U.S. patent application number 17/211388 was filed with the patent office on 2022-09-29 for lubricant dilution detection system.
This patent application is currently assigned to Caterpillar Inc.. The applicant listed for this patent is Caterpillar Inc.. Invention is credited to Andrew W. BILLING, Michael J. CAMPAGNA, Joseph L. KENNEDY.
Application Number | 20220307394 17/211388 |
Document ID | / |
Family ID | 1000006588900 |
Filed Date | 2022-09-29 |
United States Patent
Application |
20220307394 |
Kind Code |
A1 |
KENNEDY; Joseph L. ; et
al. |
September 29, 2022 |
LUBRICANT DILUTION DETECTION SYSTEM
Abstract
Lubricant dilution detection systems and methods are disclosed.
A method for detecting lubricant dilution for a lubrication system
includes detecting a shutdown event of the lubrication system. The
method includes measuring lubricant pressure during the shutdown
event. The method further includes determining lubricant dilution
based on the measured lubricant pressure during the shutdown event.
In accordance with a determination that there is lubricant
dilution, the method includes outputting an indication of the
lubricant dilution.
Inventors: |
KENNEDY; Joseph L.;
(Zionsville, IN) ; CAMPAGNA; Michael J.;
(Chillicothe, IL) ; BILLING; Andrew W.;
(Bloomington, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Caterpillar Inc. |
Peoria |
IL |
US |
|
|
Assignee: |
Caterpillar Inc.
Peoria
IL
|
Family ID: |
1000006588900 |
Appl. No.: |
17/211388 |
Filed: |
March 24, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01M 1/02 20130101; G01N
33/2888 20130101; F01M 1/18 20130101; F01M 11/10 20130101 |
International
Class: |
F01M 1/18 20060101
F01M001/18; F01M 11/10 20060101 F01M011/10; G01N 33/28 20060101
G01N033/28 |
Claims
1. A method for detecting lubricant dilution for a lubrication
system, comprising: detecting a shutdown event of the lubrication
system; measuring lubricant pressure during the shutdown event;
determining lubricant dilution based on the measured lubricant
pressure during the shutdown event; and in accordance with a
determination that there is lubricant dilution, outputting an
indication of the lubricant dilution.
2. The method of claim 1, wherein detecting the shutdown event
includes detecting a key off signal or a shutdown command
signal.
3. The method of claim 1, wherein detecting the shutdown event
includes detecting that an engine speed decreases below a
threshold.
4. The method of claim 1, further including: determining lubricant
dilution based on the measured lubricant pressure during a
plurality of shutdown events.
5. The method of claim 1, wherein determining lubricant dilution
includes: comparing the measured lubricant pressure to a threshold;
determining whether the measured lubricant pressure is less than
the threshold; and in accordance with a determination that the
measured lubricant pressure is less than the threshold, determining
lubricant dilution.
6. The method of claim 5, wherein the threshold is a variable
threshold based on engine speed.
7. The method of claim 6, further including: determining lubricant
dilution when the measured lubricant pressure is less than the
threshold for a predetermined amount of time.
8. The method of claim 1, further including determining lubricant
dilution based on the measured lubricant pressure during the
shutdown event when a value indicative of lubricant temperature is
between 65-105.degree. C.
9. The method of claim 1, wherein outputting an indication of the
lubricant dilution includes: generating recommendations for
mitigating the lubricant dilution; and outputting the
recommendations.
10. A lubricant dilution detection system, comprising: a
lubrication system; a sensor for measuring lubricant pressure in
the lubrication system; and a controller configured to: detect a
shutdown event of the lubrication system; measure lubricant
pressure during the shutdown event; determine lubricant dilution
based on the measured lubricant pressure during the shutdown event;
and in accordance with a determination that there is lubricant
dilution, output an indication of the lubricant dilution.
11. The system of claim 10, wherein detecting the shutdown event
includes the controller configured to detect a key off signal or a
shutdown command signal.
12. The system of claim 10, wherein detecting the shutdown event
includes the controller configured to detect that an engine speed
decreases below a threshold.
13. The system of claim 10, wherein the controller is further
configured to: determine lubricant dilution based on the measured
lubricant pressure during a plurality of shutdown events.
14. The system of claim 10, wherein the controller is further
configured to: compare the measured lubricant pressure to a
threshold; determine whether the measured lubricant pressure is
less than the threshold; and in accordance with a determination
that the measured lubricant pressure is less than the threshold,
determine lubricant dilution.
