JPH1078386A - Electric resistance monitoring type particle detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discriminate the mass of general abrasive dust from a large broken piece by providing a particle detector for monitoring the resistance between mutually spaced first magnet and second magnet to inspect the tendency of voltage drop. SOLUTION: A particle detector 14 is screwed to a part. The end part including first and second magnets 26, 28 is arranged within the liquid of a part to collect metal particles. The particles fill the space between the first and second magnets 26, 28 to cause a voltage drop, which is then detected by a module 46. The signal from the module 46 is transmitted to a data system 18, and stored and kept therein for a time length for inspecting the tendency of the data. The information of the tendency is used to determine the state of the part and the time for purifying the particle detector 14. The sizes of the particles can be roughly estimated from this data. In general abrasive dust, the voltage drop is increased with the lapse of time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting metal particles created due to normal wear or component failure. More particularly, the present invention relates to a system that can distinguish between normal wear conditions and critical component failure.

[0002]

2. Description of the Related Art In machine systems such as engines, hydraulic systems and transmissions, lubricants such as oil are used to dissipate heat in the system and reduce wear of system components. However, due to the nature of the system, abrasion will occur, creating fine or large metal particles.

[0003]

Particles can be generated by normal wear or by more serious problems. Under normal maintenance procedures, metal particles will be present in the lubricant for an extended period of time. If no metal particles are identified and if no distinction is made between normal wear and component failure, this can lead to undesirable shutdowns and costly repairs. The present invention addresses one or more of the problems described above.

[0004]

SUMMARY OF THE INVENTION In one aspect of the present invention, an apparatus is provided for detecting metal particles in a component. The apparatus includes a particle detector located in a component for collecting particles in a fluid. The particle detector includes a first magnet and two magnets spaced from each other. The apparatus includes means adapted to monitor resistance between the first and second magnets to look for trends in voltage drop and to distinguish between normal wear debris accumulation and large debris.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
In the fluid of the transmission or part 12,
Metal particles due to wear or failure of parts are detected. However, use of the present invention with respect to transmissions is for description purposes only and is not so limited. The present invention is intended for use in engine oil pans, final drives, differentials, torque converters, hydraulic systems and other similar equipment systems. Apparatus 10 includes a particle detector 14 and means 15 for monitoring the resistance, or voltage change, due to metal particles on the particle detector 14. The monitoring means 15 comprises an electrical circuit 16 and a data acquisition and logic system 18 connected to the electrical circuit 16.
And

The particle detector 14 includes a transmission 1
2 is screwed to the first end 22 and protrudes into the transmission 12;
Second end 24 located in the second fluid (not shown)
And a housing 20 having The second end portion 24 includes a first annular magnet 26, a second magnet 28, a magnet 26, and a magnet 26, which are separated from the first magnet 26.
And spacers 30 between the eight. The first connector 32
It is connected to the first magnet 26. The second connector 34 is connected to the second magnet 28. A resistor 36 is connected between the first and second connectors 32,34. In the present invention, a 30 kOhm resistor is shown, but this value can be changed without departing from the scope of the present invention.

The electrical circuit 16 includes a power supply 38 having a first lead 40 connected to a first connector 32 and a second lead 42 connected to a second connector 34. Although power supply 38 in the present invention is shown as an 8 volt power supply, it can be modified to adjust the sensitivity of device 10. Second lead 42 includes a resistor 44.
In the present invention, resistor 44 has a value of 18 kOhm, but this value can be changed to adjust the sensitivity of device 10. A module 46 is connected to the first and second connectors 32, 34 and monitors the voltage output of the device 10. If no metal particles fill the gap between the first and second magnets 26, 28, the module 46
Measures an output voltage of 5 volts (highest). When the voltage of the power supply 38 or the voltage of the resistor 44 is changed,
The maximum output voltage has changed and is no longer 5 volts.

Data Acquisition and Logic System 18
Measures the output from module 46 and looks for trends in the data for a predetermined period of time to determine if the metal particles consist of large debris due to debris accumulation or failure due to normal wear. The system also determines a time interval for removing particles. The measured output signal is stored for a predetermined period of time, and the data system tracks trends in the readings to determine the amount and magnitude of particle accumulation.
The data and logic system 18 may be connected to an indicator on an operator panel that informs an operator of the condition of the part or the time to clean the particle detector. The drop in output voltage below a predetermined value and the percentage of output voltage drop can be used to form a corresponding indicator for the operator.

