Japan Servo Co.,ltd.

Hitachi, Ltd.

Hiroshi Hagino

Atushi Yamamoto

Masahiro Horiguchi

Kuniyoshi Nakamura

Takanobu Igarashi

Toshihiko Gotoh

Masahiko Fujita

Hiroshi Saito

Hiroshi Udagawa

Eiitchi Kotake

Kenichiro Igeta

Eiichi Kotake

A magnetic linear position sensor comprises a first yoke which is made of soft magnetic material; a first magnet which is placed at the first yoke, and whose surface is the N-pole and is inclined; a second magnet which is placed at the first yoke, and whose surface is the S-pole and is inclined in a direction opposite to the surface of the first magnet and in a direction facing the surface of the first magnet; a second yoke which is placed at a position opposing the first magnet and the second magnet through an air gap and is made of soft magnetic material; and a magnetoelectric transducer which is placed in the air gap.

Magnetic linear position sensor

The invention relates to a magnetic rotary position sensor that detects the absolute position of a rotation angle as an electric output in a non-contact state with magneto-electric transducers for converting a magnetic flux variation into a voltage. The magnetic rotary position sensor of the invention includes a cylindrical yoke, semi-cylindrical first and second magnets, and magneto-electric transducers. Here, the first and second magnets are disposed on the inside of the yoke to face to each other, and are magnetized in a manner that the N-pole and S-pole face to each other. The magneto-electric transducers are placed in the magnetic field generated by the first and second magnets, rotate against the first and second magnets, and are disposed at a position to detect the magnetic field in the tangential direction of a circle in which the center of the circle coincides with the center of the yoke and the radius of the circle is equal to or larger than half the outline width of the magneto-electric transducers.

Magnetic rotary position sensor

A rotary light coupler comprises a first light emitter and a first light receiver mounted on a fixed body, and a second light emitter and a second light receiver mounted on a rotary body. The first and the second light emitters are arranged to transmit light beams containing signals to the second and the first light receivers respectively, through a rotary mechanism. The first and the second light receivers are placed opposing each other along the direction of the axis of rotation of the rotary body. The first and the second light emitters are placed respectively at the radially outside of the first and the second light receivers. Light axes of the first and the second light emitters are set in such a manner that they direct toward the central portions of the second and the first light receivers respectively and that reflected lights from the second and the first light receivers do not come into the first and the second light receivers respectively. A set of the first light receiver and the first light emitter and a set of the second light receiver and the second light emitter are disposed in such a manner that they do not mechanically interfere with each other when they rotate relatively with each other.

Rotary light coupler

A direct current brushless motor is structured by fixing a ring-shape magnetic rotor to a rotor shaft in one piece by way of the magnet yoke, and by arranging the position of the insulating plate on which the magnetic induction elements for detecting the magnetic field of the rotor magnet, stator windings and the rotor yoke are installed, so as to have the rotor magnet oppose the stator windings across an air gap. The stator windings are composed of delta connection wirings and the windings of each phase are placed on a concentric circle having the rotor shaft at its center and in a position dividing the said circle in equiangular areas. The magnetic induction elements are provided in three with the first, second and third elements being respectively fixed at the positions where their respective phases are advanced by .pi./6 radian in the electric angle from the respective centers of the first phase, second phase and third phase coils. These magnetic induction elements pick up only the plus-side output signals and let the current flow respectively to the aforesaid three-phased stator windings through an amplifier, whereby they form a driving circuit for driving said rotor shaft.

DC Brushless motor and its driving control system

The driving system which drives and rotates a flexible-disc to and from which information is written in and read out by means of a magnetic head. On the top of a driving hub the flexible-disc is attached in a detachable manner, and at the bottom part of the driving hub a driving axle is directly connected coaxially. The lower end of this driving axle itself forms the rotating axle of a direct current magnetic motor. The rotation of this motor is controlled by a rotating speed controlling system so as to rotate at speed identical to any given designated velocity.

Flexible-disc drive spindle assembly with brushless DC motor

An electric motor having a rotor consisting of a disk-shaped multi-polar magnet circumferentially sectioned to have a plurality of magnetic poles, a stator consisting of a pair of superimposed star-shaped flat driving coils, said driving coils being disposed facing said magnet, said driving coils being arranged to be supplied with respective alternating currents having a phase differential of 90.degree. thereby to drive the disk-shaped magnet, said motor further comprising a speed detecting coil having a plurality of radially disposed generating wire elements, said generating wire elements being disposed within a magnetic field of said magnet and being connected in series, whereby a signal having a frequency corresponding to the revolution speed of said disk-shaped magnet is induced in said speed detecting coil.

Growing community of inventors

Omiya, Japan

Hiroshi Hagino