191results about How to "Avoid Flux Leakage" patented technology

A write element for use in perpendicular magnetic recording. The write element including a write pole and a self aligned wrap around shield that can have a trailing shield gap thickness that is different from its side shield gap thickness. The materials making up the trailing shield gap and the side shield gaps can be different materials or can be the same material deposited in two different steps. The side or wrap around portions of the trailing shield can extend down to the level of the leading edge of the write pole or can terminate at some point between the levels of the leading and trailing edge to form a partial wrap around trailing shield.

A write element for use in perpendicular magnetic recording. The write element including a write pole and a self aligned wrap around shield that can have a trailing shield gap thickness that is different from its side shield gap thickness. The materials making up the trailing shield gap and the side shield gaps can be different materials or can be the same material deposited in two different steps. The side or wrap around portions of the trailing shield can extend down to the level of the leading edge of the write pole or can terminate at some point between the levels of the leading and trailing edge to form a partial wrap around trailing shield.

An electromagnetic steel plate forming member provides the two magnet holes for inserting therein the two permanent magnets per pole along the V-shape, which are provided in the region of the radial pole pitch lines OP provided in the rotor core at the predetermined pole pitch angle θ, one magnet hole is displaced in a direction apart from the center line OC of the pole pitch lines OP, and the other magnet hole is displaced in a direction approaching to the center line OC of the pole pitch lines OP.

A magnetic circuit having a dual magnet, a speaker and a vibration generating apparatus using the same are provided. The magnetic circuit includes a magnetic gap having a small magnetic loss and an increasing magnetic flux density, in which a uniform distribution of a line of magnetic force can be realized on yoke surfaces facing each other. The speaker includes lower and upper magnets which are spaced so that mutually identical polarities oppose each other; a first yoke integrally having a loop-type circulating circuit portion extended from the lower magnet to the upper magnet and an extension portion which is extended perpendicularly upwards from the lower magnet; a second yoke which connects between the lower and upper magnets and forms a magnetic gap between the second yoke and the extension portion of the first yoke; a coil disposed in the magnetic gap and wound around a bobbin; a frame which is extended from the first yoke; a vibrating diaphragm generating an acoustic sound in correspondence to a drive signal; a damper limiting a vibration range of the bobbin; and a center cap covering the bobbin.

A magnetic head for use in a perpendicular recording system having a novel shield structure that provides exceptional magnetic shielding from extraneous magnetic fields such as from a write coil, shaping layer or return pole of the write head. The magnetic head includes a write pole, a return pole and a magnetic shield that is magnetically connected with the return pole near the ABS and extends toward the write pole. The shield is formed with a notch at its edge closest to the write pole. The notch assures adequate physical, magnetic, and electrical separation between the write pole and the shield, while allowing un-notched portions of the shield to provide additional magnetic shielding.

A motor that reduces a cogging torque and rotates at a high speed is presented. The motor comprises: a shaft, a plurality of core blocks coupled to the shaft, a plurality of permanent magnets inserted into each of the core blocks, and an aligning unit, coaxial with the shaft, and disposed between the shaft and the core blocks. The core block includes a plurality of core sheets each having at least a pair of flux barriers formed to be symmetrical to each other about a line of symmetry. A first rib lies along the line of symmetry and a separate anti-deformation rib is positioned within each of the pair of flux barriers. Accordingly, a skew process for a rotor is facilitated. An anti-deformation rib within the flux barrier provides structural integrity for the core block. Accordingly, when the rotor is rotated with a high speed, a bridge is prevented from being deformed.

