U.S. patent application number 10/991492 was filed with the patent office on 2005-05-12 for return-side filter for use in a vehicle transmission.
This patent application is currently assigned to SPX Corporation. Invention is credited to Caldwell, Craig S..
Application Number | 20050098508 10/991492 |
Document ID | / |
Family ID | 25411702 |
Filed Date | 2005-05-12 |
United States Patent
Application |
20050098508 |
Kind Code |
A1 |
Caldwell, Craig S. |
May 12, 2005 |
Return-side filter for use in a vehicle transmission
Abstract
A fluid filtration assembly (10) operable to provide both
return-side and supply-side filtration, as, for example, of a fluid
entering and leaving a sump (14) as it circulates in a vehicle
transmission (12). The fluid filtration assembly (10) broadly
comprises a return-side filter (18) and a supply-side filter (20).
The return-side filter (18) includes a filter media (33) operable
to filter relatively small particles. Fluid flow through the
return-side filter (18) may be accomplished using any of three
described alternative embodiments, including upflow, downflow, and
direct feed. The supply-side filter (20) includes a filter media
(42) for filtering needed fluid as it is drawn back into
circulation. The supply-side filter media (42) is a low restriction
filter media operable to filter only relatively large particles,
thereby decreasing bottle-neck effects and minimizing pressure
drops.
Inventors: |
Caldwell, Craig S.;
(Kenosha, WI) |
Correspondence
Address: |
Baker & Hostetler LLP
Washington Square
Suite 1100
1050 Connecticut Avenue, N.W.
Washington
DC
20036
US
|
Assignee: |
SPX Corporation
|
Family ID: |
25411702 |
Appl. No.: |
10/991492 |
Filed: |
November 19, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10991492 |
Nov 19, 2004 |
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09899894 |
Jul 6, 2001 |
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6835306 |
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Current U.S.
Class: |
210/805 ;
210/167.08; 210/455 |
Current CPC
Class: |
F16H 57/0404 20130101;
B01D 29/56 20130101; B01D 29/05 20130101; B01D 35/0273
20130101 |
Class at
Publication: |
210/805 ;
210/168; 210/455 |
International
Class: |
B01D 035/00 |
Claims
1. (canceled)
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. (canceled)
10. A return-side filter for filtering a return fluid in a vehicle
transmission, the return-side filter comprising: a lid having a top
surface; an inlet operable to direct the return fluid into the lid;
a filter media spaced below the top surface and the inlet and at
least substantially spanning the lid and operable to filter the
return fluid; and an outlet located below the filter media and
operable to release the return fluid.
11. The return-side filter as set forth in claim 10, further
including spacers projecting downwardly from the top surface of the
lid and operable to space the filter media below the top
surface.
12. The return-side filter as set forth in claim 10, further
including a pan positioned below the filter media.
13. The return-side filter as set forth in claim 12, wherein the
outlet comprises a slot in the pan.
14. A vehicle transmission utilizing a fluid, the vehicle
transmission comprising: a sump operable to receive the fluid via a
sump inlet; a return-side filter operable to filter at least a
return fluid portion of the fluid, the return-side filter including
a lid having a top surface; a return-side inlet coupled with the
sump inlet and operable to direct the return fluid into the lid; a
filter media spaced below the top surface and the inlet and at
least substantially spanning the lid and operable to filter the
return fluid; and an outlet located below the filter media and
operable to release the return fluid.
15. The return-side filter as set forth in claim 14, further
including a spacers projecting downwardly from the top surface of
the lid and operable to space the filter media below the top
surface.
16. The vehicle transmission as set forth in claim 14, wherein the
return fluid is released into the sump.
17. The return-side filter as set forth in claim 14, further
including a pan positioned below the filter media.
18. The return-side filter as set forth in claim 17, wherein the
outlet comprises a slot in the pan.
19. A fluid filtration assembly for filtering a fluid in a vehicle
transmission, the fluid filtration assembly comprising: a
return-side inlet operable to receive a return fluid, a return-side
filter media operable to filter the return fluid, and a return-side
outlet operable to release the return fluid directly into a
supply-side filter.
20. The fluid filtration assembly as set forth in claim 19, wherein
the supply-side inlet and the return-side outlet are coupled by a
flexible hose.
21. The fluid filtration assembly as set forth in claim 19, wherein
the supply-side inlet and the return-side outlet are coupled by a
substantially inflexible duct.
22. The fluid filtration assembly as set forth in claim 19, wherein
the return-side filter media is operable to filter relatively small
particulates from the return fluid.
