33results about How to "Shorten the length of the magnetic circuit" patented technology

A thin-film magnetic head comprises a medium facing surface, a bottom pole layer, a top pole layer, a recording gap layer, and a thin-film coil. The bottom pole layer and the top pole layer are coupled to each other via a coupling portion located away from the medium facing surface. The coupling portion has an end face facing toward the medium facing surface. The end face includes a curved surface convex toward the medium facing surface. The thin-film coil has a conductive layer of three turns disposed around the coupling portion. The first turn of the conductive layer from an inner side thereof includes a portion disposed between the end face of the coupling portion and the medium facing surface. This portion has a minimum width of the conductive layer at a position on a virtual line connecting the end face of the coupling portion and the medium facing surface in the shortest distance, and increases in width with distance from the virtual line.

A thin-film magnetic head comprises: a first magnetic layer and a second magnetic layer each of which includes a magnetic pole portion, the first and second magnetic layers being magnetically coupled to each other at a distance from the medium facing surface ABS; a gap layer provided between the first and second magnetic layers; and a thin-film coil at least a part of which is disposed between the first and second magnetic layers. The second magnetic layer has a pole portion layer and a yoke portion layer. The pole portion layer has a saturated magnetic flux density equal to or greater than that of the yoke portion layer. The yoke portion layer includes: a first layer and a second layer, of which the first layer is in contact with the first magnetic layer and a surface of the pole portion layer that is closer to the gap layer; and the second layer is in contact with the first layer, the rear end surface of the pole portion layer and both side surfaces of the pole portion layer in the width direction.

A thin-film magnetic head comprises a bottom pole layer, a top pole layer, a recording gap layer, and a thin-film coil. The thin-film magnetic head further comprises a coupling portion which is located away from an air bearing surface and establishes coupling between the bottom pole layer and the top pole layer. The coupling portion has an end face facing toward the air bearing surface. The end face includes a curved surface convex toward the medium facing surface. A part of the thin-film coil, which is disposed between the end face and the air bearing surface, has a minimum width of the thin-film coil in a position on a virtual line connecting the end face and the air bearing surface in the shortest distance, and increases in width with distance from the virtual line.

The challenge to be solved by the present invention is the miniaturization of a 1-300 W class of motor. This can be achieved by using a hollow-cylinder shaped anisotropic bonded magnet magnetized in a 4-pole configuration. The anisotropic bonded magnet has a maximum energy product approximately 4 times greater than the conventional sintered ferrite magnets. The use of a 4-pole configuration shortens the magnetic path length of the individual magnetic circuits and the magnetic force contributing to the torque is increased. When the torque is kept the same as in the conventional motor, the length of the electromagnetic rotor core and the axial magnet length can be reduced. In this fashion, 1-300 W class motors can be reduced in size.

A return path section includes first and second yoke portions and first, second and third columnar portions. The first and second yoke portions and the first columnar portion are located on the same side in the direction of travel of the recording medium relative to a wave guide core. The second and third columnar portions are located on opposite sides of a plasmon generator and connected to a shield. The first yoke portion connects a main pole to the first columnar portion. The second yoke portion connects the first columnar portion to the second and third columnar portions. A coil is wound around the first columnar portion.

A thin-film magnetic head includes an insulation gap, first and second yoke layers with first and second ends, respectively, the first ends constituting magnetic poles separated from each other by the insulation gap, the second ends being magnetically coupled with each other, and a coil conductor constituted by a plurality of single layer turns, for generating magnetic field and applying the generated magnetic field into the first and second yoke layers. Each turn of the coil conductor includes a first section, a second section with one end coupled with one end of the first section, and a third section with one end coupled with the other end of the second section. The third section travels to pass outside of the first yoke layer in parallel with the surface of the first yoke layer, and to extend over the first yoke layer.

A magnetic head includes a coil, a main pole, a write shield, first and second yoke layers, and first and second coupling parts. The first yoke layer is located on the trailing side relative to the main pole whereas the second yoke layer is located on the leading side relative to the main pole. The first coupling part couples the main pole and the first yoke layer to each other. The second coupling part couples the first yoke layer and the second yoke layer to each other. The first coupling part includes a plurality of first magnetic path portions, and the second coupling part includes a plurality of second magnetic path portions. The coil includes one winding portion extending to pass around the first and second magnetic path portions alternately in a zigzag manner.

A thin-film magnetic head comprises a bottom pole layer, a top pole layer, a recording gap layer, and a thin-film coil. The thin-film coil is wound in a helical manner around the top pole layer while the coil is insulated from the bottom pole layer and the top pole layer. The thin-film coil includes a plurality of inner conductor portions, a plurality of outer conductor portions, and a plurality of connecting portions that connect the inner conductor portions to the outer conductor portions. The inner conductor portions are disposed between the bottom pole layer and the top pole layer. The outer conductor portions are disposed on a side opposite to the inner conductor portions, the top pole layer being disposed in between. A thin insulating film is only provided between adjacent ones of the inner conductor portions.

A magnetic head includes first to third coils, a main pole, a write shield, first and second yoke layers, and first and second coupling parts. The first and second yoke layers are magnetically connected to the write shield. The first yoke layer is located on the leading side relative to the main pole, whereas the second yoke layer is located on the trailing side relative to the main pole. The first coupling part magnetically couples the main pole and the second yoke layer to each other. The second coupling part magnetically couples the first yoke layer and the second yoke layer to each other. The first coil is wound around the first coupling part, whereas the second and third coils are wound around the second coupling part.

