Abstract: The present invention relates to a flywheel apparatus for energy storage and recovery including a housing within which there is a chamber in which a flywheel on a shaft rotates. The chamber is evacuated to at or near vacuum pressure, so that air resistance-related energy losses of the flywheel as it rotates are reduced. Maintaining near-vacuum pressure within the chamber requires an effective seal between the housing and the shaft. The effective seal must be maintained despite any relative movement (in particular translational movement) of the flywheel and the housing. To this end, the shaft is mounted via a bearing arrangement on a carrier on which is also mounted a sealing arrangement. The carrier is mounted on the housing such that the carrier, the bearing arrangement and the sealing arrangement move substantially together relative to the housing.

Abstract: The present invention relates to a flywheel apparatus for energy storage and recovery including a housing within which there is a chamber in which a flywheel on a shaft rotates. The chamber is evacuated to at or near vacuum pressure, so that air resistance-related energy losses of the flywheel as it rotates are reduced. Maintaining near-vacuum pressure within the chamber requires an effective seal between the housing and the shaft. The effective seal must be maintained despite any relative movement (in particular translational movement) of the flywheel and the housing. To this end, the shaft is mounted via a bearing arrangement on a carrier on which is also mounted a sealing arrangement. The carrier is mounted on the housing such that the carrier, the bearing arrangement and the sealing arrangement move substantially together relative to the housing.