Abstract: An annular rotor for a flywheel, the rotor comprising a tow comprising a matrix of fibres wound about an axis and arranged in layers comprising a gap between adjacent tow windings, wherein the winding angle between a normal to the axis and the tow is less than 3.5° and the matrix further comprises magnetic particles of a size less than the critical flaw size of the tow.

Abstract: A method of making a magnetically loaded pre-impregnated tape uses a drum 1 that is heated and which is associated with a heated bath 2 containing a thermoplastic resin solution. A fiber tape material 4 is fed onto the drum 1 and, just prior to the fiber tape material meeting the periphery of the drum, the fiber tape material 4 is impregnated with an isotropic magnetic particle material 6 to form a pre-impregnated tape 8. The pre-impregnated tape is fed to a heating station where it is bonded with a thermoplastic resin impregnated fiber tow to produce a magnetically loaded composite tape. The heating station includes a rotatably driven heated mandrel (20) having a magnetic field (41, 42) embedded therein to provide the pre-impregnated tape (8) with a desired magnetic configuration.

Abstract: A flywheel for kinetic energy storage and its construction using composite materials. The present invention provides a flywheel assembly having a longitudinal axis and comprising an annular rotor and a rotor support for coupling the rotor to an axial shaft, wherein the rotor comprises fibers in a matrix material, and a ring comprising fibers in a matrix material is mounted on the outer circumference of the rotor support and the rotor is mounted on the outer circumference of the ring, the rotor, rotor support and ring each having longitudinal axes which are coincident with the longitudinal axis of the assembly. The presence of the intermediate ring formed of a composite material assists in the fabrication of the assembly and increases its durability by providing a suitable interface between the rotor and a rotor support.

Abstract: A flywheel used for kinetic energy storage and the construction of the flywheel using composite materials. The present invention provides a rotor support for coupling an annular flywheel rotor to a shaft for rotation with the shaft, the support comprising a body having a longitudinal axis about which it rotates in the finished flywheel assembly, wherein the body comprises a stack of sheets of a composite material including fibers, the stack includes at least two unidirectional sheets, each having substantially all of their fibers extending in the same direction, and the fibers of one of the unidirectional sheets are orientated at a different angle to the longitudinal axis of the body to the fibers in another unidirectional sheet. The body includes at least one side layer of woven fabric provided over a side of the stack of sheets. The rotor support configuration of the present invention provides a stiff construction.

Abstract: A flywheel used for kinetic energy storage and the construction of the flywheel using composite materials. The present invention provides a rotor support for coupling an annular flywheel rotor to a shaft for rotation with the shaft, the support comprising a body having a longitudinal axis about which it rotates in the finished flywheel assembly, wherein the body comprises a stack of sheets of a composite material including fibres, the stack includes at least two unidirectional sheets, each having substantially all of their fibres extending in the same direction, and the fibres of one of the unidirectional sheets are orientated at a different angle to the longitudinal axis of the body to the fibres in another unidirectional sheet. The body includes at least one side layer of woven fabric provided over a side of the stack of sheets. The rotor support configuration of the present invention provides a stiff construction.