23. The fluid filtration assembly as set forth in claim 19, wherein
the supply-side filter is operable to filter the return fluid using
a supply-side filter media.
24. A vehicle transmission utilizing a fluid, the vehicle
transmission comprising: a sump operable to receive the fluid via a
sump inlet and to release the fluid via a sump outlet; and a fluid
filtration assembly located in the sump and operable to filter the
fluid, the fluid filtration assembly including a return-side filter
including a return-side inlet coupled with the sump inlet and
operable to receive at least a return fluid portion of the fluid, a
return-side filter media operable to filter the return fluid, a
return-side outlet operable to release the return fluid directly
into a supply-side filter.
25. The fluid filtration assembly as set forth in claim 24, wherein
the supply-side inlet and the return-side outlet are coupled by a
flexible hose.
26. The fluid filtration assembly as set forth in claim 24, wherein
the supply-side inlet and the return side outlet are coupled by a
substantially inflexible duct.
27. The fluid filtration assembly as set forth in claim 24, wherein
the return-side filter media is operable to filter relatively small
particulates from the return fluid.
28. The fluid filtration assembly as set forth in claim 24, wherein
the supply-side filter is operable to release the return fluid into
the sump outlet.
29. The fluid filtration assembly as set forth in claim 24, wherein
the supply-side filter is operable to filter the return fluid using
a supply-side filter media prior to releasing the return fluid into
the sump outlet.
30. A method of filtering a fluid in a transmission, the method
comprising the steps of: (a) receiving at least a return fluid
portion of the fluid; (b) filtering the return fluid using a
return-side filter media; (c) releasing the return fluid; (d)
receiving a supply fluid; and (e) filtering the supply fluid using
a supply-side filter media.
31. The method as set forth in claim 30, wherein step (b) is
operable to remove relatively small particulates from the return
fluid.
32. The method as set forth in claim 30, wherein step (c) involves
releasing the return fluid into a sump.
33. The method as set forth in claim 32, wherein step (d) involves
receiving the supply fluid from the sump.
34. The method as set forth in claim 30, wherein the supply fluid
comprises the return fluid.
35. The method as set forth in claim 30, wherein step (e) is
operable to remove only relatively large particulates from the
supply fluid.
36. (canceled)
37. (canceled)
38. (canceled)
39. (canceled)
40. (canceled)
41. (canceled)
42. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to systems and methods for
filtering fluids in vehicles. More particularly, the present
invention relates to a fluid filtration assembly and method
combining return-side and supply-side filters to filter a
circulating fluid as it enters and leaves a sump portion of a
vehicle transmission.
[0003] 2. Description of the Prior Art
[0004] As will be appreciated by those with ordinary skill in the
automotive arts, an automatic transmission is a complex hydraulic
circuit whose primary purpose is to allow an engine to operate in a
narrow RPM (revolutions per minute) band while providing a wide
range of output speeds. The transmission uses a fluid, typically a
light oil, to create a hydraulic coupling that converts engine
power to hydraulic pressure. The fluid serves other purposes as
well, including lubrication and heat transfer. As it circulates
through the transmission, the fluid collects damaging particulates
such that it is desirable to filter the fluid at some point prior
to recirculation. Commonly, fluid filtration takes place as the
fluid is drawn back into circulation from a sump or reservoir.
[0005] Unfortunately, existing filtration systems suffer from a
number of disadvantages. Filtering for small particulates, for
example, as the fluid is drawn back into circulation creates a
bottleneck effect that can result in undesirable drops in fluid
pressure. This is of particular concern during cold flow
conditions. Furthermore, because it alone provides all filtration,
the single supply-side filter can clog when tasked to remove large
amounts of contaminant, resulting in poor performance but for
burdensomely frequent filter changes or cleanings.
[0006] It is known in the art to incorporate a spin-on filter to
perform at least some filtration as the fluid enters the sump.
Unfortunately, the nature and design of the spin-on filter is so
substantially different from the typical supply-side filter that no
interchangeability or shared structural components, desirable from
a design and manufacturing standpoint, is possible. Furthermore,
transmission designs are not easily adapted to accommodate the
spin-on filter.
[0007] Due to the above-identified and other problems in the art, a
need exists for an improved fluid filtration assembly or
method.
SUMMARY OF THE INVENTION
[0008] The fluid filtration assembly and method of the present
invention overcomes the above-identified and other problems in the
art to provide a simple and inexpensive integrated assembly
advantageously and efficiently accomplishing both return-side and
supply-side filtration of a fluid as it enters and leaves a sump
portion of a vehicle transmission. This two-stage filtration aids
to mitigate or substantially eliminate bottleneck effects and fluid
pressure drops at the supply-side.
