High precision for aerospace show

Having been involved in the aerospace industry ever since, Harmonic Drive has developed a range of gears specifically designed for the needs of the industry and will be exhibiting these at this year’s Farnborough Airshow.

Aircraft rely on precision gearing in order for critical mechanisms to work properly. During flight, the slats and flaps located on the wings are monitored using a position pick-off unit (PPU), which sends position feedback to the flight control system. This ensures that the mechanisms are operated accordingly, allowing aircraft to ascend and descend safely.

Gears for aviation therefore need high positioning accuracy and zero backlash in order for the PPU sensors to have a smooth movement and provide precise feedback. As the tips of aircraft wings are exposed to very cold conditions during flight, it is important that the gears function at low temperature to ensure consistently high quality operation.

Harmonic Drive’s® strain wave gears are favoured by many large aerospace companies due to their excellent positioning accuracy, lightweight design and repeatability. As such, they can be used on a number of aircraft applications such as nose wheel steering, wing flaps and landing gear retractors.

“A particular trend that visitors to the Farnborough Airshow will notice is aircraft manufacturers moving from hydraulic controls for steering, flaps and lifting the wheels, to electromechanical actuation”, explained Graham Mackrell, managing director of Harmonic Drive UK.

“To achieve high accuracy, electrical actuators must have high precision gears, as Harmonic Drive® offers. The gears must also be lightweight, to avoid adding any additional load to the component and the aircraft.

“Through our years of experience in the industry we have developed gears that are perfectly suited to the needs of the aerospace industry, including high torque capacity and high torsional stiffness. For example, all our gears for the aerospace industry are made from stainless steel and are completely traceable, which is essential to comply with safety regulations in the aerospace industry.”