单螺杆钻具马达的普通外摆线线型分析

本文采用逆解法对i=N/(N+1)普通外摆线线型进行理论分析,指出该线型的骨线共轭副满足理论密封性,但因其等距曲线存在着严重打扣现象而不能用于实际线型设计。另外,由公式推导表明,普通外摆线线型的马达最小长度L_(min)与线型有关,且为头数N的函数。文末给出了五条结论。

Study on Cmmon Eqicyolid Contour-pattern of Downhole Drilling Motors

In this installment the authors present a study on the i=N/(N+1)common epicycloid contour-pattern in light of the method of reversal and point out that even though the conjugate curves of such contour-pattern meet the requirements of leak tightness,they are not available for the actual design due to the severe interference of the isometric curves. The derivation of formula shows that the minimal length(L_(min)) of a motor with common epicycloid contourpattern is relevant to the contour-pattern and is a function of the lobe number(N). At the end of this installment the authors reason out five conclusions.