36results about How to "Eliminate magnetic flux leakage" patented technology

A thin film magnetic recording head is provided with a tape bearing surface that has magnetically isolated channels while still providing a maximum continuous surface area with which to engage the media. This can be accomplished by providing spaces in the magnetically permeable thin film that are large enough to prevent cross-talk between the channels, but small enough to prevent significant interference with the moving media. Alternatively, magnetically impermeable thin film spacers can be provided to magnetically isolate each of the channels. The spacers are generally even with the magnetically permeable thin film so as to provide a continuous media-bearing surface.

The invention relates to a permanent magnet motor. The permanent magnet motor comprises a stator and a rotator arranged in the stator, wherein the rotator comprises a plurality of permanent magnets which are arranged at intervals along the circumferential direction of the rotator, the permanent magnets are made of ferrite materials and are polarized along the circumferential direction of the rotator, the cross section of each permanent magnet is trapezoid, the edge, close to the center of the rotator, of each permanent magnet is the short edge of the trapezoid, and the edge, far away from the center of the rotator, of each permanent magnet is the long edge of the trapezoid. The motor is an 8-pole 9-groove motor, and is in a multi-pole built-in-type magnetic concentrating structure, so that the gap flux density of the motor is larger than the flux density of the surfaces of the permanent magnets, the gap flux density of the motor is largely improved, and therefore the motor with high power density and high torque density is obtained through the ferrite materials. A fragmentation rotator structure is adopted, so that magnetic flux leakage of a magnetic bridge is eliminated, the torque density of the motor is further improved, and the torque density of the ferrite motor reaches or approaches to the torque density of a surface mounted rare earth permanent magnet motor. The invention further provides an electric tool and a mower utilizing the permanent magnet motor.

The invention relates to a permanent magnetic motor. The permanent magnetic motor comprises a stator and a rotor arranged inside the stator. The stator comprises a stator core provided with 12 stator teeth and a coil wound on the stator teeth, and the rotor comprises a rotating shaft and at least one magnetic core set which is fixed on the rotating shaft. The magnetic core set comprises 8 rotor cores and 8 permanent magnets, wherein the 8 rotor cores are arranged at intervals in the circumferential direction of the rotor, each permanent magnet is made of ferrite materials, each permanent magnet is clamped between two adjacent rotor cores, each permanent magnet is polarized in the circumferential direction of the rotor, and the polarities of every two adjacent permanent magnets are opposite. According to the permanent magnetic motor, a multi-polarity embedded magnetic focusing structure is applied, so that the gap flux density of the motor is improved, the objective that a high power density and a high torque density are obtained through the ferrite materials is realized, and the objective that the torque density of the ferrite motor is equal to or approximates that of a surface-attached rare-earth permanent magnet motor is realized. In addition, the permanent magnetic motor is low in noise and meets design requirements. The invention further provides a bladeless fan with the permanent magnetic motor.

The invention discloses a giant magnetostriction rotary ultrasonic vibration device comprising a knife handle, a primary winding, and two sets of bearing systems. A secondary winding is arranged on the knife handle, and the primary winding and the secondary winding are connected through inductive coupling; a giant magnetostriction transducer is installed at the lower part of the knife handle; thegiant magnetostriction transducer is sleeved with the two sets of bearing systems; and the bottoms of two sets of bearing systems are opposite and the two sets of bearing systems are connected by screw threads. An air cooling system is adopted to cool the giant magnetostriction transducer, and the problem of heat generation of the giant magnetostriction transducer in actual processing can be effectively solved; copper stranded wires are adopted by driving coils, compared with commonly used copper wires, the copper stranded wires are more conducive to heat dissipation, and the operating temperature of the coils is reduced; a thin-walled sleeve inside a transducer shell and a flange are arranged to ensure the coaxiality of the flange and the transducer shell, and the giant magnetostriction rod is subjected to uniform pre-tightening force; and the sleeve is arranged to facilitate the outward diffusion of heat generated by the giant magnetostriction rod and the coils.

The present invention provides a kind of Halbach permanent magnet array structure that reduces flux leakage, comprising Halbach permanent magnet array body, carbon fiber protective sleeve and Fe-based soft magnetic composite material; Halbach permanent magnet array body is composed of multiple radially magnetized permanent magnets and multiple Tangentially charged permanent magnets are alternately arranged and combined; the outer surface of the Halbach permanent magnet array body is composed of a magnetic collecting surface and multiple magnetic shielding surfaces; the magnetic collecting surface is covered with a carbon fiber protective sleeve; the magnetic shielding surface is covered with There is a carbon fiber protective cover, and the Fe-based soft magnetic composite material is fixed on the carbon fiber protective cover. The invention adopts the carbon fiber protective sheath and the Fe-based soft magnetic composite material to cover, which greatly reduces the magnetic flux leakage, and can even completely eliminate the magnetic flux leakage. The arrangement of the Fe-based soft magnetic composite material can enhance the magnetic induction intensity at the air gap region. The Halbach permanent magnet array structure of the present invention can be applied in radial permanent magnet bearings and disc type iron-coreless bilateral permanent magnet motors.

The invention discloses a three-dimensional three-phase amorphous alloy transformer iron core, which comprises a three-phase core, three single-phase iron core covers and six inner iron yoke covers. The three-phase iron core is formed by assembling three closed rectangular frame type single-phase cores according to an equilateral triangle shape, the three single-phase cores are respectively formed through winding amorphous alloy tapes with different widths, and the cross-sections of a left iron core column, a right iron core column, an upper iron yoke and a lower iron yoke are isosceles trapezoid-shaped with the length of the upper bottoms identical to length of the waist parts and the length of the lower bottoms being twice as along as the upper bottoms; the three iron core columns of the three-phase iron core are formed through gluing the iron core columns of two single-phase cores with the lower bottoms of the cross-sections being adhered, so that the cross-sections of the three iron core columns of the three-phase iron core forming an equilateral hexagon; the three single-phase iron core covers are correspondingly sleeved outside the three single-phase cores, so that the threeiron core columns of the three-phase iron core are packaged in iron core column shells; and the six inner iron yoke covers are correspondingly connected with yoke covers so that three upper yokes andthree lower yokes of the three-phase iron core are packaged in yoke shells.