Abstract: A rotor of the present invention includes a rotor core, and a magnet press-fitted into a magnet insertion hole provided in the rotor core, the magnet has a hard magnetic body and a resin layer that is laminated on the hard magnetic body, that is disposed on an outward side of the rotor core in a radial direction and that includes a soft magnetic body, and the resin layer has a groove portion extending in a direction crossing an insertion direction.

Abstract: One embodiment of the present invention relates to a rotor and a motor having same, the rotor comprising: a rotor core; and a plurality of magnets arranged to be spaced apart from each other on an outer circumferential surface of the rotor core, wherein the rotor core includes: a body; and protrusions protruding obliquely inward at a predetermined angle from an inner circumferential surface of the body, wherein a predetermined gap (G1) is formed between the inner circumferential surface of the body and the end of each of the protrusions. Accordingly, the rotor and the motor having the same may minimize the amount of change in the outer circumferential surface of the rotor core by using the protrusions. As a result, it is possible to inhibit separation of the magnets attached to the outer circumferential surface of the rotor core.

Abstract: An electric motor comprising: a frame; and a stator assembly; the stator assembly including a bobbin assembly and at least one c-shaped stator core. The frame comprises at least one lug, the bobbin assembly includes at least one recess, and the stator assembly is fixed to the frame by fixing the lug inside the recess of the bobbin assembly.

Abstract: A rotor for a motor or for a radial flux electromagnetic generator having a cylindrical support housing a plurality of magnets (4), characterised in that the cylindrical support comprises a cylindrical mesh (5a) having mesh elements each defining a recess (5) for a respective individual magnet (4), each recess (5) having internal dimensions that are just sufficient to allow the introduction of a individual magnet (4) in its interior while leaving a space between the recess (5) and the individual magnet (4) filled by a fibre-reinforced resin, the mesh (5a) being made from a fibre-reinforced insulating material, the rotor comprising a non-conductive composite layer coating the individual magnets (4) and the mesh (5a).

Abstract: A motor includes a cover with first and second cup bodies. A flange portion of each of the first and second cup bodies includes first recesses recessed radially inward from an outer peripheral edge of the flange portion and evenly spaced apart in a circumferential direction of the flange portion, second recesses recessed radially inward from the outer peripheral edge of the flange portion, have a same circumferential width as that of the first recess, and are evenly spaced apart in the circumferential direction, a total number of the second recesses is the same as a total number of first recesses, and claw portions extending radially outward from a bottom surface of the corresponding second recess and have a circumferential width narrower than that of the second recess.

Abstract: An impeller 40 includes a disk 41 having a disk shape centered on an axis O, a plurality of blades 42 provided on a disk main surface 413 of the disk 41 facing a first side Dau in an axial direction Da at intervals in a circumferential direction around the axis O, and a cover 43 that covers the plurality of blades 42 from the first side Dau and gradually expands in diameter from the first side Dau toward a second side Dad in the axial direction. The cover 43 has a thick portion 49 at a position distant from a first end portion 431 positioned closest to the first side, the thick portion having a thickness greater than the thickness of the first end portion 431.

Abstract: A rotor assembly includes a shaft disposed along a central axis extending vertically, a tubular magnet disposed on a radially outer surface of the shaft, a lower spacer disposed axially below the magnet and fixed to the radially outer surface of the shaft, a shaft adhesive film attaching the shaft to the magnet, and a lower spacer adhesive film attaching an axially upper surface of the lower spacer to an axially lower surface of the magnet. The shaft adhesive film and the lower spacer adhesive film are an identical adhesive and are continuously formed.

Abstract: 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.

Abstract: Disclosed is a liquid cooling radiation system. The technical solution used by the present invention to solve the technical problem is: the liquid cooling radiation system comprises: a radiation device, comprising cooling pipes and a radiation structure device arranged on the cooling pipes; a pumping device, integrally arranged between the cooling pipes and generating power so that a coolant circulates within the cooling pipes; a heat absorption device, attached to a heating device and having a heat conduction effect with the heating device; a pipeline, used for connecting the radiation device and the heat absorption device. On the basis of existing products, the present invention utilises a solution wherein a liquid pump main body and a radiator are integrally arranged together. Thus, the radiation of a fan is used to take away heat on the radiator and heat generated by a pump power main body (i.e. a motor) itself is also taken away, thereby extending the service life of the motor.

