Flywheel

A flywheel comprising

• a plurality of discs arranged in a stack, including at least first and second end discs at either end of the stack, each of the plurality of discs including a plurality of disc apertures therethrough,
• first and second plate members disposed at opposing ends of the stack, one or both of the first and second plate members including a plurality of plate apertures therethrough for alignment with a corresponding series of disc apertures through the stack, in which one or both of the plate members includes one or more recesses which are disposed on a disc-facing side thereof and positioned adjacent to one or more of the plurality of plate apertures, and
• connection means for clamping the first and second plate members together about the stack of discs, the connection means extending through each of the plurality of disc apertures, in which a spacer or space-filling means is provided between the or each connection means and the respective disc apertures for supporting the connection means, the spacer or space-filling means extending from a position within the stack into the one or more recesses of at least one of the plate members,
• in which:
• a minimum width of each plate aperture is less than a width of each disc aperture, or
• at least some of the disc apertures are provided in a linear series, the or each plate aperture meets a respective end of the linear series, and the disc apertures in the linear series are wider than the or each plate aperture where the or each plate aperture meets the respective end of the linear series.

A flywheel comprising,

• a plurality of discs arranged in a stack, including at least first and second end discs at either end of the stack, each of the plurality of discs including a plurality of disc apertures therethrough,
• first and second plate members disposed at opposing ends of the stack, one or both of the first and second plate members including a plurality of plate apertures therethrough for alignment with a corresponding series of disc apertures through the stack, in which one or both of the plate members includes one or more recesses which are disposed on a disc-facing side thereof and the one or more recesses include a disc-facing surface positioned adjacent to one or more of the plurality of plate apertures, and
• connection means for clamping the first and second plate members together about the stack of discs, the connection means extending through each of the plurality of disc apertures, in which a spacer or space-filling means is provided along a length of the or each connection means within the stack between the or each connection means and the respective series of disc apertures for supporting an external sidewall of the connection means, the spacer or space-filling means extending from a position within the stack into the one or more recesses of at least one of the plate members,
• in which the spacer or space-filling means is in the form of a sleeve having a bore fitted around the connection means, and in which the sleeve extends through the stack into the one or more recesses of both of the plate members.