A motor comprising: a rotor including a permanent magnet type rotor unit having a plurality of permanent magnets and a reluctance type rotor unit having a plurality of magnetic salient pole portions and a plurality of slits for preventing flux leakage, the rotor units being coupled to each other in an axial direction; and a stator for generating a field for driving the rotor. Elongated holes for preventing the short-circuit of magnetic fluxes are arranged near edges of the permanent magnet of the permanent magnet type rotor unit. The elongated holes or notches are arranged within a range defined so that 0.95α≦θ≦1.05α with α={(360 / S)−R} / 2 (degrees), where θ is an angle formed between a magnetic pole boundary and a center of the elongated hole or the notch in a forward direction of rotation of the rotor with respect to a center of a rotating shaft, R is an angle formed by a tooth width of the stator with respect to the center of the rotating shaft, P is the number of rotor poles, and the number of stator slots is S=3P / 2.

A magnetic head for use in a perpendicular recording system having a novel shield structure that provides exceptional magnetic shielding from extraneous magnetic fields such as from a write coil, shaping layer or return pole of the write head. The shield structure is constructed to have a bottom or leading surface that is generally coplanar with the bottom or leading surface of the shaping layer, but all or a portion of the shield structure is not as thick as the shaping layer so as to have a top surface that does not extend to the same elevation (in a trailing direction) as that of the shaping layer. Making the shields extend to a lower level than the shaping layer improves magnetic performance by reducing flux leakage from the write pole, and also provides manufacturing advantages, such as during the manufacturing of the write pole. These manufacturing advantages include the advantage of having the shields covered with a protective layer of, for example, alumina during the ion milling of the write pole.

The invention relates to a two-stage series pressurization direct-driven centrifugal air compressor of a fuel cell engine. The two-stage series pressurization direct-driven centrifugal air compressor comprises end covers, a spindle, volutes, impellers, a rotor, a stator and a driver. The spindle is supported by a left-end radial supporting air foil bearing, a left-end radial supporting air foil bearing bush, an air foil axial thrust bearing and a right-end radial supporting air foil bearing, wherein the left-end radial supporting air foil bearing and the left-end radial supporting air foil bearing bush are arranged on the left side, and the air foil axial thrust bearing and the right-end radial supporting air foil bearing are arranged on the right side of the spindle. The left-end radial supporting air foil bearing bush is arranged on the outer side of the spindle in a surrounding manner. The left-end radial supporting air foil bearing is fixed to the outer side of the left-end radial supporting air foil bearing bush. The air foil axial thrust bearing is fixed to the outer side of the spindle in a bush form. The right-end radial supporting air foil bearing is fixed to the outer side of the air foil axial thrust bearing. Compared with the prior art, the two-stage series pressurization direct-driven centrifugal air compressor is more suitable for the air inlet pressurization scene of the fuel cell engine with the high oilless air inlet requirement, and the durability and reliability of the air compressor of the fuel cell engine can be improved.

A reciprocating motor and a reciprocating compressor having the same make the manufacture of a stator easier and therefore reduce manufacturing costs by configuring the stator such that an inner stator positioned inside the mover and an outer stator positioned outside the mover are integrally formed, or by making the inner and outer circumferential surfaces of the stator have the same curvature. Also, no gap is generated between the inner stator and the outer stator, and this prevents magnetic leakage, thereby improving the performance of the motor. Also, the use of magnets can be reduced by omitting magnets between stator blocks, and therefore manufacturing costs can be reduced, when compared to the efficiency of the motor.

Disclosed is a variable differential mount apparatus using a Magnetorheological Elastomer (MRE). The apparatus includes a core, a coil, a plurality of MRE supports, and a magnetic path formation member. The core has a plurality of arms disposed thereon. The coil is wound on the plurality of arms, respectively. The plurality of MRE supports are disposed to face the plurality of arms, respectively. The magnetic path formation member is disposed outside the plurality of MRE supports. More specifically, a current is applied to coil to vary the degree of stiffness of the variable differential mount based on a particular driving condition to allow for increased handling and comfort.

