Tripod spider and tripod joint

Abstract

A tripod spider and a tripod joint. The tripod spider comprises: a body (10), three journals (20) arranged on the body (10), and transition connecting necks (30) for connecting the journals (20) to the body (10). The body (10) comprises a plurality of connecting portions (11) connected to each other in sequence and enclosing an annular structure, the center of the annular structure being a shaft hole (14) running through the body (10); two ends of each connecting portion (11) are each connected to a journal (20), each connecting portion (11) comprising a plurality of sub-connecting portions (111); and four sub-connecting portions (111) converge at the central axis of the connecting portion (11), every two adjacent sub-connecting portions (111) being symmetrically arranged. Each sub-connecting portion (111) comprises an inner side surface which faces the shaft hole (14) and an outer side surface which is arranged opposite the inner side surface, and each outer side surface extends from the central axis of the connecting portion (11) towards the journal (20) connected to the sub-connecting portion (111) where said outer side surface is located, and gradually approaches the inner side surface of the connecting portion (11) during extension. Thus, the problems of a small swing angle, poor torque bearing capacity and excessive weight in tripod joints are solved.

Description

A tripod bracket and tripod universal joint Technical Field

[0001] The present invention relates to the technical field of automobile transmission, in particular to a tripod rack and a tripod universal joint. Background Art

[0002] High-performance constant velocity universal joint (CVJ) drive shaft assemblies for passenger cars typically consist of fixed universal joints, sliding universal joints, and an intermediate shaft connecting the joints. Sliding universal joints include tripod and six-ball types, with tripod sliding joints being the most common type in the market. Triple-joint CVJs are key components in automotive chassis transmission systems and are commonly used at the moving end of a constant velocity drive shaft assembly. The driving and driven shafts connected to the CVJs rotate at constant angular velocities, transmitting torque to enable vehicle movement.

[0003] A tripod universal joint typically consists of a tripod and a roller mounted on the tripod. The roller is mounted on the tripod's journal and can swing around the journal. In the prior art, the outer surface of the tripod's main body is typically spherical. This spherical structure partially limits the roller's range of motion, resulting in a smaller swing range. Furthermore, the main body is not uniformly stressed in actual use. Consequently, the tripod's main body contains redundant material, which has no positive effect on torque-carrying capacity. This results in inefficient material utilization, reduced torque-carrying capacity, and increased weight. Summary of the Invention

[0004] In order to solve the problems of small swing angle, poor torque bearing capacity and heavy weight of the tripod universal joint, the present invention provides a tripod bracket and a tripod universal joint.

[0005] A first aspect of the present invention provides a tripod bracket, comprising:

[0006] A main body, three shaft necks arranged on the main body and a transition connecting neck for connecting the shaft necks and the main body; wherein, the main body includes a plurality of connecting parts that are connected in sequence and enclosed in an annular structure, the center of the annular structure is an axial hole arranged through the main body, both ends of the connecting part are connected to the shaft necks, the connecting part includes a plurality of sub-connecting parts, the four sub-connecting parts intersect on the central axis of the connecting part, and the two adjacent sub-connecting parts are symmetrically arranged; wherein, the sub-connecting part includes an inner side surface facing the axial hole and an outer side surface arranged opposite to the inner side surface, the outer side surface extends from the central axis of the connecting part toward the shaft neck connected to the sub-connecting part where it is located, and gradually approaches the inner side surface of the connecting part during the extension process.

[0007] In some embodiments, the curve where the outer side surface of the sub-connecting portion intersects with the first symmetry plane is the first curve. The first curve extends from the center axis to the journal. The first curve includes multiple sub-curves that are smoothly connected in sequence. The sub-curves are circular arcs, and the curvature radius of the multiple sub-curves gradually decreases with the extension direction of the first curve; wherein the first symmetry plane is a plane that symmetrically divides the connecting portion along the width direction of the main body.

[0008] In some embodiments, the first curve includes a first sub-curve and a second sub-curve, the first end of the first sub-curve intersects the central axis of the connecting portion, and the second end of the first sub-curve is connected to the first end of the second sub-curve.

