Method and Apparatus for Detecting an Initial Lubrication of a Moving Component
20230003690 · 2023-01-05
Assignee
Inventors
- William Bishop (Pleasantville, NY, US)
- Gary Mohr (Cortlandt Manor, NY, US)
- Blair Fraser (Cambridge, CA)
Cpc classification
F16N2210/14
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
G01N2291/0258
PHYSICS
G01N29/46
PHYSICS
F16N29/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F16N29/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
G01N29/44
PHYSICS
Abstract
An apparatus and method for detecting an initial lubrication of a moving component including an ultrasonic sensor for detecting an ultrasonic output signal from the moving component and a processor for operating on the output signal. The processor determines if there has been an initiation of a lubrication operation. After identifying the initiation of the lubrication operation, the processor monitors the ultrasonic output signal received from the ultrasonic sensor to detect a momentary increase in the amplitude of the ultrasonic output signal above a level that indicates a need for lubrication, and which is indicative of an initial interaction between a lubricant and the moving component. Upon detecting the momentary increase in the amplitude, the processor tracks a progress of the lubrication operation by detecting for a sustained decrease in the amplitude of the ultrasonic output signal received from the ultrasonic sensor.
Claims
1. An apparatus for detecting an initial lubrication of a moving component, comprising: an ultrasonic sensor that detects an ultrasonic output signal from the moving component; and a processor communicatively coupled to the ultrasonic sensor and comprising a storage, the storage having stored therein instructions that, when executed, cause the processor to: receive, from the ultrasonic sensor, the ultrasonic output signal detected from the moving component; identify an initiation of a lubrication operation; after identifying the initiation of the lubrication operation, monitor the ultrasonic output signal received from the ultrasonic sensor to detect a momentary increase in an amplitude of the ultrasonic output signal above a level that indicates a need for lubrication, and which is indicative of an initial interaction between lubricant and the moving component; and upon detecting the momentary increase in amplitude, track progress of the lubrication operation by detecting a sustained decrease in the amplitude for the ultrasonic output signal received from the ultrasonic sensor.
2. The apparatus of claim 1, wherein the momentary increase in the amplitude is at least a 3 dB (decibel) increase in the ultrasonic output signal within 2 seconds.
3. The apparatus of claim 1, wherein the storage further comprises instructions that, when executed, cause the processor to generate an event alarm when the momentary increase in the amplitude is not detected by the monitoring within a time threshold.
4. The apparatus of claim 3, wherein the time threshold is about 1-2 seconds to about 5 minutes.
5. The apparatus of claim 1, wherein the storage further comprises instructions that, when executed, cause the processor to confirm the initial interaction between the lubricant and the moving component by detecting for an immediate decrease in the amplitude of the ultrasonic output signal after the detected momentary increase in amplitude.
6. The apparatus of claim 5, wherein the immediate decrease in the amplitude is at least a 7 dB (decibel) decrease within 2 seconds from the detected momentary increase in the amplitude, and an event alarm is generated when the immediate decrease in the amplitude is not detected.
7. The apparatus of claim 1, wherein the sustained decrease is at least a 7 dB (decibel) decrease from a level of the ultrasonic output signal before the initiation of the lubrication operation.
8. A method for detecting an initial lubrication of a moving component, comprising: receiving, by a processor from an ultrasonic sensor, an ultrasonic output signal detected from the moving component; identifying, by the processor, an initiation of a lubrication operation; after identifying the initiation of the lubrication operation, monitoring, by the processor, the ultrasonic output signal received from the ultrasonic sensor to detect a momentary increase in an amplitude of the ultrasonic output signal above a level that indicates a need for lubrication, and which is indicative of an initial interaction between a lubricant and the moving component; and upon detecting the momentary increase in amplitude, tracking, by the processor, a progress of the lubrication operation by detecting a sustained decrease in the amplitude of the ultrasonic output signal received from the ultrasonic sensor.
9. The method of claim 8, wherein the momentary increase in the amplitude is at least a 3 dB (decibel) increase in the ultrasonic output signal within 2 seconds.
10. The method of claim 8, further comprising generating an event alarm when the momentary increase in the amplitude is not detected by the monitoring within a time threshold.