15. The system of claim 14, wherein the threshold is a variable
threshold based on engine speed.
16. The system of claim 15, wherein the controller is further
configured to: determine lubricant dilution when the measured
lubricant pressure is less than the threshold for a predetermined
amount of time.
17. The system of claim 10, wherein the controller is further
configured to: determine lubricant dilution based on the measured
lubricant pressure during the shutdown event when a value
indicative of lubricant temperature is between 65-105.degree.
C.
18. The system of claim 10, wherein outputting an indication of the
lubricant dilution includes the controller configured to: generate
recommendations for mitigating the lubricant dilution; and output
the recommendations on the output indicator.
19. A method for detecting lubricant dilution for a lubrication
system, comprising: detecting a shutdown event of the lubrication
system when one or more operating conditions associated with the
lubrication system decreases below a shutdown event threshold;
measuring lubricant pressure during the shutdown event; comparing
the measured lubricant pressure to a lubricant dilution threshold
determining whether the measured lubricant pressure is less than
the lubricant dilution threshold; and in accordance with a
determination that the measured lubricant pressure is less than the
lubricant dilution threshold, determining lubricant dilution; and
in accordance with a determination that there is lubricant
dilution, outputting an indication of the lubricant dilution.
20. The method of claim 19, wherein the lubricant dilution
threshold is a variable threshold based on engine speed.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to lubrication
systems, and more particularly, to a lubricant dilution detection
system for such lubrication systems.
BACKGROUND
[0002] Lubrication systems may provide one or more pressurized
lubricants to various moving components (e.g., bearings, gears,
etc.) to lubricate the components. Lubricants, such as oil, used in
the lubrication systems may become diluted over time due to various
causes. For example, liquid fuel (e.g., diesel fuel) from a fuel
system of an engine and/or coolant from an oil cooler may leak into
the lubrication system and become mixed with the lubricant.
Consequently, the viscosity, and thus the lubrication ability, of
the lubricant may be reduced. Accordingly, the moving components
may become damaged over time due the diluted lubricant. Current
methods for detecting lubricant dilution may require manually
testing the lubricant using a sample of the lubricant and/or may
not adequately detect dilution of the lubricant.
[0003] Japanese Patent Application Publication No. 2004293394,
published on Oct. 21, 2004 ("the '394 publication"), describes an
oil dilution prevention device for an engine. The oil dilution
prevention device includes means for detecting a parameter relating
to a dilution rate of the engine oil. The parameter can include
pressure of the engine oil during an idling operation of the
engine. The oil dilution prevention device of the '394 publication
detects the engine oil is diluted when the pressure of the engine
oil is equal to or less than a threshold value during the idling
condition. However, the device of the '394 publication may not
adequately detect lubricant dilution and/or may falsely diagnose
dilution of the lubricant.
[0004] The lubricant dilution detection system of the present
disclosure may solve one or more of the problems set forth above
and/or other problems in the art. The scope of the current
disclosure, however, is defined by the attached claims, and not by
the ability to solve any specific problem.
SUMMARY
[0005] In one aspect, a method for detecting lubricant dilution for
a lubrication system is disclosed. The method includes: detecting a
shutdown event of the lubrication system; measuring lubricant
pressure during the shutdown event; determining lubricant dilution
based on the measured lubricant pressure during the shutdown event;
and in accordance with a determination that there is lubricant
dilution, outputting an indication of the lubricant dilution.
[0006] In another aspect, a lubricant dilution detection system is
disclosed. The system includes: a lubrication system; a sensor for
measuring lubricant pressure in the lubrication system; and a
controller configured to: detect a shutdown event of the
lubrication system; measure lubricant pressure during the shutdown
event; determine lubricant dilution based on the measured lubricant
pressure during the shutdown event; and in accordance with a
determination that there is lubricant dilution, output an
indication of the lubricant dilution.
[0007] In yet another aspect, a method for detecting lubricant
dilution for a lubrication system is disclosed. The method
includes: detecting a shutdown event of the lubrication system when
one or more operating conditions associated with the lubrication
system decreases below a shutdown event threshold; measuring
lubricant pressure during the shutdown event; comparing the
measured lubricant pressure to a lubricant dilution threshold
determining whether the measured lubricant pressure is less than
the lubricant dilution threshold; and in accordance with a
determination that the measured lubricant pressure is less than the
lubricant dilution threshold, determining lubricant dilution; and
in accordance with a determination that there is lubricant
dilution, outputting an indication of the lubricant dilution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate various
exemplary embodiments and together with the description, serve to
explain the principles of the disclosed embodiments.
