619 results about "Magnet device" patented technology

Medical devices and methods for magnetically positioning a device within a body cavity of a patient, including a removable magnet unit that can be reused across procedures.

This invention provides a small polar electromagnet device of small power consumption. Provided is a polar electromagnet device in which a drive shaft (61) is supported so as to reciprocate in an axis center direction at a center hole (31c) of a spool (31) wound with a coil (32), a movable iron core (42) is attached to a lower end of the drive shaft (61) on the same axis center, and the drive shaft (61) is reciprocated with the movable iron core (42) which reciprocates based on excitation and demagnetization of the coil. A permanent magnet (45) is integrally arranged at the movable iron core (42) on the same axis center.

An eigen-mode to be corrected is selected in accordance with an attainable magnetic field accuracy (homogeneity) and appropriateness of arranged volume of the iron pieces. Because the adjustment can be made with the attainable magnetic field accuracy (homogeneity) being grasped, an erroneous adjustment can be grasped, and the adjustment is automatically done during repeated adjustment. When the magnetic field adjustment is carried out with support by the method of the present invention according to the first and second embodiments or an apparatus including this method therein, the magnetic field adjustment can be surely completed. As a result, the apparatus with a high accuracy can be provided. In addition, there is an advantageous effect of earlier detection of a poor magnet by checking the attainable homogeneity. They are applicable to magnet devices for the horizontal magnetic field type, being an open type MRI, and vertical magnetic field type MRI.

The invention relates to a magnetorheological finishing device applicable to ultra-large-diameter optical processing. The magnetorheological finishing device comprises a magnet device and a magnetorheological fluid circulating device. The magnet device is capable of providing a magnetic field, the lower end of the magnet device is provided with a horizontal protruding section, and the magnetorheological fluid circulating device enables magnetorheological fluid flowing through the horizontal protruding section to form a ribbon protrusion under the action of the magnetic field perpendicular to the flowing direction. The magnetorheological finishing device applicable to ultra-large-diameter optical processing can be modified on a finishing machine tool to replace a finishing head, such as a stress plate, a small grinding head and the like of the finishing machine tool without changing an original mechanical structure of the machine tool. The magnetorheological finishing device has the advantages that system size is reduced, mechanical structure is simplified, material removal efficiency is improved, and accordingly the current problems of long processing period and low removal efficiency of large-diameter aspherical processing are solved.

A superconductive magnet device comprises a pair of oppositely disposed superconductive bodies in which annular superconductive coils are accommodated, and fine chip-shaped ferromagnetic shims disposed on a surface of the pair of superconductive magnet bodies so as to improve uniformity of magnetic field in a uniform magnetic field in a uniform magnetic field space generated in the proximity of the center between the superconductive magnet bodies, wherein ring-shaped ferromagnetic shims are disposed concentrically with the center of annular superconductive coils on the surface of the superconductive magnet bodies.

A pivot bearing device, particularly for a rotating circular table of a machine tool is provided, and includes a first device part, which is to be connected to an element that is to be rotatably mounted, particularly to the circular table, and a second fixed device part. The device parts are connected via at least one antifriction bearing upon which an axial force acts. A magnet device ( 21 ), which acts between the first and second device parts ( 2, 3 ), is provided for generating a compensating force (F_k) oriented in essentially the opposite direction to the axial force (F_a).

The invention discloses a single degree of freedom magnetic suspension rotor support system as well as a magnetic bearing and weight losing method. The support system is composed of complete permanent magnetic radial magnetic suspension bearings, or driving/driven mixed type magnetic suspension bearings, or complete permanent magnetic pre-stress magnetic suspension bearings, as well as a weight losing bias magnet device and a radial/axial air gap limit protection device, wherein, the complete permanent magnetic radial magnetic suspension bearings, or driving/driven mixed type magnetic suspension bearings, or complete permanent magnetic pre-stress magnetic suspension bearings are arranged at the left and right of an electric motor (5) and maintain good proper alignment with the stator/rotor parts of the electric motor. By utilizing the synergic action of the axial stabilizing force of electric motor and the radial stabilizing force of magnetic bearings, the rotating part in the system is constrained in a single degree of freedom magnetic suspension state of only doing tangential dead axle rotation. The complete permanent magnetic radial magnetic suspension bearings (6, 7) are formed by respectively arranging two annular permanent magnets and maintaining the heights of interfaces at two sides to be symmetrical and the interfaces at two sides to attract each other via axial air gap, wherein the two annular permanent magnets are magnetized axially, have equivalent magnetic pole face, different volumes and magnetic attraction forces, and are respectively provided with an external magnetism conductive yoke.