Abstract: A rotor manufacturing apparatus 1 is provided, the rotor manufacturing apparatus 1 including: a first mold 2 and a second mold 3 respectively arranged on one end surface and another end surface in the axial direction of a cylindrical rotor core 40 in order to seal the magnet insertion hole 42 in the process of filling the gap between a permanent magnet 51 and a magnet insertion hole 42 with the resin material 52 and solidifying a resin material 52, in which each of the first mold 2 and the second mold 3 is provided with positioning protrusion parts 6a, 6b, 7a, and 7b that are protruded in the axial direction and are intended to position the permanent magnet 51 in a predetermined position with respect to the magnet insertion hole 42.

Abstract: A rotor for an electrical machine with one or a plurality of cooling ducts through which a cooling agent can flow. One end face of the rotor there is provided an annular space, bounded axially inwardly and radially outwardly and joined communicating with the cooling duct or ducts. A cover plate is provided, attached to the end face and bounding the annular space axially outwardly, having a central through-opening for introducing the cooling agent into the annular space.

Abstract: An inner-rotor type motor includes an iron core having a magnetic yoke portion and a plurality of magnetic pole portions. The magnetic yoke portion includes an assembly hole through which a shaft extends. A plurality of magnetic pole portions is arranged around the magnetic yoke portion. The iron core includes a plurality of receiving grooves. Each receiving groove is formed between two adjacent magnetic pole portions. The permanent magnets are received in the receiving grooves. At least one abutting member is coupled with an outer periphery of the shaft and includes a radial extension portion having a guiding surface. The guiding surface abuts against at least one of permanent magnets. The iron core, the permanent magnets, and the at least one abutting member of the rotor are received in a compartment of the stator. The shaft of the rotor is rotatably coupled to the stator.

Abstract: A semiconductor device includes a device main body that is semi-annular, the device main body having an inner circumferential surface formed arcuate in plan view and an outer circumferential surface formed arcuate in plan view. Cutout portions are formed on a first end surface, on one end side, in a circumferential direction, of the device main body and a second end surface, on an other end side, in the circumferential direction, of the device main body. The cutout portions are used for inserting screws for fixing the device main body to a base portion.

Abstract: The external rotor for an electric machine includes a cylindrically shaped receptacle having a peripheral wall and a magnet-receiving assembly including segments assembled to the inner surface of the peripheral wall so as to define a cylindrically shaped stack. The segments are shaped so as to yield magnet-receiving portions in the ring-shaped stack, and permanent magnets are secured to the magnet-receiving portion of the magnet receiving assembly.

Abstract: A synchronous motor is driven by three phase alternate current. The rotor core includes a laminated body configured by laminating plate members made of electrical steel sheet. Each plate member is formed in a substantially circular shape in a plan view and formed with projections along an outer circumference thereof. The number of slots of the stator is 3xy when variable x is a natural number and variable y is a positive odd number. The number of poles of the rotor is (3y+1)x or (3y?1)x. The number of projections of each plate member is a common measure of (3y+1)x and (3y?1)x. The laminated body has a structure in which the plate members are laminated so that the projections are shifted relative to one another.

Abstract: Provided is a rotor member that can contribute to an easy assembling operation and components thereof can be reused. The rotor member includes a magnet mounting member having a first end and a second end, a plurality of magnets arranged radially outwardly of the magnet mounting member, and a tubular holding member arranged radially outwardly of the plurality of magnets and holds the magnets between the holding member and the magnet mounting member. The magnet mounting member includes a slit that radially penetrates the magnet mounting member and extends in a predetermined axial-direction section.

Abstract: A rotor of an electric motor includes a laminated armature core, a shaft, magnets arranged on the circumference of the laminated armature core, and a plastic overmold. The laminated armature core has at least one associated channel on the circumference of the laminated armature core for each magnet. The channels extend parallel to the shaft, and the laminated armature core has radially oriented webs on the circumference. The webs (8) extend parallel to the shaft and a magnet (9) is arranged between each pair of webs (8), and the plastic overmold (4) encloses the laminated armature core (1) and the magnets (3) to such an extent that only the radial outer face of the magnets (3) is free of plastic (4).

