700results about "Permanent magnet manufacture" patented technology

Methods, devices and systems for forming magnetic anastomoses between two blood vessels. A first anastomotic component is removably supported by the distal end of a delivery device for attachment to a first vessel. The delivery device also supports a second anastomotic component that has been secured to a second blood vessel. The device is operated to secure the first component to the first vessel, couple the second component to the first component, and then release the components to complete the anastomosis. A robotic anastomosis system includes several robotic instruments that may be positioned through ports in a patient, used to secure an anastomotic component to a vessel, and then used to magnetically couple the components. Delivery devices for deploying magnetic anastomotic components include an actuator that uses magnetic repulsion to move the components into engagement with the inner and outer surfaces of the vessel wall. The anastomotic components are secured to the vessel wall by magnetic force and in addition may be secured by mechanical attachment.

A permanent magnet in which the magnetization direction varies with location to optimize or restrict a magnetic field property in a selected direction at a selected point. The magnetic field property may be, for example, the transverse magnetic field, axial magnetic field, axial gradient of the transverse magnetic field, transverse gradient of the transverse magnetic field, axis gradient of the axial magnetic field, transverse gradient of the axial magnetic field, the product of the transverse magnetic field and the transverse gradient of the transverse magnetic field, the product of the transverse magnetic field and the axial gradient of the transverse magnetic field, the product of the axial magnetic field and the transverse gradient of the axial magnetic field, or the product of the axial magnetic field and the axial gradient of the axial magnetic field. The magnet may be formed of one or more segments in which the magnetization direction varies smoothly and continuously, or the magnet may be formed of a plurality of segments in which the magnetization direction is constant. A method of making and using such magnets is also disclosed.

The present invention provides miniaturization of brushless motors and brush motors used in electric devices, a ring magnet which simultaneously achieves both high torque and a reduction in cogging torque, a ring magnet with yoke, and a brushless motor. The thin hybrid magnetized ring magnet of the present invention is structured of, in a ring magnet comprised of a plurality of magnetic poles, a radially magnetized main pole and an interface for which the interface of the adjoining main pole is polar anisotropic. When the thin hybrid magnetized ring magnet structured in this manner is applied to a brushless motor, in the case of radial magnetizing, the abrupt change in magnetic flux of the interface between the magnetic poles becomes smooth and cogging torque is greatly reduced due to polar anisotropic magnetization of the interface. At the same time, by polar anisotropically magnetizing the interface between the magnetic poles, magnetic flux is concentrated on the radially magnetized main pole, and in comparison to only radial magnetization, maximum surface magnetic flux improves and it is possible to attain high torque.

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. Good motor characteristics can be attained by setting an angle to 5-40° between the direction of magnetization of the permanent magnet and a diametral direction passing the bonding surface.

Its basic means is a monolithically bonded construct prepared by monolithically bonding together a rare-earth magnet 2 and a an alloy material that is a high melting point metal or a high specific-tenacity material through the solid phase diffusion bonding by the hot isostatic pressing treatment, and a monolithically bonded construct with an interposal of a thin layer of the high melting point metal between a rare-earth magnet 2 and an alloy material 3, 4 that is a high specific-tenacity material. As a method for the bonding, there is used a hot isostatic pressing treatment method in which a rare-earth An magnet and a high melting-point metal are laminated together, thereby to prepare an object to be treated, then the object is put into a hermetic-type high pressure container having an inner wall portion equipped with a heater, then the object is uniformly pressurized in all directions by a synergistic effect caused by pressure and temperature, while the object is maintained for a certain period of time under a certain pressure and temperature condition in an atmosphere of an inert gas, thereby to monolithically bond the object. With this, it is possible to obtain a bonded construct in which a magnet can monolithically be bonded with another metal member with a high strength, without deteriorating magnetic characteristics, such that the rare-earth magnet's insufficiency in brittleness, rigidity, tenacity and the like is compensated.

The object of the present invention is to provide a rare-earth magnet having a sufficient corrosion resistance, and a method of manufacturing the same. The rare-earth element in accordance with a preferred embodiment comprises a magnet body containing a rare-earth element, and a protective layer formed on a surface of the magnet body. The protective layer in accordance with a preferred embodiment includes a first layer covering the magnet body and containing a rare-earth element, and a second layer covering the first layer and containing substantially no rare-earth element. Another protective layer in accordance with a preferred embodiment comprises an inner protective layer and an outer protective layer successively from the magnet body side. The outer protective layer is any of an oxide layer, a resin layer, a metal salt layer, and a layer containing an organic-inorganic hybrid compound.

