Linear motor elevator device with a null-flux position adjustment

Abstract

A linear motor elevator includes: a multitude of primary side coils mounted on the hoist way along the whole hoist path, and vertical columns of permanent magnets constituting the secondary side magnets mounted on the elevator car. The polarity of the permanent magnets alternate both horizontally across the columns and vertically along respective columns. When the elevator car is displaced horizontally in a direction perpendicular to the hoisting direction of the elevator car, a circulating current producing a magnetic flux that counterbalances the variation of the flux caused by the displacement flows through each primary side coils opposing the permanent magnets on the elevator car. Thus, the position of the elevator car within the hoist way is automatically adjusted in accordance with the null-flux method.