Abstract: Rotor formed by groups of materials (4) that orientate the magnetic field and magnets (2) in spiral lines, with the two magnetic poles of each magnet (2) facing the stator (3). Close to a magnetic pole of the end of the group, the material (4) that orientates the magnetic field protrudes towards the stator (3). This configuration enables to vary the field of each magnetic pole of the rotor which is projected to the stator; in this way, one end of the group of magnets (2) concentrates a very close magnetic pole in order to interact with the stator (3) and the opposite magnetic pole moves away gradually in order to decrease the interaction with the stator (3). The application is for magnetic motors.

Abstract: In a radial-direction gap type magnet motor, when an energy density increases, a direction change M?/?p of a static magnetic field with respect to a mechanic angle between different poles increases in an exponential manner and thus to decrease a cogging torque of the motor is not compatible to increase a torque density. In order to solve the problem, assuming that ?t denotes a mechanic angle of a stator iron core teeth, ?p denotes a mechanical angle of a magnetic pole, and M? denotes an angle of a static magnetic field with respect to a circumferential tangential line of a radial magnetic pole center, a radial-direction type magnet motor in which ?t<?p, M? in a magnetic pole center region is 75 to 90°, and M?/?p?7 is satisfied in the magnetic pole end region of ?p×0.1°, and further, a static magnetic field generating source is configured as a magnetic anisotropic magnetic pole having an energy density (BH) max?150 kJ/m3 is provided.

Abstract: An object of the present invention is to provide a permanent-magnet-type rotating electrical machine capable of realizing a variable-speed operation at high output in a wide range from low speed to high speed and improving efficiency and reliability. The permanent-magnet-type rotating electrical machine of the present invention includes a stator provided with a coil and a rotor in which there are arranged a low-coercive-force permanent magnet whose coercive force is of such a level that a magnetic field created by a current of the stator coil may irreversibly change the flux density of the magnet and a high-coercive-force permanent magnet whose coercive force is equal to or larger than twice that of the low-coercive-force permanent magnet.

Abstract: A surface magnet type rotor and an inner magnet type rotor having good motor characteristics in which bonding strength is high between a magnet section and a soft magnetic yoke section, and structural reliability is high even in high speed use, and its producing method. The rotor comprises an anisotropic bond magnet section and a soft magnetic section wherein the anisotropic bond magnet section is preformed in magnetic field and then formed to be integrated with the soft magnetic section in nonmagnetic field. Subsequently, it is heat hardened to produce a surface magnet type rotor. Magnet units, each having a magnetic pole composed by bonding a pair of permanent magnets such that the directions of magnetization become symmetric with respect to the bonding surface, are linked such that magnetic poles of different polarities appear alternately on the magnetic action surface thus forming an anisotropic magnet body.

Abstract: The axial gap motor includes the rotor having: a rotor frame including a plurality of ribs extending in a radial direction, an inner circumferential side annular shaft, and an outer circumferential side annular rim, which are integrally coupled to each other through the ribs; the shaft has shaft side rib mounting holes through which the ribs are mounted, the rim has rim side rib mounting holes through which the ribs are mounted, the ribs have radial inner ends mounted and fixed into the shaft side rib mounting holes and radial outer ends mounted and fixed into the rim side rib mounting holes, and in the rotor frame, the main magnets and the sub magnets are alternately disposed in the circumferential direction, between the shaft and the rim.

Abstract: An axial gap motor includes: a rotor; and a stator, wherein: the rotor includes a plurality of main permanent magnet parts and a plurality of auxiliary permanent magnet parts, the auxiliary permanent magnet parts being disposed near an end portion of each of the main permanent magnet parts and a magnetizing direction of each of the auxiliary permanent magnet parts corresponding to a direction perpendicular to the direction of the rotational axis; each of the stators includes a plurality of teeth arranged in a circumferential direction and protruding toward the rotor along the rotational axis, and a circumferential distance between a circumferential direction first end and a circumferential direction second end of each of the auxiliary permanent magnet parts on a surface opposite the stator is larger than a slot width of a slot defined between the teeth adjacent in the circumferential direction.

