The invisible door opener for Schindler from Maxon Motors

Louise Smyth

The lift manufacturer Schindler transports more than a billion people every day. Its lifts operate in skyscrapers as well as apartment buildings, where they travel up and down all day long. Who actually stops to think about the little motors that open and close the doors? 

Lifts are among the things in our daily lives that we take for granted. We press the button, the cab arrives, we enter and are taken to the desired floor quickly, safely and reliably. Yet hidden from the passengers’ eyes, there is quite a lot of technology involved in the liftshaft, in the motor chamber, in the control box and in the cab itself. A motor installed in the cab is responsible for opening and closing not only the door of the cabin, but also the door to the respective floor. The demands on this motor are high: it has to be small yet powerful, energy-saving, reliable, and, most importantly, intelligent.

Together with Schindler, maxon motor has developed a drive system that moves the doors and meets the listed requirements. The Maxon Door Drive is available in two power levels. The more powerful version uses a belt drive and is able to move doors of up to 400kg. The smaller, newer version is a direct drive. This saves space and is suitable for doors up to 120kg.

Intelligent controller

This system solution consists of a brushless DC motor with a diameter of 90mm and a MILE encoder integrated directly on the print. It is combined with a customer-specific positioning controller based on the EPOS2 series. Encased in a housing, the Door Drive can be mounted directly to the lift cab. And this is where its real work starts. There are many different types of lifts, with differently sized cabs, different materials and, depending on the country, different safety standards. After a calibration procedure, the Door Drive’s controller detects the size and weight of the doors, autonomously calculates the optimal parameters, and corrects them if necessary. This greatly simplifies the lift technician’s work. In just a few steps, the Door Drive configuration is complete, and the drive is ready for use.

Valuable data

The advantage of the flat motor’s narrow design is that the cab can be made bigger. The drive also saves energy. Nevertheless, it delivers sufficient torque to smoothly move the doors. Last but not least, its integrated controller is intelligent. In continuous operation, it collects valuable data that the technicians can access at any time. This means that besides doing its main job, the drive also functions as an assistant behind the scenes.

The complete drive solution for lift doors consists of a brushless flat motor (90mm diameter), an integrated MILE encoder, and a customer-specific positioning controller based on the EPOS 2 series.

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