FR2795786A1 - Sliding shaft coupling e.g. for vehicle steering column comprises spring-loaded balls in concave channels in inner and outer shafts - Google Patents

Abstract

The coupling for inner (1) and outer (2) axially sliding shafts consists of a series of balls (3), each set in concave channels (16, 17) in the outer and inner shafts. Each ball has one or more springs (22, 23, 25) between it and the concave channel in one of the shafts. The balls, which can be in supporting cages, are set in a number of axial rows, with the channels containing the springs shaped to form a base (21) and two flat sloping sides (19, 23) to act as thrust surfaces for the springs.

Description

The invention relates to a coupling device in rotation of two sliding shafts along their common axis. <B> Two-shaft ball coupling device </ B> <B>. The coupling device of the invention applies in particular to a motor vehicle steering column, by adopting it at the intermediate column portion connected to the steering box, or at the upper column connected to the steering wheel. .

In the particular case of the intermediate axis, it has a universal joint at each end a gimbal is connected to the movement input of the steering box, and the other gimbal is connected to the top of the column. In order to have a correct direction of current motor vehicles, it is necessary that the length of the intermediate axis is variable and adapts to oscillations of the front axle of the vehicle, which are due to the profile and the surface condition of the coating of the vehicle. the road.

The intermediate axis must therefore first have a variable length, that is to say it must have a sliding function of two shafts relative to each other along their common axis, which is the axis of the intermediate part. In addition, it requires a transmission function of the rotational movement between the two shafts, and the torque required to maneuver the direction.

There are many sliding shaft coupling devices, which allow to associate the passage of the torque between the two shafts by the use of splines, which are arranged on each of the two shafts with conjugate profiles. However this type of device presents a clear game after a cycle of endurance of 150000 km, which is the one asked on current cars. In order to delay the appearance of this free play, the adjustment of the sliding of the two shafts during manufacture is relatively tight, which requires during assembly chain, a relatively large axial force, hence a longer assembly time important and more painful in the realization of this assembly.

This adjustment must be precise to allow the correct absorption of axial movements in operation. Except during the passage of torque, the axial force is a function of the torque to be transmitted, there is then a phenomenon of axial locking of the two shafts, then a brutal axial release, hence the appearance of jerks detrimental to maintaining a good sliding fit with reduced play; and detrimental to a good driving impression. The object of the present invention is to provide a sliding shaft coupling device that avoids the above disadvantages, that is to say a device that requires an axial force that is not related to the torque to be transmitted. It is therefore necessary that the axial force increases very little when the torque to be transmitted increases. In addition, there must be no appearance of free play after the endurance cycle, and that the coupling device of the two shafts can be easily mounted in the existing possible congestion on motor vehicles, and this with a reduced axial force of establishment. The invention relates to a device for coupling two shafts: an inner shaft and an outer shaft which slide one inside the other in the direction of their common axis. Said device for coupling the two shafts comprises rolling elements, which are arranged between the inner shaft and the outer shaft.

In the coupling device, each of said rolling elements is disposed on the one hand in a concave portion of the inner shaft, and on the other hand in a concave portion of the outer shaft. Each of said rolling elements is provided with at least one elastic element, which is disposed between said rolling element and the corresponding concave part of one of the two shafts.

The mounting of each of the rolling elements is carried out so that at rest, when there is no torque transmission, each rolling element is always in contact on the side of the elastic element (s), and on the opposite side ; and so that when there is torque transmission, there is for each rolling element, a bearing zone on the side of the elastic element (s), and a bearing zone on the opposite side.

Preferably according to the invention, the rolling elements are balls.

According to different variants of the invention, each of the balls is provided with one, two or three elastic elements, which is / are arranged between the corresponding concave portion and said ball. Each of the elastic elements is a spring with a bearing pad against the corresponding ball.

In one type of assembly of the invention, each of the balls moves on two races which are pushed against said ball by the same corresponding elastic element. The raceways are arranged between said ball and the corresponding elastic element.

In another type of assembly of the invention, each of the balls moves on two races with two elastic elements. Each of the raceways is pushed against said ball by the corresponding elastic element. Each of said raceways is disposed between said ball and the corresponding elastic element.

In order to avoid any friction of the balls against each other, the balls are arranged in at least one holding cage.

In order to increase the operational safety of the coupling device of the invention, male grooves and female grooves, having profiles with a certain clearance, are arranged on the inner shaft and on the outer shaft, so that in case of breakage of the balls, the torque can still be transmitted between the inner shaft and the outer shaft.

Several structures of the coupling device can be developed. In a structure, the elastic element or elements is / are arranged in the inner shaft. In another structure, the elastic element or elements is / are arranged in the outer shaft.

In another structure, the elastic elements are arranged for some in the inner shaft, and for the others in the outer shaft.

In a particular arrangement of the invention, the coupling device has the balls which are arranged in several axial rows; the balls being held in place relative to each other by a cage.

For each row of balls, there is arranged in the outer shaft a concave portion in the form of an axial groove, the section comprises two concave faces inclined relative to each other, which come into contact with the balls.

For each row of balls, there is arranged in the inner shaft a concave portion in the form of an axial groove, the section has a bottom and two sides, the bottom being substantially perpendicular to the diametral plane passing through its middle.

