U.S. patent application number 11/148651 was filed with the patent office on 2005-10-13 for wireless mems sensing device.
This patent application is currently assigned to PTI TECHNOLOGIES, INC.. Invention is credited to Ellis, Rowland, Moscaritolo, Daniel.
Application Number | 20050228609 11/148651 |
Document ID | / |
Family ID | 32107246 |
Filed Date | 2005-10-13 |
United States Patent
Application |
20050228609 |
Kind Code |
A1 |
Moscaritolo, Daniel ; et
al. |
October 13, 2005 |
Wireless MEMS sensing device
Abstract
A sensor component that may be used in conjunction with a filter
module may include a plurality of sensor packages. The latter, in
turn, may incorporate one or more micro-electromechanical systems
(MEMS) sensors to measure various characteristics of fluid flow and
filtration. A single sensor component may be adapted to measure the
pressure, temperature, flow rate, differential pressure,
conductivity, viscosity, pH level, etc. of the fluid at an upstream
and a downstream location. Sensor measurements may be obtained
continuously in order to monitor and indicate fluid conditions,
including the use of a warning mechanism to indicate an
out-of-range condition when the measurements fall outside of
pre-set limits. Depending on the application and the fluid being
filtered, data, including measurement data, may be transmitted
through electrical connections or wirelessly. In wireless
configurations, a sleep-mode may be included to maximize the life
of local power supplies.
Inventors: |
Moscaritolo, Daniel;
(Newbury Park, CA) ; Ellis, Rowland; (Ventura,
CA) |
Correspondence
Address: |
PILLSBURY WINTHROP SHAW PITTMAN LLP
725 S. FIGUEROA STREET
SUITE 2800
LOS ANGELES
CA
90017
US
|
Assignee: |
PTI TECHNOLOGIES, INC.
Oxnard
CA
93030-7983
|
Family ID: |
32107246 |
Appl. No.: |
11/148651 |
Filed: |
June 9, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11148651 |
Jun 9, 2005 |
|
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10281834 |
Oct 28, 2002 |
|
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6936160 |
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Current U.S.
Class: |
702/127 |
Current CPC
Class: |
B01D 29/606 20130101;
B01D 29/608 20130101; B01D 35/143 20130101; B01D 29/603
20130101 |
Class at
Publication: |
702/127 |
International
Class: |
G06F 015/00; G06M
011/04; G01D 001/00 |
Claims
What is claimed is:
1. A filtration monitoring system comprising: a filter module
including a filter element having an end cap at an end thereof,
said filter element receiving a fluid in an unfiltered state at an
inlet side and producing said fluid in a filtered state at an
outlet side; a single-body sensor component coupled to said end
cap, said sensor component having a single housing and at least a
first sensor package and a second sensor package disposed within
said housing, each said sensor package including a
micro-electromechanical systems (MEMS) sensor, and each said sensor
package being configured to measure at least one member selected
from the group consisting of temperature, pressure, and flow rate,
wherein said filter element, said end cap, and said sensor
component are adapted to be housed within a casing; a transmitter
coupled to said sensor component, said transmitter being configured
to wirelessly transmit measurement data to a remote signal
receiver; and a data-processing device configured to receive data
from said signal receiver.
2. The monitoring system of claim 1, wherein said first sensor
package is adapted to be in communication with said unfiltered
fluid upstream of said filter element and said second sensor
package is adapted to be in communication with said filtered fluid
downstream of said filter element.
3. The monitoring system of claim 2, wherein a differential
pressure is calculated based on a pressure measurement taken by
said first sensor package for the unfiltered fluid and a pressure
measurement taken by said second sensor package for the filtered
fluid.
4. The monitoring system of claim 3, wherein the data-processing
device is configured to calculate said differential pressure.
5. The monitoring system of claim 1, wherein each said sensor
package includes a MEMS pressure sensor.
6. The monitoring system of claim 1, wherein said sensor component
further includes a processor.
7. The monitoring system of claim 6, wherein each of said first and
second sensor packages is configured to communicate its respective
measurements to said processor.
8. The monitoring system of claim 1, wherein said measurement data
are transmitted to said signal receiver as RF signals.
9. The monitoring system of claim 1, wherein said casing includes
top and bottom ends and said signal receiver is coupled to the
bottom end of said casing.
10. The monitoring system of claim 9, wherein the signal receiver
is threadably coupled to said bottom end.
11. The monitoring system of claim 1, said signal receiver further
including a warning mechanism configured to indicate an
out-of-range condition of said fluid.
12. The monitoring system of claim 11, wherein said condition is
determined based on measurement of one or more of said fluid's
pressure, temperature, flow rate, and differential pressure, and
said warning mechanism includes a visual indicator.
13. The monitoring system of claim 1, further including a
sleep-mode feature, wherein said first and second sensor packages
and said signal receiver are configured to remain in an unactuated
state in the absence of fluid flow, said first and second sensor
packages becoming actuated once fluid flow is initiated, and said
signal receiver becoming actuated upon receipt of said measurement
data.
