摘要 |
<p>Regenerative hydraulic power transmission for subsurface pumps, including a power source, a variable flow rate hydraulic pump, means to reverse flow through the hydraulic pump responsive to change in direction of the subsurface pump stroke, and an inertial assist for the power source which gathers energy from the downstroke of the subsurface pump and utilizes the gathered energy to power the upstroke of the subsurface pump. The transmission can vary upstroke speed apart from downstroke speed, pump stroke length and dwell time of change in stroke direction.</p> |