175results about How to "Improve resistance to demagnetization" patented technology

The invention discloses a method for preparing a high-coercivity sintered Nd-Fe-B permanent magnet. The method includes the following steps that firstly, the vacuum rapid hardening technology is used for preparing Nd-Fe-B alloy magnetic material blank; secondly, chamfering, cleaning, washing, surface modifying and washing are sequentially performed on the blank; thirdly, a processed permanent magnet is placed to a nickel/heavy rare earth composite coating for being electroplated; fourthly, a sintered Nd-Fe-B magnetic material is placed into a vacuum heat treatment furnace to receive heat treatment. With the technology of compositing heavy rare earth on a nickel-plate, heavy rare earth solid matter can be effectively utilized, and maximum benefits of rare earth resources are achieved. Meanwhile, it is ensured that the proportion of the content of the heavy rare earth in the nickel-plate is stable, volatile matter which is prone to decomposition does not exist in the nickel-plate in subsequent heat treatment to pollute a vacuum heat treatment system, a production device with infiltration of the heavy rare earth can be stable continuously, the application range of a technology is wider, and the method can be popularized and applied in an enterprise more easily.

A rotor of a motor includes a plurality of sets of permanent magnets 8a, 8b embedded in the rotor. Each includes a permanent magnet at an inner side and another permanent magnet at an outer side with a distance between them. Each permanent magnet 8a, 8b is formed like an arch projecting towards the center of the rotor. Magnetic flux flows easily through an interval between the permanent magnets at inner and outer sides, and the inductance in a q-axis is enlarged. Then, the reluctance torque is generated in addition to the magnet torque, and the motor has a high torque and a high output power.

The invention discloses a rotor of a permanent magnet synchronous motor and the permanent magnet synchronous motor, which belong to the technical field of the permanent magnet synchronous motors, and are designed in order to solve the problems of high leakage flux, low permanent magnet utilization rate, influence on motor performance and efficiency and the like in existing rotor of the permanent magnet synchronous motor. The rotor of the permanent magnet synchronous motor comprises a rotor core, wherein an even number n of tangential permanent magnets are distributed evenly in radial direction on the rotor core, and the same polarities of two adjacent tangential permanent magnets are opposite; radial permanent magnets are arranged symmetrically on two sides of one end of each tangential permanent magnet close to the inner side of the rotor core respectively; every two radial permanent magnets sandwiched between two adjacent tangential permanent magnets have the same polarity in the direction facing to a stator, and a magnetic isolating bridge is arranged between every two radial permanent magnets. The invention further discloses a permanent magnet synchronous motor provided with the rotor. By utilizing the rotor, the leakage flux of the tangential permanent magnets on the inner side of the rotor is reduced, the utilization rate of the permanent magnets is improved, and the motor efficiency and the motor structural intensity are enhanced.

To provide a motor including: an annular stator including permanent magnets and stator cores that are alternately arranged circumferentially, and coils; an annular outer-rotor being arranged outside the stator, having a rotational axis coincident with a central axis of the stator, and having first salient poles; and an annular inner-rotor being arranged inside the stator, having a rotational axis coincident with the central axis to rotate in conjunction with the outer-rotor, and having second salient poles equal in number to the first salient poles, the magnets are magnetized circumferentially and extend radially, and each have respective ends that are opened toward the outer-rotor and toward inner-rotor in the radial direction, the coils are each wound by concentrated-winding on a tooth constituted from a different one magnet and respective parts of two stator cores adjacent to the magnet, and the first and second salient poles are arranged at offset positions circumferentially.

The invention provides a spliced block type tangential magnetizing brushless motor rotor structure with built-in magnetic steel. The spliced block type tangential magnetizing brushless motor rotor structure with the built-in magnetic steel comprises rotor sheet assemblies, a supporting frame 2, the magnetic steel 3, rivets 4, partition plates 5 and a rotating shaft 6. The rotor sheet assemblies are mutually independent, and the magnetic steel 3 conducts tangential magnetizing inside the brushless motor rotor structure. The rotor sheet assemblies are mainly formed by interspersing and stacking a plurality of rotor sheets 1 through the rivets 4, the rotor sheets 1 are arranged on the supporting frame 2 in a spliced mode under the effect of the rivets 4, and flanges are arranged on the rotor sheets 1. The partition plates 5 are arranged on the two sides of the magnetic steel 3 respectively, and the rotating shaft 6 is arranged in a center hole of the supporting frame 2. The invention further provides a corresponding assembly method and a corresponding motor. Rotor leakage can be effectively reduced, the performance of the motor is improved, and the parts are firmly matched, so that the magnetic steel cannot be thrown away; the magnetic steel is not over against air gaps, demagnetization resistance is effectively improved, a traditional narrow side magnetism separation bridge is omitted, and manufacturability of the motor is obviously improved.

The invention discloses a rotor of a permanent magnet motor. The rotor comprises a rotor core with a plurality of installation grooves and permanent magnets installed in the installation grooves. The rotor core is provided with a central hole and a plurality of sections of cylindrical surfaces, a magnetic bridge is connected between adjacent cylindrical surfaces, the outside surface of each magnetic bridge is much closer to the central hole of the rotor core relative to the cylindrical surfaces, the outside surface of each magnetic bridge is outwards concave from the installation grooves to form a groove in the magnetic bridge, and the widths of the grooves are smaller than that of those of the installation grooves. Compared with the prior art, the rotor of the permanent magnet motor has the advantages that the magnetic bridges and the grooves are arranged to allow a motor with the rotor to obtain low cogging torque, reversed electromotive force tending to the sine and low load torque pulsation. The rotor has the advantages of being simple in manufacturing process, high in mechanical strength, low in noise and high in demagnetization-resistance performance due to appropriate multi-section arc or the line-section magnetic bridges, and the rotor is applicable to motors of roller washing machines.

