DE102020211049A1 - tripod joint - Google Patents

Abstract

A tripod joint comprises a tripod star (10) with radially projecting pins (12), rolling elements (13) which are rotatably mounted on the pins (12) by means of needles (14), a support ring (16) for the needles (14), which an annular space (15) accommodating the needles (14) is delimited radially on the outside in the direction of the longitudinal axis of the pin (Z) in order to limit the outward migration of the needles (14), a protruding needle head (14a) of the needles (14) having a stop surface ( 16a) of the support ring (16) comes into contact, and a snap ring (17) which is arranged in a groove (12b) and forms an abutment in the longitudinal direction (Z) of the pin (12) outwards for the support ring (16). The stop surface (16a) of the support ring (16) for the needle heads (14a) of the needles (14) arranged in the annular space (15) has a contour that slopes down axially in the longitudinal direction (Z) of the pin (12, 12') and extends in Tapered towards the needle heads (14a) of the needles (14).

Description

The invention relates to a tripod joint comprising a tripod star with radially projecting journals, rolling elements which are mounted on the journals of the tripod star so as to be rotatable about a longitudinal axis of the respective journal projecting radially from the tripod star, needles which, in an annular space between an outer circumference of the journal and the inner circumference of the rolling element, are arranged in the circumferential direction around the journal in order to support the rolling element on the journal, and each have a protrusion as a needle head at their front end, a support ring, the needles of an annular space which extends the annular space in the direction of the The longitudinal axis of the spigot is limited radially on the outside to restrict outward migration of the needles, with the needle heads of the needles coming into contact with a stop surface of the support ring, and a snap ring which is arranged in a groove and an abutment in the longitudinal direction of the spigot to the outside for the support ring forms.

Such a tripod joint is out JP 2000220655 A as well as off DE 10 2020 102 218 A1 famous. With these tripod joints, however, securing the needles axially is problematic. On the one hand, in the case of high axial forces on the needles, ie in the longitudinal direction of the pin, the fuse can be overcome. On the other hand, the support ring is exposed to increased loads, particularly in vehicles that recuperate when braking for the purpose of energy recovery.

A correspondingly more massive design of the support ring and snap ring would require a greater height of the annular space accommodating the needles and needles with a larger diameter, which in turn would result in larger overall dimensions of the joint and a higher component weight.

The torque to be transmitted by a tripod joint results in a force between a raceway on the outer joint part and the rolling element 13 rotatably mounted on the inner joint part or tripod star. This force is transmitted via the needles 14 to the pin 12 of the tripod star. In addition, when an angular offset is compensated for between the outer joint part and the inner joint part, there is an axial displacement between the rolling element, which is centered in the raceway of the outer joint part via its outer contact surface, to the needle running surface of the tripod star. This creates frictional forces FNR and F _NZ on the needles (cf. 1 ). If the needles 14 are taken along by the rolling element 13 in the direction of the support ring 16, the needle travel can be limited by the axial needle safety device from the support ring 16 and the snap ring 17. Here, supporting forces F _NS act between the support ring and the heads of the needles. In addition, the axial securing serves to prevent the loss of needles and rolling elements, in particular before assembly in the outer joint part. In general, there is a spatial characteristic of the load over several needles, ie supporting forces occur on several needles at the same time. In order to make the train of thought easier to understand, however, the explanations below are reduced to a sectional level.

Relatively small diameters d _N of the needles are advantageous for a compact and cost-effective construction of a tripod joint. This in turn affects the space available for the support ring and the snap ring. How out 1 As can be seen, the rolling element 13 is pushed over the support ring 16. As a result, the maximum outer diameter d _Ba of the support ring 16 is limited. When the snap ring 17 is installed, it sits on the diameter d _Z of the needle running surface of the pin 12 of the tripod star. The snap ring 17 must be guided under the support ring inner diameter d _Bi through the gap s to the needle running surface in order to get into the groove of the pin on the tripod star. This must be taken into account when configuring the height of the annular space 15 accommodating the needles 14 .

