Moog Components Group Offers Fractional Horsepower Brushless DC Motors

Moog Components Group specializes in the design and manufacturing of optical components, fiber optics and electronic systems for a wide variety of applications. Formerly called Poly-Scientific, this division is known for motion technology such as high performance motors, slip rings, fiber optic rotary joints, and actuators as well as electronic systems. Since being acquired by Moog in 2003, this division has continued to grow and integrate with the industrial organization to provide a variety of unique solutions for customers. As part of our newsletter theme on customized high performance solutions, this article focuses on offerings of fractional horsepower brushless motors.

The Silencer™ line of fractional horsepower motors from the Moog Components Group provides solutions for a wide variety of applications ranging from medical equipment to textiles (see below). This line consists of six frame sizes (BN12, 17, 23, 28, 34 and 42) with compact aluminum housings in outside diameters from 30.5 mm (1.2 in.) to 106 mm. (4.2 in.) Each frame size is available in four different lengths with a variety of windings. Continuous torques range from 13 mNM (2.4 oz-in) to 3670 mNm (519 oz-in), speeds up to 16,000 rpm, rated power ranges from 17 to 874 watts. These motors have been designed for low terminal voltages (mostly in range 12 - 50V) allowing for a power supply from a low voltage source or a battery.

The standard construction of these motors involves a permanent magnet rotor on the inside that is surrounded by the wound stator with a three-phase winding. Due to the utilization of bonded neodynium magnets, these motors provide high power density in a very compact package. A high number of poles (8) and skewing of magnet poles reduces torque ripple (cogging). Built-in “Hall effect switches” provide feedback information to the drive to electronically commutate the motor for velocity control.

The Silencer™ series of brushless motors from Moog Components Group provide smooth, efficient and reliable operation. They are ideal for a wide range of industrial applications where a precise speed control, quiet operation and long life are a requirement.

Motor Versions

  • High Speed Motors: The four pole motors offer relatively high speed (up to 36,000 rpm) in the same package size. They are ideal for applications demanding high speed levels, such as centrifuges, blowers and medical drills.
  • High Performance Motors: When maximum performance and minimum size are important, this option that utilizes high energy sintered Neo magnets, offers an increased (almost 2 times) torque in the same frame size.
  • Motors with Integral Drive Electronics: Complex wiring is eliminated by integrating the drive electronics directly onto the motor, coupled with the internal connections of the “Hall effect switches.” This ensures system integration is substantially simplified and offers compact packaging to minimize the space required.

Typical Applications

  • Medical Equipment
  • Automatic door and window openers
  • Textile industry
  • Packaging and printing products
  • Labeling equipment
  • Food processing machinery
  • Pumps and ventilators
  • Semiconductor handling

Additional Offerings

  • Electronic Drives: The Silencer™ Series electronic drives are matched for optimum performance with BN motors. The drives are low profile packages designed for ease of mounting in a small envelope, requiring minimal space in a cabinet. Features include:

Efficient PWM speed control

  • Planetary Gearheads: Used by applications demanding low speeds. Features include:
  • Encoders: The motor rear side is matched for fixing standard optical encoders from HP (resolutions up to 1024 CPR). Improved feedback allows more precise velocity control at lower motor speeds.

Customized Solutions Example

Moog Components Group also offers customized products designed to meet OEM’s special system requirements. An example of a unique small-package solution we developed is a special motor for Gallus Ferd. Rüesch AG, the label printer manufacturer based in Switzerland. The customer needed motor assemblies (motor types BN23 and BN34), gearheads, and encoders for auxiliary driving axes. The important requirement was a „ready to mount“ solution without the need for additional harnessing. Our engineering team quickly created a new design and the solution was delivered to the customer on time and to the unique specification.


Vladimir Benada is an Applications Engineer for Moog in Germany, providing technical support for Moog Components Group (MCG) products. He designed servomotors for over 10 years and worked previously for LPPI (a former distributor of MCG in Europe) focusing on supporting motors and slip ring products. He has a Masters degree in Power Electrical and Electronic Engineering from the Technical University of Brno.