| 摘要 |
<p>A drive means for downhole use comprises an input shaft and an output shaft, the input shaft being coupled to a means of rotation, the input shaft and the output shaft being torsionally coupled, the output shaft being coupled to the rotor of the progressive cavity pump, the input shaft lies in a first axis and the output shaft lies in a second axis, the second axis being parallel to the first axis but spaced from it so that the output shaft rotates about its axis while describing a circular path.</p> |