For each row of balls, two raceways are arranged in the concave portion in the form of an axial groove of the inner shaft. Each raceway is in the form of an axial bar. The section of each raceway has a concave face which comes into contact with the balls, two faces contiguous with respect to each other, and which are respectively arranged opposite the bottom and one of the sidewalls. the axial groove, and - a face inclined relative to the bottom of the axial groove.

For each row of balls, an elastic element, in the form of an elastic axial coil whose section is circular, is disposed in the axial groove between the two races. Said elastic axial flange bears against the bottom of the axial groove, in order to push the inclined face of each of the two raceways.

In another particular embodiment of the invention, the coupling device has the balls which are arranged in several axial rows, the balls being held in place relative to one another by a cage.

For each row of balls, there is arranged in the inner shaft a concave portion in the form of an axial groove, the section comprises two concave faces inclined relative to each other, which come into contact with the balls.

For each row of balls, there is arranged in the outer shaft a concave portion in the form of an axial groove whose section comprises a bottom and two sides, the bottom being substantially perpendicular to the diametral plane passing through its middle.

For each row of balls, two raceways are arranged in the concave portion in the form of an axial groove of the outer shaft. Each raceway is in the form of an axial bar. The section of each raceway has a concave face which comes into contact with the balls, two faces contiguous with respect to each other, and which are respectively arranged opposite the bottom and one of the sidewalls. the axial groove, - a face inclined relative to the bottom of the axial groove.

For each row of balls, an elastic element, in the form of an elastic axial coil whose section is circular, is disposed in the axial groove between the two races. Said elastic axial flange bears against the bottom of the axial groove, in order to push the inclined face of each of the two raceways.

In another particular embodiment of the invention, the coupling device has the balls which are arranged in several axial rows, the balls being held in place relative to one another by a cage.

For each row of balls, there is arranged in the outer shaft a concave portion in the form of an axial groove whose section comprises two concave faces inclined relative to each other, which come into contact with the balls.

For each row of balls, there is arranged in the inner shaft a concave portion in the form of an axial groove whose section comprises a bottom and two sides, the bottom being substantially perpendicular to the diametral plane passing through its middle.

For each row of balls, two raceways are arranged in the concave portion in the form of an axial groove of the inner shaft. Each raceway is in the form of an axial bar. The section of each raceway has a concave face which comes into contact with the balls, two faces contiguous with respect to each other, and which are respectively arranged opposite the bottom and one of the sidewalls. the axial groove, - a bead which is arranged on the face of the bottom side at the corner of the other face.

For each row of balls, there is an elastic element in the form of elastic axial flange, whose section has an axial base and two axial protuberances. Said elastic axial flange is disposed in the axial groove between the beads of the two raceways. The axial base is supported on the bottom of the axial groove, so that each of the two axial protuberances pushes the corresponding raceway. In another particular embodiment of the invention, the coupling device has the balls which are arranged in several axial rows, the balls being held in place relative to one another by a cage.

For each row of balls, there is arranged in the inner shaft a concave portion in the form of an axial groove whose section comprises two curved faces with respect to one another, which come into contact with the balls.

For each row of balls, there is arranged in the outer shaft a concave portion in the form of an axial groove whose section comprises a bottom and two sides, the bottom being substantially perpendicular to the diametral plane passing through its middle.

For each row of balls, two raceways are arranged in the concave portion in the form of an axial groove of the outer shaft, each raceway is in the form of an axial bar.

The section of each raceway has a concave face which comes into contact with the balls, two faces contiguous with respect to each other, and which are respectively arranged opposite the bottom and one of the sidewalls. the axial groove, - a bead which is arranged on the face of the bottom side at the corner of the other face.

For each row of balls, there is an elastic element in the form of elastic axial flange, whose section has an axial base and two axial protuberances. Said elastic axial flange is disposed in the axial groove between the beads of the two raceways. The axial base is supported on the bottom of the axial groove, so that each of the two axial protuberances pushes the corresponding raceway.

In another particular embodiment of the invention, the coupling device has the balls which are arranged in several axial rows, the balls of each axial row being held in place relative to one another by a cage.

For each row of balls, there is arranged in the outer shaft a concave portion in the form of an axial groove whose section comprises two curved faces with respect to one another, which come into contact with the balls.

For each row of balls, there is arranged in the inner shaft a concave portion in the form of an axial groove whose section comprises a bottom and two sides, the bottom being substantially perpendicular to the diametral plane passing through its middle. For each row of balls, two raceways are arranged in the concave portion in the form of an axial groove of the inner shaft. Each raceway is in the form of an axial bar, the section of which has a curved shape in order to come into contact with the balls.

For each row of balls, two elastic elements, in the form of elastic axial flange, are arranged in the axial groove. Each elastic element comes to bear on the bottom and on one of the flanks of the axial groove to push on the corresponding raceway.

In another particular embodiment of the invention, the coupling device has the balls which are arranged in several axial rows, the balls of each axial row being held in place relative to one another by a cage.

For each row of balls, there is arranged in the inner shaft a concave portion in the form of an axial groove whose section comprises two curved faces with respect to one another, which come into contact with the balls.

For each row of balls, there is arranged in the outer shaft a concave portion in the form of an axial groove whose section comprises a bottom and two sides, the bottom being substantially perpendicular to the diametral plane passing through its middle.

