US20040116192A1

US20040116192A1 - Homocinetic fixed joint

Info

Publication number: US20040116192A1
Application number: US10/433,638
Authority: US
Inventors: Werner Krude; Peter Harz
Original assignee: Individual
Current assignee: GKN Driveline International GmbH
Priority date: 2000-12-04
Filing date: 2001-11-21
Publication date: 2004-06-17
Also published as: WO2002046631A1; JP2009109021A; US7607985B2; DE10060220A1; JP5023081B2; US20060142089A1; US20090062022A1; DE10060220C2; AU2002224866A1; JP2004518083A; US7462107B2

Abstract

A constant velocity fixed joint having the following characteristics:

an outer joint part comprises a first longitudinal axis and an attaching part and an aperture which are axially opposed relative to one another, as well as outer ball tracks;

an inner joint part comprises a second longitudinal axis and inner ball tracks;

the track base lines of the pairs of tracks each form an opening angle relative to one another which opens from the aperture to the attaching part;

the track base lines of the outer ball tracks of the pairs of tracks, at the attaching part end, form a radius whose centre is positioned on the first longitudinal axis and is offset by a first offset OFF₁from the central plane of the outer joint part towards the attaching part, and move away from a circle with said radius outwardly towards the aperture end;

the track base lines of the inner ball tracks of the pairs of tracks, at the aperture end, comprise a radius whose centre is positioned on the second longitudinal axis and is offset by a second offset OFF₂from the central plane of the inner joint part towards the aperture, and move away from a circle with said radius outwardly towards the attaching part end.

Description

DESCRIPTION

The invention relates to the field of constant velocity universal joints and comprises a type of joints which will be explained in greater detail below. In principle, such joints comprise an outer joint part with an aperture and an attaching part, an inner joint part into which there is inserted a shaft which emerges from the aperture, torque transmitting balls guided in pairs of tracks in the outer joint part and in the inner joint part, as well as a ball cage which holds the balls in a central plane when the joint is in the aligned condition and in an angle-bisecting plane when the joint is articulated. The angle of articulation of the joint is normally delimited by the shaft stopping against the outer edge of the aperture of the outer joint part.

With a view to achieving the largest possible angle of articulation, it has been found that those joints are advantageous which comprise pairs of tracks whose opening angle opens from the attaching part towards the joint aperture, i.e. whose track base lines diverge from one another if viewed in said direction. However, such joints are disadvantageous in respect of the strength of the joint. The invention does not deal with such a type of joints.

As far as the joint strength is concerned, those joints with pairs of tracks whose opening angle opens from the joint aperture to the attaching part, i.e. wherein the base track lines diverge from one another if viewed in said direction, are more advantageous. It is joints of this type which are the subject of the present invention.

There is a prior art first group of said joints wherein all pairs of track have such characteristics. In such joints, the strength of the outer joint part is greatly improved, but the load on the ball cage continues to be unchanged and high.

In addition, there is a prior art second group of such joints wherein only some of the pairs of tracks have such characteristics. In such joints, the strength of the outer joint part has been improved and the load on the ball cage has been reduced.

As compared to the joints mentioned first, the strength of both said groups of joints has been improved, but there are limitations as far as the angle of articulation is concerned.

It is the object of the present invention to achieve greater angles of articulation in joints of said type. The objective is achieved by the design, in accordance with the invention, of the pairs of tracks which open towards the attaching side and, respectively, the attaching part, which design is defined in the various independent claims.

The species of joints to which the invention can be applied can thus be defined as constant velocity fixed joints with the following characteristics. An outer joint part has a first longitudinal axis and an attaching part or attaching end and an aperture for entrance of a shaft which are axially opposed relative to one another, and outer ball tracks; an inner joint part has a second longitudinal axis and comprises inner ball tracks; the outer ball tracks have centre lines and track base lines which extend at equal distances therefrom, which are curved and extend in planes through the first longitudinal axis; the inner ball tracks have centre lines and track base lines which extend at equal distances therefrom, which are curved and extend through the second longitudinal axis; the outer ball tracks and the inner ball tracks form pairs of tracks with one another which each receive a torque transmitting ball; a ball cage is positioned between the outer joint part and the inner joint part and comprises circumferentially distributed cage windows which each receive a torque transmitting ball; the centres of the balls are held by the cage in a central plane when the joint is in an aligned condition, and when the joint is in an aligned condition, the centre lines of the pairs of tracks are mirror-symmetrical relative to one another with reference to said central plane; the track base lines of the pairs of tracks form an opening angle with one another, i.e. they diverge from one another. A first group of joints only comprises pairs of tracks whose track base lines diverge from one another running from the aperture to the attaching part, i.e whose opening angle opens from the aperture towards the attaching end/attaching part; such so-called UFA joints are shown in FIGS. 1 and 2; a second group of joints on the other hand only at one part of the pairs of tracks, more particularly at each second one of the pairs of tracks, if viewed across the circumference, comprises track base lines which diverge from one another from the aperture to the attaching end/attaching part, i.e. which form an opening angle which opens in said direction; such so-called UFC joints are shown in FIGS. 3 and 4.