Abstract: The present invention relates to a stepping motor with a magnet pole pattern having a predetermined pattern around the circumference of the stepping motor. In one embodiment, the pattern relates to a code having a unique single maximum autocorrelation peak over the period of the code. Example codes include Barker codes, PN codes, Kasami codes, Golomb ruler codes, and other codes. In one embodiment, the rotor and stator have a matching pole pattern. In one embodiment, the drive is arranged to align the poles in an inline configuration, alternatively, the drive may be arranged to align the poles in a diagonal configuration. In a further embodiment, one or more sets of poles are provided on the stator, each set being offset rotationally by a partial pole spacing.

Abstract: A first member (40a) has a magnet assembly (20) that includes a plurality of permanent magnets (10) held with their homopoles contacting one another. A second member (50a) includes magnet coils (30), and is designed to be changeable in position relative to the first member. The magnet assembly (20) generates the strongest magnetic field in a magnetic field direction lying in the homopolar contact plane at which the homopoles contact one another, the magnetic field direction being oriented outward from the magnet assembly (20) along the magnetic field direction.

Abstract: A rotor of a permanent-magnet-type rotating electrical machine of the present invention has a plurality of magnetic poles in point symmetry with respect to a rotation center of a rotor core 2. For each of the magnetic poles, there are arranged a permanent magnet 3 whose product of a coercive force and a magnetizing direction thickness is small and a permanent magnet 4 whose product of a coercive force and a magnetizing direction thickness is large. The permanent magnet 3 whose product of a coercive force and a magnetizing direction thickness is small is irreversibly magnetized by a magnetic field created by a current of an armature coil 21, to change a total linkage flux amount. This realizes a wide-range variable-speed operation of high output, to provide the rotating electrical machine with a wide operating range and high efficiency.

Abstract: A rotor adapted for a large permanent magnet rotating machine having high output and demagnetization resistance and the permanent magnet rotating machine are provided. More specifically, there is provided a rotor adapted for a permanent magnet rotating machine, the machine comprising the rotor and a stator disposed with a clearance from an outer peripheral face of the rotor and formed by winding a winding wire through a stator core having two or more slots, the rotor comprising one or more permanent magnets in each of two or more insertion holes, the insertion holes being formed in a circumferential direction in a rotor core, wherein a magnetic coercive force in a stator-side surface region of each of the permanent magnets is greater than that in an inner central portion by 300 kA/m or more, the inner central portion being an inner portion at a depth of at least 5 mm from every outer shape face of the permanent magnet.

Abstract: The present invention relates to a permanent magnet generator for increasing the capacity of generating the electric power by increasing the number of a magnetic pole. Thus, the present invention is constructed to largely increase the capacity of generating the electric power by installing the ferromagnetic substances, which are magnetized due to permanent magnets disposed at the rotor, between the permanent magnets thereby easily increasing the number of the magnetic poles twice.

Abstract: Higher-order Halbach permanent magnet arrays that produce higher flux densities in the air gaps of electromotive machines are described. In one embodiment, a second order “Hyper” Halbach array includes a plurality of magnets arranged immediately adjacent to each other so as to define a rectangular matrix having rows and columns in which the respective magnetic fields of a first row of the array are arranged so as to define a conventional first order Halbach array, and, proceeding in a column direction of the array, the respective magnetic fields of the magnets of each of a second and succeeding rows of the array are respectively rotated counter-clockwise about an axis perpendicular to the column direction of the array through successive 90 degree rotations relative to those of the immediately preceding row.

Abstract: A rotor for an electric motor (10) includes a magnetic assembly (12) formed into a ring-shaped plate form, a rotor disc (11) for holding an inner periphery of the magnet assembly, and an outer peripheral ring (13) for holding an outer periphery of the magnet assembly. The magnet assembly is composed of first and second main magnets (12A-1, 12A-2) having magnetizations directions that are oriented perpendicularly and having orientations that are opposite one another, and first and second submagnets (12B-1, 12B-2) having magnetization directions that are oriented perpendicularly in a circumferential direction and having orientations that are opposite one another. At least one group of magnets selected from the main magnets and the submagnets has a wedge-shaped planar part. The planar parts of the first and second main magnets and first and second submagnets form the same plane of rotation. The magnets are arranged so that the magnetization directions of adjacent magnets are perpendicular to one another.