The invention relates to an electric excitation permanent magnet switch, a reluctance motor for the electric excitation permanent magnet switch and an electric excitation method. In the electric excitation permanent magnet switch, two magnetic poles of a permanent magnet are respectively connected with both ends of an iron core on which magnet exciting coils are wound by two soft magnets; and salient poles are arranged on the soft magnets. In the reluctance motor, the switch is used as basic components of a stator and a rotor, and the two magnetic salient poles of each component are arranged in an axial direction; the salient poles of the stator component and the rotor component are arranged oppositely, and air gaps are reserved between the salient poles; and the magnet exciting coils of the stator component and the rotor component at the axial symmetrical position are connected in series or in parallel and then are used as a phase line respectively to be connected to an excitation control power supply. The invention also provides a combination motor formed by connecting motor monomers by using a shaft in a rotary and dislocation mode and a method for the simultaneous diphase electric excitation of the stator component. The switch and the motor save energy, and have low magnetic loss and high magnetic efficiency; and the combination motor with the diphase electric excitation realizes the subdivision of stepper angles, and improves running stability, control accuracy and output power.

The invention provides a magnetostriction-based precise feeding driving device. The device comprises a magnetic-induced driving shaft body, and a loop magnetic field generating device which sleeves the magnetic-induced driving shaft body is rotated relative to the magnetic-induced driving shaft body; an excitation magnetic field for enabling a magnetic-induced displacement driving mechanism to drive and displace is arranged between the loop magnetic field generating device and the magnetic-induced driving shaft body; an elastic end cover part of the magnetic-induced driving shaft body is elastically deformed only in the displacement output direction. The invention also provides a processing machine tool equipped with the magnetostriction-based precise feeding driving device. According to the magnetostriction-based precise feeding driving device, the structure is simple; the mass is light; the magnetism between a permanent magnet and / or an electromagnet is utilized to generate processing acting force for rotating and reciprocating vibrating; the control precision is high; the response frequency is high; a conductive sliding ring is removed, so that the reliability of the device is improved; the magnetostriction-based precise feeding driving device is particularly suitable for hard and brittle materials and metals which are difficultly processed such as titanium.

A main pole has a top surface including a first portion and a second portion. The main pole has a bottom end including a third portion and a fourth portion. Each of the first and third portions has a first end located in a medium facing surface. The first portion is inclined relative to the medium facing surface and a first virtual plane that passes through the first end and is perpendicular to the medium facing surface and to the direction of travel of a recording medium. The third portion is inclined relative to the medium facing surface and a second virtual plane that passes through the first end and is perpendicular to the medium facing surface and to the direction of travel of the recording medium. The first portion is smaller than the third portion in length in a direction perpendicular to the medium facing surface.

A magnetic head for use in a perpendicular recording system having a novel shield structure that provides exceptional magnetic shielding from extraneous magnetic fields such as from a write coil, shaping layer or return pole of the write head. The magnetic head includes a write pole, a return pole and a magnetic shield that is magnetically connected with the return pole near the ABS and extends toward the write pole. The shield is formed with a notch at its edge closest to the write pole. The notch assures adequate physical, magnetic, and electrical separation between the write pole and the shield, while allowing un-notched portions of the shield to provide additional magnetic shielding.

Disclosed is an electric power generating apparatus. The electric power generating apparatus includes a casing that is made of a nonmagnetic material and has an outer surface and an interior space, a guide shaft that is made of a nonmagnetic material and provided in the interior space while being supported by the casing, a permanent magnet provided to the guide shaft so that the permanent magnet is capable of being reciprocated, a coil provided on an outer circumference of the interior space, a shield case to cover the outer surface of the casing, the shield case being made of a magnetic material, and an electric circuit unit to output an electric energy generated in the coil by reciprocating the permanent magnet.

An object is to provide an electromagnetic stirrer that can provide an excellent stirring force more than before. An electromagnetic stirrer has a vertical electromagnetic field generating coil (1) vertically and circumferentially provided on the outer side of a container (5), and a rotational electromagnetic field generating coil (2) provided on the outer side of the vertical electromagnetic field generating coil (1), in which an iron core (3) is inserted between the vertical electromagnetic field generating coils (1) and between the rotational electromagnetic field generating coils (2), the iron core (3) being formed of a magnetic material with magnetic isotropy and having comb teeth 3a extended to the inner surface of the vertical electromagnetic field generating coil (1).

