Tripod type joint and automobile

Abstract

The tripod joint (1) comprises an outer joint part (2) and an inner joint part (7). The outer joint part (2) has a first longitudinal axis (3) and a cavity (4) extending parallel to the first longitudinal axis (3) and having an open end (5), with three recesses (6) extending parallel to the first longitudinal axis (3). The inner joint part (7) has a second longitudinal axis (8) and at least one central body (9). The central body (9) is formed with three journals (10). Each journal (10) has a roller body (13) disposed thereon, and the roller body (13) has at least one outer ring (14) and an inner ring (16) rotatable relative to the outer ring (14) around a common rotation axis (15). At least when the longitudinal axes (3, 8) are coaxially arranged and a torque acting in the circumferential direction (18) is transmitted during the intended operation of the tripod joint (1), the force is transmitted between the journal (10) and the inner ring (16) via two contact points (19, 20), which are arranged at a distance from each other along the radial direction (11) in a cross section (21) of the tripod joint (1) extending transversely to the longitudinal axes (3, 8).

Description

[Technical Field]

[0001] The present invention relates to a tripod joint having an outer joint part and an inner joint part with a central body having three journals formed integrally therewith, each journal having a roller body disposed thereon, and also to a motor vehicle equipped with this type of tripod joint.

[0002] This type of tripod joint typically includes an outer joint part having a first longitudinal axis and a cavity extending parallel to the first longitudinal axis and having open ends, with three recesses formed in the outer joint part and extending parallel to the first longitudinal axis. The tripod joint also includes an inner joint part having a second longitudinal axis and at least one central body on which three journals are formed, each journal having a journal axis extending radially from the second longitudinal axis. Each journal is provided with a roller body, which includes at least one outer ring, an inner ring rotatable relative to the outer ring about a common axis of rotation, and a bearing disposed between the outer and inner rings. Each roller body is movably received in a recess and can move along the first longitudinal axis.

[0003] To assemble the tripod joint, the inner joint part, having the journals and the roller bodies disposed thereon, can be inserted into the cavity of the outer joint part via the open end.

[0004] The central body may itself be the shaft or may be connected to the shaft via splines or the like.

[0005] The inner joint portion can be displaced along the first longitudinal axis relative to the outer joint portion and can be bent relative to the outer joint portion through a flexion angle, the flexion angle being a minimum angle between the first longitudinal axis and the second longitudinal axis.

[0006] Tripod joints have been manufactured and sold by the applicant for a long time, for example under the name AAR tripod joint. These tripod joints are used for side shafts of motor vehicles and serve in particular as the drive connection between the differential gear and the drive wheels. On the wheel side, so-called constant velocity ball joints are usually used, and the AAR tripod joint mentioned here is used as a sliding joint next to the differential gear. AAR tripod joints are designed in particular for bending angles of the order of 23-26° (or less).

[0007] In the AARi tripod joint, a subtype of the AAR tripod joint, the inner ring is cylindrical towards the journal and is fixed to the outer ring in the direction along the axis of rotation by a retaining ring.

[0008] The journals contact the inner rings of the respective bearings or roller bodies via so-called sliding surfaces (contact surfaces), which are designed in particular in the shape of a truncated sphere. These sliding surfaces are aligned circumferentially around the second longitudinal axis, so that torques acting around the longitudinal axes of the joint are transmitted via the sliding surfaces of the journals to the roller bodies and vice versa.

[0009] In towing operation of the vehicle, i.e. when the vehicle is driven by the drive unit, the journal contacts one sliding surface of the roller body, in particular the roller body contacts one side of the recess. When the vehicle is in engine braking or coasting mode (both referred to as coasting mode), i.e. when a drive torque is applied from the wheels and the drive unit is still connected (engine braking mode) or disconnected (coasting mode), the journal contacts the other sliding surface of the roller body, in particular the roller body contacts the opposite side of the recess. In engine braking or coasting mode, the direction of the applied torque and the direction of rotation of the joint are opposite to each other, while in towing mode they are in the same direction.

[0010] A tripod joint is known from US Pat. No. 5,623,999, in which the inner ring has a chamfer on the front surface facing the central body of the inner joint part. This chamfer serves to allow the roller body to be mounted on the journal. Due to the reduced contact surface on the inner ring, unacceptably high end loads may occur on the inner ring during the intended operation of the tripod joint, which may result in a shortened service life.

[0011] In the tripod joint known from US Pat. No. 5,649,999, the inner ring has localized ridges that determine its position relative to the journal.

