Abstract: A Nd—Fe—B type anisotropic exchange spring magnet is produced by a method of obtaining powder of a Nd—Fe—B type rare earth magnet alloy which comprises hard magnetic phases and soft magnetic phases wherein a minimum width of the soft magnetic phases is smaller than or equal to 1 &mgr;m and a minimum distance between the soft magnetic phases is greater than or equal to 0.1 &mgr;m, obtaining a compressed powder body by compressing the powder, and obtaining the Nd—Fe—B type anisotropic exchange spring magnet by sintering the compressed powder body using a discharge plasma sintering unit.

Abstract: A bulk exchange-spring magnet 12, a method of producing the same, and a device 20 incorporating the bulk exchange-spring magnet are disclosed. The magnet includes magnet powders 10 having hard and soft phases, and boron and oxygen atoms which cohere in boundary areas 16 between grains 14 of the densified magnet powders 10. In a production method, the magnet powders 10 are compacted so as to incorporate boron and oxygen atoms into the boundary areas 16 and are heated under a compacted state of the magnet powders at varying operating temperatures for a given time period. This results in formation of a highly densified magnet at a lower potential operating temperature for a shorter time period without the grain growth. The device 20 includes the bulk exchange-spring magnet 12 containing the boron and oxygen atoms cohering between the grains of the densified magnet powders.

Abstract: A rotor structure for a permanent-magnet motor is disclosed as including an annular laminated stack (2) of electromagnetic steel sheets incorporating magnets, annular end plates (1a, 1b) located at both ends of the annular laminated stack to hold the same, a cylindrical core buck (3) carrying thereon the annular laminated stack and the annular end plates, and a rotor shaft (5) integrally connected to the cylindrical core buck for rotating movement. The annular laminated stack has a plurality of first fixing portions (8a, 8a′, 8a″; 8b, 8b′, 8b″), and each of the annular end plates has a plurality of second fixing portions (7a, 7a′, 7a″; 7b, 7b′, 7b″) which are held in engagement with the first fixing portions of the annular laminated stack, with the annular end plates and the annular laminated stack being fixed to one another by caulking at the first and second fixing portions.

Abstract: A rare earth magnet comprises rare earth magnet particles and a rare earth oxide being present between the rare earth magnet particles.

Abstract: An electrical-steel-sheet formed body is provided with an opening portion into which a permanent magnet is inserted, and an outer-peripheral hardened portion formed on the electrical-steel-sheet formed body at an outer periphery side thereof for the opening portion and having a higher hardness than a remaining area of the electrical-steel-sheet formed body. The electrical-steel-sheet formed body can be used as the rotor of the built-in permanent magnet type rotary electric machine, and the built-in permanent magnet type rotary electric machine can be obtained.

Abstract: This invention relates to an anisotropic magnet having excellent magnetic characteristics such as a high magnetic flux density, a process for producing the same, and a motor having the same.

Abstract: An exchange-spring magnet is prepared using a magnet alloy containing Ta and C in addition to Nd, Fe and B. This exchange-spring magnet uses the magnet alloy prepared by a liquid quenching method or a mechanical alloying method. Further, by subjecting the magnetic alloy having a part set in an amorphous state to heat treatment, an exchange-spring magnet exhibits good properties regarding magnetic flux density and coercive force.

Abstract: A Nd—Fe—B type rare earth magnet alloy is provided with hard magnetic phases each of which has a size equal to or less than 80 nm, soft magnetic phases each of which has a size equal to or less than 80 nm, with the hard and soft magnetic phases being present in a mixed structure, and partly anisotropic regions wherein axes of easy magnetization of the hard magnetic phases are aligned in one direction and each having a size equal to or greater than 0.1 &mgr;m. Such a magnet alloy is obtained using a strip casting method or ultra cooling method and serves as material for an anisotropic exchange spring magnet to be applied to a motor.

Abstract: A rotor (11) for a synchronous motor is provided with a plurality of magnets (15) being substantially V-shaped in cross-section. The V-shaped cross-section is defined by an inner V-surface (25), an outer V-surface (19) and an outward face (23) facing outwardly. A first angle &agr; is subtended between a first straight line connecting a point of intersection (31) of the outer V-surface (19) and the outward face (23) and a second straight line connecting the center (35) of the rotor (11) and the acute angle point (27). A second angle &bgr; is subtended between the first straight line and a third straight line connecting a point of intersection (33) of the inner V-surface (25) and the outward face (23). By setting the angle &bgr; to be larger than 20 percent of the angle &agr;, leakage flux at both ends of the magnets (15) is reduced.