An inner-rotor-type heat dissipating fan comprises a fan housing, a seal casing, an inner-rotor-type motor, an impeller and a circuit board. The fan housing includes an outer frame portion and a motor casing. The seal casing is a hollow housing made of magnetically conductive material. One end of the seal casing forms a connecting portion coupling to the motor casing. The inner-rotor-type motor is mounted inside the seal casing. The impeller is coupled to the inner-rotor-type motor and outside the seal casing. The circuit board is electrically connected to the stator. By this configuration, rotation stability of the impeller is enhanced by the inner-rotor-type motor, airflow generated by rotation of the impeller is effectively concentrated and guided by the fan housing and a sealing effect for avoiding magnetic flux leakage is provided by the seal casing. Consequently, heat dissipating efficiency is enhanced.

Deformation and vibration of claw magnetic poles in rotor are reduced. A rotor includes: a rotor coil 15 for generating a magnetic flux by applying a current; a pole core comprised of a first pole core body 19 and a second pole core body 20 that are disposed so as to cover the rotor coil 15, each being provided with claw-shaped claw magnetic poles 21, 22 engaging with each other; and a magnet assembly 25 composed of a magnet 23 for reducing leakage of magnetic flux and a magnet-holding member 24 for supporting the magnet 23 on the claw magnetic poles 21, 22. Center of gravity 25G of the magnet assembly 25 is located on the base part side nearer than the center of the claw magnetic poles 21, 22.

The invention provides a damping hollow rod with a multistage energy dissipation mechanism, and belongs to the technical field of structure vibration control. The damping hollow rod comprises a hollowrod body, permanent magnets, conductor pieces, rotating springs, pull-press springs, a sliding block, balls, colliding rings, a guide rod, round rubber gaskets, inner end plates, fixed rods, rubber layers and stiffening ribs. According to the damping hollow rod, the eddy-current damping technology is combined with other passive vibration attenuation technologies, and the multistage energy dissipation mechanism is achieved. When small-amplitude vibration happens to the structure, eddy current energy dissipation units and rotating spring energy dissipation units achieve energy dissipation together; when large-amplitude vibration happens to the structure, the eddy current energy dissipation units and colliding energy dissipation units achieve energy dissipation together; and the different energy dissipation units achieve cooperative energy dissipation work, the energy dissipation control effect is obviously enhanced, meanwhile, damping parameters can be conveniently adjusted, and magnetleaking of magnetic circuits is basically avoided.

A coil surrounding only the tip of nozzles of a plastic extruding die is provided. By passing a high frequency current through the coil to selectively heat only the tip of the nozzles. Further, in a plastic extruding die in which a high frequency current is passed through a coil provided around nozzles to heat the periphery of the nozzles, the coil is formed of a conductor tube through which a coolant is caused to flow.

A flux concentration-type motor includes a ring-shaped stator, in which coils are wound on a plurality of teeth radially arranged; and a rotor, located at the center of the stator, having a plurality of magnets arranged in a circumferential direction such that poles, having the same polarity, of the magnets face each other, and rotated by the interaction with the stator, so as to prevent the leakage of magnetic flux of the magnets, thereby improving the torque compared to a conventional surface mounted permanent magnet-type motor having the same volume, reducing the production costs, and facilitating the miniaturization of products.

In a vehicle AC generator, the rotor has two pole pieces that axially enclose a field winding, while a tubular stacked-lamination core formed of axially stacked magnetic laminations is mounted with its inner circumference in contact with outer circumferences of the pole pieces. A plurality of axially extending elongated permanent magnets each magnetized in the circumferential direction are implanted in the stacked-lamination core, with adjacent permanent magnets polarized in opposite directions, so that axially extending circumferentially alternating N and S rotor poles are formed at the outer circumferential surface of the stacked-lamination core by the magnetic flux of the field winding.