[0009] FIG. 1 is a schematic view of an engine system having a
lubricant dilution detection system, according to aspects of the
disclosure.
[0010] FIG. 2 is a schematic view of the exemplary lubricant
dilution detection system for the engine system of FIG. 1.
[0011] FIG. 3 provides a flowchart depicting an exemplary method
for detecting dilution of a lubricant for the system of FIG. 1.
[0012] FIGS. 4A and 4B are plots of lubricant pressure versus
engine speed during shutdown, according to one or more
embodiments.
DETAILED DESCRIPTION
[0013] Both the foregoing general description and the following
detailed description are exemplary and explanatory only and are not
restrictive of the features, as claimed. As used herein, the terms
"comprises," "comprising," "has," "having," "includes,"
"including," or other variations thereof, are intended to cover a
non-exclusive inclusion such that a process, method, article, or
apparatus that comprises a list of elements does not include only
those elements, but may include other elements not expressly listed
or inherent to such a process, method, article, or apparatus. In
this disclosure, unless stated otherwise, relative terms, such as,
for example, "about," "substantially," and "approximately" are used
to indicate a possible variation of .+-.10% in the stated
value.
[0014] FIG. 1 illustrates a schematic view of an engine system 10
system having a lubricant dilution detection system 100. Engine
system 10 includes an engine 12, such as an internal combustion
engine. Engine 12 may include for example, a diesel engine, a
gasoline engine, a dual fuel engine (e.g., an engine capable of
running on both gaseous fuel and/or liquid fuel), or any other type
of engine known in the art. Engine 12 may be used in power
generator applications, mobile machines (e.g., vehicles), other
types of heavy machinery or equipment, or the like. Operation of
engine 12 may produce power. For example, engine 12 may include one
or more cylinders (not shown) and a crankshaft (not shown) for
providing power to a flywheel (not shown) or the like. As shown in
FIG. 1, engine system 10 also includes a lubrication system 14, a
lubricant dilution detection system 100, and an output indicator
16. Engine system 10 may include other components and/or systems,
such as, for example, a transmission system and/or other mechanical
systems including moving and/or rotating components.
[0015] Lubrication system 14 may include a lubricant supply 18,
such as a lubricant pan, a pump 20, and a filter 22 in
communication with each other via a lubricant supply line 24 (e.g.,
lubricant gallery). The lubricant may include oil or any other type
of liquid lubricant known in the art. Pump 20 may include a
mechanical pump for pressurizing fluid (e.g., lubricant) to
generate flow of lubricant from lubricant supply 18 through
lubrication system 14. For example, pump 20 may include a gear-type
pump driven by gear trains from the crankshaft or other rotating
components of engine 12. Further, pump 20 may be driven by other
means and may include, for example, an electric driven pump, a
hydraulic driven pump, and/or any other type of pump. Pump 20 may
include a pressure regulator valve 26 for reducing and regulating a
pressure of the lubricant exiting pump 20 and lowering the pressure
to a predetermined level, as detailed further below. Valve 26 may
receive pressure signals from lubricant supply line 24 (e.g., as
shown by the dashed lines connected to valve 26), such that valve
26 is controllable by the pressure signals between an open position
and a closed position for regulating the pressure at the
predetermined level.
[0016] Lubricant supply line 24 may include a series of pipes or
passageways for supplying lubricant from lubricant supply 18 to
various components of engine 12. For example, lubrication system 14
may supply lubricant to the crankshaft, the pistons, a camshaft
(not shown), bearings (not shown), and/or any other components of
engine 12. Excess lubricant may drain back into lubricant supply
18. Filter 22 may remove particulates or other contaminants from
the lubricant to prevent the particulates or contaminants from
damaging components of engine 12. It is understood that lubrication
system 14 may include any number and/or combination of valves or
other components known in the art, such as one or more lubricant
coolers (not shown), a scavenge pump (not shown), a pressure relief
valve, and/or other types of filters (e.g., suction screen and/or
centrifugal lubricant filter). Further, while the exemplary
embodiment describes a lubrication system 14 for an engine 12, it
is understood that aspects of the disclosure may be used for
lubrication systems for any other type of mechanical system having
moving and/or rotating components (e.g., transmission systems).
