The invention relates to a process for manufacturing a waterproof magneto-rotor (1) made of rare-earth elements, to be used in a synchronous electric motor having a rotor (2) with a permanent magnet and wherein the rotor (2) is solidly fixed to a shaft (3). The process comprises the following phases: a first phase of coating the rotor (2) with a first inner protective layer (12) obtained by a first injection moulding phase; a second phase of coating the first inner protective layer (12) of the rotor (2) with a second outer protective layer (14) obtained by a second injection moulding phase; at least one annular protective barrier (15) being shaped on at least one or both the opposed end surfaces of the rotor (2) during the first injection moulding phase, for preventing water or humidity from seeping between the first inner protective layer (12) and the second outer protective layer (14).

A rotor includes a plurality of permanent magnets inclined relative to the axial direction of a rotor core. A method for manufacturing the rotor includes producing each of the permanent magnets, and providing the permanent magnets on the outer periphery of the rotor core. The producing of each of the permanent magnets includes working a magnet block into a shape such that a first surface and a second surface have a parallelogram shape, a third surface and a fourth surface are parallel to each other, and a fifth surface and a sixth surface extend planarly from the third surface to the fourth surface. The providing of the permanent magnets includes arranging the permanent magnets so that, between the permanent magnets adjacent to each other, the fifth surface and the sixth surface face each other.

A manufacturing method of an iron core product includes: heating an iron core body attached to a jig together with the jig; removing the iron core body from the jig when the jig and the iron core body are heated to denote a first temperature; and separately cooling, after removing the iron core body from the jig, the iron core body and the jig such that the iron core body is at a second temperature lower than the first temperature and the jig is at a third temperature lower than the first temperature.

A method of manufacturing a rotational electric machine rotor includes: forming a rotor shaft having a non-circular sectional outer shape; forming a rotor core by stacking a predetermined number of magnetic body thin plates each including a center hole having a non-circular shape corresponding to the non-circular sectional outer shape of the rotor shaft; and forming a protruding part for fixing the rotor core and the rotor shaft to each other by inserting the rotor shaft into the non-circular center hole of the rotor core and squashing the rotor shaft extending out of an axial-direction end face of the rotor core by using a predetermined swaging jig to expand the rotor shaft outward beyond an outer periphery of the non-circular section along the axial-direction end face of the rotor core.

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.

Provided are a motor with which dynamic unbalance of a rotor can be suppressed, and a deterioration in the motor characteristics can be reduced, and a method for manufacturing said motor. In a motor unit: a rotor central position, a magnet central position, and a stator central position are offset from one another; a length L1 between inner wall surfaces, facing one another in an axial direction, of magnet holders, an axial direction magnet length L2 of magnets, and an offset length L3 satisfy L1L2<L3; and first and second holder lengths Lh are the same.

An apparatus for assembling a permanent magnet motor rotor includes a first-end positioning assembly, a plurality of connectors, and a second-end positioning assembly. The first-end positioning assembly is utilized to fix a first-end rotor core. The second-end positioning assembly is utilized to fix a second-end rotor core. The connectors are utilized to connect and fix the first-end positioning assembly with the second-end positioning assembly. Each first longitudinal axis of each first positioning element of the first end positioning assembly is different from each second longitudinal axis of each second positioning element of the second end positioning assembly. In addition, a method for assembling a permanent magnet motor rotor is also provided.

A method of manufacturing a rotating body includes disposing an end plate on an end surface of the core body in a height direction, and forming the rotating body by welding the end plate and the core body together. The rotating body is formed by welding the end plate and the core body together while a temperature of the core body and the end plate is within a predetermined operational a temperature range associated with rotation of the rotating body in a manufactured state of operation.

A method of manufacturing a core product includes injecting molten resin into a resin injection portion provided in a core body so as to extend in a longitudinal direction of the core body, and forming a core product by welding the core body. A buffer region is set between the resin injection portion and a periphery of the core body in a lateral direction of the core body. The core product is formed by welding the core body so that a weld bead formed on the core body is prohibited from reaching the buffer region, and so that the weld bead is spaced apart from the resin injection portion in the lateral direction of the core body.

A method of balancing a rotor and/or fixing rotor components includes arranging a plurality of generally like laminations side by side in a stack to form at least a part of a rotor. The rotor has a rotational center axis and each of the laminations having a plurality of apertures that cooperate to form passages that extend axially along a length of the stack. In accordance with an aspect of the method, a polymer based fixation material is filled in the passages in a manner to fix the laminations together in the stack. With the fixation material, a sprue is formed, projecting from an axial face of the stack. In accordance with another aspect of the method, a weight of the sprue is adjusted to rotationally balance the rotor about the rotor center axis.