Abstract: A rotor stage of a gas turbine engine includes a platform from which rotor blades extend. The platform is provided with a circumferentially extending damper ring, the damper ring having an engagement surface that engages with the platform. The damper ring provides damping through slip between the engagement surface and the platform. The damper ring has a hoop stress that results in a load being provided to the platform from the engagement surface. The load can be optimized in order to provide improved damping.

Abstract: A rotor stage (100) of a gas turbine engine (10) comprises a platform (120) from which rotor blades extend. The platform is provided with a circumferentially extending damper ring (200), the damper ring having an engagement surface (210) that engages with a platform engagement surface (110) of the platform (120). The platform engagement surface (110) and the damper engagement surface (210) can move relative to each other in the radial direction. In use, the damper engagement surface (210) moves less in the radial direction than the platform engagement surface (110) in response to diametral mode excitation. This causes friction between the two surfaces, thereby dissipating energy and damping the excitation.

Abstract: A rotor stage (100) of a gas turbine engine (10) comprises a platform (120) from which rotor blades extend. The platform is provided with a circumferentially extending damper ring (200), the damper ring having an engagement surface (210) that engages with the platform. The damper ring has a cross-sectional shape perpendicular to the circumferential direction that has a depth (a) in the radial direction, and a neutral bending axis (250) that is spaced (b) from the engagement surface by more than half of the depth. Increasing the spacing between the engagement surface and the neutral bending axis increases the amount of slip at the interface between the damper ring and the platform, thereby increasing the amount of frictional damping.