Resolver device, motor, and actuator
A resolver device includes a stator core and a rotor core supported so as to be freely rotatable with respect to the stator core and configured such that a reluctance component in a gap between the rotor core and the stator core changes in accordance with a relative angle position to the stator core. The stator core includes stator main poles and stator interpoles.
1. A resolver device comprising:
a stator core that includes:
a plurality of stator main poles, the number of which is an even multiple of three that is the number of phases, and that are arranged along a circumferential direction of a ring-shaped stator base such that respective exciting coils output three-phase output signals each of which is shifted by an electrical angle of +120 degrees or an electrical angle of −120 degrees in response to a one-phase excitation input signal; and
a plurality of stator interpoles for the respective phases that are wound around by respective exciting coils connected in series to the exciting coils wound around the corresponding stator main poles, and that are arranged at a position shifted by an electrical angle of +90 degrees or an electrical angle of −90 degrees with respect to at least one of the corresponding stator main poles;
a rotor core supported so as to be freely rotatable with respect to the stator core and configured such that a reluctance component in a gap between the rotor core and the stator core changes in accordance with a relative angle position to the stator core; and
a detection circuit that converts resolver current signals for the respective phases, which are output by connecting in series the exciting coils wound around the corresponding stator main poles to the exciting coils wound around the corresponding stator interpoles, into resolver voltage signals, and then subjects the resolver voltage signals to three-phase/two-phase conversion to obtain two-phase resolver signals.
2. The resolver device according to claim 1 , wherein
the rotor core includes rotor teeth projecting to a side facing the stator core, and
when the number of the stator main poles is P and the number of the rotor teeth is q, the following Equation (1) is satisfied:
P =( q/ ( M + ( N ± 1)/ N )) (1)
where
N is three that is the number of the phases, and M is an integer variable that satisfies the Equation (1).
3. A motor comprising the resolver device according to claim 2 , wherein
the rotor core rotates in conjunction with a motor rotor,
the resolver device is capable of detecting rotation of the motor rotor, and
the motor includes pole pairs, the number of which is the same as the number of the teeth q of the rotor core.
4. The resolver device according to claim 2 , wherein q in the Equation (1) is ten.
5. A motor comprising the resolver device according to claim 1 , wherein
the rotor core rotates in conjunction with a motor rotor, and
the resolver device is capable of detecting rotation of the motor rotor.
6. An actuator comprising the resolver device according to claim 1 , wherein
the actuator is capable of transmitting rotary motion that is detectable by the resolver device.