Machining Method of Bearing Mandrel with Keyway at Both Ends

Abstract

The invention discloses a method for machining a bearing mandrel provided with key grooves in the two ends. The method comprises the following steps of conducting quenching treatment on the mandrel; conducting rough grinding of the large excircles, grinding of the two end faces and rough grinding of the small excircles on the mandrel obtained after quenching; conducting fine grinding of the large excircles, fine grinding of the small excircles, grinding of channels and ultra-precision channel machining with respect to rough grinding of the small excircles; obtaining a large excircle step through grinding after conducting rough grinding of the small excircles and before conducting fine grinding of the large excircles, in another word, grinding the surfaces of the excircles of the ends where the key grooves are formed and obtaining the step, wherein the length of the step is slightly longer than that of the corresponding key groove, and the external diameter of the step is smaller than the dimension of each excircle after fine grinding of the large excircles is conducted. By the adoption of the method, large excircle roundness of the bearing mandrel provided with the key grooves in the two ends can reach approximately one micrometer, and under the circumstance of existing machining capability, precision of the bearing mandrel can be remarkably improved.

Description

technical field [0001] The invention belongs to the field of mechanical processing, in particular to a processing method for a bearing mandrel with key grooves at both ends. Background technique [0002] Such as figure 1 As shown, the schematic diagram of the parts of the bearing mandrel with key grooves at both ends, the mandrel is characterized by a keyway at one end of the large outer circle, a small outer circle at the other end, and a keyway at the end of the small outer circle far away from the large outer circle. Keyway, and the directions of the two keyways are at an angle of 180 degrees to each other. The existing processing technology is as follows: blank processing - quenching - rough grinding of the large outer circle - grinding double end faces - rough grinding of the small outer circle - fine grinding of the large outer circle Round—fine grinding small outer circle—grinding double grooves—superfine double grooves—general inspection and storage. There is a key...

AI Technical Summary

Problems solved by technology

[0002] like figure 1 As shown, the schematic diagram of the parts of the bearing mandrel with key grooves at both ends, the mandrel is characterized by a keyway at one end of the large outer circle, a small outer circle at the other end, and a keyway at the end of the small outer circle far away from the large outer circle. Keyway, and the directions of the two keyways are at an angle of 180 degrees to each other. The existing processing technology is as follows: blank processing - quenching - rough grinding of the large outer circle - grinding double end faces - rough grinding of the small outer circle - fine grinding of the large outer circle Round—fine grinding small outer circle—grinding double grooves—superfine double grooves—general inspection and storage. There is a keyway on the circle, so the surface of the large outer circle with the keyway is not a complete circle, and there is an opening. The opening of the keyway will scratch the grinding wheel and the guide wheel during the through-grinding, causing the mandrel to bounce on the support during the through-grinding process, causing the mandrel The roundness of the outer circle is seriously out of tolerance, basically above 8μm (the process requirement is within 2μm). During the processing, the mandrel bounced and the grinding wheel was damaged. The large outer circle of the shaft is used as the reference. Due to the large roundness of the large outer circle, serious out-of-tolerance problems such as the roundness of the groove and the contour of the groove line in the subsequent grinding and ultra-finishing processes are caused.

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