Abstract: The present invention relates to a motor for a vehicle and a rotor applied to the motor, and the rotor may include a rotor housing including a magnet mounting portion; a magnet inserted in the magnet mounting portion; and a ferromagnetic bonding layer which fills between the magnet mounting portion and the magnet.

Abstract: In a permanent magnet motor, projections each include a second projecting portion and a first projecting portion separated away from a side surface of a permanent magnet. When the first projecting portion has a total length L1 in an axial line direction and a height t1, and when the second projecting portion has a total length L2 in the axial line direction and a height t2, (L1×t1)>(L2×t2) is satisfied. As a result, the permanent magnet motor capable of reducing vibration noise of the motor by reducing irregular rotation, reducing decrease in motor torque, and further reducing increase in motor physical size can be obtained.

Abstract: An electric motor of a vehicle component, in particular a window opener drive or seat adjuster drive, includes a rotor, a stator with a three-phase stator winding having at least one coil per phase with first and second coil ends, and a connection element having a number of vias corresponding to the number of coil ends, the vias forming first and second contacting groups. The vias of the first contacting group are paired with a contact ring with contact points for electrically conductively connecting the first coil ends, in particular while forming a neutral point. The second coil ends are guided through the vias of the second contacting group, and a coil end portion or additional conductor element of the coil ends is azimuthally guided along the connection element and guided, preferably axially, out of the connection element while providing a three-phase winding connection at exposed positions.

Abstract: Disclosed is an anti-separating structure of a sensing magnet for EPS motor, the structure being a coupling structure between the sensing magnet and a plate of the EPS motor, the structure including a disk-shaped plate formed with a magnet accommodation unit protrusively formed near at a rotation shaft, a ring-shaped sensing magnet centrally formed with a through hole having a diameter corresponding to the magnet accommodation unit, and magnet grip units each formed at a predetermined gap along a circumferential surface of the magnet accommodation unit.

Abstract: 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.

Abstract: A number of variations may include a product comprising a magnet holder for a rotor lamination comprising: a first portion, a second portion, and a third portion, wherein the first and second portions are linear and constructed and arranged to hold a magnet and wherein the third portion extends outward from approximately a center location between the first and the second portions, and wherein the third portion is constructed and arranged to carry a load from a centrifugal force of the magnet.

Abstract: A rotor of an electrical rotating machine includes a first rotor core, a second rotor core which overlaps the first rotor core in an axial direction, a non-magnetic substance layer which is interposed between the rotor cores, and a plurality of permanent magnet portions which are embedded in each rotor core. Each of the rotor cores includes a plurality of flux barrier portions and a plurality of effectual magnetic flux portions which are alternately arranged on an outer circumferential surface thereof. The flux barrier portion of the first rotor core overlaps both of a portion of the flux barrier portion of the second rotor core and a portion of the effectual magnetic flux portion of the second rotor core in the axial direction such that, in the adjacent rotor cores, the effectual magnetic flux portions do not overlap each other in the axial direction.

Abstract: Certain aspects relate to topologies for an interior permanent magnet (IPM) electrical machine having increased saliency torque, increased flux-linkage, reduced magnet leakage flux, and reduced detrimental slotting effects compared to existing IPM electrical machines. The IPM electrical machine includes a rotor having a number of poles and a flux barrier formed along the edge of the rotor between poles. The flux barrier contains a magnet or set of magnets having a varying thickness, with a central thickest portion located along the d-axis of the rotor. A magnet retention structure, which may be formed integrally with the rotor or provided as a separate structure, surrounds the rotor and magnets. The rotor and magnets combine to form a smooth circular profile having no air gaps.

Abstract: An interior permanent magnet synchronous motor includes a stator a rotor disposed with a space between the stator and the rotor, and a plurality of permanent magnets embedded in the rotor. In particular, a plurality of slits are formed in one side surface of the permanent magnet in a rotation direction of the rotor at equal intervals.

