The Experts below are selected from a list of 33 Experts worldwide ranked by ideXlab platform
Torao Egashira - One of the best experts on this subject based on the ideXlab platform.
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Unraveling the Image of Commutation Spark Generated in Universal Motors
IEEJ Transactions on Industry Applications, 2003Co-Authors: Tamio Hanazawa, Ali Almazroui, Torao EgashiraAbstract:A universal motor, which is mainly used in vacuum cleaners, generates commutation sparks at the moment when the brush and the Commutator Segment are separated from each other during rotation. This study investigates the mechanism of commutation spark generation by analyzing high-speed camera images and its electrical aspect. We invented a new external trigger method that used laser light as the trigger signal for the shuttering a high-speed camera. This method enabled us to photograph sparks on any desired Commutator Segments during high-speed rotation, and that made the analysis after photographing easier. This paper shows that commutation sparks in universal motors are generated on every other Commutator Segment and at the peak of pulses in the voltage between the brush and Commutator Segment. Other aspects are also clarified, such as the generation of the singular and plural number of sparks on one Commutator Segment at a time, the time from the moment of spark generation to extinction, and spark generation during a single rotation.
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The Commutation Spark on a Commutator Segment of Universal Motors
IEEJ Transactions on Industry Applications, 2001Co-Authors: Tamio Hanazawa, Torao EgashiraAbstract:We have been trying to probe the commutation spark mechanism of high-revolving universal motors with two visions of a high-speed camera and brush sparking voltage. The generation of commutation sparks coincides with large pulses in brush sparking voltage, and the sparks occur when the large pulses begin to decrease at the peak. The shape of a single peak value in large pulses becomes a triangle, and plural peak values form square-wave. This paper shows that it is possible to judge generation of commutation sparks easily by observing shapes of peak values of large pulses in armature terminal voltage with a synchroscope.
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photographing of commutation spark by external laser triggering
The Review of Laser Engineering, 1998Co-Authors: Tamio Hanazawa, Torao EgashiraAbstract:The single-phase AC Commutator motor (universal motor) is a compact, lightweight and high-revolution motor that is widely used in such domestic electric appliances as cleaners, juicers, electric drills. Some problems generated by commutation sparks are wear on the brush and noise impediments. We have therefore attempted to use a high-speed camera to elucidate the commutation spark mechanism visually. We proposed an external trigger method that an argon laser is used for the external trigger signal of high-speed camera. This method enabled us to photograph the motor's Commutator Segment from any position.
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Photography of the commutation spark using a high-speed camera
Ultrahigh- and High-Speed Photography and Image-based Motion Measurement, 1997Co-Authors: Tamio Hanazawa, Torao Egashira, Yasuhiro Tanaka, Jun EgoshiAbstract:In the single-phase AC Commutator motor (known as a universal motor), which is widely used in cleaners, electrical machines, etc., some problems generated by commutation sparks are wear on the brush and noise impediments. We have therefore attempted to use a high-speed camera to elucidate the commutation spark mechanism visually. The high-speed camera that we used is capable of photographing at 5,000 - 20,000,000 frames/s. Selection of a trigger module can be obtained from the operation unit and the exterior triggering signal. In this paper, we proposed an exterior trigger method that involved opening a hole of several millimeters across in the motor and using argon laser light, so that Commutator Segments may be photographed in position; we then conducted the experiment. This method enabled us to photograph the motor's Commutator Segment from any position, and we were able to confirm spark generation at every other Commutator Segment. Furthermore, after confirming the spark generation position of the Commutator Segment, we next attempted to accelerate the photographing speed to obtain more detailed photography of the moment of spark generation; we then prepared our report.
Tamio Hanazawa - One of the best experts on this subject based on the ideXlab platform.
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Unraveling the Image of Commutation Spark Generated in Universal Motors
IEEJ Transactions on Industry Applications, 2003Co-Authors: Tamio Hanazawa, Ali Almazroui, Torao EgashiraAbstract:A universal motor, which is mainly used in vacuum cleaners, generates commutation sparks at the moment when the brush and the Commutator Segment are separated from each other during rotation. This study investigates the mechanism of commutation spark generation by analyzing high-speed camera images and its electrical aspect. We invented a new external trigger method that used laser light as the trigger signal for the shuttering a high-speed camera. This method enabled us to photograph sparks on any desired Commutator Segments during high-speed rotation, and that made the analysis after photographing easier. This paper shows that commutation sparks in universal motors are generated on every other Commutator Segment and at the peak of pulses in the voltage between the brush and Commutator Segment. Other aspects are also clarified, such as the generation of the singular and plural number of sparks on one Commutator Segment at a time, the time from the moment of spark generation to extinction, and spark generation during a single rotation.
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The Commutation Spark on a Commutator Segment of Universal Motors
IEEJ Transactions on Industry Applications, 2001Co-Authors: Tamio Hanazawa, Torao EgashiraAbstract:We have been trying to probe the commutation spark mechanism of high-revolving universal motors with two visions of a high-speed camera and brush sparking voltage. The generation of commutation sparks coincides with large pulses in brush sparking voltage, and the sparks occur when the large pulses begin to decrease at the peak. The shape of a single peak value in large pulses becomes a triangle, and plural peak values form square-wave. This paper shows that it is possible to judge generation of commutation sparks easily by observing shapes of peak values of large pulses in armature terminal voltage with a synchroscope.
