CONTROL DEVICE FOR MAGNETIC BEARING

• Main Authors: NAKAMURA ATSUSHI, MIYAMOTO MATSUTARO
• Format: Patent
• Language: English
• Published: 30.09.1997
• Edition: 6
• Subjects: BEARINGS; BLASTING; ELEMENTS OR CRANKSHAFT MECHANISMS; ENGINEERING ELEMENTS AND UNITS; FLEXIBLE SHAFTS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MECHANICAL ENGINEERING; ROTARY BODIES OTHER THAN GEARING ELEMENTS; SHAFTS; THERMAL INSULATION IN GENERAL; WEAPONS

PROBLEM TO BE SOLVED: To stably float and support a rotary shaft in an objective position without effecting troublesome offset regulation needed each time the length of a cable is differed. SOLUTION: A bearing device is formed such that displacement of a rotary shaft 10 is detected by a position sensor 15. By feedback control of a detecting displacement signal to the magnetic attraction force of a pair of electromagnets, positioned facing each other, by compensating the phase of an offset regulating displacement signal, the rotary shaft is supported in a non-contact state between the magnetic poles of a pair of electromagnets. In this case, two coils 16A and 16B having magnetic poles positioned facing each other of which the position sensor 15 consists are interconnected in series. Similarly, two pseudo inductance elements 30A, 31A, 31B, and 30B, equivalent to each other, are interconnected in series and connected to two coils in parallel. A signal source 17 is connected between the two terminals of the two coils, interconnected in series, or the two ends of a pseudo inductance element. A differential output is fetched from respective middle points between the two coils and between the pseudo inductance elements.