[0012] In either case, when a tripod joint operates as intended, torque acting in the circumferential direction is transmitted between the journal and the inner ring through a single contact point.

[0013] In particular, when the tripod joint operates at a flexion angle, this contact point can move along the axis of rotation and can move along the contour of the inner surface of the inner ring or the contour of the outer surface of the journal.

[0014] If this contact point is located further outward in the radial direction, it will still be far from the edge of the inner peripheral surface of the inner ring that is intended to contact the journal, thereby achieving regular and smooth power transmission.

[0015] However, if this contact point were located further radially inward, it could be at the edge of the inner ring's inner surface intended to contact the journal, due to the shortened profile created by the chamfer. This could result in uneven power transmission and increased end loads. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] U.S. Patent No. 7,654,908 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-286046 Summary of the Invention [Problem to be solved by the invention]

[0017] The object of the present invention is to solve at least some of the problems described in relation to the prior art, and in particular to propose a tripod joint in which the end loads on the inner ring are reduced during the intended operation, which will make the tripod joint more durable and have a longer service life. [Means for solving the problem]

[0018] These problems are solved by a tripod joint according to the features of claim 1. The dependent claims provide further advantageous embodiments. It should be noted that the features individually recited in the dependent claims may be combined with one another in any technically advantageous manner to define further embodiments of the invention. In addition, the features recited in the respective claims are described and explained in more detail in the present specification, thereby describing further preferred embodiments of the invention.

[0019] The object is achieved by the following tripod joint. The tripod joint includes an outer joint part and an inner joint part. The outer joint part has a first longitudinal axis and a cavity extending parallel to the first longitudinal axis and having an open end. The outer joint part is formed with three recesses extending parallel to the first longitudinal axis. The inner joint part has a second longitudinal axis. The inner joint part has at least one central body formed with three journals having journal axes extending radially outward from the second longitudinal axis. A roller body is disposed on each journal, and the roller body has at least an outer ring, an inner ring rotatable relative to the outer ring about a common rotation axis, and a bearing disposed between the outer ring and the inner ring.

[0020] Each roller body is housed in a respective recess and is movable along a first longitudinal axis. At least when the longitudinal axes are coaxially arranged and a circumferentially acting torque is transmitted during the intended operation of the tripod joint, forces can be transmitted continuously between the journal and the inner ring via (exactly) two contact points.

[0021] The roller body has, in particular, an outer ring and an inner ring, which are rotatable relative to each other. To achieve this, bearings (rolling elements, in this case needle-shaped rolling elements) are arranged between the inner and outer rings in a known manner. These bearings are arranged in the installation space of the inner or outer ring. A number of these bearings are arranged in the circumferential direction around the rotation axis.

[0022] Rotation of the inner ring relative to the outer ring allows the roller body to roll along a recess or track surface within the outer joint part, thereby allowing the inner joint part to be displaced along the first longitudinal axis relative to the outer joint part.

[0023] When the inner joint portion flexes, the roller body is further guided through the respective raceway surfaces, causing at least each journal to tilt relative to the respective roller body.

[0024] In particular, the roller body is guided by the recess in such a way that it cannot pivot relative to the recess.

[0025] Alternatively, when the inner joint portion bends, each roller body also tilts relative to each recess.

[0026] In addition to rotating relative to one another, the inner and outer rings are displaceable relative to one another along a common axis of rotation.

[0027] When the tripod joint is performing its intended operation, one of the inner and outer rings, together with the bearing, can be displaced along the axis of rotation relative to the other of the inner and outer rings.

[0028] The intended operation of the tripod joint (also called a joint) involves the inner and outer joint parts being positioned relative to one another for a specific application. For example, each roller body is positioned in a respective recess, and the joint operates only within a predetermined range of bending angles, for example, between 0 and 30° or between 0 and 26°. Furthermore, torques that the joint is deemed to tolerate are transmitted between the outer and inner joint parts, causing each roller body to displace only to a certain extent along the first longitudinal axis.

[0029] Unintended movements include, for example, the assembly of the joint or the assembly of the joint parts, including, for example, the positioning of each roller body on each journal.

[0030] In the present case, at least when the longitudinal axes are coaxially arranged and a circumferentially acting torque is transmitted during the intended operation of the tripod joint, the force can be transmitted continuously between the journal and the inner ring (or between each journal and each inner ring) via two contact points, which are arranged at a distance from each other along the radial direction in a cross section of the tripod joint extending transversely to the longitudinal axes.