For each row of balls, two raceways are arranged in the concave portion in the form of an axial groove of the outer shaft. Each raceway is in the form of an axial bar, the section of which has a curved shape in order to come into contact with the balls.

For each row of balls, two elastic elements in the form of elastic axial flange are arranged in the axial groove. Each elastic element is supported on the bottom and on one of the flanks of the axial groove, in order to push on the corresponding raceway.

In a particularly well balanced arrangement of the coupling device, the balls are arranged in three axial rows. The axial rows are transversely 120 from each other. The inner shaft is provided with three axial grooves, the axial grooves being transverse to each other. The outer shaft is provided with three axial grooves, the axial grooves being transverse to each other. In another particularly well balanced arrangement of the coupling device, the balls are arranged in two diametrically opposite axial rows. The inner shaft is provided with two diametrically opposed axial grooves. The outer shaft is provided with two diametrically opposed axial grooves.

In a complete architecture of the coupling device according to the invention, the inner shaft is provided with three axial grooves, the axial grooves being transverse to each other 120. In each axial groove are mounted an elastic element in the form of elastic axial flange and two raceways in the form of axial bar.

The balls are arranged in three axial rows, the axial rows being transverse to each other 120, the balls being held in place relative to each other by a sleeve-shaped cage.

The whole of the ball sleeve with the raceways and the elastic axial flanges is closed at each axial end by a retaining ring. Each retaining ring engages in each of the axial grooves of the inner shaft, one of the retaining rings bearing against a rod which is mounted in a groove of said inner shaft.

The outer shaft is provided with three axial grooves transverse to 120 of each other, which slide on the rows of balls. The axial grooves have the desired length to allow the requested axial sliding of the outer shaft and the inner shaft. The coupling device according to the invention applies very well either to the intermediate portion of a steering column of a motor vehicle, or to the upper part of a steering column of a motor vehicle. The coupling device of two shafts according to their common axis according to the invention thus has the advantage of always having a rolling bearing of balls, which are always in contact even when there is no torque transmission of rotation.

In addition, there is a reduced axial force that is necessary during assembly chain. The precise adjustment of the coupling device of the invention makes it possible to avoid axial jolts during the driving of the vehicle, and guarantees good resistance to endurance, avoiding the appearance of free play in the coupling. . In addition, during the passage of the rotational torque, the axial force is not a function of this torque. Finally, the coupling device can be easily mounted in the existing size of the steering columns of a motor vehicle. Other features and advantages of the present invention will appear more clearly on reading the following description of several preferred embodiments of the invention with reference to the corresponding appended drawings in which - Figure 1 is a schematic perspective view of a direction motor vehicle, wherein the coupling device of the invention applies to the intermediate portion of the column; FIG. 2 is a schematic partial section along II-II of FIG. 1; - Figure 3 is an axial view of the intermediate portion of the motor vehicle steering of Figure 1, which is shown in partial axial section another embodiment of the invention; FIG. 4 is an exploded perspective view of the assembly of the coupling device of FIG. 3; - Figure 5 is a cross section along V-V of Figure 3; Figure 6 is an enlarged partial view of Figure 5; - Figure 7 is a partial cross section similar to Figure 6 of another embodiment of the invention; - Figure 8 is a partial cross section similar to Figure 6 of another embodiment of the invention; - Figure 9 is a partial cross section similar to Figure 6 of another embodiment of the invention; FIG. 10 is a cross-section along the plane of FIG. 5 of another embodiment of the invention; FIG. 11 is a cross-section along the plane of FIG. 5 of another embodiment of FIG. FIG. 12 is a cross-section along the plane of FIG. 5 of another embodiment of the invention. The invention relates to a device for coupling in rotation two shafts that slide one in the other according to their common axis.

This coupling device is particularly applicable to a motor vehicle steering, such as that shown schematically in Figure 1.

The direction shown comprises a steering column with an upper part of column 6 also called top of column, and an intermediate column portion 7 also called intermediate axis.

The column upper part 6 is connected at its upper end to the steering wheel 5, and at its lower end to the intermediate column portion 7.

The intermediate column portion 7 is connected at its upper end to the upper part of the column 6, and at its lower end to the steering box 8 of the steering rod 9.

The intermediate column portion 7 is connected at each of its ends by means of a cardan joint articulation referenced 14 for the upper part of column 6, and referenced 15 for the steering box 8.

In what follows, the description relates to a coupling device which is arranged in the intermediate portion of column 7. The coupling device of the invention can also be arranged in the upper part of column 6.

FIG. 2 schematically represents, in partial cross-section, the intermediate column portion 6, with the principle of the device for coupling in rotation of two shafts according to the invention. An inner shaft 1 and an outer shaft 2 slide one in the other in the direction of their common axis 4, which is shown in Figures 3 and 4. The coupling device of the two shafts comprises rolling elements, which are beads 3 in the various embodiments described below. The balls 3 are disposed between the inner shaft 1 and the outer shaft 2. In the coupling device of the invention, each of said rolling elements or ball 3 is disposed on the one hand in a concave portion 17 of the inner shaft 1, and secondly in a concave portion 16 of the outer shaft 2.