The inventive definitions given below refer only to said inventive pairs of tracks whose opening angle widens from the aperture to the attaching end/attaching part. To the extent that there are, in addition, pairs of tracks which widen from the attaching end/attaching part towards the aperture, these do not necessarily have to comply with the definitions in accordance with the invention and can be designed to deviate therefrom. The opening angle is always the angle between the tangents at the balls in the track contact points.

According to a first solution in accordance with the invention, it is proposed that the track base lines of the outer ball tracks of the pairs of tracks, at the attaching part end, form a radius r _awhose centre is positioned on the first longitudinal axis so as to be offset by a first offset OFF₁from the central plane of the outer joint part towards the attaching part, and diverge from a circle with said radius r_aoutwardly when running towards the aperture end; whereas the track base lines of the inner ball tracks of the pairs of tracks, at the aperture end, comprise a radius r_iwhose centre is positioned on the second longitudinal axis so as to be offset by a second offset OFF₂from the central plane of the inner joint part towards the aperture and diverge from a circle with said radius r_ioutwardly when running towards the attaching part end.

According to a further basic solution it is proposed that the track base lines of the outer ball tracks of the pairs of tracks, continuously, comprise a radius r _awhose centre is positioned beyond the first longitudinal axis and offset by a first offset OFF₁′ from the central plane of the outer joint part towards the attaching part, whereas the track base lines of the inner ball tracks of the pairs of tracks, continuously, comprise a radius r_iwhose centre is positioned beyond the second longitudinal axis and offset by a second offset OFF₂′ from the central plane of the inner joint towards the aperture.

According to a third basic possibility it is proposed that the track base lines of the outer ball tracks of said pairs of tracks, at the attaching part end, comprise a radius r _awhose centre is positioned beyond the first longitudinal axis and offset by a first offset OFF₁′ from the central plane of the outer joint part towards the attaching part, and diverge from a circle with said radius r_aoutwardly when running towards the aperture end, whereas the track base lines of the inner ball tracks of the pairs of tracks comprise a radius r_iwhose centre is positioned beyond the second longitudinal axis and offset by a second offset OFF₂′ from the central plane of the inner joint part towards the aperture, and diverge from a circle with said radius r_ioutwardly when running towards the attaching part end.

According to special embodiments of the first and third solutions, it is proposed that the track base lines each consist of a circular-arch-shaped portion with the radius r _a, r_iand a tangentially adjoining straight line portion. According to a further embodiment, the track base lines each consist of a circular-arch-shaped portion with the radius r_a, r_iand a tangentially adjoining second circular-arch-shaped portion with the radius R_ae, R_iewhich is greater than the radius r_a, r_i. According to a further modification, the track base lines can each consist of a circular-arch-shaped portion with the radius r_a, r_iand a circular-arch-shaped portion with the radius r_1a, r_1icurved in the opposite direction, and a tangentially adjoining straight line. According to a further embodiment, the track base lines can each consist of a circular-arch-shaped portion with the radius r_a, r_i, a tangentially adjoining straight line portion, a circular-arch-shaped portion curved in the direction opposite to that of the portion and having the radius r_1a, r_1i, and a tangentially adjoining straight line.

The joint strength in the outer joint part is increased because the apex of the track curvature of the outer ball tracks is far removed from the aperture, whereas the joint articulation angle is relatively increased due the outer ball tracks development towards the aperture.

