A method of de-spinning a rotor of a propulsion system includes providing one or more spinning rotors rotatably mounted on a frame with a bearing having a bearing outer race, bearing balls, and bearing inner race; providing a force mechanism coupled with the one or more spinning rotors for applying a load to the one or more spinning rotors; and loading an outer portion of the outer bearing race, bearing ball, and inner bearing race of the bearing, a load on the outer portion of the bearing race, bearing ball, and inner bearing race of the bearing corresponding to a force applied to the one or more spinning rotors by the drive mechanism. The one or more spinning rotors de-spin at a rate corresponding to the load on the bearing balls.

A method of de-spinning a rotor of a propulsion system includes providing one or more spinning rotors rotatably mounted on a frame with a bearing having a bearing outer race, bearing balls, and bearing inner race; providing a force mechanism coupled with the one or more spinning rotors for applying a load to the one or more spinning rotors; and loading an outer portion of the outer bearing race, bearing ball, and inner bearing race of the bearing, a load on the outer portion of the bearing race, bearing ball, and inner bearing race of the bearing corresponding to a force applied to the one or more spinning rotors by the drive mechanism. The one or more spinning rotors de-spin at a rate corresponding to the load on the bearing balls.

A method of manufacturing a stacked core includes forming a first pilot hole in a metal plate, forming a worked portion of the metal plate in a state in which a first pilot pin is inserted into the first pilot hole, the worked portion being displaced relative to a plane of the metal plate, press-fitting the worked portion of the metal plate to reposition the worked portion to extend along the plane of the metal plate, forming a second pilot hole in the metal plate after press-fitting the worked portion of the metal plate, and forming a blanked member by blanking the metal plate in a state in which a second pilot pin is inserted into the second pilot hole, the blanked member including the worked portion.

A method of manufacturing a stacked core includes forming a first pilot hole in a metal plate, forming a worked portion of the metal plate in a state in which a first pilot pin is inserted into the first pilot hole, the worked portion being displaced relative to a plane of the metal plate, press-fitting the worked portion of the metal plate to reposition the worked portion to extend along the plane of the metal plate, forming a second pilot hole in the metal plate after press-fitting the worked portion of the metal plate, and forming a blanked member by blanking the metal plate in a state in which a second pilot pin is inserted into the second pilot hole, the blanked member including the worked portion.

The present disclosure relates to an electric motor, and a compressor having the same. The electric motor includes a stator, and a rotor. The rotor includes a rotation shaft, a rotor core, and a plurality of permanent magnets. The rotor core includes permanent magnet insertion portions each formed therethrough in an axial direction so that the permanent magnet is inserted, and slots each formed through the rotor core in a manner that a core area of a front portion of a d-axis is smaller than a core area of a rear portion of the d-axis in a rotating direction of the rotor when an outer core part of the permanent magnet insertion portion is divided with respect to the d-axis. Accordingly, a decrease in inertia can be suppressed and an occurrence of vibration and noise due to Magnetic Pull Force (MPF) can be prevented.

The present disclosure relates to an electric motor, and a compressor having the same. The electric motor includes a stator, and a rotor. The rotor includes a rotation shaft, a rotor core, and a plurality of permanent magnets. The rotor core includes permanent magnet insertion portions each formed therethrough in an axial direction so that the permanent magnet is inserted, and slots each formed through the rotor core in a manner that a core area of a front portion of a d-axis is smaller than a core area of a rear portion of the d-axis in a rotating direction of the rotor when an outer core part of the permanent magnet insertion portion is divided with respect to the d-axis. Accordingly, a decrease in inertia can be suppressed and an occurrence of vibration and noise due to Magnetic Pull Force (MPF) can be prevented.

A wound rotor, such as a wound rotor for an electric machine, includes a shaft having a main axis. The shaft includes a manifold. The wound rotor also includes a winding wire and n poles wound and ordered with an ascending order number obtained by rotation about the main axis. The n wound poles can be distributed radially about the main axis. The n poles are wound with the wire in series in turn according to their ascending order numbers, the last pole, however, not being wound last.

A wound rotor, such as a wound rotor for an electric machine, includes a shaft having a main axis. The shaft includes a manifold. The wound rotor also includes a winding wire and n poles wound and ordered with an ascending order number obtained by rotation about the main axis. The n wound poles can be distributed radially about the main axis. The n poles are wound with the wire in series in turn according to their ascending order numbers, the last pole, however, not being wound last.

A rotor for an electric motor includes: a rotating element extending along an axis; and a retaining body formed of metal and configured to hold the rotating element from an outer peripheral side, where the retaining body includes: a plurality of annular members annularly surrounding an outer peripheral surface of the rotating element and arranged at intervals in the axis direction; and a plurality of connecting members arranged in a circumferential direction between the annular members adjacent to each other so as to connect the annular members. As a result, a path of eddy current is limited and the eddy current can be reduced.

An electric motor has a rotor and a stator (1) with a first winding space (11) to receive a multiplicity of coil windings (12) wound from a winding wire. A second winding space (20), connected to the respective first winding space (11), is provided as a winding space extension of the first winding space (11) in order to receive at least one wire portion (21) of the winding wire. Two receiving pockets (24, 25), situated opposite one another in the circumferential direction (U), are formed in the at least one second winding space (20) in order to respectively receive the at least one wire portion (21) of the winding wire.