| 摘要 |
992,266. Axial-flow blowers. T. HELMBOLD. April 25, 1962 [Sept. 11, 1961], No. 15712/62. Drawings to Specification. Heading F1C. In an axial-flow blower including a casing; radial rotor blades in the casing and a shroud ring surrounding and rotating with the blades, the shroud ring extends in both axial directions for a substantial distance beyond the blades, and the casing has an intake nozzle having at its end adjacent the shroud ring an internal diameter substantially equal to the internal diameter of the adjacent end of the shroud ring. This arrangement reduces backflow at the blade tips and noise. The shroud ring may be frustoconical. The casing may have a recess receiving the ring and labyrinth packings may be arranged in the recess, between the ring and casing. |