Each of said rolling elements or ball 3 is provided with at least one elastic element which is disposed between said rolling element or ball 3 and the corresponding concave portion 17 of the inner shaft 1. The elastic element or the elastic elements can also be arranged between the rolling element or the ball 3 and the corresponding concave part 16 of the outer shaft 2.

The coupling device is arranged so that at rest, when there is no torque transmission, each rolling element or ball 3 is always in contact on the side of the elastic element (s), and always in contact on the opposite side. The coupling device is also arranged so that when there is torque transmission, there is for each rolling element or ball 3, a bearing zone on the side of the elastic elements /, and a zone d support on the opposite side.

In the case of Figure 2, each ball 3 is disposed in the concave portion 16 of the outer shaft 2. This concave portion 16 is formed of two curved faces 18 and 20, which are inclined relative to the other, so that there is a contact zone 30 between the ball 3 and the curved face 18 and a contact zone 32 between the ball 3 and the curved face 20.

Each ball 3 is also disposed in the concave portion 17 of the inner shaft 1. This concave portion 17 is formed of a bottom 21, and two sides 19 and 23 which in the case of Figure 2 are inclined with respect to background 21.

An elastic element or spring 22 is disposed between the sidewall 19 and the ball 3, another elastic element or spring 25 is disposed between the bottom 21 and the ball 3, and finally another elastic element or spring 27 is disposed between the flank 23 and the ball 3.

In addition, a support pad 24 is interposed between the spring 22 and the ball 3, in order to have a contact zone 29 between the ball 3 and the support pad 24. Another bearing pad 26 is inserted between the spring 25 and the ball 3, in order to have a contact zone 31 between the ball 3 and the support pad 26. Finally, another support pad 28 is interposed between the spring 27 and the ball 3, in order to to have a contact zone 33 between the ball 3 and the support pad 28.

In an alternative embodiment, a single elastic element or spring 25 is used between the bottom 21 and the bearing pad 26 of the ball 3 with a single contact zone 31.

In another alternative embodiment, two elastic elements are used the springs 22 and 27. The spring 22 is disposed between the side 19 and the bearing pad 24 of the ball 3 with a contact zone 29; while the spring 27 is disposed between the flank 23 and the bearing pad 28 of the ball 3 with a contact zone 33.

The assembly in axial view of the intermediate column portion 7 is shown in Figure 3. The inner shaft 1 and the outer shaft 2 slide with the balls 3 along their common axis 4. The intermediate column portion 7 is connected to the steering box 8 by the universal joint 15, and is connected to the upper part of the column 6 by the universal joint 14.

The coupling device, shown in exploded view in FIG. 4 and in cross-section in FIGS. 5 and 6, comprises balls 3 which are arranged in three axial rows 40. The axial rows 40 are situated transversally to 120 of the other. The inner shaft 1 is provided with three axial grooves 41, which are located transverse to 120 of each other. The outer shaft 2 is provided with three axial grooves 42, which are located transverse to 120 from each other.

The balls 3 are held in place relative to each other by a single cage 43. For each row 40 of balls 3, there is arranged in the outer shaft 2 a concave portion in the form of an axial groove 42, the section comprises two concave faces 44, 45 inclined relative to each other, which come into contact with the balls 3.

For each row 40 of balls 3, there is arranged in the inner shaft 1 a concave portion in the form of an axial groove 41, whose section comprises a bottom 46 and two sides 47 and 48. The bottom 46 is substantially perpendicular to the diametral plane passing through his middle. For each row 40 of balls 3, there are two raceways 50, which are arranged in the concave portion in the form of an axial groove 41 of the inner shaft 1. Each raceway 50 is in the form of an axial bar. The section of each raceway 50 has a concave face 51 which comes into contact with the balls 3, two contiguous faces 53 and 52 relative to each other, and which are respectively arranged opposite the bottom 46. and one of the flanks 47 and 48 of the axial groove 41, - an inclined face 54 with respect to the bottom 46 of the axial groove 41.

For each row 40 of balls 3, an elastic element, in the form of an elastic axial coil 57 whose section is circular, is disposed in the axial groove 41 between the two raceways 50. Said elastic axial sleeve 57 bears on the bottom 46 of the axial groove 41, to push the inclined face 54 of each of the two races 50.

In the embodiment shown in Figure 7, the balls 3 are arranged in three axial rows 40. The axial rows 40 are located transversely to 120 from each other. The balls 3 are held in place relative to one another by a single cage 43.

For each row 40 of balls 3, there is arranged in the inner shaft 1 a concave portion in the form of an axial groove 61, whose section comprises two concave faces 63, 64 inclined relative to each other, which come in contact with the balls 3. For each row 40 of balls 3, there is arranged in the outer shaft 2 a concave portion in the form of an axial groove 62 whose section comprises a bottom 65 and two flanks 66 and 67. The bottom 65 is substantially perpendicular to the diametral plane passing through its middle.

For each row 40 of balls 3, there are two raceways 70, which are arranged in the concave portion in the form of an axial groove 62 of the outer shaft 2. Each raceway 70 is in the form of an axial bar. The section of each raceway 70 has a concave face 71 which comes into contact with the balls 3, two contiguous faces 73 and 72 relative to each other, and which are respectively arranged opposite the bottom 65 and one of the flanks 66 or 67 of the axial groove 62, - an inclined face 74 with respect to the bottom 65 of the axial groove 62.

