Abstract: A friction wheel door drive for a sliding door for lifts consisting of at least one rectilinearly or curvilinearly moved door leaf (1), which is suspended of guide rollers (3) and is guided at a guide (2) is presented. At least one of the guide rollers (3) is formed as a motor roller (3') moving the door leaf and in the form of an outside rotor motor. The motor may be either a direct current motor with permanent magnets in the outside rotor and electronic commutation or a polyphase induction motor with a laminated outside rotor having a short-circuited winding and a laminated inner stator with a polyphase alternating current winding. Force transmission between the motor roller (3') and a running roller (3") may be provided by a transmission (18), between motor roller (3') and running roller (3") is possible.

Abstract: An apparatus and a method for moving an elevator door utilizes computed travel curves to control a door drive. The actual speed and position of the door are inputs to a travel curve computer in which travel curve algorithms are stored. Constants used in the algorithms are freely selectable and are communicated to the computer through a terminal connected to the computer. The computer generates target values a regulator which controls a power unit connected to the door drive motor for the opening, closing and reversing operations of the door.