Harmonic Drive LLC | 42 Dunham Ridge, Beverly, MA 01915 | 800-921-3332
Harmonic Drive and Harmonic Planetary are registered trademarks of Harmonic Drive.

Harmonic Drive® precision gearing is known for zero backlash, high torque, compact size, and excellent positional accuracy.
Our motion control products including gearing components, gearheads (also called gear units), and servo actuators exhibit these attributes.


Ultimate design flexibility


Easy to connect to motor/drive


Complete solution, easiest to implement

Harmonic Drive has thee main product categories: Component Sets, Gear Units, and Actuators. Below is a quick explanation of each category. Our simplest products for your motion control use are our complete actuators, while Harmonic Drive® gear component sets offer the ultimate in design flexibility and can be tightly integrated into your machine design.

Component sets offer maximum versatility for the design engineer. A component set is the basic mechanism of a Harmonic Drive® precision gear and can be incorporated into a custom housing, in order to achieve a minimum package size. These high accuracy gearing components are often used as the core building block for custom high performance servo actuators and motion control mechanisms. Customer-supplied servo motors can be easily integrated into the design. Component Set Selector.

Gear Units can be quickly incorporated into your designs to provide precision speed reduction/torque multiplication. They are easily connected between the motor/drive and load. Gear units are housed zero backlash Harmonic Drive® component gears typically combined with a precision cross roller output bearing & flange. Gear Units are a very compact, robust and easy to use gearhead/gearbox solution. Our Simplicity Gear Units are Non-housed component gearing combined with a precision cross roller output bearing. Simplicity Gear Units do not include the housing and output flange, which allows for even tighter integration into your housing or machine structure. Click here to find products

Actuators are an integral package consisting of an encoder, servo motor and precision gearing. Harmonic Drive® rotary actuators deliver both high force and outstanding positional accuracy. Harmonic Drive manufactures our own cross roller bearings, harmonic and planetary gearing, state of the art brushless servo motors and encoders. By having complete control over the design of these critical elements, we have designed the performance matched components needed to develop extremely compact actuators with the highest power density while incorporating unique features such as a hollow shaft. Performance matched precision gearing, motors, and encoders are designed to provide a power dense, cost effective solution.

Click here to see our full product lineup.

Harmonic Drive® strain wave gears are in a class of their own when it comes to motion control and mechanical power transmission. With operating principles and construction that maximize output torque and minimize size and weight, Harmonic Drive® gears offer advantages such as high reduction ratios in a single stage, zero backlash, and high precision that cannot be equaled by conventional gear trains.

Zero Backlash - Cup-style gears operate with zero backlash between mating teeth because of natural gear pre-load and radial tooth movement. The only shaft-to-shaft backlash that exists, originates in the input coupling (oldham coupling) and ranges from 2-36 arc-sec depending on unit size and reduction ratio. This coupling can be eliminated if necessary, resulting in zero backlash for the entire drive.

Excellent Positional Accuracy and Repeatability - Positional accuracy may be minimized within one arc minute and repeatability within a few seconds.

High Torque Capacity - Since power is transmitted through multiple tooth engagement, the gear offers high output torque capacity equal to drives twice its size and three times its weight.

Single-Stage High Reduction Ratio - With only three elements, the single-stage reduction ratios range from 50:1 to 320:1 with the same weight and mechanical dimensions.

In - Line Configuration - The gearing input and output shafts are concentric, allowing machine designers to dramatically reduce the required packaging space compared to other high ratio, high torque drives.

High Torsional Stiffness - The "S" tooth profile greatly improves the torsional stiffness of the gear allowing greater precision and higher servo gains.

Efficiencies - Operating efficiencies of up to 90% can be obtained. Ratings are based on actual shaft-to-shaft tests.

Back Driving - Harmonic Drive® gears are reversible and can be back driven. If necessary, loads can be held in place by braking the Wave Generator when the servo system is not powered.

For more detailed information, visit our technology page.


Contact Us

Submit a Question


Call: 978-532-1800

Hours 8:00am - 5:00pm EST
Monday through Friday