For each row 40 of balls 3, an elastic element, in the form of an elastic axial coil 57 whose section is circular, is disposed in the axial groove 62 between the two raceways 70. Said elastic axial coil 57 is supported on the bottom 65 of the axial groove 62, in order to push the inclined face 74 of each of the two races 70.

In the embodiment shown in FIG. 8, the balls 3 are arranged in several axial rows 40. The balls 3 are held in place relative to one another by a single cage 43.

For each row 40 of balls 3, there is arranged in the outer shaft 2 a concave portion in the form of an axial groove 82 whose section comprises two concave faces 83, 84 inclined relative to each other, which come into contact with the beads 3.

For each row 40 of balls 3, there is arranged in the inner shaft 1 a concave portion in the form of an axial groove 81 whose section comprises a bottom 85 and two sides 86 and 87. The bottom 85 is substantially perpendicular to the diametral plane passing through. by his environment.

For each row 40 of balls 3, there are two raceways 90, which are arranged in the concave portion in the form of an axial groove 81 of the inner shaft 1. Each raceway 90 is in the form of an axial bar. The section of each raceway 90 has a concave face 91 which comes into contact with the balls 3, two contiguous faces 93 and 92 relative to each other, and which are respectively arranged opposite the bottom 85 and one of the flanks 86 or 87 of the axial groove 81.

- A bead 94 is arranged on the face 93 at the corner of the face 92.

For each row 40 of balls 3, there is an elastic element, in the form of an elastic axial coil 97 whose section has an axial base 98 and two axial protuberances 99. Said elastic axial strip 97 is disposed in the axial groove 81 between the The axial base 98 bears on the bottom 85 of the axial groove 81, so that each of the two axial protuberances 99 pushes the corresponding raceway 90. In the embodiment shown in FIG. 9, the balls 3 are arranged in several axial rows 40. The balls are held in place relative to one another by a single cage 43.

For each row 40 of balls 3, there is arranged in the inner shaft 1 a concave portion in the form of an axial groove 101 whose section comprises two curved faces 103, 104 inclined relative to each other, which come into contact with the beads 3.

For each row 40 of balls 3, there is arranged in the outer shaft 2 a concave portion in the form of an axial groove 102 whose section comprises a bottom 105 and two sides 106 and 107. The bottom 105 is substantially perpendicular to the diametral plane passing through. by his environment.

For each row 40 of balls 3, there are two raceways 110, which are arranged in the concave portion in the form of an axial groove 102 of the outer shaft 2. Each raceway 110 is in the form of an axial bar. The section of each raceway 110 has a concave face 111 which comes into contact with the balls 3, two contiguous faces 113 and 112 relative to each other, and which are respectively arranged opposite the bottom 105. and one of the flanks 106 or 107 of the axial groove 101, a bead 114 is arranged on the face 113 at the angle of the face 112.

For each row 40 of balls 3, there is an elastic element, in the form of an elastic axial coil 97, the section of which has an axial base 98 and two axial protuberances 99. Said elastic axial strip 97 is disposed in the axial groove 102 between the The axial base 98 bears against the bottom 105 of the axial groove 102, so that each of the two axial protuberances 99 pushes the corresponding raceway 110.

In the embodiment shown in Figure 10, the balls 3 are arranged in three axial rows 40. The axial rows 40 are located transverse to 120 from each other. The balls 3 of each axial row 40 are held in place relative to one another by a cage 128. There are therefore three cages 128.

For two of the three rows 40 of balls 3, there is arranged in the outer shaft 2 a concave portion in the form of an axial groove 122 whose section comprises two curved faces 123 and 124 inclined with respect to each other, which come into contact with the balls 3.

For each row 40 of balls 3, there is arranged in the inner shaft 1 a concave portion in the form of an axial groove 121 whose section comprises a bottom 125 and two flanks <B> 126 </ B> and 127. The bottom 125 is substantially perpendicular to the diametral plane passing through its middle.

For each row 40 of balls 3, there are two races 130, which are arranged in the concave portion in the form of an axial groove 121 of the inner shaft 1. Each raceway 130 is in the form of an axial bar, of which the section has a curved shape 131 in order to come into contact with the balls 3. Each raceway 130 has two folded ends 132 and 133.

For each row 40 of balls 3, two elastic elements, in the form of elastic axial flange 134, are arranged in the axial groove 121. Each elastic element 134 bears on the bottom 125 and on one of the flanks 126 or 127 of the axial groove 121 to push on the corresponding raceway 130.

In the embodiment of Figure 11, the balls 3 are arranged in two axial rows 40. The axial rows 40 are located transversely diametrically opposite. The balls 3 of each axial row 40 are held in place relative to each other by a cage 128. There are therefore two cages 128.

In the description below, each row of balls 40 relates to the third row of balls not described in FIG. 10, as well as to the two rows of balls of FIG. 11.

For each row 40 of balls 3, there is arranged in the inner shaft 1 a concave portion in the form of an axial groove 141 whose section comprises two curved faces 143, 144 inclined relative to each other, which come into contact with the beads 3.

For each row 40 of balls 3, there is arranged in the outer shaft 2 a concave portion in the form of an axial groove 142 whose section comprises a bottom 145 and two sides 146 and 147. The bottom 145 is substantially perpendicular to the diametral plane passing through. by his environment.

