201results about How to "Uniform magnetic field distribution" patented technology

The invention relates to a small CPT atomic clock physical system, and belongs to the technical field of atomic frequency standard. The physical system comprises a laser portion and an atom air chamber portion. The laser portion comprises a VCSEL laser tube, an aperture diaphragm, and a [lambda]/4 wave plate. The atom air chamber portion comprises an atom air chamber, a C field coil, a thermistor, a low electromagnetic film electric heating sheet, and a photoelectric detector. The C field coil uses a reverse Helmholtz coil structure to realize. Heating methods of the low electromagnetic film electric heating sheet and high-frequency AC electric heating are used to heat the atom air chamber. The system uses a vacuum heat insulation technology to package. The output frequency of the physical system is high in stability, stable in performance, small in volume, low in power consumption, and low in cost, and is especially suitable to be used for a glass type atom air chamber whose sealing port is on the central position of a cylindrical surface.

The invention discloses an omnidirectional A0 modal Lamb wave electromagnetic acoustic sensor, and belongs to the field of ultrasonic non-destructive testing. A double-layer spiral inflection coil structure is integrated in a flexible circuit board, and the omnidirectional A0 modal Lamb wave electromagnetic acoustic sensor is designed and developed to excite single A0 modal Lamb waves in an aluminum plate. The developed electromagnetic acoustic sensor is verified by experiments, the single A0 modal Lamb waves can be excited in the aluminum plate, defects in the aluminum plate are detected by the sensor, and positioning precision is high. The developed electromagnetic acoustic sensor has fine frequency response characteristics according to verification by scanning frequency experiments, and the developed electromagnetic acoustic sensor has fine omnidirectional characteristics according to verification by omnidirectional characteristic testing experiments. By the aid of the developed omnidirectional A0 modal Lamb wave electromagnetic acoustic sensor and an array combination imaging algorithm thereof, wide-range and high-efficiency defect imaging of a plate structure can be realized, and the sensor has great application values and potentials in the field of health monitoring and non-destructive evaluation for the plate structure.

The continual casting directional solidification method for TiAl-base alloy plate comprises, putting TiAl alloy material bar 3 and dummy ingot 4 with rectangular intersection into the electromagnetic induction range of coil 6, galvanizing to coil 6 with single-phase alternating current with power of 75~100kW from electrical power for 20~25min; the alloy bar 3 and ingot 4 move downward with velocity of 0.01-0.05mm/min and get into the bottom crystallizer 8. This invention overcomes the limit to rectangular intersection blank and fits to press for high performance material in economy, science and national defense industry.

The invention provides a Cr-Cr nanometer composite metal ceramic coating as well as a preparation method and device thereof. The coating is provided with a Cr diffusion layer, a Cr bonding layer, a Cr transition layer, a CrNx supporting layer, a Cr/CrN corrosion-resistant layer and a Cr decoration layer, wherein the CrNx supporting layer satisfies 0<=x<1; the Cr/CrN corrosion-resistant layer is an alternating layer of Cr layers and CrN layers and provided with at least one layer of Cr layer and one CrN layer. The coating provided by the invention has gradual changes of structure and composition, good interlayer bonding and excellent corrosion resistance and comprehensive properties.

The invention discloses a transmitting coil structure with high-quality factor and a winding method thereof. A transmitting coil comprises a coil, an insulation layer attached to the coil and a shielding layer attached to the insulation layer. The coil is composed of M turns of loosely-intertwined winding wires and N turns of closely-intertwined winding wires. The spacing distance between turns of M turns of loosely-intertwined winding wires is larger than that between turns of N turns of closely-intertwined winding wires. M is less than N.The coil winding method thereof can help greatly the proximity effect of the coil, reduce loss and decrease the dead zone range of a magnetic field of the transmitting coil such that the quality factor of the transmitting coil is greatly increased. In addition, uniform magnetic field distribution is generated around the transmitting coil so that energy is effectively transmitted.

The present invention provides a double-layer sector array folded coil structure integrated in a flexible circuit board, and designs and develops an arrayed omnidirectional type horizontal shear modal magnetostrictive transducer. Based on the magnetostrictive effect of ferromagnetic material nickel, the transducer realizes excitation of omnidirectional horizontal shear modal SH wave in the plate structure. Test verifies that the developed arrayed omnidirectional type horizontal shear modal magnetostrictive transducer can excite single SH0 modal waveguide inaluminum plate, and verifies that the developed omnidirectional type horizontal shear modal magnetostrictive transducer has better frequency response characteristics. The developed omnidirectional type horizontal shear modal magnetostrictive transducer and an array combined imaging algorithm can achieve efficient defect imaging on plate structure in wide range and board structure, and has very great value and potential in health monitoring and non-destructive evaluation of the plate structure.