Preferred embodiments of inventive joints will be explained in greater detail below with reference to the drawings wherein [0015]
FIG. 1 shows a first embodiment of a joint according to the state of the art wherein all pairs of tracks diverge from the joint aperture towards the attaching part. [0016]
FIG. 2 shows a second embodiment of a joint according to the state of the art wherein all pairs of tracks diverge from the joint aperture to the attaching part. [0017]
FIG. 3 shows a first embodiment of a joint according to the state of the art wherein some of the pairs of tracks diverge from the joint aperture to the attaching part. [0018]
FIG. 4 shows a second embodiment of a joint according to the state of the art wherein some of the pairs of tracks diverge from the joint aperture to the attaching part. [0019]
FIG. 5 shows the joint according to the state of the art according to FIG. 4 in an articulated condition. [0020]
FIG. 6 shows a joint similar to that of FIG. 4 in accordance with the invention in an articulated condition. [0021]
FIG. 7 shows an inventive joint in a half-section in a second embodiment. [0022]
FIG. 8 shows an inventive joint in a half-section in a third embodiment. [0023]
FIG. 9 shows an inventive joint in a half-section in a fourth embodiment. [0024]
FIG. 10 shows an inventive joint in a half-section in a fifth embodiment. [0025]
FIG. 11 shows an inventive joint in a half-section in a sixth embodiment. [0026]
FIG. 12 shows an inventive joint in a half-section in a seventh embodiment.[0027]
FIG. 1 shows a constant velocity universal joint [0028] 11 with an outer joint part 12 which is in two parts and at which it is possible to identify an annular part 13, an attaching part 14 and a journal 15. The annular part 13 forms a joint aperture 16. Inside the annular part there are provided outer ball tracks 17 which extend into the attaching part 14. In the outer joint part 12, there is positioned an inner joint part 22 into which there is inserted a shaft 23. Inner ball tracks 24 are provided at the inner joint part 22. The outer joint part 12 comprises an inner spherical guiding face 18 in the annular part and a complementary guiding face portion 19 in the attaching part. The inner joint part 22 comprises an outer spherical guiding face 25. Between the inner guiding face 18 and the outer guiding face 25 there is positioned a ball cage 29 which comprises spherical sliding faces 30, 31 which cooperate with the guiding faces. The ball cage comprises circumferentially distributed cage windows 32 which each accommodate a ball 35. The balls each engage pairs of tracks which are formed of outer ball tracks 17 and inner ball tracks 24. A central plane E which extends through the ball centres and which is positioned perpendicularly on the axes L₁₂, L₂₂, by means of its point of intersection with the axes, defines the joint centre M. The track base lines G₁₂, G₂₂of the ball tracks 17, 24 diverge from one another from the aperture 16 to the attaching part 14. The track centre lines S₁₂, S₂₂are substantially formed by circular arches with adjoining tangents whose centres are positioned on the axes L₁₂, L₂₂and are offset in opposite directions relative to the joint centre M. A refers to the axial distance between the joint centre M and the point of contact of the ball 35 with the outer ball track 17 in the outer joint part 12 at the maximum articulation angle of the joint and B refers to the radial distance between the axis L₁₂and said point of contact of the ball 35 with the outer ball track 17 in the outer joint part 12 at the maximum articulation angle. The maximum articulation angle of the joint is determined by the shaft stopping at the outer joint part and by the end of the effective guidance of the ball 35 in the outer ball track 17 in the outer joint part 12. In the joint shown here with a round cross-sectional track shape, the point of contact is located in the track base; in joints with other cross-sectional track shapes, it is possible for pairs of contact points to be positioned opposite one another in the track flanks. The joint can comprise an even or uneven number of pairs of tracks which are identical across the circumference and which look like the pair of tracks shown in section.
FIG. 2 shows a constant velocity universal joint [0029] 11′ having an outer joint part 12′ which is in two parts and at which it is possible to identify an annular part 13′, an attaching part 14′ and a journal 15′. The annular part 13′ forms a joint aperture 16′. Inside the annular part there are formed outer ball tracks 17′. In the outer joint part 12′, there is positioned an inner joint part 22′ which is followed by an integrally formed-on shaft 23′. The inner joint part 22′ is provided with inner ball tracks 24′. The outer joint part 12′ comprises an inner spherical guiding face 18′ in the annular part and a guiding face 19′ in the attaching part. The inner joint part 22′ comprises an outer spherical guiding face 25′. A first guiding region of the guiding face 25′ is in direct contact with the guiding face 18′. Between the inner guiding face 19′ and a second guiding region of the outer guiding face 25′, there is positioned a semi-dish-shaped ball cage 29 comprising spherical sliding faces 30′, 31′ which cooperate with the guiding faces. By means of a cage edge 32′, the ball cage supports the balls 35′. The balls each engage pairs of tracks which are formed of outer ball tracks 17′ and inner ball tracks 24′. A plane E which extends through the ball centres and which is positioned perpendicularly on the axes L₁₂, L₂₃, by means of its point of intersection with said axes, defines the joint centre M. The track base lines G₁₂, G₂₂of the ball track 17′, 24′ diverge from one another from the aperture 16′ to the attaching part 14′. The track centre lines S₂₁, S₂₂are formed substantially by circular arches with adjoining tangents, whose centres are positioned on the axes L₁₂, L₂₃and are offset in opposite directions relative to the joint centre M. A refers to the axial distance between the joint centre M and the point of contact of the ball 35′ with the outer ball track 17′ in the outer joint part 12′ at the maximum joint articulation angle and B refers to the radial distance between the axis L₁₂and said point of contact of the ball 35′ with the outer ball track 17′ in the outer joint part 12′ at the maximum joint articulation angle. The maximum articulation angle of the joint is determined by the shaft stopping against the outer joint part 12′ and by the end of the effective guidance of the ball 35′ in the outer ball track 17′ in the outer joint part 12′. In the joint shown here with a round cross-sectional track shape, the point of contact is located in the track base; in joints with other cross-sectional track shapes, it is possible for pairs of contact points to be positioned opposite one another in the track flanks. The joint can comprise an even or uneven number of pairs of tracks which are identical around the circumference and which look like the pair of tracks shown in section.