[0009] In some embodiments, a ratio of a radius of curvature of the first sub-curve to a radius of curvature of the second sub-curve is greater than or equal to 1.30 and less than or equal to 1.60.

[0010] In some embodiments, the curve where the sub-connecting portion intersects the second symmetry plane is a second curve, the second curve is a circular arc, and the curvature radius of the second curve is less than or equal to the maximum value of the curvature radii of multiple sub-curves; the second symmetry plane is a plane including the axis of the shaft hole and the central axis of the connecting portion.

[0011] In some embodiments, the curve where the sub-connection parts of two adjacent connection parts intersect at the shaft neck is a third curve, and the third curve is an arc line, wherein the curvature radius of the third curve is greater than the curvature radius of the second curve, and the second curve and the third curve have different centers respectively.

[0012] In some embodiments, the body includes a first plane and a second plane, the first plane is located on the front side of the body, and the second plane is located on the rear side of the body. The first plane and the second plane are arranged back to back and parallel to each other; the curve where the sub-connection part intersects with the first plane or the second plane is a fourth curve, and the fourth curve gradually extends from a position away from the shaft neck to a position close to the shaft neck, and its curvature radius gradually decreases during the extension process of the fourth curve.

[0013] In some embodiments, the fourth curve is an elliptical arc, and a ratio between a maximum value of the curvature radius and a minimum value of the curvature radius is greater than or equal to 0.90 and less than or equal to 0.99.

[0014] In some embodiments, the cross-section of the transition connection neck along a plane perpendicular to its central axis is elliptical, the width direction of the body is a first direction, and a second direction perpendicular to the first direction is provided on the cross-section. The axis extending along the first direction in the cross-section is the second axis, which is the major axis of the ellipse, and the axis extending along the second direction in the cross-section is the first axis, which is the minor axis of the ellipse.

[0015] The second aspect of the present invention further provides a tripod universal joint, comprising a tripod bracket according to any embodiment of the first aspect, and a roller, a needle roller, a baffle and an elastic retaining ring sleeved on the journal.

[0016] To solve the problems of small swing angle, poor torque bearing capacity and heavy weight of tripod universal joint, the present invention has the following advantages:

[0017] Since part of the edge of the roller mounted on the journal will be close to the outer side of the body during operation, by adopting the connection part composed of multiple sub-connections in the above-mentioned technical solution in this application, the outer side of the sub-connection part gradually approaches the inner side in the process of extending toward the journal part, and the inner side is actually the axial hole at the center of the body, so that the outer side of the body located near the journal is relatively thinner. On the one hand, it can make the roller mounted on the journal have a larger swing space, and on the other hand, it can make the stress distribution more uniform, so that the material is fully utilized, and it can have torque bearing capacity at the same weight, and reduce redundant materials. In addition, due to the structural design here, the overall mass of the tripod can be reduced to a certain extent, thereby achieving the purpose of lightweighting. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 shows a schematic structural diagram of a tripod bracket according to an embodiment;

[0019] FIG2 shows a front view of a tripod bracket according to an embodiment;

[0020] FIG3 shows a side view of a tripod bracket according to an embodiment;

[0021] FIG4 shows a cross-sectional view along CC in FIG2 ;

[0022] FIG. 5 shows a cross-sectional view along line BB in FIG. 2 .

[0023] Figure markings: 10-main body; 11-connecting part; 111-sub-connecting part; 12-first plane; 13-second plane; 14-axial hole; 20-shaft neck; 21-first axis; 22-second axis; 30-transition connecting neck; 40-first symmetry plane; 50-second symmetry plane; 60-first curve; 61-first sub-curve; 62-second sub-curve; 70-second curve; 80-third curve; 90-fourth curve. DETAILED DESCRIPTION

[0024] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the present disclosure, rather than to imply any limitation on the scope of the present disclosure.

