Patent GB-1481565-A (GB)
Title: Inertial energy storage apparatus
IPC: F16F15/30
Filed: 1974-07-19
Abstract: 1481565 Energy storage devices S F POST 19 July 1974 [19 July 1973] 32207/74 Heading F2X [Also in Division B7] A rotor for an inertial energy storage apparatus, suitable in particular for vehicle propulsion, comprises loading means disposed in at least some of a plurality of annular radial zones of the rotor, the elasticity-density ratios of the zones increasing with mean radius of the rotor. By "elasticity-density ratio" is meant the quotient of the circumferential Young's modulus of a particular zone divided by the mean density of that zone. In one embodiment (Fig. 2) a rotor of similar construction to that described in Specification 1,368,648 has a rim or felly 140 comprising a plurality of high-strength rings 150 fabricated for example from intertwisted poly-p-benzamide strands 276 bonded together by means of an epoxy resin and embedded in a matrix 152 fabricated from an epoxy-polymer compound which is loaded with lead powder. The matrix 152 comprises eight toroidal regions 274 defined by cylinders 260 to 268 and the amounts of lead powder decrease from one region to the next in the radial outward direction. The lead powder can be so distributed that the centrifugal separation index of each pair of toroidal felly portions 270-1 to 270-8 (defined by the cylinders 260 to 268) is greater than zero, e.g. approximately 2, whereby the toroidal felly portions undergo substantially the same percentage distortion due to centrifugal force at a given rotor speed, within the elastic limits of the ring and matrix materials, and thus the stresses in the matrix will be substantially uniform throughout the felly, or approximately 3, whereby the toroidal felly portions substantially "follow" each other as the rotor speed is increased. By "centrifugal separation index" in connection with a particular pair of toroidal felly portions is meant the power to which the quotient of the mean radius of the larger diameter portion divided by that of the smaller diameter portion must be raised to equal the quotient of the elasticity-density ratio of the larger diameter portion divided by that of the smaller diameter portion. In an alternative embodiment, shown in Figs. 4 and 5, the high-strength rings 280 are of rectangular cross-section and embedded in a matrix 284. Within each felly portion defined by cylinders 290 to 298, loading members in the form of tungsten strips 286 are disposed within the rings 280 of that same portion, thus loading the rings centrifugally. The strips 286 are of rectangular cross-section and extend from top to bottom of the felly. The number of strips 286 decreases from, e.g. 174, in the innermost felly portion to zero in the outermost portion. In an alternative embodiment (Fig. 6, not shown) the loading members are granules of tungsten powder. In either case, certain of the high-strength rings 280 (300) of the outer felly portion can be made more susceptible to rupture than the others, as by notching, so as to ensure that should the rotor be operated beyond its maximum operating speed, only the rings of the outer felly portion will fail. The rupture of only one such "weak" ring will bring about the piercing of the inner evacuated shell 16 but not the outer liquid-filled tank (18) (Fig. 1, not shown), thus causing the shell 16 to rapidly fill with liquid so as to rapidly dissipate the remaining energy stored in the rotor.  The rotor has an alternator-motor 46 in its hub 44 by means of which it can be brought to speed, and by means of which the inertial energy stored in it can be extracted in the form of an alternating output voltage and used, for example, to drive a passenger-carrying vehicle.