FIG. 3 shows a joint [0030] 41 whose outer joint part 42 is composed of an annular part 43 and an attaching part 44. The attaching part 44 comprises an integrally attached journal 45. The annular part 43 and the attaching part 44 are connected to one another by a friction weld 50. In the outer joint part there is arranged an inner joint part 52. Between the outer joint part 42 and the inner joint part 52, there is positioned a ball cage 59 with circumferentially distributed cage windows 62 in which there are received balls 65. The outer joint part and inner joint part form first pairs of tracks consisting of outer ball tracks 47 and inner ball tracks 54 whose track base lines G₄₂, G₅₂diverge from the joint aperture 46 to the attaching part 44, as well as second pairs of tracks consisting of outer ball tracks 49 and inner ball tracks 56 whose track base lines G₄₂, G₅₂diverge from the attaching part 44 to the joint aperture 46. The centre lines S_42′, S_52′, S₄₂, S₅₂, of the ball tracks each consist of circular arches with adjoining tangents, whose centres are positioned on the axes L₄₂, L₅₂so as to be offset in opposite directions from the joint centre M. A refers to the axial distance between the joint centre M and the point of contact of the ball 65 with the outer ball track 47 in the outer joint part 42 at the maximum joint articulation angle and B refers to the radial distance between the axis L₄₂and said point of contact of the ball 65 with the outer ball track 47 in the outer joint part 42 at the maximum joint articulation angle. The maximum articulation angle of the joint is determined by the shaft stopping against the outer joint part 42 and by the end of the effective guidance of the ball 65 in the outer ball track 47 in the outer joint part 42. In the joint shown here with a round cross-sectional track shape, the point of contact is located in the track base; in joints with other cross-sectional track shapes, it is possible for pairs of contact points to be positioned opposite one another in the track flanks. The two different pairs of tracks can be arranged so as to alternate on the circumference or they can be alternately distributed in pairs.
FIG. 4 shows a joint [0031] 41′ whose outer joint part 42′ is composed of an annular part 43′ and an attaching part 44′. The attaching part 44′ comprises an integrally attached journal 45′. The annular part 43′ and the attaching part 44′ are produced so as to be integral with one another. In the outer joint part 42′ there is arranged an inner joint part 52′. Between the outer joint part 42′ and the inner joint part 52′, there is positioned a ball cage 59′ with circumferentially distributed cage windows 62′ in which there are received balls 65′. The outer joint part and inner joint part form first pairs of tracks consisting of outer ball tracks 47′ and inner ball tracks 54′ whose track base lines G_42′, G_52′diverge from the joint aperture 46′ to the attaching part 44′, as well as second pairs of tracks consisting of outer ball tracks 49′ and inner ball tracks 56′ whose track base lines G₄₂, G₅₂diverge from the attaching part 44′ to the joint aperture 46′. The centre lines S_42′, S_52′, S₄₂, S₅₂, of the ball tracks each consist entirely of circular arches whose centres are positioned on the axes L₄₂, L₅₂so as to be offset in opposite directions from the joint centre M. A refers to the axial distance between the joint centre M and the point of contact of the ball 65′ with the outer ball track 47′ in the outer joint part 42′ at the maximum joint articulation angle and B refers to the radial distance between the axis L₄₂and said point of contact of the ball 65′ with the outer ball track 47′ in the outer joint part 42′ at the maximum joint articulation angle. The maximum articulation angle of the joint is determined by the shaft stopping against the outer joint part 42′ and by the end of the effective guidance of the ball 65′ in the outer ball track 47′ in the outer joint part 42′. In the joint shown here with a round cross-sectional track shape, the point of contact is located in the track base; in joints with other cross-sectional track shapes, it is possible for pairs of contact points to be positioned opposite one another in the track flanks. The two different pairs of tracks can be arranged so as to alternate on the circumference or they can be alternately distributed in pairs.
FIG. 5 shows the joint according to FIG. 4 in accordance with the state of the art in an articulated condition. The axis L[0032] ₅₂of the inner joint part 52′, together with the axis L₄₂of the outer joint part 42′, forms an angle a which is delimited in that the shaft 53′ stops against the aperture 46′ of the outer joint part. The point of intersection of the axes L₄₂, L₅₂is positioned in the joint centre M. The centre lines S_42′, s_52′, S₄₂, S₅₂of all outer and inner ball tracks 47′, 54′, 49′, 56′ are formed by circular arches whose centres are arranged on the respective axis L₄₂, L₅₂of the respective joint part 42′, 52′ so as to be offset in opposite directions from the central plane of the respective joint part 42′, 52′. The track centre lines, in turn, form pairs of points of intersection which constitute the geometric locations for the centres of the balls 65′. A refers to the axial distance between the joint centre M and the point of contact of the ball 65′ with the outer ball track 47′ in the outer joint part 42′ at the maximum joint articulation angle and B refers to the radial distance between the axis L₄₂and said point of contact of the ball 65′ with the outer ball track 47′ in the outer joint part 42′ at the maximum joint articulation angle. The maximum articulation angle of the joint is determined by the shaft stopping against the outer joint part 42′ and by the end of the effective guidance of the ball 65′ in the outer ball track 47′ in the outer joint part 42′. These dimensions, together with the diameter d of the shaft 53′, result in the maximum articulation angle of α=45°. In the joint shown here with a round cross-sectional track shape, the point of contact is located in the track base; in joints with other cross-sectional track shapes, it is possible for pairs of contact points to be positioned opposite one another in the track flanks.
FIG. 6 shows a joint similar to that shown in FIG. 4 in accordance with the invention in an articulated condition. The axis L[0033] ₅₂of the inner joint part 52 ₆, together with the axis L₄₂of the outer joint part 42 ₆, forms an angle α₁which is delimited in that the shaft 53 ₆stops against the aperture 46 ₆of the outer joint part. The point of intersection of the axes L₄₂, L₅₂is positioned in the joint centre M. The centre lines S_42′, S_52′, of the outer and inner ball tracks 49 ₆, 56 ₆are formed entirely by circular arches with adjoining tangents, whose centres are arranged on the respective axis of the respective joint part 42 ₆, 52 ₆so as to be offset in opposite directions relative to the joint centre M. The track centre lines, in turn, form pairs of points of intersection with one another, which constitute the geometric locations for the centres of the balls 65 ₆. A refers to the axial distance between the joint centre M and the point of contact of the ball 65 ₆with the outer ball track 47 ₆in the outer joint part 42 ₆at the maximum joint articulation angle and B refers to the radial distance between the axis L₄₂and said point of contact of the ball 65 ₆with the outer ball track 47 ₆in the outer joint part 42 ₆at the maximum joint articulation angle. The maximum articulation angle of the joint is determined by the shaft stopping against the outer joint part 42 ₆and by the end of the effective guidance of the ball 65 ₆in the outer ball track 47 ₆in the outer joint part 42 ₆. These dimensions, together with the diameter d of the shaft 53 ₆, result in the maximum articulation angle of α₁=47°. In the joint shown here with a round cross-sectional track shape, the point of contact is located in the track base; in joints with other cross-sectional track shapes, it is possible for pairs of contact points to be positioned opposite one another in the track flanks.
