用于磨削抽油泵镀铬柱塞的螺纹弹性定位轴

Thread positioning device for use in grinding chrome-plating plunger on oil well pumps

针对在抽油泵镀铬柱塞的磨削加工中采用螺纹堵头存在重复定位精度低等问题，将弹簧夹头式定心夹紧机构的工作原理与螺纹定位方法相结合，设计制造了镀铬柱塞内螺纹自动定心装置——螺纹弹性定位轴。这种装置可以自动定。心张紧，消除了螺纹间隙，杜塞粗磨、精磨的重复定位精度偏差可控制在0．015mm以内；还消除了内螺纹表面脏清及端面残铬、污渍对定位精度的影响。与使用螺纹堵头相比，用螺纹弹性定位轴磨削加工柱塞可使粗磨余量减少15％－20％，镀铝量减少20％－30％，相应的精磨余量也减少30％左右。

In the light of the problems of low acculacy and lepeated positioning in grinding chrome-plating pltinger on oil wellpumps by using the thread plug, a thread automatic centering device, the elastic thread positioning shaft, is developed.By using this device, the thread clearance can be eliminated with automatic centering and tensioning, the deviation of thegrinding accuracy can he conbolled within 0.015mm, and the influence of di1t and remained chlnme on thlead surfaceand ends on the positioning accuracy can be eliminated. By using the elastic thread positioning shaft for ghnding plungersinstead of the thread plug, the rough grmnding allowance can be decreased by 15% ~ 20%, the amount of chrome platedcan be decreased by 20% ~ 30%, and the finish grinding allowance can be decreased by about 30%.