If the support ring is to be produced by stamping and bending sheet material with an approximately constant sheet thickness, the maximum sheet thickness tmax results from the following formula: tmax = dN-dS

Electrified drives in particular place greater stress on the axial safety mechanism of the needles, since recuperation takes place in electrified drives. For the tripod joint, this leads to stress in traction and overrun operation. During operation, the support ring is rotated around the axis of rotation of the tripod star. As a result, the additional load is distributed over the support ring, which must be strengthened. The needle running surfaces, on the other hand, are oriented to the direction of the load, so that an additional load from increased overrun operation does not lead to any additional stress on the needle running surfaces of the tripod star, which are in the power flow during traction operation. However, this does not apply to the support ring. This is exposed to an increased load. The axial locking of the needles must therefore be designed in such a way that the snap ring remains securely in the groove.

Depending on the position of the contact points between the support ring and the needle heads on the one hand and the support ring and the snap ring on the other the support ring 16 is also subjected to bending. how 1 shows, the contact surface of the support ring, which comes into contact with the protruding needle head, is designed perpendicular to the axis of rotation of the support ring. This axis of rotation corresponds to the longitudinal axis of the associated pin. 2 shows the consequence of the centering of the snap ring 17 in the groove in combination with the contact of the needle head on the contact surface. Initially, there is no balance of forces, which is why the support ring 16 subsequently moves until the balance of forces is established by the displacement of the contacts between the support ring and the snap ring and the needle head and the additional contact of the support ring on the opposite side is. The state of equilibrium means a bending load for the support ring, since the lines of action k ₁ and k ₂ are at a distance from one another. If the support ring lies against the snap ring via a chamfer, as shown in 2a is shown, there is also a bending stress from a radial force component k ₃ , which is supported on the opposite side in the area of the needle running surface. Bending loads usually lead to higher stresses in components than e.g. B. pure pressure or tensile loads. With each rotation of the tripod joint, the rolling element is displaced relative to the journal of the tripod star and thus the possibility of the needle resting on the support ring 16. This situation represents an increasing bending load on the support ring.

The object of the invention is to remedy this situation. In particular, the invention aims to provide a compact tripod joint which withstands increased collective loads without sacrificing service life.

This object is achieved by a tripod joint according to claim 1. The tripod joint according to the invention comprises a tripod star with radially projecting journals, rolling elements which are mounted on the journals of the tripod star so as to be rotatable about a longitudinal axis of the respective journal projecting radially from the tripod star, needles which are located in an annular space between an outer circumference of the journal and the inner circumference of the rolling element is formed, are arranged in the circumferential direction around the journal in order to support the rolling element on the journal, and each have a protrusion as a needle head at their front end, a support ring, the needles of an annular space, which radially expands the annular space in the direction of the longitudinal axis of the journal restricted on the outside to limit outward migration of the needles with the needle heads of the needles coming into contact with an abutment surface of the support ring, and a snap ring which is arranged in a groove and forms an abutment in the longitudinal direction outwards of the spigot for the support ring. It is characterized in that the stop surface of the support ring for the needle heads of the needles arranged in the annular space has a contour that slopes down axially in the longitudinal direction (Z) of the pin (12, 12') and tapers in the direction of the needle heads of the needles.

In this way, a lower bending load on the support ring is achieved without changing the outer dimensions, since the contact with the needle heads moves closer in the direction of the longitudinal axis of the pin and thus in the direction of the contact of the support ring with the snap ring.

According to a particular embodiment of the invention, the sloping contour of the abutment surface is selected from a conical contour and an inwardly curved contour. The former enables simple production, the latter reduces the Hertzian pressure on contact by clinging to the protruding needle head.