11. The method of claim 10, wherein the time threshold is about 1-2 seconds to about 5 minutes.
12. The method of claim 8, further comprising confirming the initial interaction between the lubricant and the moving component by detecting an immediate decrease in the amplitude of the ultrasonic output signal after the detected momentary increase in amplitude.
13. The method of claim 12, wherein the immediate decrease in the amplitude is at least a 7 dB (decibel) decrease within 2 seconds from the detected momentary increase in the amplitude, and an event alarm is generated when the immediate decrease in the amplitude is not detected.
14. The method of claim 8, wherein the sustained decrease is at least a 7 dB (decibel) decrease from a level of the ultrasonic output signal before the initiation of the lubrication operation.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The foregoing and other objects and advantages of the present invention will become more apparent when considered in connection with the following detailed description and appended drawings in which like designations denote like elements in the various views, and wherein:
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
DETAILED DESCRIPTION OF THE INVENTION
[0035] In one embodiment of the present invention there are organizations responsible for maintenance at large factories spread out over acres of land. Such factories frequently contain numerous motors, each having at least one set of bearings.
[0036] As shown in
[0037] In a preferred embodiment, the lubrication dispenser is equipped with an electric motor that drives a piston when active so as to push grease into line 64. The motor can provide a smooth delivery of motion of the piston or it can be a stepper motor that moves the piston in small increments. In such a case, there may be no need for a valve. However, to ensure that grease does not leak into the bearing, the motor can be activated with a valve.
[0038] The ultrasonic signals picked up by sensor 20 are sent to a control circuit 85 over lines 22 in
[0039] Circuit 85 has a power supply driven by the electrical power provided for the motor. However, in situations where the motor power may be intermittent, a backup battery 87 is also enclosed.
[0040] In accordance with an exemplary embodiment of the present invention, lubricant delivery initiations (e.g., a start signal issued by the local controller) are monitored for commencing an initial lubrication detection process that detects for the lubricant reaching and interacting with a moving part (e.g., bearings) after the lubricant has been dispensed.
[0041] As shown in
[0042] Where digital processing is preferred, the output of the analog front end 32 is fed to the input of heterodyne circuitry in the processor where it is sampled at a predetermined sample rate by an analog-to-digital converter. The processor generates a configurable digital carrier signal that is user selectable for the heterodyne circuit's mixer with a frequency range of about 20 kHz to 100 kHz. The samples of the digital version of the ultrasound signal and the carrier are multiplied together in the mixer. The result is digitally filter so as to reject all frequencies except for the audio frequency spectrum with a range between 0 Hz and approximately 5 kHz.
[0043] Use of this digital heterodyning can simplify and improve the heterodyning process by eliminating and replacing traditional analog heterodyning (mixing) circuitry with a digital heterodyning process. The benefits are a decrease in hardware component count, reduced PC Board size, and typically reduce power consumption. Further, there is an increase in the accuracy, stability, and repeatability of the user selectable carrier frequency. Typical analog carrier signal generators incorporate volage controlled oscillators whose frequency output can drift over time and temperature. In addition, carrier frequency calibration is eliminated. Analog circuits typically require factory calibration and periodic recalibration. This is eliminated by using a digital time base clock whose output is easily selectable, repeatable, stable and requires no calibration. There is also an increased accuracy in the dB measurements amplitude. The output signal amplitude of analog mixers used in the heterodyning process can also have variations due to temperature and carrier frequency drift. Because the analog mixing circuits are eliminated, the accuracy of the dB measurement is increased. Full scale dB calibration is also eliminated because there is no need for analog dB reference levels. This can be referred to as “Digital Heterodyning.”
[0044] The processor 36 makes a determination about the amplitude of the audio signal based on the minimum signal the sensor can detect and generates a sensitivity adjustment signal 37 based on an “auto sensitivity adjustment algorithm.” As shown in the flow chart of
[0045] A voltage to current converter 38 receives a DC voltage (DAC Output-1) 42 from processor 36 and produces a sensor system output that is a dB output linearly proportional to the amplitude of the heterodyne audio or ultrasound. In an exemplary embodiment the DAC Output-1 is converted to a linear current output with a range of approximately 0.50 mA to 16.30 mA. This range corresponds to a 0 dB to 100 dB change in amplitude of the ultrasound signal received directly from the analog front end 32 or the heterodyned audio. Wider ranges are available. The output signal can also be configured as a scaled output 0 to 25 mA current signal, or a 4 to 20 mA current loop.
