U.S. patent application number 14/140342 was filed with the patent office on 2014-05-15 for active filtering of oil.
This patent application is currently assigned to Voelker Sensors, Inc.. The applicant listed for this patent is Voelker Sensors, Inc.. Invention is credited to Joe Hedges.
Application Number | 20140130900 14/140342 |
Document ID | / |
Family ID | 46489711 |
Filed Date | 2014-05-15 |
United States Patent
Application |
20140130900 |
Kind Code |
A1 |
Hedges; Joe |
May 15, 2014 |
ACTIVE FILTERING OF OIL
Abstract
Fuel contamination in oil is measured by using a sensor in
contact with oil whereby fuel intrusion into the oil will change
the electrical, mechanical, and/or chemical properties of the
material as compared to the same electrical, mechanical, and/or
chemical properties of the material when in contact only with
mineral or synthetic oil only. The oil quality sensor provides
real-time feedback so that an oil monitoring system can actively
remove contaminates and/or increase an additive package as
necessary.
Inventors: |
Hedges; Joe; (Portola
Valley, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Voelker Sensors, Inc. |
Palo Alto |
CA |
US |
|
|
Assignee: |
Voelker Sensors, Inc.
Palo Alto
CA
|
Family ID: |
46489711 |
Appl. No.: |
14/140342 |
Filed: |
December 24, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13212174 |
Aug 17, 2011 |
8614588 |
|
|
14140342 |
|
|
|
|
12857747 |
Aug 17, 2010 |
8643388 |
|
|
13212174 |
|
|
|
|
12426956 |
Apr 20, 2009 |
7928741 |
|
|
12857747 |
|
|
|
|
11676738 |
Feb 20, 2007 |
7521945 |
|
|
12426956 |
|
|
|
|
61374350 |
Aug 17, 2010 |
|
|
|
60774749 |
Feb 17, 2006 |
|
|
|
60782959 |
Mar 15, 2006 |
|
|
|
Current U.S.
Class: |
137/334 |
Current CPC
Class: |
G01N 33/2888 20130101;
Y10T 137/6416 20150401; F16L 53/30 20180101 |
Class at
Publication: |
137/334 |
International
Class: |
F16L 53/00 20060101
F16L053/00 |
Claims
1. A non-transitory computer readable storage medium having
embodied thereon a program executable by a processor to perform a
method for measuring oil quality, the method comprising: sensing
oil quality by way of one or more sensors in communication with a
monitoring device; measuring one or more properties of the oil; and
initiating an automated action to actively increase the quality of
the oil when the measurement indicates that the oil quality is
below an oil quality threshold.
2. The non-transitory computer readable storage medium of claim 1,
the program being further executable to activate an indicator
reflecting a recommendation that the oil be changed when the oil
quality is below an oil quality change threshold.
3. The non-transitory computer readable storage medium of claim 1,
wherein the automated action increases the quality of the oil by
turning on a heater when the oil quality is below a heater quality
threshold and then turning off the heater when the oil quality
surpasses the heater quality threshold.
4. The non-transitory computer readable storage medium of claim 1,
wherein the automated action increases the quality of the oil by
turning a vacuum on when the oil quality is below a vacuum
threshold and then turning off the vacuum when the oil quality
surpasses the vacuum threshold.
5. The non-transitory computer readable storage medium of claim 1,
wherein the automated action increases the quality of the oil by
replenishing a contaminate removing additive in the oil when the
oil quality is below a replenish contaminant removing additive
threshold.
6. The non-transitory computer readable storage medium of claim 1,
wherein the automated action increases the quality of the oil by
filtering the oil when oil quality is below a filter threshold and
then deactivating the filter filtering the oil when the oil quality
surpasses the filter threshold.
7. The non-transitory computer readable storage medium of claim 1,
the program being further executable to: measure a first set of
properties of the oil; measure a second set of properties of the
oil, wherein the second set of properties of the oil includes the
same properties as the first set of properties of the oil plus at
least one additional property of the oil not contained in the
measurements of the first set of properties of the oil; and perform
a differential analysis comparing the measured first set of
properties relative to the measured second set of properties of the
oil.
8. The non-transitory computer readable storage medium method of
claim 1, the program being further executable to: measure one or
more properties of a finely filtered portion of oil, the finely
filtered portion of oil having been filtered with a fine filter;
and perform a differential analysis comparing the measured the one
or more properties of the oil relative to the measured the one or
more properties of the finely filtered portion of oil.
9. The non-transitory computer readable storage medium of claim 1,
the program being further executable to communicate sensor data and
analyzed data to an external computing device.
10. The non-transitory computer readable storage medium of claim 9,
wherein the sensor data and analyzed data are communicated to the
external computing device through a wireless network.
11. The non-transitory computer readable storage medium of claim 9,
wherein the sensor data and analyzed data are communicated to the
external computing device through a wire trace.
12. The non-transitory computer readable storage medium of claim 9,
wherein the sensor data and analyzed data are communicated to the
external computing device through a cable.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation and claims the
priority benefit of U.S. patent application Ser. No. 13/212,174
filed Aug. 17, 2011, now U.S. Pat. No. 8,614,588, which claims the
priority benefit of U.S. provisional application 61/374,350 filed
Aug. 17, 2010. U.S. patent application Ser. No. 13/212,174 is a
continuation-in-part and claims the priority benefit of U.S. patent
application Ser. No. 12/857,747 filed Aug. 17, 2010, which is a
continuation-in-part and claims the priority benefit of U.S. patent
application Ser. No. 12/426,956 filed Apr. 20, 2009, now U.S. Pat.
