163results about How to "Increase magnetic density" patented technology

A magnetic recording medium which has a non-magnetic substrate and a magnetic layer formed on the non-magnetic substrate, in which the magnetic layer contains magnetic powder with a particle size of 40 nm or less and a binder, an autocovariance length Ma of the magnetic layer in its lengthwise direction is 70 nm or less, an autocovariance length Mb of the magnetic layer in its widthwise direction is 80 nm or less, and a ratio Ma/Mb is from 0.80 to 1.20.

The magnetic tape device includes a magnetic tape and a TMR head, in which the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, an intensity ratio of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, and a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00.

The present invention provides a carbon film forming method capable of forming a dense carbon film with high hardness. The carbon film forming method includes: introducing a raw material gas G including carbon into a deposition chamber 101 whose internal pressure is reduced; ionizing the raw material gas G using a discharge between a filament-shaped cathode electrode 104 heated by electrical power and an anode electrode 105 provided around the cathode electrode; and accelerating and radiating the ionized gas to the surface of a substrate D. A magnetic field is applied by a permanent magnet 109 to increase the ion density of the ionized gas accelerated and radiated to the surface of the substrate D. In this way, it is possible to form a carbon film with high hardness and high density on the surface of the substrate D.

A magnetoresistive head and a fabricating method thereof accomplishing high read sensitivity and excellent linear response with low noise even if track width narrowing makes progress are provided. In one embodiment, using a magnetoresistive film having a laminated body of a pinned layer/an intermediate layer/a free layer/a separate layer/a first ferromagnetic layer/a 90-degree magnetic interlayer coupling layer/a second ferromagnetic layer, and the magnetizations of both the pinned layer and the second ferromagnetic layer are fixed nearly in the direction along the sensor height. On the other hand, the magnetizations of the first ferromagnetic layer and the second ferromagnetic layer have an interlayer interaction being directed in nearly orthogonal directions to each other through the 90-degree magnetic interlayer coupling layer, and the first ferromagnetic layer has a magnetization directed nearly in the direction along the track width in zero external magnetic field. According to this, the first ferromagnetic layer applies a longitudinal biasing field to the free layer nearly in the direction along the track width.

The invention discloses a double-stator three-freedom-degree decoupling lorentz-force magnetic bearing. The lorentz-force magnetic bearing mainly comprises two parts, namely, a rotor system and a stator system, wherein the rotor system mainly comprises a magnetic-conductive ring, an axial magnetic-isolated ring, an axial magnetic steel, an axial locking nut, a deflection magnetic-isolated ring, deflection magnetic steel and a deflection locking nut; the stator system mainly comprises a deflection stator skeleton, a deflection winding, an axial stator skeleton, an axial winding and epoxy resin glue. The double-stator three-freedom-degree decoupling lorentz-force magnetic bearing disclosed by the invention has the advantages that axial translation and radial two-freedom-degree deflection control can be realized and the translation control and the radial deflection control are completely decoupled, so that the control performance and the control accuracy of the magnetic bearing are improved; simultaneously, since the magnetic flux and the magnetic density in air gaps are constant, outputted force and torque and the control current have the relative good linearity, so that the control accuracy of the magnetic bearing is further improved.

A magnetic recording medium has a seed layer provided on a substrate surface, an underlayer provided on the underlayer, and a recording layer provided on the underlayer. Information is recorded in the recording layer by magnetizing the recording layer in a recording direction. The seed layer is formed by a polycrystal of crystal grains made of an alloy material having a B2 crystal structure, and a [100] crystal orientation of the crystal grains are inclined towards one of two sides partitioned by a plane that is formed by the recording direction and a substrate normal which is normal to the substrate surface.

The invention belongs to the technical field of motors and discloses a motor stator iron core, a motor stator, a motor and a manufacturing method of the motor stator. The motor stator comprises the motor stator iron core. The motor comprises the motor stator and the motor stator iron core. According to the motor stator iron core, one end or two ends of an iron core body are provided with tooth boot boss portions, the purpose of increasing the axial length of the motor stator iron core can be achieved, and the turn length of a winding is not increased; besides, the flux of a magnet on a rotor can be guided to stator teeth through the tooth boot boss portions, the magnetism gathering effect is better, the flux density of the stator iron core can be improved, the material utilization rate is higher, and the weight of the motor stator iron core is reduced. Meanwhile, the turn length of the winding of the motor stator is reduced, the weight of the winding is reduced, the length of the end of the motor is reduced, and the motor is high in performance and low in cost.