Abstract: This invention relates to an anisotropic magnet having excellent magnetic characteristics such as a high magnetic flux density, a process for producing the same, and a motor having the same.

Abstract: A rotor structure for a permanent-magnet motor is disclosed as including an annular laminated stack (2) of electromagnetic steel sheets incorporating magnets, annular end plates (1a, 1b) located at both ends of the annular laminated stack to hold the same, a cylindrical core buck (3) carrying thereon the annular laminated stack and the annular end plates, and a rotor shaft (5) integrally connected to the cylindrical core buck for rotating movement. The annular laminated stack has a plurality of first fixing portions (8a, 8a′, 8a″; 8b, 8b′, 8b″), and each of the annular end plates has a plurality of second fixing portions (7a, 7a′, 7a″; 7b, 7b′, 7b″) which are held in engagement with the first fixing portions of the annular laminated stack, with the annular end plates and the annular laminated stack being fixed to one another by caulking at the first and second fixing portions.

Abstract: A bulk exchange-spring magnet 12, a method of producing the same, and a device 20 incorporating the bulk exchange-spring magnet are disclosed. The magnet includes magnet powders 10 having hard and soft phases, and boron and oxygen atoms which cohere in boundary areas 16 between grains 14 of the densified magnet powders 10. In a production method, the magnet powders 10 are compacted so as to incorporate boron and oxygen atoms into the boundary areas 16 and are heated under a compacted state of the magnet powders at varying operating temperatures for a given time period. This results in formation of a highly densified magnet at a lower potential operating temperature for a shorter time period without the grain growth. The device 20 includes the bulk exchange-spring magnet 12 containing the boron and oxygen atoms cohering between the grains of the densified magnet powders.

Abstract: An anisotropic exchange spring magnet powder complexing a hard magnetic material and a soft magnetic material, wherein a rare earth metal element, a transition metal element, boron and carbon and the like are contained, and the hard magnetic material and soft magnetic material have crystal particle diameters of 150 nm or less. A method of producing an anisotropic exchange spring magnet powder comprises treating a crystalline mother material containing a hard magnetic material and soft magnetic material or the crystalline mother material having amorphous parts, in a continuous process composed of an amorphousating process and the following crystallizing process, repeated once or more times. An anisotropic exchange spring magnet is obtained by treatment, in an anisotropy-imparting molding process and a solidification process, of an anisotropic exchange spring magnet powder.

Abstract: A rotor (11) for a synchronous motor is provided with a plurality of magnets (15) being substantially V-shaped in cross-section. The V-shaped cross-section is defined by an inner V-surface (25), an outer V-surface (19) and an outward face (23) facing outwardly. A first angle &agr; is subtended between a first straight line connecting a point of intersection (31) of the outer V-surface (19) and the outward face (23) and a second straight line connecting the center (35) of the rotor (11) and the acute angle point (27). A second angle &bgr; is subtended between the first straight line and a third straight line connecting a point of intersection (33) of the inner V-surface (25) and the outward face (23). By setting the angle &bgr;, to be larger than 20 percent of the angle &agr;, leakage flux at both ends of the magnets (15) is reduced.

Abstract: To obtain stable linear torque-output characteristics over a wide torque range in a magnetostrictive torque detecting apparatus having a shaft to be measured, an exciting coil for magnetically exciting the shaft, and a detecting coil for detecting magnetostrictive components generated in the shaft distorted by a torque, the shaft is particularly composed of a substrate shaft portion made of a high yield point material and a shape anisotropic layer portion made of a high magnetostrictive material metallographically welded on an outer surface of the substrate shaft. The welded shape anisotropic layer portion is formed with two symmetrical groups of concave/convex portions each arranged at regular angular intervals on the outer circumferential surface thereof at an inclination angle with respect to the axial direction of the shaft.

Abstract: A magnetostriction type torque sensor employs a plurality of detector coils arranged in axial arrangement along an objective rotary body. The detector coils are so designed and arranged as to compensate influence of temperature, particularly the error caused due to axial temperature gradient caused in the objective rotary body.