No. 7,928,741, which is a continuation and claims the priority
benefit of U.S. patent application Ser. No. 11/676,738 filed Feb.
20, 2007, now U.S. Pat. No. 7,521,945, which claims the priority
benefit of U.S. provisional application Nos. 60/774,749 filed Feb.
17, 2006 and 60/782,959 filed Mar. 15, 2006. The disclosures of the
aforementioned applications are incorporated herein by
reference.
[0002] The present application is related to U.S. patent
application Ser. No. 08/176,393 filed Dec. 30, 1993, now U.S. Pat.
No. 5,435,170, U.S. patent application Ser. No. 08/730,109, now
U.S. Pat. No. 5,777,210, and U.S. patent application Ser. No.
08/637,878, now U.S. Pat. No. 5,789,665. The disclosures of the
aforementioned applications are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention generally relates to detecting
contamination in lubricating oil. More specifically, the present
invention relates to active filtering of oil in order to detect
contamination that might otherwise result in catastrophic failure
of engine or other moving parts.
[0005] 2. Description of the Related Art
[0006] Contamination in crankcase oil decreases the lubricating
ability of oil and will lead to engine failure. If a fuel injector
becomes stuck in the open position, the introduction of large
amounts of fuel in crankcase oil will decrease the viscosity of the
oil. If the fuel contamination goes undetected, the decrease in
viscosity will cause a loss of hydrodynamic lubrication resulting
in metal to metal contact and ultimately causing spun and/or seized
bearings.
[0007] Current methods for fuel detection include absorption
spectroscopy, viscosity, and the use of a `sniffer` to measure the
aromatics in the gas above the oil.
[0008] Fuel contamination can be detected using absorbance
spectroscopy, but the method has been developed for bench top
measurements after a sample of oil has been removed from the
crankcase.
[0009] Alternatively, and in the absence of other contaminants in
the oil or chemical changes to the oil, fuel (in large enough
quantities) can be detected by measuring the viscosity of the oil
by comparing to the original oil viscosity. However, oil wear,
water contamination, and soot contamination all cause an increase
the viscosity of the oil making the specific detection of fuel
contamination in oil by measuring its viscosity difficult.
[0010] A sniffer requires constant calibration with a known
fuel/oil mixture which is impractical in an in-situ device. Still
further, fuel does not significantly change other measurable
qualities of the oil (conductivity, dielectric constant,
resistance, capacitance, polarity, TAN, TBN etc) so a direct
in-situ electrical or chemical measurement of the oil to detect the
presence of fuel is difficult.
[0011] All of the foregoing methodologies are not suitable to `on
the fly` or `real time` detection. A solution is needed that
provides real-time feedback so that a system may determine the
presence of contaminates that need to be removed from the oil
and/or the need to introduce additive packages to the oil being
monitored.
SUMMARY OF THE PRESENTLY CLAIMED INVENTION
[0012] An oil quality sensor is introduced to an oil monitoring
system for the purpose of providing real-time feedback so that the
oil monitoring system can actively remove contaminates and/or
increase an additive package as necessary. A filter allows for
removal of unwanted liquids through active methods including the
application of heat or the introduction of a vacuum in response to
the real-time feedback. The heat or vacuum application is applied
as needed and in real-time based on the feedback condition of the
contaminate as measured by the quality sensor. Additives may also
be introduced in real-time based on the feedback data.
[0013] Contamination may be measured with respect to an electrical,
mechanical, and/or chemical property of a material in contact with
oil. The measured electrical, mechanical, and/or chemical property
of the material in contact with the oil is compared against a
previously measured electrical, mechanical, and/or chemical
property of the same material. A change is identified in the
measured electrical, mechanical, and/or chemical property against
the previously measured electrical, mechanical, and/or chemical
property, wherein the change indicates fuel intrusion into and
contamination of the oil. The measurement occurs in real-time (or
near real-time) as generates data that may effectuate the removal
of the contaminate or introduction of an additive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates the wear of oil due to oxidation and heat
whereby the oil becomes more polar as is known in the prior
art.
[0015] FIG. 2 illustrates an exemplary real-time oil monitoring
system.
[0016] FIG. 3 illustrates an exemplary embodiment of a sensing
element and an inset reflecting the installation of the sensing
element in an oil pan.
[0017] FIG. 4 illustrates the oil degradation cycle.
[0018] FIG. 5A illustrates a polymeric bead interaction in a
non-polar oil solution representative of relatively low
conductivity.
[0019] FIG. 5B illustrates a polymeric bead interaction in a polar
oil solution representative of relatively high conductivity.
[0020] FIG. 6A illustrates a single hydrophilic, polystyrene bead
in an environment without `free` water and reflecting relatively
low conductivity.
[0021] FIG. 6B illustrates a single hydrophilic, polystyrene bead
in an environment with `free` water and reflecting relatively high
conductivity.
