| 摘要 |
<p>The present invention relates to a pair of co-operating screw rotors (1, 2), where each rotor (1, 2) has helically extending lobes (6, 7) and intermediate grooves, through which the rotors intermesh. One rotor is a male rotor (1) where each lobe (6) in a section perpendicular to the rotor axes (OM, OF) has a leading lobe flank (14) and a trailing lobe flank (15), both being substantially convex. The other rotor is a female rotor (2) where each lobe (7) in the same section has a leading (16) and a trailing (17) lobe flank, both being substantially concave. Each lobe of the male and female rotor has an asymmetric profile. According to the invention at least one (14, 15) of the flanks of a male rotor lobe has a circular arc segment (11, 18), which at least at each end of the segment has the shape of a circular arc. Each circular arc shaped portion of the segment has equal radius (R1; R2) and coinciding centre of curvature (A1M, A2M). This radius (R1; R2) deviates from the difference between the external radius (RM) and the pitch radius (RMP) of the male rotor. The female rotor lobe flank (17, 16) co-operating with said one flank has a flank segment (10, 19) co-operating with said flank segment (11, 18) of the male rotor lobe. The invention also relates to a screw rotor intended to be one of the rotors in such a pair and to a rotary screw machine provided with such pair of screw rotors.</p> |
