A pole-number-changing rotary electric machine includes: a rotary electric machine; an n-group inverter; and a control unit for controlling the n-group inverter, wherein the control unit controls current phases of a current flowing through stator coils such that a current phase degree of freedom, which is a number of current phases per pole pair controllable by the n-group inverter, is equal to a number of groups n×a number of phases m/2 at a time of high polarity driving and the number of groups n×the number of phases m at a time of low polarity driving, where the number of groups n is a multiple of 4 and the number of phases m is a natural number of 3 or more and relatively prime to the number of groups n.

An electric motor has a stator defining multiple stator poles with associated electrical windings, and a rotor having multiple rotor poles. The rotor has flux barriers between adjacent rotor poles, the flux barriers each having a material with an electrical conductivity higher than the rotor pole material. The flux barriers are electrically isolated from one another external to the ferromagnetic material. Eddy currents are induced in the flux barrier to cause destructive interference of an impending magnetic field, such that the flux barrier effectively acts to inhibit magnetic flux during motor operation, which in some cases will result in a repulsive force that will act to increase an induced motive force on the rotor poles.

An electric motor has a stator defining multiple stator poles with associated electrical windings, and a rotor having multiple rotor poles. The rotor has flux barriers between adjacent rotor poles, the flux barriers each having a material with an electrical conductivity higher than the rotor pole material. The flux barriers are electrically isolated from one another external to the ferromagnetic material. Eddy currents are induced in the flux barrier to cause destructive interference of an impending magnetic field, such that the flux barrier effectively acts to inhibit magnetic flux during motor operation, which in some cases will result in a repulsive force that will act to increase an induced motive force on the rotor poles.

A rotating electric machine includes a cover formed in a cylindrical shape and extending in an axial direction to cover the controller section, a lid section disposed inside of the cover body to seal the cover body, a first sealing member compressed between the lid section and the cover, and a second sealing member compressed in a different direction than the first sealing member between the cover and the first frame or the second frame. The rotating electric machine also includes a tab formed on an outer periphery of the first frame or the second frame, and a claw extending from the one end of the cover body and engageable with the tab to hold the sealing members in a compressed state. As a result, the rotating electric machine is sealed from dust and water.

Various embodiments include a rotor for an electric machine comprising: an electric coil arrangement; and a winding carrier mechanically carrying the coil arrangement and at least partially enclosing the coil arrangement on a radially outer side of the coil arrangement. The rotor includes an inner cavity for circulating a fluid coolant such that the coil arrangement comes into contact with the liquid coolant on its radially inner side as the rotor rotates.

Various embodiments include a rotor for an electric machine comprising: an electric coil arrangement; and a winding carrier mechanically carrying the coil arrangement and at least partially enclosing the coil arrangement on a radially outer side of the coil arrangement. The rotor includes an inner cavity for circulating a fluid coolant such that the coil arrangement comes into contact with the liquid coolant on its radially inner side as the rotor rotates.

An actuator apparatus is described as having a stator device, a cover device, a contact device and an attenuation device. The stator device and the cover device are joined in such a manner so that a hollow space is formed between the stator device and the cover device. The cover device has an opening, through which the contact device is guided into the hollow space, so that the contact device runs at least partially in the hollow space and at least partially in the cover device. The attenuation device is positioned in the opening in such a manner so that a high-frequency electromagnetic radiation that travels through the opening is more highly attenuated by the attenuation device than the radiation would be attenuated without the presence of the attenuation device.

A ring varistor-based method for reducing electromagnetic interference of a motor, a corresponding motor commutator, and the motor. The method comprises: forming a counter bore in an end portion of a motor commutator; and placing a ring varistor into the counter bore

A ring varistor-based method for reducing electromagnetic interference of a motor, a corresponding motor commutator, and the motor. The method comprises: forming a counter bore in an end portion of a motor commutator; and placing a ring varistor into the counter bore

A rotor assembly for a DC motor is provided which includes a rotor having a rotor shaft, a commutator mounted to the rotor shaft, and a varistor which is connected to the commutator via an electrically-conductive solderless fixing means, such as an electrically-conductive adhesive.