A housing for retention of the outer race of a bearing of a gas turbine engine includes an arrangement of spring fingers that yields a lightweight housing capable of withstanding very high radial loads combined with very high torsional windup and axial thrust load. Controlled circumferential gaps on both sides of each spring finger limit the deflection and self-arrest the distortion of the housing. The spring fingers define at least one side edge that extends at an angle relative to the axial direction. An axial gap is created on the aft end by a portion of the spring finger beam structure that opposes an axial face of the housing and limits the axial distortion. A radial gap created between interface hardware of the housing and the inner retention housing also acts to retain the spring finger housing under load in a radial direction.

Apparatus for containing a flywheel comprising: a flywheel; a shaft; a bearing arrangement for supporting the shaft; and a housing for housing the flywheel, the shaft and the bearing arrangement; wherein the flywheel is mounted on the shaft, the shaft is mounted to the bearing arrangement, and the bearing arrangement is mounted to the housing; wherein the flywheel has a rim formed by a circumferential face of the flywheel, and a hub formed by a central region of the flywheel, the hub being wider, axially, than the rim such that a circumferential contact surface is formed by the hub that is coaxial with the rim; wherein the housing comprises an annular force transfer region that faces, and is concentric with, the contact surface; and wherein, in use, excessive radial movement of the flywheel results in the contact surface contacting the transfer region.

A housing for retention of the outer race of a bearing of a gas turbine engine includes an arrangement of spring fingers that yields a lightweight housing capable of withstanding very high radial loads combined with very high torsional windup and axial thrust load. Controlled circumferential gaps on both sides of each spring finger limit the deflection and self-arrest the distortion of the housing. The spring fingers define at least one side edge that extends at an angle relative to the axial direction. An axial gap is created on the aft end by a portion of the spring finger beam structure that opposes an axial face of the housing and limits the axial distortion. A radial gap created between interface hardware of the housing and the inner retention housing also acts to retain the spring finger housing under load in a radial direction.