Abstract: A unitary, wide rim of fiber composite material for use in conjunction with flywheels for inertial energy storage apparatus, the rim being fabricated to minimize radial stresses and equalize hoop stresses ordinarily produced at high speed rotation of the flywheel. Novel fabrication techniques include varying the density of the rim as a function of radius by means of ballasting; and using a combination of layers of fibers having different modulus of elasticity. By utilizing the aforesaid novel fabrication techniques, a preferred embodiment of a unitary, thick flywheel rim achieves radial stress reduction to trivial levels and hoop stress equalization sufficient to permit extremely efficient energy storage as a function of flywheel weight.

Abstract: A unitary hub and method of fabricating such a hub for use in conjunction with flywheels for inertial energy storage apparatus, the hub having a double convex domed configuration cut into double spider leg shape upon which a flywheel rim, such as one comprising fiber composite material, may be wound directly. The hub further comprises two cylindrical bars affixed to the center of the outer convex surfaces of the oppositely facing domes to form axles of the hub, and two similar bars which are affixed to the center of the inner concave oppositely facing surfaces of the hub domes to form height limiting devices. Vertical height increasing stress is applied to the hub, resulting in a decrease in the hub diameter. A fiber composite material rim may be wound upon the circumferential perimeter of the hub. This stationary height increased configuration of the hub permits the unitary structure to increase in diameter at high rotational velocities when subjected to severe centrifugal forces.

Abstract: A unitary, wide rim of fiber composite material for use in conjunction with flywheels for inertial energy storage apparatus, the rim being fabricated to minimize radial stresses and equalize hoop stresses ordinarily produced at high speed rotation of the flywheel. Novel fabrication techniques include varying the density of the rim as a function of radius by means of ballasting; varying the ratio of the fiber and epoxy mixture as a function of radius; varying the winding tension of the fiber as a function of radius; using a combination of layers of fibers having different modulus of elasticity; and varying the winding geometry of the fiber from non-circular to circular as a function of radius. By utilizing two or more of the aforesaid novel fabrication techniques, a preferred embodiment of a unitary, thick flywheel rim achieves radial stress reduction to trivial levels and hoop stress equalization sufficient to permit extremely efficient energy storage as a function of flywheel weight.