[0025] As used herein, the term "including" and its variations are to be interpreted as open-ended terms meaning "including, but not limited to." The term "based on" is to be interpreted as "based, at least in part, on." The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment." The term "another embodiment" is to be interpreted as "at least one other embodiment." Terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "vertical," "horizontal," "transverse," and "longitudinal" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily intended to better describe the present application and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientation or positional relationships. For example, the term "on" may, in certain circumstances, be used to indicate a dependency or connection relationship. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances. Furthermore, the terms "installed," "disposed," "provided with," "connected," and "connected" are to be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise specified, "plurality" means two or more.

[0026] This embodiment discloses a tripod bracket, as shown in FIG1 , which may include:

[0027] A body 10, three journals 20 provided on the body 10, and a transition connecting neck 30 for connecting the journals 20 and the body 10; wherein the body 10 includes a plurality of connecting portions 11 sequentially connected to form an annular structure, the center of the annular structure being an axial hole 14 provided through the body 10, the connecting portion 11 being connected to the journals 20 at both ends, and the connecting portion 11 including a plurality of sub-connecting portions 111, the four sub-connecting portions 111 intersecting on the central axis of the connecting portion 11, and two adjacent sub-connecting portions 111 being symmetrically arranged;

[0028] Among them, the sub-connection part 111 includes an inner side surface facing the axial hole 14 and an outer side surface arranged opposite to the inner side surface. The outer side surface extends from the central axis of the connection part 11 toward the shaft neck 20 connected to the sub-connection part 111 where it is located, and gradually approaches the inner side surface of the connection part 11 during the extension process.

[0029] It should be noted that the journal 20 typically has an arcuate surface and is provided with a roller capable of swinging relative to the surface of the journal 20. During relative rotation, the edge of the roller approaches the outer surface of the body 10, and therefore, its swing angle is limited by the distance between the edge of the roller and the outer surface of the body 10. Furthermore, the outer surface of the body 10 typically has a spherical structure, meaning that the outer surface of the connecting portion 11 typically forms a portion of a sphere, with the center of the sphere located on the central axis of the tripod. An axial hole 14 is provided at the central axis of the body 10, extending through the body 10. Therefore, the body 10 is annular in shape. A bearing bracket or other structure may be provided at the axial hole 14, and the sidewall of the axial hole 14 may constitute the inner surface of the body 10. The journal 20 is provided with three journals evenly distributed along the circumferential direction of the outer surface of the body 10. Therefore, the body 10 may also have three connecting portions 11, which are sequentially connected and enclosed in a ring. The transition neck 30 is used to transitionally connect the journal 20 and the body 10, and the transition neck 30 can be set to a structure that converges slightly inward relative to the journal 20 along the circumferential direction, which can form a larger space for the roller to swing than the traditional structure.

[0030] In this embodiment, as shown in Figures 1 and 2, the connection portion 11 may have a central axis, and the connection portion 11 is a curved surface with a uniform transition. Therefore, the dotted line in Figure 1 is not an actual structural line, but a virtual line constructed to facilitate understanding of this solution. As shown in Figure 1, the connection portion 11 is divided into four sub-connections 111, and the four sub-connections 111 intersect at the above-mentioned central axis, and two adjacent sub-connections 111 are symmetrical structures, that is, the connection portion 11 can be equally divided into four sub-connections 111, and the outer side surfaces of the sub-connections 111 extend from the central axis toward the shaft neck 20 connected thereto, and gradually approach the inner side surface of the connection portion 11 during the extension process, and the inner side surface is actually the shaft hole 14 at the center of the body 10, that is, the closer each sub-connection portion 111 is to the shaft neck 20, the thinner its thickness. Overall, compared with the traditional spherical surface, this embodiment Body 10. In this embodiment, the body 10 in the peripheral area of ​​the journal 20 is closer to the inner side surface relative to the central axis of the connecting portion 11. This arrangement, on the one hand, increases the space between the edge of the roller and the outer surface of the body 10, thereby enabling the roller mounted on the journal 20 to have a larger swing space; on the other hand, it makes the stress distribution more uniform, so that the material is fully utilized and redundant materials are reduced, and a greater torque can be carried under the same volume and weight. In addition, due to the structural design here, the overall mass of the tripod can be reduced to a certain extent, thereby achieving the purpose of lightweighting.

