Improvements in or relating to screw compressors

Abstract

Abstract 1,237,333. Screw compressors. GUTEHOFFNUNGSHUTTE STERKRADE A. G. Oct.15, 1969 [Oct. 24, 1968], No.50619/69. Heading F1F. To regulate the output of a screw compressor having main and auxiliary intermeshing screwed rotors 2, 3, Figs. 1, 4 driven by a worm 4 and worm wheel 5, an axially adjustable control slide 7 has a plurality of transverse bores 17 communicating with the compressor working chamber through bores 18 and with an elongate feed opening 19<SP>1</SP> from a passage 19 supplied with lubricating oil under pressure. As the control slide 7 is adjusted rightwardly on rotation of a screwed shaft 9 either by a motor (not shown) or by means of a handwheel 10, the rightmost bore 17<SP>1</SP> is moved out of communication with the opening 19<SP>1</SP> whilst another bore 17<SP>11</SP> is brought into communication with the opening 19<SP>1</SP> so that the zone of the rotors receiving the oil is only insignificantly displaced with decrease in compressor output. As shown, the opening 19<SP>1</SP> co-operates with five bores at any one time, the number may however be different and there may be more than one opening 19<SP>1</SP> with associated bores. In an alternative embodiment, lubricant may be admitted to an annular chamber 21, Fig. 5, in a stationary piston 20 which is supplied through bores 22, 23 by a lubricating pump (not shown). On adjustment of a control slide 7<SP>1</SP>, bores 18 are brought into and out of register with the chamber 21 in a similar manner to the bores 17 with respect to the opening 19<SP>1</SP>.

Inventors

No inventors recorded.

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