According to a further special embodiment of the invention, the support ring has a contact surface opposite the stop surface for resting against the snap ring, which has a contour that slopes down in the same direction as the stop surface. This favors a more stable support of the needles, since the snap ring is pushed more strongly into the groove under load. The contouring itself, not the direction of the drop, can optionally be selected differently for the stop surface and contact surface.

Preferably, when viewed in a longitudinal sectional plane of the spigot, a line connecting the contact of a needle head with the abutment surface and the contact between the snap ring and the contact surface on the support ring is angled to the longitudinal axis of the spigot.

In the present case, two lines or planes which enclose a smallest intersection angle greater than 0° and smaller than 90° with one another are understood to be angled towards one another

Ideally, the connecting line runs perpendicularly to the stop surface and/or contact surface, with small deviations of the order of magnitude of up to approximately +/-2° being able to be tolerated. This also promotes more stable support for the needles, since the snap ring is pushed more strongly into the groove under load, and at the same time there is less bending stress on the support ring.

It has also been shown that the angle of inclination of the stop surface to the longitudinal axis of the pin is 60° to 80° and more preferably 64° to 80° and even more preferably 69° to 75° should be considered, since the bulging of the needle heads is generally roughly tolerated. Narrow tolerances would significantly increase the manufacturing costs for the needles. In the case of a curved surface, said angle of inclination is to be understood as being related to the tangent at the point of contact.

Similarly, the angle of inclination of the contact surface to the longitudinal axis of the pin should be 55° to 80° and more preferably 59° to 80° and even more preferably 69° to 75° in order to achieve particularly favorable contact conditions on the snap ring.

The support ring is preferably designed as a shaped sheet metal part with a substantially constant wall thickness, which means that it can be produced simply and inexpensively by stamping and/or bending.

According to another special embodiment of the invention, the line of action of force of the contact between the needle head and stop surface and the line of action of force between snap ring and contact surface coincide or both deviate from each other by a maximum of 2°, with the line of action of force having an angle in the range of 10° with the longitudinal axis of the pin include up to 25°. This measure can also be used to reduce bending stresses on the support ring to the greatest possible extent, without the annular space for the needles having to be of a greater height for this purpose.

In a further embodiment variant, the lines of action of force run through the center point of the ring cross-section of the snap ring.

It has proven to be particularly favorable if the lines of action of force meet the outer side wall of the groove in a middle third of the height of the groove.

Furthermore, the stop surface of the support ring can merge into a cylindrical wall section of the same, the outside diameter of which is smaller than the maximum inside diameter of the annular space. The support ring can thus extend into the annular space between the rolling element and the journal. On the other hand, collisions between the rolling element and the support ring are avoided during operation.

Furthermore, an angled wall section can adjoin the cylindrical wall section, the maximum external diameter of which is greater than the maximum internal diameter of the annular space. This prevents the rolling element from slipping off the tripod star during assembly.

According to another particular embodiment, the abutment surface and the contact surface are parallel to one another when viewed in a longitudinal section plane of the pin. This combines low bending stress on the support ring with stable support for the axial securing of the needles and simple manufacture.

All dimensions and geometric relationships in the present disclosure relate to a design center position of all components of the joint. In particular, this is here in the unbent state, with the rolling elements, needles, support and snap rings being arranged concentrically around the respective longitudinal axis of the associated pin.

• 1 eine schematische Darstellung einer herkömmlichen Axialsicherung für die Nadeln eines Tripodegelenks,
• 2 das Einstellen eines Kräftegleichgewichts an einem herkömmlichen Tripodegelenk,
• 2A das Einstellen eines Kräftegleichgewichts an einem weiteren herkömmlichen Tripodegelenk,
• 3 eine Schnittansicht eines Tripodegelenks nach einem Ausführungsbeispiel der Erfindung quer zur Drehachse des Tripodegelenks,
• 4 eine Schnittansicht quer zur Längsachse eines Zapfens des Tripodegelenks,
• 5 eine Detailansicht der Axialsicherung der Nadeln nach der Erfindung,
• 6 verschiedene Varianten für den Querschnittsverlauf des Stützrings,
• 7 eine Variante eines Stützrings mit einwärts gewölbter Anlagefläche für die Nadeln, und in
• 8 ein zweites Ausführungsbeispiel eines Tripodegelenk nach der Erfindung.

