Liebherr-Aerospace introduces innovative lubricant

As part of a research and technology program, Liebherr-Aerospace Lindenberg GmbH (Germany) and dedicated lubricant manufacturers have during the last four years jointly developed a lubrication fluid that meets the challenging temperature conditions in aviation. One of the objectives was to achieve a constant friction ratio over a wide temperature range. This is required to ensure long term stability and performance of no-back brakes contained in actuators during the entire service life cycle of an aircraft.

In the automotive industry, so called “automatic transmission fluids” are used for a similar reason relating to friction. However, the products currently available on the market for this purpose are not suitable for the low temperatures required in aviation due to their high viscosity. Therefore, the team developed a new formulation of these lubricants that provides the desired friction coefficient stability in a low-viscosity and therefore low-temperature compatible version.

Synthetic hydraulic oils that are currently used as lubricants for aviation actuators and gearboxes change their viscosity depending on the fluid temperature. Compared to these lubricants, the new one not only demonstrated the desired friction coefficient consistency in an endurance test but also improved low-temperature efficiency and corrosion protection. It therefore represents a further building block in continuous product improvement of aviation products and demonstrates the relevance of lubricants to be considered as a “wet design element” as part of aircraft engineering and certification.