Abstract: A first member (40a) has a magnet assembly (20) that includes a plurality of permanent magnets (10) held with their homopoles contacting one another. A second member (50a) includes magnet coils (30), and is designed to be changeable in position relative to the first member. The magnet assembly (20) generates the strongest magnetic field in a magnetic field direction lying in the homopolar contact plane at which the homopoles contact one another, the magnetic field direction being oriented outward from the magnet assembly (20) along the magnetic field direction.

Abstract: A motor including a bearing structure, a rotor structure, a stator structure and a magnetic body is disclosed. The rotor structure includes a shaft disposed on the bearing structure. The stator structure is disposed corresponding to the rotor structure. The magnetic body is disposed opposite to the shaft and includes a first magnetic element and a second magnetic element. The first magnetic element is disposed around the second magnetic element. A fan including the motor is disclosed as well. The shaft of the fan and the motor thereof are provided with higher axial attraction in operation such that it reduces the abrasion of the shaft and the noise of the motor and the fan.

Abstract: Apparatus and associated methods involve thrust generation by interaction of an armature field with a stator field in an arrangement with substantially reduced flux coupling from the armature to the stator coil. In an illustrative example, solenoid coil segments may be arranged as the stator along a path of motion for the armature. In some examples, each armature may surround and overlap with at least one of the toroidal coil segments. Counter-electromotive force may be substantially reduced, for example, by stopping current flow in a stator coil while overlapped by the armature or while substantial armature flux couples to the stator coil. Thrust may be generated, in some examples, by interaction of armature and stator coil flux in arc-shaped regions external to and between each of the leading and trailing edges of the armature and their respective nearby stator coils.

Abstract: A miniature motor includes a substrate having a pivotal portion. A coil unit and a detection element are provided around the pivotal portion. A rotor is rotatably mounted to the pivotal portion and includes a hub and a permanent magnet mounted to the hub and aligned with the coil unit and the detection element. The permanent magnet includes a plurality of north and south poles each having a stronger magnetism section. A weaker magnetism section is formed between two adjacent stronger magnetism sections. At least one auxiliary starting member is mounted between the substrate and the rotor and aligned with the permanent magnet. When the rotor stops rotating, the at least one auxiliary starting member aligns with and magnetically attracts at least one of the stronger magnetism sections, locating the detection element in a position not aligned with the weaker magnetism sections along an axis of the hub.

Abstract: An armature for a linear motor is described. The armature includes a first of a pair of magnetic structures comprising a first plurality of maglettes each having a magnetic polarity vector; an angle between two adjacent magnetic polarity vectors in the first plurality of maglettes having a first magnitude; and a second of the pair of magnetic structures comprising a second plurality of maglettes each having a magnetic polarity vector; an angle between two adjacent magnetic polarity vectors in the second plurality of maglettes having a second magnitude, the first plurality of maglettes including a first outer maglette that is adjacent to a second outer maglette of the second plurality of maglettes, an angle between the magnetic polarity vectors of the first and second outer maglettes having a third magnitude that is different than at least one of the first and the second magnitudes.

Abstract: A technique of employing a rotor having anti-saliency and being rotatable about a predetermined axis in an axial gap type motor is provided. A plurality of magnets are disposed annularly on a substrate with polarities being symmetric around a shaft hole. For instance, the magnets exhibit N pole and S pole, respectively, on the side of a stator (on this side of sheet of drawing). A plurality of magnetic members are disposed to extend perpendicularly to the direction of a rotation axis, and more specifically, between the magnets.

Abstract: Improvement of torque densities, miniaturization and weight saving for outer rotor type motors or permanent-magnet-field-type DC motors can be efficiently achieved by high-energy densification of a magnet. However, torque pulsation or armature reaction gives negative influences thereto. Further, in application of a slotless (coreless) structure eliminating the torque pulsation or the armature reaction, the magnetic resistance of motor magnetic circuits will be enhanced. For solving the above problems, there is provided an annular magnet that is opened in a reverse direction relative to the opening direction of a U-shaped segment fabricated in constantly-directed magnetic fields, the annular magnet having an anisotropic distribution where angles relative to inner peripheral tangent lines can be continuously changed in the range of approximately 0 to 90 degrees, and having energy density (BH)max of 160 to 186 kJ/m3.