The invention is explained in more detail below with reference to exemplary embodiments illustrated in the drawing. The drawing shows in:

• 1 a schematic representation of a conventional axial lock for the needles of a tripod joint,
• 2 the setting of a balance of forces on a conventional tripod joint,
• 2A the setting of a force balance on another conventional tripod joint,
• 3 a sectional view of a tripod joint according to an embodiment of the invention transverse to the axis of rotation of the tripod joint,
• 4 a sectional view transverse to the longitudinal axis of a pin of the tripod joint,
• 5 a detailed view of the axial locking of the needles according to the invention,
• 6 different variants for the cross-section of the support ring,
• 7 a variant of a support ring with an inwardly curved contact surface for the needles, and in
• 8th a second embodiment of a tripod joint according to the invention.

the 3 until 5 show a first embodiment of a tripod joint 1 according to the invention.

The tripod joint 1 enables torque and speed to be transmitted between two shafts while at the same time equalizing the angular and length offset between the shafts.

Joints of this type come as constant velocity plunging joints z. B. in side shafts of motor vehicles, especially passenger vehicles, preferably on the transmission side for one sentence. Relative movements between a wheel hub and a transmission output result in an angular and length offset of the connection points, which is compensated for by the tripod joint while ensuring torque and speed transmission.

The tripod joint 1 of the first exemplary embodiment comprises an inner joint part in the form of a tripod star 10 with a shaft section 11 and pins 12 protruding radially from the shaft section 11. The pins 12 are arranged at the same distance from one another in the circumferential direction. Their longitudinal axes Z run essentially radially to the axis of rotation A of the inner joint part or tripod star 10. Preferably, as in the exemplary embodiment shown, these lie in a common plane.

Furthermore, the tripod joint 1 on the tripod star 10 comprises three rolling elements 13 which are each mounted on one of the pins 12 so as to be rotatable about the longitudinal axis Z of the same. The rolling elements 13 preferably form a profiled, rotationally symmetrical outer peripheral surface 13a. The number of rolling elements 13 can also be smaller or larger than shown.

The tripod joint 1 also includes an outer joint part 20 with an engagement section for the rolling elements 13. The engagement section is designed, for example, like a sleeve and can have a constant cross-sectional profile over its axial length. In particular, the engagement section has, on its inner circumference, pairs of raceways running parallel to the axis of rotation B of the outer joint part 20, with raceways 21a and 21b lying opposite one another in the circumferential direction. These raceways 21a and 21b are in engagement with the outer peripheral surfaces 13a of the rolling elements 13, with one of the raceways 21a being load-bearing and the opposite raceway 21b being essentially unloaded, depending on the direction of rotation and the operating situation.

The rolling elements 13 are mounted on the journals 12 with the interposition of a roller bearing, which in the present case is designed as a needle bearing. For this purpose, the tripod joint 1 has needles 14 which are arranged in the circumferential direction around the pin 12 in an annular space 15 which lies between an outer periphery of the pin 12 and the inner periphery of the rolling element 13 . The needles 14 each have a protrusion as a needle head 14a at their front end.

In the illustrated first exemplary embodiment, the annular space 15 is delimited by an inner peripheral surface 13b of the rolling element 13 and an outer peripheral surface 12a of the pin 12, which at the same time form the running surfaces for the needles 14.

To secure the needles 14 axially, i.e. to limit their outward migration in the longitudinal direction Z of the pin 12 , the tripod joint 1 has a securing device which includes a support ring 16 and a snap ring 17 . Both are designed as separate components.