The invention discloses a polishing device for a construction steel bar, comprising a bottom plate, a roller device, a magnet device, a support device, a polishing structure, a blowing device and a regulating device; the roller device comprises a first supporting rod, a first cushion block, a first cross rod, a first locating rod, an air cylinder, a first spring, a pushing rod, a supporting block and a first roller; the magnet device comprises a first magnet, a bent rod, a second magnet, a third magnet, a clamping rod and a second spring; the support device comprises a second supporting rod, a first inclined rod, a second cross rod, a third cross rod, a first vertical rod, a fourth cross rod, a fifth cross rod, a second vertical rod and a second inclined rod; the polishing structure comprises a moving rod, a polishing wheel, a baffle, a third vertical rod, a locating rack, a first support, a sixth cross rod, a third spring, a locating block and a fourth spring; and the blowing device comprises a fixed frame, a first connecting rod, a draught fan, a blow pipe and a blow hopper. The polishing device can be used for rapidly polishing the steel bar and is high in polishing efficiency.

A magnet arrangement includes (a) a first and a second head ring magnet each having a substantially circular geometry with respect to a centre axis and (b) a central ring magnet having a substantially circular geometry with respect to a centre axis. The central ring magnet is disposed between the first and second head ring magnet in direction of the centre axis. At least one of the magnets includes a first number of first magnets having at least one trapezoidal cross section and a second number of second magnets having at least one rectangular cross section. The second magnets are disposed in between the first magnets in circumferential direction. With this geometrical arrangement, magnets having a trapezoidal cross section include a guidance for a magnet having a rectangular cross section allowing the movements in radial direction of these last magnets.

A method and system for monitoring the performance of a permanent magnet device, such as a motor or generator, and providing early detection of motor performance deterioration. The back electromotive force (EMF) of the motor is measured at selected conditions when the motor is in a normal healthy condition to obtain a reference signature response. A measured signature is then obtained periodically during the life of the motor at the same conditions as the reference signature to check the current back EMF characteristic of the motor. If the measured signature deviates from the reference signature by a predetermined threshold, it indicates that the motor performance has degraded to a condition requiring attention.

The invention discloses a hybrid film coating method of a neodymium iron boron rare earth permanent magnet device. According to the method, firstly, alloy smelting is carried out, alloy in a molten state is cast onto a rotary copper roller with a water cooling effect for being cooled to be manufactured into an alloy sheet, then, the alloy sheet is subjected to hydrogen decrepitation, material mixing and airflow powder grinding, next, materials are mixed by a material mixing machine and are then sent to a nitrogen gas protection magnetic field orientation pressing machine to be formed, the mixed materials are subjected to isostatic pressing after being encapsulated in a protection box, then, the sintering and the aging are carried out, a neodymium iron boron rare earth permanent magnet blank is prepared, the blank is subjected to machining, a neodymium iron boron rare earth permanent magnet is prepared, next, the neodymium iron boron rare earth permanent magnet is subjected to film coating, the neodymium iron boron rare earth permanent magnet device is formed, the film coating comprises three layers, the first layer and the second layer are magnetron sputtering coatings, and the second layer is a magnetron sputtering and multi-arc ion plating hybrid coating. The hybrid film coating is adopted as a surface treatment work procedure of the rare earth permanent magnet device, the anti-corrosion capability of the rare earth permanent magnet device is improved, and meanwhile, the magnetic performance of the rare earth permanent magnet device is also improved.

The invention obtains a superconductive magnet device for preventing damage to a coil container caused by the occurrence of a quench phenomenon, vacuum break or the like, when blocking by freezing is generated in a pipeline for connecting the coil container to the outside of a vacuum container. The superconductive magnet device comprises the coil container for accommodating a superconductive coil and a liquefied refrigerant for cooling the superconductive coil to a critical point or smaller, the vacuum container for performing the vacuum heat insulation of the coil container from the outside by including the coil container, and the pipeline whose one end communicates with the inside of the coil container and the other end is located outside the vacuum container. A heating means for heating the pipeline is provided at least at one location of a part piped to the inside of the vacuum container in the pipeline. Even if a constituent for causing freezing in air or the like in the pipeline enters for freezing, the heating means heats the pipeline for melting freezing and for canceling the blocking of the pipeline.

A magnet device includes two sets of static magnetic field generation sources spaced from each other in the vertical direction such that the uniform magnetic field region (patient space) is between then. Each set has concentric current carrying coils to generate a uniform magnetic field in a first direction (the vertical direction). Several such coils are used in each set, disposed such that when a first axis which is parallel to the first (vertical) direction and passes substantially through the centers of the current carrying coils crosses, at a first point, a second axis which is orthogonal to the first axis and is at substantially equal distance from the respective static magnetic field generation sources, the current carrying coils are disposed in such a manner that when geometrical centers of cross sections of the current carrying coils are projected on a first straight line that is in a first plane containing the first axis, the second axis and the first point and passing through the first point, the directions of the currents of the carrying coils at the respective corresponding projections align alternatively in positive and negative directions on the first straight line.

A magnet apparatus comprising a plurality of geometrically shaped nested magnetic elements each being of a different size relative to each other and each having a first side with a first magnetic pole orientation and a second side with a second magnetic pole orientation that is opposite to the first magnetic pole orientation, capable of being assembled concentrically to form a single planar magnet array having a treatment surface and an opposing backer surface, the treatment surface having either an all like magnetic pole orientation or a mixed magnetic pole orientation; and a backer plate having a first side and a second side constructed of ferromagnetic material such that when the plurality of geometrically shaped nested magnetic elements is assembled concentrically on the first side of the backer plate each of the geometrically shaped nested magnetic elements that comprise the single planar magnet array is secured to the first side of the backer plate by magnetic attraction whereby the treatment surface of the single planar magnet array is formed opposite to the backer surface of the single planar magnet array that is magnetically secured to the backer plate.