Abstract: A method for bonding a plurality of Nd—Fe—B permanent magnets includes a step of curing the layer of insulating adhesive at an initial temperature of between 20° C. and 250° C. and between 0.1 hr and 24 hr prior to the step of sandwiching. A predetermined clamping pressure of between 0.1 MPa and 10 MPa is then applied to the Nd—Fe—B permanent magnets. The stacked Nd—Fe—B permanent magnet is cured at a predetermined temperature of between 150° C. and 350° C. and between 0.1 hr and 12 hr. A clamping tool apparatus includes at least one of three intermediate guides disposed on the lower plate, in the chamber, spaced from the magnet positioning members, and extends to a proximal end defining a second predetermined distance with the second predetermined distance being less than the first predetermined distance of the magnet positioning members. The upper plate defines a plurality of apertures for receiving the magnet positioning members and the intermediate guides.

Abstract: A rotor of a motor includes first and second rotor cores, a field magnet, and a commutator magnet. The first and second rotor cores each include a core base and a plurality of claw poles. The claw poles of the first rotor core and the claw poles of the second rotor core are alternately arranged in a circumferential direction. The field magnet is located between the core bases. The field magnet is magnetized in an axial direction so that the claw poles of the first rotor core and the claw poles of the second rotor core function as different magnetic poles in the circumferential direction. The commutator magnet is located on an outer circumference of the field magnet around the claw poles. The commutator magnet is magnetized so that surfaces having the same polarity face each other between the claw poles and the commutator magnet.

Abstract: A rotor includes a first rotor core, a second rotor core, a first magnet, a second magnet, and an annular magnet. The first magnet is arranged between first extensions of the first rotor core. The annular magnet, which is arranged between second extensions of the second rotor core, is held between the first core base and the second core base. The first magnet and the second magnet are formed integrally.

Abstract: A power tool includes a housing and a brushless motor, the brushless motor having a stator and a rotor inside the housing, the rotor including a rotor core having a plurality of axially extending through holes and a permanent magnet in each of the plurality of through holes. The rotor is provided with at least one positioning structure by which the rotor core can be held in a desired circumferential orientation while the permanent magnets are inserted into the through holes.

Abstract: Provided is a rotor for a rotating electrical machine which is capable of minimizing increases in eddy current losses via a magnet, while making insulating film processing of the surface of the magnet unnecessary. The rotor for the rotating electrical machine includes: a rotor core having a magnet insertion hole extending inside; a magnet inserted in the magnet insertion hole; and an insulating filler which is filled between the inner wall of the magnet insertion hole and the magnet so as to secure the magnet. The magnet is secured by the filler in such a manner that the surface of the magnet inside the magnet insertion hole is in an inclined position with respect to the extending direction of the inner wall of the magnet insertion hole.

Abstract: An electric motor includes: a ring-shaped stator including a field coil; and a rotor holding a permanent magnet in a magnet holding portion on an outer circumference thereof in an exposed state and being supported to be rotatable about a rotary shaft core in an inner space of the stator, wherein the magnet holding portion is configured to have a magnet insertion portion and a pair of regulation bodies, and the permanent magnet is configured to include a cylindrical outer wall surface, a rear wall surface, a pair of side wall surfaces, and a pair of engaged surfaces.

Abstract: An apparatus according to one embodiment includes a motor having: a rotor, a magnet, and a damping layer positioned between the rotor and the magnet. The damping layer is constructed of a material characterized by converting kinetic energy into heat.

Abstract: A rotor assembly for a permanent magnet electric machine includes a plurality of rotor laminations joined to form a rotor body. Each of the plurality of rotor laminations includes a plurality of slots. One or more permanent magnets are mounted within respective ones of the plurality of slots. Each of the one or more permanent magnets includes a thermal enhancement bonding coating. A method of forming a rotor assembly is also disclosed.

Abstract: A brushless motor may comprise a rotor comprising a shaft, a back yoke fixed on the shaft, a permanent magnet disposed at an outer circumference of the back yoke and first and second resin portions. The first resin portion may be formed at one ends of the back yoke and the permanent magnet and the second resin portion may be formed at other ends. The first and second resin portions may be fixed the back yoke and the permanent magnet. A communication hole communicating one end side and another end side in the shaft axis direction may be formed through the back yoke or between the shaft and the back yoke. A third resin portion connecting with the first and the second resin portions may be formed within the communication hole. The first, second and third resin portions may be formed integrally.