While the support ring 16 sits loosely on the pin 12, ie has some play in relation to the pin 12 and can be tilted slightly, for example, relative to a normal plane to the longitudinal axis Z, the snap ring 17 is fixed in a groove 12b of the pin 12, which is concentric with the Longitudinal axis Z of the pin 12 is inserted. The snap ring 17 forms an abutment for the support ring 16 in the longitudinal direction Z of the journal 1, i.e. radially outward in relation to the tripod star 10.

The support ring 16 for the needles 14 within the annular space 15 has a stop surface 16a, which is oriented towards the curved heads 14a of the needles 14, and a contact surface 16b opposite thereto for support against the snap ring 17.

The stop surface 16a of the support ring 16 for the heads 14a of the needles 14 arranged in the annular space 15 has an axially sloping contour in the longitudinal direction Z of the pin 12, which tapers in the direction of the heads 14a of the needles 14. The stop surface 16a accordingly deviates from a plane normal to the longitudinal axis Z. In the exemplary embodiment shown, the stop surface 16a has a conical contour, but it can also have a different course, sloping down over an axial path in the direction of the longitudinal axis, for example inwardly curved, in order to reduce the Hertzian pressure with the protruding needle head 14a.

Accordingly, in the illustrated first exemplary embodiment, the stop surface 16a of the support ring 16 is in the longitudinal section plane of the pin 12, as shown in FIG 5 shown, angled to the longitudinal axis Z of the pin 12 by an angle β. In comparison to a stop surface perpendicular to the longitudinal axis Z, the contact K _N moves closer to the needle heads 14a in the direction of the longitudinal axis Z and thus closer in the direction of the contact K _S between the snap ring 17 and the support ring 16. This reduces any bending loads on the support ring 16 reduced.

The contact surface 16b opposite the stop surface 16a is also to the longitudinal Axis Z of the pin 12 angled, preferably in substantially the same way as the stop surface 16a. As a result, under load, the snap ring 17 is increasingly pushed into the groove 12b of the journal 12, so that high forces can be absorbed in the axial direction of the needles 14 and thus radially with respect to the tripod star 10.

how 5 can be seen, when viewed in the longitudinal section plane of the pin 12, a connecting line I between the contact K _N of a needle head 14a with the stop surface 16a and the contact Ks between the snap ring 17 and the contact surface 16b on the support ring 16 to the longitudinal axis Z of the pin 12 um employed an angle of inclination α.

The angle of inclination β _N of the stop surface 16a for the needles 14 to the longitudinal axis Z of the pin 12 is 60° to 80°, more preferably 64° to 80° and even more preferably 69° to 75°.

The angle of inclination β _S of the contact surface 16b for the snap ring 17 to the longitudinal axis Z of the pin 12 is 55° to 80°, more preferably 59° to 80° and even more preferably 69° to 75°.

The angles of inclination α _N and α _S are preferably the same or at least approximately the same. This has advantages in terms of manufacturing technology, since the support ring 16 can then be produced as a simple shaped sheet metal part with a constant wall thickness. The stop surface 16a and the contact surface 16b are ideally parallel to one another when viewed in a longitudinal section plane of the pin 12 . However, this is not mandatory. Slightly different angles of inclination α _N and α _S can possibly result in an even better adaptation to the surface contours of the curved needle heads 14a and the snap ring 17 .

In the exemplary embodiment shown, the connecting line I runs essentially perpendicularly to the stop surface 16a and preferably also to the contact surface 16b, with deviations from the perpendicular of approximately +/-2° being able to be tolerated.

With regard to a low bending load, the line of action of force k _N of the contact K _N between the needle head 14a and the stop surface 16a coincides with the line of action of force k _S between the snap ring 17 and the contact surface 16b. Deviations of a maximum of 2° can be tolerated. At the same time, the force action lines k _N and ks enclose an angle α _N/S in the range of 10° to 25° with the longitudinal axis Z of the pin 12 .