For each row 40 of balls 3, there are two raceways 130, which are arranged in the concave portion in the form of an axial groove 142 of the outer shaft 2. Each raceway 130 is in the form of an axial bar, of which the section has a curved shape 131 in order to come into contact with the balls 3. Each raceway 130 has two folded ends 132 and 133.

For each row 40 of balls 3, two elastic elements in the form of elastic axial flange 134 are arranged in the axial groove 142. Each elastic element 134 bears on the bottom 145 and on one of the flanks 146 or 147 of the groove axial 142, to push on the corresponding raceway 130.

As can be seen in FIG. 12, male grooves 34 and female grooves 35, having conjugate profiles with a certain clearance, are arranged on the inner shaft 1 and the outer shaft 2. Thus, in case of rupture 3, the torque can still be transmitted between the inner shaft 1 and the outer shaft 2.

According to the invention, and whatever the embodiment of the elastic elements, the elastic elements 57, 97 or 131 are arranged. either in the inner shaft 1, or in the outer shaft 2, or for some in the inner shaft 1, and for the others in the outer shaft 2.

In addition, irrespective of the construction of the elastic elements, the balls 3 may be arranged in several axial rows 40, and in particular in two diametrically opposed axial rows 40, or in three axial rows 40 arranged transversely to each other.

In the embodiment shown in Figures 3 and 4, the inner shaft 1 is provided with three axial grooves 41. The axial grooves 41 are transverse to 120 from each other. In each axial groove 41 are mounted an elastic element in the form of elastic axial coil 57 and two raceways 50 in the form of axial bar.

The balls 3 are arranged in three axial rows 40, the axial rows are transversely 120 from each other. The balls are held in place relative to one another by a sleeve-shaped cage 43.

The assembly of the sleeve 43 with balls 3 with the raceways 50 and the elastic axial strands 57 is closed at each axial end by a retaining ring 151 and 152. Each retaining ring 151 and 152 is engaged to the using pins 153 and 154 in each of the axial grooves 41 of the inner shaft 1. One of the retaining rings 151 bears against a rod 155, which is mounted in a groove 156 of the inner shaft 1.

The outer shaft 2 is provided with three axial grooves 42 transverse to 120 from each other. The axial grooves 42 slide on the rows 40 of balls 3. The axial grooves 42 have the desired length to allow the axial sliding required of the outer shaft 2 and the inner shaft 1.

The assembly of FIGS. 3 and 4 can also be applied in particular to the axial grooves 81 and 82 with the raceways 90 and the elastic axial tubes 97.

Claims (1)

