Rotor core utilizing laminations having slots with dual direction skew portions
AssigneeGeneral Electric Company
InventorsDaniel M. Saban, Charles Michael Stephens, Gerald Burt Kliman
Life of this patent
Estimating the term…
Abstract
Divided magnet rotors R having a stepped skew rather than a helical skew are described. The stepped skew enables the use of straight magnet sections (44) that can be inserted into the rotor core notches (38) thereby eliminating the need to produce a helix from the rotor cage. The stepped skew is effective in decoupling stator slot order harmonics. In addition, the stepped skew rotor R includes, in some embodiments, open slots (22) so that the rotor is not subject to rotor bridge saturation.
Claims26
A rotor comprising a plurality of rotor laminations, each set of said laminations having an outer periphery, a first set of rotor laminations comprising a plurality of slots having skew portions extending in a first direction, a second set of said rotor laminations comprising a plurality of slots having skew portions extending in a second direction, and a plurality of notches having an open end at said outer periphery and substantially aligned radially and coextensive radially with at least one of said skew portions, wherein at least one of said notches is occupied by a metal.
A rotor for an electric motor, said rotor comprising:
- a rotor core comprising a plurality of rotor laminations, each of said laminations having an outer periphery, a first set of rotor laminations comprising a plurality of slots having skew portions extending in a first direction, a second set of said rotor laminations comprising a plurality of slots having skew portions extending in a second direction, a plurality of notches having an open end at said outer periphery and substantially aligned radially and coextensive radially with at least one said skew portions, and a central rotor shaft opening, wherein at least one of said notches is occupied by a metal and remaining of said notches arc occupied by at least one permanent magnet;
- a rotor shaft having an axis which is coaxial with a rotor core axis of rotation and extending through said central rotor shaft opening;
- and
- a plurality of secondary conductors extending through said slots.
An electric motor, comprising:
- a stator comprising a stator core, first and second main windings, said first main winding configured to form a lower number of poles than said second main winding, said stator core forming a stator bore;
- and
- a rotor core comprising a plurality of rotor laminations, each of said laminations having an outer periphery, a first set of rotor laminations comprising a plurality of slots having skew portions extending in a first direction, a second set of rotor laminations comprising a plurality of slots having skew portions extending in a second direction, a plurality of notches having an open end at said outer periphery and substantially aligned radially and coextensive radially with at least one of said skew portions, a plurality of secondary conductors extending through said slots, wherein at least one of said notches are occupied by a metal and remaining of said notches are occupied by at least one permanent magnet, wherein the at least one permanent magnet is magnetized to form a number of poles equal to the number of poles formed by said second main winding.
Dependencies are inferred from the claim text.