The invention provides a novel plane magnetron sputtering cathode. The plane magnetron sputtering cathode comprises a target material, a backboard, a magnet device and a magnetic conductive plate. The target material is arranged at one side of the backboard, and the magnetic conductive plate is arranged at the other side of the backboard. The magnet device is arranged between the backboard and the magnetic conductive plate. The magnet device comprises a middle magnet and an outer ring magnet surrounding the middle magnet. The middle magnet comprises at least two electromagnets. The polarities of magnetic poles, facing the target material, of the outer ring magnet and the middle magnet are opposite. The plane magnetron sputtering cathode further comprises an electromagnet power source. The electromagnet power source is connected with the at least two electromagnets and supplies power to the at least two electromagnets in sequence so that magnetic field distribution between the outer ring magnet and the middle magnet can be changed continuously. By implementing the novel plane magnetron sputtering cathode, the target material utilization rate can be effectively increased, pollution to the target material is prevented, and stability of the sputtering speed is improved. In addition, the plane magnetron sputtering cathode provided by the invention has the characteristics of being simple in structure, easy to control and high in reliability.

A side-looking NMR logging tool incorporates a permanent magnet arrangement having a magnetization direction oriented towards a side of the tool and a dipole RE antenna displaced towards the front of the tool. The magnet arrangement produces a shaped region of investigation in front of the tool wherein the magnetic field has a uniform field strength and the RF field has a uniform field strength in a direction orthogonal to the static field. The shaping of the static field is accomplished by the magnet arrangement comprising a plurality of magnets having parallel magnetization or by a single shaped magnet. The antenna arrangement includes a gapped core made of non-ferritic soft material for increasing the antenna efficiency. The magnet arrangement also reduces ringing in the core and the antenna. An optional RF shield is used to reduce NMR signals from borehole fluids.

The invention discloses an improved Halbach array permanent magnet device, which belongs to the field of permanent magnet mechanisms. Although the uniformity of the magnetic field of a Halbach array permanent magnet is improved, obvious repulsion between magnetic poles of same magnetic property exists during the installation of fan-shaped magnetic blocks, so the installation is complicated and difficult. The permanent magnet device is a hollow cylindrical permanent magnet, which is equally divided into N=2<M> blocks along the circumferential direction, wherein M is an integer more than 2; the axial cross section of each equally divided block of the permanent magnet device has a shape of isosceles triangle; the side of one of two adjacent isosceles triangles is overlapped with the base of the other isosceles triangle; an included angle between the side and the base of the triangle is 2pi/N; and the axial cross section of the permanent magnet device has a hollow regular N-sided shape, and the side of the hollow regular N-sided shape is that of the isosceles triangles. By improving the Halbach array permanent magnet, the device has the advantages of simple structure, high utilization ratio of the permanent magnet material, low machining cost, convenient installation, high utilization ratio of the magnetic field space, high uniformity of the magnetic field, less magnetic leakage and capability of easily increasing the field strength, greatly reducing the size of the magnet and reducing the manufacturing cost of the instrument.

A self-regulating permanent magnet device has a first rotor segment and second rotor segment, each supporting a set of permanent magnets, wherein the position of the second rotor segment relative to the first rotor segment is modified based on the speed of the self-regulating permanent magnet device. By modifying the position of the second rotor segment relative to the first rotor segment, the alignment between their respective sets of permanent magnets, and therefore, the electromotive force (emf) generated in the stator coils is regulated. The position of the second rotor segment is defined by the connection of a torsion spring between the first rotor segment and second rotor segment and a reactionary torque device connected to the second rotor segment. The torsion spring creates a spring force that acts to maintain the alignment between the first rotor segment and the second rotor segment. The reactionary torque device provides reactionary torque that is proportional to the speed of the self-regulating permanent magnet device and opposes the spring force. As the speed of the self-regulating permanent magnet device increases, the reactionary torque causes the second rotor segment to rotate, thereby creating a misalignment between the first rotor segment and second rotor segment.

The invention discloses a preparation method of a SmCu alloy doped samarium-cobalt-based nano composite permanent magnet, belonging to the technical field of magnetic materials. The material takes 1:5-type SmCo nanometer magnet and nanocrystalline alpha-Fe composite magnet as the base body, employs the magnetron sputtering and spark plasma sintering technology to take the low melting point Sm_6Cu_4 alloy as interface phase to improve the grain boundary and diffuse into the hard magnetic phase, , thus improving the magnet coercivity, and the Sm-Co based nanocrystalline composite permanent magnet with good magnetic properties was obtained. At that same time, the invention has the advantage of simple process and low cost, and is favorable for the application of samarium-cobalt-based nano composite permanent magnet in more permanent magnet device.