Abstract: Experiments based on theories pertaining to elasticity, finite deformation and fluid sealing have been conducted to provide data for designing pistons and nylon rings. Radial displacement of surface of nylon ring, stress distribution in the whole piston and contact stress distribution on the surface of piston are determined by strain gage measurement, photoelastic method and pressure compensation method. Modification tests of the construction and the property of materials used for the nylon rings have also been carried out. From the results of experiment, it has been proved that the home-made triangular or rectangular nylon rings offer good protection to the heel of the piston. Adequate regulation of the tolerance between the nylon ring and the cylinder may reduce the surface contacting stress of the piston, and the property of materials used for making the nylon rings may be ameliorated by heat treatment.

摘要： 本文应用弹性理论、有限变形理论和流体密封理论对钻井泥浆泵活塞及尼龙环进行了实验研究。分别用电测法、光弹性法和平衡压力法测定了尼龙环表面径向位移、活塞全域应力状态和活塞表面接触应力分布。同时也对活塞尼龙环的结构和材料性能进行了改进试验。试验结果表明,国内批量生产的三角尼龙环活塞和平尼龙环活塞均具有护根作用;适当地放大尼龙环与缸套之间的间隙,严格控制尺寸公差,对减小活塞表面接触应力是有益的;对尼龙环材料(Mc尼龙)可进行热处理改性。为活塞及护根环的设计提供了依据。