In one embodiment, a permanent magnet rotor is provided. The permanent magnet rotor includes at least one permanent magnet and a substantially cylindrical rotor core including an outer edge and an inner edge defining a central opening. The rotor core includes a radius R, at least one pole, and at least one radial aperture extending radially though the rotor core from the outer edge to a predetermined depth less than the radius. The at least one radial aperture is configured to receive the at least one permanent magnet. The rotor further includes at least one protrusion extending into the at least one radial aperture, the at least one protrusion positioned substantially along a bottom of the at least one radial aperture and configured to facilitate retention of the at least one permanent magnet within the at least one radial aperture.

A method for manufacturing an induction rotor includes placing a lamination stack into a fixture in which the first end of the lamination stack is rotated in an opposite rotational direction from the second end of the lamination stack to skew the conduction bars to an angle . Vertical members are fixed to an outer perimeter of each of the plurality of laminates of the lamination stack. Hoop members are fixed to each of the plurality of vertical members and an outer edge of each of the plurality of conduction bars. A conduction ring is fixed on each of the ends of the lamination stack. An outer perimeter of the lamination stack is machined to remove the plurality of vertical members and the plurality of hoop members from the lamination stack.

Rotors for electrical machines and methods of fabricating the same are disclosed. Electrical machine rotors may include a hollow non-magnetic shaft, an active region, and a plurality of coolant passages extending within the active region. The hollow non-magnetic shaft may extend along an axis and have an exterior surface that defines a shaft space extending along the axis. At least a portion of the active region may be disposed within the shaft space.

A method of forming a rotor lamination includes, with a laser, fabricating a first region of a lamination layer with a first powdered metal having a first composition. The first region at least partially defines a magnet pocket. The method further includes, with a laser, fabricating a second region of the lamination layer with a second powdered metal having a second composition different than the first composition. The second region is disposed immediately adjacent the first region.

A flywheel energy storage system incorporates various embodiments in design and processing to achieve a very high ratio of energy stored per unit cost. The system uses a high-strength steel rotor rotating in a vacuum envelope. The rotor has a geometry that ensures high yield strength throughout its cross-section using various low-cost quenched and tempered alloy steels. Low-cost is also achieved by forging the rotor in a single piece with integral shafts. A high energy density is achieved with adequate safety margins through a pre-conditioning treatment. The bearing and suspension system utilizes an electromagnet that off-loads the rotor allowing for the use of low-cost, conventional rolling contact bearings over an operating lifetime of several years.

A method of forming a rotor includes isolating a bridge area of an electrical steel lamination. The bridge area is disposed between a first portion of the electrical steel lamination and a second portion of the electrical steel lamination that is adjacent to the first portion. Each of the first portion, the second portion, and the bridge area has an initial hardness, and the electrical steel lamination has an initial magnetic permeability. After isolating, the method includes hardening only the bridge area so that the bridge area has a treated hardness that is greater than the initial hardness. Concurrent to hardening, the method includes decreasing the initial magnetic permeability at only the bridge area.

A method of manufacturing a rotor of an electric motor is disclosed. The method includes securing a plurality of permanent magnets to a sheet to form a magnet chain, bending the sheet to engage an inner surface of each permanent magnet with a curved outer surface of an insert mold, wrapping a metallic strip around an outer surface of the sheet to form a yoke of the rotor, and molding a polymeric material over the magnet chain and the yoke to form a cylindrical shell.

A manufacturing method for a rotor core included in a rotor of a motor punches an electromagnetic steel sheet includes punching a plurality of plates for rotor core from an electromagnetic steel sheet; producing a rotor-core precursor by stacking up the plates for rotor core; manufacturing a rotor core by annealing an outer circumferential region of the rotor-core precursor at a first predetermined temperature, and annealing an inner circumferential region of the rotor-core precursor at a second predetermined temperature; the first predetermined temperature being a temperature at which grain growth of crystals of the electromagnetic steel sheet is promoted; and the second predetermined temperature being a temperature at which grain growth of the crystals of the electromagnetic steel sheet is not promoted.

A manufacturing method comprising: a process S1 of forming a plate member which has a substantially annular scrap portion having a center hole through an axial direction and a core plate portion defining a portion of the core pieces arranged continuously with the scrap portion on a radially inner side of the scrap portion; a process S2 of forming a laminated body, which has the core pieces, by laminating the plate member; a process S3 of providing the laminated body and the shaft in a mold; a process S4 of forming a molding body by inserting a molten resin or a nonmagnetic material in the mold and forming the filling portion of which at least a portion is located between the core pieces; and a process S5 of separating the scrap portion and the core plate portion.

Provided is a motor including a stator and a rotor. The rotor includes a rotor core rotating integrally with an rotation shaft and having a core base end part fixed to the rotation shaft and core protrusions protruding outward in a radial direction from the core base end part; and a magnet disposed between the core protrusions adjacent to each other in a circumferential direction on an outer peripheral surface of the core base end part. A central position of the stator core in the axial direction, a central position of the rotor core in the axial direction, and a central position of the magnet in the axial direction are deviated from each other. The central position of the magnet in the axial direction is located between the central position of the stator core in the axial direction and the central position of the rotor core in the axial direction.