| 摘要 |
<p>A high pressure liquid nozzle housing encloses a self-rotating speed-controlled nozzle. A cylindrical sleeve in the housing forms an inwardly facing friction surface engageable by a nozzle-driven friction generating speed control mechanism to provide increasing retarding force on the nozzle as nozzle speed increases for controlling maximum nozzle rotational speed. The speed control mechanism includes a radially expandable helical coil spring rotatable with the nozzle with its windings at low nozzle speeds slightly spaced from the sleeve. An input end of the coil spring is driven by the nozzle structure in a direction tending to unwind the spring and increase its outer diameter in response to rotation of the nozzle. An output end of the coil spring rotatably drives a cluster of centrifugal weights which are spring biased away from the sleeve and which at low nozzle rotation speeds also remain spaced from the sleeve. At higher speeds of nozzle rotation the weights move outwardly and frictionally engage the sleeve and provide a drag on the output end of the spring to aid in unwinding the spring, increasing its diameter and moving it with progressively increasing force into friction creating engagement with the sleeve to provide progressively increased retarding force against nozzle rotation as nozzle speed increases. The weights and spring retarding forces combine, but the spring retarding force is several times the retarding at the weights when an equilibrium between retarding forces and opposing jet stream nozzle reaction is reached at maximum nozzle speed.</p> |