14. The monitoring system of claim 1, wherein said measurement data
are transmitted to said signal receiver as ultra-sonic signals.
15. The monitoring system of claim 1, wherein said measurement data
are transmitted to said receiver in real time.
16. The monitoring system of claim 1, said sensor component further
comprising a third sensor package having a MEMS sensor, wherein
said third sensor package is in contact with the unfiltered fluid
and is configured to measure at least one member selected from the
group consisting of a conductivity, a pH level, and a viscosity of
said unfiltered fluid.
17. The monitoring system of claim 16, wherein said sensor
component further includes a processor and said third sensor
package is configured to communicate its measurements to said
processor.
18. The monitoring system of claim 1, wherein the data-processing
device is further configured to determine the status of the filter
element.
19. The monitoring system of claim 18, wherein said status includes
the remaining life of said filter element.
20. The monitoring system of claim 1, wherein the data-processing
device receives said data from said signal receiver in real
time.
21. The monitoring system of claim 1, wherein at least one of the
sensor packages includes redundant MEMS sensors.
22. The monitoring system of claim 1, wherein said sensor component
includes a redundant sensor package.
23. A filtration monitoring system comprising: a filter module
including a filter element having an end cap at an end thereof,
said filter element receiving a fluid in an unfiltered state
upstream of the filter element and producing said fluid in a
filtered state downstream of the filter element; a single-body
sensor component coupled to said end cap through a sensor port
defined therethrough, said sensor component having a single housing
and a first micro-electromechanical systems (MEMS) pressure sensor
and a second MEMS pressure sensor disposed within said housing,
wherein said first pressure sensor is adapted to be in
communication with said unfiltered fluid and said second pressure
sensor is adapted to be in communication with said filtered fluid
so as to enable calculation of a differential pressure based on
respective measurements of said first and second pressure sensors;
a casing having top and bottom ends and being configured to house
therein said filter element, said end cap, and said sensor
component; a signal receiver coupled to said bottom end of said
casing; a transmitter coupled to said sensor component, wherein
said transmitter is configured to wirelessly transmit measurement
data from said first and second pressure sensors to said signal
receiver; and a data-processing device configured to receive data
from said signal receiver.
24. The monitoring system of claim 23, wherein said measurement
data are transmitted to said signal receiver in real time.
25. The monitoring system of claim 23, further including a
retaining brace configured to be removably coupled to said end cap,
said brace retaining the sensor component within said sensor
port.
26. The monitoring system of claim 25, wherein said brace is
coupled to said end cap with a connection means.
27. The monitoring system of claim 25, wherein the sensor component
is configured to be retained within said sensor port by a plurality
of overlapping braces.
28. The monitoring system of claim 23, said sensor-component
housing being further configured to receive a power supply and
electronics thereon.
29. The monitoring system of claim 28, wherein said
sensor-component housing further includes a sealing member around
the periphery thereof, said sealing member being configured to
provide a fluid-tight interface between said sensor-component
housing and said sensor port.
30. The monitoring system of claim 28, wherein said power supply
includes a battery.
31. The monitoring system of claim 30, wherein said battery is
rechargeable.
32. The monitoring system of claim 23, wherein said signal receiver
includes a power supply and electronics, configured to be locked in
place within a receiver housing.
33. The monitoring system of claim 32, wherein said power supply
includes a rechargeable battery.
34. The monitoring system of claim 23, further including a
sleep-mode feature, wherein said first and second pressure sensors
and said signal receiver are configured to remain in an unactuated
state in the absence of fluid flow, said first and second pressure
sensors becoming actuated once fluid flow is initiated, and said
signal receiver becoming actuated upon receipt of said measurement
data.
35. The monitoring system of claim 23, wherein the data-processing
device is configured to calculate said differential pressure.
36. The monitoring system of claim 23, wherein the data-processing
device is further configured to determine the status of the filter
element.
37. The monitoring system of claim 36, wherein said status includes
the remaining life of said filter element.
38. The monitoring system of claim 23, wherein the data-processing
device receives said data from said signal receiver in real
time.
39. A filtration monitoring system comprising: a filter module
including a filter element having an end cap at an end thereof,
said filter element receiving a fluid in an unfiltered state at an
inlet side upstream of the filter element and producing said fluid
in a filtered state at an outlet side downstream of the filter
element; a single-body sensor component coupled to said end cap
through a sensor port defined therethrough, said sensor component
having a single housing, a first sensor package that is adapted to
be in communication with said unfiltered fluid and a second sensor
package that is adapted to be in communication with said filtered
fluid, said first sensor package including a first
micro-electromechanical systems (MEMS) sensor, said second sensor
package including a second MEMS sensor, and both of the first and
second sensor packages being disposed within said single housing; a
casing having top and bottom ends and being configured to house
therein said filter element, end cap, and sensor component; a
signal receiver coupled to said bottom end of said casing; a
transmitter coupled to said sensor component, said transmitter
being configured to wirelessly transmit measurement data from said
first and second MEMS sensors to said signal receiver; a
data-processing device configured to receive data from said signal
receiver; and a sleep-mode feature, wherein said first and second
MEMS sensors and said signal receiver are configured to remain in
an unactuated state in the absence of fluid flow, said first and
second MEMS sensors becoming actuated once fluid flow is initiated,
and said signal receiver becoming actuated upon receipt of said
measurement data.