[0046] As noted above, the sensor system has a feature that allows the processor to digitally heterodyne the ultrasound and digitally filter out the digital audio data. DAC Output-2 44 is the analog audio signal that is reconstructed from the digital audio data from the digital heterodyne process. This process is separate from the analog heterodyning process. There may be some nuances that one heterodyne process may pick up that the other may not. Therefore, both analog and digital heterodyning processes can be made available for maximum flexibility.
[0047] In addition to calculating sensitivity, the processor performs fast Fourier transfer (FFT) calculations and/or other digital signal processing algorithms. The processor has a communications output 46 that provides dB and data outputs by means of digital-to-analog converters, communication ports and protocols. The communication output may also provide temperature, and WAV file data for additional external analysis. According to an exemplary implementation of the present invention, processor 36 further incorporates one or more process steps to recognize an initial lubrication of a moving part—for example, a bearing mechanism—by detecting an increase in an elevated amplitude of audio signal 33 and/or ultrasound signal 35, which will be described in further detail below with reference to
[0048] The auto sensitivity operation of processor 36 is shown in
[0049] If at step 56 it is determined that the dB reading is above the upper threshold, the sensitivity signal is reduced by an increment at step 53 and the new value is tested again at step 56 to see if it is still above the upper threshold. Similarly, if in step 58 it is determined that the dB signal is not above the lower threshold, the sensitivity signal is increased by an increment in step 53 and the decisions about being above the upper threshold and below the lower threshold are repeated in steps 56 and 58 until there is no change, indicating that the gain has been adjusted to put the input signal in the operative range. The upper and lower thresholds are adjustable. Typically, the upper threshold is 90% of full scale and the lower threshold is 10% of full threshold. Also, the signal adjustment increments may be adjustable.
[0050] Thus, the auto sensitivity adjustment algorithm determines whether the signal is saturating, i.e., above the upper threshold, which can prevent the making of accurate decibel calculations. In such a case the auto sensitivity algorithm calculates a lower sensitivity setting (gain) to bring the ultrasonic signal to within an acceptable working range The processor also calculates a lower sensitivity threshold, which the signal must be above in order to bring the ultrasonic signal to within an acceptable working range. In such a case the auto sensitivity algorithm calculates a higher sensitivity setting to bring the ultrasonic signal up to within an acceptable working range.
[0051] The processor 36 monitors the digitized amplitude level of both the ultrasound and the audio and automatically adjusts the sensitivity (the gain) of the analog front end preamplifier 32 if the digitized amplitude level is out of range, i.e., “auto sensitivity adjustment is performed.” When the ultrasound and/or the audio are in an acceptable working range the processor calculates the ultrasound amplitude dB value and the audio amplitude dB value.
[0052] As noted above, the sensor system has the ability to heterodyne the ultrasound that is fed into the processor's analog to digital converter directly using digital signal processing techniques. These techniques include generation of a configurable carrier signal, performing digital amplitude modulation with the configurable carrier frequency and the digitizing of the amplitude of the ultrasound, and extracting the digital heterodyned audio spectrum “digital audio” produced by the digital AM modulation using low pass digital filtering algorithms.
[0053] The sensor system provides enhanced signal processing capabilities of the detected ultrasound or heterodyned ultrasound signal, such as spurious glitch detection and/or filtering, fast or slow peak detection, and other advanced pattern recognition capabilities that allow for the detection, processing, and/or reporting of specific events.
[0054] The auto-sensitivity adjustment feature enables users to automatically adjust the sensitivity in a range from 0 dB to 100 dB, and may be 0 dB to 120 dB, as opposed to the 40 dB adjustable window of the prior art.
