Rotation detection device and rotation detector equipped bearing assembly
AssigneeNtn Corporation
InventorsToru Takahashi, Shintarou Ueno
Life of this patent
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Abstract
A rotation detection device includes a plurality of magnetic encoders of a ring shape arranged coaxially and having different numbers of magnetic poles, a plurality of magnetic sensors each operable to detect the magnetic field of the corresponding magnetic encoder and having a function of detecting positional information within a single magnetic pole of the corresponding magnetic encoder, a phase difference detector to determine the phase difference of magnetic field signals detected respectively by the magnetic sensors, and an angle calculator to calculate an absolute rotation angle of the magnetic encoders based on the detected phase difference.
Claims12
A rotation detecting device comprising:
- a plurality of magnetic encoders of a ring shape arranged coaxially and having different numbers of magnetic poles;
- a plurality of magnetic sensors each operable to detect the magnetic field of the corresponding magnetic encoder and having a function of detecting positional information within a single magnetic pole of the corresponding magnetic encoder;
- a phase difference detector to determine the phase difference of magnetic field signals detected respectively by the magnetic sensors;
- and
- an angle calculator to calculate an absolute rotation angle of the magnetic encoders based on the detected phase difference,
- wherein each of the magnetic sensors includes a plurality of sensor elements arranged in offset relation relative to each other within a pitch between the neighboring magnetic poles so as to provide two phase signal outputs forming sine and cosine curves, respectively, and operable to detect the position within the single magnetic pole by frequency multiplication.
A rotation detecting device comprising:
- a plurality of magnetic encoders of a ring shape arranged coaxially and having different numbers of magnetic poles;
- a plurality of magnetic sensors each operable to detect the magnetic field of the corresponding magnetic encoder and having a function of detecting positional information within a single magnetic pole of the corresponding magnetic encoder;
- a phase difference detector to determine the phase difference of magnetic field signals detected respectively by the magnetic sensors;
- and
- an angle calculator to calculate an absolute rotation angle of the magnetic encoders based on the detected phase difference,
- wherein each of the magnetic sensors comprises a line sensor, in which sensor elements are lined up in a direction conforming to the direction in which the magnetic poles of the corresponding magnetic encoder are arranged and is operable to detect the position within the single magnetic pole by generating two phase signal outputs forming sine and cosine curves by unit of calculation.
A rotation detecting device comprising:
- a plurality of magnetic encoders of a ring shape arranged coaxially and having different numbers of magnetic poles;
- a plurality of magnetic sensors each operable to detect the magnetic field of the corresponding magnetic encoder and having a function of detecting positional information within a single magnetic pole of the corresponding magnetic encoder;
- a phase difference detector to determine the phase difference of magnetic field signals detected respectively by the magnetic sensors;
- an angle calculator to calculate an absolute rotation angle of the magnetic encoders based on the detected phase difference;
- and
- an angle information output circuit to output the absolute angle, calculated by the angle calculator, in the form of an ABZ phase signal comprised of two, A phase and B phase pulse signals which are displaced 90° in phase relative to each other and a Z phase pulse signal indicative of a position of origin.
Dependencies are inferred from the claim text.