Abstract: A flywheel assembly for storing energy and rotatable in response to the rotation of a shaft includes a hub having a transition portion having a constant stress intermediate region operatively coupled to the shaft and an outer connecting portion forming a flexible cylinder, wherein the shaft and the flexible cylinder are substantially coaxial, and an outer cylinder wherein a majority of the mass of the flywheel assembly is concentrated. The flexible cylinder includes connecting pads disposed at opposing edges of the outer side of the flexible cylinder thereby permitting connection to the outer cylinder. The outer cylinder increases radially responsive to a corresponding increase in rotational speed of the flywheel assembly, while the diameter of the transition portion of the hub follows the radial increase of the outer cylinder.

Abstract: A flywheel safety support system isolates the flywheel and its motor-generator from the driving environment of an electrically powered motor vehicle. A suitable liquid, placed between the outer and vacuum housings of the flywheel assembly, provides buoyancy and damping to the vacuum housing, cooling of the motor-generator, and serves as one of the barriers to rotor energy and angular momentum transfer in the event of an accident or failure. During normal operation, a shearable mechanical gimbal system keeps the vacuum housing centered in the outer housing, reacts the spin moments generated by the motor-generator, and provides a path for the electrical leads into the vacuum housing. In the event of bearing seizure or rotor failure, the mechanical gimbal will shear and allow the vacuum housing to gradually spin down against the fluid. A fiber barrier provides an additional layer of protection to passengers.

Abstract: A bearing system for positioning and supporting a rotor having a vertical shaft (20) coincident with a main rotation axis included in a flywheel (10) used for energy storage and high surge power in vehicular applications. The bearing system includes upper and lower radial force generators (110, 210) containing only electromagnets, and upper and lower axial force generators (120, 220) including an electromagnet and a permanent magnet. According to one aspect of the bearing system, each of the bearings includes control circuitry having simple and complex lead networks so as to permit the force generators to rapidly respond to vehicular transients while maintaining a preferred bearing stiffness. The bearing system also includes upper and lower touchdown ball bearings (130, 230) which are engaged only when the radial force generators are unable to maintain the rotor in a predetermined cylindrical volume within the flywheel (10).

Abstract: A capacitive sensor system for an active magnetic bearing supporting a rotating shaft and flywheel in a flywheel energy storage system integrates sensor elements into the bearing stators, thereby conserving valuable space within a vacuum housing enclosing the flywheel energy storage system. High frequency resonant processing provides intrinsic linearity and noise immunity while permitting fast response times. Simple design of the sensor system permits all sensor electronics to be readily packaged within the vacuum housing.

Abstract: A field control system for a wound rotor synchronous motor-generator used in electrically powered automobiles is capable of optimizing the performance of the motor-generator for all driving conditions. Using a rotary transformer to transmit power across the rotational boundary, it has no wearing parts and is silent. Preferably, the field control system has common elements with the controller which generates the stator currents of the synchronous motor-generator.

Abstract: A flywheel support system isolates the flywheel (11) and its motor-generator (21) from the driving environment of an electrically powered motor vehicle. A suitable liquid (9), placed between the outer (8) and vacuum (10) housings of the flywheel assembly, provides buoyancy and damping to the vacuum housing, cooling the motor-generator, and serves as one of the barriers to rotor energy and angular momentum transfer in the event of and accident or failure. During normal operation, a shearable mechanical gimbal system (80) keeps the vacuum housing centered in the outer housing, reacts the spin moments generated by the motor-generator, and provides a path for the electrical leads into the vacuum housing. In the event of bearing seizure or rotor failure, the mechanical gimbal will shear and allow the vacuum housing to gradually spin down against the fluid. A system of angular-contact oil-lubricated ball bearings (12, 13) supports the rotating assembly including the rotor (21b) of the motor-generator.

Abstract: A bearing system for positioning and supporting a rotor having a vertical shaft coincident with a main rotation axis included in a flywheel used for energy storage and high surge power in vehicular applications includes first and second radial force generators disposed in a first plane perpendicular to the rotation axis of the rotor, the first and second force generators including only electromagnets, third and fourth radial force generators disposed in a second plane perpendicular to the rotation axis of the rotor, the third and fourth force generators including only electromagnets, and upper and lower axial force generators each containing an electromagnet and a permanent magnet. According to one aspect of the bearing system, each of the force generators includes control circuitry having simple and complex lead networks so as to permit the force generators to rapidly respond to vehicular transients while maintaining a desired bearing stiffness.

Abstract: A flywheel support system isolates the flywheel and its motor-generator from the driving environment of an electrically powered motor vehicle. A suitable liquid, placed between the outer and vacuum housings of the flywheel assembly, provides buoyancy and damping to the vacuum housing, cooling of the motor-generator, and serves as one of the barriers to rotor energy and angular momentum transfer in the event of an accident or failure. During normal operation, a shearable mechanical gimbal system keeps the vacuum housing centered in the outer housing, reacts the spin moments generated by the motor-generator, and provides a path for the electrical leads into the vacuum housing. In the event of bearing seizure or rotor failure, the mechanical gimbal will shear and allow the vacuum housing to gradually spin down against the fluid. A system of both active and passive axial and radial magnetic bearings supports the rotating assembly including the rotor of the motor-generator.

Abstract: A flywheel assembly used for mobile energy storage incorporates a molecular pump and an internal chamber containing molecular sieves. The molecular pump shares the shaft, bearings, and motor of the flywheel rotor, and maintains the high vacuum desired in the vicinity of the flywheel rotor. The gases which evolve from the rotor during its operational life are pumped into the chamber containing the molecular sieves where they are adsorbed.