A DEVICE FOR ACCURATE MEASUREMENT OF A ROTOR DIAMETER DURING ERECTION OF HYDROGENERATORS TO REDUCE AN AIR GAP BETWEEN THE ROTATING AND STATIC COMPONENTS

摘要

A device for accurate measurement of the diameter of a rotor (10) in course of site-erection to reduce an air gap (15) between the rotating and static components (10,12) of a hydrogenerator, the rotor having at least a shaft (10) releasably coupled to a spider (11), a rim (23) built around the spider (11) by lamination of tensile sheet steel, and a plurality of poles (13) disposed in the axial direction of the rim (23), the device comprising a shaft assembly (1) detachably attachable to the spider (11); an arm and bush assembly (2) having a substantially close tolerance in respect of the shaft assembly (1) configured to be slideably insertable in the shaft assembly (1); a counter balance weight (7) provided on the opposite side of the arm and bush assembly (2); at least two rope assemblies (3,4) releasably secured on the arm and bush assembly (2) by means of a special screw (5) having oppositely directional threads (RHT, LHT); and a piano wire (8) interposed in the arm (20) of the arm and bush assembly (2) assembled in a cover plate (6).