[0022] FIG. 7 illustrates an exemplary interface as may be used
with a monitoring device in an oil monitoring system.
[0023] FIG. 8 discloses a method for measuring fuel contamination
in oil.
DETAILED DESCRIPTION
[0024] FIG. 1 illustrates oil that, initially, is clean and
non-polar. In the presence of O.sub.2 and heat, the oil begins to
degrade. This application of O.sub.2 and heat would occur through,
for example, the normal and ongoing use of the oil in an
automobile. This partially degraded oil, as also shown in FIG. 1,
begins to take on polar characteristics. Through the continued
application of O.sub.2 and heat, the oil becomes even more degraded
and takes on even greater polar characteristics as further shown in
FIG. 1. Increased polarity causes the oil to change is dielectric
constant, which in turn leads to increased capacitance.
[0025] FIG. 2 illustrates an exemplary real-time oil monitoring
system 200 as may be implemented in accordance with an embodiment
of the present invention. An embodiment of the oil monitoring
system 200 may comprise a monitoring device 210 for receiving and
analyzing data generated by a sensing element 220, which is in
contact with the oil or other fluid under observation.
[0026] Data generated by the sensing element 220 may be
communicated in real-time or near real-time to the monitoring
device 210 via a sensor signal cable 230. Sensor signal cable 230,
in one embodiment of the present invention, is an RS-232 compliant
serial cable wherein one end of the cable is configured to exchange
data with the monitoring device 210 and the opposite end of the
cable is configured to interface with sensing element 220 as is
discussed in greater detail in FIG. 3. Other data cables are within
the scope of the present invention subject to proper configuration
to allow for interface with the sensing element 220 and monitoring
device 210.
[0027] Monitoring device 210 may be further communicatively coupled
to an external computing device 250 such as a laptop computer, a
PDA or other mobile computing device that may be specially
configured for use with the oil sensing element 220 and monitoring
device 210. While mobility of the external computing device 250 may
be preferred in some environment (e.g., a garage), it is within the
scope of the present invention for the external computing device
250 to be a less-portable computing device such as a dedicated
workstation or desktop computer. Data may be exchanged between the
monitoring device 210 and external computing device 250 through,
for example, an external data cable 240 or a wireless network
connection.
[0028] External data cable 240 may comply with any number of data
transmission standards including Universal Serial Bus (USB) and
IEEE 1394 in addition to being a parallel or serial data cable. In
some embodiments of the present invention, monitoring device 210
may be configured for the introduction of, for example, a PCMCIA
wireless card or other wireless network adapter. In such an
embodiment, the monitoring device 210 may communicate data gathered
from the sensing element 220 as well as data analyzed by the
monitoring device 210 wirelessly using, for example, the 802
wireless data standards to external computing device 250 such that
external data cable 240 is no longer necessary.
[0029] A wireless configuration of this nature would allow
increased mobility of the monitoring device 210 while still
allowing, for example, for the storage of oil data in a centralized
repository such as the aforementioned external computing device
250. Storage of oil measurement data and analyses of that data may
be useful in determining if a particular vehicle or combustion
engine might be suffering from engine damage or some other defect
in that the particular vehicle or engine prematurely degrades oil.
Such information may be reflected by a series of oil analyses
conducted over time. These analyses may be stored, further
analyzed, and graphically illustrated in a report or some other
organized information presentation generated by external computing
device 250. It should be noted that the presence of an external
computing device 250 is not required for the operation of the
monitoring device 210 in conjunction with sensing element 220.
[0030] The monitoring device 210, in one embodiment of the present
invention, receives and displays data indicative of the status of
the oil or another fluid under observation and analysis. The
interface of monitoring device 210 is discussed in more detail in
FIG. 7 below. In another embodiment, the monitoring device 210
facilitates the real-time processing of data so that the oil
monitoring system can actively remove contaminates and/or increase
an additive package as necessary. The monitoring device 210 may
operate in conjunction with a filter to allow for removal of
unwanted liquids through active methods including the application
of heat or the introduction of a vacuum in response to the
real-time feedback. The heat or vacuum application is applied as
needed and in real-time based on the feedback condition of the
contaminate as measured by the quality sensor. Additives may also
be introduced in real-time based on the processed feedback
data.
[0031] Monitoring device 210 and certain devices coupled to device
210 may be powered by a variety of electrical power sources. In one
embodiment of the present invention, monitoring device 210 may be
electrically coupled to an AC transformer 260. In another
embodiment of the present invention, monitoring device 210 may be
electrically coupled to a DC transformer such as a cigarette
lighter adaptor whereby the system 200 may be used `on-the-road`
through use of an automobile's cigarette lighter power outlet.
Monitoring device 210 may further be powered by a replaceable or
rechargeable battery pack (not shown).
[0032] Monitoring device 210 may also be installed as a part of an
overall vehicle monitoring system or some other computing device
installed within or operating in conjunction with a motor vehicle,
engine assembly, or other mechanical device requiring the presence
of oil lubricants. The monitoring device 210 may be implemented
through software executed by a processing device; the software
being stored in a non-transitory computer readable storage medium
as is known in the art.