Abstract: A rotor for rotating an electric machine having permanent magnets and flux concentration, including a shaft extending along the rotational axis of the rotor, a rotor body placed on the shaft, the rotor body having a central opening for the mounting thereof on the shaft; radially oriented recesses wherein the permanent magnets are placed; and in at least one angular space separating two consecutive recesses, at least one cavity leading neither to the central opening nor to the two consecutive recesses, the cavity or cavities located in the space occupying an angular area around the rotational axis of the rotor greater than or equal to half of the angular area of the space.

Abstract: To reduce the cogging torque of servomotors, electric power steering motors, and others, there is provided a permanent magnet motor comprising: a rotor 10 comprising a rotor yoke 11 and a plurality of permanent magnets (M1-M10); and a stator 20 comprising a stator yoke 22, salient magnetic poles 21, and armature windings 23, wherein at least one of the permanent magnets is disposed in an adjustment position that is displaced from a corresponding reference position in at least one of the circumferential, radial, and axial directions of the rotor yoke, and the plurality of permanent magnets excluding the permanent magnet disposed in the adjustment position is disposed in the reference positions, and wherein the adjustment position is set so that the permanent magnet motor in which at least one of the plurality of permanent magnets is disposed in the adjustment position has a smaller cogging torque than a permanent magnet motor in which all of the plurality of permanent magnets are disposed in the reference posi

Abstract: A radial anisotropic sintered magnet formed into a cylindrical shape includes a portion oriented in directions tilted at an angle of 30° or more from radial directions, the portion being contained in the magnet at a volume ratio in a range of 2% or more and 50% or less, and a portion oriented in radial directions or in directions tilted at an angle less than 30° from radial directions, the portion being the rest of the total volume of the magnet. The radial anisotropic sintered magnet has excellent magnet characteristics without occurrence of cracks in the steps of sintering and cooling for aging, even if the magnet has a shape of a small ratio between an inner diameter and an outer diameter.

Abstract: A magnet array member with more than four poles is used for being mounted on a shutter of a camera module of a portable mobile communication device, adjacent to one side of a yoke iron of the shutter. The magnet array member includes a disc portion and a driving portion. The disc portion has more than four N poles and S poles, and an annular side face and opposite first end face and second end face. The driving portion protrudes from one of the first end face and the second end face of the disc portion in a vertical direction. Since the driving portion protrudes from one end face of the disc portion, the disc portion can form more than four N poles and S poles when magnetized, thereby being convenient for mass production.

Abstract: A first member (40a) has a magnet assembly (20) that includes a plurality of permanent magnets (10) held with their homopoles contacting one another. A second member (50a) includes magnet coils (30), and is designed to be changeable in position relative to the first member. The magnet assembly (20) generates the strongest magnetic field in a magnetic field direction lying in the homopolar contact plane at which the homopoles contact one another, the magnetic field direction being oriented outward from the magnet assembly (20) along the magnetic field direction.

Abstract: A permanent magnet rotary machine comprises a rotor comprising a rotor core and a plurality of permanent magnet segments embedded in the rotor core and a stator having a plurality of coils and disposed to define a gap with the rotor, or a permanent magnet rotary machine comprises a rotor comprising a rotor core and a plurality of permanent magnet segments mounted on the surface of the rotor core and a stator having a plurality of coils and disposed to define a gap with the rotor. In the rotor, each permanent magnet segment is an assembly of divided permanent magnet pieces, the coercive force near the surface of the magnet piece is higher than that in the interior of the magnet piece, and the assembly allows for electrical conduction between the magnet pieces.

