1. The utility model provides a high life convexity cross, includes central axis body (1) and four spindle nose (2), its characterized in that: the shaft head (2) is of a two-section structure and comprises a linear radial shaft section (21) connected with the heel of the central shaft body (1) and an arc-shaped radial shaft section (22) connected with the linear radial shaft section (21), and the outer diameter of the arc-shaped radial shaft section (22) is gradually reduced from a boundary between the arc-shaped radial shaft section (22) and the linear radial shaft section (21) to the other end of the arc-shaped radial shaft section (22).

2. A high life convexity cross as recited in claim 1, wherein: the arc-line-shaped radial shaft section (22) is an outer convex arc.

3. A high life convexity cross as recited in claim 1, wherein: the end part of the shaft head (2) is also provided with an end face chamfer angle (23), and the outer diameter of the arc-shaped radial shaft section (22) is gradually reduced from the boundary between the arc-shaped radial shaft section (22) and the linear radial shaft section (21) to the boundary between the arc-shaped radial shaft section (22) and the end face chamfer angle (23).

4. A high life convexity cross as recited in claim 3, wherein: the axial length of the linear radial-axial section (21) is A, the axial length sum of the arc radial-axial section (22) and the end face chamfer angle (23) is B, and A is equal to B.

5. A high life convexity cross as recited in any of claims 1-4, wherein: the outer diameter of the large-diameter end of the arc-shaped radial-axial section (22) is the same as that of the linear radial-axial section (21), and the outer diameter of the small-diameter end of the arc-shaped radial-axial section (22) is 0.01-0.04 mm smaller than that of the large-diameter end of the arc-shaped radial-axial section.

[ background of the invention ]

The universal joint cross is an important part on a universal joint cross shaft, four shaft heads of a common cross shaft are all linear, when large-angle distortion occurs, the problems of needle roller seizure and shaft burning are easy to occur, the universal joint fails, the durability of the cross shaft is influenced, and the high-service-life convexity cross shaft is provided.

[ summary of the invention ]

The invention aims to solve the problems in the prior art, and provides a high-service-life convexity cross shaft which can effectively avoid the problems of seizure and shaft burning of a roller pin and prolong the service life.

In order to achieve the purpose, the invention provides a high-service-life convexity cross shaft which comprises a central shaft body and four shaft heads, wherein the shaft heads are of two-section structures and comprise linear radial shaft sections connected with the heel part of the central shaft body and arc radial shaft sections connected with the linear radial shaft sections, and the outer diameters of the arc radial shaft sections are gradually reduced from a boundary between the arc radial shaft sections and the linear radial shaft sections to the other ends of the arc radial shaft sections.

Preferably, the arc-line-shaped radial shaft section is an outer convex arc.

Preferably, the end of the shaft head is further provided with an end face chamfer, and the outer diameter of the arc-shaped radial-axial section is gradually reduced from a boundary between the arc-shaped radial-axial section and the straight-shaped radial-axial section to a boundary between the arc-shaped radial-axial section and the end face chamfer.

Preferably, the axial length of the linear radial-axial section is A, the sum of the axial lengths of the arc radial-axial section and the end face chamfer is B, and A is equal to B.

Preferably, the outer diameter of the large-diameter end of the arc-shaped radial shaft section is the same as that of the linear radial shaft section, and the outer diameter of the small-diameter end of the arc-shaped radial shaft section is 0.01-0.04 mm smaller than that of the large-diameter end of the arc-shaped radial shaft section.

The invention has the beneficial effects that: the four shaft heads of the cross shaft are all provided with the linear radial shaft section, the arc radial shaft section and the end face chamfer, the arc radial shaft section is in a trend that an arc line gradually faces downwards from the linear radial shaft section to the end face chamfer, and the end of the arc radial shaft section is close to the end face chamfer. The wear life of a common cross shaft is 80 hours, while the wear life of the cross shaft can reach more than 160 hours and can still reach more than 120 hours in a large-angle state.

The features and advantages of the present invention will be described in detail by embodiments in conjunction with the accompanying drawings.

[ description of the drawings ]

FIG. 1 is a cross-sectional structural schematic view of a long-life convexity cross of the present invention;

fig. 2 is an enlarged schematic view of fig. 1 at I.

[ detailed description ] embodiments

Referring to fig. 1 to 2, the high-life convexity cross shaft of the present invention includes a central shaft body 1 and four shaft heads 2, wherein the shaft heads 2 are of a two-section structure, and include a linear radial shaft section 21 connected to a heel portion of the central shaft body 1 and an arc radial shaft section 22 connected to the linear radial shaft section 21, and from a boundary line between the arc radial shaft section 22 and the linear radial shaft section 21 to the other end of the arc radial shaft section 22, the outer diameter of the arc radial shaft section 22 is gradually reduced, and the arc radial shaft section 22 is an outward convex arc.

Further, the end of the spindle head 2 is further provided with an end face chamfer 23, and the outer diameter of the arc-shaped radial-axial segment 22 is gradually reduced from the boundary between the arc-shaped radial-axial segment 22 and the linear radial-axial segment 21 to the boundary between the arc-shaped radial-axial segment 22 and the end face chamfer 23.

Further, in the present embodiment, the axial length of the linear diametric axis segment 21 is a, the axial length sum of the arc diametric axis segment 22 and the end surface chamfer 23 is B, and a and B are equal. The outer diameter of the large-diameter end of the arc-shaped radial shaft section 22 is the same as that of the linear radial shaft section 21, and the outer diameter of the small-diameter end of the arc-shaped radial shaft section 22 is 0.01-0.04 mm smaller than that of the large-diameter end of the arc-shaped radial shaft section.

The invention relates to a long-service-life convexity cross, wherein a four-shaft head is approximately evenly divided into two sections, the front half section connected with a heel is linear, the rear half section is an arc section, and an arc line is gradually downward from a boundary until the end face is chamfered. The wear life of a common cross shaft is 80 hours, the wear life of the cross shaft can reach over 160 hours, and can still reach over 120 hours under a large-angle state.

The above embodiments are illustrative of the present invention, and are not intended to limit the present invention, and any simple modifications of the present invention are within the scope of the present invention.