriate relative arrangement must be determined between the outer member 10

  and the closing member 17 so that the element 31 of cooperation

  with the balls, the support member 32 and the resistor

  spell 36 cooperate properly. In particular, the

  fate must ensure, through the element 31, the maintenance of the balls to the greatest possible depth in their grooves when the seal does not transmit

  couple. At the same time, the balls must be able to move

  along the axis of the joint when a torque is transmitted, despite the force exerted by the spring device, until the limit of this displacement which undergoes an elastic resistance is reached, a resistance more

  large being then opposed to the movement of the balls.

  For this purpose, the seal is mounted and the member 17 of

  closure can be moved to the left, on the

  sins, relative to the outer member to the position shown in Figure 3A. Thus, when the balls 16 are pushed as far as possible into the grooves that converge, the abutment surface 37 of the element 31 for cooperation with the balls is in contact with the support member 32 so that the assembly is very firm. The closure organ 17 is then brought back a predetermined distance back and is welded to the outer member of the seal. Then, when the seal does not transmit torque, the relative arrangement shown in Fig. 3B is assumed, i.e. the balls are pushed as far as possible into the converging grooves formed in the joint members. under the action of spring 36,

  so that the balls are driven into the grooves.

  When a torque is transmitted by the joint, the existing situation is that of Figure 3C. Given the forces acting on the balls because of the configuration of the

  gorges that converge, the marbles move towards the ex-

  groove diverging so that the element 31 contact with the balls is returned back despite the action of the spring 36. The amplitude of the displacement of the

  balls towards the end of the diverging grooves is deter-

  undermined by the force applied from the transmitted torque.

  However, the element 31 finally comes into contact with the member 32 and no further displacement of the balls

is not possible.

  Figures 3D and 3E show, in cross section,

  versale, one of the grooves 14 of the outer member 10 of the seal. The sectional configuration of the groove is that of a truncated ellipse or a truncated ogive, comprising curved lateral portions 140 and a flat portion 141 of base. Figure 3D shows the position of the ball 16 when the seal does not transmit torque, as shown in Figure 3B. The ball is supported at the bottom of the groove, in contact with the base portion 141. Figure 3E shows the position of the ball in the groove when a torque is transmitted and corresponds to Figure 3C. The ball is spaced from the base 141 of the groove and is in contact with one of the lateral parts 140 thereof, theoretically at a point but in practice in a whole curved region 143 of application of a contact pressure . This mode of

  cooperation of the balls with the lateral parts of the

  Housing housings formed in the components of the seals are well known in universal joints with so-called "angular" contact. In addition, the relative arrangement of the element for cooperation with the balls and the support member, with return by a spring, is such that all small

  irregularities in geometrical dimensions and configuration

  Due to the manufacturing tolerances, they are absorbed, and the flexibility is sufficient for the balls to be always held in the grooves without play in the joint.

considered as a whole.

  When the seal rotates articulated, the element 31 for cooperation with the balls and the support member 32 pivot around the ball 34 under the action of a pivoting plate. As the center around which the joint rotates

  does not coincide with the center of flexion of the joint, a displacement

  relative radial cement must exist between the balls 16 and the element 31 of cooperation with the balls when they are

in touch.

  Reference is now made to Figure 4; it represents

  in a manner corresponding to FIG. 1, to another embodiment of the seal according to the invention. The main elements of the seal that are identical to those of Figure 1 are not described in detail, and it is in particular the external member, the internal member having the solid shaft, transmission balls of torque and the assembly forming the sealing cap. The seal differs from that of FIG. 1 by the configuration of the closure member of the external member, and by the element of cooperation with the balls and the member

corresponding support.

  The element 40 for cooperation with the balls of the joint of FIG. 4 is a rigid annular member but having

  a configuration slightly different from that of the

  31 cooperation with the balls. The support member is formed by a stamped metal member 41 whose center 42 has a dome-shaped projection forming a partially spherical surface. The periphery of the member 41 has radially protruding resilient fingers 43 which are in contact with the element 40 and alternately placed with stop fingers 44 which have greater rigidity than the elastic fingers 43. The selection of a suitable material for the support member 41 and its realization with integral elastic fingers and

  stop fingers 43, 44 eliminates the need for the use of

  The closure member 45 is also a stamped metal member whose center 46 forms a partially spherical bowl and whose periphery has a generally cylindrical wall. intended to be welded to the outer member of the seal and to the tubular shaft member. The seal of FIG. 4 is mounted in the same manner as previously described with reference to the seal of FIG. 1. The elastic fingers 43 placed at the periphery of the support member 41 elastically recall the element of cooperation with the balls in order to that the latter are maintained at the greatest depth possible in the respective grooves when the seal does not transmit torque, but when the seal transmits a torque, the element

  cooperation with logs may exceed

  despite the resistance presented by the elastic fingers

  43 until the stop fingers 44 are in

  stop and increase the resistance to displacement considered.