Abstract: In connection with a permanent magnet rotary machine comprising a rotor comprising a rotor core and a plurality of permanent magnet segments embedded in the rotor core and a stator comprising a stator core having a plurality of slots and windings therein, the rotor and the stator being disposed to define a gap therebetween, or a permanent magnet rotary machine comprising a rotor comprising a rotor core and a plurality of permanent magnet segments mounted on the surface of the rotor core and a stator comprising a stator core having a plurality of slots and windings therein, the rotor and the stator being disposed to define a gap therebetween, the rotor wherein each of the permanent magnet segments is an assembly of further divided permanent magnet pieces, and the coercive force near the surface of the magnet piece is higher than that in the interior of the magnet piece.

Abstract: The present invention relates to a rotary electrical machine comprising: at least one stator; and at least one rotor; the rotor having an axis of rotation and co-operating with the stator to define at least one airgap, the rotor comprising permanent magnets and pole pieces between the magnets; at least one pole piece being associated with one or more permanent magnets to concentrate the magnetic flux from said magnet(s); and said magnet(s) defining at least three different directions of magnetization, the resultant flux in the pole piece towards the stator being non-coplanar with at least two of the directions of magnetization.

Abstract: It is desired to design a coreless motor in which a gap size is set to be as small as possible, and a magnet having a large energy product is used in order to increase the gap magnetic flux density since the coreless motor has no iron core so that the magnetic flux density is small in the gap part. A rotor core of the motor has a permanent magnet rotor which is formed by a compression molding means, and which is formed of a compact formed by molding a powder material, the compact comprising a bond magnetic portion mainly composed of a binder and a magnetic powder, and a soft magnetic portion mainly composed of a binder and a soft magnetic powder, the bond magnetic portion having magnetic poles having at least one surface which is mechanically bonded to the soft magnetic portion, in order to solve the inherent problems.

Abstract: This invention provides a rotating electrical machine including a rotor that has an even number of first permanent magnets aligned in a circumferential direction of the rotor, second permanent magnets of a number equal to that of the first permanent magnets, provided respectively between the stator and circumferential ends of the first permanent magnets adjacent to each other in the circumferential direction, and core pieces of a number equal to that of the first permanent magnets, provided respectively between the second permanent magnets adjacent to each other in the circumferential direction.

Abstract: An electro-magnetic motor-generator system, including a wheel assembly having a wheel mounted onto a shaft. The shaft has a sleeve mounted thereon. A frame assembly is mounted onto the sleeve. The frame assembly comprises at least one hub having a sprocket. A gear assembly comprises a second sprocket mounted onto the shaft that engages the sprocket. A rotating ring assembly has first and second walls. The first wall comprises first gear teeth and the second wall comprises second gear teeth. The ring assembly further has consecutive magnetized/non-magnetized sections. The electro-magnetic means consist of at least one coil having first and second openings. Electro-magnetic means generate an electromotive force between said first and second openings, and said consecutive magnetized/non-magnetized sections. Switching said magnetic polarity forces said rotating ring assembly to rotate upon said sprocket thus rotating said wheel mounted onto said shaft.

Abstract: An anisotropic permanent magnet motor includes a stator and a rotor opposed to teeth of the stator with a gap therebetween, and the rotor includes an anisotropic permanent magnet disposed on a surface of a rotor yoke. The anisotropic permanent magnet has an orientation direction set in a direction normal to the outer-peripheral surface in a range of both ?r°/2 from a magnetic pole center and continuously inclined toward a magnetic pole end with respect to a direction normal to the outer-peripheral surface.

Abstract: A permanent magnet has a D-shaped cross section including an arcuate top surface (22), a flat bottom surface (24), and side surfaces (26, 28). Provided that a plurality of permanent magnets are circumferentially arranged so that a great circle (S) circumscribes the apexes (P) on the arcuate top surfaces (22), the top surface (22) includes a central region which delineates an arc of a small circle (T) off-centered from the great circle, and end regions (22a, 22b) which are positioned outside the small circle (T) and inside the great circle (S).

Abstract: A magnetic electron exciter includes a rotor adapted to be rotated within a preselected range of rotational speeds, and having a plurality of magnets mounted therein preselected distances from the rotational axis of the rotor. A plurality of coils are positioned adjacent to the rotor, whereby rotation of the rotor creates an electrical current in the coils. First and second electrodes are spaced apart a predetermined distance, and are electrically connected with the coils to create an arc between the electrodes when the rotor is rotated relative to the coils.

