FLYWHEEL SYSTEM FOR MOBILE ENERGY STORAGE

摘要

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. A squeeze film damper (145) associated with the lowermost bearing (13) minimizes mechanical vibrations. A molecular drag pump (26) maintains a high vacuum for the rotating assembly. The placement of the center of gravity of the vacuum housing and its contents below the center of buoyancy produces a vertical orientation of the vacuum housing in the absence of accelerations, allowing the offloading of the flywheel rotor weight by a magnet (23).