[0031] Furthermore, as an optional embodiment, as shown in FIG1 , the curve where the outer side surface of the sub-connecting portion 111 intersects the first symmetry plane 40 is a first curve 60 . The first curve 60 extends from the central axis toward the journal 20 . The first curve 60 includes a plurality of sub-curves that are smoothly connected in sequence. The sub-curves are circular arcs, and the curvature radius of the plurality of sub-curves gradually decreases along the extension direction of the first curve 60 .

[0032] The first symmetry plane 40 is a plane that symmetrically divides the connecting portion 11 along the width direction of the body 10 .

[0033] In this embodiment, the width direction of the body 10 refers to the direction from the front to the back of the body 10, as shown in Figure 3. The dotted line in the figure represents a plane perpendicular to the viewing angle, not an actual construction line. The first symmetry plane 40 is a virtual plane, not an actual structural plane. The first symmetry plane 40 can divide the body 10 into two symmetrical parts along the width direction. As shown in Figure 1, the curve where the sub-connection portion 111 intersects the first symmetry plane 40 is the first curve 60. By dividing the first curve 60 into multiple sub-curves, each of which is an arc, the curvature radius of the sub-curve can be controlled to control the change trend of the outer surface of the sub-connection portion 111 in this direction, which is relatively easy to achieve in actual processing. By controlling the curvature radius of the multiple sub-curves to gradually decrease along the extension direction of the first curve 60, the outer surface of the sub-connection portion 111 closer to the journal 20 is closer to the inner side. Such a structural design can make the stress distribution more uniform, reduce stress concentration, and improve product strength.

[0034] In some embodiments, as shown in Figure 1, the first curve 60 includes a first sub-curve 61 and a second sub-curve 62, the first end of the first sub-curve 61 intersects the central axis of the connecting portion 11, and the second end of the first sub-curve 61 is connected to the first end of the second sub-curve 62.

[0035] As a preferred embodiment, by dividing the first curve 60 into a two-section structure of a first sub-curve 61 and a second sub-curve 62, the difficulty of processing and design can be reduced. The lengths of the first sub-curve 61 and the second sub-curve 62 can be set to be the same or similar, thereby ensuring that the body 10 has good structural strength while also ensuring that the roller can have a large swing angle.

[0036] As a specific implementation, the ratio of the curvature radius of the first sub-curve 61 to the curvature radius of the second sub-curve 62 is greater than or equal to 1.30 and less than or equal to 1.60, and is preferably set to 1.45.

[0037] In this embodiment, by controlling the ratio of the curvature radii of the first sub-curve 61 and the second sub-curve 62 , the technical solution of the present application can be adaptively applied to tripods of various sizes.

[0038] In some embodiments, as shown in Figure 1, the curve where the sub-connecting portion 111 intersects the second symmetry plane 50 is a second curve 70, the second curve 70 is a circular arc, and the curvature radius of the second curve 70 is less than or equal to the maximum value of the curvature radius of multiple sub-curves; the second symmetry plane 50 is a plane including the axis of the shaft hole 14 and the central axis of the connecting portion 11.

