Technical conditions of automobile universal joint cross shaft

The design selection technology and the domestic and foreign standard practical manual are excerpted from the technical conditions of the car universal joint cross shaft.

1. Assembly

1. The safety factor Ns of static torsional strength must be greater than 2.5

2. Torsional fatigue life: the number of cycles shall not be less than the fifth power of 2*10

3. The wear life shall not be less than 60h

4. Radial clearance of needle roller bearing assembly (request chart from China Coupling Network)

5. The assembly length tolerance zone is h11 specified in GB/T1801-1999

6. After the assembly is assembled, the bearing should rotate flexibly

7. The circlip, pressure plate, bolts and other assembly accessories brought by the customer should be complete and intact.

8. Appearance quality: The working surface of the assembly parts should not have defects such as bumps, scratches, black spots, etc., and should be clear of burrs and sharp edges; non-processing performance must be shot blasted to show the true color of the metal.

9. After the assembly is assembled, add No. 2 general-purpose lithium-based grease for automobiles in accordance with GB/T5671-1995.

2. Cross axis

1. Materials and heat treatment

1) The material is made of 20CrMnTi, 20Cr and other alloy structural steels specified in GB/T3077-1999.

2) The cross shaft must adopt the heat treatment method of carburizing and quenching. The depth of the effective hardened layer of the journal carburizing and quenching is based on the size of the cross shaft journal (relevant charts from China Coupling Network)

3) The hardness of the journal surface should be 58~64HRC, and the difference between the hardness values ​​of all measuring points on the journal surface of the same cross shaft should not exceed 2HRC. When using 20CrMnTi material, the core hardness should be 33~48HRC, and when using other materials, the core hardness should be 25-45HRC.