1 - Device for coupling two shafts, an inner shaft (1) and an outer shaft (2) which slide in one another in the direction of their common axis (4), said coupling device of the two shafts two shafts comprises rolling elements 3, which are arranged between the inner shaft (1) and the outer shaft (2), the coupling device is characterized in that - each of said rolling elements (3) is arranged: on the one hand in a concave part (17) of the inner shaft (1), and. on the other hand in a concave portion (16) of the outer shaft (2); each of said rolling elements (3) is provided with at least one elastic element (22, 23, 25) which is arranged between said rolling element (3) and the corresponding concave part (17) of one of the two shafts ( 1, 2); - so that at rest, when there is no torque transmission, each rolling element (3) is always in contact on the side of the elastic element (s), and on the side opposite; and so that when there is torque transmission, there is for each rolling element (3), at least one bearing zone on the side of the elastic element (s), and least one support zone on the opposite side. 2 - Coupling device according to claim 1, characterized in that the rolling elements are balls (3). 3 - Coupling device according to claim 2, characterized in that each of the balls (3) is provided with two elastic elements (22, 23) which are arranged between the corresponding concave portion (17) and said ball (32). 4 - Coupling device according to claim 2, characterized in that each of the balls (3) is provided with three elastic elements (22, 23, 25) which are arranged between the corresponding concave part (17) and said ball (3 ). 5 - Coupling device according to any one of the preceding claims, characterized in that each of the elastic elements is a spring (22, 23, 25) with a bearing pad (24, 26, 27) against the ball ( 3) corresponding. 6 - Coupling device according to claim 2, characterized in that each of the balls (3) moves on two raceways (50, 70, 90, 110) which are pushed against said ball (3) by the same element elastic (57, 97) corresponding; said raceways (50, 70, 90, 110) being disposed between said ball (3) and the corresponding elastic member (57, 97). 7 - Coupling device according to claim 2, characterized in that each of the balls (3) moves on two races (130) with two elastic elements (134), each of the raceways (130) is pushed against said ball (3) by the corresponding elastic element (134), each of said raceways (130) is disposed between said ball (3) and the corresponding elastic element (134). 8 - Coupling device according to any one of the preceding claims, characterized in that the balls (3) are arranged in at least one holding cage (43, 128). 9 - Coupling device according to any one of the preceding claims, characterized in that male grooves (34) and females (35) with conjugate profiles having a certain clearance, are arranged on the inner shaft (1) and the outer shaft (2), so that in case of breakage of the balls (3), the torque can still be transmitted between the inner shaft (1) and the outer shaft (2). 10 - Coupling device according to any one of the preceding claims, characterized in that the element (s) elastic (s) (57, 97, 131) is / are arranged (s) in the inner shaft ( 1). 11 - Coupling device according to any one of claims 1 to 9, characterized in that the or the elastic elements (57, 97, 134) is / are arranged (s) in the outer shaft (2). 12 - Coupling device according to any one of claims 1 to 9, characterized in that the elastic elements (57, 97, 134) are arranged for some in the inner shaft (1), and for others in the outer shaft (2). 13 - Coupling device according to claim 6, characterized in that the balls (3) are arranged in several axial rows (40); the balls (3) being held in place relative to one another by a cage (43). - For each row (40) of balls (3), there is arranged in the outer shaft (2) a concave portion in the form of axial groove (42), the section has two concave faces (44, 45) inclined l one with respect to the other, which come into contact with the balls (3); - for each row (40) of balls (3), is arranged in the inner shaft (1) a concave portion in the form of axial groove (41), the section comprises a bottom (46) and two flanks (47). , 48), the bottom (46) being substantially perpendicular to the diametral plane passing through its middle; - for each row (40) of balls (3), two raceways (50) are arranged in the concave portion in the form of an axial groove (41) of the inner shaft (1), each raceway (50) is in the form of an axial bar, the section of which has a concave face (51) which comes into contact with the balls (3), two contiguous faces (53, 52) relative to each other, and which are respectively disposed opposite the bottom (46) and one of the flanks (47, 48) of the axial groove (41), a inclined face (54) with respect to the bottom (46) of the axial groove (41); - for each row (40) of balls (3), a resilient, elastic axial coil-shaped element (57) whose section is circular is arranged in the axial groove (41) between the two raceways (50), said elastic axial flange (57) bearing on the bottom (46) of the axial groove (41), to push the inclined face (54) of each of the two races (50). 14 - Coupling device according to claim 6, characterized in that the balls (3) are arranged in several axial rows (40), the balls (3) being held in place relative to each other by a cage (43). ). - for each row (40) of balls (3), there is arranged in the inner shaft (1) a concave portion in the form of an axial groove (61), whose section comprises two concave faces (63, 64) inclined l one with respect to the other, which come into contact with the balls (3); - for each row (40) of balls (3), there is arranged in the outer shaft (2) a concave portion in the form of an axial groove (62) whose section comprises a bottom (65) and two sidewalls (66, 67), the bottom (65) being substantially perpendicular to the diametral plane passing through its middle; - for each row (40) of balls (3), two raceways (70) are arranged in the concave portion in the form of an axial groove (62) of the outer shaft (2), each raceway (70) is in the form of an axial bar, the section of which has a concave face (71) which comes into contact with the balls (3), two contiguous faces (73, 72) relative to one another, and which are respectively arranged opposite the bottom (65) and one of the flanks (66, 67) of the axial groove (62), a inclined face (74) with respect to the bottom (65) of the axial groove (62); - for each row (40) of balls (3), an elastic element, in the form of an elastic axial coil (57) whose section is circular, is disposed in the axial groove (62) between the two raceways (70) , said elastic axial flange (57) bearing on the bottom (65) of the axial groove (62), to push the inclined face (74) of each of the two raceways (70). 15 - Coupling device according to claim 6, characterized in that the balls (3) are arranged in several axial rows (40), the balls (3) being held in place relative to each other by a cage (43). ). - For each row (40) of balls (3), there is arranged in the outer shaft (2) a concave portion in the form of an axial groove (82) whose section comprises two concave faces (83, 84) inclined the one with respect to the other, which come into contact with the balls (3); for each row (40) of balls (3), there is arranged in the inner shaft (1) a concave portion in the form of an axial groove (81) whose section comprises a bottom (85) and two sidewalls (86, 87), the bottom (85) being substantially perpendicular to the diametral plane passing through its middle; - for each row (40) of balls (3), two races (90) are arranged in the concave portion in the form of an axial groove (81) of the inner shaft (1), each raceway (90) is in the form of an axial bar, whose section a. a concave face (91) which comes into contact with the balls (3), two contiguous faces (93, 92) relative to one another, and which are respectively disposed opposite the bottom (85) and one of the flanks (86, 87) of the axial groove (81),. a bead (94) is arranged on the face (93) at the corner of the face (92); - For each row (40) of balls (3), an elastic element, in the form of elastic axial coil (97) whose section has an axial base (98) and two axial protuberances (99), said elastic axial coil (97) ) is arranged in the axial groove (81) between the beads (94) of the two races (90), the axial base (98) resting on the bottom (85) of the axial groove (81), so as to that each of the two axial protuberances (99) pushes the corresponding raceway (90). 