Hitachi Metals, Ltd.

Kyohei Aimuta

Masahiro Mita

Osamu Shimoe

Yasuyuki Okada

Shigeho Tanigawa

Masahiro Masuzawa

Chiharu Mitsumata

Rihito Kagawa

An angle detection apparatus comprising a magnet rotor having a multi-pole segment magnet, and a magnetic sensor for detecting the direction of a magnetic flux generated from the multi-pole segment magnet; the multi-pole segment magnet having pluralities of magnetic poles along the rotation direction of the magnet rotor, the magnetic sensor comprising a magnetosensitive plane having pluralities of spin-valve, giant-magnetoresistive devices each having a pinned layer having a fixed magnetization direction and a free layer having a magnetization direction rotating in response to the magnetic flux direction; and the magnetic sensor being positioned relative to the magnet rotor, such that the magnetosensitive plane crosses the magnetic flux, with perpendicular magnetic flux density components having different amplitudes on the magnetosensitive plane.

Angle detection apparatus and position detection apparatus

An apparatus for detecting a rotation angle using a magnet rotor comprising a magnet having 2N poles, wherein N is a natural number, and a sensor device for detecting the direction of a magnetic flux from the magnet rotor, at least one of two output voltages obtained in radial and rotational directions by the sensor device being multiplied by a correction coefficient, and the rotation angle being calculated from the two corrected output voltages to increase the detection accuracy of the rotation angle.

Rotation-angle-detecting apparatus, rotating machine and rotation-angle-detecting method

A rotation-angle-detecting apparatus comprising a magnet rotor having 4 or more magnetic poles on the surface, and sensor device for detecting magnetic flux from the magnet rotor, and an electronic circuit for outputting a signal representing the rotation angle of the magnet rotor using pluralities of signals obtained from the sensor device, the sensor device having pluralities of spin-valve, giant-magnetoresistive devices for outputting two or more different phase signals from a rotating magnetic field near the rotating magnet, each spin-valve, giant-magnetoresistive device having a pinned layer and a free layer, the magnetization direction of the pinned layer being fixed, and the magnetization direction of the free layer rotating depending on a magnetic field direction, pluralities of the spin-valve, giant-magnetoresistive devices comprising a first spin-valve, giant-magnetoresistive device having a reference magnetic-field-sensing direction, and a second spin-valve, giant-magnetoresistive device having a magnetic-field-sensing direction different from that of the first spin-valve, giant-magnetoresistive device.

Rotation-angle-detecting apparatus, rotating machine, and rotation-angle-detecting method

A rotation-angle-detecting apparatus comprising a magnet rotor, a magnetic sensor detecting the direction of magnetic flux from the magnet rotor, a correction circuit, and an angle-calculating circuit, the magnetic sensor having bridge circuits X and Y each comprising four connected magnetoresistive devices, each magnetoresistive device comprising a spin-valve, giant-magnetoresistive film, the correction circuit calculating difference (Vx&#x2212;Vy) and sum (Vx+Vy) from the output voltage Vx of the bridge circuit X and the output voltage Vy of the bridge circuit Y, and making their amplitudes equal to each other, and the angle-calculating circuit determining the rotation angle of the rotor by arctangent calculation from a signal (Vx&#x2212;Vy)' and a signal (Vx+Vy)&#x2032; supplied with the same amplitude from the correction circuit.

Rotation-angle-detecting apparatus

This invention provides a soft magnetic yoke-integrated bonded magnet in which a soft magnetic yoke has been integrally compression molded in such a state that the soft magnetic yoke is engaged in a joined face formed by bringing a binding material-containing magnetic powder into contact with a binding material-containing soft magnetic powder. The soft magnetic yoke part and the bonded magnetic part are constructed so that, when the soft magnetic yoke part and the bonded magnet part are compression molded separately from each other, the spring back level is identical upon the release of the compression force.

Growing community of inventors

Kumagaya, Japan

Kyohei Aimuta