40. The monitoring system of claim 39, wherein the sensor component
further includes a processor.
41. The monitoring system of claim 39, wherein said data-processing
device is configured to determine the status of the filter element,
calculate a pressure differential across the filter element, or
both.
42. The monitoring system of claim 39, wherein the data-processing
device receives said data from said signal receiver in real time.
Description
RELATED APPLICATION DATA
[0001] This is a continuation of application Ser. No. 10/281,834,
filed Oct. 28, 2002, now U.S. Pat. No. ______, and is related to
application Ser. No. 11/006,137, filed Dec. 7, 2004, which is a
continuation of application Ser. No. 10/281,835, filed Oct. 28,
2002, now U.S. Pat. No. 6,852,216; to application Ser. No.
11/028,978, filed Jan. 4, 2005, which is a continuation of
application Ser. No. 10/818,248, filed Apr. 5, 2004, now U.S. Pat.
No. 6,855,249, which is a continuation of Ser. No. 10/259,905,
filed Sep. 27, 2002, now U.S. Pat. No. 6,736,980, which is a
division of application Ser. No. 09/721,499, filed Nov. 22, 2000,
now U.S. Pat. No. 6,471,853; and to application Ser. No.
10/903,727, filed Jul. 30, 2004, now U.S. Pat. No. ______, which is
a continuation of application Ser. No. 10/281,692, filed Oct. 28,
2002, now U.S. Pat. No. 6,823,718.
FIELD OF INVENTION
[0002] The present invention is directed to filtration systems
incorporating micro-electromechanical systems (MEMS) to provide
flow and filtration characteristic data.
BACKGROUND
[0003] Filter modules have been used in a variety of applications
and fluidic environments. When in service, it is often desirable to
sense and measure various fluid flow and filter performance
characteristics in order to determine whether a filter element
within the filter module is performing within application
specifications, and whether a filter element must be replaced or
reconditioned before continuing operation.
[0004] In typical filter modules, a filter element is encased
within a filter body, or casing (e.g., a filter bowl), and between
inlet and outlet end caps. A filter manifold(s) may be attached to
the filter body to feed unfiltered medium to the upstream side of
the filter element (e.g., where the filter element is cylindrical,
the outside of the filter element). As the medium passes to the
downstream side of the filter element through the membrane
material, contaminants are removed from the medium. Filtered medium
is then collected from the downstream side of the filter element
(e.g., where the filter element is cylindrical, the inside of the
filter element).
[0005] During the filter element's service life, an increasing
amount of removed contaminant will collect on one side of the
filter element in a phenomenon known as fouling. Fouling causes the
pressure difference between the upstream and downstream sides of
the filter element to increase, and thereby lowers the filtration
efficiency of the filter element. If the differential pressure
exceeds a certain value that is dependent upon the filter element
material and design, the filter element may be damaged.
Additionally, at high differential pressures, particle breakthrough
(i.e., contaminant particles passing through the pores in the
filter element) may occur.
[0006] In prior modules, the filter head may have contained
conventional pressure transducers, magnetic type differential
pressure sensors, virtual pressure switches, and temperature
detectors to measure characteristics of fluid flow and filter
performance. These components are used to sense the differential
pressure across the filter element to determine whether the filter
element is sufficiently clogged with contaminant removed from the
fluid flow to require replacement. These pressure sensors are
generally binary in nature, i.e., they either indicate that the
filter element needs to be replaced (e.g., by causing a part to pop
up out of the exterior of the filter head) or that it is still
useable.
[0007] Typically, traditional differential pressure indicators
(e.g., spring and piston designs) contain a multiplicity of
discrete, macro-scale, mechanical parts and/or components, which
makes them more prone to failure. As an example, a thermal lockout
mechanism is typically used to prevent false indications during
cold-start conditions. In existing designs, the thermal lockout
mechanism uses the thermal expansion qualities of BI-metal strips
to keep the differential pressure indicator from actuating until a
pre-set temperature is reached. However, false indications are
received when mechanical failures occur within the lockout
mechanism.
[0008] The use of the pressure-sensing components used in
traditional filter modules is also often a significant design
constraint in weight- and size-sensitive applications, e.g.,
aircraft filtration systems. Moreover, traditional filter modules
offer no real-time means for predicting when a filter element will
need to be replaced. In addition, traditional filter modules
disturb or alter fluid flow by requiring that sensing components be
inserted into the stream of flow, creating turbulence. Also, prior
sensors are designed to indicate an out-of-range condition when the
value of a measured property falls outside of pre-set limits. As
such, continuous measurement and real-time monitoring and
indication may not be available with such designs.
[0009] Moreover, traditionally, separate devices have typically
been used to measure different properties (e.g., temperature and
pressure), thus increasing the size and cost of the overall system.
