Resolver

Abstract

A resolver includes excitation coils and a detection coil. One of the excitation coils and the detection coil includes a sine coil and a cosine coil that transmit AC signals having phases of the electrical angle different from each other by 90 degrees. Further, the other coil is provided with an annular magnetic pole group in which a plurality of magnetic poles is disposed adjacent to each other in the circumferential direction at a facing face at which the rotor and the stator face each other. The plurality of sine coils and the plurality of the cosine coils are alternately disposed adjacent to each other in the circumferential direction at the facing face. The circumferential intervals between the magnetic poles included in the excitation coils and the detection coil are identical.

1 . A resolver that detects a rotation angle of a rotor with respect to a stator, the resolver comprising:
 a sheet-like excitation coil provided at the rotor or the stator; and   a sheet-like detection coil provided at the rotor or the stator, wherein   one of the excitation coil and the detection coil includes a plurality of sine coils and a plurality of cosine coils that transmit AC signals having phases of an electrical angle different from each other by 90 degrees,   the other of the excitation coil and the detection coil has an annular magnetic pole group in which a plurality of magnetic poles is disposed adjacent to each other in a circumferential direction at a facing face at which the rotor and the stator face each other,   the plurality of sine coils and the plurality of cosine coils are circumferentially disposed alternately adjacent to each other at the facing face, and   intervals in a circumferential direction between magnetic poles included in the excitation coil and the detection coil are identical.   
     
     
         2 . The resolver according to  claim 1 , wherein
 each of the sine coils and each of the cosine coils are disposed in a partial annular region surrounded by an inner circle and an outer circle around a rotation axis of the rotor and two straight lines passing through the center at the facing face, and have a structure in which at least part of the each sine coil and at least part of the each cosine coil are each configured by a corrugated coil.   
     
     
         3 . The resolver according to  claim 1 , wherein
 each of the sine coils and each of the cosine coils have a structure in which a pair of comb-shaped closed coils connected to each other is disposed so as not to overlap each other in the partial annular region, and   the pair of comb-shaped closed coils includes a first comb-shaped closed coil in which a conductor is routed so as to form an outline of a comb having teeth extending from an arc of the outer circle toward an arc of the inner circle, and a second comb-shaped closed coil in which a conductor is routed so as to form an outline of a comb having teeth extending from an arc of the inner circle toward an arc of the outer circle.   
     
     
         4 . The resolver according to  claim 1 , wherein
 the sine coils and the cosine coils are alternately disposed adjacent to each other in respective regions obtained by equally dividing the facing face by straight lines passing through a rotation axis of the rotor into an even number at the facing face.   
     
     
         5 . The resolver according to  claim 1 , wherein
 the sine coils and the cosine coils include an identical number of rotationally symmetric coils in which directions of magnetic fluxes caused by excitation are different from each other.   
     
     
         6 . The resolver according to  claim 1 , wherein
 in the excitation coils or the detection coils, at least one of gaps between a plurality of coils whose adjacent coils have each gap is wider than the other gaps, and positions of a start end and a terminal end of one of the adjacent coils having the wider gap are different from positions of a start end and a terminal end of the other of the adjacent coils in an electrical angle by N cycles ±90 degrees.   
     
     
         7 . The resolver according to  claim 1 , wherein
 the sine coils and the cosine coils are routed so as to form a rotationally symmetric shape with respect to a rotation axis of the rotor.   
     
     
         8 . The resolver according to  claim 1 , wherein
 the excitation coil and the detection coil are both provided at the stator, and   the rotor includes a conductor that generates a diamagnetic field in a direction of canceling a magnetic field of the excitation coil with a magnitude according to the rotation angle.   
     
     
         9 . The resolver according to  claim 1 , wherein
 the excitation coil is disposed on one side of the rotor and the stator, and the detection coil is disposed on the other side of the rotor and the stator so as to face the excitation coil.