[0033] The monitoring device 210 may also comprise or operate in
conjunction with a thermistor to compensate sensor readings for
thermal variations. For example, in one embodiment of the present
invention, the system 200 may only operate at engine operating
temperatures in excess of, for example, 70 degrees Celsius as the
conductivity of certain oils may be completely masked by the
additives below that temperature. Additionally, because oil is
formulated to work at automotive operating temperatures, the oil
may not properly lubricate at lower temperatures thereby distorting
data gathered by the sensing element 220.
[0034] FIG. 3 illustrates an exemplary sensing element 300 for use
in real-time monitoring and filtering of oil. The inset of FIG. 3
reflects the sensing element 300 having been installed in an oil
pan. Sensing element 300 comprises an electrically nonconductive
housing 310 with three chambers (320, 330, and 340). Examples of
non-conductive materials for constructing the housing 310 include
but are not limited to ceramic, glass, plastic, woven fiberglass,
and paper impregnated with phenolic resin (e.g., Pertinax).
[0035] In some embodiments of the present invention, the housing
310 may be constructed of an electrically non-conductive material.
In other embodiments, the housing 310 may instead be constructed of
one or more materials (which may or may not be electrically
non-conductive) and subsequently coated with an electrically
non-conductive material such as a non-conductive resin cured with
ultraviolet light and/or heat. In addition to non-conductive
resins, other suitable coating materials include but are not
limited to tape, paints and hot melt adhesives.
[0036] Housing 310 may be mounted in a conventional drain plug 350
such that the sensing element 300 may be installed in a
conventional oil part of an internal combustion engine. Mounting of
the housing 310 may occur utilizing various industrial glues,
sealants, adhesives or other means so long as such mounting means
do not interfere with the sensing element 300's ability to
communicate with cable connector pins 360 as discussed in greater
detail below.
[0037] By mounting the housing 310 of the sensing element 300 in a
conventional drain plug 350, an embodiment of the present invention
may be installed in older automobiles or equipment utilizing a
combustion engines without the need for extensive retrofitting as
the drain plug 350 may simply be threaded into the oil pan's drain
hole as would occur when changing the oil of a car. An embodiment
of drain plug 350 used for mounting the housing 310 of the sensing
element 300 may utilize 1/2''.times.20 threading such than an
exemplary sensing element 300 measuring approximately 2.8'' in
length occupies an internal depth of approximately 1.8''.
[0038] The particular mechanical interface (e.g., shape and
threading specifications) of the aforementioned drain plug 350 are
exemplary as are the particular dimensions of the sensing element
300. The drain plug 350 may utilize any variety of physical
configurations (e.g., hex nut) and threading arrangements and may
further be specially manufactured for particular combustion
engine/oil pan/engine environments. The sensing element 300 (as a
part of or independently of the drain plug 350) may also utilize
any variety of O-rings, washers, and/or protective housings in
order to properly protect the sensing element 300 and to otherwise
ensure that housing 310 is properly secured within the drain plug
350.
[0039] One of the three chambers of sensing element 300 (e.g.,
chamber 320) is open. Chamber 320 detects the conductivity of the
oil directly. With regard to chamber 320, conductivity is dominated
by the ionic characteristics of oil additives (oxidation 410) as is
shown in the oil degradation cycle depicted in FIG. 4. In the oil
degradation cycle of FIG. 4, as additives are depleted the
additives become less polar; as the base oil itself deteriorates,
the base oil becomes more polar.
[0040] Returning to FIG. 3, the remaining two chambers (chambers
330 and 340) are covered by a conductive mesh screen (390a and
390b). Chamber 330 comprises (houses) a matrix of insoluble
polymeric beads (not shown). Chamber 340 comprises a single bead
(not shown). The conductive mesh screen (390a and 390b) may be
constructed of stainless steel cloth.
[0041] In a non-polar solution with relatively low conductivity,
the beads in chamber 330 remain separate from one another as is
shown in FIG. 5A. It should be noted that in FIG. 5A as well as
FIG. 5B--for the sake of simplified illustration--only a single
monolayer of the charged bead matrix is shown. The fact that only a
single monolayer is illustrated should not be interpreted as
otherwise limiting the present disclosure. As the oil's polarity
increases, however, the conductivity across the matrix increases
and the ionic component of each group of beads relaxes and begins
electrically interacting with an adjacent group in the presence of
voltage potential. FIG. 5B illustrates the same whereby the beads
form a bridge on the conductive mesh 390a of the chamber 330. The
change in the bead matrix as illustrated in FIGS. 5A and 5B
indicates both additive depletion and oxidation and is represented
graphically by line 420 (additive depletion) in FIG. 4.
[0042] The sensing element 300 generates a sensor reading
reflective of oxidation based on a differential measurement of a
matrix of insoluble polymeric beads and the oil being analyzed.
Sensing element 300 further generates a sensor reading reflective
of the presence of soot and similar contaminants based on a
differential measurement of oil inside a filter and the oil being
analyzed. Sensing element 300 further generates a sensor reading
reflective of the presence of fuel, water or similar contaminants
based on a differential measurement of a matrix of insoluble
polymeric beads and the contaminated oil being analyzed. The
sensing element 300 may measure oil quality through the use of any
one of a number of different electrical forms including alternating
current (AC), direct current (DC), a combination of AC/DC, in
addition to mechanical forms such as crystal resonance. By
utilizing sensor readings from the three chambers of the sensor
array, an accurate measurement of oxidation, additive depletion,
and contamination is provided, which is more accurate reflection of
oil quality. This data may be generated and reported in real-time
(or near real-time).