  Since the beads are maintained in the

  grooves of the joint members by being recalled elastically

  and thus allow the absorption of small irregularities

  the dimensions and configuration of the joint, the

  internal and external members of the joint according to the invention

  are particularly well suited for manufacturing largely by forging or metal forming techniques rather than by metal removal machining. As

  shown in FIG. 2, in a preferred embodiment

  joint, the grooves 14, 15 can be made by

  forming. Only partially spherical surfaces 12, 13

  components of the joint must be machined to the

final management.

  It should be noted that when a joint member is manufactured by a forging or forming technique, the dimensions of some parts vary with

  such as the wear of the tools used for the

  nufacturing. In a method of manufacturing the external member of a seal according to the invention, an organ is partially

  formed, log grooves having been made therein.

  formed by a forming operation, and being calibrated by axially introducing an element having circumferentially spaced members and having surface portions whose configuration corresponds to that of the joint balls, said ball-shaped members being placed on the desired pitch diameter. The penetration distance of this member into the member is determined by the fact that the ball-receiving grooves formed in the member are at one end or the other of the range of tolerances. The position of the element introduced, when the organs they carry are at the bottom of the grooves of the external member, is used as a reference for the

  subsequent manufacture by machining the partial part

  spherical member of the outer member of the joint between the grooves. This embodiment is illustrated by FIGS. 5A

and 5B.

  Figures 5A and 5B represent external organs

  50 of partially completed seals, having grooves 51

  housing balls that have been formed. When a

  calibration 52 having a plurality of spaced apart members

  53 is introduced axially through the right end of the member, it penetrates until the members 53 are in abutment against the grooves 51, the penetration distance depending on the fact that the dimensions of the grooves 51 correspond to a first end of the tolerance range as shown in Figure 5A or at the other end of this range as shown in Figure 5B. The position of the element 52 is then used as a reference for the removal of excess material from the ends of the organ 50 as indicated by the broken lines 54. The axial dimension of the completed organ is indicated by the reference 57. This manufacture of the outer member of the seal allows the mounting of the seal as described above, and the seal has the necessary radial stability. The elastic retention of the balls in the grooves is such that the variation of the inclination of the

  grooves housing balls relative to the rotational axis

  tion of the joint member, when the balls are

  in contact, does not affect the operation of the seal.

  The same principle can also be used for

  manufacture of the internal organ, with a calibration element

  brage of suitable form. However, in general,

  the internal body does not pose the same problems of defor-

  during the manufacturing process that the external organ

  although the above method is not essential.

  Referring now to Figure 6 which shows a seal having an outer member 60 which is substantially

  same configuration as the external organs described above.

  ously. The seal further comprises an internal member 61 which is integral with a shaft portion 62. The outer and inner members 60, 61 of the seal have curved grooves for accommodating torque transmission balls such as 63, and partially spherical surfaces which cooperate between the grooves as previously described in FIG.

  reference to the joints of Figures 1 and 4.

  A closure member 64 is attached by welding to the outer member and provides attachment to a tubular shaft member 65. The center of the closure member 64 has a projection 66 having a partially spherical surface at its end, the center of curvature of this surface located in the center of articulation of the universal joint,

  that is to say at the center of curvature of the partial surfaces

  complementary spherical members of the outer and inner members of the seal as indicated by reference 67. This partially spherical surface of the closure member 64 constitutes a support for the pivoting of the seal support member 68 which is a circular element formed of a metal sheet whose periphery has, at 69, resilient fingers and stop fingers which cooperate with a member 70 for cooperation with the balls, in a manner similar to that of the corresponding elements of the joints described above. The center 71 of the support member 68 forms a bowl for pivoting on the partially spherical surface of the end of the portion 66 of the closure member 64. The inner member 61 has a relatively deep axial cavity 72 for accommodating the parts 66 of the closure member 71 and the support member. In the seal of Figure 6, when the seal has a hinge, the support member 68 pivots about the bending center of the seal. Consequently, the relative radial movement previously described of the balls and the element of cooperation with the balls of the joint does not exist. This may have the advantage of reducing the internal friction of the joint and consequently of clearing

  less heat during use.

  Of course, various modifications can be made by those skilled in the art to the joints and processes which have just been described as examples only.

  non-limiting without departing from the scope of the invention.

