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.

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 stacked core includes a plurality of core pieces that are arranged in a stack. Each of the core pieces has a plurality of magnet insertion holes. A bridge is provided between a radially-outer end of each of the magnet insertion holes and an outer region of each of the core pieces, A radially-outer contour of the bridge is provided on a radially-inner side of a blanking-contour line of each of the core pieces.

In the rotor of the present invention, each magnet has an inward part adjoining the rotor core and an outward part positioned outward of the inward part in a radial direction of the rotor core. The outward has a facing surface which faces a stator and a pair of side surfaces which extend from two end parts of the facing surface in a circumferential direction toward the inward part. The inward part has a pair of overhanging parts which overhangs outward in the circumferential direction with respect to the pair of side surfaces of the outward part. Each locking projection of the rotor core passes between overhanging parts of two adjoining magnets and projects outward in the radial direction to engage with the overhanging parts.

A solid fixing resin composition, which has excellent filling properties, and a rotor using the same are provided. The fixing resin composition is used to form a fixing member constituting a rotor which includes a rotor core (110) which has a laminate formed by lamination of a plurality of plate members, is fixed and installed on a rotating shaft, and has a plurality of hole portions (150) arranged along the peripheral portion of the rotating shaft, provided in the laminate; a magnet (120) inserted in the hole portion (150); and a fixing member (130) formed by curing a fixing resin composition, filled in the separation portion between the hole portion (150) and the magnet (120), the resin composition including a thermosetting resin (A) containing an epoxy resin; a curing agent (B); and an inorganic filler (C), in which the ICI viscosity at 150 C. of the epoxy resin is equal to or less than 3 poises.

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.

Disclosed herein is a rotor for motor including a rotor tube disposed inside a stator, a rotor core that is formed on a circumferential surface of the rotor tube and integrally formed with the rotor tube, and magnets coupled to the rotor core. The rotor for motor provides an advantageous effect of preventing the deformation of the rotor tube in the process of assembling the rotor tube and the rotor core.

In a method for manufacturing an interior permanent magnet rotor unit, a radial magnetizing part including high magnetic permeability portions and low magnetic permeability portions face a core, and a magnetic field of axial magnetizing parts is applied to the radial magnetizing part in an axial direction of the radial magnetizing part. This causes the magnetic field to enter the core via the radial magnetizing part and cross magnet materials filling insertion holes of the core.

A separation catch mechanism disposed above a power section of a motor prevents full separation of lower components of the motor from upper components and an attached drillstring. An extension of the mechanism has a first end coupled to the rotor and has a second end disposed in a housing member beyond a seat. An expandable shoulder, such as a washer, disposed on the second end of the extension can be expanded thereon to engage the seat should housing components separate from one another on the motor. To expand the washer after being inserted during assembly past the seat, the second end of the extension has a tapered head on which the washer is disposed. The outside diameter of the washer is expanded on the tapered head by tightening a nut against the washer.

Generator rotor comprising a rotor rim and a plurality of permanent magnet modules and a plurality of anchors arranged at an outer or inner circumference of the rotor rim such that the anchors substantially fix the permanent magnet modules to the rotor, wherein the permanent magnet modules comprise a base having a bottom surface, two axially extending side surfaces and a top surface, and one or more rows of magnets mounted on said top surface, wherein the two side surfaces of the permanent magnet modules each comprise an axially extending groove, and wherein the anchors have a shape that substantially fits exactly in axially extending grooves of neighboring permanent magnet modules.