U.S. patent application number 11/358662 was filed with the patent office on 2007-09-13 for twin lubrication tank filling system.
This patent application is currently assigned to Hamilton Sundstrand Corporation. Invention is credited to Jeffrey C. Brill, Michael J. Rollins, Mark N. Shatz.
Application Number | 20070209880 11/358662 |
Document ID | / |
Family ID | 38477800 |
Filed Date | 2007-09-13 |
United States Patent
Application |
20070209880 |
Kind Code |
A1 |
Rollins; Michael J. ; et
al. |
September 13, 2007 |
Twin lubrication tank filling system
Abstract
A twin lubrication oil tank filling system with a single oil
fill port that prevents overfilling of both a primary oil tank and
a secondary oil with a gravity fill system by directing oil
primarily into the secondary oil tank by means of a special oil
diverter, a float valve for the secondary oil tank that closes when
the oil level in the secondary tank reaches a full level to cause
additional oil flow to pour into the primary oil tank and a float
valve for the primary oil tank that closes when the oil level in
the primary tank reaches a full level.
Inventors: |
Rollins; Michael J.;
(Lakeside, CA) ; Shatz; Mark N.; (San Diego,
CA) ; Brill; Jeffrey C.; (Poway, CA) |
Correspondence
Address: |
Hamilton Sundstrand Corporation
4747 Harrison Avenue
P.O. Box 7002
Rockford
IL
61125-7002
US
|
Assignee: |
Hamilton Sundstrand
Corporation
|
Family ID: |
38477800 |
Appl. No.: |
11/358662 |
Filed: |
February 20, 2006 |
Current U.S.
Class: |
184/65 |
Current CPC
Class: |
F16N 19/00 20130101;
Y10T 137/4824 20150401; Y10T 137/7433 20150401; F16N 37/00
20130101; Y10T 137/86212 20150401; Y10T 137/469 20150401 |
Class at
Publication: |
184/065 |
International
Class: |
F16N 7/02 20060101
F16N007/02 |
Claims
1. A twin lubrication oil tank filling system with a single oil
fill port that prevents overfilling of both a primary oil tank and
a secondary oil tank, comprising: a gravity fill system comprising
an oil diverter that directs lubrication oil primarily into the
secondary oil tank; a float valve for the secondary oil tank to
close oil flow into the secondary tank when the lubrication oil
reaches a full level in the secondary tank and causes additional
oil flow to pour into the primary oil tank; and a float valve for
the primary oil tank to close oil flow into the secondary oil tank
when the lubrication oil reaches a full level in the primary oil
tank.
2. The twin lubrication oil tank filling system of claim 1, wherein
the oil diverter comprises an aperture positioned over the float
valve for the secondary oil tank.
3. The twin lubrication oil tank filling system of claim 1, wherein
the oil diverter comprises an inclined surface and a spout
positioned over the float valve for the secondary oil tank.
4. The twin lubrication oil tank filling system of claim 1, wherein
the float valves are mounted on a baffle plate that covers the
primary and secondary oil tanks.
5. The twin lubrication oil tank filling system of claim 4, wherein
the gravity fill system further comprises an oil hurdle mounted on
the baffle plate between the float valve for the secondary oil tank
and the float valve for the primary oil tank such that flow of oil
after the float valve for the secondary oil tank closes must spill
over the oil hurdle to reach the primary oil tank.
6. The twin oil tank filling system of claim 1, wherein the gravity
fill system comprises an oil inlet and the oil diverter is located
underside the oil inlet.
7. The twin oil tank filling system of claim 6, further comprising
an oil chamber formed between the baffle plate and the oil diverter
to retain excess lubrication oil poured into the oil inlet.
8. The twin oil tank filling system of claim 1, wherein each float
valve comprises an external float.
9. The twin oil tank filling system of claim 8, wherein each float
valve comprises a generally cylindrical support member comprising
at least one aperture along an upper end of the support member that
communicates with an inlet port of the float valve and the external
float comprises a generally annular float that slides along the
support member, wherein the external float covers the support
member aperture as it rises toward the float valve inlet port to
shut the float valve.