[0031] Thus, in cross section, the first contact point is located further outward along the radial direction than the second contact point, which is closer to the central body or closer to the second longitudinal axis.

[0032] If the force is transmitted through (exactly) two contact points, the force can be transmitted more evenly distributed between the journal and the inner ring, in particular while preventing tilting of the inner ring relative to the axis of rotation or relative to the bearing and / or the outer ring. Likewise, the service life of the joint can be improved, since unacceptably high end loads are prevented.

[0033] In particular, the distance between the two contact points is at most about 2%, preferably at most 5%, and even at most about 10% of the smallest diameter of the inner ring, and in particular, this distance is at most about 30%, preferably at most 20%, and particularly preferably at most 15% of the smallest diameter of the inner ring.

[0034] The outer peripheral surface of the journal is preferably designed to be exclusively convexly curved, at least in cross section, in the region of at least two contact points (and therefore also between the two contact points), and in particular also has flat regions.

[0035] The inner peripheral surface of the inner ring is preferably designed to be exclusively concavely curved, at least in cross section, in the region of at least two contact points (and therefore also between the two contact points), and in particular also has flat regions.

[0036] In particular, even if the longitudinal axes are not coaxial and torques acting in the circumferential direction are transmitted during the intended operation of the tripod joint, forces can be continuously transmitted between the journal and the inner ring (or between each of the journals and each of the inner rings) via the two contact points.

[0037] In particular, as flexion changes and as the angle of rotation of the tripod joint changes, each contact point moves along the inner circumferential surface of the inner ring and along the outer circumferential surface of the journal, and therefore each contact point is not at a fixed point on the cross section, but rather moves along a radial direction (within that cross section) as a function of the angle of flexion and rotation.

[0038] In particular, the rotation angle is the circumferential position of each journal when the tripod joint rotates 360 degrees. When a tripod joint bent at a flexion angle greater than zero degrees rotates, the journal moves along the first longitudinal axis within the recess together with the roller body.

[0039] In particular, during the intended operation of a tripod joint, forces between the journal and the inner ring do not pass through only one contact point.

[0040] In particular, at least when the longitudinal axes are coaxially arranged, the two contact points are arranged equidistant from the PCR1 of the inner joint part along the radial direction.

[0041] In particular, PCR1 is the pitch radius of the inner joint portion, referred to herein as the first pitch radius (PCR1).

[0042] The pitch radius of the journal or of the inner joint part is the so-called effective radius. It is defined for an extended joint, i.e. for a joint with its longitudinal axes aligned coaxially with one another. The effective radius determines the lever arm of the resultant force when torque is transmitted. The pitch radius of the journal or of the inner joint part is therefore the radius emanating from the second longitudinal axis of the inner joint part, on which the centres of the respective sliding surfaces of the spherical trapezoid of the journal are located, for example, when the joint is extended.

[0043] The definition of pitch circle radius (also called PCR) is commonly known, especially for tripod joints.

[0044] In particular, at least when the longitudinal axes are arranged coaxially, the two contact points are arranged at different distances along the radial direction from the PCR1 of the inner joint part.

[0045] In particular, the first contact point, which is located further outwards, is located at a greater distance from the PCR1 than the second contact point.

[0046] In particular, in cross section, the contour of the outer circumferential surface of the journal is spherical (in particular convex spherical) at least between the contact points (or in the region of the contact points).

[0047] In particular, in cross section, the contour of the inner peripheral surface of the inner ring is formed in a pointed shape, an elliptical shape, or at least in a linear shape (preferably, by several straight lines) at least between the contact points (or in the region of the contact points).

[0048] In particular, the contour of the surface of the recess with which the outer ring can come into contact when the tripod joint is performing its intended operation is spherical.

[0049] In particular, in cross section, the contour of the surface of the outer ring that contacts the surface of the recess may be spherical, toroidal, barrel-shaped, rectilinear, saddle-shaped, bi-toroidal, or other shape.

[0050] In particular, in cross section, the contour of the surface of the recess, with which the outer ring can come into contact during the intended operation of the tripod joint, is adapted to guide said outer ring.

[0051] For example, if the outer ring of the roller body has a spherical outer contour on its outer periphery, the outer ring can be tilted around the central axis of the recess in the outer joint part in the circumferential direction of the central body. The recess in the outer joint part has a corresponding shape, so that the roller body is not fixed in the circumferential direction of the outer joint part, but can be tilted on both sides with respect to the center line of the recess in the orbital movement, particularly within a range of 0 to 5°, and particularly within a range of 0 to 3°. This tilt is called the orbital movement or orbital angle. The center line of the path is the axis of each recess in the outer joint part, and along this axis the roller body can move within the outer joint part as a result of the axial force.

