A method of manufacturing a flywheel comprising: forming a first hollow cylinder from glass fibre composite with magnetic particles dispersed through at least part of the cylinder; curing said first cylinder in a first curing step; forming a second hollow cylinder from carbon fibre composite; and curing said second hollow cylinder in a second curing step.

A method of manufacturing a flywheel comprising: forming a first hollow cylinder from glass fibre composite with magnetic particles dispersed through at least part of the cylinder; curing said first cylinder in a first curing step; forming a second hollow cylinder from carbon fibre composite; and curing said second hollow cylinder in a second curing step.

A flywheel formed of a composite material having fibers, oriented substantially in a circumferential direction around the flywheel, embedded in a matrix material. The flywheel having an inner surface, an outer surface, and a thickness therebetween and defining an axis of rotation. A plurality of load masses are distributed circumferentially on the inner surface at a longitudinal segment along the axis. A rotation of the flywheel about the axis with a rotational velocity generating hoop stress in the fibers in the circumferential direction and through-thickness stress is generated in the matrix material in a radial direction. Each load mass produces a force on the inner surface operative to reduce the maximum through-thickness stress in the matrix material as the flywheel rotates about the axis. The rotational velocity otherwise sufficient to produce structural failure of the matrix material produces structural failure of the fibers and not the matrix material.

A flywheel formed of a composite material having fibers, oriented substantially in a circumferential direction around the flywheel, embedded in a matrix material. The flywheel having an inner surface, an outer surface, and a thickness therebetween and defining an axis of rotation. A plurality of load masses are distributed circumferentially on the inner surface at a longitudinal segment along the axis. A rotation of the flywheel about the axis with a rotational velocity generating hoop stress in the fibers in the circumferential direction and through-thickness stress is generated in the matrix material in a radial direction. Each load mass produces a force on the inner surface operative to reduce the maximum through-thickness stress in the matrix material as the flywheel rotates about the axis. The rotational velocity otherwise sufficient to produce structural failure of the matrix material produces structural failure of the fibers and not the matrix material.

Flywheel system properties are enhanced with rim designs that control stress at operational rotational velocities. The tensile strength of fiber-resin composites can be aligned with radial forces to improve radial stress loading. Loops with composite casings can be arranged around the flywheel circumference with a majority of the fibers being aligned in the radial direction. The loops can enclose masses that contribute to energy storage in the flywheel system. Masses can be arranged around the hub circumference with a hoop wound composite casing enclosing the masses and hub. The masses subjected to radial forces are radially displaced with increasing rotational velocity and can provide compressive force to the fiber-resin composite to contribute to maintaining composite integrity. With the alignment of fibers in hoop or radial directions, higher loading permits increase rotational velocities, which can significantly add to the amount of energy stored or produced with the flywheel.

An example flywheel energy storage device includes a fiber-resin composite shell having an elliptical ovoid shape. The example device also includes an axially oriented internal compressive support between the axial walls of the shell. The example device also includes an inner boss plate and an outer boss plate on each side of the shell. The example device also includes a plurality of radially oriented, fiber-resin composite helical wraps forming the shell and coupling the shell to the inner and outer boss plates for co-rotation and torque transfer. The example device also includes boss plate attachments on internal boss plate supports to mount the shell for co-rotation and torque transfer via resin bonding, friction, and compression between the inner and outer boss plates.

An example flywheel energy storage device includes a fiber-resin composite shell having an elliptical ovoid shape. The example device also includes an axially oriented internal compressive support between the axial walls of the shell. The example device also includes an inner boss plate and an outer boss plate on each side of the shell. The example device also includes a plurality of radially oriented, fiber-resin composite helical wraps forming the shell and coupling the shell to the inner and outer boss plates for co-rotation and torque transfer. The example device also includes boss plate attachments on internal boss plate supports to mount the shell for co-rotation and torque transfer via resin bonding, friction, and compression between the inner and outer boss plates.

Rotor hubs described herein include a frustoconical body having a base, a frustum, and a longitudinal axis extending therebetween, and a plurality of elongated protrusions spaced about a circumference of the base and extending from the base parallel to the longitudinal axis.

Composite rotors provided herein include a rotor body extending along a longitudinal axis including a first component extending longitudinally along at least a portion of the rotor body and a second component extending longitudinally along at least a portion of the rotor body, at least a portion of the second component disposed concentrically around the first component, wherein the first component and the second component together define an internal region, wherein a radial thickness of the first component and a radial thickness of the second component vary along the longitudinal axis. The composite rotor also includes at least one magnet disposed on an inner surface of at least one of the first component or the second component within the internal region.

Apparatuses, systems and methods are described for a flywheel system incorporating a rotor made from a high-strength material in an open-core flywheel architecture with a high-temperature superconductive (HTS) bearing technology to achieve the desired high energy density in the flywheel energy storage devices, to obtain superior results and performance, and that eliminates the material growth-matching problem and obviates radial growth and bending mode issues that otherwise occur at various high frequencies and speeds.