10. The twin oil tank filling system of claim 1, in combination
with a primary oil tank and a secondary oil tank.
11. A twin lubrication oil tank filling system with a single oil
fill port that prevents overfilling of both a primary oil tank and
a secondary oil tank, comprising: a gravity fill system comprising
an oil inlet with an oil diverter that directs lubrication oil
primarily into the secondary oil tank and an oil chamber between
the oil inlet and the primary and secondary oil tanks for retaining
excess lubrication oil poured into the oil inlet; an external float
valve for the secondary oil tank to close oil flow into the
secondary tank when the lubrication oil reaches a full level in the
secondary tank and causes additional oil flow to pour through an
oil chamber into the primary oil tank; and an external float valve
for the primary oil tank to close oil flow into the secondary tank
when the lubrication oil reaches a full level in the primary oil
tank.
12. The twin lubrication oil tank filling system of claim 11,
wherein the oil diverter comprises an aperture positioned over the
float valve for the secondary oil tank.
13. The twin lubrication oil tank filling system of claim 11,
wherein the oil diverter comprises an inclined surface and a spout
positioned over the float valve for the secondary oil tank.
14. The twin lubrication oil tank filling system of claim 11,
wherein the float valves are mounted on a baffle plate that covers
the primary and secondary oil tanks.
15. The twin lubrication oil tank filling system of claim 14,
wherein the gravity fill system further comprises an oil hurdle
mounted in the oil chamber on the baffle plate between the float
valve for the secondary oil tank and the float valve for the
primary oil tank such that flow of oil after the float valve for
the secondary oil tank closes must spill over the oil hurdle to
reach the primary oil tank.
16. The twin oil tank filling system of claim 11, wherein each
external float valve comprises a generally cylindrical support
member with at least one aperture that communicates with an inlet
port of the float valve and a generally annular external float that
slides along the support member, wherein the external float covers
the support member aperture as it rises toward the float valve
inlet port to shut the float valve.
17. The twin oil tank filling system of claim 11, in combination
with a primary oil tank and a secondary oil tank.
18. An external float valve, comprising: a generally cylindrical
support member comprising at least one aperture along an upper end
of the support member that communicates with an inlet port of the
float valve; and a generally annular external float that slides
along the support member, wherein the external float covers the
support member aperture as it rises toward the float valve inlet
port to shut the float valve.
19. The external float valve of claim 18, further comprising a
mounting flange on an upper end of the float valve.
20. The external float valve of claim 19, wherein the float valve
inlet port passes through the mounting flange.
21. The external float valve of claim 18, wherein the support
member further comprises a float stop that protrudes from a lower
end of the support member to limit travel of the external float
beyond the lower end of the support member.
22. The external float valve of claim 21, wherein the float stop
comprises a retaining ring attached to the support member.
23. The external float valve of claim 18, wherein the support
member comprises three apertures along its upper end that
communicate with the float valve inlet port.
24. An external float valve, comprising: a mounting flange on an
upper end of the float valve; an inlet port for the float valve
that passes through the mounting flange; a generally cylindrical
support member comprising at least one aperture along an upper end
of the support member that communicates with the inlet port of the
float valve and a float stop that protrudes form a lower end of the
support member; and a generally annular external float that slides
along the support member between the mounting flange and the float
stop, wherein the external float covers the support member aperture
as it rises toward the float valve inlet port to shut the float
valve.
25. The external float valve of claim 24, wherein the float stop
comprises a retaining ring attached to the support member.
26. The external float valve of claim 24, wherein the support
member comprises three apertures along its upper end that
communicate with the float valve inlet port.
Description
FIELD OF THE INVENTION
[0001] The invention relates to lubrication systems for machinery,
and more particularly to a twin lubrication oil tank filling system
with a common lubrication oil fill port for machinery that requires
two separate lubrication oil systems.
BACKGROUND OF THE INVENTION
[0002] A gearbox assembly to couple a prime mover to a load
generally requires a lubrication system for lubricating its gears
and bearings with lubrication oil. For example, an aeronautical
auxiliary power unit (APU) has such a gearbox that connects a prime
mover in the form of a gas turbine engine to loads such as a load
compressor, electric generator and hydraulic pump. A lubrication
oil tank generally mounts within the gearbox housing to provide a
reservoir of such lubrication oil for the gearbox lubrication
system.
