Recent developments in the design of gearless machines forelevators

摘要

The authors describe the benefits that have been obtained from areview of traditional gearless elevator machines. Known as gearlessmachines because of the absence of intermediate gearing, they comprise amotor-traditional DC-driving an integrally mounted rope sheave and arecharacterised by operating at low speeds-rarely more than 300 rpm-andhigh torques. They require very large diameter shafts in order tosupport the elevator system and consequently are generally of massiveproportions relative to their output power. Larger sizes need to bemounted on a substantial bedplate, and their weight and size oftencreates handling problems during installation in the confined space andaccess to many hotels and office buildings in which they are mostcommonly used. The review of such a machine has resulted in a modularform being evolved. In this arrangement, the rope sheave is supportedwithin a separate cradle, to which the driving motor is flange mounted