Abstract: A rotor (11) with a squirrel cage and permanent magnets (19) mounted on and distributed around the circumference of the rotor, including a core stack extending over the entire rotor region with longitudinally continuous rotor slots extending over the length of the core stack. The squirrel cage is constructed with cage bars disposed, and preferably cast, in the rotor slots; short circuit rings connect the cage bars at both end faces of the core; and the radius of the rotor region is reduced by at least the radial thickness of the magnets. The radius of rotor (11) is reduced over the entire length between short circuit rings (17) such that the radial height of cage bars (15, 29) or cage webs (27) connected thereto is reduced. Also an electric motor or a radial pump having such a rotor, and methods of producing or operating such devices.

Abstract: A field structure of an electrical machine includes a plurality of field slots. Each field slot extends from a first surface of the field structure into the body of the field structure. Each filed slot also has a T-shaped cross-sectional area dimensioned to accommodate a magnet pole assembly comprising a corresponding cross-sectional area.

Abstract: A rotor-fixing resin composition of the present invention comprising: an epoxy resin-containing thermosetting resin; a curing agent; and an inorganic filler, wherein a tensile elongation at break-a is 0.1% or higher and 1.7% or lower, the tensile elongation at break-a is obtained by subjecting a test piece to a tensile test pursuant to JIS K7162 under conditions of a temperature of 120° C., a test force of 20 MPa and 100 hours, and the test piece is a cured product produced by subjecting the rotor-fixing resin composition to curing by heating at 175° C. for 4 hours, and molding to a dumbbell shape pursuant to JIS K7162.

Abstract: A rotor for a rotating electric machine includes a rotor core including a plurality of laminated steel plates; a permanent magnet fixed to an outer peripheral surface of the rotor core, the permanent magnet having a length in an axial direction less than that of the rotor core; and an adhesive member disposed on a region of the outer peripheral surface of the rotor core between an end of the permanent magnet in the axial direction and an end of the rotor core in the axial direction.

Abstract: A rotor having permanent magnets 10 includes: a laminated core body 13 having a shaft hole 12 in the center thereof and magnet insertion holes 15 around the shaft hole 12; permanent magnets 16 disposed in the respective magnet insertion holes 15; and first and second end face plates 18, 19 disposed on one axial end and the other axial end of the laminated core body 13, respectively, the first and second end face plates 18, 19 including first and second through holes 32, 33, respectively. The first and second through holes 32, 33 each overlap a contour of a magnet insertion hole 15 on a radially inner side or a radially outer side in a plan view, and have first and second tapered portions 34, 35 gradually expanding the diameter toward the magnet insertion hole 15, respectively.

Abstract: A rotor core assembly that includes a magnet, a first end cap located at an end of the magnet, a second end cap located at an opposite end of the magnet, and a sleeve that surrounds the magnet and the end caps. The sleeve forms an interference fit with each of the end caps, and an adhesive is located between the magnet and the sleeve. Additionally, a method of manufacturing the rotor core assembly.

Abstract: A laminated core of a rotor includes an inner core portion and a plurality of outer core portions. The inner core portion axially extends in a cylindrical shape in a region located more radially inward than magnets. The outer core portions are arranged in a circumferential direction in a region located more radially outward than the inner core portion. The plurality of outer core portions and a plurality of the magnets are alternately arranged in the circumferential direction. Accordingly, magnetic flux generated from a pair of magnetic pole surfaces of the plurality of magnets can be effectively used. In addition, the laminated core includes caulking portions in each of the inner core portion and the plurality of outer core portions. Accordingly, a plurality of thin plate cores are firmly fixed.

Abstract: A motor apparatus having a high efficiency and reducing manufacturing cost by using a cost effective ferrite permanent magnet includes a rotatable shaft, a fan connected to one side of the shaft to generate a flow of air, a stator including stator cores arranged in a circumferential direction, and a coil wound around the stator core, and a rotor disposed at an inside of the stator and provided in a form of a cylinder having a passage allowing the shaft to pass through the rotor includes a rotor core provided with a protrusion structure and one or more ferrite magnets coupled to the rotor core to provide a magnetic force. By using a ferrite magnet, when compared to a conventional universal motor, a superior efficiency is obtained, and when compared to a BLDC motor using a Nd magnet, a low cost BLDC motor is implemented.

