Patent ID: 6328136
Filing Date: 2001-12-11
Classification: B66B,H02K

Abstract:
A drive machine for elevators, comprising:an electric motor including a rotatable drive sheave over which a main cable for hanging an elevator cage is wound,a stationary shaft for supporting rotation of said drive sheave and bearing a load applied to said drive sheave from said main cable,a field magnet attached to said drive sheave and comprising at least one pair of magnetic poles,an armature attached to said stationary shaft, facing said field magnet and constituting part of said motor,detected portions comprising at least one pair of convex or concave portions on or in the surface of said drive sheave at a pitch corresponding to the positions of magnetic poles of said field magnet for indicating the position of the magnetic poles, anda position detector disposed facing said detected portions for detecting the position of said drive sheave by detecting whether said detected portion is opposite said position detector and, thereby, the position of the magnetic poles of said field magnet that rotate together with said drive sheave.