In a modification of the exemplary embodiment, an angular deviation between the lines of action of force k _N and k _S , which goes beyond manufacturing tolerances, is provided. This deviation is preferably limited to a maximum of +/- 10° and possibly only +/- 5°.

Furthermore, the lines of action of force k _N and ks can run through the center point M of the ring cross section of the snap ring 17 . In the present case, this is shown with a circular ring cross section. However, other cross-sectional shapes are also possible.

In addition, the lines of action k _N and ks can be designed in relation to the position and dimensions of the groove 12b such that they meet the outside groove side wall 12c in a middle third of the groove height H of the groove 12b.

The stop surface 16a merges into a cylindrical wall section 16c, the outer diameter of which is smaller than the maximum inner diameter of the annular space 15. The support ring 16 can thus be pushed partially into the annular space 15 between the rolling element 13 and the pin 12 . However, collisions with the rolling element 13 during operation are avoided.

The cylindrical wall section 16c is in turn adjoined by an angled wall section 16d, the maximum external diameter of which is larger than the maximum internal diameter of the annular space 15, which ensures that it cannot be lost during assembly.

6 illustrates different variants (a) to (c) for contours of the cross section of the support ring 16.

In the first variant denoted by (a), the stop surface 16a and the contact surface 16b run parallel to one another within the framework of normal manufacturing tolerances. The entire support ring 16 has a constant wall thickness. A chamfer does not have to be specially produced for the contact surface 16b. The stop surface 16a and the contact surface 16b are each conical in the contact area with the needle heads 14a and with the snap ring 17, the angle of attack to the normal plane of the longitudinal direction Z being 21°. This corresponds to an angle of inclination β _N of the stop surface 16a and an angle of inclination β _S of the contact surface 16b of 69° in each case.

In the second variant denoted by (b), the stop surface 16a and the contact surface 16b again run parallel to one another within the framework of usual manufacturing tolerances. In contrast to according to the first variant 6 (a) the angle of attack of the stop surface 16a and the contact surface 16b in the contact area with the needle heads 14a and with the snap ring 17 to the normal plane of the longitudinal direction Z is only 15°. This corresponds to an angle of inclination β _N of the stop surface 16a and an angle of inclination β s of the contact surface 16b of 75° in each case.

In the third variant denoted by (c), a curved contour R is provided in the contact area of stop surface 16a and contact surface 16b instead of a cone contour. At the stop surface 16a, the curvature is concave, ie curved inwards. On the opposite side, ie on the contact surface 16b, there is a convex contour. As a result, as in 7 shown, a good clinging of the stop surface 16a to the protruding needle heads 14a is achieved. This reduces the Hertzian pressure and reduces the risk of the support ring 16 jamming.

In 6(c) the course of the two curved contours is essentially parallel, with which the support ring 16 can advantageously be produced from a sheet metal blank with a constant wall thickness.

However, the contact surface 16b can also be contoured in a more complex manner, for example as in variants (a) and (b) of FIG 6 be executed.

7 shows as a further alternative the formation of the contact surface 16b by a chamfer.

Further illustrated 7 For example, the possibility of an angular deviation of the lines of action of force k _N and ks, be it within the scope of manufacturing tolerances or a desired deviation of up to a maximum of +/- 10°.

The axial securing for the needles 14 was described here using an exemplary embodiment in which the needle running surfaces are formed directly on the pin 12 and on the rolling element 13 . However, this can also be used in other types of tripod joints in which a multi-part rolling element 13' is used, as is the case in the modification according to FIG 8th is shown. The rolling element 13' here comprises an outer ring 18' and an inner ring 19' which can be rotated in relation to one another via needles 14'.