[0052] In this case, the angular compensation of the orbital motion can also be effected at least partially between the journal and the inner ring, for which purpose the circumferential surface of the journal must be convexly curved.

[0053] The outer peripheral surface of the journal being convex means in particular that the outer peripheral surface is designed at least partially according to a frustum of a sphere, a barrel section, a donut section or a cylindrical section.

[0054] In particular, the PCR1 of the inner joint part and the PCR2 of the outer joint part are of the same size, at least when the longitudinal axes are coaxially arranged.

[0055] Alternatively, the PCR1 of the inner joint part is greater than or less than the PCR2 of the outer joint part, at least when the longitudinal axes are coaxially arranged.

[0056] In order to achieve particularly favorable guiding characteristics, an offset can be provided between the first pitch radius (PCR1) of the outer circumferential surface of each journal (i.e., of the inner joint portion) and the second pitch radius (PCR2) of each recess (i.e., of the outer joint portion).

[0057] The pitch radius of the outer joint part or of the recess is also the so-called effective radius, which is defined for an extended joint, i.e. when the longitudinal axes are aligned coaxially with one another. The effective radius determines the lever arm of the resultant force when torque is transmitted.

[0058] Therefore, the offset of each pitch radius is the difference between these pitch radii (PCR1-PCR2).

[0059] In particular, one of the inner and outer rings can be displaced along the axis of rotation together with the bearing relative to the other of the inner and outer rings.

[0060] In particular, the receiving space for the bearing on the outer or inner ring is delimited by at least one retaining ring arranged on the outer or inner ring, respectively. The receiving spaces on both sides of the bearing are delimited by retaining rings.

[0061] Further claimed herein is a motor vehicle equipped with at least one tripod joint according to the invention.

[0062] In particular, in the claims and in the restatements of these claims, the indefinite articles ("ein", "eine", "einer", "eines") are intended to be understood as they are, and not as numerals, and therefore the correspondingly introduced terms and elements are intended to be understood as occurring at least once, but in particular as possibly occurring several times.

[0063] For the avoidance of doubt, ordinal numbers ("first," "second," etc.) used herein primarily serve to distinguish (only) several similar objects, values, or steps; i.e., in particular, these ordinal numbers do not necessarily define any dependency or ordering of those objects, values, or steps relative to one another. Where a dependency or ordering is necessary, this will either be explicitly stated herein or will become apparent to those skilled in the art upon inspection of the actually described configuration. Where an element can occur more than once ("at least one"), a description of one of those elements may, but does not necessarily, apply equally to all or some of those elements.

[0064] In the following, the invention and the technical environment will be explained in more detail with reference to the attached drawings. It should be noted that the described design variations do not limit the invention. In particular, it should be noted that the drawings and in particular the depicted proportions are merely schematic. [Brief explanation of the drawings]

[0065] [Figure 1] 1 shows a known tripod joint in a tilted position, viewed along a first longitudinal axis and partially in cross section; [Figure 2] 2 shows a detail of the tripod joint in FIG. 1 in an enlarged configuration and in a cross-sectional view taken along the longitudinal axis. [Figure 3] 2 is shown in another view along the longitudinal axis. [Figure 4] 4 shows the detail of FIG. 3 in a first tilted position of the tripod joint. [Figure 5] 4 shows the detail of FIG. 3 in a second tilted position of the tripod joint. [Figure 6] 1 shows a detail of a tripod joint in cross section along the longitudinal axis. [Figure 7]The first design modification of the tripod joint is shown in detail in FIG. [Figure 8] The second design modification of the tripod joint is shown in detail in FIG. [Figure 9] The third design modification of the tripod joint is shown in detail in FIG. [Figure 10] The fourth design modification of the tripod joint is shown in detail in FIG. [Figure 11] The fifth design modification of the tripod joint is shown in detail in FIG. [Figure 12] The sixth design modification of the tripod joint is shown in detail in FIG. [Figure 13] The seventh design modification of the tripod joint is shown in detail in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0066] Figure 1 shows a known tripod joint 1 in a tilted position, viewed along a first longitudinal axis 3, and partially in cross section. Figure 2 shows a detail of the tripod joint 1 from Figure 1 in an enlarged arrangement and in cross section along the longitudinal axis 3, 8. Figure 3 shows the detail from Figure 2 in another view along the longitudinal axis 3, 8. Figure 4 shows the detail from Figure 3 in a first tilted position of the tripod joint 1. Figure 5 shows the detail from Figure 3 in a second tilted position of the tripod joint 1. Figures 1 to 5 are collectively explained below.

