Automatic doors: speed reducers for motion control and precision

The use and application of automatic doors is increasingly common beyond shopping malls, hospitals and large office spaces. The complex systems for door automation require great control and precision, which is why the selection of the speed reducer should involve a very precise study. In this article we will delve into the operators and actuators in charge of the optimal operation of an automatic door, as well as the role of speed reducers or actuators for driving the doors’ system and motion control. Let’s begin. 

First, we will go over the selection criteria for speed reducers in automatic door operators, where the design of the speed reducer and safety features will guide this process.


How to select the perfect speed reducer for automatic doors

The design and specifications of the speed reducer is key to generate the perfect motion in automatic doors and accomplish the objectives set for this type of electromechanical project. Regardless of whether we are referring to hinged doors, swinging doors, sliding doors or telescopic doors, in all cases we will have to pay attention to the following selection criteria:


  • Output torque

At the technical level, the main aspect to consider when selecting a speed reducer for operators should be the continuous rated torque. Don’t overlook this detail!

The gear motor should be prepared for the weight of the door, keeping in mind the amount of duty cycles per time unit the automation will be subjected to. It is very important for your speed reducer supplier to conduct extensive service life tests as well as onsite tests that guarantee the proper operation of the system for its commercialisation.


  • Motion safety

For this type of project, security is paramount, which demands the speed reducers to be equipped with systems that guarantee the total safety of users. One such example would be a fast opening system with a controlled stop system at the end of the run. This will achieve an effective, completely controlled opening.

Safety regulations for automatic door operators depends on each country, in Spain, in the UNE EN 16.005 standard. Your speed reducer supplier should be familiar with this standard and ensure compliance with all the requirements described.


 swing door operator
Example of operator for swinging doors | Source:


  • Polarity reversal

When referring to polarity reversal in a motor or gear motor we are referring to the ability of spinning the direct current motor in either direction – clockwise or counter-clockwise. Except for automatic revolving doors, reversing the polarity is necessary for most opening systems.


You may be interested in: “How to select the best electric motor in small drives


What is the most suitable gear motor for automatic door operators?

In these electromechanical engineering projects it is essential to consider how exactly the actuation will take place. And with this in mind, the selection of the most suitable gear motor will depend on the speed of the motion, the torque and the space available to accommodate the actuator.

For this application, worm gear motors –with a 90 degree output shaft- or planetary speed reducers are commonly used; this is due to their high torque delivered in limited spaces.


CLR, the safety of the perfect motion

CLR, Compañia Levantina de Reductores is experienced in the execution of electromechanical projects for operator and automatic door manufacturers. We have, for instance, developed and designed speed reducers for automated hinged doors in leading companies of the sector, having achieved great results that have boosted our clients’ confidence.

Our engineering department has a significant know-how in all types of electromechanical solutions for various industrial sectors. This allows us to offer innovative solutions and satisfy the needs of our clients, overcoming any engineering obstacle or challenge.

You may have arrived at this article because you need to add a speed reducer or actuation solution to your project. Here at CLR we want to assist you – we recommend that you download our eBook “Gear motors: Choosing the best one for each project”. In it you will find criteria to choose the gear motor that best suits your needs.


Gear Motors Guide

1 thought on “Automatic doors: speed reducers for motion control and precision”

  1. Automatic doors can be scary. I love how this article talks about speed reducer for those doors. Having motion safety is huge for children and the elderly.

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