| 摘要 |
<p>To control the flow of fluid from a positive displacement pump to a consumer line, a rotating shutter periodically opens return flow nozzles which permit the pressure-free return of the pumped fluid to a fluid reservoir. In order to provide hydraulic balancing of the forces on the shutter, the return flow nozzles are disposed symmetrically with respect to the axis of the rotating shutter. Pressure peaks which occur when the return flow nozzles are closed cause undesirable noise generation and these pressure peaks are reduced by the disposition of separate check valves associated with each of the symmetric flow conduits. The use of separate check valves reduces the length of the fluid column which must be accelerated upon nozzle closure. To reduce the opening stroke of the check valve, the edge of the valve seat meanders thereby extending its effective length. Axial play of the rotating shutter is controlled by the disposition of a spring loaded glide block.</p> |