[0017] Output indicator 16 may indicate lubrication dilution in
lubrication system 14, as detailed below. Output indicator 16 may
include a display, a gauge, a light, a speaker, or the like. For
example, output indicator 16 may indicate a value (numerical value,
percentage, or the like) indicative of dilution of the lubricant in
lubrication system 14 and/or may indicate (e.g., via a
notification) when the lubricant is diluted. Indicator 16 may be
located as part of engine system 10 (e.g., in an operator cab of a
mobile machine) and/or may be located remote from engine system 10.
While only a single output indicator 16 is described herein, it is
understood that output indicator 16 may include one or more
indicators and may include any type of indicator for indicating
lubricant dilution in lubrication system 14.
[0018] Lubricant dilution detection system 100 includes a
controller 104, such as an engine control module (ECM), and a
sensor system 30 connected to controller 104. Sensor system 30 may
include one or more sensors for measuring operating conditions,
such as pressure sensors, temperature sensors, flow sensors, speed
sensors, or the like. For example, sensor system 30 may include a
lubricant pressure sensor 32, an engine speed sensor 34, and/or a
lubricant temperature sensor 36. Lubricant pressure sensor 32 may
be located in lubricant supply line 24 downstream of pump 20 and
may sense values indicative of a pressure of lubricant in
lubrication system 14. Engine speed sensor 34 may be located at the
crankshaft of engine 12 and may sense values indicative of engine
speed. Engine speed sensor 34 may be located at any location of
engine 12, such as, for example, a crank pulley, the flywheel, a
camshaft, or on the crankshaft. Lubricant temperature sensor 36 may
be located in lubricant supply line 24 downstream of pump 20 and
may sense values indicative of a temperature of lubricant in
lubrication system 14. For example, lubricant temperature sensor 36
may sense a temperature of the lubricant directly. In some
embodiments, lubricant temperature sensor 36 may sense a
temperature of coolant in a cooling system (not shown) of engine
system 10. The temperature of the coolant may correspond to a
temperature of the lubricant. As used herein, "lubricant
temperature" may correspond to either, or both, of the lubricant
temperature directly and/or the coolant temperature. It is
understood that sensors 32, 34, 36 may include any type of sensor
such as resistive sensors, inductive sensors, capacitive sensors,
piezoelectric sensors, optical sensors, micro electro-mechanical
system sensors, or the like. Further, sensor system 30 may include
physical sensors and/or virtual sensors (e.g., sensors that
determine a value indirectly by controller 104 based on other
sensed values) and may include any number and/or combination of
sensors as necessary for sensing or measuring operating
conditions.
[0019] FIG. 2 illustrates a schematic view of the exemplary
lubricant dilution detection system 100 for operation and/or
control of at least portions of engine system 10. System 100 may
include inputs 102, controller 104, and outputs 106. Inputs 102 may
include, for example, lubricant pressure signal 110 from pressure
sensor 32, engine speed signal 112 from speed sensor 34, and
lubricant temperature signal 114 from temperature sensor 36.
Outputs 106 may include, for example, a lubricant dilution
indication signal 120. Controller 104 may also receive other inputs
(not shown) from other sensors or components of engine 12, such as,
for example, a key off signal, and/or signals from sensors
indicating one or more engine operating conditions. Controller 104
also includes a lubricant dilution detection module 108. Lubricant
dilution detection module 108 may receive inputs 102, implement a
method 300 for detecting dilution of lubricant in lubrication
system 14 and control outputs 106, as described with reference to
FIG. 3 below.
[0020] Controller 104 may embody a single microprocessor or
multiple microprocessors that may include means for detecting
dilution of lubricant in lubrication system 14. For example,
controller 104 may include a memory, a secondary storage device,
and a processor, such as a central processing unit or any other
means for accomplishing a task consistent with the present
disclosure. The memory or secondary storage device associated with
controller 104 may store data and/or software routines that may
assist controller 104 in performing its functions, such as the
functions of method 300 of FIG. 3. Further, the memory or secondary
storage device associated with controller 104 may also store data
received from the various inputs 102 associated with lubricant
dilution detection system 100. Numerous commercially available
microprocessors can be configured to perform the functions of
controller 104. It should be appreciated that controller 104 could
readily embody a general machine controller capable of controlling
numerous other machine functions. Further, controller 104, or
portions thereof, may be located remote from engine system 10.