An inner peripheral surface 19a' of the inner ring 19' can be of essentially cylindrical design and engage with a convex outer peripheral surface 12a' of the pin 12', so that when the tripod joint 1' bends, the inner ring 19' moves relative to the longitudinal axis Z of the associated pin 12 ' is tiltable. Profiling both the raceways 21a' and 21b' on the joint outer part 20' and the outer peripheral surfaces 18a' of the outer rings 18 of the rolling elements 13' causes the rolling elements 13' to rotate when the joint 1 rotates with the component axes A and B bending towards one another. are moved back and forth axially parallel to the axis of rotation B of the outer joint part 20'. The degree of pivoting freedom required for this is provided by the pins 12' and the inner rings 19' of the rolling elements 13'.

In this type of joint, the relevant annular space 15' is formed between the inner ring 19' and the outer ring 18' of the rolling element 13'. Accordingly, the groove for the snap ring 17 is cut into the outer peripheral surface 19b' of the inner ring 19'. The support ring 16 of the type explained above extends into this annular space 15 ′, the snap ring 17 serving as an axial abutment in the longitudinal direction Z of the pin 12 to the outside.

The invention was explained in more detail above on the basis of various exemplary embodiments and further modifications. These serve to demonstrate the feasibility of the invention. Individual technical features that have been explained above in the context of other individual features can also be implemented independently of these and in combination with other individual features, even if this is not expressly described, as long as this is technically possible. The invention is therefore expressly not limited to the embodiment variants specifically described, but rather includes all configurations defined by the patent claims.

Reference List

1, 1'

tripod joint

10, 10'

tripod star

11, 11'

wave section

12, 12'

cones

12a

Outer peripheral surface of the pin

12a'

convex outer peripheral surface of the pin 12'

12b

groove

12c

outside groove side wall

13, 13'

rolling element

13a

outer peripheral surface

14, 14'

needle

14a

head of the needle

15, 15'

annulus

16

support ring

16b

contact surface

16a

stop surface

17

snap ring

16c

cylindrical wall section

16d

angled wall cut

18'

outer ring

18a'

Outer peripheral surface of the outer ring 18

19'

inner ring

19a'

Inner peripheral surface of the inner ring 19'

19b'

Outer peripheral surface of the inner ring 19'

20, 20'

joint outer part

21a, 21a'

career

21b, 21b'

career

dN

diameter of the needles

dBa

maximum outer diameter of the support ring

dBi

Support ring inner width in the area of the snap ring

dS

snap ring diameter

dz

Diameter of the needle running surface of the journal 12

kN

Line of action of force of contact K _N

ks

Line of action of force of the contact K _S

I

Connecting line between the contact K _N and the contact Ks

s

gap

t

sheet thickness

A

Axis of rotation of the tripod star

B

Axis of rotation of the joint outer part

H

Groove height of the groove 12b

FNR

Friction force needle/roller element

FNZ

Friction force needle/pin

FNS

support force on the snap ring

KN

Contact between needle head 14a and support ring 16

KS

Contact between snap ring 17 and support ring 16

M

Center of ring cross-section of snap ring 17

R

curvature

Z

longitudinal axis

a

Angle of the line of action of the force to the longitudinal axis Z

β

tilt angle

βN

Angle of inclination of the conical stop surface 16a to the longitudinal axis Z of the pin 12

βs

Angle of inclination of the contact surface 16b to the longitudinal axis Z of the pin 12

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• JP2000220655A [0002]
• DE 102020102218 A1 [0002]

Claims (13)

