초록 ▼

An electromagnetic actuator has a stator and an armature both made of magnetically permeable material and each having a plurality of projecting poles spaced apart from each other. The armature poles and stator poles cooperate with each other so that each pair of opposed pole faces of an armature pol

An electromagnetic actuator has a stator and an armature both made of magnetically permeable material and each having a plurality of projecting poles spaced apart from each other. The armature poles and stator poles cooperate with each other so that each pair of opposed pole faces of an armature pole and a stator pole form a narrow working air gap for passing magnetic flux between the opposed pole faces. An electrically energizable coil produces magnetic flux which passes through the poles of the armature and stator and across the working air gaps. Selected pairs of the opposed armature and stator poles form a substantially constant air gap so that the attracting magnetic force on the armature increases as the armature moves in a first direction relative to the stator and decreases as the armature moves in the opposite direction, and other pairs of the opposed armature and stator poles form a variable air gap so that the attracting magnetic force on the armature decreases as the armature moves in the first direction and increases as the armature moves in the opposite direction.

대표청구항 ▼

An electromagnetic actuator comprising a stator and a rotor both made of magnetically permeable material and each having a plurality of projecting poles spaced apart from each other, the rotor poles and stator poles cooperating with each other so that each pair of opposed pole faces of a rotor pole

An electromagnetic actuator comprising a stator and a rotor both made of magnetically permeable material and each having a plurality of projecting poles spaced apart from each other, the rotor poles and stator poles cooperating with each other so that each pair of opposed pole faces of a rotor pole and a stator pole form a narrow working air gap for passing magnetic flux between the opposed pole faces, an electrically energizable coil for producing magnetic flux that passes through the poles of said rotor and stator and across the working air gaps between the opposed pole faces, at least one pair of the opposed rotor and stator poles forming an air gap that remains substantially constant to produce an increasing magnetic torque on said armature as said pole faces move out of register with each Other and a decreasing magnetic torque as said pole faces move toward register with each other, and at least one pair of the opposed rotor and stator poles forming an air gap that varies to produce a decreasing magnetic torque on said rotor as the poles forming the constant air gap move out of register with each other and increasing magnetic torque as the poles forming the constant air gap move toward register with each other, whereby the change in the magnetic torque produced by said poles forming the variable air gap at least partially compensates for the change in the magnetic torque produced by the poles forming the constant air gap.