Claims (15)

  1. Homokinetic universal joint, characterized in that it comprises: an outer member (10; 60) of hollow form, an inner member (11; 61) of hollow form placed at least partially in the outer member, the outer members and inner having partially spherical surfaces (12, 13) which cooperate to allow relative articulation of the members,   the outer member having a plurality of grooves (14)   axially and spaced apart circumferentially in its   inner portion, and the inner member having internal grooves   elements (15) formed on its external face and facing the grooves of the outer member so that they are associated in pairs, the grooves (14, 15) having a curved shape in planes containing the axis of rotation of the respective member of the joint and having centers of curvature spaced so that the   grooves of each pair diverge one from the other   to a first end of the seal, a closure member (17; 45; 64) which closes the outer member of the seal at the first end, a plurality of balls (16,63) each placed in a pair of grooves facing the members; of the seal so that they transmit a torque between the members, a member (31; 40; 70) for engagement with the balls, having an annular shape and supported relative to the closure member of the seal so that it allows a pivoting in all directions and cooperating with the balls and holding them in the grooves, and a spring device (36; 43; 69) supporting the engagement member with the balls so that the balls   be pushed back into the pairs of throats.   2. Homokinetic universal joint, characterized in that it comprises: an outer member (10; 60) of hollow form, an inner member (11; 61) of hollow form placed at least partially in the outer member, the outer members and internal having surfaces   partially spherical (12, 13) which co-operate.   that they allow a relative articulation of the organs, the external member having several grooves (14) arranged axially and spaced circumferentially in its   inner portion, and the inner member having internal grooves   elements (15) formed on its external face and facing the grooves of the outer member so that they are associated in pairs, the grooves (14, 15) having a curved shape in planes containing the axis of rotation of the respective member of the joint and having centers of curvature spaced so that the   grooves of each pair diverge one from the other   to a first end of the seal, the cross-sectional configuration of each of the grooves including side portions (140) for   to cooperate with the respective ball when the trans-   a pair, and a base portion (141), a closure member (17; 45; 64) which closes the outer member of the seal at the first end, a plurality of balls (16,63) each placed in a pair of grooves facing the members of the joint so that they transmit a torque between the members, a member (31; 40; 70) for cooperation with the balls, having an annular shape and supported relative to the sealing member of the joint so as to it allows pivoting in all directions and co-operates with the balls and holds them in the grooves, and a spring device (36; 43; 69) supporting the co-operating element with the balls so that are pushed back into the pairs of grooves, so that the balls are in contact with the base portions (141) of the   grooves when the seal does not transmit torque.   3. Joint according to one of claims 1 and 2,   characterized in that the spring device (36; 43; 69) allows limited movement of the engagement member with the balls and balls towards the end of the seal despite the force exerted by the spring device, and   greater resistance is then opposed to this placement.   4. Seal sekon any of the claims   previous, characterized in that the configuration, in cross section, of each of the grooves (14, 15) is that of a truncated ogive or a truncated partial ellipse.   5. Seal according to any one of the claims   preceding, characterized in that it further comprises a   support member (32; 41; 68) having a peripheral portion   supporting the engagement element with the balls, and a central portion (33; 42; 71) supported so as to   that it can rotate in all directions on the or- closing gate (17; 45; 64).   6. Joint according to claim 5, characterized in that the central portion (33; 42; 71) of the body of   support and the closure member have partial   cooperating spherical elements (34; 46; 66).   7. Joint according to one of claims 5 and 6,   characterized in that the spring device (36; 43; 69) is placed between the cooperative element with the   balls and the peripheral portion of the support member.   8. Joint according to claim 7, characterized in that the spring device comprises resilient fingers (43; 69) arranged radially and formed in the part   peripheral of the support member.   9. Seal according to claim 8, characterized in that the peripheral portion of the support member forms   also a stop device intended to cooperate with the   cooperation with the logs after mal-   thanks to the force exerted by the spring device.   10. Seal according to any one of the claims   precedents, characterized in that the element (70) of cooperation   ration with the balls pivots around the center of flexion of the seal. 261960-7   11. Seal according to any one of the claims   previous, characterized in that the outer member of the seal has its grooves (14) formed by a forming process and its partially spherical surface (12) machined to its final configuration. 12. Joint according to claim 11, characterized in that the machining is performed with respect to a reference established by measuring a partially completed member in   which gorges were formed.   13. Joint according to claim 12, characterized in that the measurement is made by axial introduction into the partially completed member of an element having shaped members corresponding to the desired theoretical position of the balls in the joint, and by use, as   reference, of the position of that element when its   Nes of suitable form are supported in the grooves.   14. A method of manufacturing an external member of a seal according to claim 12, characterized in that it comprises: the production of a partially completed member, in which grooves housing balls were formed, the measurement grooves so that a reference is established with respect to the member, and the machining of the partially spherical surface at   less of the joint member compared to the reference.   15. The method of claim 14, characterized in that it further comprises the axial introduction into the partially completed member of an element having members whose configuration corresponds to the position.   theoretically for the balls in the joint, and the use of   as a reference, the position of this element when its organs of suitable form are supported in the throats.