Abstract: A Halbach array is radially disposed in an environment optimized for efficiency and controlled for efficient generation and use of power in order to generate, establish, and maintain a desired level of rotational energy with enhanced efficiency.

Abstract: A permanent magnet machine is provided comprising a stator and a rotor, the rotor being adapted to rotate relative to the stator, the rotor comprising a plurality of permanent magnets separated in the circumferential direction from each other by axially extending rotor pole pieces for concentrating the magnetic flux from the permanent magnets, the stator having a structure that defines axial limits of an air gap between the stator and the rotor for communicating magnetic flux between the stator and the rotor, wherein that at least some of the permanent magnets extend axially outside the axial limits of the air gap as defined by the stator structure.

Abstract: A first member (40a) has a magnet assembly (20) that includes a plurality of permanent magnets (10) held with their homopoles contacting one another. A second member (50a) includes magnet coils (30), and is designed to be changeable in position relative to the first member. The magnet assembly (20) generates the strongest magnetic field in a magnetic field direction lying in the homopolar contact plane at which the homopoles contact one another, the magnetic field direction being oriented outward from the magnet assembly (20) along the magnetic field direction.

Abstract: A sintered magnet and a rotating machine equipped therewith are disclosed, which include: crystal grains of a ferromagnetic material consisting mainly of iron, and a fluoride compound or an oxyfluoride compound, containing at least one element selected from the group consisting of an alkali metal element, an alkaline earth metal element, and a rare earth element, the fluoride compound or the oxyfluoride compound being formed inside some of the crystal grains or in a part of a grain boundary part. The oxyfluoride compound or the fluoride compound contains carbon, and a grain boundary width of the ferromagnetic material is smaller than a grain boundary width of the ferromagnetic material in which the fluoride compound or the oxyfluoride compound is formed.

Abstract: The present invention relates to a stepping motor with a magnet pole pattern having a predetermined pattern around the circumference of the stepping motor. In one embodiment, the pattern relates to a code having a unique single maximum autocorrelation peak over the period of the code. Example codes include Barker codes, PN codes, Kasami codes, Golomb ruler codes, and other codes. In one embodiment, the rotor and stator have a matching pole pattern. In one embodiment, the drive is arranged to align the poles in an inline configuration, alternatively, the drive may be arranged to align the poles in a diagonal configuration. In a further embodiment, one or more sets of poles are provided on the stator, each set being offset rotationally by a partial pole spacing.

Abstract: A magnet element (37) and a method of its manufacture for assembly into a rotor (38), the magnet element (37) having magnetic domains aligned anisotropically to form a domain alignment pattern (42), wherein the magnetic domain alignment pattern (42) in the magnet element (37) has an orientation that varies substantially continuously across at least part of the magnet element (37) between its lateral edges from at least partially radial to at least partially tangential.

Abstract: The invention relates to an electrical machine of the transversal-flux type. The machine comprises a stator and a movable element. The stator has a plurality of stator elements with magnetic flux conductors and an electric winding extending in a closed winding path through each magnetic flux conductor. The movable element comprises a number of permanent-magnet members and is movable in relation to the stator along a movement path. The winding path comprises a first current-carrying section extending along the movement path. Each magnetic flux conductor forms, together with one of the permanent-magnet members, a closed magnetic flux circuit around said current-carrying section. Each permanent-magnet member comprises a primary magnet with a magnetic direction across the movement path.

Abstract: A permanent magnet machine includes a stator having a hollow core, a rotor rotatably disposed inside the hollow core, and a plurality of multilayered permanent magnets embedded in the rotor. Each multilayered permanent magnet has opposite first and second ends, and includes a first magnet disposed at the first end, and a second magnet disposed at the second end and coupled to the first magnet. The second magnet has higher magnet strength than the first magnet, and also has lower high-temperature stability than the first magnet.

Abstract: This invention provides a soft magnetic yoke-integrated bonded magnet in which a soft magnetic yoke has been integrally compression molded in such a state that the soft magnetic yoke is engaged in a joined face formed by bringing a binding material-containing magnetic powder into contact with a binding material-containing soft magnetic powder. The soft magnetic yoke part and the bonded magnetic part are constructed so that, when the soft magnetic yoke part and the bonded magnet part are compression molded separately from each other, the spring back level is identical upon the release of the compression force.