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photographing of commutation spark by external laser triggering
The Review of Laser Engineering, 1998Co-Authors: Tamio Hanazawa, Torao EgashiraAbstract:The single-phase AC Commutator motor (universal motor) is a compact, lightweight and high-revolution motor that is widely used in such domestic electric appliances as cleaners, juicers, electric drills. Some problems generated by commutation sparks are wear on the brush and noise impediments. We have therefore attempted to use a high-speed camera to elucidate the commutation spark mechanism visually. We proposed an external trigger method that an argon laser is used for the external trigger signal of high-speed camera. This method enabled us to photograph the motor's Commutator Segment from any position.
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Photography of the commutation spark using a high-speed camera
Ultrahigh- and High-Speed Photography and Image-based Motion Measurement, 1997Co-Authors: Tamio Hanazawa, Torao Egashira, Yasuhiro Tanaka, Jun EgoshiAbstract:In the single-phase AC Commutator motor (known as a universal motor), which is widely used in cleaners, electrical machines, etc., some problems generated by commutation sparks are wear on the brush and noise impediments. We have therefore attempted to use a high-speed camera to elucidate the commutation spark mechanism visually. The high-speed camera that we used is capable of photographing at 5,000 - 20,000,000 frames/s. Selection of a trigger module can be obtained from the operation unit and the exterior triggering signal. In this paper, we proposed an exterior trigger method that involved opening a hole of several millimeters across in the motor and using argon laser light, so that Commutator Segments may be photographed in position; we then conducted the experiment. This method enabled us to photograph the motor's Commutator Segment from any position, and we were able to confirm spark generation at every other Commutator Segment. Furthermore, after confirming the spark generation position of the Commutator Segment, we next attempted to accelerate the photographing speed to obtain more detailed photography of the moment of spark generation; we then prepared our report.
Thulasirajan Ganesan - One of the best experts on this subject based on the ideXlab platform.
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Failure assessment using accelerated testing on IC engine’s starter motor for reliability improvement
Life Cycle Reliability and Safety Engineering, 2019Co-Authors: Sumanchandran Devendran, Rajeshkumar Ramasamy, Varatharaj Neelakandan, Thulasirajan GanesanAbstract:Generally, starter motors are tested at increased usage rate to verify the durability of the component and to identify the premature failure aspects in the controlled ambient environment. During the process, the latent failures which exhibit unique failure modes at variable environment are hidden, which can impact the warranty of the product. Specifically the Stop–Start (SS)-type starter motors, which often work under increased thermal condition, may show latent failures. Principally, a starter motor is mounted over the IC engine where the working temperature is always between 60 and 120 °C, to establish easy contact with the engine flywheel during cranking. Hence, identifying the latent failures of the starter motor at increased thermal condition is useful to ensure the reliability of the motor as per the requirements of automotive manufacturers. This paper emphasis to improve the reliability of the starter motor’s Commutator for high-temperature applications, which may exhibit the failure mode of “Commutator Segment Lift”. The said analysis is performed using time-to-failure data from the laboratory testing of proto samples. This reliability study for the design improvement on Commutator includes failure mechanism study, failure source identification and failure improvement.
Takashi Fukutsuka - One of the best experts on this subject based on the ideXlab platform.
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Fundamental investigation on DC arc formation and extinction in separation process of brush and Commutator Segment
2017 4th International Conference on Electric Power Equipment - Switching Technology (ICEPE-ST), 2017Co-Authors: K. Oshima, Yasunobu Yokomizu, Takashi FukutsukaAbstract:Fundamental experiments were made for a DC arc in a separation process of a brush and a Commutator Segment. Firstly, we constructed an equipment composed of a fixed graphite-electrode (simulating a brush) and a movable copper-electrode (simulating a Commutator Segment). This equipment employed a sliding-movement separation process of the electrodes. From a waveform measured under a DC source of 12.6 V, a breaking voltage of about 4 V proved to be generated immediately before the electrodes separation. It was also found that an almost constant voltage of 14 V maintained to be generated between the electrodes during an arc formation. This voltage was considered to be an electrode fall voltage. The breaking voltage and the electrode fall voltage therefore proved to be important factors for affecting the current decreasing process. Secondly, these voltages were compared with those measured for an axial-movement separation.
Jun Egoshi - One of the best experts on this subject based on the ideXlab platform.
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Photography of the commutation spark using a high-speed camera
Ultrahigh- and High-Speed Photography and Image-based Motion Measurement, 1997Co-Authors: Tamio Hanazawa, Torao Egashira, Yasuhiro Tanaka, Jun EgoshiAbstract:In the single-phase AC Commutator motor (known as a universal motor), which is widely used in cleaners, electrical machines, etc., some problems generated by commutation sparks are wear on the brush and noise impediments. We have therefore attempted to use a high-speed camera to elucidate the commutation spark mechanism visually. The high-speed camera that we used is capable of photographing at 5,000 - 20,000,000 frames/s. Selection of a trigger module can be obtained from the operation unit and the exterior triggering signal. In this paper, we proposed an exterior trigger method that involved opening a hole of several millimeters across in the motor and using argon laser light, so that Commutator Segments may be photographed in position; we then conducted the experiment. This method enabled us to photograph the motor's Commutator Segment from any position, and we were able to confirm spark generation at every other Commutator Segment. Furthermore, after confirming the spark generation position of the Commutator Segment, we next attempted to accelerate the photographing speed to obtain more detailed photography of the moment of spark generation; we then prepared our report.