The present invention relates to a cylindrical permanent magnet which is used in a micro DC brushless motor used in a compact hard disc etc. An Sm—Co based magnetic material is used as a magnetic material and the permanent magnet has domains magnetized in a radial direction and arranged at regular intervals in a circumferential direction. Provided that P represents a pitch corresponding to an average of an inner circumferential length and outer circumferential length in one of the domains, D denotes an inner diameter of the permanent magnet, t represents a thickness in the radial direction, N represents the number of domains, and M represents the number of AC phases for driving the motor, D is set to 20 (mm) or smaller and t is set to satisfy the relation of t≦πD/(NM−π).

The invention discloses a method for forming a circular ring-shaped magnet of which the radiation orientation is along the radius direction or the diameter direction; the key points of the invention are that the oriented magnetic field is changed from the 360-degree distribution(or approximately 360-degree distribution) which is generally adopted at present to a very small part of 360 degrees of the radiation ring; the relative state between the magnetic powders in the forming process and the oriented magnetic field is changed from the relative rest(or approximately relative rest) which is generally adopted at present to the relative motion. The former mainly aims at getting larger oriented magnetic field and the latter aims at magnetizing and orienting the magnetic powders in a molding cavity at the 360-degree direction. The forming method of the invention can preferably resolve the technical problems generally existing in the making of the present radiation ring that the magnetic powders are not completely oriented due to the relatively low oriented magnetic field and the consistency of the magnetic performance of the radiation ring is not good due to the uneven distribution of the oriented magnetic field.

A rotating machine comprising a sintered ferrite magnet having an M-type ferrite structure, comprising Ca, an R element that is at least one of rare earth elements and indispensably includes La, Ba, Fe and Co as indispensable elements, and having a composition represented by the formula: Ca_1-x-yR_xBa_yFe_2n-zCo_z, wherein (1−x−y), x, y, z and n represent the contents of Ca, the R element, Ba and Co, and a molar ratio, meeting 0.3≦1−x−y≦0.65, 0.2≦x≦0.65, 0.001≦y≦0.2, 0.03≦z≦0.65, 4≦n≦7, and 1−x−y>y; a bonded magnet comprising ferrite powder having the above composition and a binder, and a magnet roll, at least one magnetic pole portion of which is made of the above bonded magnet.

Hydrogen embrittlement is prevented in Sm₂Co₁₇-based magnets and R₂Fe₁₄B-based magnets by metal plating the magnet, then carrying out heat treatment, or by forming a metal oxide or metal nitride layer on the metal plating layer or directly on the magnet itself.

A magnetic device is provided for holding paper memos, documents, notices, notes, photos and similar non-magnetic thin sheet materials against a flat or rounded, usually vertically oriented, magnetically attractive surface such as a refrigerator door. It comprises two neodymium disc magnets attached to a steel plate. The entire assembly is encapsulated in silicone rubber. The steel plate serves as a rigid structural splint. The steel plate also serves to focus the magnetic fields of the two magnets, thereby increasing the device's magnetic strength without increasing the size of the magnets.

[Object] To improve resistance of a motor device against an organic solvent and to suppress degradation in performance of the motor device with time.

[Solving Means] 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.

Anisotropic rare earth-iron based resin bonded magnet comprises: [1] a continuous phase including: (1) a spherical Sm₂Fe₁₇N₃ based magnetic material covered with epoxy oligomer where its average particle size is 1 to 10 μm, its average aspect ratio AR_ave is 0.8 or more, and mechanical milling is not applied after Sm—Fe alloy is nitrided; (2) a linear polymer with active hydrogen group reacting to the oligomer; and (3) additive; and [2] a discontinuous phase being an Nd₂Fe₁₄B based magnetic material coated with the epoxy oligomer where its average particle size is 50 to 150 μm, and its average aspect ratio AR_ave is 0.65 or more, further satisfying: [3] the air-gap ratio of a granular compound on the phases is 5% or less; and [4] a composition where crosslinking agent with 10 μm or less is adhered on the granular compound is formed at 50 MPa or less.