附录 C620 lathe main axle structure transformation design Ren Fu jun huang ru lin wang qun Abstract: The C620 lathe main axle front bearing, changes presents D3182120 rolling bearing structure by the original sliding bearing, its principal advantage is the rigidity is good, the rotational speed is high, and revolves, the rotation precision to be high steadily, the radial direction beats small, the thermostability to be good as well as the assembly technology capability is good. Enhances the product advantageously the working accuracy and the productivity, lengthens equipments service life, reduces the maintenance cost, raises the equipment utilization rate. Key word: Main axle, sliding bearing, rolling bearing, lubrication1 transformation reason lthe C620 lathe main axle front bearing is uses the sliding bearing structure, the spindle speed defined that in n max= in the 600r/min scope, this kind of bearing in high-speed cuttings situation, the bearing is extremely easy to give off heat, the temperature reaches as high as 70 oC; Sped up bearings natural attrition obviously under this condition, thus reduced main axles service life, causes the main axle rotation precision gradual reduction, the very great degree has affected the working accuracy and the production benefit.Because sliding bearings material uses ZQSn6-6-3 generally, the service is complex, the axis blows grinds requests high, the technical difficulty is big, the maintenance cost is also high. Simultaneously the bearing clearance adjustment difficulty, the gap is oversized, the working accuracy reaches does not request; The gap is too small, will appear gives off heat even forms the stuffy vehicle phenomenon. is solves the above malpractice, the sliding bearing changes rolling bearings structure before the original main axle, simultaneously enhances the spindle speed to n max=900r/min, made the obsolete equipment to enhance the rigidity and the rotation precision, raised equipments use factor.2 transformation process in does not affect the main axle other shafting components structure under the premise to open the original front bearing, and carries on the remanufacture processing to the original front bearing hole and the main axle. Like Figure 1, shown in Figure 2, and designs the axis front bearing which manufacture as shown in Figure 3. Its structure by the main axle, the end cover, the clamp, the shell, the bearing, the adjusting washer, the bolt, the stopping nut and so on is composed. This structure selected the D3182120 double row centripetal cylindrical roller bearing to transform the C620 lathe main axle front bearing structure, its principal advantage was: The rigidity is good, the rotational speed is high, and revolves steadily, the rotation precision is high, the radial direction beat is small, the thermostability is good as well as assembly technology capability good and so on characteristics. Just before the transformation, must inspect the headstock, the main axle hole size whether can transform. main axle holeFigure 1 after transformation front bearing holeFigure 2 after transformation main axleFigure 3 after transformation main axle front bearing1 main axle 2 end cover 3.Clamp 4 shell 5.bearing 6,7.Gasket 8.bolt 9. stopping nutMeets the bearing outer diameter D=150mm size requirement, and inspects the main axle axle diameter whether can transform bearing inside diameter d=100mm the size, when the two meet the above requirement, then begins to arrange the transformation work.2.1 headstock main axle front bearing hole transformationIn order to guarantee lathe main axle hole and rolling bearing outer rings grade of fit, when processing should follow the basic shaft system the principle, and arranges on the clang bed to carry on the clang hole processing to the headstock front bearing hole. This work must be very careful, achieves the craft precision for the guarantee, truncates when the processing must the bearing hole carry on take the original main axle around as the datum adjusts, around definite main axle bearing hole proper alignment common difference in the 0.015mm scope, before and, main bearing hole aperture processing to 1500-0.022mm; Roundness tolerance.First should inspect the original main axle slipper the journal section size, because the remainder are not many, must grasp the machining allowance. Before the processing, prepares two 5 morse tapers beforehand the craft center end cover (e.g. Figure 4), inlays separately again the end cover before the main axle in the rear end awl hole, and grinds on carefully the end cover the 3mm center bore, then the arrangement on the precision high lathe, with the double thimbles method, carries on the lathe work, according to the bearing in the hole basic hole systems request, processes the main axle journal part the taper is 1: 12