When comparing the state of the art joint of FIG. 5 with the inventive joint according to FIG. 6 it has to be pointed out that the angle α[0034] ₁is greater than the angle α. This has been achieved by said change in the track centre lines, which is accompanied by an increase in the dimension B and a decrease in the dimension A.
The subsequent FIGS. [0035] 7 to 12 each show only part of an outer joint part 12, 42 in various embodiments, with an outer ball track 17, 47 which opens towards the attaching part. In all variants, the opening dimension B has been increased relative to the state of the art, whereas the axial dimension A has been reduced relative to the state of the art. In the half-section, the fixed outer joint part with a horizontal axis and the inner joint part which, relative thereto, has been pivoted towards the left by the angle a are shown in continuous lines. The ball cage is not shown. Furthermore, thin lines show the shaft 23, 53 in a stopping position at the joint aperture 16, 46, pivoted to the right by the angle α, as well as a ball 35, 65 which, together with the inner joint part, has been pivoted towards the left by the angle α/2. The shaft 23, 53 and ball 35, 65 drawn inside one another thus, in fact, are positioned on diametrically opposite sides of the axis L₄₂.
In all Figures, M refers to the joint centre and Z[0036] ₁and Z2 refer to centres of the generating radii of curvature of the tracks, which centres are positioned on the axes L₁₂, L₂₂, L₄₂, L₅₂, so as to be offset from the joint centre M in opposite directions. The position of the centres Z₁and Z₂in the direction of the axes is indicated by an axial offset OFF₁from the central plane E₁₂, E₄₂of the outer joint part and by an axial offset OFF₂from the central plane E₂₂, E₅₂of the inner joint part. The angle-bisecting plane has been given the reference symbol E′.
Hereafter, the outer ball tracks [0037] 17, 47 are described as extending from the attaching part to the aperture, whereas the inner ball tracks are described as extending from the aperture to the attaching part.
In FIG. 7, the [0038] outer ball track 17 ₇, 47 ₇in the outer joint part 22 ₇, 47 ₇is composed of a first portion S₁and a second portion S₅, with the further details referring to the track base G₁₂, G₄₂. The portion S₁, with the radius r_a, is formed round the centre Z₁and extends as far as the radial plane T₁through the centres Z₁and Z₃. The portion S₅, with the greater radius R_ae, is formed around an eccentric centre Z₃and extends from the radial plane T₁to the aperture 16 ₇, 46 ₇of the outer joint part. The inner ball track 24 ₇, 54 ₇on the inner joint part is composed of corresponding track portions, with the further details also referring to the track base G₂₂, G₅₂. A first portion, with the radius r_i, is formed around the pivoted centre Z₂′and extends as far as the radial plane T₂through the centres Z₂′ and Z₄′. A second portion, with the greater radius R_ieis formed around an eccentric centre Z₄′ and extends from the radial plane T₂to the inner end face of the inner joint part.
In FIG. 8, the [0039] outer ball track 17 ₈, 47 ₈is formed of three portions S₁, S₃and S₄. The portion S₁is defined by the radius r_aaround the centre Z₁and extends beyond the radial plane T through the centre Z₁as far as the tangentially following portion S₃. The portion S₃is defined by a counter radius with the radius r_1aand extends as far as the portion S₄. The portion S₄is a tangential straight line adjoining the radius r_1a. The inner ball track 24 ₈, 54 ₈on the inner joint part is composed of corresponding track portions. A first portion with the radius r_iis formed around the pivoted centre Z₂′. Said first portion is tangentially followed by a second portion with a counter radius r_1iwhich changes into a tangentially adjoining straight line (not described in further detail).
In FIG. 9, the [0040] outer ball track 17 ₉, 47 ₉is formed of three portions S₁, S₃and S₄. The portion S₁is defined by the radius r_aaround the centre Z₁and extends beyond the radial plane T through Z₁as far as the portion S₂. S₂is a tangential straight line which follows the portion S₁and which, together with the axis L₄₂, encloses an angle b and extends as far as the portion S₃. S₃is a counter radius with the radius r_1atangentially following S₂and extends as far as the portion S₄. S₄is a straight line tangentially adjoining S₃. The inner ball track 24 ₉, 54 ₉on the inner joint part is composed of the corresponding track portions. A first portion in form of a radius is formed around the pivoted centre Z₂′ with the radius r_i. Said first portion is followed by a straight line (not described in greater detail) in the form of a second portion which, in turn, is followed by a third portion in the form of a tangentially adjoining counter radius r_1iand by a fourth portion (not described in greater detail) in the form of a straight line.
In FIG. 10, the [0041] outer ball track 17 ₁₀, 47 ₁₀is formed by a uniform portion S₁which is defined by a radius r_aaround an eccentric centre Z₃which, on the axis L₄₂, L₁₂is at a distance OFF₁from the joint centre M. The inner ball track 24 ₁₀, 54 ₁₀is formed accordingly by a uniform portion with the radius r_iaround the pivoted eccentric centre Z₄′ which, on the axis L₂₂, L₅₂, is at a distance OFF₂from the joint centre.
In FIG. 11, the [0042] outer ball track 17 ₁₁, 47 ₁₁is formed of two portions S₁, S₂. The portion S₁is defined by a radius r_aaround a centre Z₃which corresponds to that shown in FIG. 10 and extends beyond the radial plane T₃through the centre Z₃as far as the portion S₂. The portion S₂is defined by a straight line tangentially following the portion S₁, extending at the angle b relative to the centre line L₁₂, L₄₂. The inner ball track 24 ₁₁, 54 ₁₁is formed accordingly by a first portion with the radius r_iaround the pivoted centre Z₄′ and a tangentially following straight line (not described in further detail).
In FIG. 12, the [0043] outer ball track 17 ₁₂, 47 ₁₂is formed of two portions S₁, S₂. The portion S₁is defined by a radius r_aaround a centre Z₁, which corresponds to that shown in FIG. 9 and extends beyond the radial plane T₁through the centre Z₁as far as the portion S₂. The portion S₂is defined by a straight line tangentially following the portion S₁, extending at the angle b relative to the centre line L₁₂, L₄₂. The inner ball track 24 ₁₁, 54 ₁₁is formed accordingly by a first portion in the form of a radius around the pivoted centre Z₂′ with the radius r_I, and a tangentially following straight line (not described in further detail).
As already explained, the points of contact of the ball with the outer track in track cross-sections other than round can also be positioned at a distance from the track base opposite one another in the track flanks. [0044]

