초록 ▼

The invention, intended primarily for use in a steel flywheel power source (30), provides a vacuum system and a method of maintaining a vacuum inside a flywheel chamber (32) for the life of the power source (30). The vacuum system combines the use of cleaning and de-gassing treatments in the chamber

The invention, intended primarily for use in a steel flywheel power source (30), provides a vacuum system and a method of maintaining a vacuum inside a flywheel chamber (32) for the life of the power source (30). The vacuum system combines the use of cleaning and de-gassing treatments in the chamber (32) and vacuum tempering of the steel flywheel (31) with the use of a chemical type metal alloy nonevaporable getter, such as zirconium-vanadium-iron, that cooperatively matches the outgassing of the flywheel (31) and chamber (32) by sorbing those gases that are released. The getter may be reactivated throughout the life of the flywheel system by reheating it with an integral heater that is triggered by a timer instead of a vacuum gauge to increase the system reliability, using power taken directly from the energy stored in the flywheel. The electronics (45) of the flywheel power source are used to signal an alarm or prevent achieving or maintaining full speed of the flywheel when the vacuum in the chamber degrades.

대표청구항 ▼

We claim: 1. A vacuum system for a flywheel power source comprising: a metal chamber having walls with a thickness sufficient to resist atmospheric pressure when said chamber is evacuated; an energy storage flywheel constructed of steel and supported on a bearing system mounted in said chamber for

We claim: 1. A vacuum system for a flywheel power source comprising: a metal chamber having walls with a thickness sufficient to resist atmospheric pressure when said chamber is evacuated; an energy storage flywheel constructed of steel and supported on a bearing system mounted in said chamber for rotation about an axis; a motor/generator coupled to said flywheel for accelerating and decelerating said flywheel for storing and retrieving energy; said chamber being maintained at low pressure for the life of the flywheel power source by the use of a nonevaporable metal alloy chemical type getter; an electric heater in heat conducting relationship to said getter and connected in a circuit to a source of electrical energy for energizing said electric heater when required to activate and reactive said getter material. 2. A vacuum system for a flywheel power source as described in claim 1, further comprising: a timer in said circuit for connecting said source of electrical energy to said electric heater when reactivation of said getter is required. 3. A method for establishing and maintaining a vacuum in a flywheel power source that employs a steel flywheel coupled to a motor/generator and housed in a metal chamber, comprising: assembling said flywheel inside said chamber and sealing said chamber; heating said entire chamber to at least about 120 degrees F. while pulling a vacuum on said chamber for removal of internal gasses, contaminants and water vapor using a connection to an external vacuum pump; establishing communication between a separate vacuum pump and said chamber, said separate vacuum pump having a chemical type metal alloy nonevaporable getter material that can be activated by heating said getter material; and closing said vacuum connection between said chamber and said external vacuum pump and sealing said chamber completely. 4. A method for establishing and maintaining vacuum as describe in claim 3 wherein: reheating said getter during the life of said flywheel power source to reactivate said getter material through the use of a heater that is integral with the flywheel power source. 5. A method for establishing and maintaining vacuum as described in claim 4 wherein: the reactivation of the getter is triggered by a timer. 6. A method for establishing and maintaining vacuum as described in claim 4 wherein: energizing said heater using energy produced in said generator from said spinning flywheel. 7. A flywheel power source comprising: an energy storage steel flywheel supported on a bearing system for rotating about an axis; a motor/generator coupled to said flywheel for accelerating and decelerating the flywheel for storing and retrieving energy; a metal chamber surrounding said flywheel and adapted to be evacuated and maintained at a low pressure; electronics are connected to said motor for charging said flywheel by energizing said motor of said motor/generator, said electronics having detectors for detecting when the drag on said flywheel is normal, and thereafter preventing maintaining or achieving full speed. 8. A flywheel power source as described in claim 7 wherein: said prevention of maintaining or achieving full speed is achieved by current limiting to said motor. 9. A flywheel power source comprising: an energy storage flywheel constructed of steel and supported on a bearing system for rotation about an axis, a motor/generator is coupled to said flywheel for accelerating and decelerating the flywheel for storing and retrieving energy, a metal chamber enclosing said flywheel and maintained at a low pressure, electronics for controlling the charging and discharging of said flywheel power source, said electronics having a detector that activates a signal when aerodynamic drag on said flywheel is detected to be above normal. 10. A flywheel power source as described in claim 9 wherein: said detector detects above normal drag on said flywheel at a speed lower than full operating speed of said flywheel by the electronics calculation using the motor power, rotational speed and the flywheel acceleration. 11. A flywheel power source as described in claim 9, wherein: said flywheel includes a rotor having a principal rotating mass of steel, and said signal triggers reactivation of a chemical type metal alloy nonevaporable getter material by activating a heater in thermal contact with said getter material for heating said getter material to reduce said pressure and reduce said aerodynamic drag. 12. A method for maintaining vacuum in a flywheel power source having an energy storage flywheel coupled to a motor/generator for accelerating and decelerating the flywheel for storing and retrieving energy and supported on a bearing system for rotation inside a vacuum chamber enclosing said flywheel and maintained at a low pressure, comprising: determining an occurrence of increased pressure above a predetermined threshold inside said vacuum chamber with use of said flywheel motor power, flywheel speed and flywheel acceleration; and triggering the vacuum to be reestablished upon said determination of increased pressure. 13. A method as described in claim 12, wherein: said vacuum is reestablished by reactivating a chemical type metal alloy nonevaporable getter through use of a heater. 14. A method as described in claim 12 wherein: said flywheel has a steel rotor and said increased pressure inside said vacuum chamber is less than 10-3 Torr. 15. A method as described in claim 12 wherein: said steel flywheel has a steel rotor that has been tempered by heating said solid steel rotor to a temperature of between 800째 F. and 1200째 F. and holding it at that temperature for more than one hour. 16. A method as described in claim 12 wherein: said electronics of said flywheel power source prevent said motor from maintaining full speed of said flywheel when the pressure in the vacuum chamber exceeds a predetermined minimum pressure, as determined by increased aerodynamic drag on said flywheel. 17. A method as described in claim 16 wherein: said electronics limit current to the motor when said pressure in said vacuum chamber exceeds said predetermined minimum pressure. 18. A method for reducing outgassing from elements of an energy storage flywheel system having a forged and quenched steel flywheel and a metal container for holding said flywheel and adapted to be evacuated to provide an evacuated space in which said flywheel can spin at high speed with little aerodynamic drag, comprising: tempering said flywheel material in a vacuum. 19. A method as described in claim 18, further comprising: tempering said metal container in a vacuum. 20. A method as described in claim 18 wherein: said forged steel flywheel is heat treated at above about 1500째 F. and then is tempered in said tempering step; and said tempering step includes heating said steel flywheel to a temperature of between 800째 F. and 1200째 F. and holding it at that temperature for more than one hour at a pressure of no greater than about 10-4 Torr.