The invention provides a tangential steel magnet permanent magnetism synchro motor, which belongs to the permanent-magnet motors. The motor comprises a stator consisting of a stator core (1) and an armature winding (2), and a rotor consisting of a tangential magnetization permanent magnet (3), a North Pole magnetizer of the rotor (4), an S-pole magnetizer (5) of the rotor, a fixed cover (7) arranged on a driving end, a fixed cover (8) arranged on a non-driving end (8), an axis of rotation (6) and a bearing (9). The rotor and the stator are arranged in a front end cover (10), a back end cover (11) and an enclosure (12). The axial length of the tangential magnetization permanent magnet (3), the North Pole magnetizer of the rotor (4) and the S-pole magnetizer (5) of the rotor (5) is larger than the axial length of the stator core (1); the end connection length can be used effectively. Due to the axial magnetic concentration action of the rotor core, the air-gap induction of the motor is increased; and the power density of the permanent-magnet motor is further increased. The utility model is highly valuable in application in aerospace and civil occasions requiring high performance.

An e-type iron-based oxide magnetic particle powder has narrow particle size distribution and has a low content of fine particles which do not contribute to magnetic recording characteristics. As a result, a narrow coercive force distribution is achieved and the powder is suitable for increasing recording density of a magnetic recording medium. The powder containing substituting metal elements can be obtained by: adding an alkali to an aqueous solution containing trivalent iron ions and ions of the metals for partially substituting Fe sites to neutralize the aqueous solution to a pH of 1.5 to 2.5; then adding a hydroxycarboxylic acid; further adding the alkali to neutralize the aqueous solution to a pH of 8.0 to 9.0; washing with water a precipitation of an iron oxyhydroxide containing the substituting metal elements produced; and coating the iron oxyhydroxide containing the substituting metal elements with a silicon oxide and heating the resultant.

The invention discloses a cylindrical-type linear magnetic-gear composite permanent magnet motor, and aims at solving a problem of thrust ripple of a conventional magnetic-gear composite motor. Especially for load disturbance or the starting or braking of a motor, the motor improves the operation stability. The motor comprises a brushless DC linear motor and a linear magnetic gear. The motor is also provided with double mechanical ports, and is in a three-layer gap structure. The motor comprises a main armature winding and an auxiliary damping winding, and can achieve the bidirectional transmission of electromechanical energy. The brushless DC linear motor and the linear magnetic gear respectively employ a cylindrical-type structure for coaxial integration. In other words, a double-stator double-rotor structure is formed through a low-speed rotor (17) and an inner stator (14) which form the magnetic gear, and a high-speed rotor (5) and an outer stator (6) which form the brushless DC linear motor.

The invention provides a magnetic recording medium with both weather resistance and high recording density. The magnetic recording medium of the invention has a magnetic layer comprising at least SmCo-based magnetic fine particles and a hydrophobic binder, wherein the SmCo-based magnetic fine particles include a core composed of SmCo-based nanoparticles and a hydrophilic polymer covering at least a portion of the surface of the core.

The invention discloses a stator permanent magnet type cursor motor structure for reducing positioning force. The structure comprises a primary portion and a secondary portion, wherein an air gap is formed between the primary portion and the secondary portion, a plurality of virtual slots and a plurality of virtual teeth are arranged at the tooth end of each tooth of the primary portion in the moving direction of a motor, the number of the virtual teeth is N1, the number of the virtual slots is N2, the relation of N1 and N2 is N1=N2+1, and the N2 is an odd number larger than 1; a fourth permanent magnet is embedded in the virtual slot right in the middle, and magnetism gathering modules are embedded in the other virtual slots; the magnetizing direction of the fourth permanent magnet is perpendicular to the moving direction of the motor and is towards the air gap; each magnetism gathering module is formed by sequentially and tightly attaching three permanent magnets, wherein the magnetizing direction of the middle permanent magnet is perpendicular to the moving direction of the motor and is towards the air gap, the two permanent magnets on the two sides are relatively magnetized, and the magnetizing direction is the same as the moving direction of the motor; due to the matching of the permanent magnets and the magnetism gathering modules, the positioning force can be reduced, and meanwhile performance indexes such as no-load counter electromotive force, thrust output and the dosage of the permanent magnets are not affected.

The invention discloses a bearingless brushless direct current motor and a control method thereof. The motor is characterized in that: a permanent magnet is uniformly distributed on a surface of a rotor iron core with a Halbach array; both a torque winding and a suspension force winding employ a short pitch winding structure and are wound round a stator tooth together; coils of each two suspension force windings are separated by a stator tooth; through a difference between a given rotating speed and an actual rotating speed and through a PI regulator, a current given value of the torque winding is outputted to control torque winding input current, and rotating speed closed loop control is realized; through a difference between a given rotor radial displacement and a detected actual displacement and through the PI regulator, a suspension force given value is outputted to control suspension force winding input current, and rotor radial displacement closed loop control is realized. By employing the method in the invention, effective control of bearingless brushless direct current motor torque and suspension force are realized, permanent magnetism material is saved, and a motor weight is reduced.

