The ABAG (Advanced Bearings And Gears) project supported the SAGE2 project aims to demonstrate technologies for a Geared CROR (Counter-Rotating Open-Rotor) engine concept. The gearbox system requirements, transferring power from the low-pressure turbine to the propellers, lead to the need of new, advanced technologies for critical components in particular bearings and their integration with the surrounding components (e.g. gears).

The task and technical objectives are in particular:

• Advanced planet bearing design including static and dynamic analysis considering the foreseen working conditions.
• Definition of new technologies to meet the bearing life and reliability requirement under the expected operation conditions and technology development steps.
• Demonstration through experimental test of bearing life and wear resistance (low contamination sensitivity) improvement of new technologies.
• Demonstration through experimental tests for the applicability of the new technologies to gear materials and geometry of optimum bearing integration.

The activity was managed with a Phase & Gate approach and will include detailed technical/program documentation, including planning, drawings, design report, risk analysis, test plan and test requirements, test results and test analysis reports.