Patent ID: 9200629
Filing Date: 2015-12-01
Classification: F04B,G01D

Abstract:
1. A system for determining position of a polished rod of a reciprocating rod pumping system having a prime mover driving reciprocating motion of the polished rod using one or more components transferring prime mover motion to the polished rod, the reciprocating motion of the polished rod comprising a stroke cycle, the system comprising: a proximity sensor and a proximity sensor target, one of the proximity sensor and the proximity sensor target being mountable on a selected point on a reciprocally moving component of the reciprocating rod pumping system and the other of the proximity sensor and the proximity sensor target being mountable on a corresponding selected fixed location, the proximity sensor being configured to transmit a detection signal on detection of the proximity sensor target, the reciprocally moving component comprising the polished rod or one of the one or more components; and a receiving system configured to receive a plurality of detection signals form the proximity sensor, the plurality of detection signals comprising a detection signal resulting from detection of the proximity sensor target during a downstroke portion of the stroke cycle and a detection signal resulting from detection of the proximity sensor target during an upstroke portion of the stroke cycle, the receiving system further being configured to determine a time of each of the plurality of detection signals, and to determine from said times a position of said polished rod for at least one point of the stroke cycle.