Motion control solutions

Motion control solutions

Motion control solutions

Keywords: Aircraft components, Control equipment, Actuators

Harmonic Drive used the recent Farnborough International Airshow as a platform to promote its range of motion control solutions that have been specifically designed and developed for a wide range of aircraft applications where high precision and reliability are critical. Just as importantly, the latest Harmonic Drive precision gears and actuators claim high levels of accuracy, high torque, high power density and a long operating life, all in lightweight and compact dimensions.

Harmonic Drive precision gears have been designed to achieve a mean time between failures in aircraft applications of more than 500,000h, with an extremely low failure probability. Furthermore, Harmonic Drive gears and actuators are said to provide positional accuracy of less than one minute of arc and a repeatability of just a few seconds of arc, making them suitable for use in aircraft applications requiring exceptionally high positional and tracking accuracy.

Harmonic Drive technology is used in a wide range of aircraft applications including military fighter jets for active pilot inceptors providing force-feedback to the operator, and commercial aircraft such as the Airbus A380.

On show were Harmonic Drive's range of HFUC component sets, which claim a combination of low weight, compact dimensions, high torque capacity, exceptional repeatability and positioning accuracy, and can be used in a wide range of operating temperatures, making them ideal for use in various aircraft applications including cargo handing and in-flight systems.

The new HFUC component sets incorporate a shortened Flexspline, resulting in a significant reduction of the axial length. Furthermore, the new component sets feature high performance IH tooth profiles to provide increased torque capacity in comparison to standard gears that incorporate traditional involute gear tooth profiles.

The HFUC range is available in 15 gear sizes from 8 to 100, with a choice of gear reduction ratios, from 30:1 to 160:1.

In addition, the HFUC component sets feature the optimised design of Flexspline, Circular Spline teeth and Wave Generator bearing, to eliminate completely the effects of backlash, provide high torsional stiffness and offer a range of output torque capacities from just 0.9 to 3,550Nm.

The company also be demonstrated its FHA series miniature hollow-shaft servo actuators, which are believed to be the world's smallest servo actuators. Measuring just 50mm³ in size and weighing only 0.4Kg, these ultra compact actuators are capable of delivering 1.8Nm of torque from an integrated AC motor, gearbox and encoder, while featuring a choice of gear reduction ratios, including a 30:1 gear ration – the first of its kind to be achieved with hollow shaft servo actuators.

Specially developed for use in demanding aircraft applications where highly accurate motion control and high torque capacity are key, or where operating space or weight are restricted, the innovative FHA series features advanced Harmonic Drive technology to eliminate the effects of backlash. Additionally, the integrated AC servo motor provides exceptionally smooth torque curves, with output speeds of between 60 and 200rpm.

By integrating a motor, gearbox, output bearing and encoder into a single, compact and lightweight unit, the FHA actuators allow aircraft design and manufacturing engineers to reduce dramatically both the time and cost associated with system design, specification and construction. Perhaps as importantly, the new servo actuators allow considerable improvements to be made in system performance, precision and reliability, while minimising overall size and weight.

Details available from: Harmonic Drive UK Ltd Tel: +44 (0) 1785 245190; Fax: +44 (0)1785 240126; web site: www.harmonicdrive.co.uk