New Direct Drive Permanent Magnet Rotary Servomotors for High Torque Applications

In response to growing demand for more efficient solutions for larger machines, Moog is introducing a new line of flexible high torque, direct drive servomotors. Moog’s large direct drive permanent magnet rotary brushless servomotors are ideal for processes requiring high peak or rated torque.

By eliminating components such as gearboxes and belt drives that are prone to wear, direct drive rotary servomotors improve accuracy and repeatability, enable reduced machine size, offer higher efficiency resulting in energy savings, minimize maintenance costs and downtime, and produce quieter operation.

Moog’s Direct Drive Servomotors are suitable for some of the most demanding applications in the plastic market such as the injection and clamp axes.

  • Injection Axis: Compact design offering high power, high velocity response, and unsurpassed speed control.
  • Clamp Axis: Simplified design without gearbox, allowing higher speed and smoother machine operation.

These servomotors are also used in many metal forming and press applications as well such as the punching axis of the turret punch press.

Benefits of Moog’s Direct Drive Permanent Magnet Rotary Servomotors

Better dynamic performance for more accuracy during high-speed operations
Moog’s Servomotors provide the best available direct drive dynamic response. They combine the highest available peak torque with the lowest moment of inertia resulting in better acceleration and deceleration for improved accuracy during high-speed operation. Compact stator designs reduce overall motor size by at least half the moment of inertia of competitor models. Our unique coil designs produce high peak torque, giving these motors the world’s highest power density per unit volume currently available.

Flexible design for easy machine integration and better performance
Moog will adapt the characteristics and packaging of these motors to provide higher performance and machine design flexibility than previously possible. For instance, the stator design can be adapted to maximize peak or rated torque depending on the application. The hollow shaft can be enlarged to pass cables through or house mechanical components, and every kind of shaft and hollow shaft configuration can be accommodated, including flange, spline, key, and thread. Other options include multiple types of bearing, various feedback devices, and alternative cooling methods.

Moog’s ability to customize both the performance and packaging of these servomotors will enable OEMs to develop higher performance high-power industrial machines with innovative designs where electro-magnetic direct drive servo technology is not yet commonly used.


Daisuke Okada, Manager, Products Engineering & Technology, is responsible for electro-mechanical actuators and direct drive servomotors for Moog in Japan. He has worked for Moog since 1992 as an application and design engineer of hydraulic products as well as a designer of electro-mechanical actuators during his 2-year assignment with Moog in the US.