[0067] The tripod joint 1 comprises an outer joint part 2 having a first longitudinal axis 3 and a cavity 4 extending parallel to the first longitudinal axis 3 and having an open end 5. The outer joint part 2 is formed with three recesses 6 extending parallel to the first longitudinal axis 3. The tripod joint 1 further comprises an inner joint part 7 having a second longitudinal axis 8. The inner joint part 7 has a central body 9 on which three journals 10 are formed, each journal having a journal axis 12 extending radially outward from the second longitudinal axis 8 in a radial direction 11. A roller body 13 is arranged on each journal 10, and the roller body 13 has at least an outer ring 14, an inner ring 16 rotatable relative to the outer ring 14 about a common rotation axis 15, and bearings 17 (rolling elements, in this case, needle-shaped rolling elements) arranged between the outer ring 14 and the inner ring 16. The bearings 17 are arranged in a receiving space 29 of the outer ring 14. The receiving space 29 can also be formed by retaining rings 30 (see FIG. 7), in which case the bearings 17 are fixed by these retaining rings 30, and the outer ring 16 otherwise has, for example, a cylindrical surface. The bearings 17 are arranged circumferentially around the rotation axis 15.

[0068] Each roller body 13 is housed in a respective recess 6 and is movable along a first longitudinal axis 3. At least when the longitudinal axes 3, 8 are coaxially arranged and a torque acting in the circumferential direction 18 is transmitted during the intended operation of the tripod joint, forces (see arrows in Figures 3, 4, 5) can be transmitted continuously between the journal 10 and the inner ring 16 via exactly one contact point 19.

[0069] The rotation of the inner ring 16 relative to the outer ring 14 allows the roller body 13 to roll along the respective recesses 6 or raceways in the outer joint part 2, thereby allowing the inner joint part 7 to be displaced along the first longitudinal axis 3 relative to the outer joint part 2.

[0070] When the inner joint part 7 is bent, the roller body 13 is further guided by each recess 6 , so that at least each journal 10 is tilted relative to the respective roller body 13 .

[0071] When the inner joint part 7 is bent, each roller body 13 can also tilt to a small extent relative to each recess 6 .

[0072] In addition to rotating relative to one another, the inner and outer rings 16 and 14 are displaceable relative to one another along a common axis of rotation 15 .

[0073] The intended operation of the tripod joint 1 involves positioning the inner joint part 7 and the outer joint part 2 relative to one another for a particular application. For example, each roller body 13 is positioned in a respective recess 6, and the joint 1 operates only within a predetermined range of bending angles 32 (shown in FIG. 1 ), for example, between 0 and 30°, or between 0 and 26°. Furthermore, torques deemed to be tolerable by the joint 1 are transmitted between the outer joint part 2 and the inner joint part 7, causing each roller body 13 to displace only to a certain extent along the first longitudinal axis 3.

[0074] Unintended movements include, for example, the assembly of the joint 1 or the assembly of the joint parts, including, for example, the positioning of each roller body 13 on each journal 10 .

[0075] The inner joint part 7 has splines 33 on the central body 9 for connection to a shaft 34. The tripod joint 1 can be used in a motor vehicle 31 (shown here only), for example to connect shafts 43 between a differential gear and the drive wheels, in particular in the side shafts of the motor vehicle 31, which serve as drive connections (i.e., between the wheels and the drive unit).

[0076] 2 to 5 it can be seen that the inner ring 16 has a chamfer 35 on its end face facing the central body 9 of the inner joint part 7. This chamfer 35 serves to allow the roller body 13 to be attached to the journal 10. The presence of the chamfer 35 reduces the contact surface on the inner ring 16, which may result in unacceptably high end loads on the inner ring 16 during the intended operation of the tripod joint 1, which may result in a shortened service life.

[0077] In particular, when the tripod joint 1 operates at a bending angle 32, this contact point 19 can move along the axis of rotation 15 and can move along the contour of the inner circumferential surface 26 of the inner ring 16 or the contour of the outer circumferential surface 25 of the journal 10.

[0078] If this contact point 19 is located further outward along the radial direction 11, it will still be far from the edge of the surface of the inner circumferential surface 26 of the inner ring 16, which is intended to be in contact with the journal 10, thereby achieving regular and smooth power transmission (see Figure 4).