In the test, the measured voltage or resistance not only indicates whether metal particles are present or not, but also the magnitude of the measured voltage or resistance indicates the magnitude of the first and second magnets 26 and 28. It represents the size of metal particles that fill the space between them. The graph of FIG. 3 shows the voltage drop over time as metal particles fill the space between the magnets 26,28. The general results of a series of laboratory tests are shown in FIG. The phantom line shows the accumulation of normal wear debris (less than 20 microns) buildup that can be monitored and the output readings trended to determine when to clean the particle detector. For normal wear debris,
The voltage drop increases over time. In a second series of tests, metal particles ranging in size from about 100 to 250 microns were employed. The results of the second series of tests are shown by the dashed lines, indicating that the voltage drop is faster over time than normal wear debris. In a third series of tests, about 250 to 400
Metal particles in the micron range (failure type) were employed. The results of the third series of tests are shown by solid lines,
It is shown that the voltage drop increases over time. From these lines it can be seen that the rate of voltage drop is larger for large particles. Thus, the slope of the voltage drop curve will indicate the relative size of the particles collected by the detector. The data recorder and logic system can trend these output readings to determine the type of component wear (normal or critical) and the time interval for cleaning the detector.

In operation with reference to the figures, the present invention is adapted to detect metal particles which have been generated either due to normal wear or component failure. Also relevant are systems that can distinguish between normal wear conditions and the onset of component failure. In the present invention, the particle detector 14 has the second end 2.
4 threaded around the part. The first end 22 including the first and second magnets 26 and 28
It is located within the fluid of the component and is adapted to collect metal particles. The particles are detected by a module 46 that fills the space between the first and second magnets 26, 28 and creates a voltage drop. The signal from module 46 is sent to data system 18 and stored and maintained for a length of time probing for data trends. Information from the trend is used to determine the condition of the part and the time to clean the particle detector. An estimate of the particle size can be estimated from this data.

[0011] Aspects, objects and advantages of the present invention can be obtained from a study of the drawings, the disclosure and the appended claims.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a particle detector known in the art.

FIG. 2 is a schematic electronic circuit diagram according to the invention.

FIG. 3 is a graph of an exemplary test trend for a particle sensor according to the present invention.

[Sign]

 12 parts 14 particle detector 15 monitoring means 16 electric circuit 20 housing 24 second end 26 first magnet 28 annular magnet 36, 44 resistor

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Chandra Sekar Ramamuati, Illinois, United States 60563 Neyperville South 655 Vista Circle 5 (72) Inventor John Jay Clone, Illinois, United States 61525 Dunlop Brentwood 1409 (72) Inventor Ernest A Lake United States Illinois 61611 East Peoria East Autumn Lane 136

Claims (6)

[Claims] 1. A particle detector disposed within a component for detecting metal particles in a fluid and including a first magnet and a second magnet spaced apart from each other; Monitoring the voltage change across the space between the magnets to distinguish between normal wear debris accumulation and debris due to a major failure, probing the voltage change trend to determine the time to clean the particle detector, Means for distinguishing between normal wear debris and larger particles, and a device for detecting metal particles in the fluid of the part provided with. 2. Apparatus according to claim 1, including a power supply having a value of 8 volts. 3. The apparatus according to claim 1, wherein said monitoring means includes a resistor disposed between said power supply and said particle detector. 4. The device according to claim 3, wherein said resistor has a value of 18 kOhm. 5. The method according to claim 1, wherein the particle detector is configured to detect when the particles do not fill the space between the first and second magnets.
4. The device of claim 3, wherein the output voltage has a maximum output of volts and the output voltage decreases at a predetermined rate over time according to the size of the particles filling the space. 6. A method for collecting the metal particles in the fluid using a particle detector having a first magnet and a second magnet separated from each other, and forming a space between the first and second magnets. Filling with the collected metal particles, monitoring the voltage when the metal particles fill the space between the magnets, providing a voltage output signal for the amount and size of the collected metal particles, Storing over a predetermined period of time to determine if the collected metal particles are a normal accumulation of wear debris or a large piece of a failure type, and to clean the particle detector from trends in the voltage output signal. A method for detecting metal particles in a component having a fluid, comprising: determining a time.