[0043] Data readings from open chamber 320 are subtracted from data
readings obtained from the bead matrix in chamber 330. This
subtraction of data may take place in a differential analysis
software module (not shown) in monitoring unit 210 under the
control of a microprocessor (also not shown). This differential
analysis may take place in real-time or near real-time.
[0044] Various other hardware and software elements may be present
in monitoring unit 210 to allow for the receipt, processing,
analysis, storage, and/or exchange of data. For example, one
embodiment of the present invention may utilize an application
specific integrated circuit (ASIC) for undertaking the differential
analysis otherwise performed by the aforementioned software module.
Through the real-time or near real-time subtraction of the open
chamber 320 data, effects of additives are removed from the
analysis and only oxidation is measured. In this regard, no
calibration of the system 200 is required and any differences in
various oil formulations are negligible with regard to a
determination of oxidation in the oil under analysis.
[0045] This differential measurement technique may be used to
determine the polarity of oil where one chamber measures multiple
properties of the oil and a second chamber measures the same
properties with the exception that it does not measure the polarity
of the oil. Taking a differential measurement between the two
chambers allows for a determination of the polar condition of the
oil. Specifically, if an electrical measurement of the oil is made
and a second electrical measurement is made of an ionic polystyrene
matrix where the electrical signal includes components from both
the oil and the polystyrene matrix then the difference between the
signals shows the polarity of the oil.
[0046] Chamber 330 may determine soot contamination in an oil
sample wherein the sensing element 300 has been disposed. This
determination may similarly take place in real-time or near
real-time. Soot particulates consist primarily of carbon and tend
to bind to one another and to the actual engine. If soot is allowed
to aggregate unfettered, the soot particulates can actually begin
to score the engine bearings. Soot measurement is based on a
percentage of the amount of soot freely available in the oil and is
commonly referred to as the saturated relative contamination. A
given amount of free soot can, in some instances, constitute 1% to
2% contamination for base oil without additives or greater than 7%
for fully formulated oils.
[0047] When a soot dispersant additive begins to fail, the soot
begins to adhere to the surface of the aforementioned polymeric
beads and form a bridge across the chamber 330. When such a bridge
occurs, sensor readings at chamber 330 change dramatically and
continue to increase as more layers of carbon soot accumulate.
Conductivity caused by soot is considerably greater than that due
to oil and additive polarity and is measurable by the present
sensing element 300 in addition to capable of being differentiated
versus worn oil.
[0048] Soot contamination may be determined using a differential
measurement. By using two chambers--one that measures the
properties of the oil and the other that measures the properties of
the oil after it has passed thru a fine filter that keeps soot or
any other contaminates away from the sensor--soot contamination can
be measured. Specifically, soot that is not chemically capped is
electrically conductive. Taking the differential measurement of two
chambers where one measures all the electrical characteristics of
the oil and the other is precluded from measuring the effect of the
soot (or any other particle) in the oil by a 0.2 micron filter
allows for a determination of soot contamination. This technique is
not limited to an electrical measurement; it could also be used in
an optical measurement. In response to these measurements,
additives may be introduced in real-time or near real-time before
any damage to the engine or operating environment is incurred.
[0049] The third chamber--chamber 340--may detect water
contamination in the oil or fluid under investigation. Water that
enters the engine and boils as a result of engine temperature can
cause the engine oil to turn into a sludge-like substance. This
sludge-substance not only fails to properly lubricate various
engine components but can also rust an engine from the
inside-out.
[0050] A real-time or near real-time determination of water
contamination in oil may be made using a differential measurement
technique. By immersing two sensor chambers into the oil--one that
measures multiple properties of the oil and the other measures
multiple properties less the property associated with water
contamination--and using a differential technique, the water
contamination may be independently measured. Specifically, if an
electrical measurement of polystyrene matrix is made where the
matrix is relatively insensitive to water contamination and the
signal is compared to a measurement of the polystyrene matrix that
is highly sensitive to water absorption, the difference between the
measurements will allow the water contamination to be measured.
[0051] The measurement may be made electrically or mechanically by
looking at the change in electrical characteristics of the beads or
by looking at the change in physical characteristics of the beads.
Using a highly cross-linked polystyrene matrix will limit both the
mechanical and electrical changes to the bead matrix. Using a
loosely cross-linked polystyrene bead matrix will allow for large
changes in the electrical and mechanical properties of the beads.
The change is proportional to the quantity of water
contamination.
[0052] Conventional methodologies report water in oil as a
percentage of total volume. Different blends of oil, however, can
consume varying amounts of water as a result of oil additives
binding with water molecules. As such, an absolute measure of water
it not necessarily helpful or informative. An embodiment of the
present invention reports water content as a percent saturated
relative humidity (SRH) of the oil. An SRH of, for example, 100%
where the oil cannot absorb any more water without its dropping out
of solution as emulsified or free water is the same for all oils at
a given temperature.
