| 摘要 |
<p>An elongated borehole logging instrument includes a permanent magnet linear reciprocating motor. The motor powers a sliding sleeve which has attached to its outer perimeter a series of reversible vanes. The vanes engage the mud cake or the borehole wall and thus generate a force opposite to the direction of the vane slant. The motor has a stationary electromagnetic field comprised of a plurality of coils connected to the control electronics. The floating outer sleeve has permanent magnets all oriented in the same direction. As the coils are pulsed alternatingly, the magnets are either repulsed or attracted to thus generate a reciprocating motion which transferred to the vanes moves the tool up or down, depending upon the position of the reversing actuator.</p> |
