1. The surface roughness of the shaft shall be in accordance with the provisions of gb1801. The surface of the shaft in contact with the oil seal shall be ground to a surface roughness of ra0.2-0.63um and Rmax = 0.8-2.5um.

2. The diameter tolerance of the shaft shall not exceed H11 according to gb1801.

3. The chamfering width shall be in accordance with the requirements of gb13871-92.

4. Surface hardness: carbon steel and alloy steel are suitable for the shaft, and the recommended hardness is above hrc45. When the medium is dirty and there are pollutants from outside or the linear speed of the shaft is ≥ 12m / s, the surface hardness of the shaft should be hrc50-60, and the depth of quenching layer should be ≥ 0.3mm.

5. The shaft chamfering shall be 30 degrees (maximum), and there shall be no burr, sharp angle and spiral machining marks on the chamfering surface. The roughness of chamfering surface shall be RA ≤ 3.2um, and the carbonized layer of heat treatment must be polished and removed.

Special attention:

(1) The surface roughness of the shaft is too high, and the oil seal lip is easy to wear and leak oil.

(2) The burr, sharp angle and spiral machining mark at the chamfering are easy to scratch the oil seal lip, resulting in the initial seal failure of the oil seal.

(3) Avoid or reduce the shaft damage, sand hole, installation eccentricity and radial runout and other defects.