Machine vibration monitor and method
First Claim
1. A monitor to measure the vibrating frequency of a machine caused by the unbalance of its internal rotors vibrating at several frequencies to determine in advance an approach of excessive vibration and an incipient failure of the machine comprising:
- an accelerometer transducer connected to said machine to receive the total vibration thereof at all operating speeds and produce a single output signal;
an amplifier and uniform level filter connected to said transducer to receive said output signal and raise it to a predetermined substantially constant level over the entire speed range of said machine, said filter having components selected to simultaneously compensate for both the frequency dependence of said signal and the variable displacement allowables of said rotors; and
an oscilloscope adapted to be connected to said filter to receive and display said constant level signal whereby it may be compared with a pre-established reference level of safe operation of said machine.
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Accused Products
Abstract
An accelerometer senses a machine'"'"'s vibration resulting from unbalance of its internal rotors and outputs an electrical signal which is then conditioned by means of an amplifier and uniform level filter. The resulting output signal has individual vibration (frequency) components which are adjusted to match the machine'"'"'s specified vibration limit extending over each of the rotors'"'"' frequency range to achieve a uniform level. A storage oscilloscope is employed to display the conditioned signal.
By utilizing the uniform level filter a normal operating band for the machine can be specified in terms of oscilloscope divisions regardless of the machine'"'"'s operating frequencies. When a signal exceeds the specified band on the oscilloscope the rotor causing the excessive vibration may then be determined by analyzing the individual components. Utilizing relatively uncomplicated electronics, a limit exceedance warning may also be incorporated.
36 Citations
10 Claims
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1. A monitor to measure the vibrating frequency of a machine caused by the unbalance of its internal rotors vibrating at several frequencies to determine in advance an approach of excessive vibration and an incipient failure of the machine comprising:
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an accelerometer transducer connected to said machine to receive the total vibration thereof at all operating speeds and produce a single output signal; an amplifier and uniform level filter connected to said transducer to receive said output signal and raise it to a predetermined substantially constant level over the entire speed range of said machine, said filter having components selected to simultaneously compensate for both the frequency dependence of said signal and the variable displacement allowables of said rotors; and an oscilloscope adapted to be connected to said filter to receive and display said constant level signal whereby it may be compared with a pre-established reference level of safe operation of said machine. - View Dependent Claims (2, 3, 4, 5, 6)
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7. The method of detecting imbalance in the rotor system of a machine while operating, consisting essentially of:
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generating an electrical output signal related to the vibration acceleration developed in the machine; converting said electrical output to an electrical signal whose fundamental frequency components are proportional to each of the machine'"'"'s vibration acceleration components; first conditioning said electrical signal to cause each frequency component to have approximately the same magnitude; then conditioning said electrical signal to cause the sum of said frequency components to remain substantialy constant over the speed range of the machine; and comparing said electrical signal thus conditioned to a predetermined reference level. - View Dependent Claims (8, 9, 10)
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Specification