[0079] However, if this contact point 19 were located further inward along the radial direction 11, it could be located at one end of the surface of the inner circumferential surface 26 of the inner ring 16 that is intended to contact the journal 10, due to the shortened profile created by the chamfer 35. This could result in uneven power transmission and increased end loads.

[0080] For example, if the only contact point 19 between the outer peripheral surface 25 of the journal 10 and the inner peripheral surface 26 of the inner ring 16 is displaced further inward along the radial direction 11 toward the centerbody 9 (see FIG. 5), the inner ring 16 may tilt relative to the outer ring 14. This may exacerbate the problem of unacceptably high end loads.

[0081] The rotation angle 36 is the position of each journal 10 along the circumferential direction 18 when the tripod joint 1 rotates 360 degrees. When the tripod joint 1 bent at a bending angle 32 greater than zero degrees rotates, the journals 10 move along the first longitudinal axis 3 within the recess 6 together with the roller body 13. Here, the journal 10 located at the top is at a rotation angle 36 of zero degrees, the next journal 10 clockwise (bottom right) is at a rotation angle 36 of 120 degrees, and the journal 10 located at the bottom left is at a rotation angle 36 of 240 degrees.

[0082] FIG. 6 shows details of the tripod joint 1 in a cross-sectional view taken along the longitudinal axes 3 and 8. FIG. 7 shows details of FIG. 6 for a first design modification of the tripod joint 1. FIGS. 6 and 7 will be explained together below. Please refer to the explanations of FIGS. 1 to 5.

[0083] At least when the longitudinal axes 3, 8 are coaxially arranged and a torque acting in the circumferential direction 18 is transmitted during the intended operation of the tripod joint 1, the force (arrows in FIG. 6) can be transmitted continuously between the journal 10 and the inner ring 16 via exactly two contact points 19, 20. The contact points 19, 20 are arranged at a distance from each other along the radial direction 11 in a cross section 21 of the tripod joint 1 extending transversely to the longitudinal axes 3, 8.

[0084] The roller body 13 has an outer ring 14 and an inner ring 16, which are rotatable relative to each other. To achieve this, bearings 17 (rolling elements, in this case needle-shaped rolling elements) are arranged in a known manner between the inner ring 16 and the outer ring 14. These bearings 17 are arranged in the installation space 29 of the outer ring 14. A plurality of these bearings 17 are arranged around the rotation axis 15 in the circumferential direction.

[0085] When the tripod joint 1 is performing its intended operation, the inner ring 16 can be displaced along the axis of rotation 15 relative to the outer ring 14 and the bearing 17 .

[0086] In the cross section 21 , the first contact point 19 is located further outward along the radial direction 11 than the second contact point 20 , which is closer to the central body 9 or closer to the second longitudinal axis 8 .

[0087] If the force is transmitted via exactly the two contact points 19, 20, the force can be transmitted more evenly distributed between the journal 10 and the inner ring 16, and in particular while preventing tilting of the inner ring 16 relative to the axis of rotation 14 or relative to the bearing 17 and the outer ring 14. Likewise, the service life of the joint 1 can be improved, since unacceptably high end loads are prevented.

[0088] The distance between the two contact points 19 , 20 is approximately 10% of the smallest diameter of the inner ring 16 .

[0089] The outer peripheral surface 25 of the journal 10 is designed to be exclusively convexly curved, at least in the cross section 21, in the region of at least the two contact points 19, 20 (and therefore also between the two contact points 19, 20).

[0090] The inner peripheral surface 26 of the inner ring 16 is designed to be exclusively concavely curved, at least in the cross section 21, in the region of at least the two contact points 19, 20 (and therefore also between the two contact points 19, 20).

[0091] Even if the longitudinal axes 3, 8 are not coaxial and torque acting in the circumferential direction 18 is transmitted during the intended operation of the tripod joint 1, forces can be continuously transmitted between the journal 10 and the inner ring 16 (or between each of the journals 10 and each of the inner rings 16) via the two contact points 19, 20.

[0092] As the bending changes and depending on the angle of rotation of the tripod joint 1, the contact points 19, 20 move along the inner circumferential surface 26 of the inner ring 16 and along the outer circumferential surface 25 of the journal 10. Thus, the contact points 19, 20 are not at fixed points on the cross section 21, but rather move along the radial direction 11 (at that cross section 21) depending on the bending angle 32 and the angle of rotation.

