Electromechanical flywheel with evacuation system
View Patent ↗An electromechanical flywheel machine includes a flywheel mass enclosed in an evacuable housing and an e×ternal gas removal train.
1. An electromechanical flywheel comprising:
a motor-generator rotor surrounding a motor-generator stator;
a flywheel mass configured to rotate with the motor-generator rotor;
the flywheel mass and the motor-generator rotor located inside an evacuable housing;
a gas removal train external to the evacuable housing;
the train including a mechanical vacuum pump and a non-mechanical gas removal device;
getter material and molecular sieve material in a casing of the non-mechanical gas removal device;
the train operable to fluidly couple the casing and the evacuable housing for lowering the pressure in the evacuable housing;
a pressure sensor configured to sense the pressure in the evacuable housing; and,
the mechanical pump configured to operate intermittently in accordance with differences between a pressure sensed by the pressure sensor and a threshold vacuum pressure level.
2. The electromechanical flywheel of claim 1 further comprising:
a gas removal train flowpath extending between the evacuable housing and the mechanical vacuum pump; and,
the casing in fluid communication with the flowpath via a single passageway.
3. The electromechanical flywheel of claim 2 further comprising:
a gas permeable structure;
the structure within the casing; and,
the structure separating the getter material and the molecular sieve material.
4. The electromechanical flywheel of claim 1 further comprising:
a gas removal train flowpath extending between the evacuable housing and the mechanical vacuum pump; and,
the casing in fluid communication with the flowpath via first and second passageways.
5. The electromechanical flywheel of claim 4 further comprising:
a casing inlet and a casing outlet;
the casing inlet proximate the getter material;
the casing outlet proximate the molecular sieve material; and,
flow from the casing inlet to the casing outlet being urged by operation of the mechanical vacuum pump.
6. The electromechanical flywheel of claim 5 further comprising:
a gas permeable structure;
the structure within the casing; and,
the structure separating the getter material and the molecular sieve material.
7. The electromechanical flywheel of claim 1 further comprising:
a gas removal train flowpath extending between the evacuable housing and the mechanical vacuum pump;
the casing in fluid communication with the flowpath via first and second passageways;
a first pressure sensor sensing pressure between the evacuable housing and the non-mechanical gas removal device;
a second pressure sensor sensing pressure between the non-mechanical gas removal device and the mechanical vacuum pump;
a heater for heating the molecular sieve material; and,
the heater configured to operate intermittently in accordance with differences between pressures sensed by the first and second pressure sensors as compared with a threshold pressure difference.
8. An electromechanical flywheel comprising:
a core assembly including a motor-generator stator;
a motor-generator rotor surrounding the motor-generator stator;
the motor-generator stator defining an axis of rotation, having a field coil that encircles the axis of rotation, and having an armature coil that does not encircle the axis of rotation;
a flywheel mass encircling the motor-generator rotor and coupled to the motor-generator rotor for rotation with the motor-generator rotor;
an evacuable housing enclosing the motor-generator rotor and the flywheel mass;
a gas removal train external to the evacuable housing;
the train including a mechanical vacuum pump and a non-mechanical gas removal device;
getter material and molecular sieve material in a casing of the non-mechanical gas removal device;
the train operable to fluidly couple the casing and the evacuable housing for lowering the pressure in the evacuable housing;
a pressure sensor configured to sense the pressure in the evacuable housing; and,
the mechanical pump configured to operate intermittently in accordance with differences between a pressure sensed by the pressure sensor and a threshold vacuum pressure level.