16 - Coupling device according to claim 6, characterized in that the balls (3) are arranged in several axial rows (40), the balls being held in place relative to each other by a cage (43). - For each row (40) of balls (3), there is arranged in the inner shaft (1) a concave portion in the form of axial groove (101) whose section comprises two curved faces (103, 104) inclined the one with respect to the other, which come into contact with the balls (3); - for each row (40) of balls (3), there is arranged in the outer shaft (2) a concave portion in the form of an axial groove (102) whose section comprises a bottom (105) and two sidewalls (106, 107), the bottom (105) being substantially perpendicular to the diametral plane passing through its middle - for each row (40) of balls (3), two raceways (110) are arranged in the concave portion in the form of an axial groove ( 102) of the outer shaft (2), each raceway (110) is in the form of an axial bar, whose section has a concave face (111) which comes into contact with the balls (3), two contiguous faces ( 113, 112) relative to each other, and which are respectively disposed opposite the bottom (105) and one of the flanks (106, 107) of the axial groove (101), a bead (114). is arranged on the face (113) at the corner of the face (112); - For each row (40) of balls (3), an elastic element, in the form of elastic axial coil (97) whose section has an axial base (98) and two axial protuberances (99), said elastic axial coil (97) ) is arranged in the axial groove (102) between the beads (114) of the two raceways (110), the axial base (98) resting on the bottom (105) of the axial groove (102), so as to that each of the two axial protuberances (99) pushes the corresponding raceway (110). 17 - Coupling device according to claim 7, characterized in that the balls (3) are arranged in several axial rows (40), the balls (3) of each axial row (40) being held in place relative to one another. to others by a cage (128); - for each row (40) of balls (3), there is arranged in the outer shaft (2) a concave portion in the form of an axial groove (122) whose section comprises two curved faces (123, 124) inclined the relative to one another, which come into contact with the balls (3) - for each row (40) of balls (3), a concave portion in the form of an axial groove is arranged in the inner shaft (1) (121) whose section comprises a bottom (125) and two flanks (126, 127), the bottom (125) being substantially perpendicular to the diametral plane passing through its middle; - for each row (40) of balls (3), two raceways (130) are arranged in the concave portion in the form of an axial groove (121) of the inner shaft (1), each raceway (130) is in the form of an axial bar, the section of which has a curved shape in order to come into contact with the balls (3); - For each row (40) of balls (3), two elastic elements, in the form of elastic axial flange (134), are arranged in the axial groove (121), each elastic element (134) resting on the bottom ( 125) and on one of the flanks (126, 127) of the axial groove (121) to push on the corresponding raceway (130). 18 - Coupling device according to claim 7, characterized in that the balls (3) are arranged in several axial rows (40), the balls (3) of each axial row (40) being held in place relative to each other. to others by a cage (128); - for each row (40) of balls (3), there is arranged in the inner shaft (1) a concave portion in the form of an axial groove (141) whose section comprises two curved faces (143, 144) inclined the one with respect to the other, which come into contact with the balls (3); - for each row (40) of balls (3), there is arranged in the outer shaft (2) a concave portion in the form of an axial groove (142) whose section comprises a bottom (145) and two sidewalls (146, 147), the bottom (145) being substantially perpendicular to the diametral plane passing through its middle; - for each row (40) of balls (3), two raceways (130) are arranged in the concave portion in the form of an axial groove (142) of the outer shaft (2), each race (130). is in the form of an axial bar, the section of which has a curved shape in order to come into contact with the balls (3), - for each row (40) of balls (3), two resilient elements in the form of an elastic axial coil (134) ) are arranged in the axial groove (142), each elastic element (134) bearing on the bottom (145) and on one of the flanks (146, 147) of the axial groove (142), in order to push on the corresponding raceway (130). 19 - Coupling device according to any one of claims 13 to 18, characterized in that the balls (3) are arranged in three axial rows (40), the axial rows (40) being transverse to 120 from each other - The inner shaft (1) is provided with three axial grooves (41, 81, 12l), the axial grooves (41, 81, 121) being transverse to 120 from each other; - The outer shaft (2) is provided with three axial grooves (42, 82, 122), the axial grooves (42, 82, 122) being transverse to 120 from each other. 20 - Coupling device according to any one of claims 13 to 18, characterized in that - the balls (3) are arranged in two axial rows (40) diametrically opposite; - The inner shaft (1) is provided with two axial grooves (41, 81, 121) diametrically opposed; - The outer shaft (2) is provided with two axial grooves (42, 82, 122) diametrically opposed. 21 - Coupling device according to any one of claims 13 and 15, characterized in that - the inner shaft (1) is provided with three axial grooves (41, 81), the axial grooves (41, 81) being transversely to each other, in each axial groove (41, 81) are mounted an elastic axial coil-shaped resilient member (57, 97) and two axial bar-shaped raceways (50, 90); - The balls (3) are arranged in three axial rows, the axial rows being transverse to 120 from each other, the balls being held in place relative to each other by a sleeve-shaped cage; - the whole of the sleeve (43) ball (3) with the raceways (50, 90) and the elastic axial strands (57, 97) is closed at each axial end by a retaining ring (151, 152) which engages in each of the axial grooves (41, 81) of the inner shaft (1), one of the retaining rings (15l) pressing against a rod (l55) which is mounted in a groove ( 156) of said inner shaft (1); - The outer shaft (2) is provided with three axial grooves (42, 82) transverse to each other 120, which slide on the rows (40) of balls (3), the axial grooves (42, 82). having the desired length to allow the requested axial sliding of the outer shaft (2) and the inner shaft (1). 22 - Coupling device according to any one of the preceding claims, characterized in that it applies to the intermediate portion (7) of a steering column of a motor vehicle. 23 - Coupling device according to any one of claims 1 to 20, characterized in that it applies to the upper part of a steering column of a motor vehicle.