Stepping motor with a coded pole pattern
First Claim
1. A stepping motor comprising:
- a rotor having a predetermined number of rotor poles,said rotor having a rotational axis;
a first stator having a number of stator poles corresponding to said predetermined number of rotor poles;
said stator poles disposed to magnetically interact with said rotor poles to generate a torque on said rotor tending to rotate said rotor around said rotational axis in accordance with an electrical drive applied to said stator poles;
wherein said rotor poles are configured in accordance with a magnetic pattern based on a code;
wherein said code has an autocorrelation function having a single maximum peak magnitude value per code modulo and a plurality of off maximum peak magnitude values;
wherein a greatest peak magnitude value of said plurality of off maximum peak magnitude values is less than one half of the single maximum peak magnitude value.
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Accused Products
Abstract
The present invention relates to a stepping motor with a magnet pole pattern having a predetermined pattern around the circumference of the stepping motor. In one embodiment, the pattern relates to a code having a unique single maximum autocorrelation peak over the period of the code. Example codes include Barker codes, PN codes, Kasami codes, Golomb ruler codes, and other codes. In one embodiment, the rotor and stator have a matching pole pattern. In one embodiment, the drive is arranged to align the poles in an inline configuration, alternatively, the drive may be arranged to align the poles in a diagonal configuration. In a further embodiment, one or more sets of poles are provided on the stator, each set being offset rotationally by a partial pole spacing.
53 Citations
22 Claims
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1. A stepping motor comprising:
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a rotor having a predetermined number of rotor poles, said rotor having a rotational axis; a first stator having a number of stator poles corresponding to said predetermined number of rotor poles; said stator poles disposed to magnetically interact with said rotor poles to generate a torque on said rotor tending to rotate said rotor around said rotational axis in accordance with an electrical drive applied to said stator poles; wherein said rotor poles are configured in accordance with a magnetic pattern based on a code;
wherein said code has an autocorrelation function having a single maximum peak magnitude value per code modulo and a plurality of off maximum peak magnitude values;wherein a greatest peak magnitude value of said plurality of off maximum peak magnitude values is less than one half of the single maximum peak magnitude value. - View Dependent Claims (5, 6, 7, 8, 9, 10)
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2. A stepping motor comprising:
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a rotor having a predetermined number of rotor poles, said rotor having a rotational axis; a first stator having a number of stator poles corresponding to said predetermined number of rotor poles; said stator poles disposed to magnetically interact with said rotor poles to generate a torque on said rotor tending to rotate said rotor around said rotational axis in accordance with an electrical drive applied to said stator poles; wherein said rotor poles are configured in accordance with a magnetic pattern based on a code;
wherein said code has an autocorrelation function having a single maximum peak per code modulo and a plurality of off maximum peak values wherein said off maximum peak values are less than one half of the maximum peak;wherein the code is a Barker code.
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3. A stepping motor comprising:
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a rotor having a predetermined number of rotor poles, said rotor having a rotational axis; a first stator having a number of stator poles corresponding to said predetermined number of rotor poles; said stator poles disposed to magnetically interact with said rotor poles to generate a torque on said rotor tending to rotate said rotor around said rotational axis in accordance with an electrical drive applied to said stator poles; wherein said rotor poles are configured in accordance with a magnetic pattern based on a code;
wherein said code has an autocorrelation function having a single maximum peak per code modulo and a plurality of off maximum peak values wherein said off maximum peak values are less than one half of the maximum peak;wherein the code is a PN sequence code.
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4. A stepping motor comprising:
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a rotor having a predetermined number of rotor poles, said rotor having a rotational axis; a first stator having a number of stator poles corresponding to said predetermined number of rotor poles; said stator poles disposed to magnetically interact with said rotor poles to generate a torque on said rotor tending to rotate said rotor around said rotational axis in accordance with an electrical drive applied to said stator poles; wherein said rotor poles are configured in accordance with a magnetic pattern based on a code;
wherein said code has an autocorrelation function having a single maximum peak per code modulo and a plurality of off maximum peak values wherein said off maximum peak values are less than one half of the maximum peak;wherein the code is a Golomb ruler code.
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11. A method for operating a stepping motor, said stepping motor having a predetermined number of poles in a first stator and corresponding number of poles in a rotor magnetically coupled to said first stator, said method comprising the steps of:
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producing a magnetic field pattern in said rotor in accordance with a code; producing a magnetic field pattern in said first stator in accordance with said code; and sequentially shifting said magnetic field pattern in at least one of said rotor or said first stator to effect rotation of said rotor; wherein said rotor poles are configured in accordance with a magnetic pattern based on a code;
wherein said code has an autocorrelation function having a single maximum peak magnitude value per code modulo and a plurality of off maximum peak magnitude values;wherein a greatest peak magnitude value of said plurality of off maximum peak magnitude values is less than one half of the single maximum peak magnitude value. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
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12. A method for operating a stepping motor, said stepping motor having a predetermined number of poles in a first stator and corresponding number of poles in a rotor magnetically coupled to said first stator, said method comprising the steps of:
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producing a magnetic field pattern in said rotor in accordance with a code; producing a magnetic field pattern in said first stator in accordance with said code; and sequentially shifting said magnetic field pattern in at least one of said rotor or said first stator to effect rotation of said rotor; wherein said code has an autocorrelation function having a single maximum peak per code modulo and a plurality of off maximum peak values wherein the off maximum peak values are less than one half of the maximum peak; wherein the code is a Barker code.
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13. A method for operating a stepping motor, said stepping motor having a predetermined number of poles in a first stator and corresponding number of poles in a rotor magnetically coupled to said first stator, said method comprising the steps of:
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producing a magnetic field pattern in said rotor in accordance with a code; producing a magnetic field pattern in said first stator in accordance with said code; and sequentially shifting said magnetic field pattern in at least one of said rotor or said first stator to effect rotation of said rotor; wherein said code has an autocorrelation function having a single maximum peak per code modulo and a plurality of off maximum peak values wherein the off maximum peak values are less than one half of the maximum peak; wherein the code is a PN sequence code.
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14. A method for operating a stepping motor, said stepping motor having a predetermined number of poles in a first stator and corresponding number of poles in a rotor magnetically coupled to said first stator, said method comprising the steps of:
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producing a magnetic field pattern in said rotor in accordance with a code; producing a magnetic field pattern in said first stator in accordance with said code; and sequentially shifting said magnetic field pattern in at least one of said rotor or said first stator to effect rotation of said rotor; wherein said code has an autocorrelation function having a single maximum peak per code modulo and a plurality of off maximum peak values wherein the off maximum peak values are less than one half of the maximum peak; wherein the code is a Golomb ruler code.
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Specification