[0055] As noted before, numerous motors, each having at least one set of bearings, can be spread across large facilities. Each of these motors would require periodic lubrication, which can be undertaken by operators using handheld devices and/or automated systems with direct connections to lubricant supplies, via tubing and the like.
[0056] As illustrated in
[0057] Thus, lubricant (e.g., grease) that is injected via fitting 11 does not immediately reach its intended lubrication target, the bearings in the interior chamber 90. Furthermore, in facilities with motors that are disposed at distant locations, tubing (and/or piping) to respective grease fittings 11 can cover substantial distances. Consequently, any lubricant that is applied from a supply 62 to a particular motor 10 in a facility may require significant travel distance and time before reaching the particular motor 10, let alone the interior chamber 90 for the bearings that require the lubrication.
[0058]
[0059] As illustrated in
[0060] However, if there is not a detected momentary increase in friction, there may be a blockage in the grease path, the grease line may be disconnected, and/or the volume of grease added is not enough to cause an increase in ultrasound (did not cause an increase in friction from the rolling elements distributing the grease throughout the bearings). Accordingly, in an exemplary implementation, a process and an apparatus for detecting this momentary increase in friction are provided to ensure that lubricant has reached an intended moving component target and, if not, to generate an alert for maintenance service for the lubrication mechanism.
[0061]
[0062] At step 80, a dB reading detected from a moving component (e.g., motor 10) is determined and monitored over time (e.g., plot 70 of
[0063] Next at step 82, a determination is made as to whether a lubrication operation has been initiated (“LUBRICATION START?”). According to an exemplary embodiment, processor 36 is communicatively connected to a lubricant controller (not shown) and determines whether the lubricant controller has issued a signal or command for dispensing a lubricant to the moving component (e.g., motor 10). In certain embodiments, a lubricant controller in an automated lubrication mechanism that can make the determination of whether it has issued such a signal or command in response to a sustained elevated dB level detected at step 80 (e.g., at or above second threshold 76 in
[0064] If a lubrication initiation is identified at step 82 (e.g., a lubrication start signal has been issued or detected) (“YES”), the operation proceeds to step 84, where a determination is made on whether a momentary increase (e.g., at or above a threshold rate of increase) has occurred for the monitored dB level. Referring back to
[0065] If the time threshold has not elapsed (“NO”), the operation returns to step 84 to continue detecting for the momentary increase. If, however, the time threshold has elapsed (“YES”), the operation proceeds to step 88 where an event alarm is generated so that the lubrication mechanism can be checked and serviced, if needed. Additionally, increased lubricant volume and/or pressure can be provided in response to such an event alarm. In certain embodiments, plural lubrication start signals can be issued in a series for dispensing the lubricant to the moving component. In such embodiments, the time threshold determination of step 86 can be based on a first lubrication start signal or, alternatively, based on one or more of the plural lubrication start signals (e.g., dispensed lubricant volume threshold based on lubricant volume per start signal).
[0066] Returning to step 84, if the momentary increase is detected, the operation proceeds to step 89 to track the progress and confirm proper lubrication of the moving component. According to one embodiment, the dB level is tracked for a drop (or decrease in amplitude)—e.g., to below first threshold 74 (
[0067] Once proper initial lubrication is confirmed, progress of the lubrication operation is tracked for completion. For example, the dB level is monitored to ensure a sustained lower operating level for the moving component (e.g., below first threshold 74 for more than about 1-2 seconds to about 5 minutes depending upon one or more of a model, a size, or a structural arrangement of the moving component, structural characteristics of the internal lubricant feed channel of the moving component, to name a few, as well understood by one of ordinary skill in the art) and to complete the lubrication operation before any increase in the dB level due to over-lubrication. In an embodiment, the sustained lower operating level is a decrease of at least 7 dB from an operating level of the moving component before the lubrication operation was initiated.
[0068] While the present invention has been particularly shown and described with reference to preferred embodiments thereof; it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, and that the embodiments are merely illustrative of the invention, which is limited only by the appended claims. In particular, the foregoing detailed description illustrates the invention by way of examples and not by way of limitation. The description enables one skilled in the art to make and use the present invention, and describes several embodiments, adaptations, variations, and method of uses of the present invention.