The invention relates to a novel sintered ndfeb permanent magnet and a preparation method thereof. The composition expression of the sintered ndfeb permanent magnet is (Cex, Nd1-x)y-Mz-Fe100-y-zB0.9-1.05, wherein x is greater than or equal to 0.05 and smaller than or equal to 0.1, y is greater than or equal to 0.4 and smaller than or equal to 0.9, z is greater than or equal to 0.5 and smaller than or equal to 5, and M is one or several of Gd, Co, Al, Cu and Zr. After the composition of the sintered ndfeb permanent magnet is designed and the production technology is improved, the material cost of the product is reduced, the integrated performance is improved, the cost performance is increased comprehensively, and the magnetic property and the anti-demagnetization performance are improved; moreover, the manufacturing cost of the product is reduced effectively, and based on the current unit price of raw materials, the cost can be reduced by 16.5 yuan/kilo, and the power consumption can be reduced by 1 kwh/kilo.

The invention discloses a semi-magnet-isolated double-excitation linear synchronous motor. It includes primary iron core, primary winding, secondary iron core, secondary excitation winding, secondary excitation winding slot, permanent magnet, generator and cogging, and secondary excitation winding is wound on the core teeth and placed on the secondary excitation In the winding slot, the characteristic is that there are two permanent magnets for excitation under each magnetic pole, placed obliquely, corresponding to each other, fixed in the embedded groove in the middle of the secondary yoke, and facing upward at an angle of 120°. There is a trapezoidal magnetic isolation air between the adjacent ends of each pair of permanent magnets; the faces of the same polarity of the two permanent magnets under the same magnetic pole are facing the same direction, and the N and S magnetic poles are alternately distributed along the length direction of the secondary yoke; the permanent magnets The upper end is close to the secondary excitation winding slot and connected by the magnetic bridge of the secondary iron core. The integrity of the secondary iron core is good, and the levitation force and thrust of the motor are significantly increased under the same conditions. It is mainly used in various occasions of maglev transportation system drive and logistics line drive.

Construction of a permanent magnet rotor assembly having a plurality of magnetic poles and comprising a number of magnetic pole pieces arranged in circular array. Two sets of permanent magnets—one set magnetised in circumferential direction of the rotor and the second set providing flux in axial direction of rotor, generating a magnetic flux focused through the pole piece and interacting with the magnetic flux of the stator. End-plates made of magnetic material are present such there is an axial gap between the them and the array of magnetic pole pieces. Circumferentially magnetised magnets are placed in the circumferential gaps between the pole pieces, whereas the magnets providing flux in axial direction are placed in the gaps between the array of pole pieces and end-plates.

The invention discloses a self-starting permanent magnet synchronous motor rotor adopting a conductive sleeve. The self-starting permanent magnet synchronous motor rotor comprises an iron core, a permanent magnet, a shaft and the conductive sleeve, wherein the conductive sleeve is wrapped at the outer side of the iron core of the rotor to form a rotor starting winding; and the conductive sleeve is made of a non-magnetic good conductor material. Compared with the prior art, the self-starting permanent magnet synchronous motor rotor has the beneficial effects: 1, the equivalent air gap length of a motor is increased by means of the conductive sleeve, and the influence of magnetomotive force of stator current demagnetization on the permanent magnet is weakened; 2, the resistance of the conductive sleeve is lower and the equivalent winding of the rotor is enhanced; 3, the air gap length of the motor is increased by means of the conductive sleeve, and internal eddy-current loss and stray loss of the motor are favorably reduced; 4, the mechanical strength of the rotor can be enhanced by means of the conductive sleeve, a magnetic isolation bridge inside the rotor can be made to be narrower, and high enough utilization rate of the permanent magnet is ensured; and 5, the torque pulsation caused by slotting on the surface of the rotor during steady-state running is reduced, and vibration and noise of the motor are restricted.

The invention discloses a split type combined permanent magnet brushless motor for an electric vehicle. A rotor is coaxially positioned in the internal of a stator; a rectangular neodymium iron boron permanent magnet steel and two same rectangular ferrite permanent magnet steels are fixedly embedded in each pole of the rotor; the neodymium iron boron permanent magnet steels are close to air gaps and are symmetrical relative to the central line of the rotor poles; the two ferrite permanent magnet steels are close to a rotation shaft, are distributed on the two sides of the central line of the rotor poles and are symmetrical relative to the central line of the rotor poles; a magnetic conductive bridge is between the two ferrite permanent magnet steels; the permanent magnet steel on each pole is magnetized along the tangential direction of the circumference; the magnetizing directions on the same pole are the same, and the magnetizing directions on the adjacent two poles are opposite; the rare earth permanent magnet material and the non-rare-earth ferrite permanent magnet material are adopted at the same time; on the basis of ensuring the power density and the torque density of the permanent magnet motor with a small amount of rare earth, the cost of the motor is reduced by more than 50%; and in addition, the requirements on the torque and the power in the electric vehicle applications can be met on the premise of keeping the relatively high power density and the torque density.