Similarly, at present, filter or fluid power manifolds that have
separate upstream circuits but share a common downstream passage
require the use of separate devices to measure, e.g., differential
pressure, across each filter element (or any device or component
that provides a measurable pressure drop). This also holds true for
filter or fluid power manifolds that have separate downstream
circuits, but share a common upstream passage. As before, the use
of separate individual devices is generally disadvantageous as it
leads to increased cost, weight, design envelope size, and reduced
reliability.
[0010] In recent years, attempts have been made to overcome the
above-mentioned shortcomings by using Micro-Electro-Mechanical
Systems (MEMS) devices in conjunction with filter modules. MEMS
devices comprise semiconductor chips which include microfabricated
mechanical systems on the chip. More generally, MEMS are directed
to the integration of mechanical elements, sensors, actuators, and
electronics on a common substrate through the utilization of
microfabrication technology. While the electronics are fabricated
using integrated circuit (IC) process sequences, the
micromechanical components are fabricated using compatible
micromachining processes that selectively etch away parts of a
silicon wafer, e.g., or add new structural layers (e.g., by
deposition), to form the mechanical and electromechanical devices.
In this way, MEMS represents a complete systems-on-a-chip, free of
discrete, macro-scale, moving mechanical parts. In short, in MEMS
devices, the microelectronic integrated circuits provide the
decision-making capability which, when combined with MEMS sensors,
actuators, etc., allow Microsystems to sense, provide feedback
to/from, and control the environment.
[0011] Thus, commonly-assigned U.S. application Ser. No.
09/721,499, filed Nov. 22, 2000, now U.S. Pat. No. 6,471,853, is
directed to a filter module that incorporates MEMS sensors to
measure various characteristics of fluid flow and filtration,
including the temperature, flow rate, pressure, etc. of the fluid.
One or more MEMS sensors may be incorporated into a sensor package
which, in turn, is included in a sensor component. The latter,
which typically may include a processor, conductor pins, etc. for
data communication, is coupled to a sensor port of a manifold in
such a way as to allow contact between the fluid and at least one
surface of the sensor(s).
[0012] As shown in FIGS. 1A and 1B, a filter module containing a
MEMS sensor component of the type described in the above-mentioned
patent application may include a filter body (e.g., a filter bowl)
1, a filter element 2, and a filter manifold 3. The filter manifold
3 may have one or more sensor ports 4 in which one or more MEMS
sensor components 5 may be mounted. The filter manifold 3 may have
one or more inlet fluid flow cavities 6 and one or more outlet
fluid flow cavities 7. The sensor ports 4 may extend through the
housing 8 of the filter manifold 3. Seals may be used to ensure
that the interface between each sensor port 4 and the corresponding
sensor component 5 is made fluid-tight.
[0013] The filter element 2 may have an end cap 9 attached to one
end (the dead end). In general, the shape and location of the inlet
fluid flow cavity 6 and the outlet fluid flow cavity 7 may depend
upon a number of factors, including the desired flow
characteristics of the unfiltered or filtered fluid, the size and
shape of the filter element 2 and filter body 1, the fluid being
filtered, and the like. Each sensor component 5 includes a sensor
package 10 which contains one or more MEMS sensors. As shown in
FIG. 1B, the sensor ports 4 and the sensor components 5 are
configured such that, when in place, each sensor package 10 is
flush with the stream of fluid flow (e.g., flush with the inner
surface of inlet cavity 6 and outlet cavity 7).
[0014] In order to measure the differential pressure between two
locations of fluid flow (e.g., across a filter element 2) using
MEMS sensor components of the type described above, at least two
such sensor components must be used. More specifically, a first
MEMS sensor component 5 having at least one pressure sensor is
deployed at an upstream location, e.g., within a port 4 in an inlet
cavity 6, and a second MEMS sensor component 5 having at least one
pressure sensor is deployed at a downstream location, e.g., within
a port 4 in an outlet cavity 7. Respective pressure readings from
the first and second sensor components are communicated to a
processor or similar device through electrical conductors, and a
differential pressure across the membrane of the filter element 2
is calculated based on the difference between the first and second
sensor component readings.
[0015] MEMS sensor components of the type described above have thus
improved upon conventional modules and sensors by eliminating
macro-scale mechanical parts, addressing weight and size concerns,
allowing real-time monitoring, and providing a sensor package that
can be placed flush with the stream of flow, thus avoiding
interference with fluid flow. Nevertheless, in light of the high
cost of retrofittable sensors (e.g., differential pressure sensors)
and the difficulties associated with wiring such sensors to a
"communications bus", there is a need for low-cost, lower-weight,
reliable, non-mechanical sensing devices that may be retrofittable,
capable of integrating one or more differential pressure sensors,
and capable of wirelessly communicating sensing- and
measurement-related data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIGS. 1A and 1B depict a typical filter module having a
manifold which is configured to receive one or more sensor
components within sensor ports thereof;
[0017] FIG. 2 shows a sensor component according to an embodiment
of the present invention;
[0018] FIG. 3 is a bottom view of the embodiment shown in FIG.
