Abstract A capacitance displacement type measuring probe for measuring the vibration of a dynamoelectric machine including a dynamoelectric machine with helical grooves in its collector ring is disclosed. The probe measures the vibration of the dynamoelectric machine by measuring the change in capacitance of a capacitor established by the probe and the collector ring. The probe has a parallelogram sensing face which includes a sensing electrode having a parallelogrammed sensing surface whose axial length is of a predetermined dimension to coact with the parameters of the collector ring. The axial length of the sensing surface is formed such that the sensing surface scans a constant total high and total low area on the collector as the collector rotates. To measure vibration the probe is deployed at a fixed point in space with its parallelogrammed sensing face in parallel with the longitudinal axis of the rotating member to form a capacitor. The capacitor thus formed is placed in series with a resistor and series circuit is driven by an alternating current signal generator. Change in capacitance results in change of voltage across the capacitor to develop a signal related to vibration of the collector.
A capacitance displacement probe for measuring the vibrations of a rotating member, wherein the probe forms one element of a capacitor and wherein the rotating member forms a second element of the capacitor and is provided with a plurality of equally spaced apart grooves having a predetermined pitch and higher surface elements intermediate the grooves, said probe comprising: a shield electrode, including a window, a pair of guard electrodes and a sensing electrode having a sensing surface, said sensing surface having a length equal to an integer multiple of equal grooves and higher surface elements of the rotating member with which said probe is to be used, first means for securing said guard electrodes within said shield electrode and each having a surface thereof substantially co-extensive with the outer plane of said window, second means for mounting said sensing electrode between and electrically insulated from said guard electrodes, with the sensing surface of said sensing electrode being substantially co-extensive with the outer plane of said window, and means for electrically connecting said sensing electrode surface to an electrical circuit.
Claim 2
Dependent Claim
179 words
A capacitance displacement probe for measuring the vibrations of a rotating member, wherein the probe forms one element of a capacitor and wherein the rotating member forms a second element of the capacitor and is provided with a plurality of equally spaced apart grooves having a predetermined pitch and higher surface elements intermediate the grooves, said probe comprising: a shield electrode, including a window, a pair of guard electrodes and a sensing electrode having a sensing surface, said sensing surface having a length equal to an integer multiple of equal grooves and higher surface elements of the rotating member with which said probe is to be used, first means for securing said guard electrodes within said shield electrode and each having a surface thereof substantially co-extensive with the outer plane of said window, second means for mounting said sensing electrode between and electrically insulated from said guard electrodes, with the sensing surface of said sensing electrode being substantially co-extensive with the outer plane of said window, and means for electrically connecting said sensing electrode surface to an electrical circuit.
Claim 3
Dependent Claim
22 words
A capacitive displacement probe as defined in claim 1, and wherein a dielectric material overlays said window, guard electrodes and sensing surface.