Constant Velocity Fixed Joint

	LIst of reference numbers


	11, 41	joint
	12, 42	outer joint part
	13, 43	annular part
	14, 44	attaching part
	15, 45	journal
	16, 46	joint aperture
	17, 47	outer track base
	18, 48	inner guiding face
	--, 49	outer ball track
	22, 52	inner joint part
	23, 53	shaft
	24, 54	inner ball track
	25, 55	outer guiding face
	--, 56	inner ball track
	29, 59	ball cage
	30, --	sliding face
	31, --	sliding face
	32, 62	cage window
	35, 65	ball
	36, 66	pair of tracks
	--, 67	pair of tracks

Constant Velocity Fixed Joint

Claims

1. A constant velocity fixed joint (11) having the following characteristics:

an outer joint part (12) comprises a first longitudinal axis (L₁₂) and an attaching part (14) and an aperture (16) which are axially opposed relative to one another, as well as outer ball tracks (17);

an inner joint part (22) comprises a second longitudinal axis (L₂₂) and inner ball tracks (24);

the outer ball tracks (17) comprise centre lines (S₁₂) and track base lines which extend at equal distances therefrom, which are curved and extend in planes through the first longitudinal axis (L₁₂);

the inner ball tracks (24) comprise centre lines (S₂₂) and track base lines which extend at equal distances therefrom, which are curved and extend in planes through the second longitudinal axis (L₂₂);

the outer ball tracks (17) and the inner ball tracks (24) form pairs of tracks with one another which each receive a torque transmitting ball (35);

a ball cage (29) is positioned between the outer joint part (12) and the inner joint part (22) and comprises circumferentially distributed cage windows which each receive a torque transmitting ball (35);

the centres of the balls are held by the cage (29) in a central plane (E) when the joint is in an aligned condition and in the angle-bisecting plane (E′) when the joint is in an articulated condition;

when the joint is in an aligned condition, the centre lines (S₁₂, S₂₂) of the pairs of tracks are mirror-symmetrical relative to one another with reference to the central plane (E) and when the joint is articulated, they are mirror-symmetrical relative to one another with reference to the angle-bisecting plane (E′);

the track base lines of the pairs of tracks diverge from one another running from the aperture (16) to the attaching part (14);

the track base lines of the outer ball tracks (17) of the pairs of tracks, at the attaching part end, form a radius r_awhose centre (Z₁) is positioned on the first longitudinal axis (L₁₂) so as to be offset by a first offset OFF₁from the central plane (E₁₂) of the outer joint part towards the attaching part, and said track base lines diverge from a circle with said radius r_aoutwardly towards the aperture end;

the track base lines of the inner ball tracks (24) of the pairs of tracks, at the aperture end, comprise a radius r_iwhose centre (Z₂) is positioned on the second longitudinal axis (L₂₂) so as to be offset by a second offset OFF₂from the central plane (E₂₂) of the inner joint part towards the aperture, and said track base lines diverge from a circle with said radius r_ioutwardly towards the attaching part end.