2;
[0019] FIG. 4 shows a cross-sectional view through segment A-A of
the embodiment shown in FIG. 3;
[0020] FIG. 5 shows a top view of the embodiment shown in FIG.
2;
[0021] FIG. 6 shows a side view of the embodiment shown in FIG.
2;
[0022] FIG. 7 is an illustration of an alternative embodiment of
the present invention;
[0023] FIG. 8 is a bottom view of the embodiment shown in FIG.
7;
[0024] FIG. 9 shows a cross-sectional view through line A-A of the
embodiment shown in FIG. 8;
[0025] FIG. 10 shows a cross-sectional view through line B-B of the
embodiment shown in FIG. 8;
[0026] FIG. 11 shows an attachment configuration for use with an
embodiment of the present invention;
[0027] FIG. 12 shows an alternative embodiment of the present
invention;
[0028] FIG. 13 depicts a schematic of a hydraulic system using a
sensor component according to an embodiment of the present
invention;
[0029] FIG. 14 shows an alternative embodiment of the present
invention;
[0030] FIG. 15 shows a top view of the embodiment depicted in FIG.
14;
[0031] FIG. 16 shows a cross-sectional view through segment A-A of
the embodiment shown in FIG. 15;
[0032] FIG. 17 is an illustration of an alternative embodiment of
the present invention;
[0033] FIG. 18 shows an embodiment of a filter element bowl and
signal receiver of the embodiment shown in FIG. 17;
[0034] FIG. 19 is an exploded view of an end cap of the embodiment
shown in FIG. 17; and
[0035] FIG. 20 is an illustration of a signal receiver assembly of
the embodiment shown in FIG. 18.
DETAILED DESCRIPTION
[0036] Embodiments of the present invention are directed to sensor
components in which various MEMS sensors for measuring pressure,
differential pressure, flow rate, temperature, pH level, viscosity,
and/or moisture content of the fluid flow may be used. Multiple
MEMS sensors may be arranged on a single chip to form a sensor
package, and multiple sensor packages may be included in a single,
unitary sensor component. The MEMS sensors may output real-time
measurements or related data, thus allowing real time continuous
monitoring of the fluid system. The measurements or data may be
interpreted to predict when failure of the filter element will
occur or to determine whether replacement of the filter element is
necessary. In particular embodiments, MEMS sensor data may be used
to detect the occurrence of undesirable events such as particle
breakthrough or cavitation.
[0037] In addition to allowing real time continuous monitoring (as
opposed to merely providing an indication at pre-set values), the
present invention improves reliability by reducing the number of
macro-scale mechanical components and/or moving parts that are
typically used in traditional systems, as well as by allowing
redundancy of sensor packages and/or of sensors within a given
sensor package. Moreover, by including multiple MEMS sensors on a
sensor package, the present invention eliminates the need for
separate devices to measure temperature, pressure, differential
pressure, etc. This, in turn, reduces costs, as well as system
weight and envelope size.
[0038] In some embodiments, a single sensor component may contain
multiple pressure sensors which are configured in such a way as to
allow determination of a differential pressure without the need to
include an additional sensor component. Thus, the inclusion of
multiple sensor packages in a single sensor component allows
installation, or retro-fitting, in applications where only one port
is available and traditional devices and methods would require two
separate sensor ports and assemblies (e.g., measuring differential
pressure with a single sensor component placed into a single port,
as opposed to placing two separate sensor assemblies into two
separate ports).
[0039] Embodiments of the present invention are also directed to
single-body sensor components (e.g., single-body differential
pressure devices) that may be used in systems having multiple
separate upstream circuits that share a common downstream passage
or, vice versa, where multiple separate downstream circuits share a
common upstream passage. In one embodiment, the present invention
also provides a MEMS sensor component having a wireless
data-communication capability.
[0040] FIG. 2 shows a sensor component 500 according to an
embodiment of the present invention. As shown in FIGS. 3-6, the
sensor component 500 may generally have a cylindrical
configuration. In a preferred embodiment, the sensor component 500
includes at least a first MEMS sensor package 522 and a second MEMS
sensor package 524, wherein each sensor package contains one or
more MEMS sensors, including sensors for measuring pressure,
temperature, differential pressure, and flow rate. In the
embodiment of FIG. 4, a bottom view of which is shown in FIG. 3, a
third sensor package 530 may be included, with MEMS sensors for
measuring viscosity, pH level/acidity, conductivity, free water
content, lubricity, oxidation reduction potential (ORP), etc. of a
given fluid.
[0041] In a preferred embodiment, at least one of the sensor
packages (e.g., the first sensor package 522) is exposed directly
to the upstream fluid, i.e., the fluid that is transmitted to the
inlet side of the filter element. Thus, as shown in FIG. 4, when
placed into a sensor port 547, a front face of the sensor package
is flush with the interior surface 517 of the filter manifold 516
(or of the fluid flow cavity, or other structure housing the sensor
component) in such a way as to be in contact with the fluid as it
flows by.