Tripod joint (1, 1'), comprising a tripod star (10, 10') with radially projecting pins (12, 12'), rolling elements (13, 13') which are mounted on the pins (12, 12') of the tripod star (10 , 10') are rotatably mounted about a longitudinal axis (Z) of the respective journal (12, 12') projecting radially from the tripod star, needles (14, 14') which in an annular space (15, 15') between an outer circumference of the journal (12, 12') and the inner circumference of the rolling element (13, 13') are arranged circumferentially around the trunnion (12, 12') to fasten the rolling element (13, 13') on the trunnion (12, 12'). and each having a protrusion as a needle head at their front end, a support ring (16) for the needles (14, 14') of an annular space (15, 15') which extends the annular space (15, 15') in the direction of the longitudinal axis of the pin (Z) is limited radially on the outside in order to restrict outward migration of the needles (14, 14'), the needle heads (14a) of the needles (14, 14') coming into contact with a stop surface (16a) of the support ring (16). gene, and a snap ring (17) which is arranged in a groove (12b) and forms an abutment in the longitudinal direction (Z) of the pin (12, 12') to the outside for the support ring (16), characterized in that the stop surface (16a) of the support ring (16) for the needle heads (14a) of the needles (14, 14') arranged in the annular space (15, 15') has a contour that slopes down axially in the longitudinal direction (Z) of the pin (12, 12'), which tapers towards the needle heads (14a) of the needles (14, 14'). tripod joint (1, 1'). claim 1 , characterized in that the sloping contour of the stop surface (16a) is selected from a conical contour and an inwardly curved contour. tripod joint (1, 1'). claim 1 or 2 , characterized in that the support ring (16) has a contact surface (16b) opposite the stop surface (16a) for abutment against the snap ring (17), which has a contour sloping in the same direction as the stop surface (16a), wherein when viewed in a longitudinal section plane of the pin (12, 12') a connecting line (I) between the contact (K _N ) of a needle head (14a) with the stop surface (16a) and the contact ( _KS ) between the snap ring (17) and the contact surface ( 16b) on the support ring (16) is angled towards the longitudinal axis of the pin (12, 12'). tripod joint (1, 1'). claim 3 , characterized in that the connecting line (I) to the stop surface (16a) runs perpendicularly +/- 2° and/or the connecting line (I) to the contact surface (16b) runs perpendicularly +/- 2°. Tripod joint (1, 1 ') according to one of Claims 1 until 4 , characterized in that the angle of inclination (β _N ) of the stop surface (16a) to the longitudinal axis (Z) of the pin (12, 12') is 60° to 80°. Tripod joint (1, 1 ') according to one of Claims 1 until 5 , characterized in that the angle of inclination (βs) of the contact surface (16b) to the longitudinal axis (Z) of the pin (12, 12') is 55° to 80°. Tripod joint (1, 1 ') according to one of Claims 1 until 6 , characterized in that the support ring (16) is a shaped sheet metal part with a substantially constant wall thickness. Tripod joint (1, 1 ') according to one of Claims 1 until 7 , characterized in that the line of action (k _N ) of the contact (K _N ) between the needle head (14a) and the stop surface (16a) coincides with the line of action of the force (ks) of the contact (Ks) between the snap ring (17) and the contact surface (16b), or both deviate from each other by a maximum of 2°, the lines of action of the force enclosing an angle (α _N , α _S ) in the range from 10° to 25° with the longitudinal axis (Z) of the pin (12, 12'). tripod joint (1, 1'). claim 8 , characterized in that the lines of action of force (k _N , k _S ) run through the center point (M) of the annular cross-section of the snap ring (17). tripod joint (1, 1'). claim 7 or 8th , characterized in that the lines of action of force (k _N , k _S ) meet the outside groove side wall (12c) in a middle third of the groove height (H) of the groove (12b). Tripod joint (1, 1 ') according to one of Claims 1 until 10 , characterized in that the stop surface (16a) merges into a cylindrical wall section (16c) whose outside diameter is smaller than the maximum inside diameter of the annular space (15, 15'). tripod joint (1, 1'). claim 11 , characterized in that the cylindrical wall section (16c) is followed by an angled wall section (16d) whose maximum outside diameter is greater than the maximum inside diameter of the annular space (15, 15'). Tripod joint (1, 1 ') according to one of Claims 1 until 12 , characterized in that the stop surface (16a) and the contact surface (16b) for the snap ring (17) when viewed are parallel to one another in a longitudinal section plane of the pin (12, 12').

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