[0053] As noted above, a single polystyrene bead in chamber 340
measures water contamination corresponding to 2% SRH. The diameter
of the bead is slightly less than the thickness of the sensor
housing/sensor board 310. The bead is extremely hydrophilic and
attracts water, swells and physically contacts the conductive mesh
screen 390b of the chamber 340. The resulting increase in
conductivity is detected as shown in FIGS. 6A and 6B.
[0054] FIG. 6A illustrates a single hydrophilic, polystyrene bead
in an environment without `free` water and reflecting relatively
low conductivity. FIG. 6B, however, illustrates the same single
hydrophilic, polystyrene bead in an environment with `free` water
(i.e., water contamination) whereby the bead swells through its
attracting of the `free` water and comes into contact with camber
340's conductive mesh 390b thus reflecting relatively high
conductivity.
[0055] The polystyrene beads of the present invention may be
impregnated with charged groups. In one exemplary embodiment,
sodium and sulfite may be utilized as the cation and anion,
respectively. Salts of polyatomic anions such as phosphates and
carboxylates may also be utilized as cation exchange groups.
Additionally, anionic exchange groups may comprise salts of
N-alkylated amines. The beads may be cross linked with 8%
divinylbenzene and further comprise a titer or exchange capacity of
1.7 meq/ml. The beads, further, may be of 1.180 to 38.mu.m in
diameter; 500 mg of which being sufficient in the present invention
although lesser (and greater) amounts are possible in the practice
of the present invention (e.g., 20 mg).
[0056] The beads utilized in various embodiments of the present
invention may be pre-treated or `prepared` in order to create a
polar environment that allows for more accurate measurement of
conditions in a non-polar environment such as uncontaminated oil
solutions.
[0057] Such a process may include washing the beads with 1N sodium
hydroxide for approximately 15 to 30 minutes at room temperature;
the excess sodium hydroxide is washed off in a methanol bath. The
beads are further soaked in methanol to remove any excess water and
then air dried to remove any remaining methanol. The beads are
subsequently soaked in glycerol for approximately 24 hours and then
heated to approximately 140 degrees Celsius for approximately two
hours to ensure proper penetration of the glycerol. At this point,
the beads are fully swollen.
[0058] The beads are then placed in a non-polar fluid (e.g., clean
oil) and again heated to 120 degree Celsius to remove excess
ethylene glycol and to further `shrink` the beads to a `clean oil`
state. The beads are then loaded into the various chambers (e.g.,
330 and 340) of the sensing element 300. The beads are typically
loaded into the various chambers (e.g., 330 and 340) of the sensing
element 300 under slight to moderate pressure such that the beads
are in close proximity to one another. In an alternative
embodiment, the beads may be further soaked in glycerol to cause
slight expansion of the beads and otherwise obtain bead-to-bead
proximity.
[0059] Data readings from sensing element 300 are communicated to
the monitoring device 210 of system 200 through any number of wire
tracings 380 on/in the non-conductive housing 310 of element 300.
These communications occur in real-time or near real-time. The
conductive pathways of the wire tracings 380 are, in some
embodiments, etched from copper sheets laminated onto the
non-conductive housing 310. In other embodiments, traces may be
added through electroplating. Various other methodologies for
creating the conductive wire tracings 380 on the non-conductive
housing 310 including but not limited to silk screen printing,
photoengraving, and milling. In some embodiments of the present
invention, a series of layers of substrates may make up the
non-conductive housing 310 and a series of blind and/or buried vias
(not shown) may be used instead of (or in addition to) surface
mount methodologies.
[0060] These conductive pathways are coupled (e.g., through
soldering) to chambers 310-340 in addition to output connectors
370, which (in one embodiment of the present invention) extend
outward from the drain plug 350 and toward the various elements on
the face of the non-conductive housing 310 of sensing element 300.
Output connectors 370 serve to couple the wire tracings 380 on the
face of the non-conductive housing 310 to cable connector pins 360
which extend outward from the drain plug 350 (and away from the
non-conductive housing 310) such that the connector pins 360 may be
connected to sensor signal cable 230 for real-time or near
real-time data exchanges with monitoring device 210. In this way,
data generated at the various chambers 310-340 may be communicated
through wire tracings 380 to the output connectors 370, which
connect to cable connector pins 360.
[0061] In some embodiments, output connectors 370 and cable
connector pins 360 may be the same uninterrupted element whereby
the pins 360 extend through the drain plug housing 350 and toward
the non-conductive housing 310 where one end of the connectors are
soldered to the wire tracings 380. In additional embodiments of the
present invention, that portion of the drain plug 350 most distant
from the oil pan or chamber into which the non-conductive housing
310 is inserted may have a concave design such that the cable
connector pins 360 are partially or entirely housed within the
concave area and protected from damage through exposure to the
elements that might corrode the face of the pins 360 or deform the
shape of the pins 360 (e.g., bending) through impact or other
applied forces.
[0062] FIG. 7 illustrates an exemplary interface 700 as may be used
with a monitoring device 210 of an exemplary embodiment of the
presently disclosed oil monitoring system 200. After the
aforementioned differential analysis software module of the
monitoring device 210 has undertaken an analysis of the oil data
from sensing element 220, the data is displayed in an informative
format for the user of system 200.
