EP0079451A1
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EP
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A method of testing stepping motors
Assignee: International Business Machines Corp
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Filing: 1982-09-28
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Granted: —
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Expires: 2002-09-28
Abstract
Abstract The phases (ΦA-ΦC) of the moteur (10) are connected in series, and a constant current is applied to the phases. The rotor (12) of the motor (10) under test is rotated at a constant speed, and the voltage drop across each phase is measured and converted into back EMF. The back EMF is then analyzed to determine a characteristic of the motor (10), for example stepping accuracy of each of the phases, or related torque information, and the result of the analysis is then compared with a predetermined motor parameter to provide comparison data or a signal of a pass or fail condition based upon the comparison.
Inventors
- 👤 Jerry Wesley Raider
- 👤 Earl Dawson Ward Ii
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 16:35
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/34
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
123 words
A method of testing" a stepping motor (10) having a stator (11) with a plurality of phases (θ A -θ C ) and a rotor (12), characterized in that it comprises the steps of: connecting the phases (0 -0 ) of the motor (10) in series; applying a constant current to said phases (θ A -θ C ); rotating said rotor (12) at a constant speed; measuring a voltage drop across at least one phase and converting said voltage drop into back EMF for said at least one phase; analyzing the back EMF of at least said one phase to determine a parameter of said motor (10). comparing said parameter with a known comparable parameter to determine the acceptability of said motor (10).
Claim 2
Independent Claim
123 words
A method of testing" a stepping motor (10) having a stator (11) with a plurality of phases (θ A -θ C ) and a rotor (12), characterized in that it comprises the steps of: connecting the phases (0 -0 ) of the motor (10) in series; applying a constant current to said phases (θ A -θ C ); rotating said rotor (12) at a constant speed; measuring a voltage drop across at least one phase and converting said voltage drop into back EMF for said at least one phase; analyzing the back EMF of at least said one phase to determine a parameter of said motor (10). comparing said parameter with a known comparable parameter to determine the acceptability of said motor (10).
Claim 3
Dependent Claim
39 words
A method in accordance with Claim 1 including the steps of measuring the voltage drop across each phase and converting the measured voltage of each phase into back EMF for each of said phases (θ A -θ C ).
Claim 4
Dependent Claim
37 words
A method in accordance with Claim 2 including the steps of analyzing the back EMF of said phase to determine the stepping accuracy of said phase, and comparing the determined stepping accuracy with a predetermined stepping accuracy.
Claim 5
Dependent Claim
53 words
A method in accordance with Claim 2 including the steps of analyzing the back EMF of each said phases (θ A -θ C ) by applying several constant current levels to determine the running torque of said motor (10), and comparing the determined running torque of said motor with a predetermined running torque."
Claim 6
Dependent Claim
61 words
A method in accordance with Claim 2 including the steps of measuring the time for a predetermined current rise after application of current to said series connected phases (θ A -θ C ), and analyzing said current rise to determine the average'inductance of said phases (θ A -θ C ), and comparing the determined average inductance with a predetermined average inductance.
Claim 7
Dependent Claim
44 words
A method in accordance with Claim 2 including the steps of analyzing the back EMF of each of said phases (θ A -θ C ) to determine the hysteresis losses of said motor (10), and comparing the hysteresis losses with a predetermined hysteresis loss.
Claim 8
Dependent Claim
48 words
A method in accordance with Claim 2 including the steps of analyzing the back EMF of each of said phases (θ A -θ C ) to determine the phase-to-phase variation in torque between said phases, and comparing the phase-to-phase variation in said torque with a predetermined phase-to-phase variation.
Claim 9
Dependent Claim
53 words
A method in accordance with Claim 2 including the steps of analyzing the back EMF of each of said phases (θ A -θ C ) to determine the back EMF variation per revolution of said motor (10), and comparing the back EMF variation per revolution with a predetermined back EMF variation per revolution.
Claim 10
Dependent Claim
50 words
9 . A method in accordance with Claim 2 including the steps of analyzing the back EMF of each of said phases (θ A -θ C ) to determine the damping potential of said motor (10), and comparing the damping potential of said motor (10) with a predetermined damping potential.
Claim 11
Dependent Claim
59 words
1 0. A method in accordance with Claim 2 including the steps of analyzing the back EMF of each of said phases (θ A -θ C ) to determine the gap width between the rotor (12) of said motor (10) and the stator (11) of said motor (12), and comparing the determined gap width with a predetermined gap width.
Claim 12
Dependent Claim
54 words
A method in accordance with Claim 2 including the steps of analyzing the total voltage across all of said phases (θ A -θ C ) to determine average resistance and the absence of shorts in each of said phases (θ A -θ C ), and comparing the value found thereby with a predetermined value.
Claim 13
Dependent Claim
36 words
A method in accordance with Claim 11 including the step of analyzing said value found to determine the harmonic content of each of said phases, and comparing the determined harmonic content with a predetermined harmonic content.
References Cited (Backward Citations)
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