Index position detector for spindle motor and motor apparatus including the same
AssigneeAlps Electric Co., Ltd.
InventorMikio Sekine
Life of this patent
Estimating the term…
Abstract
An index position detector for a spindle motor includes a rotor magnet which is provided on an inner surface of a flange portion of a rotor yoke. A window portion is formed in the flange portion such that a part of the rotor magnet faces outwardly. An inductor is disposed in a stator section and opposes the periphery of the flange portion. The inductor detects a magnetic flux of the rotor magnet via the window portion.
Claims28
An index position detector for a spindle motor, comprising:
- a circuit board disposed above a mount;
- a rotor yoke supported by the mount and having a flange portion with an inner surface;
- a rotor magnet which is provided on the inner surface of the flange portion of the rotor yoke;
- a window portion formed in said flange portion such that a part of said rotor magnet faces outwardly;
- and
- an inductor which is disposed in a stator section to oppose a periphery of said flange portion and which detects a magnetic flux of said rotor magnet via said window portion,
- wherein the circuit board does not extend over one side of the mount relative to a rotational center of the rotor yoke and has a total area that is smaller than half a total area of the mount.
A motor apparatus comprising:
- a circuit board which is disposed above a mount;
- a rotor yoke which is rotatably supported by said mount and has a flange portion with an inner surface;
- a rotor magnet which is provided on the inner surface of the flange portion of said rotor yoke;
- stator coils which are disposed between said rotor yoke and said mount and which are arranged radially around a rotational center of said rotor yoke;
- lands which are provided on said circuit board at positions between said stator coils to connect coil terminals of said stator coils;
- and
- an inductor which is mounted on said circuit board to oppose a periphery of said flange portion and which detects a magnetic flux of said rotor magnet via a window portion,
- wherein said circuit board does not extend over one side of the mount relative to said rotational center of said rotor yoke.
An index position detector for a spindle motor, comprising:
- a rotatable rotor magnet having an associated magnetic flux;
- and
- a detector through which the magnetic flux passes and which detects a change over time of the magnetic flux, the change over time of the magnetic flux associated with rotation of said rotatable rotor magnet, said detector being an inductor,
- wherein the inductor is mounted on a circuit board positioned on a mount, the circuit board does not extend over one side of the mount relative to a rotational center of a rotor yoke supported by the mount and on which the rotor magnet is mounted, and the circuit board has a total area that is smaller than half a total area of the mount.
A method to detect an index position of a spindle motor having a rotatable rotor magnet with an associated magnetic flux passing through a detector, said detector being an inductor, the method comprising:
- mounting the detector on a circuit board, the circuit board on a mount, and the rotor magnet on a rotor yoke supported by the mount;
- positioning the circuit board such that the circuit board does not extend over one side of the mount relative to a rotational center of the rotor yoke;
- limiting an area of the circuit board such that the area of the circuit board is smaller than half a total area of the mount;
- rotating the rotatable rotor magnet;
- and
- detecting a change over time of the magnetic flux associated with rotation of the rotatable rotor magnet.
Dependencies are inferred from the claim text.