Harmonically graded airgap reluctance-type rotating electric resolver
AssigneePowerton, division of Contraves Goerz Corporation
InventorsAshok Nagarkatti, Robert E. Lordo, Burkhart Kind
Life of this patent
Estimating the term…
Abstract
This invention relates to a harmonically graded airgap reluctance-type rotating electric resolver. The magnetic permeance of the airgap is made to vary sinusoidally. Therefore, only the fundamental wave exists, free of higher harmonics. The invention has application in numerous fields, including commutation of brushless motors and to precisely position machinery tools relative to work pieces in numerically controlled machines.
Claims15
A reluctance-type resolver for an electric machine comprising a toothed stator having input and output windings thereon and a rotor rotatably positioned within said stator, wherein said rotor defines a periphery profiled to produce during rotation a smoothly varying airgap according to a formula wherein the inverse of the radial airgap at any predetermined point on the rotor is proportional to a constant plus the sine of the product of the number of lobes on said rotor and the angle between the predetermined point on the rotor and a reference point on the stator, whereby the magnetic permeance of the airgap varies sinusoidally.
A reluctance-type resolver according to clim 11 or 12, wherein each of the M.sub.1 input windings has P/M.sub.1 coils with all coils having effectively the same number of turns, and each of the M.sub.2 output windings has P/M.sub.2 coils with all coils having effectively the same number of turns which may or may not differ from the number of turns in an input coil.
Dependencies are inferred from the claim text.