Axialverdichter,Geblaese oder Ventilator mit verminderter Geraeuscherzeugung

摘要

1,019,158. Axial-flow compressors, blowers and fans. J. JENIE, J. NEMEC and Z. MORAVEC, May 20, 1964 [May 21, 1963], No. 20781/64. Heading F1C. Noise in an axial-flow compressor, blower or fan is reduced by arranging that #/#o is greater than 0À65, where To is the circumferential pitch of the blades of either the stator 1, Fig. 2, or the rotor 2, measured at the tip diameter D 2 , Fig. 3, and # is determined graphically as follows. A point B on the trailing edge 3 of a stator blade at a diameter D is projected at b on to the conical surface of revolution described by the leading edge 4 of a rotor blade, intersecting this surface at a point B1. The locus of all such points B1, from the root diameter D 1 to the tip diameter D 2 , when further projected parallel to the axis O of rotation on to a plane at right angles to this axis forms a trace 31 on that plane of the trailing edge 3. The leading edge 4 is similarly projected on to this plane to form a trace 41. If these traces 31 and 41 are rotated about the axis O until they have a common point E on the root diameter D 1 , they subtend at the tip diameter D 2 the required value #. A similar construction can be applied in the case in which the stator blades follow the rotor blades instead of preceding them. The optimum value of S is Z r /Z s , where Z r is the number of rotor blades and Z s is the number of stator blades. Preferably, Z r /Z s = 1/k, i/2, where i is an integral positive odd number and k is an integral positive number or Z r /Z s = 1/k (i-2/3) or 1/k (i-1/3), where i and k are integral positive numbers.