[0093] 7 to 9, when at least the longitudinal axes 3, 8 are arranged coaxially, the two contact points 19, 20 are arranged equidistant 22, 23 from the PCR1 24 of the inner joint part 7 along the radial direction 11.

[0094] In FIG. 7, in cross section 21, the contour of the outer circumferential surface 25 of journal 10 is convex spherical at least between (or in the region of) contact points 19, 20.

[0095] In cross section 21, the profile of the inner peripheral surface 26 of inner ring 16 is pointed at least between (or in the region of) contact points 19, 20.

[0096] In the cross section 21, the contour of the surface 27 of the recess 6, with which the outer ring 14 can come into contact when the tripod joint 1 performs its intended operation, is pointed.

[0097] In cross section 21, the contour of the surface of outer ring 14 that contacts the surface of recess 6 is spherical.

[0098] At least when the longitudinal axes 3, 8 are coaxially arranged, the PCR1 24 of the inner joint part 7 and the PCR2 28 of the outer joint part 2 are of the same size.

[0099] 7 also shows a retaining ring 30 which limits the receiving space 29 for the bearing 17.

[0100] Fig. 8 shows details of Fig. 6 regarding a second design modification example of the tripod joint 1. Please refer to the explanations regarding Figs. 1 to 7.

[0101] In contrast to the first design variant, in cross section 21, the profile of the inner peripheral surface 26 of the inner ring 16 is elliptical at least between (or in the region of) contact points 19, 20, the major axis of which is tangent to PCR1 24 and parallel to the axis of rotation 15, at least when longitudinal axes 3, 8 are coaxially arranged.

[0102] Figure 9 shows details of Figure 6 for a third design modification of the tripod joint 1. See the description of Figure 8.

[0103] In contrast to the second design variant, in cross section 21 the contour of the inner circumferential surface 26 of the inner ring 16 is formed by two straight lines at least between the contact points 19, 20 (or in the region of the contact points 19, 20).

[0104] Fig. 10 shows details of Fig. 6 regarding a fourth design modification example of the tripod joint 1. Please refer to the explanations regarding Figs. 6 to 9.

[0105] In contrast to the first, second and third design variants, when at least the longitudinal axes 3, 8 are arranged coaxially, the two contact points 19, 20 are arranged at different distances 22, 23 along the radial direction 11 from the PCR1 24 of the inner joint part 7. In this case, the second distance 23 of the second contact point 20 from the PCR1 24 is shorter than the first distance 22 of the first contact point 19 from the PCR1 24. This also applies to the fifth embodiment in Figure 11 and the sixth embodiment in Figure 12.

[0106] In the fourth embodiment in FIG. 10, in cross section 21, the contour of the outer circumferential surface 25 of journal 10 is convex spherical at least between (or in the region of) contact points 19, 20.

[0107] In cross section 21, the profile of the inner peripheral surface 26 of inner ring 16 is pointed at least between (or in the region of) contact points 19, 20.

[0108] Figure 11 shows details of Figure 6 for a fifth design modification of the tripod joint 1. See the description of Figure 10.

[0109] In contrast to the fourth design variant, in cross section 21, the profile of the inner peripheral surface 26 of the inner ring 16 is elliptical at least between (or in the region of) contact points 19, 20, the major axis of this ellipse being inclined to PCR1 24 and to the axis of rotation 15, at least when longitudinal axes 3, 8 are coaxially arranged.

[0110] Figure 12 shows details of Figure 6 for a sixth design modification of the tripod joint 1. See the description of Figure 11.

[0111] In contrast to the fifth embodiment, in cross section 21, the profile of the inner circumferential surface 26 of the inner ring 16 is formed by three straight lines at least between (or in the region of) the contact points 19, 20.

[0112] Figure 13 shows details of Figure 6 for a seventh design modification of the tripod joint 1. See the explanation for Figure 7.

[0113] In the seventh design variant according to FIG. 13, in cross section 21, the contour of the outer circumferential surface 25 of journal 10 is convex spherical at least between (or in the region of) contact points 19, 20.

[0114] In cross section 21, the profile of the inner peripheral surface 26 of inner ring 16 is pointed at least between (or in the region of) contact points 19, 20.

[0115] In order to achieve particularly favorable guiding properties, an offset can be provided between the first pitch radius (PCR1 24) of the outer circumferential surface 25 of each journal 10 (i.e. of the inner joint part 7) and the second pitch radius (PCR2 28) of each recess 6 (i.e. of the outer joint part 2).

