Test probe for electrical devices having low or no wedge depression
First Claim
1. A probe for detecting abnormalities in an electrical device having an effective wedge depression of no more than 200 mils, comprising:
- a probe core having first and second sensing end portions;
and a sense coil wound about the probe core;
wherein said probe is adapted to detect abnormalities in the electrical device in a spaced, contact-free relationship between and at least partially above opposed adjacent surfaces of portions of the electrical device, forming first and second air gaps between the first and second sensing end portions of the core and the respective opposed adjacent surfaces.
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Accused Products
Abstract
A probe for use in detecting abnormalities in an electrical device having a wedge depression of no more than 100 mils. The probe includes a solid core surrounded by a sense coil. The ends of the core are arranged in a contact-free, spaced relationship between and at least partially above opposed surfaces of adjacent lamination teeth of a stator. Air gaps are maintained between the ends of the probe core and the opposed surfaces. The total of the two air gaps is constant. The probe is supported on a carriage arrangement and moved along the teeth. Variations in leakage flux produced with the stator energized with an energization winding to produce a flux which is a few percent of a normal energization level, are monitored.
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Citations
25 Claims
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1. A probe for detecting abnormalities in an electrical device having an effective wedge depression of no more than 200 mils, comprising:
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a probe core having first and second sensing end portions;
and a sense coil wound about the probe core;
wherein said probe is adapted to detect abnormalities in the electrical device in a spaced, contact-free relationship between and at least partially above opposed adjacent surfaces of portions of the electrical device, forming first and second air gaps between the first and second sensing end portions of the core and the respective opposed adjacent surfaces. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A sensing apparatus for detecting abnormalities in an electrical device having an effective wedge depression of no more than 200 mils, comprising:
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a probe having a core with sensing end portions and a coil wound about the core;
means for supporting said probe being adapted to maintain the sensing end portions of the core in a contact-free, spaced relationship between and at least partially above opposed surfaces of members which form part of the electrical device and through which leakage flux passes; and
means for moving the probe to a new location with respect to the opposed surfaces and detecting leakage flux at the new location. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A sensing apparatus for detecting abnormalities in an electrical device having an effective wedge depression of no more than 200 mils, comprising:
a probe having a structure through which leakage flux passes, comprising;
a probe core having first and second sensing end portions; and
a sense coil wound about the probe core; and
a probe carriage, comprising;
a probe extension piece attached to the probe; and
at least one probe location adjustment screw for adjusting the location of the probe to a spaced, contact-free relationship between and at least partially above opposed adjacent surfaces of portions of the electrical device to form first and second air gaps between the first and second sensing end portions of the core and the respective opposed adjacent surfaces. - View Dependent Claims (16, 17, 18)
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19. A system for detecting abnormalities in an electrical device having an effective wedge depression of no more than 200 mils, comprising:
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a probe including a core formed of a material having high initial permeability and high resistivity characteristics and a coil wound about the core;
a probe carriage adapted to support the probe so that sensing portions of the core are maintained in a contact-free, spaced relationship between and at least partially above predetermined opposed surfaces of the electrical device and so that the sensing portions of the core are exposed to leakage flux produced by the electrical device which passes between the opposed surfaces and through air gaps defined between the opposed surfaces and the sensing portions of the core;
an excitation winding removably disposed with the electrical device and operatively connected with a source of excitation voltage for inducing a flux in an electrical circuit in the electrical device; and
a data acquisition system operatively connected with the excitation winding and the sensor coil for monitoring the output of the sensor and detecting faults in the electrical device which cause change in the leakage flux. - View Dependent Claims (20, 21)
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22. A method for detecting faults in an electrical device having an effective wedge depression depth of no more than 200 mils, comprising the steps of:
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supporting a probe, having a solid core and a coil wound about the core, in a contact-free, spaced relationship between and at least partially above adjacent surfaces of members which form part of the device and through which leakage flux passes;
inducing energization of the electrical device to a predetermined level which is lower than a normal operating level for producing leakage flux;
detecting a leakage flux which occurs between the opposed surfaces using the probe;
moving the probe to a new position with respect to the opposed surfaces and detecting a leakage flux at the new position; and
monitoring the fluctuation in probe output and detecting a fault in response to the detection of an abnormal leakage flux. - View Dependent Claims (23, 24, 25)
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Specification