Apparatus (30) and method for determining the location (20) of the source of seismic energy around a well (10) are provided. Multiple seismic receivers (32, 34), each receiver having orthogonal seismic sensors, are axially spaced on a tool (30) which is capable of sending real-time seismic signals to the surface. A method for calculating the source location (20) with respect to the receivers (32, 34) is also provided.

Single well system for mapping sources of acoustic energy

A pulse welding apparatus such as a pulse arc welding apparatus or a short-circuiting arc welding apparatus utilizing pulse discharge, wherein there is provided a pulse current waveform control circuit which feeds a desired pulse arc current to the arc welding power source that supplies pulse arc current to the welding load unit, the circuit being so designed as to effect optimum welding without adjusting or changing the circuit components. Even under various welding conditions or environments, furthermore, it is allowed to prevent defective welding during the arc welding caused by the magnetic blow phenomenon and to prevent defective welding such as undercut or sputtering caused by disturbances in the welding torch. The pulse current waveform control circuit is realized as a microcomputerized digital circuit, and the pulse arc current is controlled by the control operation of a program, in order to realize a desired current control by changing the program but without changing the circuit. By utilizing the memory, furthermore, the optimum welding current waveform parameter or a desired arc length signal is learned during the first welding, and the arc length feedback control or the current waveform control is effected during the second welding using a program prepared with the thus learned welding current waveform parameter or the desired arc length signal as a reference. Thus, the molten mass is prevented from being erroneously removed by the magnetic blow phenomenon, and a change in the arc length is suppressed that is caused by disturbance in the welding torch, contributing to improving the welding quality under various welding environments.

Pulse welding apparatus

A bulk amorphous metal inductive device comprises a magnetic core having plurality of low-loss bulk ferromagnetic amorphous metal magnetic components assembled in juxtaposed relationship to form at least one magnetic circuit and secured in position, e.g. by banding or potting. The device has one or more electrical windings and may be used as a transformer or inductor in an electronic circuit. Each component comprises a plurality of similarly shaped layers of amorphous metal strips bonded together to form a polyhedrally shaped part. The low core losses of the device, e.g. a loss of at most about 12 W/kg when excited at a frequency of 5 kHz to a peak induction level of 0.3 T, make it especially useful for application in power conditioning circuits operating in switched mode at frequencies of 1 kHz or more. Air gaps are optionally interposed between the mating faces of the constituent components of the device to enhance its energy storage capacity for inductor applications. The inductive device is easily customized for specialized magnetic applications, e.g. for use as a transformer or inductor in power conditioning electronic circuitry employing switch-mode circuit topologies and switching frequencies ranging from 1 kHz to 200 kHz or more.

Bulk amorphous metal inductive device

A rotor for an electric motor includes a frame made of a resin and having a cylindrical yoke mounting portion, a base covering one end side of the yoke mounting portion, and a shaft supporting portion located at the center of rotation of the base, all of which are formed integrally with the frame, a rotor yoke mounted on the yoke mounting portion and substantially divided into a plurality of unit yokes, and a plurality of rotor magnets mounted on the yoke mounting portion along the rotor yoke.

Rotor for electric motor

A rotating electric machine comprises a stator and a rotor. In the rotor, numerous slots are formed along a circumferential direction. In the each of slots, a first stator coil and a second stator coil are inserted and insulated by an insulator inserted before inserting the coils in the slots. The insulator encircles the first and second stator coils so as to be formed into an S shape. The center portion thereof extends over the area between the first and second stator coils. One end of the insulator is held between one surface of the center portion of the insulator and the first stator coil. Other end of the insulator is held between another surface of the center portion of the insulator and the second stator coil.