Abstract: An interior permanent magnet motor in provided which is made up of a permanent magnet, and a rotor core of which an insertion aperture for the permanent magnet to be inserted thereinto is formed in the rotor core. Additionally, the interior permanent magnet motor includes a first end plate which is connected to the rotor core and of which a first seating portion for the permanent magnet is disposed thereto is formed in the first seating portion and a second end plate which is connected to the rotor core and of which a second seating portion for the permanent magnet is disposed thereto is formed in the second end plate.

Abstract: A rotating electrical machine comprises a stator and a rotor. The rotor includes a rotor iron core in which a permanent magnet is disposed. The rotor iron core comprises a connection part, a plurality of magnetic pole part, a first gap, and a second gap for injection of the adhesive. The connection part is configured to surround a rotational axis. The plurality of magnetic pole parts are provided in an outer portion than the connection part in a radial direction. The first gap is configured to penetrate along an axial direction between the magnetic pole parts in an outer portion than the connection part in the radial direction and in which the permanent magnet is fixed with adhesive. At least one of the second gaps is provided for each of the first gaps in communication with the first gap.

Abstract: A rotating electric machine includes a stator and a rotor. The rotor includes an iron core and permanent magnets. The iron core includes a cylindrical connection portion and ten magnetic pole portions. The cylindrical connection portion surrounds a rotation shaft. The ten magnetic pole portions, the number of which corresponding to the number of poles, are disposed radially outside the connection portion. The connection portion and the magnetic pole portions are integrated with each other. The permanent magnets are disposed between the magnetic pole portions. The magnetic pole portions include flange portions that cover parts of radially outer surfaces of the permanent magnets while allowing at least parts of the radially outer surfaces to be exposed. Each of the permanent magnets includes a tapered portion in at least a part thereof, and the tapered portion has a length in a direction perpendicular to the radial direction that decreases radially inward.

Abstract: A magnet rotor assembly comprises a magnet sleeve held on a rotor shaft by a rigid adhesive layer that includes at least one axial wedge shape corresponding to an axial irregularity on at least one of the surfaces bonded by the adhesive layer. Improved crush strength in the magnet sleeve and in other bonded metal parts, both initially and after exposure to high temperatures is accomplished by impregnating the parts with a curable resin.

Abstract: The invention relates to methods for manufacturing a rotor (14) for an electric machine (13), having the following method steps: a) manufacturing a magnetic element (8) by bonding permanent magnets (1, 1?, 1?, 1??) by means of a first adhesive, each permanent magnet (1, 1?, 1?, 1??) having a side with a magnetic North pole (N) and a side with a magnetic South pole (S), the permanent magnets (1, 1?, 1?, 1??) being arranged during bonding such that the sides of the magnetic North poles (N) or the sides of the magnetic South poles (S) form a common underside (3, 3?, 3?, 3??) of the magnetic elements (8), the first adhesive having a hard consistency in the cured state; and b) bonding the underside of the magnetic element (8) to a yoke (12) by means of a second adhesive, the second adhesive being soft and elastic in the cured state. Furthermore, the invention relates to an associated rotor.

Abstract: The hole diameter of a shaft through hole formed in the rotor core is changed in the axial direction, thereby forming a concave portion whose hole diameter is large and a convex portion whose hole diameter is small in the inner circumferential surface of the shaft through hole; the convex portion is arranged at opening portions on both ends of the shaft through hole; a shaft having ridge-shaped convex portions on a press-fitting portion is press-fitted into the shaft through hole to assemble; the number of points of the concave portion is equal to or more than two; and respective diameter dimensions of the concave portion, the convex portion, and the shaft are set to be the diameter of a main body of the shaft<the diameter of the convex portion<the diameter of ridge-shaped convex portions of the shaft<the diameter of the concave portion.

Abstract: In order to provide a motor rotor in which a permanent magnet is prevented from corroding, wherein a motor rotor for use in a motor for driving a pump rotor rotating shaft of a vacuum pump is provided which comprises a rotor core made up of a plurality of steel plates which are laminated in an axial direction and having a through hole, a permanent magnet which is disposed in the through hole, and end plates which are attached individually to axial end portions of the rotor core, wherein an adhesive is applied to a whole surface of each of the plurality of steel plates, and the plurality of steel plates are surface joined to each other and to the end plates via the adhesive.