[0009] The preferred fluid filtration assembly comprises a common
housing component; a return-side filter; and a supply-side filter.
The common housing component provides a substantial advantage in
that it allows for design and manufacturing efficiencies not
possible with existing spin-on filter technology. Furthermore, by
sharing the common housing component, be it a bottom, top, or side
wall, the return-side and supply-side filters are integrated into a
single fluid filtration assembly conveniently locatable in the sump
where it is easily accessed for maintenance. Additionally, the
common housing component facilitates the direct flow embodiment
described below.
[0010] The return-side filter is operable to filter at least a
portion of the fluid as it enters or returns to the sump, with any
remaining fluid flowing directly into the sump. The return-side
filter includes a return-side filter media operable to filter both
large and relatively small particulates, and may also include a
magnet operable to trap and hold metal particles or shavings that
would otherwise prematurely clog the filter media. Fluid flow
through the return-side filter may be accomplished using any of
three alternative embodiments, including upflow, downflow, and
direct feed configurations. In the upflow embodiment, the fluid
enters beneath and rises through the return-side filter media to
exit at or near the top of the return-side filter and empty into
the sump. One advantage of the upflow embodiment is that
particulates are allowed to settle out of the fluid before exposure
to the filter media, thereby extending the filter media's
operational life. In the downflow embodiment, the fluid enters
above and flows downward through the return-side filter media to
exit at or near the bottom of the return-side filter and empty into
the sump. In the direct flow embodiment, regardless of where the
fluid enters or how it is filtered within the return-side filter,
the filtered fluid thereafter flows directly to the supply-side
filter rather than into the sump.
[0011] The supply-side filter receives fluid either from the sump,
directly from the return-side filter, or some combination thereof,
filters the fluid again, and then releases the fluid back into
circulation. Because a substantial amount of undesirable
particulates are removed from the fluid by the return-side filter
media, possibly aided by the settling action of the upflow
embodiment, the supply-side filter media can be a low-restriction
filter media operable to remove only relatively large particulates,
which advantageously decreases bottle-neck effects and minimizes
fluid pressure drops.
[0012] In the present invention, it will be appreciated that the
common housing structure, though providing distinct advantages, is
not necessary. Rather, the supply-side and return-side filters may
be independently constructed, though functioning in substantially
the same manner as though they shared common structure.
Furthermore, by itself the return-side filter as herein set forth
provides a distinct advance in the art.
[0013] These and other important features of the present invention
are more fully described in the section titled DETAILED DESCRIPTION
OF A PREFERRED EMBODIMENT, below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] A preferred embodiment of the present invention is described
in detail below with reference to the attached drawing figures,
wherein:
[0015] FIG. 1 is a side elevational view of a preferred embodiment
of the fluid filtration assembly of the present invention, wherein
portions of an automatic transmission are shown in broken lines to
illustrate an operating environment and thereby enhance clarity of
understanding;
[0016] FIG. 2 is a top plan view of a preferred first embodiment of
the fluid filtration assembly of the present invention;
[0017] FIG. 3 is an exploded isometric view of the preferred first
embodiment shown in FIG. 2;
[0018] FIG. 4 is a side elevational fragmentary sectional view
taken along line 4-4 of FIG. 2, wherein arrows are used to
illustrate direction of fluid flow;
[0019] FIG. 5 is an exploded isometric view of a preferred second
embodiment of the fluid filtration assembly the present
invention;
[0020] FIG. 6 is a side elevational fragmentary sectional view of
the preferred second embodiment shown in FIG. 5, wherein arrows are
used to illustrate direction of fluid flow;
[0021] FIG. 7 is an exploded isometric view of a preferred third
embodiment of the fluid filtration assembly of the present
invention;
[0022] FIG. 8 is a top plan view of the preferred third embodiment
shown in FIG. 7;
[0023] FIG. 9 is a side elevational fragmentary sectional view
taken along line 9-9 of FIG. 7, wherein arrows are used to
illustrate direction of fluid flow; and
[0024] FIG. 10 is a preferred fourth embodiment of the fluid
filtration assembly of the present invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0025] Referring to FIGS. 1, 2, and 3, a fluid filtration assembly
10 is shown constructed in accordance with a preferred first
embodiment of the present invention and therefore operable to
provide both return-side and supply-side filtration of a
circulating fluid. The fluid filtration assembly 10 is preferably
located in a sump or reservoir 14 of a transmission 12, and broadly
comprises a common housing component 16; a return-side filter 18;
and a supply-side filter 20.