Abstract: An internal permanent magnet machine (“IPM machine”) of the type used, for example, with traction motors and hybrid electric vehicles, includes a rotor having a plurality of ferrite magnets arranged in one or more layers, wherein at least one of the layers includes rare earth magnets (e.g., NdFeB magnets) adjacent to the ferrite magnets to prevent or reduce demagnetization.

Abstract: Magnetic poles of a ring magnet are fanned by magnetizing multiple small regions that are set in each of magnetic pole regions that are set in an outer peripheral face of the ring magnet so as to correspond to the magnetic poles. The small regions are set in such a manner that the proportion of a region that is magnetized increases from a boundary portion of each magnetic pole region toward a center portion of the magnetic pole region in the circumferential direction.

Abstract: An object of the present invention is to provide a rotor magnet that is capable of adjusting attraction of magnet that is mounted in a spindle motor, a spindle motor including the same, a recording and reproducing apparatus, and a jig for manufacturing the same, with a simple configuration. A rotor magnet is an approximately annular member that is attached to a rotor hub rotating around a shaft forming a part of a spindle motor. The rotor magnet is magnetized such that magnetization properties of axially top and bottom surfaces of the rotor magnet are different from each other.

Abstract: To improve resistance of a motor device against an organic solvent and to suppress degradation in performance of the motor device with time. In a motor device, an excitation magnet is formed using a hollow-cylinder shaped anisotropic bonded magnet 13. This bonded magnet 13 is press-fitted in a housing 12 and is held. The bonded magnet 13 is formed of a hollow-cylinder shaped anisotropic rare earth bonded magnet which is obtained by compounding an anisotropic rare earth magnet powder with a phenol-novolac type epoxy resin, followed by molding. The anisotropic rare earth bonded magnet 13 is press-fitted along an inner peripheral portion of the housing 12, and on an exposed surface layer of the anisotropic rare earth bonded magnet press-fitted in the housing, a coating layer is formed by an infiltration treatment using a polyamide-imide-based resin.

Abstract: A disk drive device includes: a hub on which a recording disk is to be mounted; a base configured to rotatably support the hub via a bearing; a core that is fixed to the base and includes a circular portion and S salient poles (where S is a natural number greater than or equal to 3) extending from the circular portion in the diameter direction; a three-phase coil that is formed by being wound around each of the S salient poles; and a magnet that is fixed to the hub and faces the S salient poles in the diameter direction, and that is provided with P driving magnetic poles in the circumferential direction (where P is a natural number greater than or equal to 2).

Abstract: The sintered magnet and the rotating machine equipped with the same are disclosed. The sintered magnet includes crystal grains of a ferromagnetic material consisting mainly of iron, and a fluoride compound or oxyfluoride compound layer containing at least one element selected from an alkali metal element, an alkali earth metal element, and a rare earth element. The layer is formed inside some of the crystal grains or in a part of a grain boundary part. An oxyfluoride compound or fluoride compound layer containing carbon in a stratified form is formed on an outermost surface of the crystal grains. The fluoride compound or oxyfluoride compound layer has a concentration gradient of carbon, contains at least one light rare earth element and at least one heavy rare earth element. The heavy rare earth element has a concentration lower than that of the light rare earth element.

Abstract: A permanent magnet rotor of a brushless direct current (BLDC) motor, in which cogging torque ripple and electromagnetic vibration noise transferred to the permanent magnet rotor can be blocked and a motor's power-to-weight ratio can be improved. A conventional BLDC motor has to use an electric steel sheet core so as to maintain the maximum magnetic flux density of the permanent magnet rotor and to minimize a rotating electric field loss. As a result, cogging torque vibration is unavoidably transferred to a load side through the motor rotary shaft. However, the rotor can enable stable driving of the BLDC motor by innovatively blocking the cogging torque vibration and the electromagnetic vibration noise and can greatly reduce the motor's weight by using a plastic or non-magnetic material instead of an electric steel sheet core.