[0042] A second sensor package, however, might not be flush with
the stream of fluid flow. Rather, as depicted in FIG. 4, the second
sensor package 524, e.g., is isolated from the upstream fluid via a
plug 528 that is inserted at one end of the sensor component 500.
The second sensor package 524 is arranged such that it can measure
properties of the downstream fluid (e.g., the fluid that is
transmitted from the outlet side of the filter element) through an
aperture 542 (see FIG. 6) within the casing 515 of the sensor
component 500, and a channel 526 (see FIG. 4) that provides an
opening through the manifold 516. Thus, downstream fluid
measurement may be obtained by porting the downstream fluid to the
second sensor package 524. In an alternative embodiment, downstream
fluid conditions may be monitored without direct contact between
the fluid and the sensor package 524 by using, e.g., a
pitot-tube-type arrangement in conjunction with channel 526 and
aperture 542. In addition, an isolation seal 520 may be used to
isolate upstream and downstream pressures.
[0043] In embodiments of the present invention, data collected
using the multiplicity of sensors and/or sensor packages may be
processed and/or transmitted through the use of electrical
conductors and data-processing devices. For example, the embodiment
shown in FIG. 4 includes electrical conductors 518 for
communication of measurement data to a processor 512. The processor
512, in turn, may be connected to conductive pins 550 of an
electrical connector signal interface 510 in such a way as to allow
transmission of data from the sensor component 500 (to, e.g., a
separate data processing device). In other embodiments discussed
below, data transmission may be achieved wirelessly.
[0044] Advantageously, using the data
collection/transmission/processing capabilities described herein,
embodiments of the present invention allow for measurement of
differential pressure and similar parameters using a single MEMS
sensor component by including multiple sensor packages within the
same sensor component. This is especially desirable in applications
(e.g., retrofitting/updating older systems) where only one
sensor-component port, rather than two, is available for measuring
differential pressure and other such parameters. In addition, in
contrast to existing designs, where an indication is provided only
when pre-set parameter values have been reached, embodiments of the
present invention allow continuous real-time monitoring of the
fluid system.
[0045] Moreover, embodiments of the present invention achieve
improved reliability by allowing the use of redundant sensor
packages, as well as redundant sensors in each sensor package.
Also, the sensors may be temperature compensated to ensure accuracy
over the entire mission range. In addition, given their relatively
small mass, the MEMS sensor packages are inherently tolerant of
extreme vibrational environments.
[0046] In an alternative embodiment, shown in FIGS. 7-10, the
sensor component 500 comprises a warning mechanism 610 at an end
opposite the sensor packages 522,524. The warning mechanism 610 may
include a visual warning light, an audible alarm, etc. configured
to indicate an out-of-range condition of the fluid. Typically, the
warning mechanism 610 will be battery operated, utilizing a
replaceable battery 630 as depicted in FIG. 9. In addition, the
sensor component 500 may include a transparent dust cover 620 to
protect the warning mechanism 610, especially when the warning
mechanism 610 is a visual warning light.
[0047] The embodiment shown in FIGS. 7-10 includes the first and
second sensor packages, 522, 524, as well as a third sensor package
530. More specifically, FIG. 10 shows a cross-sectional view of the
sensor component through line A-A of FIG. 8, and FIG. 10 shows a
cross-sectional view of the sensor component through line B-B of
FIG. 8. In FIG. 9, the second sensor package 524 is shown with a
connection to the processor 512 via electrical conductors 518. FIG.
10, on the other hand, depicts the first sensor package 522, and
the third sensor package 530.
[0048] As shown in FIG. 4, the sensor component 500 may be held in
place within the sensor port 517 by a housing seal 514.
Alternatively, the various embodiments of the sensor component 500
may be threaded, or may include a flange 680 that is perpendicular
to the longitudinal axis of the sensor component 500 and which
protrudes from the periphery of the sensor component (see FIG. 11).
The flange 680 is configured to be secured to the filter manifold
516 with bolts or other similar means, thus holding the sensor
component in place.
[0049] FIG. 12 shows yet another alternative embodiment of the
sensor component 500. Here, a warning mechanism is contained within
the casing 515 of the sensor component 500. The casing 515, in
turn, includes circumferential holes 693 through the periphery
thereof, such that a visual warning light can be seen through the
holes 693. As such, in this embodiment, a visual out-of-range
indication is provided through the holes 693 rather than through a
transparent cover (e.g., transparent dust cover 620) placed at one
end of the sensor component 500.
[0050] FIGS. 13-16 show an alternative embodiment of the present
invention for applications requiring data collection from more than
two points within a given system. More specifically, FIG. 13 is a
schematic diagram of a hydraulic system wherein three hydraulic
components (e.g., a filter or other component across which a
measurable pressure drop exists), each with a separate upstream
circuit, are arranged so as to have a common downstream passage.
Traditionally, differential pressure measurements across each of
the components HC1, HC2, HC3 would require two separate pressure
sensors, one of which would be placed upstream, and the other,
downstream, of the component. As such, for the system shown in FIG.
