Tachogenerator having a magnetoresistance stator coil
AssigneeVictor Company of Japan, Ltd.
InventorsNaoki Akiyama, Kenichi Kitamura, Eiichi Kotake
Life of this patent
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Abstract
A tachogenerator has a magnetoresistance film coil formed on a stator surface along a circular path concentric with a rotor axis. The coil has a spatially periodic structure, with multiple spaced-apart lateral components series connected with longitudinal components. The stator surface is opposite to a rotor surface having multiple equiangularly spaced magnetic pole faces with alternately opposite polarities. Current passed through the coil develops voltage variations. Undesirable small voltage variations resulting from manufacturing tolerances are averaged to zero at the coil output terminals.
Claims13
A tachogenerator comprising:
- a rotor member having an axis, a stator member coaxial with the axis of the rotor member;
- one of said members having multiple equiangularly spaced-apart, alternately oppositely magnetized pole faces lying along a first path coaxial with the axis in a first surface;
- and
- the other member comprising an electrically insulative stationary support having a second surface opposed to said first surface, and a coil of magnetoresistance material formed on said second surface, said coil being arranged on said second surface along a second path extending concentric with said axis over an arc of at least 180 degrees in a spatially periodic structure having multiple angularly spaced-apart lateral components connected in series with intermediate longitudinal components, the lateral components and the multiple pole faces being arranged so that the lateral components cut flux from the pole faces as the rotor turns about the axis.
A tachogenerator comprising:
- a rotor member having an axis, a stator member coaxial with the axis of the rotor member;
- one of said members having multiple equiangularly spaced-apart, alternately oppositely magnetized pole faces lying along a first path coaxial with the axis in a first surface;
- the other member comprising an electrically insulative stationary support having a second surface opposed to said first surface, and a coil of magnetoresistance material formed on said second surface, said coil being arranged on said second surface along a second path extending concentric with said axis over an arc of at least 180 degrees in a spatially periodic structure having multiple angularly spaced-apart lateral components connected in series with intermediate longitudinal components;
- and
- said pole faces and coil being arranged so that the lateral components and the multiple pole faces cause the lateral components to cut flux from the pole faces as the rotor turns about the axis and changes in resistance occur in the radial components and are combined in response to turning of the rotor to produce a total resistance change having a first frequency proportional to the rotor rotation speed and so that there is induced in the radial components voltages resulting from electromotive forces produced by magnetic field strength rates of changes on the coil, said induced voltages combining to produce a net voltage having a frequency that is one-half of said first frequency.
Dependencies are inferred from the claim text.