Various other known circuits may be associated with controller 104,
including signal-conditioning circuitry, communication circuitry,
hydraulic or other actuation circuitry, and other appropriate
circuitry.
[0021] Controller 104 may also include stored values for use by
module 108. For example, the stored values may include shutdown
event thresholds and lubricant dilution thresholds. Shutdown event
thresholds may include one or more thresholds for various operating
conditions (e.g., engine speed, fuel pump flow rate, air intake,
etc.) of engine system 10 that indicate a shutdown event for engine
system 10, and thus indicate a shutdown event for lubrication
system 14. For example, the shutdown event thresholds may include
an engine speed threshold (e.g., 850 RPM). When one or more
operating conditions (e.g., engine speed) reduce below the
respective shutdown event threshold, controller 104 may determine
lubrication system 14 (e.g., engine 12) is shutting down. Shutdown
may be commanded by an operator of engine 12 (e.g., by a key off
event) and/or may be commanded by controller 104 (e.g., by one or
more operating conditions exceeding a threshold).
[0022] The lubricant dilution thresholds may include one or more
thresholds for indicating lubricant dilution for lubrication system
14. For example, the lubricant dilution thresholds may include one
or more lubricant dilution pressure thresholds. The one or more
lubricant dilution pressure thresholds may include a variable
threshold as a function of engine speed during a shutdown event (as
shown in FIGS. 4A and 4B by thresholds 410). For example, the one
or more lubricant dilution pressure thresholds may include
different pressure thresholds for different engine speeds during a
shutdown event provided in a map or lookup table. The information
used to derive the values of the map or lookup table may be
determined by empirical analysis. Such empirical data may be
obtained, for example, by operating a test engine system 10 under
predetermined conditions (e.g., under particular operating
conditions) during, for example, bench testing. For example, the
threshold values may be correlated to the values of the engine
operating conditions (e.g., engine speed). It is understood that
the map or lookup table may provide the values of the lubricant
dilution pressure threshold as a function of any type of input as
desired, such as other operating conditions (e.g., values
indicative of lubricant temperature).
[0023] The lubricant dilution thresholds may also include ranges
for various operating conditions during a shutdown event for
limiting the data points used in the measurements that are compared
to the thresholds. For example, the ranges may include an engine
speed range (e.g., 250-850 RPM), a lubricant pressure range (e.g.,
50-600 kPa), and/or a lubricant (e.g., or coolant) temperature
range (e.g., 65-105.degree. C., or 80-95.degree. C.). Thus, any
measured data points of lubricant pressure during which the
respective operating conditions (e.g., engine speed, lubricant
pressure, lubricant temperature) fall outside the respective ranges
may be disregarded, such that noise in the data may be filtered
out. Further, it is understood that the provided ranges are
exemplary only, and the engine speed range, lubricant pressure
range, and/or the lubricant temperature range may include any other
range as necessary for a respective application.
[0024] Lubricant dilution indication signal 120 may include control
of aspects of engine system 10. For example, lubricant dilution
indication signal 120 may include controller 104 outputting a
signal to display a value indicative of lubricant dilution in
lubrication system 14 on output indicator 16 (e.g., on a display).
Lubricant dilution indication signal 120 may also include
controller 104 outputting an alert, such as a light, an audible
alert, an alert on a display, or the like when there is lubricant
dilution. The lubricant dilution indication signal 120 may also
include mitigation or remediation recommendations. For example,
module 108 may recommend service intervals, lubrication system
tests, fuel system tests, and/or any other maintenance techniques
for locating, mitigating, and/or remediating the cause of the
lubricant dilution. Lubricant dilution indication signal 120 may
also include controller 104 adjusting the engine system 10. For
example, controller 104 may derate or shut down engine system 10 or
portions thereof.
INDUSTRIAL APPLICABILITY
[0025] The disclosed aspects of the lubricant dilution detection
system 100 of the present disclosure may be used in any lubrication
system 14 that supplies pressurized lubricant.
