Abstract: A rotary drive apparatus is provided for connection to a rotary drive string extending downwardly in a well to a rotary downhole pump. Separate axial load bearing and rotary drive spindles are provided and are separately connected to the rotary drive string by readily releasable connectors so as to permit axial adjustment of the rotary drive string while preventing loss of the string into the well in the event of release or slippage of one of the connectors. The design also permits repair or adjustment of the drive apparatus without removal of the rotary drive string from the well.

Abstract: An eccentric shaft particularly for driving a large reciprocating pump, and a method of making the shaft. The shaft includes an elongated cylindrical body, a plurality of small eccentric discs uniformly spaced along the length of the body, and optionally one or more concentric gear flanges, all formed as a single integral forging. Relatively large eccentric discs are shrink-fitted and keyed to the small eccentric discs.