Direct Drive Motors: How They Work and Best Applications

direct drive motorsDirect drive motors have existed for some time, but they've recently been gaining popularity among OEMs and system integrators due to the numerous design advantages they have over traditional motor systems.

But how are direct drive motors different? What kinds of applications are they best for?

How Direct Drive Motors Work

Direct drive motors are any motor that directly drives a load without mechanical power-transmission components such as gears, pulleys or chains. In most instances however, the term 'direct drive motor' refers to brushless permanent-magnet motors.

Direct drive motors produce motion when electrical power is supplied to the stator's windings, which react with magnets on the rotor. The two forces attract and repel each other to create a rapid, frictionless motion.

These motors are typically small, frameless and have low energy consumption, making them easy to integrate in most applications.

Best Applications for Direct Drive Motors

Direct drive motors typically have a very high torque to inertia ratio. This means that small amounts of torque are needed to accelerate the motor. Consequently, direct drive motors are best for applications that require high speed and high acceleration in a small space.

As mentioned, direct drive motors are often frameless. This gives them advantageous thermal geometry, as well as large airgaps to resist shock and dirt. In other words, they're built to survive rugged industrial environments.

Direct drive motors eliminate the need for transmissions and gearboxes, which means there's no mechanical friction or inertia produced. In this way, direct drive motors are significantly more energy efficient than their mechanical counterparts, requiring far less power for the same power and torque.

Direct drive motors are commonly used in the medical, aerospace, defense and industrial sectors. One of the most frequent applications is for use in gimbals in antennas and satellites, due to the reliability and dynamic motion created by direct drive engines.

OEMs and integrators often cite the high cost of direct drive motors as their major disadvantage, but when you factor in long-term costs such as ongoing maintenance, efficiency, design simplification and other benefits, direct drive motors often end up being cheaper.

Direct drive motors are gaining popularity in the motion control industry due to their many design advantages. To see some of the most advanced products on the market, browse our directory of direct drive motor suppliers.