[0003] Loads coupled to the gearbox may have their own lubrication
system. For instance, the generator connected to such a gearbox may
require lubrication by means of a lubrication system using
lubrication oil stored in a lubrication oil tank. When the gearbox
and generator are of such design that their lubrication systems
integrate together, it is usual practice to provide a single
lubrication oil tank as a reservoir for both the gearbox and the
generator.
[0004] When a gearbox design requires separate oil systems for the
gearbox and the generator, each system with a separate oil tank but
with a common oil fill port, it is difficult to insure that both
tanks fill with lubrication without overfilling one tank or the
other. To prevent overfill, some means must be included for
periodically filling both tanks with lubrication oil simultaneously
without overfilling either.
[0005] A problem with this design has been that the float valves
with internal floats to perform the tank closing operations do not
perform the closing operation as required. In particular, although
the valve floats generally close the tanks upon filling as
required, they tend to stick in the closed position after shutting,
thereby interfering with refilling of the tanks. Therefore, there
is a need for valves that function to seal the generator and
gearbox tanks in sequence to prevent overfilling either tank and do
not stick in the closed position.
SUMMARY OF THE INVENTION
[0006] The invention comprises a twin lubrication oil tank filling
system with a single oil fill port that prevents overfilling a
primary oil tank and a secondary oil tank. A gravity fill system
directs oil to flow primarily into the secondary oil tank. A float
valve for the secondary oil tank closes when the lubrication oil
reaches a full level in the secondary tank and forces additional
oil flow to pour into the primary oil tank. A float valve for the
primary tank closes when the lubrication oil reaches a full level
in the primary tank, and any additional oil flow spills out the oil
fill port. The float valves may comprise a special float valve that
has a generally annular float that slides upon a generally
cylindrical support member with oil fill holes. As the oil level
rises, so does the float until it covers the oil fill holes,
thereby terminating flow.
[0007] In one possible embodiment, the invention comprises a twin
lubrication oil tank filling system with a single oil fill port
that prevents overfilling of both a primary oil tank and a
secondary oil tank, comprising: a gravity fill system comprising an
oil diverter that directs lubrication oil primarily into the
secondary oil tank; a float valve for the secondary oil tank to
close oil flow into the secondary tank when the lubrication oil
reaches a full level in the secondary tank and causes additional
oil flow to pour into the primary oil tank; and a float valve for
the primary oil tank to close oil flow into the secondary tank when
the lubrication oil reaches a full level in the primary oil
tank.
DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a cut-away side view of a gearbox that
incorporates a twin lubrication oil tank filling system with a
primary oil tank and a secondary oil tank according to one possible
embodiment of the invention that shows the primary oil tank only
partially full and the secondary oil tank empty.
[0009] FIG. 2 is a cut-away side view of one possible embodiment of
a float valve with an external float according to the
invention.
[0010] FIG. 3 is a cut-away side view of the gearbox that shows the
primary oil tank only partially full and the secondary oil tank
full.
[0011] FIG. 4 is a cut-away side view of the gearbox that shows
both the primary oil tank and the secondary oil tank full.
DETAILED DESCRIPTION OF THE INVENTION
[0012] FIG. 1 is a cut-away side view of machinery, such as a
gearbox 2, that incorporates a twin lubrication oil tank filling
system 4 according to one possible embodiment of the invention. By
way of example as illustrated, the gearbox 2 is designed for an
aeronautical APU, but the gearbox 2 may be configured for any other
application where it may be used to couple a prime mover to a load.
The twin tank filling system 4 comprises a primary oil tank 6 to
supply oil for the gearbox 2 and a secondary oil tank 8 to supply
oil to at least one load or accessory attached to the gearbox 2,
such as a generator (not shown).
[0013] The primary oil tank 6 and the secondary oil tank 8 have a
"full" level at the same height as controlled by a baffle plate 10
common to both the primary oil tank 6 and the secondary oil tank 8.