The invention discloses a stator permanent magnet vernier motor with modules evenly distributed at the circumference. The stator permanent magnet vernier motor comprises an inner stator and an outer rotor. The multiple unit modules which are distributed along the circumference of an air gap are fixed to the outer ring of the inner stator. The side walls of every two adjacent unit modules are tightly attached together. Each unit module is composed of a permanent magnet and a magnetizer which are the same in size, wherein the side wall of the permanent magnet and the side wall of the magnetizer are tightly attached together. The permanent magnets are magnetized in a radial mode. The number P of pole-pairs of magnetic field distribution produced by the permanent magnets corresponds to the number of the unit modules and the number of rotor teeth. The magnetizer in each unit module can be replaced by another identical permanent magnet, and after replacement, the two permanent magnets in the same unit module are opposite in magnetizing direction. Due to the mutual cooperation of the unit modules, the limited notch space, near the stator, of the air gap is reasonably utilized, flux density in a magnetic circuit is increased effectively, counter potential in a winding is effectively improved, output torque and power density of the motor are improved, and the size is reduced correspondingly.

The invention relates to an ultrahigh-speed permanent magnet disk motor. The motor comprises a first stator core, a second stator core, a stator winding, an enclosure, a heat dissipation pipeline, a front end cover, a rear end cover, a high-speed rotor and ceramic bearings, wherein the high-speed rotor comprises a high-speed rotor core, permanent magnets, a rotor sheath and a rotor shaft; and thehigh-speed rotor core is installed on the rotor shaft in a sleeving mode, permanent magnet wedge-shaped installing slots are processed in the radial direction to install the permanent magnets, the permanent magnets are installed at the two axial sides of the high-speed rotor core, and the rotor sheath is installed on the high-speed rotor core. The motor has high mechanical strength and is suitablefor ultrahigh-speed running; and moreover, a good heat dissipation system is designed, and the situation that the permanent magnets are demagnetized during ultrahigh-speed running of the disk motor is prevented. The invention not only provides an ultrahigh-speed permanent magnet motor scheme but also discloses a motor assembling method.

The invention provides an electromagnetism transient magnetic loudspeaker, which comprises a vibrating diaphragm, wherein a magnetizer is arranged on the vibrating diaphragm; an electromagnetic device is arranged on an opposite position of the magnetizer, and comprises a coil opposite to the magnetizer, and a magnetic bar; and the magnetic bar penetrates through an inner opening of the coil so as to be opposite to the magnetizer. The weight of the vibrating diaphragm is reduced; due to the removal of a voice coil, the axial movement of the voice coil in a magnetic gap is avoided; an electromagnetic type power structure is adopted, so that compared with an existing permanent magnet, the magnetic density is higher, a sound signal can be performed at high speed; a plane vibrating diaphragm design is adopted, so that voice frequency can be parallely transmitted, the defect of emission of voice frequency of a bowl type vibrating diaphragm is overcome, and the sound signal can be highly positioned; and a nickel ring has the characteristics of magnetization, inoxidizability, acid and alkali corrosion and the like, so that the service life of the loudspeaker is greatly prolonged, the problems that the magnetic force of a permanent magnet is reduced, and the tone quality is affected are solved, and graceful sound with high sound quality, clearness, enriched detail and wonderful layering performance is realized.

The invention discloses a permanent magnet direct-driven vernier motor which comprises an outer rotor, an outer rotor permanent magnet, a stator, a stator permanent magnet, windings, a motor shaft and a bearing, wherein the outer rotor is rotatably connected with the motor shaft through the bearing, the motor shaft is fixedly connected with the stator; the outer rotor permanent magnet is embedded in a rotor yoke; the stator is provided with stator teeth along the circumference, two sides of the top of the stator teeth are respectively provided with notches, a stator slot is formed between the adjacent two stator teeth; the windings are wound on the stator teeth; the end face of the stator permanent magnet is embedded in the notch of the adjacent two stator teeth; the stator permanent magnet and the outer rotor permanent magnet adopt radial magnetization, and the magnetization directions of the stator permanent magnet and the outer rotor permanent magnet are same; clearances are reserved between the stator permanent magnet and the outer rotor, as well as the stator teeth and the outer rotor, and the sum of the number of pole pairs (nr) of the outer rotor permanent magnet and the number of pole pairs (np) of the windings is the number (ns) of the stator teeth. The motor has simplified components and compact structure and can reduce the magnetic flux leakage and improve the motor efficiency.