The invention provides an intermediate-voltage concatenated frequency converter, a pre-charging method and an intermediate-voltage concatenated frequency converter system. The intermediate-voltage concatenated frequency converter comprises a phase shift transformer, a power unit group and a pre-charging module, wherein the pre-charging module is used for converting power voltage input by the input end of the pre-charging module into pre-charging voltage which is consistent with the output voltage of a secondary winding of the phase shift transformer; the pre-charging voltage is connected with and output to any secondary winding of the phase shift transformer or the input end of any power unit of the power unit group through the output end of the pre-charging module to pre-charge the intermediate-voltage concatenated frequency converter; the pre-charging module comprises a contactor, a resistor and a transformer, and is connected to the low-voltage side of the intermediate-voltage concatenated frequency converter; and all the devices of the pre-charging module adopt low-voltage devices. By the technical scheme, the downsizing of a circuit is facilitated.

The invention discloses a method for compound magnetic powder flaw detection, comprising the following steps: (1) pretreating; (2) magnetizing; (3) applying magnetic powder or magnetic suspension; (4) observing and recording a magnetic trace; (5) rating the flaw; (6) demagnetizing; and (7) post-treating. The magnetizing mode in the step (2) is circumferential closed magnet yoke magnetization and coil magnetization full sensing. The magnetic powder flaw detection method designed by the technical scheme of the invention has the advantage of high work efficiency, lightens the labor intensity of workers, avoids fire striking phenomenon, does not burn workpieces and has even magnetic field distribution.

The rectangle cold crucible system fit to casting continually and directional solidification comprises mould cavity 1-1 of crucible body 1 with proportion of width, length and height as 1:2~6:10~20 that belongs to fillet transition of two near surfaces and four square platform of big end down; opening splits with number about 6~18 run through outer surface 1-2 to mould cavity 1-1 on crucible body 1. This invention has no pollution to material, prepares heterotype alloy blank of high quality, overcomes the limit to rectangular intersection blank and fits to requirement of metallurgical and aerospace industry.

The invention discloses an electric machine having in each case at least two clamping protrusions for attaching a permanent magnet. The present invention relates to a spoke rotor for an electric machine, having a main body which extends concentrically around an axis of rotation and which has a plurality of pole shoes, between which permanent magnets are arranged in holders, wherein there is provided for each permanent magnet in its holder in each case at least one first clamping element and one second clamping element, which fixes said permanent magnet in the holder, wherein the first clamping element fixes the permanent magnet in a radial direction relative to the axis of rotation and the second clamping element fixes it in a tangential direction relative to the axis of rotation, and wherein in each case a movement clearance is provided for each second clamping element. The present invention also relates to a clamping lamella, in particular for such a spoke rotor. The present invention also relates to an electric machine comprising such a spoke rotor. The present invention also relates to a device, in particular a hand-held power tool, an adjustment drive for a motor vehicle, a power steering system, a servo motor, an electromechanical brake booster or a vehicle drive, comprising such an electric machine.

The invention relates to a fixing structure of a permanent magnet generator or a motor permanent magnet. The fixing structure comprises a rotor cylinder and permanent magnets, wherein the permanent magnets are arranged along the circumference of the surface of the rotor cylinder at intervals. Pole shoes are arranged among the permanent magnets along the circumference of the surface of the rotor cylinder and are used for fixing the permanent magnets, and a protruding part for clamping tightly the permanent magnets on two sides is respectively arranged on two side surfaces of each pole shoe. Each permanent magnet is fixed on the surface of the rotor cylinder by virtue of adjacent pole shoes on the two sides of each permanent magnet. According to the invention, the problem that the fixation of a current generator permanent magnet is not firm and consumes time and labors is effectively solved, the air gaps between the rotor and the stator can be reduced and the working efficiency of the generator is improved.

The invention discloses an omnidirectional magnetic concentrator type lamb wave electromagnetic acoustic transducer, wherein the transducer comprises a cylindrical neodymium-iron-boron magnet, a magnetic concentrator and a circular array type back-folding line ring. The multi-cluster circular zigzag line ring in a flexible circuit board is placed on the surface of an aluminum plate to be detected,and the magnetic concentrator and the neodymium-iron-boron magnet are attracted and then placed right above a return line ring. Based on lorentz force effect, the stimulating of omni-directional S0 modal guided wave in a plate structure is realized. Experiments verify that the prepared array type omnidirectional magnetic concentrator type lamb wave electromagnetic acoustic transducer can be usedfor stimulating a single S0 mode guided wave in the aluminum plate; with an omni-directional test experiment carried out, the developed omnidirectional magnetic concentrator type lamb wave electromagnetic acoustic transducer can stimulate to a S0 guide wave spread in the 360-degree direction; and a defect detection experiment verifies that the omnidirectional magnetic concentrator type lamb wave electromagnetic acoustic transducer can effectively reduce the analysis difficulties and errors of defect signals.