[0026] The common housing component 16 is shared between the
return-side and supply-side filters 18,20, thereby integrating the
two into a single assembly and providing substantial design and
manufacturing advantages. Furthermore, the common housing component
16, be it a bottom, top, or side wall, allows the two filters 18,20
to be located within the sump 14 where they are conveniently and
efficiently simultaneously accessible for maintenance.
Additionally, the common housing component 16 facilitates the
direct flow embodiment described below.
[0027] In the illustrated embodiments, the common housing component
16 is a common bottom 16 comprising both a return-side pan 24 and a
supply-side pan 26 associated, respectively, with the return-side
and supply-side filters 18,20. The common bottom 16 preferably
presents a plurality of legs 28 projecting downwardly from a bottom
side of each pan 24,26 and operable to rest upon a pan portion 27
of the sump 14 and thereby provide spatial separation within which
the fluid can pool and particulates can settle out. The base
structure 16 is preferably constructed of a suitably lightweight,
durable, and inexpensive material such as nylon that is 30%-33%
glass-filled.
[0028] The return-side filter 18 is operable to receive and filter
at least a return fluid portion of the fluid, with any remaining
fluid emptying directly into the sump pan 27. The return-side
filter 18 broadly comprises a return-side lid 32; the return-side
pan 24; and a return-side filter media 33. The return-side lid 32
is operable to fit over, secure to, and cover that portion of the
common bottom 16 which defines the return-side pan 24. The
return-side lid 32 presents an upwardly opening inlet 34 operable
to receive the return fluid, and a plurality of fluid release slots
36 operable to release the filtered return fluid into the sump pan
27. In alternative embodiments described below, the fluid release
slots 36 appear in the pan 24 rather than the lid 32, or are absent
altogether. The return-side lid 32 is also preferably constructed
of a suitably lightweight, durable, and inexpensive material such
as nylon that is 30%-33% glass-filled.
[0029] The return-side filter media 33 is operable to filter both
large and relatively small particles from the return fluid. The
return-side filter media 33 is preferably held securely in its
operational position between the return-side lid 32 and pan 24 by
spacers 38 projecting downwardly from the former and upwardly from
the latter.
[0030] The supply-side filter 20 is operable to draw, filter, and
return to circulation a supply fluid portion of the fluid, wherein
the supply fluid may comprise in whole or in part the return fluid
or a portion thereof. The supply-side filter 20 broadly comprises a
supply-side lid 40; the supply-side pan 26; and a supply-side
filter media 42. The supply-side lid 40 is operable to fit over,
secure to, and cover that portion of the common bottom 16 which
defines the supply-side pan 26. The supply-side lid 40 presents an
upwardly opening outlet 44 operable to return fluid to circulation
in the transmission 12. The supply-side lid 40 is also preferably
constructed of a suitably lightweight, durable, and inexpensive
material such as nylon that is 30%-33% glass-filled. The
supply-side pan 26 includes a large opening 46 through which fluid
may be drawn from the sump pan 27 for filtration and recirculation
via the outlet 44.
[0031] The supply-side filter media 42 is operable to filter only
relatively large particulates from the fluid. Because it is less
restrictive than the return-side filter media 33, the supply-side
filter media 42 avoids causing or exacerbating undesirable
bottleneck effects and drops in fluid pressure. The supply-side
filter media 42 is preferably held securely in its operational
position between the supply-side lid 40 and pan 26 by spacers 48
projecting downwardly from the former and upwardly from the
latter.
[0032] In operation, referring also to FIG. 4, the fluid filtration
assembly 10 of the present invention is properly installed by
removing the sump pan 27 from the transmission 12, coupling the
return-side inlet 34 and the supply-side outlet 44 with
corresponding components of the transmission 12, and replacing the
sump pan 27 so that the standoffs 28 projecting downwardly from the
common bottom 16 provide spatial separation wherein the fluid can
pool and particulates can settle out.
[0033] Thereafter, as the fluid circulates through the operating
transmission 12, a return fluid portion, possibly as much as
one-half gallon per minute, will enter the return-side inlet 34.
Fluid in excess of this amount is deposited directly into the sump
pan 27. The return fluid is directed under the return-side filter
media 33 to the return-side pan 24 where gravity may cause at least
some particulates to settle out. As the return fluid level rises in
the pan 24, the return fluid is forced against and through the
return-side filter media 33 and then out the fluid release slots 36
to spill over the return-side lid 32 and into the sump pan 27.
