RING-TYPE MOTOR AND PHOTOGRAPHING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a ring-type motor which suppresses rotation non-uniformity with rotation and can be manufactured easily and at low costs, on the other hand.SOLUTION: The ring-type motor includes a rotor (first member) 32 and a stator (second member) 31 which can be rotated relatively, S magnetic poles (S) and N magnetic poles (N) are alternately arrayed in a circumferential direction in the rotor, and a coil 34 is disposed in the stator 31. The magnetic poles (S) and (N) are formed from S poles and N poles of a plurality of magnets 35 arrayed in the circumferential direction, respectively. In each of the magnetic poles (S) and (N), magnetic fluxes of the S poles or the N poles of the plurality of magnets 35 become a combined magnetic flux density and the magnetic flux density in a rotating direction can be made smooth, thereby suppressing rotation non-uniformity.