| 摘要 |
<p>A device for generating pressure pulses in flowing fluid includes a valve having a stem movable linearly relative to a passageway. The valve is configured to vary restriction to flow through the passageway in response to changes in relative position between the stem and the passageway. The device also includes a rotatable member in operable communication with the valve such that rotation of the rotatable member causes the stem to move, and a motion translation arrangement that is in operable communication with the rotatable member and the stem such that the stem linearly reciprocates in response to the rotatable member rotating in a single direction of rotation.</p> |