[0034] Suction at the supply-side outlet 44 draws needed fluid back
into circulation. This suction causes a supply fluid portion of the
fluid in the sump 14 to be drawn into the supply-side pan 26 via
the large opening 46, against and through the supply-side filter
media 42; and out the outlet 44. As will be appreciated, the supply
fluid may comprise in whole or in part the return fluid or a
portion thereof released into the sump pan 27 by the return-side
filter 20.
[0035] Referring to FIGS. 5 and 6, a preferred alternative second
embodiment of the fluid filtration assembly 110 is shown similarly
operable to provide both inflow and outflow filtration of the
fluid. The fluid filtration assembly 110 is substantially identical
in structure, broadly comprising the common bottom 116; the
return-side filter 118; and the supply-side filter 120. In the
preferred second embodiment, however, the fluid release slots 136
appear in the return-side pan 124 rather than the return-side lid
132. Operational flow of the return fluid through the return-side
filter 118 is over, down, and through the return-side filter media
133, rather than under, up, and through as in the first embodiment
described above. The filtered return fluid then exits via the
release slots 136. Supply-side filter 120 operation is
substantially identical to that described above.
[0036] Referring to FIGS. 7, 8, and 9, a preferred alternative
third embodiment of the fluid filtration assembly 210 is shown
similarly operable to provide both inflow and outflow filtration of
the fluid. The fluid filtration assembly 210 is substantially
similar in structure, broadly comprising the common bottom 216; the
return-side filter 218; and the supply-side filter 220. The
preferred third embodiment eliminates separate return-side and
supply-side lids in favor of a single common lid 248. Furthermore,
return-side fluid release slots are eliminated from both the
return-side lid 232 and pan 224. Instead, a flow hole 250 allows
the filtered return fluid to flow directly from the return-side
filter 218 to the supply-side filter 220. Thus, operational return
fluid flow through the return-side filter 218 may be, as desired,
under, up, and through the return-side filter media 233, or over,
down, and through the return-side filter media 233. Regardless of
flow direction during filtering, the filtered return fluid is
released directly into the supply-side filter 220 via the flow hole
250, whereafter the return fluid may be immediately released into
circulation or filtered again using the supply-side filter media
prior to such release.
[0037] As will be appreciated by those with ordinary skill in the
relevant arts, the flow hole 250 is not limited to the illustrated
flowpath facilitated by the common lid 248. Rather, the flow hole
250 may be implemented as any suitable flowpath connecting the two
filters 218,220, including, for example, a rubber or reinforced
hose or elongated channel or ductwork.
[0038] Referring to FIG. 10 a preferred alternative fourth
embodiment of the fluid filtration assembly 310 is shown wherein
the return-side filter 318 does not share a common housing
component with a supply-side filter. Rather, the return side filter
318 includes a stand-alone return-side pan 324, preferably
constructed of a suitably lightweight, durable, and inexpensive
material such as nylon that is 30%-33% glass-filled. As desired,
the return-side pan 324 may present the plurality of legs (not
shown) projecting downwardly and operable to rest upon the pan
portion (not shown) of the sump (not shown) and thereby provide
spatial separation within which the fluid can pool and particulates
can settle out.
[0039] The return-side filter 318 is operable to receive and filter
at least a return fluid portion of the fluid, with any remaining
fluid emptying directly into the sump pan. In all other respects,
the return-side filter 318 is substantially operable to function as
described above.
[0040] From the preceding description, it can be seen that the
fluid filtration assembly of the present invention, in its various
described embodiments, provides an improved system and method for
filtering a fluid circulating in a vehicle transmission. A number
of design and manufacturing advantages are provided, including dual
filtration; integrated return-side and supply-side filters; common
housing components; mitigated or substantially eliminated
bottleneck effects; and mitigated or substantially eliminated fluid
pressure drops.
[0041] Although the invention has been described with reference to
the three preferred embodiments illustrated in the attached
drawings, it is noted that equivalents may be employed and
substitutions made herein without departing from the scope of the
invention as recited in the claims. For example, it is contemplated
that the lid, bottom, pan, and filter shapes and construction may
be altered or adapted to particular applications while still
achieving the same effects and advantages, both recited and
unrecited, as the present invention.
[0042] Having thus described the preferred embodiment of the
invention, what is claimed as new and desired to be protected by
Letters Patent includes the following:
* * * * *