Resolver
Disclosed is a resolver, which includes a stator made of a magnetic material and having a plurality of teeth and a plurality of slots alternately formed at an inner side thereof; insulation covers respectively having a tooth insulating unit formed at an inner side thereof corresponding to the teeth and mounted to the stator at both upper and lower surfaces of the stator; and coils wound on the teeth with the tooth insulating unit being interposed therebetween, wherein a coil occupying ratio per slot, which is defined by the following equation and represents a ratio of area occupied by the coils in a slot to which the insulation covers are fixed, is 35% or below: Coil occupying ratio per slot=(area occupied by coils in a single slot)/(area of a single slot) Equation.
1. A resolver, comprising:
a stator made of a magnetic material and having a plurality of teeth and a plurality of slots alternately formed at an inner side thereof;
insulation covers respectively having a tooth insulating unit formed at an inner side thereof corresponding to the teeth and mounted to the stator at both upper and lower surfaces of the stator; and
coils wound on the teeth with the tooth insulating unit being interposed therebetween,
wherein a coil occupying ratio per slot, which is defined by following equation and represents a ratio of area occupied by the coils in a slot to which the insulation covers are fixed, is 3% to 35%:
Coil occupying ratio per slot=(area occupied by coils in a single slot)/(area of a single slot) Equation 1.
2. The resolver according to claim 1 , wherein the coils include an excitation coil of one phase or more and an output coil of one phase or more.
3. The resolver according to claim 1 , further comprising:
a rotor made of a magnetic material and configured to rotate based on a rotary shaft to change a gap permeance together with the stator.
4. The resolver according to claim 3 , wherein the rotor is an inner-type rotor disposed at an inner center of the stator.
5. The resolver according to claim 4 , wherein the rotor is ring-shaped having a through hole formed at a center portion thereof so that the rotary shaft is inserted therein and a plurality of salient poles formed at an outer circumference thereof to change the gap permeance.
6. The resolver according to claim 5 , wherein the salient pole has an arc shape with a diameter smaller than at least a diameter of the rotor.
7. The resolver according to claim 6 , wherein a center of the arc is disposed spaced apart from a center of the rotor by a predetermined distance, and the arcs of the plurality of salient poles have the same diameter.