GB611258A - Improvements in or relating to rotary compressors or engines - Google Patents

Abstract

611,258. Rotary compressors or engines. AKTIEBOLAGET LJUNGSTROMS ANGTURBIN, and BOESTAD, G. K. W. April 25, 1946, No. 12608. [A Specification was laid open to inspection under Sect. 91 of the Acts, Oct. 28, 1946.] [Class 110 (ii)] The compressor (or engine) is of the type described in Specification 464,476 and has a male rotor 26 having helical lands and grooves, the major portions of which lie outside the pitch circle and a female rotor 28 having lands and grooves, the major portions of which lie within the pitch circle, the casing having passages such as 16 each containing a throat and widening towards the casing inlet or outlet port. The mean line 46 of the throat and passage is inclined away from the plane 48 which passes through the axes of the rotors. The velocity of fluid passing through the throat is approximately equal to the fluid velocity in the addendum region of the male rotor. The inlet or outlet passage, such as 34, is formed partly in the end casing 16, and partly in the main casing 12. In Fig. 4, the outlet port in the outlet end wall is shown by a line a<1> ... i<1> and in Fig. 6 the portion in the side wall is shown by a line k<1> ... o<1>, the front providing for both axial and radial communication with the working chambers. To increase the pressure ratio, the outlet port is made small, but for lowpressure discharge the axial side-wall portion may be made longer.