[0026] Referring to FIG. 1, during the operation of engine system
10, engine 12 may drive pump 20 such that pump 20 may draw
lubricant from lubricant supply 18. Pump 20 may thus provide
pressurized lubricant out of pump 20 to components of engine 12
through supply line 24 such that the components of engine 12 are
lubricated. For example, as engine speed increases, pump 20 speed
may increase such that lubricant pressure increases. During
operation of engine system 10, the pressurized lubricant may be
regulated at a predetermined pressure in supply line 24 by valve 26
at certain engine speeds, as detailed above. For example, when the
engine speed increases over a predetermined value, valve 26 may
open proportionally such that the lubricant pressure does not
exceed a predetermined pressure value (e.g., 600 kPa). In some
instances, the lubricant may become diluted such that the viscosity
of the lubricant decreases due to various causes, as detailed
above. For example, coolant from a lubricant cooler of the
lubrication system 14 and/or fuel (e.g., diesel) from one or more
fuel injectors of the fuel system of the engine 12 may leak into
the lubricant supply 18. The coolant and/or the fuel may have a
lower viscosity than the lubricant such that the viscosity of the
lubricant-coolant/fuel mixture is lower than the viscosity of the
lubricant itself. When the lubricant is diluted, the components of
the engine 12 may become damaged due the reduced lubrication
ability of the lubricant. Further, as valve 26 regulates the
lubricant pressure at relatively higher engine speeds, it may be
difficult to detect lubricant dilution when valve 26 is open. For
example, the lubricant pressure may build to the predetermined
value to open valve 26 even if the lubricant is diluted. Therefore,
lubricant dilution may not be adequately detected during relatively
higher engine speeds when valve 26 is open. Further, in some types
of engine systems, valve 26 may not close while the engine is
operating (e.g., during an idle condition). Thus, as detailed below
with reference to FIG. 3, lubricant dilution detection system 100
may detect lubricant dilution during shutdown events of engine
system 10 when valve 26 is closed (e.g., at engine speeds less than
850 RPM).
[0027] FIG. 3 illustrates a flowchart depicting an exemplary method
300 for detecting lubricant dilution for lubrication system 14. In
step 305, module 108 may detect a shutdown event of lubrication
system 14 (e.g., shutdown of engine system 10). For example, module
108 may receive a shutdown signal (e.g., key off or commanded by
controller 104) and/or may otherwise measure engine speed and
determine that the engine speed is decreasing below the
predetermined shutdown threshold. As detailed above, module 108 may
utilize other operating condition parameters and respective
shutdown event thresholds (e.g., engine speed, fuel pump flow rate,
air intake, etc.). In accordance with a determination that a
respective operating condition decreases below the respective
shutdown event threshold, module 108 may determine a shutdown event
of lubrication system 14. It is understood that module 108 may
detect a shutdown event of lubrication system 14 by any other
method known in the art.
[0028] In step 310, when module 108 has detected a shutdown event
of lubrication system 14, module 108 may measure lubricant pressure
of lubrication system 14 during the shutdown event. For example,
controller 104 may receive the lubricant pressure signal 110 and
determine, or otherwise derive, the lubricant pressure of
lubrication system 14. Module 108 may also determine a rate of
lubricant pressure change over time based on the lubricant pressure
signal 110. Further, eventually the lubricant pressure will
approach and decrease to zero when lubrication system 14 is
completely shut down (e.g., when the shutdown event is complete).
Therefore, module 108 may limit the measurement window for method
300 when engine speed is in the engine speed range (e.g., between
250-850 RPM), as detailed above.
[0029] In step 315, module 108 may determine whether the measured
lubricant pressure is less than a threshold (e.g., the lubricant
dilution threshold based on operating conditions, as detailed
above). For example, when there is no dilution, or negligible
dilution, and the lubrication system 14 shuts down, the lubricant
pressure will be above the respective lubricant dilution threshold
for a respective operating condition (e.g., engine speed). Thus,
when the measured lubricant pressure is greater than or equal to
the threshold (Step 315: NO), module 108 may repeat the method 300
and continue to detect shutdown events (step 305).
[0030] When the lubricant is diluted, the lubricant pressure may
decrease below the respective lubricant dilution threshold for a
respective operating condition (e.g., engine speed) during the
shutdown. Thus, in step 320, in accordance with a determination
that the measured lubricant pressure is less than the threshold
(Step 315: YES), module 108 may output an indication of lubricant
dilution. For example, module 108 may display the indication of the
lubricant dilution on output indicator 16 (e.g., on a display
and/or as a notification, such as a light, an audible alert, an
alert on a display, etc.). Module 108 may then repeat the method
300 and continue to detect shutdown events (step 305). Further,
module 108 may store the indication of lubricant dilution (e.g., as
a flag), such that module 108 may indicate lubricant dilution when
lubrication system 14 is started up again. Module 108 may also
generate recommendations for mitigating the lubricant dilution and
output the recommendations (e.g., via output indicator 16).
