【正文】 當(dāng)夏季溫度較高時(shí)，若供油量過多，軸承上不但不能冷卻和潤(rùn)滑，反而因嚴(yán)重?cái)嚢璎F(xiàn)象而使軸承升溫；若供油量過少，軸承潤(rùn)滑不夠，溫度也會(huì)上升，所以供油量與噴油的位置決定了軸承的合理潤(rùn)滑，以確保軸承的熱穩(wěn)定性。改造前須檢查主軸箱前主軸孔的尺寸是否可改造成。s normal work.5 increase the headstock spindle speedThe replacement lathe driving pulley (belt pulley), increases the spindle speed by original n max=600r/min to n max=900r/min. Meets the requirements which the spindle speed enhances.Supposition rightful owner drive wheel outer diameter D1=120㎜, namely D1/D2= n1/n2≥120/D2=600/900≥D2=180㎜, increases the driving pulley outer diameter to 180㎜.6 conclusionsAfter the reequipping C620 lathe, its front bearing structure is reasonable, the adjustment is convenient, makes the main axle system39。s 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 mon difference in the scope, before and, main bearing hole aperture processing to 。 Sped up bearing39。s rotation precision, when assembly uses “the directional assembly” the principle carries on, guaranteed that the rotation precision in design requirements39。同時(shí)軸承間隙調(diào)整困難，間隙過大，加工精度達(dá)不要求。100的要求(要求留有磨削余量).,、外圈的調(diào)整墊片(要求墊片厚度留有修磨量).完畢,再對(duì)主軸軸頸部分進(jìn)行磨削加工,達(dá)到主軸應(yīng)有的各項(xiàng)要求。3mm中心孔，然后安排在精度較高的車床上，用雙頂針的方法，進(jìn)行車削加工，按軸承內(nèi)孔基孔制的要求，將主軸軸頸部分加工成錐度為1:12(錐度4o4639。在這種狀態(tài)下顯然加快了軸承的自然磨損，從而縮短了主軸的使用壽命，導(dǎo)致主軸回轉(zhuǎn)精度的逐漸降低，很大程度影響了加工精度和生產(chǎn)效益。s regulation means and front bearing39。s 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 highspeed cutting39。s method, carries on