MOTORS: Gear-less vs. Geared

The electric motor, the work horse of modern industry.  Since the Industrial Revolution motors of one form or another have shaped our lives. In the beginning we would first would power up an electric motor and simply see how fast it could spin.  Then we would attach the motor to pulleys and gears load them up until they burned up. We later realized that if you increase voltage and motor windings you would increase the power of the motor.  Eventually we learned more about electricity we could adjust the frequency or aptitudes making our motors perform better, thus the invention of “The Control”.

Today electric motors are a huge industry in and of themselves they have become very job specific and the control today is just if not more important than the motor it runs. I’m not trying to give you a history lesson on motors and controls but rather look at how they affect our industry in power operated doors.   

Most power sliding doors use a gear motor which consists of an electric motor attached to a set of gears to provide the needed torque to move a large sliding door.
This gets the job done, the door moves. 

However having gears attached to a motor adds to the moving parts and to the maintenance. Now you have grease fitting, chains and with chains more grease and grime.  Because of this particular system now when the door looses power you have to have a mechanical disconnect to open the door in an emergency situation again adding to the moving parts of the door.

Sounds complicated doesn’t it. Great for the maintenance man they will be busy.
The question is how can we simplify this system?

Well why not take the gears out and change the greasy chain to a titanium reinforced cog belt that is moved by a cog pulley attached to the motor shaft. Then use a Gear-less Motor or Induction AC motor aka” the squirrel cage” motor that freewheels when the power is off. 

Is this a new motor? No an inventor by the name of Nikola Tesla designed this motor in 1882. It is one the most common motors used today in fact. It’s the same motor that is used with gears.

Why do others use gears? It’s all about torque. The gears give them a mechanical advantage to overcome the weight of the door and add torque to the system to move the door. OK how can we take away the gears and still move a large door?

First EMS doors are light and strong due to their design, 10# foam without any wood or add structural frame to weigh down the door.

Second our rail and rollers eliminate friction and rolling resistance with sealed bearings in our rollers. Once the door is out of the seal depressions built into our rail the door moves easily.

Third and most importantly our engineers have developed a Control that dynamically adjusts the current to the motor increasing the torque to move the doors without added gears. The very nature of the motor allows the motor to freewheel when powered off.
     
The benefits:

·    The motor naturally freewheeling eliminates add safety features like the mechanical disconnect.

·    Without all those extra moving parts, the gears, the mechanical release and the grease fittings we have eliminated a lot of maintenance. Good right?

·    Replacing the chain with a dry cog belt giving us a clean greaseless way of moving our door. No need for a cover for the chain we don’t have one to collect dirt and grime.

·    Again less maintenance and cost.

To recap EMS-USA has provided the only to date in the USA “Gearless Motor Drive” to our sliding door line. Providing a simple, clean, and well engineered product to our customers.


By:  Jesse O’Neil
        EMS-USA