[0063] For example, overall oil quality may be reflected by one of
a series of light emitting diodes (LEDs) 710 in the monitoring
device 210. Various levels of oil quality may be reflected although
the present embodiment reflects levels of <good>, <ok>,
<fair>, and <change>. The latter
setting--<change>--indicates the poor quality of the oil
under analysis and the need for a change of the same.
[0064] A similar LED may be utilized to reflect the presence of
excess and unwanted soot in the oil under analysis (LED 720) as
well as excess and unwanted water (LED 730). These indicators, too,
may further or individually reflect the need to replace motor oil
before damage to the engine environment ensues. An overall system
status LED 740 indicates that the monitoring device 210 and related
equipment is in overall working order and that `false positives`
reflecting inaccurate oil readings are not being generated.
[0065] In another embodiment of the present invention, the
interface 700 of the monitoring device 210 may reflect a variety of
graphical outputs. For example, oil quality may be reflected by an
LED or digital image output bar that rises or falls based on the
oil quality. Oil quality may also be reflected by a digital output
reflecting a number indicative of oil quality such that increased
quality accuracy is possible.
[0066] In some instances, the monitoring device 210 may not include
an interface. The monitoring device 210 may simply react to the
measured data in real-time or near real-time through the activation
of a proper filtering technique and/or the introduction of an
additive as is appropriate. As noted above, in some instances, the
monitoring device 210 may not be a device at all and may simply be
implemented in a software application.
[0067] Data generated as a result of various oil measurements
reflects the overall quality of the oil. For example, normal oil
capacitance and normal oil conductivity in conjunction with no
water absorption is generally an indicator of overall good oil
quality. To the contrary, high oil capacitance, low oil
conductivity in conjunction with no water absorption may indicate
worn oil quality. Low capacitance and low conductivity of the oil
may be reflective of additive depletion. Soot contamination and
water contamination may be reflected by rapid increases in oil
capacitance notwithstanding normal oil conductivity in conjunction
with a lack of water absorption and the presence of water
absorption, respectively.
[0068] Various differential measurement outputs (or specific
measurements or ranges of measurement) may be correlated to the
aforementioned interface outputs (i.e., good v. change; graphical
bars; numerical output). In some embodiments, this information may
also or, alternatively, be reflected at the external computing
device 250.
[0069] In some embodiments of the present invention, a series or
array of oil sensors 220 may be utilized. The collective
measurement data is analyzed by a signal monitoring device 210 or
may be collected by individual monitoring device 210 and
subsequently conveyed to the external computing device 250. Through
collection and analysis of oil quality data from a series or array
of oil sensors 220, an even more accurate oil quality reading may
be obtained in that irregular and/or inaccurate oil readings (e.g.,
spikes in data) may be identified and filtered out of the final oil
quality analysis. The collective measurement data may be, for
example, batched and collectively analyzed or serially analyzed as
data becomes available. Parallel analysis of portions of the oil
measurement data may also take place.
[0070] While the present invention has been described in connection
with a series of exemplary embodiments, these descriptions are not
intended to limit the scope of the invention to the particular
forms set forth herein. To the contrary, the present descriptions
are intended to cover such alternatives, modifications, and
equivalents as may be included within the spirit and scope of the
invention as defined by the appended claims and otherwise
appreciated by one of ordinary skill in the art.
[0071] The aforementioned differential measurement techniques may
also be used for measuring fuel contamination. Using two sensor
chambers--one that is sensitive to fuel contamination and one that
is not sensitive to fuel contamination--and taking the differential
signal between the two allows the for the detection of fuel
contamination in oil. This technique is not limited to the above
examples but can also be used to measure specific additives,
contaminates or differences in other types of base stocks. Further,
the technique is not limited to measuring electrical properties.
The technique may be used to measure a change in size of a
polymeric matrix due to a change in polarity of the oil, change in
chemical composition of the oil due to degradation or change in
size of the matrix due to contamination.
[0072] Differential inputs may include beads prepared where one
type of bead can have its ionic group influenced by metals whereas
another group will not be influenced in such a manner.
Alternatively, one group of beads may be prepared such that they
react differently than another group of beads in the presence of
fuel. Differential measurement combinations may take into account
one or more of different bead types, bead cross-linking, bead size,
and bead preparation; the ability to change the physical properties
of the sensor chambers (e.g., filters, electrode size, electrode
shape, and so forth); and electrical excitation possibilities.
[0073] Various embodiments of the present invention may be
implemented to analyze a variety of oil types and viscosities. The
present invention may be implemented to analyze fluid substances at
a variety of temperatures. The present invention may further allow
for retrofitting of older oil pans or combustion engines while
further allowing for design-specific configurations. In some
embodiments of the present invention, a sensing element may be
dedicated to a particular oil quality determination and used in
tandem with a series of other sensing elements with respect to
differential measurement of that particular quality or as part of
an array with respect to a determining a variety of qualities
utilizing various differential techniques. The present invention
may be implemented in a variety of different operating environments
including but not limited to gasoline engines, diesel engines,
transmissions, turbines, transformers, gear boxes, vacuum pumps and
other oil-reliant machinery.
