High Temperature Superconducting Magnetic Levitation

5.7 HTS Maglev bearing measurement system Ë 147

This measurement system can accomplish the automatic test of various mechanical,
electromagnetic, and temperature performances of HTS Maglev bearing at static and
dynamic conditions, which will provide strong technical support for the development
and engineering applications of HTS Maglev bearing and flywheel energy storage
system (FESS).
The characteristics and special technical requirements for the HTS Maglev bearing
measurement system are:

1. Basic platform with high positioning accuracy.


2. Improved machining of the PM rotor and the assembly accuracy, in order to ensure
   structural stiffness and safety.


3. Very high concentricity between one PM rotor and the three stators (high-speed
   motor, HTS bearing, and PM bearing stator).


4. The system dynamic balance compensation for the best balance.


5. Shock absorption and vibration isolation for the test platform.


6. The precision machining and assembly of the arc plane for HTS bulks, in order to
   ensure the accuracy of the HTS Maglev bearings.


7. The cryogenic system of wide temperature region for automatic control.


8. The vacuum dynamic sealing device at the high speed.

The HTS Maglev bearing measurement system is mainly used for levitation characteri-
stic tests of the HTS Maglev bearing in static and dynamic operations, especially with
heavy load and high-speed conditions. The main functions include:

1. Real-time monitoring and recording of rotation rate.


2. Setting and monitoring of the running state for the high-speed electric spindle.


3. Measurements of axial and radial forces of the HTS Maglev bearing under static
   test.


4. Measurements of axial and radial relaxation time of the HTS Maglev bearing under
   static test.


5. Vibration characterization of HTS Maglev bearing under dynamic conditions.


6. Force characterization tests of bearing system at low temperature.


7. Measurements of temperature variation of HTS bulk at dynamic test.


8. Dynamics balance characterization of HTS bulk bearing at dynamic test.


9. Studies on influence of external disturbance on bearing performance under
   dynamic test.

Specifications of the HTS Maglev bearing measurement system:

1. The base size, 1.1×1.1 m.


2. Rotating speed, 020,000 rpm.


3. PM rotor diameter, 220 mm.


4. Test force range, (axial) 1500 kgf, (radial) 800 kgf.


5. Test temperature, 40–300 K.


6. The position precision,±0.05 mm (axial) and±0.01 mm (radial).