[0039] Among them, the second symmetry plane 50 is shown in Figure 2. The dotted line in the figure represents a plane perpendicular to the viewing angle, not an actual construction line. The second symmetry plane 50 is a virtual plane, not an actual structural plane. As shown in the figure, the second symmetry plane 50 is a plane formed by the axis of the shaft hole 14 of the body 10 and the central axis of the connecting portion 11. The second symmetry plane 50 can symmetrically divide the connecting portion 11 and the journal 20 arranged opposite to the connecting portion 11 at the same time. The second curve 70 is actually the position on the outer surface of the connecting portion 11 that is farthest from the journals 20 arranged at both ends. This position has basically no effect on the swing of the roller. Therefore, for higher structural strength, the curvature radius of the second curve 70 can be equal to the maximum curvature radius of multiple sub-curves, that is, as shown in Figure 1, the curvature radius of the second curve 70 can be equal to the curvature radius of the first sub-curve 61. The end of the second curve 70 away from the central axis, that is, the middle part of the connecting part 11 close to the front side or the rear side, is not a weak part of the structure, and the stress condition is relatively good in actual application. In order to further reduce the weight of the main body 10, the curvature radius of the second curve 70 can be selected to be slightly smaller than the curvature radius of the first sub-curve 61, so that the thickness of the part of the main body 10 close to the front side or the rear side is slightly reduced. When the structural strength is basically the same, the weight of the main body 10 is slightly reduced, thereby improving the uniformity of stress distribution while improving material utilization and reducing redundant materials.

[0040] As a further embodiment, as shown in Figure 1, the curve where the sub-connection parts 111 of two adjacent connection parts 11 intersect at the shaft neck 20 is a third curve 80, and the third curve 80 is an arc line, wherein the curvature radius of the third curve 80 is greater than the curvature radius of the second curve 70, and the second curve 70 and the third curve 80 have different centers respectively.

[0041] In this embodiment, the third curve 80 actually intersects at the journal 20. Therefore, while it may not actually be generated on the outer surface of the body 10, the third curve 80 still exists within the structure. By making the radius of curvature of the third curve 80 larger than that of the second curve 70, the outer surface of the body 10 at the journal 20 becomes flatter, thereby increasing the swing angle of the roller mounted on the journal 20. However, because the radius of curvature of the third curve 80 is larger than that of the second curve 70 and its position relative to the central axis of the connecting portion 11 is closer to the inner surface, the second curve 70 and the third curve 80 have different centers, and the center of the third curve 80 is further away from the outer surface of the sub-connecting portion 111. At the same time, such a structural design makes the main body 10 in the peripheral area of ​​the journal 20 converge more smoothly relative to the central axis of the connecting portion 11, thereby further increasing the space between the edge of the roller and the outer surface of the main body 10, thereby enabling the roller mounted on the journal 20 to have a larger swing space. On the other hand, it makes the stress distribution more uniform, makes full use of the material, and reduces redundant materials, so that it can carry a greater torque at the same volume and weight. In addition, due to the structural design here, the overall mass of the tripod can be further reduced, thereby achieving the purpose of lightweighting. In some embodiments, as shown in Figures 1, 3 and 4, the main body 10 includes a first plane 12 and a second plane 13, the first plane 12 is located on the front side of the main body 10, and the second plane 13 is located on the rear side of the main body 10, and the first plane 12 and the second plane 13 are arranged back to back and parallel to each other; the curve where the sub-connection portion 111 intersects with the first plane 12 or the second plane 13 is a fourth curve 90, and the fourth curve 90 gradually extends from a position away from the shaft neck 20 to a position close to the shaft neck 20, and its curvature radius gradually decreases during the extension process of the fourth curve 90.

[0042] In this embodiment, as shown in Figures 1, 2, 3, and 4, the first plane 12 and the second plane 13 are actually two symmetrical planes located on the front and rear sides of the body 10, respectively, and are generally used for installation and positioning. The sub-connecting portion 111 will intersect with one of the first plane 12 or the second plane 13. Figure 1 shows a situation where one of the sub-connecting portions 111 intersects with the first plane 12. The intersecting curve is the fourth curve 90. The fourth curve 90 gradually extends from a position away from the journal 20 to a position close to the journal 20 and eventually intersects with another fourth curve 90. That is, as the fourth curve 90 extends from the intersection point of the fourth curve 90 with the second curve 70 toward the journal 20, the curvature radius of the fourth curve 90 gradually decreases. As shown in Figure 4, D1 represents the distance from the axis of the shaft hole 14 to the starting point of the fourth curve 90, and D2 represents the distance from the axis of the shaft hole 14 to the end point of the fourth curve 90, where D1 is greater than D2. With this arrangement, the material around the journal 20 is less than that at the center of the connection portion 11, thereby further improving material utilization, reducing redundant materials, and increasing the swing angle of the roller while improving the uniformity of stress distribution.

