Hobbing cutter outside bearing position

Abstract

The invention discloses a hobbing cutter outside a bearing position. The total lengths of H2 sizes of all standard blocks 1 are the same as those of H4 sizes of all standard blocks 2, but the H2 sizesand the H4 sizes are progressively increased or progressively decreased according to the half of the inner diameter of a bearing; the bearing has the standard size, so that the size of the bearing position rolled out can reach the standard size; and through the rolling, the hardness of the surface of a spindle can be increased, and the bearing is prevented from slipping.

Description

technical field [0001] The invention belongs to mechanical cutters, in particular to a hob cutter. Background technique [0002] Hobs are divided into knurling knives and hobbing knives. Knurling knives roll out straight lines or nets on the surface of mechanical parts, while hobbing knives are tools for gear processing, and hobs outside the bearing are knurling knives without lines. , in the processing of shaft parts, the tolerance requirements of the bearing position are relatively strict, generally between +0.01mm and +0.03mm. For example, if the supporting bearing is 6209, then the bearing position size of the shaft is 45.01mm To 45.03mm, that is, the bearing can only be an interference fit. The service life of the bearing is not only closely related to the physical and chemical properties of the bearing itself, but also related to the interference fit of the shaft. If the size of the interference fit is too large, the balls of the bearing Or the roller is squeezed by t...

AI Technical Summary

Problems solved by technology

[0002] Hobs are divided into knurling knives and hobbing knives. Knurling knives roll out straight lines or nets on the surface of mechanical parts, while hobbing knives are tools for gear processing, and hobs outside the bearing are knurling knives without lines. , in the processing of shaft parts, the tolerance requirements of the bearing position are relatively strict, generally between +0.01mm and +0.03mm. For example, if the supporting bearing is 6209, then the bearing position size of the shaft is 45.01mm To 45.03mm, that is, the bearing can only be an interference fit. The service life of the bearing is not only closely related to the physical and chemical properties of the bearing itself, but also related to the interference fit of the shaft. If the size of the interference fit is too large, the balls of the bearing Or the roller is squeezed by the outer ring and the inner ring, resulting in increased friction and increased bearing wear. The size of the interference fit is too small or there is no interference fit. The inner ring and bearing position of the bearing are easy to loosen, and may shake in severe cases. The looseness of the inner ring of the bearing and the main shaft is aggravated, resulting in relative rotation between the inner ring and the bearing position. During the rotation process between the inner ring and the bearing position, the friction between the inner ring and the bearing position will cause the main shaft bearing position to become smaller. The ring becomes larger and cannot be used in the end. Moreover, after the spindle bearing is worn out, the spindle itself is relatively large or the center hole of the spindle is damaged, then subsequent maintenance is more difficult. Strictly speaking, the spindle size is + 0.015mm, the interference fit is ideal, but the processing accuracy of ordinary lathes and the measurement accuracy of measuring tools are difficult to guarantee the ideal state of the processing size, even for CNC machine tools, after a period of use, the general processing accuracy is 0.01 mm to 0.02mm. In addition, the factory machining accuracy of ordinary chucks is only about 0.07mm. Therefore, if it is an ordinary lathe, the lathe needs to be measured many times, and the tool needs to be fed multiple times. The efficiency of machining the bearing position is relatively Low, even if it is a CNC machine tool, the final feed size is very small, the feed amount is too large, it is difficult to control the size, and in the process of feed, the workpiece and the tool tip produce friction, because the hardness of the tool head material is greater than that of the workpiece material The hardness of the workpiece can be seen as the cutting tool biting the workpiece material. In this process, the surface hardness of the workpiece material is reduced.

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