Double split blade lock ring

#A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The fan section typically includes a plurality of fan blades that are supported within slots formed in a hub or rotating disk. The fan blades retained within the slots by a split ring. The split ring must be of sufficient stiffness to provide the desired retention. Disadvantageously, as fan sections grow larger, the stiffness of the retaining ring is also required to increase. Increases in required retaining ring stiffness can result in assembly difficulties.

#Accordingly, it is desirable to develop a fan blade retention configuration that eases assembly while maintaining required retention strength.

#A rotor assembly according to an exemplary embodiment of this disclosure, among other possible things includes a plurality of blades including a root portion and an airfoil portion. A rotor includes a plurality of slots for receiving the root portion of the plurality of blades. The rotor includes an annular groove. A first retaining ring is received within the annular groove. A second retaining ring is received within the annular groove against the first retaining ring.

#FIG. 1 is a schematic view of an example gas turbine engine.

#FIG. 2 is a schematic view of an example rotor hub.

#FIG. 3a is a plan view of one example retaining ring.

#FIG. 1 schematically illustrates an example gas turbine engine 20 that includes a fan section 22, a compressor section 24, a combustor section 26 and a turbine section 28. Alternative engines might include an augmenter section (not shown) among other systems or features. The fan section 22 drives air along a bypass flow path B while the compressor section 24 draws air in along a core flow path C where air is compressed and communicated to a combustor section 26. In the combustor section 26, air is mixed with fuel and ignited to generate a high pressure exhaust gas stream that expands through the turbine section 28 where energy is extracted and utilized to drive the fan section 22 and the compressor section 24.

#Although the disclosed non-limiting embodiment depicts a turbofan gas turbine engine, it should be understood that the concepts described herein are not limited to use with turbofans as the teachings may be applied to other types of turbine engines; for example a turbine engine including a three-spool architecture in which three spools concentrically rotate about a common axis and where a low spool enables a low pressure turbine to drive a fan via a gearbox, an intermediate spool that enables an intermediate pressure turbine to drive a first compressor of the compressor section, and a high spool that enables a high pressure turbine to drive a high pressure compressor of the compressor section.

#The example engine 20 generally includes a low speed spool 30 and a high speed spool 32 mounted for rotation about an engine central longitudinal axis A relative to an engine static structure 36 via several bearing systems 38. It should be understood that various bearing systems 38 at various locations may alternatively or additionally be provided.