13, at least four separate pressure sensors (i.e., one at each
upstream circuit, and one at the common downstream passage) would
have to be used.
[0051] Taking advantage of the principles discussed herein,
however, embodiments of the present invention allow for the use of
fewer sensing devices. For example, only three sensor components of
the type discussed in connection with FIGS. 2-12 need be used to
calculate differential pressures across all of the components HC1,
HC2, and HC3. This is especially true when the components HC1, HC2,
and HC3 share neither a common upstream passage nor a common
downstream passage.
[0052] When either a common upstream passage or a common downstream
passage exists, however, an alternative embodiment of the present
invention enables calculation of all of the differential pressures
using a single MEMS sensor component (i.e., a single-body
differential pressure sensing device). Thus, with reference to the
schematic of FIG. 13, a single sensor component having four sensor
packages is used, wherein three pressure sensor packages are used
to monitor the three separate upstream pressures of the system, and
one pressure sensor package is used to monitor the common
downstream pressure, thus allowing for a smaller, lighter, and more
reliable hydraulic system.
[0053] FIGS. 14-16 show a sensor component 700 that is adapted to
detect differential pressures across two separate hydraulic
components that share either an upstream or a downstream passage.
This arrangement would utilize three sensor packages, each having
at least one MEMS pressure sensor. Accordingly, sensor component
700 includes three sensor-package receptacles 781, 783, 785, two of
which may receive sensor packages for monitoring pressures in the
two separate (e.g., upstream) circuits, and the third may receive a
sensor package for monitoring pressure at the common (e.g.,
downstream) passage.
[0054] It is noted that each of the sensor packages mentioned above
may include additional sensors, e.g., one or more MEMS temperature
sensors in addition to the at least one MEMS pressure sensor. Also,
as shown by way of example in FIG. 14, the sensor component 700 may
optionally include, at a bottom face 791 thereof, a separate sensor
package 790 for flow measurement. When this is the case, the sensor
component 700 also includes an electrical lead passage 787 which
provides a conduit leading away from the fluid flow sensor package
790.
[0055] As shown in FIGS. 14 and 16, the receptacles 781,783,785 are
in flow communication with separate pressure-port apertures
742a,742b,742c, respectively. Thus, as discussed previously in
connection with the embodiment shown in FIGS. 4 and 6, each of the
sensor packages contained in the receptacles 781,783,785 may be
configured to measure properties of the fluid at a different
location by porting the fluid to a sensor package through a
respective pressure-port aperture 742a,742b,742c. This may be done,
for example, by using channels that are similar to channel 526
shown in FIG. 4. In this regard, an isolation seal 720a, such as an
O-ring, may be used to isolate system pressure between
pressure-port apertures 742a and 742b. Similarly, an isolation seal
720b may be used to isolate system pressure between pressure-port
apertures 742b and 742c. In addition, the sensor component 700 may
include a third isolation seal 714 to isolate the sensor component
from the atmosphere (see, e.g., housing seal 514 in FIG. 4).
[0056] Data collected using the multiplicity of sensors and/or
sensor packages may be processed and/or transmitted through the use
of electrical conductors and data-processing devices. To this end,
sensor component 700 includes an electrical housing 715 which may
include electrical conductors, one or more processors, and/or
conductive pins (within an electrical connector 710) which may be
configured to allow transmission of data to/from a data processing
device.
[0057] In addition, the sensor component 700 may include a visual
warning light, an audible alarm, or other warning mechanism that is
configured to indicate an out-of-range condition of the fluid for
each of the hydraulic components being monitored. Moreover, similar
to flange 680 shown in FIG. 11, sensor component 700 may include a
mounting flange 780 that is configured to be secured to a filter
manifold (not shown), thus holding the sensor component in
place.
[0058] FIGS. 17-20 show an alternative embodiment, wherein
measurement data may be wirelessly transmitted to a remote signal
receiver 852 (i.e., a signal receiver that is not electrically
connected to the sensor component). A filter element 2, having an
end cap 9 (see FIGS. 1A and 1B), is normally housed in a bowl, or
casing, 850. In this embodiment, a sensor component 860 may be
placed in a port 868, which may be an axial opening through the end
cap 9. The sensor component 860 may generally be of the types
discussed in connection with FIGS. 2-16, where a plurality of
sensor packages, each having one or more MEMS sensors, are included
within a single sensor component. Thus, although FIGS. 17-20 depict
a wireless differential pressure device, wherein a single sensor
component 860 is configured to measure a differential pressure
using a plurality of sensor packages and MEMS pressure sensors that
are in communication with the unfiltered and filtered fluids, it
will nevertheless be understood that such depiction is by way of
example only. That is, the features of the invention discussed
herein may be applied to sensor components that enable measurement
of properties other than (or in addition to) the fluid's upstream
and downstream pressures, as well as to configurations in which
redundant sensors and/or sensor packages may be used.