The invention relates to an energy and material saving magnetic ballast or transformer. The magnetic ballast or transformer comprises a magnetic core body and a coil; the magnetic core body is formed by buckling upper and lower E crossed magnetic core bodies which have systematical structures and a magnetic circuit of each magnetic core body is closed; in the upper E crossed magnetic core body or the lower E crossed magnetic core body, the central part is provided with a magnetic core body boss; the periphery corresponding to the magnetic core body boss is provided with vertical magnetic core body side walls; wire insertion grooves are formed between the magnetic core body side walls and the periphery corresponding to the magnetic core body boss; the grooves have groove bottoms; the upper ends of the grooves are provided with openings; and the coil is inserted into whole wire insertion grooves which are formed by bucking the upper and lower E crossed magnetic core bodies which have systematical structures. Compared with the conventional magnetic ballast or transformer, the energy and material saving magnetic ballast or transformer has the advantages that enamelled wires and silicon sheets are saved, electric resistance and magnetic loss are reduced, and energy consumption is reduced.

A method for producing a magnetic head, including the steps of forming a magnetic body on a substrate, the magnetic body including a principal plane facing the substrate and a rear plane opposite to the principal plane; applying a beam to the rear plane of the magnetic body and forming a portion defining a hole extending from the rear plane to the principal plane; forming a magnetic gap in the hole; and separating the magnetic body and the magnetic gap from the substrate and forming medium facing surface substantially coplanar with the principal plane.

On a surface of a bottom pole, a write gap film and first magnetic material film having a high saturation magnetic flux density are formed, and the first magnetic material film is etched to remain a portion extending from an air bearing surface to a throat height zero reference position and a first non-magnetic film is formed in a removed portion. The first non-magnetic material film is polished to obtain a flat surface which is coplanar with a surface of the first magnetic material film. A second magnetic material film having a high saturation magnetic flux density is formed on the flat surface. The second magnetic material film, first magnetic material film, write gap film and bottom pole are partially removed by RIE using a mask formed on the flat surface.

A thin-film magnetic head comprises a bottom pole layer, a top pole layer, a recording gap layer, and a thin-film coil. The thin-film coil is wound in a helical manner around the top pole layer while the coil is insulated from the bottom pole layer and the top pole layer. The thin-film coil includes a plurality of inner conductor portions, a plurality of outer conductor portions, and a plurality of connecting portions that connect the inner conductor portions to the outer conductor portions. The inner conductor portions are disposed between the bottom pole layer and the top pole layer. The outer conductor portions are disposed on a side opposite to the inner conductor portions, the top pole layer being disposed in between. A thin insulating film is only provided between adjacent ones of the inner conductor portions.

A thin-film magnetic head includes a bottom pole layer, a top pole layer, a recording gap layer, and a thin-film coil. The bottom pole layer has first to fifth layers. The third layer and the fifth layer constitute a coupling portion for establishing magnetic coupling between the bottom pole layer and the top pole layer. The thin-film coil has first to fifth layer portions each of which is made of a flat conductive layer of a single turn. The first to fifth layer portions are laminated, and connected in series to each other. The coupling portion has an end face facing toward the air bearing surface. The end face includes a curved surface convex toward the medium facing surface.

The invention discloses a transverse flux switching reluctance motor and a control method thereof. The motor section comprises stator cores, rotor cores, stator windings, non-magnetic rotor sleeves and bearings. A stator comprises Ns stator cores and Ns circular armature windings embedded in the stator core structures, Ns stator windings can be in symmetrically grouping at the circumference, composing an m-phase winding, wherein Ns=2mk, k is an arbitrary integer greater than 1. A rotor comprises Nr rotor cores, and each rotor core is uniformly disposed on the non-magnetic rotor sleeve at the circumference, wherein Nr=Ns+ / -2k. Each phase of winding is independently energized with direct current in sequence according to the calculated conduction and the extinction angle, forming a reluctance torque of the motor to drive the rotation of the motor. The transverse flux motor is composed of the arrangement of the stator and the rotor and the main flux path, making the inexistence of mutual inductance in the motor. Furthermore, combined with electrification sequence and method of each phase of the winding of the motor, the change of the reluctance of motor for driving of the rotation of motor is achieved, and the power density of motor is raised.

The invention provides a small type current clamp for the checking of a live line measurement scene, wherein one end of a current clamp body is arranged in a clamp body jacket; the other end of the current clamp body stretches out of the clamp body jacket; a clamp body embedment is arranged at an out-stretching current clamp head; a clamp body sliding chute in the same direction with a clamp body is formed in the middle part of an out-stretching end of the current clamp body; the interior of the current clamp head is provided with a measurement magnetic core component which can move left and right along the clamp body sliding chute; and a dynamic magnetic arm and a static magnetic arm of the component are closed to form a closed magnetic circuit and are opened to cause the whole closed magnetic circuit to be disconnected. With the adoption of the small type current clamp for the checking of the live line measurement scene, the problem that due to large volume, the current clamp of the prior art is inapplicable for small operation space is solved; moreover, the working position of the measurement magnetic core component extends to the current clamp head from the interior of the current clamp body; in such a way, the length of a magnetic path in the current clamp body is decreased; under the premise of guaranteeing a proportion between the cross section of the magnetic path and the magnetic path length, the measurement precision of the current clamp is guaranteed; and therefore, the small type current clamp for the checking of the live line measurement scene is applicable for the field of various live line measurements.

A return path section includes first and second yoke portions and first, second and third columnar portions. The first and second yoke portions and the first columnar portion are located on the same side in the direction of travel of the recording medium relative to a wave guide core. The second and third columnar portions are located on opposite sides of a plasmon generator and connected to a shield. The first yoke portion connects a main pole to the first columnar portion. The second yoke portion connects the first columnar portion to the second and third columnar portions. A coil is wound around the first columnar portion.