2. A joint according to claim 1,

characterised in

that the track base lines each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_iand a tangentially adjoining straight line portion (S₂). (FIG. 12)

3. A joint according to claim 1,

characterised in

that the track base lines each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_iand a tangentially adjoining second circular-arch-shaped portion (S₅) with the radius R_ae, R_iewhich is greater than the radius r_a, r_i. (FIG. 7)

4. A joint according to claim 1,

characterised in

that the track base lines each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_I, a circular-arch-shaped portion (S₃) with the radius r_1a, r_1icurved in the opposite direction, and a tangentially adjoining straight line (S₄). (FIG. 8)

5. A joint according to claim 1,

characterised in

that the track base lines each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_i, a tangentially adjoining straight line portion (S₂), a circular-arch-shaped portion (S₃) curved in the direction opposite to that of the portion (S₁) and having the radius r_1a, r_1i, and a tangentially adjoining straight line (S₄). (FIG. 9)

6. A constant velocity fixed joint (11) having the following characteristics:

the track base lines of the pairs of tracks diverge from one another running from the aperture (16) towards the attaching part (14);

the track base lines of the outer ball tracks (17) of the pairs of tracks, continuously, comprise a radius r_awhose centre (Z₃) is positioned beyond the first longitudinal axis (L₁₂) and offset by a first offset OFF₁′ from the central plane (E₁₂) of the outer joint part towards the attaching part;

the track base lines of the inner ball tracks (24) of the pairs of tracks, continuously, comprise a radius r_iwhose centre (Z₄) is positioned beyond the second longitudinal axis (L₂₂) and offset by a second offset OFF₂′ from the central plane (E₂₂) of the inner joint part towards the aperture. (FIG. 10)

7. A constant velocity fixed joint (11) having the following characteristics:

the track base lines of the outer ball tracks (17) of said pairs of tracks, at the attaching part end, comprise a radius r_awhose centre (Z₃) is positioned beyond the first longitudinal axis (L₁₂) and offset by a first offset OFF₁′ from the central plane (E₁₂) of the outer joint part towards the attaching part, and said track base lines diverge from a circle with said radius r_aoutwardly towards the aperture end;

the track base lines of the inner ball tracks (24) of the pairs of tracks comprise a radius r_iwhose centre (Z₄) is positioned beyond the second longitudinal axis (L₂₂) and offset by a second offset OFF₂′ from the central plane (E₂₂) of the inner joint part towards the aperture end, and said track base lines diverge from a circle with said radius r_ioutwardly towards the attaching part end.

8. A joint according to claim 7,

characterised in

that the track base lines each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_iand a tangentially adjoining straight line portion (S₂). (FIG. 11)

9. A joint according to claim 7,

characterised in

that the track base lines each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_iand a circular-arch-shaped portion (S₃) curved in the opposite direction with the radius r_1a, r_1iand a tangentially adjoining straight line (S₄). (FIG. 8)

10. A joint according to claim 7,

characterised in

11. A constant velocity fixed joint (41) having the following characteristics:

an outer joint part (42) comprises a first longitudinal axis (L₄₂) and an attaching part (44) and an aperture (46) which are axially opposed relative to one another, as well as outer ball tracks (47, 49);

an inner joint part (52) comprises a second longitudinal axis (L₅₂) and inner ball tracks (54, 56);

the outer ball tracks (47, 49) comprise centre lines (S₄₂) and track base lines which extend at equal distances therefrom, which are curved and extend in planes through the first longitudinal axis (L₄₂);

the inner ball tracks (54, 56) comprise centre lines (S₅₂) and track base lines which extend at equal distances therefrom, which are curved and extend in planes through the second longitudinal axis (L₅₂);

the outer ball tracks (47, 49) and the inner ball tracks (54, 56) form pairs of tracks with one another which each receive a torque transmitting ball (65);

a ball cage (59) is positioned between the outer joint part (42) and the inner joint part (52) and comprises circumferentially distributed cage windows which each receive a torque transmitting ball (65);

the centres of the balls (65) are held by the cage (59) in a central plane (E) when the joint is in an aligned condition and in the angle-bisecting plane (E′) when the joint is in an articulated condition;

when the joint is in an aligned condition, the centre lines of the pairs of tracks are mirror-symmetrical relative to one another with reference to the central plane (E) and when the joint is articulated, they are mirror-symmetrical relative to one another with reference to the angle-bisecting plane (E′);

the track base lines of the pairs of tracks move away from one another in one direction;

the track base lines of one part of the pairs of tracks (49, 56) diverge from one another running from the attaching part (44) to the aperture (46);

the track base lines of another part of the pairs of tracks (47, 54) diverge from one another running from the aperture (46) to the attaching part (44);

the track base lines of the outer ball tracks (17) of said latter pairs of tracks, at the attaching part end, comprise a radius r_awhose centre (Z₁) is positioned on the first longitudinal axis (L₄₂) and offset by a first offset OFF₁′ from the central plane (E₄₂) of the outer joint part towards the attaching part, and said track base lines diverge from a circle with said radius r_aoutwardly towards the aperture end;

the track base lines of the inner ball tracks (54) of said latter pairs of tracks,at the aperture end, comprise a radius r_iwhose centre (Z₂) is positioned on the second longitudinal axis (L₅₂) and offset by a second offset OFF₂′ from the central plane (E₅₂) of the inner joint part towards the aperture, and said track base lines diverge from a circle with said radius r_ioutwardly towards the attaching part end.

