Harmonic Drive to showcase new actuators

The centrepiece of Harmonic Drive's exhibition will be the company's new range of compact and hollow shaft servo actuators - The LynxDrive, the CHA-14 and CHA-17 lightweight hollow shaft models. Each actuator in the LynxDrive range features a synchronous servo motor, feedback sensors and a high precision Harmonic Drive HFUC Series Gear Unit, lowering both energy consumption and running costs.

Graham Mackrell, managing director of Harmonic Drive, explains: "When we developed the LynxDrive range, we focused our efforts on creating the most compact design possible, without compromising on quality."

Its compact build makes the LynxDrive range suitable for applications in the broadcast, military, aerospace, and oil and gas industries, enhancing its use for precise positioning actuation for high performance machinery.

The CHA-series, meanwhile, combines the high accuracy and reliability common to all Harmonic Drive products, with a central hollow shaft. The CHA's hollow shaft feature enables original equipment manufacturers (OEMs) to pass power supply cables, shafts or laser beams directly through the servo actuator, considerably reducing development costs and assembly time.

Graham Mackrell says: "The key advantage of our gearing systems is the zero backlash function. The problem with competing technologies is that even a very small amount of backlash on the gear can create significant errors at the output. Our strain wave gearing, which is very different from other gear systems, consists of only three basic elements. Our Wave Generator uses a ball bearing deformed into an ellipse, which creates a wave as it turns.

"The Flexspline, which fits over the Wave Generator is flexible and takes on the elliptical shape as it moves. The third element of the gear, the Circular Spline is a rigid ring with internally cut teeth. Crucially there are two teeth more than on the Flexspline.

"If you look at the Flexspline as an unconstrained cylinder it appears perfectly cylindrical. But if you look at the cross section of the major axis of the ellipse you see a coning angle, which allows the preload of the gear. So, as you assemble the elements, the teeth engage. Instead of rolling, the teeth withdraw, advance and re-engage a single tooth at a time for each revolution of the gear. Typically the Circular Spline is rigidly mounted and attached to a servo motor - providing genuine zero backlash for the life of the unit."

Also included in Harmonic Drive's exhibition will be the versatile HFUC series component sets, the new, smaller FHA Mini range of actuators, and the new lightweight Torque Drive series.

The Engineering Design Show will be held at Coventry's Ricoh Arena from the October 22 to 23, and is expected to attract up to 4000 British design engineers. To learn more about Harmonic Drive's new range of servo actuators, visit the company on stand number G50, or go to www.harmonicdrive.co.uk.