[0043] In addition, bosses extending outward along the axial direction of the shaft hole 14 may be provided on the first plane 12 and the second plane 13 as needed to facilitate the matching or installation with other components.

[0044] In order to avoid excessive changes in the fourth curve 90, which may cause the structure of the main body 10 located at the journal 20 to be too weak, or excessive material in the central area of ​​the connecting part 11 to cause material redundancy, as a specific embodiment, the fourth curve 90 is an elliptical arc, and the ratio between the maximum value of its curvature radius and the minimum value of its curvature radius is greater than or equal to 0.90 and less than or equal to 0.99, preferably, it is set to 0.97.

[0045] In order to increase the stress strength at the transition connection neck 30, as shown in Figure 5, the cross-section of the transition connection neck 30 along a plane perpendicular to its central axis is an ellipse, the width direction of the main body 10 is a first direction, and a second direction perpendicular to the first direction is provided on the cross-section. The axis extending along the first direction in the cross-section is the second axis 22, which is the major axis of the ellipse, and the axis extending along the second direction in the cross-section is the first axis 21, which is the minor axis of the ellipse.

[0046] The second axis 22 and first axis 21, represented by dashed lines in Figure 5, are not actual construction lines but virtual structural lines to facilitate understanding of the technical solution. During the roller's oscillation, when it swings from side to side along its length (i.e., the direction of the first axis 21 in the figure), a force is generated along its length on the journal 20 and transition neck 30. The direction of the force is the direction of the first axis 21 in the figure, and this operating condition is common. To enhance structural strength while using essentially the same materials, the transition neck 30 is elliptical, with its second axis 22 perpendicular to the direction of the force. This allows the force to be shared by more material, reducing the force concentration effect and effectively improving structural strength.

[0047] In addition, the ratio of the second axis 22 to the first axis 21 can be set to be greater than 1 and less than or equal to 1.1.

[0048] As an optional embodiment, the transition connection neck 30 can be composed of multiple arcs in sequence along the axial direction, and can include at least a lower part connected to the connecting portion 11 and an upper part connected to the shaft neck 20. Since the transition connection neck 30 can be set to an elliptical shape, the circumferential direction can also be connected in sequence using multiple arcs. Specifically, the lower part of the transition connection neck 30 is composed of multiple arc surfaces that are concave in the axial direction, and the arc surfaces are smoothly transitioned to each other. The arc radius of the cross-sectional shape of the lower part where it intersects with the first symmetry plane 40 is R1, and the arc radius of the cross-sectional shape of the lower part closest to the first plane 12 or the second plane 13 is R2. R1 is greater than R2, thereby further reducing the stress concentration phenomenon here and improving the structural strength. As a specific embodiment, the radius of the arc connected to the body 10 can be set to 2.5mm-4.5mm, and the arc connected to the shaft neck 20 can be equal to or slightly smaller than the radius of the arc connected to the body 10.

[0049] The tripod in a preferred embodiment of the present application was modeled and subjected to finite element analysis, and the results showed that the overall stress distribution is more uniform, and the contribution of the material is better, redundant materials are reduced, and a greater torque can be carried at the same volume and weight. At the same time, the swing angle of the roller at the journal 20 can also be increased.

[0050] The second aspect of the present application further discloses a tripod universal joint, which includes a tripod bracket according to any embodiment of the first aspect, and a roller, a needle roller, a baffle and an elastic retaining ring sleeved on the journal 20.

[0051] In this embodiment, the tripod in the above technical solution can, on the one hand, provide the roller mounted on the journal 20 with a larger swinging space, and on the other hand, make the stress distribution more uniform, so that the material can be fully utilized, and the torque bearing capacity can be achieved at the same weight, and redundant materials can be reduced. In addition, since the main body is reduced to a certain extent here, the overall mass of the tripod universal joint can be reduced to a certain extent, thereby achieving the purpose of lightweighting.

