Patent ID: 7637357

Claim:
An elevator apparatus, comprising: a traction machine having a traction machine body and a traction sheave rotated by the traction machine body; a driven sheave disposed apart from the traction sheave; a main rope looped around the traction sheave and the driven sheave; a car and a counterweight suspended by the main rope; a driving-side speed detecting portion for detecting rotational speed of the traction sheave; a driven-side speed detecting portion for detecting rotational speed of the driven sheave; and an operation control device having a determination portion for calculating speed difference between the rotational speeds of the traction sheave and the driven sheave based on information from the driving-side speed detecting portion and the driven-side speed detecting portion, and comparing the speed difference calculated with a fixed reference value, set in advance, to determine presence or absence of an abnormality in an elevator, and a control portion for controlling operation of the elevator based on information from the determination portion.