[0116] In contrast to the aforementioned design variant, at least when the longitudinal axes 3, 8 are coaxially arranged, the PCR1 24 of the inner joint part 7 and the PCR2 28 of the outer joint part 2 are different in size, with the PCR1 24 of the inner joint part 7 being smaller than the PCR2 28 of the outer joint part 2. [Explanation of symbols]

[0117] 1 Tripod joint 2 Outer joint part 3 First longitudinal axis 4 cavities 5 End 6 recess 7 Inner joint part 8 Second Longitudinal Axis 9 Centrosome 10 Journals 11 Radial 12 Journal shaft 13 Roller body 14 outer ring 15 Rotation axis 16 Inner Circle 17 Supporting body 18 Circumferential direction 19 First Contact Point 20 Second Contact Point 21 Cross Section 22 First Distance 23 Second Distance 24 PCR1 (pitch circle radius) 25 Outer surface 26 Inner surface 27 Surface 28 PCR2 29 Containment Space 30 retaining ring 31 Automobiles 32 Bending angle 33 Spline 34 Shaft 35 Chamfered part 36 rotation angle

Claims

1. A tripod joint (1), An outer joint part (2) having a first longitudinal axis (3) and a cavity (4) extending parallel to said first longitudinal axis (3) and having an open end (5), Three recesses (6) are formed extending parallel to the first longitudinal axis (3), an outer joint part (2); an inner joint part (7) having a second longitudinal axis (8) and having at least one central body (9), The central body (9) is formed with three journals (10) having journal axes (12) extending radially (11) outward from the second longitudinal axis (8). Inner joint part (7) and Equipped with A roller body (13) is disposed on each of the journals (10), The roller body (13) has at least one outer ring (14), an inner ring (16) rotatable relative to the outer ring (14) around a common rotation axis (15), and a bearing (17) disposed between the outer ring (14) and the inner ring (16); Each of the roller bodies (13) is disposed in each recess (6) so as to be movable along a first longitudinal axis (3); at least when the longitudinal axes (3, 8) are coaxially arranged and a torque acting in a circumferential direction (18) is transmitted during the intended operation of the tripod joint (1), forces can be transmitted continuously between the journal (10) and the inner ring (16) via two contact points (19, 20); the contact points (19, 20) are spaced apart from one another along the radial direction (11) in a cross section (21) of the tripod joint (1) extending transversely to the longitudinal axes (3, 8); Tripod joint (1).

2. A tripod joint (1) according to claim 1, when at least the longitudinal axes (3, 8) are coaxially arranged, the two contact points (19, 20) are arranged equidistantly (22, 23) from the PCR1 (24) of the inner joint part (7) along the radial direction (11); Tripod joint (1).

3. A tripod joint (1) according to claim 1, at least when the longitudinal axes (3, 8) are coaxially arranged, the two contact points (19, 20) are arranged at different distances (22, 23) from the PCR1 (24) of the inner joint part (7) along the radial direction (11); Tripod joint (1).

4. A tripod joint (1) according to any one of claims 1 to 3, In the cross section (21), the contour of the outer peripheral surface (25) of the journal (10) is spherical at least between the contact points (19, 20). Tripod joint (1).

5. A tripod joint (1) according to any one of claims 1 to 4, In the cross section (21), the profile of the inner peripheral surface (26) of the inner ring (16) is pointed, elliptical, or at least linear, at least between the contact points (19, 20). Tripod joint (1).

6. A tripod joint (1) according to any one of claims 1 to 5, the contour of the surface (27) of the recess (6) in the cross section (21), with which the outer ring (14) can contact during the intended operation of the tripod joint (1), is spherical; Tripod joint (1).

7. A tripod joint (1) according to any one of claims 1 to 6, the PCR1 (24) of the inner joint part (7) is greater than or less than the PCR2 (28) of the outer joint part (2), at least when the longitudinal axes (3, 8) are coaxially arranged; Tripod joint (1).

8. A tripod joint (1) according to any one of claims 1 to 7, Either the inner ring (16) or the outer ring (14) can be displaced along the rotation axis (15) together with the support body (17) relative to the other of the inner ring (16) and the outer ring (14). Tripod joint (1).

9. A tripod joint (1) according to any one of claims 1 to 8, the receiving space (29) for the bearing (17) on the outer ring (14) or the inner ring (16) is delimited by a retaining ring (30) arranged on the outer ring and the inner ring (14, 16), respectively; Tripod joint (1).

10. A motor vehicle (31) comprising at least one tripod joint (1) according to any one of claims 1 to 9.

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