[0052] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present disclosure, and that in actual applications, various changes may be made thereto in form and detail without departing from the scope of the present disclosure.

Claims

1. A tripod bracket, characterized in that: The tripod bracket comprises: A body, three journals provided on the body, and a transition connecting neck for connecting the journals and the body; wherein the body includes a plurality of connecting portions sequentially connected to form an annular structure, the center of the annular structure being an axial hole provided through the body, the two ends of the connecting portion being connected to the journals, the connecting portion including a plurality of sub-connecting portions, four of the sub-connecting portions intersecting on the central axis of the connecting portion, and two adjacent sub-connecting portions being symmetrically arranged; In which, the sub-connection part includes an inner side surface facing the axial hole and an outer side surface arranged opposite to the inner side surface. The outer side surface extends from the central axis of the connection part toward the shaft neck connected to the sub-connection part where it is located, and gradually approaches the inner side surface of the connection part during the extension process.

2. A tripod according to claim 1, characterized in that: A curve where the outer side surface of the sub-connecting portion intersects the first symmetry plane is a first curve, the first curve extending from the central axis toward the journal, the first curve comprising a plurality of sub-curves smoothly connected in sequence, the sub-curves being circular arcs, and the curvature radii of the plurality of sub-curves gradually decreasing along the extension direction of the first curve; The first symmetry plane is a plane that symmetrically divides the connecting portion along the width direction of the body.

3. A tripod according to claim 2, characterized in that: The first curve includes a first sub-curve and a second sub-curve. The first end of the first sub-curve intersects the central axis of the connecting portion, and the second end of the first sub-curve is connected to the first end of the second sub-curve.

4. A tripod according to claim 3, characterized in that: A ratio of a curvature radius of the first sub-curve to a curvature radius of the second sub-curve is greater than or equal to 1.30 and less than or equal to 1.

60.

5. The tripod bracket according to claim 2, characterized in that: The curve where the sub-connection portion intersects the second symmetry plane is a second curve, the second curve is an arc line, and the curvature radius of the second curve is less than or equal to the maximum value of the curvature radii of the multiple sub-curves; The second symmetry plane is a plane including the axis of the shaft hole and the central axis of the connecting portion.

6. The tripod bracket according to claim 5, characterized in that: The curve where the sub-connecting parts of two adjacent connecting parts intersect at the shaft neck is a third curve, and the third curve is an arc line, wherein the curvature radius of the third curve is greater than the curvature radius of the second curve, and the second curve and the third curve have different centers respectively.

7. The tripod bracket according to claim 1, characterized in that: The body includes a first plane and a second plane, the first plane is located at the front side of the body, the second plane is located at the rear side of the body, and the first plane and the second plane are arranged opposite to each other and parallel to each other; The curve where the sub-connection portion intersects the first plane or the second plane is a fourth curve. The fourth curve gradually extends from a position away from the shaft neck to a position close to the shaft neck. During the extension of the fourth curve, its curvature radius gradually decreases.

8. The tripod bracket according to claim 7, characterized in that: The fourth curve is an elliptical arc, and the ratio between the maximum value of the curvature radius and the minimum value of the curvature radius is greater than or equal to 0.90 and less than or equal to 0.

99.

9. The tripod bracket according to claim 1, characterized in that: The cross-section of the transition connection neck along a plane perpendicular to its central axis is an ellipse, the width direction of the body is a first direction, a second direction perpendicular to the first direction is provided on the cross-section, the axis extending along the first direction in the cross-section is the second axis, which is the major axis of the ellipse, and the axis extending along the second direction in the cross-section is the first axis, which is the minor axis of the ellipse.

10. A tripod universal joint, characterized in that: The tripod universal joint comprises the tripod bracket described in any one of claims 1 to 9, and a roller, a needle roller, a baffle and an elastic retaining ring sleeved on the journal.

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