[0059] As shown in FIG. 19, the sensor component 860 includes a
sensor-component housing 880 which, in a preferred embodiment, is
adapted to be snapped into the port 868. In this way, an embodiment
of the invention provides a re-usable sensor component for use with
a filter element 2 which, itself, may be a throw-away component.
The sensor component 860 may include a sealing member 870, such as,
for example, an O-ring, so as to provide a fluid-tight interface
between the sensor port 868 and the housing 880, thus preventing
any flow bypass through the port 868.
[0060] The sensor component 860 may be retained in the port 868
using one or more retaining braces 862, 864, 866, which may be
overlapped. In one embodiment, each of the retaining braces 862,
864, 866 includes transverse apertures 863, 865, 867, respectively,
which come into alignment with end cap apertures 869. The end cap 9
and the brace(s) are then held together by passing connection means
861, such as pins, or snap members, through the end cap apertures
869 and the transverse apertures 863 (865, 867).
[0061] As has been discussed in connection with embodiments
described previously, the sensor component 860 may also include
hardware, including one or more processors, electronics, etc. for
processing measurement data prior to transmission. In addition, the
sensor component 860 may include a power supply 890. In a preferred
embodiment, the power supply 890 includes a battery, which may be
rechargeable, and which provides the sensor component 860 with
stand-alone, wireless, functioning capabilities.
[0062] FIGS. 18 and 20 show an embodiment of the casing 850 and
remote signal receiver 852 of the present invention. The casing, or
bowl, has a top end 858 and a bottom end 851, wherein the latter
may be proximate the end of the filter element 2 which has the end
cap 9 mounted thereon (see, e.g., FIG. 17). The signal receiver 852
includes a receiver housing 853, as well as a power supply and
hardware (e.g., processor, electronics, etc.) 857 that are encased
within the housing 853 and may be locked in place using an insert
856. The insert 856 may be, e.g., a nylon thread-lock insert. As
with the sensor component 860, the power supply of the signal
receiver 852 may include a rechargeable battery, thereby providing
a stand-alone, self-powered signal receiving unit. The signal
receiver 852 may be coupled to the bottom end 851 of the casing
850, e.g., by providing mutually-mating threaded surfaces. In a
preferred embodiment, the signal receiver 852 also includes a
warning mechanism 854, such as a visual (LED) indicator.
[0063] In practice, the filter element 2 having a sensor component
860 in an end cap 9 thereof is housed by the casing 850 having a
signal receiver 852 in a bottom end 851 thereof. The sensor
component includes sensor packages that are in communication with
the unfiltered and filtered fluids. Thus, as fluid flows through
the filter, the sensor component 860 determines a differential
pressure across the filter element 2. In one embodiment, the
measurement data is then transmitted, wirelessly, to the signal
receiver 852, when a predetermined differential pressure is
reached. In another embodiment, data is wirelessly transmitted in
predetermined intervals, or continuously in real time.
[0064] Depending on the type and properties of the fluid being
filtered, the data transmission between the sensor component 860
and the signal receiver 852 may be achieved through RF signals,
ultrasonically, or through other means of wireless communication.
Once received by the signal receiver 852, the data may be either
processed locally or transmitted to a central computer or data
processing device, as discussed with respect to the embodiments of
FIGS. 2-16. In addition, the sensor component 860 may comprise a
warning mechanism 854, such as a visual warning light, an audible
alarm, or similar mechanism that is configured to indicate an
out-of-range condition of the fluid (e.g., when a pre-set level is
reached). Thus, in various applications, a condition triggering the
warning mechanism 854 may be based on measurement data transmitted
to the signal receiver 852 relating to pressure, temperature, flow
rate, differential pressure, and/or other fluid or filtration
characteristics.
[0065] In one embodiment, the invention may include a sleep-mode
feature, wherein the MEMS sensors of the sensor component 860, as
well as the signal receiver 852, are configured to remain in an
unactuated state in the absence of fluid flow. Once fluid flow has
been initiated, the sensors become actuated, so that measurement
data can now be taken. In addition, the signal receiver 852 will
become actuated upon receipt of measurement data. When in the
sleep-mode, the sensor component's power supply is configured to
utilize minute amounts of current, e.g., on the order of
micro-amperes. As such, once activated, the power supply will
sustain the sensor component as a self-powered unit for upwards of
6000 hours. Similarly, once activated, the signal receiver 852 will
remain self-sustaining for upwards of 3000 hours. As noted before,
the sensor component 860 and the signal receiver 852 may be removed
or replaced when the filter element 2 is replaced with a new filter
element.
[0066] While the description above refers to particular embodiments
of the present invention, it will be understood that many
modifications may be made without departing from the spirit
thereof. The accompanying claims are intended to cover such
modifications as would fall within the true scope and spirit of the
present invention.
[0067] The presently disclosed embodiments are, therefore, to be
considered in all respects as illustrative and not restrictive, the
scope of the invention being indicated by the appended claims
rather than the foregoing description. All changes that come within
the meaning, and range of equivalency, of the claims are intended
to be embraced therein.
* * * * *