Electric motor and compressor having electric motor

An electric motor, comprising:

• a stator having a stator core and a stator coil;
• and
• a rotor provided with a rotational shaft and rotatably disposed with respect to the stator, wherein the stator coil includes a main winding, an auxiliary winding connected to the main winding with a phase difference, and a capacitor connected to the auxiliary winding in series,
• wherein the main winding includes a first main winding and a second main winding configured to be connected to each other and disconnected from each other,
• wherein the stator coil further includes a winding changeover switch configured to allow connection and disconnection between the first main winding and the second main winding, the winding changeover switch including a fixed terminal, and a movable terminal configured to be elastically deformable during electrical connection,
• wherein the rotor includes a rotor core coupled to the rotational shaft and a plurality of conductor bars coupled to the rotor core,
• wherein the first main winding and the second main winding have a different number of turns,
• wherein the first main winding and the second main winding comprise conductors each having a diameter smaller than a diameter of a conductor of a single main winding,
• wherein a sum of a number of turns of the first main winding and a number of turns of the second main winding is greater than a number of turns of the single main winding, and
• wherein the number of turns of the first main winding is 70% to 95% of the number of turns of the main winding.

An electric motor, comprising:

• a stator having a stator core and a stator coil;
• and
• a rotor provided with a rotational shaft and rotatably disposed with respect to the stator,
• wherein the stator coil includes a main winding, an auxiliary winding connected to the main winding with a phase difference, and a capacitor connected to the auxiliary winding in series,
• wherein the main winding includes a first main winding and a second main winding configured to be connected to each other and disconnected from each other,
• wherein the stator coil further includes a winding changeover switch configured to allow connection and disconnection between the first main winding and the second main winding, wherein the winding changeover switch is configured to:
• connect the first main winding and the second main winding in series when the rotor is stationary;
• and
• disconnect the first main winding and the second main winding from each other so that one of the first main winding or the second main winding is operated when an output reaches a predetermined value,
• wherein the rotor includes a rotor core coupled to the rotational shaft and a plurality of conductor bars coupled to the rotor core,
• wherein the first main winding and the second main winding have a different number of turns,
• wherein the first main winding and the second main winding comprise conductors each having a diameter smaller than a diameter of a conductor of a single main winding,
• wherein a sum of a number of turns of the first main winding and a number of turns of the second main winding is greater than a number of turns of the single main winding, and
• wherein the number of turns of the first main winding is 70% to 95% of the number of turns of the main winding.