Rotating electric machine

PROBLEM TO BE SOLVED: To realize high performance by preventing a magnet from being demagnetized to the utmost SOLUTION: A penetrating hole 13 is so constituted that spaces 17 are formed in both end portions of a permanent magnet 16 when the magnet 16 is built in the penetrating hole 13 formed in a rotor core 12 Both end portions of the permanent magnet 16 come into contact with air layers of low permeability, so that reverse magnetic flux can be prevented to the utmost from passing the permanent magnet 16 COPYRIGHT: (C)1999,JPO

Permanent magnet type motor

PURPOSE: To decrease core loss and improve efficiency while utilizing effectively the characteristic of a bidirectional silicon steel plate. CONSTITUTION: A constituent laminated steel plate 12 of a stator core is formed by forming a hoop material 13 made of a bidirectional silicon steel plate after a predetermined core shape through punching. The easy magnetization directions of the hoop material 13 are the longitudinal direction of its rolling direction and the orthogonal direction thereto (the ones shown by solid line arrows), and its hard magnetization direction are the ones forming respectively angles of 45 deg. with the easy magnetization directions (the ones shown by two-dot chain line arrows). In each laminated steel plate 12, the core widths in its hard magnetization directions are set larger than the ones in its easy magnetization directions.

Core and rotor core for rotating machine

The effects of shrink fitting on the magnetic properties of iron cores are investigated in order to simulate the magnetic behavior of iron cores mounted in motor frames. Shrink fittings, of course, decrease permeability and increase effective magnetostriction and magnetic loss. It is well known that the magnetostriction increment and the permeability decrement are explained by the increase of magnetoelastic energy due to compressive stress by shrink fitting. The magnetic loss increases, however, cannot be explained by this energy. We demonstrate experimentally that the magnetic loss increases result from mechanical work due to the magnetostrictive movement of the iron core under compressive stress. © 1998 Scripta Technica, Electr Eng Jpn, 123(1): 15–22, 1998

https://www.jstage.jst.go.jp/article/ieejfms1990/117/3/117_3_311/_pdf

Effects of External Stress on Magnetic Properties in Motor Cores

PURPOSE: To remarkably reduce noise by a method wherein, on the outside of a wound core formed by winding a grain oriented silicon steel strip, magnetic material whose magnetostriction is lower than that of said strip is wound so as to constitute a combined iron core, and the sectional area of the magnetic material of low magnetostriction is made equal to 10-50% of the sectional area of the total iron core. CONSTITUTION: A wound core 11a formed by winding a grain oriented silicon steel strip 11a is arranged on the inside part; magnetic material 12a of low magnetostriction is wound around the outside of the wound core 11a so as to constitute a combined iron core, the sectional area of the iron core formed by winding the magnetic material 12a is made equal to 10-50% of the sectional area of the total iron core. Hence, in a magnetic flux waveform wherein a fundamental wave contains higher harmonics, the greater part of the fundamental wave component is loaded on the grain oriented silicon steel strip, and higher harmonic components are loaded on the magnetic material of low magnetostriction, thereby restraining the degradation of magnetic characteristics. Hence a low noise transformer iron core can be obtained without deteriorating magnetic characteristics. COPYRIGHT: (C)1991,JPO&Japio

Iron core of transformer

PURPOSE:To make uniform the temperature distribution of each part of an iron core by a method wherein the generated heat corresponding to the quantity of radiant heat coming from the surface part of the iron core is added by increasing the generated loss of the surface part of the iron core. CONSTITUTION:Each of magnetic material bodies 13 is wound around between wound layers of the amorphous magnetic alloy thin plate 12 on the outer circumferential surface of a wound core 11 and the wound core 11 located adjoining to the outer circumferential surface of the wound core 11. The magnetic material body 13 has a large loss generating value, and a silicon steel plate (Curie point of approximately 700-800 deg.C, average thickness of approximately 0.35mm), which has the Curie point higher than that of the amorphous magnetic alloy thin plate 12 (Curie point of approximately 500-550 deg.C), can be used for said magnetic material body 13. Then, two wound cores 11 are arranged, and an exciting coil 14 is wound (temporary winding) on the leg part located outside each wound cores 11 in such a manner that their winding direction is reversed each other. When an annealing is performed for the purpose of removing the distortion of the wound cores 11, the exciting coil 14 is connected to a high frequency AC power source 16 using a change-over switch 15, and a high frequency AC current is applied to the exciting coil 14 by adjusting voltage using a voltage adjuster 18. When an AC current is applied to the exciting coil 14, heat is generated on the amorphous magnetic alloy thin plate 12 and the magnetic material body 13.

Yamada Kazuo

Papers

Permanent magnet type motor

Core and rotor core for rotating machine

Effects of External Stress on Magnetic Properties in Motor Cores

Iron core of transformer

Manufacture of iron core