A bobbin structure of an armature of a three-phase motor having 6N (N is a natural number) slots and 3N coils per phase, the bobbin structure including: a main pole into which a winding bobbin around which a coil is wound is inserted; and an auxiliary pole into which an empty bobbin around which the coil is not wound is inserted. The main pole and the auxiliary pole are placed in a circumferential direction with respect to a rotation axis, and a contact portion where the empty bobbin and the winding bobbin are in contact with each other is formed on each of an outer peripheral side and an inner peripheral side of the slot formed between the main pole and the auxiliary pole.

A bobbin structure of an armature of a three-phase motor having 6N (N is a natural number) slots and 3N coils per phase, the bobbin structure including: a main pole into which a winding bobbin around which a coil is wound is inserted; and an auxiliary pole into which an empty bobbin around which the coil is not wound is inserted. The main pole and the auxiliary pole are placed in a circumferential direction with respect to a rotation axis, and a contact portion where the empty bobbin and the winding bobbin are in contact with each other is formed on each of an outer peripheral side and an inner peripheral side of the slot formed between the main pole and the auxiliary pole.

A method of manufacturing a rotor of an electric motor or an electric generator includes positioning a plurality of amortisseur bars and using additive manufacturing to place electrically conductive material. More specifically, positioning the amortisseur bars may include circumferentially positioning the bars around a rotor stack and using additive manufacturing to place electrically conductive material may include forming a non-solid pattern of electrically conductive material, such as a pattern of electrically conductive traces, across opposite axial ends of the rotor stack to electrically interconnect an amortisseur circuit.

A method of manufacturing a rotor of an electric motor or an electric generator includes positioning a plurality of amortisseur bars and using additive manufacturing to place electrically conductive material. More specifically, positioning the amortisseur bars may include circumferentially positioning the bars around a rotor stack and using additive manufacturing to place electrically conductive material may include forming a non-solid pattern of electrically conductive material, such as a pattern of electrically conductive traces, across opposite axial ends of the rotor stack to electrically interconnect an amortisseur circuit.

A stator for an electric machine includes a generally cylindrical stator core having a plurality of circumferentially-spaced and axially-extending core teeth that define a plurality of circumferentially-spaced and axially-extending core slots in a surface thereof, a main winding having a plurality of coils, each of the coils including a plurality of turns occupying the plurality of slots in the stator core, and a tertiary excitation winding having a plurality of coils, each of the coils including a single turn occupying at least a subset of the plurality of slots in the stator core. The coils of the main winding are unevenly arranged in the plurality of slots.

BLDC motor including a stator with teeth which extend toward an inner side of a core and have a coil wound therearound; rotors disposed at an inner side of the stator and spaced apart from each other having a plurality of permanent magnets coupled to a core thereof; and hall sensors disposed and spaced apart to be opposite to an outer circumferential surface of the core of the rotor and disposed within a height range between both surfaces in a height direction of the core of the rotor to detect a change in a magnetic field in response to a rotation of the rotor, thereby accurately grasping positional information of a rotor and accurately controlling a rotation of the rotor by transmitting a magnetic flux generated from a permanent magnet of the rotor to a hall sensor enabling the hall sensor to detect a change in a magnetic field.

BLDC motor including a stator with teeth which extend toward an inner side of a core and have a coil wound therearound; rotors disposed at an inner side of the stator and spaced apart from each other having a plurality of permanent magnets coupled to a core thereof; and hall sensors disposed and spaced apart to be opposite to an outer circumferential surface of the core of the rotor and disposed within a height range between both surfaces in a height direction of the core of the rotor to detect a change in a magnetic field in response to a rotation of the rotor, thereby accurately grasping positional information of a rotor and accurately controlling a rotation of the rotor by transmitting a magnetic flux generated from a permanent magnet of the rotor to a hall sensor enabling the hall sensor to detect a change in a magnetic field.

A rotor bar fault in a rotor of an electrical machine having a plurality of rotor bars and an end ring configured to short circuit the rotor bars. The method includes the steps of measuring a first temperature at a first end ring location, and measuring a second temperature at a second end ring location, the second end ring location being different from the first end ring location. As broken rotor bars cause a non-uniform temperature distribution in the end ring, the detection of rotor bar faults can be based on monitored temperatures at different end ring locations.

A rotor bar fault in a rotor of an electrical machine having a plurality of rotor bars and an end ring configured to short circuit the rotor bars. The method includes the steps of measuring a first temperature at a first end ring location, and measuring a second temperature at a second end ring location, the second end ring location being different from the first end ring location. As broken rotor bars cause a non-uniform temperature distribution in the end ring, the detection of rotor bar faults can be based on monitored temperatures at different end ring locations.

A lamination for use in an integrated drive generator is formed from a plurality of plates having a body including a pair of opposed cylindrical surfaces. Non-cylindrical ditches are defined circumferentially intermediate the pair of cylindrical surfaces. A plurality of passages are formed in an outer periphery of the cylindrical surfaces including relatively large holes extending through a slot to the outer periphery. Grooves are formed intermediate the relatively large holes.