12. A joint according to claim 11,

characterised in

that the track base lines of the latter pairs of tracks (47, 54) each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_iand a tangentially adjoining straight line portion (S₂). (FIG. 12)

13. A joint according to claim 11,

characterised in

that the track base lines of the latter pairs of tracks (47, 54) each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_iand a tangentially adjoining second circular-arch-shaped portion (S₅) with the radius R_ae, R_iewhich is greater than the radius r_a, r_i. (FIG. 7)

14. A joint according to claim 11,

characterised in

that the track base lines of the latter pairs of tracks (47, 54) each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_iand a circular-arch-shaped portion (S₃) curved in the opposite direction and having the radius r_1a, r_1iand a tangentially adjoining straight line (S₄). (FIG. 8)

15. A joint according to claim 11,

characterised in

that the track base lines of the latter pairs of tracks (47, 54) each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_i, a tangentially adjoining straight line portion (S₂), a circular-arch-shaped portion (S₃) curved in the direction opposite to that of the portion (S₁) and having the radius r_1a, r_1i, and a tangentially adjoining straight line (S₄). (FIG. 9)

16. A constant velocity fixed joint (41) having the following characteristics:

an outer joint part (42) comprises a first longitudinal axis (L₄₂) and an attaching part (44) and an aperture (46) which are axially opposed relative to one another, as well as outer ball tracks (47);

an inner joint part (52) comprises a second longitudinal axis (L₅₂) and inner ball tracks (54);

the outer ball tracks (47) comprise centre lines (S₄₂) and track base lines which extend at equal distances therefrom, which are curved and extend in planes through the first longitudinal axis (L₄₂);

the inner ball tracks (54) comprise centre lines (S₅₂) and track base lines which extend at equal distances therefrom, which are curved and extend in planes through the second longitudinal axis (L₅₂);

the outer ball tracks (47) and the inner ball tracks (54) form pairs of tracks with one another which each receive a torque transmitting ball (65);

the track base lines of the pairs of tracks diverge from one another running in one direction;

the track base lines of the outer ball tracks (47) of said latter pairs of tracks, continuously, comprise a radius r_awhose centre (Z₃) is positioned beyond the first longitudinal axis (L₄₂) and offset by a first offset OFF₁′ from the central plane (E₄₂) of the outer joint part towards the attaching part;

the track base lines of the inner ball tracks (54) of said latter pairs of tracks, continuously, comprise a radius r_iwhose centre (Z₄) is positioned beyond the second longitudinal axis (L₅₂) and offset by a second offset OFF₂′ from the central plane (E₅₂) of the inner joint part towards the aperture. (FIG. 10)

17. A constant velocity fixed joint (41) having the following characteristics:

the ball cage (59) is positioned between the outer joint part (42) and the inner joint part (52) and comprises circumferentially distributed cage windows which each receive a torque transmitting ball (65);

the track base lines of the outer ball tracks (47) of said latter pairs of tracks, at the attaching part end, comprise a radius r_awhose centre (Z₃) is positioned beyond the first longitudinal axis (L₄₂) and offset by a first offset OFF₁′ from the central plane (E₄₂) of the outer joint part towards the attaching part, and said track base lines diverge from a circle with said radius r_aoutwardly towards the aperture end;

the track base lines of the inner ball tracks (54) of said latter pairs of tracks comprise a radius r_iwhose centre (Z₄) is positioned beyond the second longitudinal axis (L₅₂) and offset by a second offset OFF₂′ from the central plane (E₅₂) of the inner joint part towards the aperture, and said track base lines diverge from a circle with said radius r_itowards the attaching part end.

18. A joint according to claim 17,

characterised in

that the track base lines of the latter pairs of tracks each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_iand a tangentially adjoining straight line portion (S₂). (FIG. 11)

19. A joint according to claim 17,

characterised in

that the track base lines of the latter pairs of tracks each consist of a circular-arch-shaped portion (S₁) with the radius r_a,r_i, a circular-arch-shaped portion (S₃) with the radius r_1a, r_1icurved in the direction opposite thereto, and a tangentially adjoining straight line (S₄). (FIG. 8).

20. A joint according to claim 17,

characterised in

that the track base lines of the latter pairs of tracks each consist of a circular-arch-shaped portion (S₁) with the radius r_a, r_i, a tangentially adjoining straight line portion (S₂), a circular-arch-shaped portion (S₃) curved in the direction opposite to that of the portion (S₁) and having the radius r_1a, r_1i, and a tangentially adjoining straight line (S₄). (FIG. 9)