[0074] Some embodiments of the present invention may employ various
means of metal detection. For example, metal detection may be
electrical; attaching a specific ion to a polystyrene bead may
allow for a specific metal or group of metals to be detected. In
one such example, one chamber of a sensor may contain beads with a
hydrogen ion while the other chamber may contain beads with a
barium ion. The sensor may be placed in an oil solution that
contains lead whereby the lead would displace the hydrogen ion and
electrically `cap` the bead so that it does not change conductivity
when polarity changes. The barium, on the other hand, would not be
affected by the lead and will change conductivity only when the oil
polarity changes. Taking the electrical differential of the signals
generated by the beads in the two chambers will provide an
indication of the lead contamination.
[0075] Metal detection may also be visible. For example, in the
presence of copper, a colorimetric change takes place when the
hydrogen ion is replaced by a copper ion. While the copper will
replace the hydrogen ion, the barium ion will not be replaced.
Measuring the differential of the visible spectra of the two
chambers may provide an indication of, in this example, copper
contamination in the oil.
[0076] Detection may also occur mechanically or
electro-mechanically. The bead size may change by, for example, 5%
when different ions are attached. Using a mechanical differential
measurement methodology may provide an indication of specific
metals. A spring or fulcrum may be used in some embodiments to show
this differential.
[0077] In a still further embodiment of the present invention, a
method for measuring fuel contamination in oil uses a material in
contact with the oil. Fuel intrusion into the oil will change the
electrical, mechanical and/or chemical properties of the material
as compared to the same electrical, mechanical, and/or chemical
properties of the material when in contact with mineral or
synthetic oil only. The measured property of the material that is
in contact with the oil/fuel mixture will change with respect to
fuel; oil will not change the property.
[0078] In such an embodiment, the material may be a plastic
comprised of a homologous polymer of polystyrene and polyphenylene
oxide, which is commercially available under the brand name Noryl.
In another embodiment, the material may be a high molecular weight
silicone paste. Noryl shows excellent tolerance for mineral oils
while showing extreme intolerance (softening) for fuel. Silicone or
fluorosilicone paste is a non-polar substance that is susceptible
to swelling and even dissolving in solvents and fuels while the
effect of mineral and synthetic oil on silicone is minimal.
[0079] The polystyrene in Noryl can be mixed with other materials
either during polymerization or post polymerization to enhance its
susceptibility to fuel and change its electrical properties. For
example, polystyrene co-polymerized and cross-linked with divinyl
benzene (DVB) can be used. The amount of DVB used during
polymerization can change how the resulting polymer reacts to oil
versus fuel. The material could be in the form of an ion exchange
resin bead (e.g., sulfonated or aminated Polystyrene/DVB) with a
chosen substance attached to the ion exchange sites where the fuel
will cause a measurable change in electrical, mechanical, or
chemical properties of the ion exchange resin bead. Silicone can be
doped with different substances to enhance its electrical
properties (e.g., resistance and capacitance), mechanical
properties (e.g., viscosity and durometry), and chemical properties
(e.g., solubility and reactivity).
[0080] The material is physically small enough to be placed in some
type of sense element that can be in contact with the fuel/oil
mixture in situ. The material could be utilized in a probe. The
material (silicone or polystyrene) could also be in the form of a
thin substrate bonded to a stiff backbone with two probes on each
side (or end) of the substrate. The probes could measure the
impedance, capacitance, or resistance of the substrate (similar to
the thin polystyrene substrate used by multiple companies to detect
water in oil by measuring the change in capacitance of the
polystyrene). The probes could be spring loaded where the substrate
disintegrates in the fuel/oil mixture and the probes would form a
hard contact.
[0081] The system could take the form of a coating that is
deposited over a conductive or semi-conductive material causing a
change in the electrical properties or mechanical properties of the
system as the physical or electrical properties of the material
change due to the change in the coating as it comes in contact with
fuel.
[0082] The material could be in the form of polymeric beads--ion
exchange-functionalized or not--where fuel intruding into the oil
causes a measurable change in the beads. The beads could be trapped
in a mesh housing allowing contact with the oil and the mesh
provides a means for measuring a chemical/electrical/mechanical
change in the beads.
[0083] FIG. 8 illustrates a method for measuring fuel contamination
in oil. In step 810, an electrical, mechanical, and/or chemical
property of a material in contact with oil is measured. In step
820, the measured electrical, mechanical, and/or chemical property
of the material in contact with the oil is compared against a
previously measured electrical, mechanical, and/or chemical
property of the same material. A change is identified in the
measured electrical, mechanical, and/or chemical property against
the previously measured electrical, mechanical, and/or chemical
property in step 830, wherein the change indicates fuel intrusion
into and contamination of the oil. The existence of this intrusion
may be reported to a user through an interface like that described
in the context of FIG. 7.
[0084] In step 840, a corrective action is taken, which may be the
implementation of an oil filtering process. Alternatively, the
corrective action may be the introduction of an additive when a
particular additive package is deemed to be low or lacking. Once
the determination is made as to the need to implement a filter or
introduce an additive, the appropriate filtering component or
additive injector is activated by way of the monitoring device
210.
[0085] While this invention has been described in conjunction with
the specific exemplary embodiments outlined above, many
alternatives, modifications, and variations may be apparent to
those skilled in the art. Accordingly, the exemplary embodiments of
the invention as set forth both are intended to be illustrative and
not limiting except as otherwise set forth in the claims.
* * * * *