GB967091A - Improvements in or relating to three-stage radial-flow compressors - Google Patents

Abstract

967,091. Centrifugal compressors. BORSIG A.G. March 13, 1962 [April 14, 1961], No. 9546/62. Heading F1C. In a three-stage radial-flow compressor for gas or air provided with double intermediate cooling and a gearing arrangement having a large central gear-wheel adapted to co-operate with three pinion shafts distributed over the periphery thereof, each of the stages has associated therewith an individual pinion shaft having a compressor rotor mounted overhung on an extension of the shaft and driven at a most favourable speed of the stage concerned, and the compressor housings for the three rotors are cast or flanged on the gearing housing. Three stages 17, 18, 19, Fig. 1, of a compressor are respectively driven at their most favourable speed through pinions 2, 3, 4, of suitable diameters, meshing with a large central gearwheel 1 driven by an electric motor 5 through an intermediate shaft 6 and two couplings 7, 8. The pinions 2, 3, 4 are preferably arranged around the gear-wheel 1 as shown in Fig. 2 with the intermediate pinion 3 above or below the gear-wheel 1. Further, the stages 17, 18, 19 are preferably arranged as shown, but they may be arranged all on one side of the gear-wheel 1 or, any stage may be placed opposite the two others. Interstage coolers 14 and 16 are provided. In an alternative embodiment (not shown), the compressor stages may instead be driven by a steam turbine which may be cast or flanged to the gearing housing and is connected either directly, or through an intermediate shaft and two couplings; to one of the pinion shafts. The pinion shaft chosen is the one associated with the compressor stage whose speed corresponds best with that of the turbine, thereby avoiding the use of additional transmission gearing. It is stated to be known to have a four-stage compressor in which a large central gear-wheel driven by an electric motor drives four pinions each of a size adapted to the rotor of its respective stage. Each rotor disc is driven by a pinion shaft constructed as a torsion rod and is supported at its other side by a pin fixed on or integral with the compressor housing and extending into a central blind bore in the rotor disc. Specification 714,765 is referred to.