The invention discloses a single loudspeaker and a production method of the single loudspeaker. The single loudspeaker comprises a magnetic cover, a magnet and a washer which are arranged in sequence. The centers of the magnetic cover, the magnet and the washer are provided with holes. The holes are consistent in shape and size. A fixed column is arranged in the single loudspeaker. The shape of the fixed column is matched with the shapes of the holes. The magnetic cover, the magnet and the washer sleeve the fixed column and are concentrically fixed together by the fixed column. Through arrangement of the holes at the centers of the magnetic cover, the magnet and the washer of the single loudspeaker, the magnetic cover, the magnet and the washer are brought together in a penetrating manner by the fixed column which is matched with the holes in shape. The magnetic cover, the magnet and the washer are firmly fixed together on the premise of ensuring the concentricity of the magnetic cover, the magnet and the washer. According to the single loudspeaker with such a structural design, distribution of the magnetic field generated by a magnetic circuit system is uniform, a high-quality sound effect is provided, the magnetic circuit system is fixed through adoption of the fixed column, therefore, the strength is relatively high, the reliability is high, and the service life of the product can be improved.

A magnetic Fe3O4 nano-particle/flake aluminium pigment composite nanometer material is disclosed. The composite nanometer material is prepared by in-situ synthesis of Fe3O4 nano-particles on surfaces of flake aluminium particles by a high-temperature oil phase method. A preparation process is green, safe, and free of pollution to the environment. According to the composite nanometer material, when the composite nanometer material is added into a pigment matrix, the Fe3O4 nano-particles are uniformly distributed in the pigment matrix and are not liable to agglomerate, and distribution of a magnetic field is more uniform.

The invention discloses a low-energy-consumption method for separating ilmenites from tailings in an iron choosing plant. The method comprises the following steps: firstly, by taking the tailings in the iron choosing plant as raw materials, separating the tailings by using a permanent magnet drum-type mediate-intensity magnetic separator; discharging non-magnetic materials directly taken as magnetic separation tailings; next, grinding mediate magnetic separation concentrates taken as magnetic materials under the conditions that the monomer separation of the ilmenites is effectively realized while the grinding concentrates, the fineness of which is controlled as -75mu m, account for 75% to 95%; performing low-intensity magnetic separation on the mediate magnetic separation concentrates by using a low-intensity magnetic separator so as to separate iron concentrates and lead the rest of mineral materials to enter the next step; performing rough separation on the rest of mineral materials and then performing fine separation on the concentrates for multiple times after the rough separation so as to obtain ilmenite concentrates; performing sweeping separation on the tailings after the rough separation; combining the useful mineral materials for multiple times after the sweeping separation; returning the tailings after the fine separation into a rough separation process; and finally discharging the tailings which are subjected to the sweeping separation are taken as the ilmenites. The method is simple in process, reasonable in magnetic path design, uniform in magnetic field distribution, high in metal recovery rate and good in separation quality.

The invention discloses a 5-point generatrix configuration method of a large-area inequipotential electricity type. It is composed of the cathode soft generatrix, cathode generatrix, bottom generatrix, side generatrix, lower column generatrix and electrobath. The lower column generatrix is 5-piece configuration. The invention not only can make the current passing every column appropriate and effectively reduce the magnetic field in the slot and the transverse magnetic field, but also match with every slot paramete of the large-scale slot. Especially compared with the two columns, the center columune has low current and is benefit to reduce the danger caused by the middle level magnetic field in the electrobath to make the electrobath more stable.

The invention provides a magnetron assembly and magnetron sputtering equipment. The magnetron assembly comprises a center permanent magnet and annular permanent magnets surrounding the center permanent magnet. The polarity of the center permanent magnet is opposite to that of the annular permanent magnets. The annular permanent magnets are of an integrated structure. According to the magnetron assembly provided by the invention, installing is convenient and safe, the distribution uniformity of outer ring magnetic fields can further be improved, the higher magnetic field intensity is achieved under the condition of the same-size outer ring magnets, and thus the higher power density can be obtained under the condition that the effect that the magnetic field intensity is not decreased is ensured.