[0031] In some embodiments, module 108 may store values or
instances of the measured lubricant pressure during a plurality of
shutdown events. For example, module 108 may detect several
different shutdown events and store values of the measured
lubricant pressure. Referring to FIGS. 4A and 4B, module 108 may
generate a plot 400a, 400b of the measured lubricant pressure for
the different shutdown events over time. For example, FIG. 4A
provides a plot 400a of lubricant pressure versus engine speed
during shutdown according to a first embodiment. Similarly, FIG. 4B
provides a plot 400b of lubricant pressure versus engine speed
during shutdown according to a second embodiment. Plots 400a, 400b
may include a graphical representation of various data points 405a,
405b of the measured lubricant pressure for various engine speeds.
Further, the dashed line indicates the lubricant dilution
thresholds 410 for the various engine speeds. As shown in FIG. 4A,
the lubricant dilution thresholds 410 may be substantially linear
as engine speed decreases during a shutdown event (e.g., engine
speed less than 850 RPM, as indicated by the vertical dashed line
in FIG. 4A). However, in embodiments where pump 20 is driven by
engine 12 (e.g., the crankshaft), there is a second order
relationship between lubricant pressure out of pump 20 and engine
speed. For example, a delay may exist between engine speed
decreasing and pump 20 speed decreasing, thus causing a delay in
lubricant pressure decreasing as engine speed decreases.
Accordingly, the relationship between lubricant pressure and engine
speed may not be exactly linear. Thus, as shown in FIG. 4B, the
lubricant dilution thresholds 410 are not exactly linear as engine
speed decreases. For example, the thresholds 410 may be exponential
or may include another type of relationship between lubricant
pressure and engine speed. Thus, lubricant dilution may exist when
one or more data points 405b fall below the respective lubricant
dilution threshold 410 for a respective engine speed during the
shutdown. As detailed above, it is understood that plots 400a, 400b
may include lubricant pressure versus other operating conditions
other than engine speed, such as, for example, lubricant
temperature or any other operating condition.
[0032] Further, to reduce or eliminate false triggers of lubricant
dilution detection, module 108 may include one or more
predetermined ranges for various operating conditions. For example,
module 108 may consider data points 405a, 405b of the measured
lubricant pressure that are measured when a value indicative of
engine speed is between 250-850 RPM, a value indicative of
lubricant temperature (e.g., as measured from lubricant temperature
signal 114) is between 65-105.degree. C. (or 80-95.degree. C.),
and/or a value indicative of lubricant pressure is between 50-600
kPa. Thus, module 108 may disregard or otherwise eliminate data
points of the measured lubricant pressure when the respective
operating conditions are outside the respective ranges. To further
reduce or eliminate false triggers of lubricant dilution detection,
module 108 may also include debounce conditions. For example, the
debounce conditions may include predetermined thresholds for an
amount of time (e.g., 3 seconds) the measured lubricant pressure is
less than the lubricant dilution thresholds. Similarly, module 108
may also include an amount of data points 405b that required to be
less than the lubricant dilution thresholds as a function of the
total amount of data points 405a, 405b. For example, if 3 out of 15
data points fall below the lubricant dilution thresholds, module
108 may determine lubricant dilution.
[0033] Lubricant dilution detection system 100 may provide an
indication of lubricant dilution in lubrication system 14. For
example, lubricant dilution detection system 100 may detect
lubricant dilution due to, for example, fuel leaks in a fuel system
of engine 12, coolant leaks from a lubricant cooler, age of the
lubricant, and/or any other causes of dilution. Further, by
detecting lubricant dilution during shutdown events, lubricant
dilution detection system 100 may ensure that valve 26 is closed
such that system 100 may more adequately detect lubricant dilution.
Accordingly, lubricant dilution detection system 100 may more
accurately or adequately detect lubricant dilution in lubrication
system 14 and proactively alert a user (e.g., operator, technician,
etc.) so that the user may repair and/or replace the respective
component to mitigate the lubrication dilution.
[0034] It will be apparent to those skilled in the art that various
modifications and variations can be made to the disclosed system
without departing from the scope of the disclosure. Other
embodiments of the system will be apparent to those skilled in the
art from consideration of the specification and practice of the
system disclosed herein. It is intended that the specification and
examples be considered as exemplary only, with a true scope of the
disclosure being indicated by the following claims and their
equivalents.
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