A float valve 12 sits in the primary oil tank 6. Another float
valve 12 sits in the secondary oil tank 8. Each float valve 12
mounts in a mating aperture 14 that passes through the baffle plate
10.
[0014] FIG. 2 is a cut-away side view of one possible embodiment of
a float valve 12 with an external float according to the invention.
It is understood, however, that the present invention could utilise
other types of float valves. A generally annular exterior float 16
slides along a generally cylindrical float support member 18. A
float stop 20, such as a retainer ring attached to the support
member 18 as shown, protrudes near a lower end of the support
member 18 to limit travel of the float 16 beyond the lower end of
the support member 18. The support member 18 has at least one
aperture 22, and preferably three as shown. Each aperture 22 passes
through at least a portion of the support member 18 to communicate
with a float valve inlet port 24 that passes through a mounting
flange 26 on an upper end of the float 12. The mounting flange 26
has a shape that is suitable for mounting to its mating aperture 14
in the baffle 10.
[0015] As the float 16 starts to float due to a rising oil level,
it slides upward along the support member 18 toward the mounting
flange 26, it starts to cover the apertures 22, thereby blocking
any fluid communication between the inlet port 24 and the apertures
22. This condition occurs when the primary oil tank 6 or the
secondary oil tank reaches a "full" level established by the baffle
10. As the oil level decreases, such as by consumption, the float
16 slides downward along the support member 18 away from the
mounting flange 26, thereby uncovering the apertures 22 and
restoring fluid communication between the inlet port 24 and the
aperture 22.
[0016] FIG. 1 shows the gearbox 2 with the primary oil tank 6 only
partially full and the secondary oil tank 8 empty. The floats 16
for each of the float valves sit along their respective support
members downward away from their respective apertures 22, thereby
permitting oil to flow through their respective inlet ports 24. An
oil chamber 28 mounts over the baffle 10 to confine lubricating oil
poured into an oil inlet 30 mounted above the oil chamber 28. The
oil inlet 30 receives lubricating oil and it has a oil diverter 32
along an underside of the oil inlet 30 to direct lubricating oil
flow out of the oil inlet 30 primarily into the secondary oil tank
8. The oil diverter 32 may be a simple aperture generally
positioned over the float valve 12 for the secondary oil tank 8,
but it most conveniently comprises an inclined surface 34 and a
spout 36 along a lower part of the oil inlet 30 positioned over the
float valve 12 for the secondary oil tank 8 to direct the
lubricating oil primarily into the secondary oil tank 8. The spout
36 may conveniently comprise a spout-shaped oil filter comprising a
course screen material. An oil hurdle 38 comprising a generally
bulkhead-like structure mounted across the baffle 10 extending
upward within the oil chamber 28 between the float valves 12 for
the primary oil tank 6 and the secondary oil tank 8 serves to
insure that the secondary oil tank 8 fills first.
[0017] FIG. 3 is a cut-away side view of the gearbox 2 that shows
the primary oil tank 6 only partially full and the secondary oil
tank 8 full. The float 16 for the float valve 12 in the secondary
oil tank 8 now floats upward along the float support 18 due to the
oil level in the secondary oil tank 8 to a position that covers the
apertures 22 and block the communication of fluid flow between the
inlet port 24 and the apertures 22, thus shutting the float valve
12 for the secondary oil tank 8. Oil then starts to fill the oil
chamber 28 to a level that exceeds the height of the oil hurdle 38.
As the oil spills over the oil hurdle 38, it begins to flow into
the primary oil tank 6 by way of its float valve 12, which is still
open.
[0018] FIG. 4 is a cut-away side view of the gearbox 2 that shows
both the primary oil tank 6 and the secondary oil tank 8 full. The
float 16 for each of the float valves 12 in the primary oil tank 6
and the secondary oil tank 8 now floats upward along the float
support 18 due to the oil level in the secondary oil tank 8 to a
position that covers the apertures 22 and block the communication
of fluid flow between the inlet port 24 and the apertures 22, thus
shutting the float valves 12 in both the primary oil tank 6 and the
secondary oil tank 8. Any additional flow of oil causes the oil
chamber 28 to start to fill. If the oil chamber completely fills
with oil, the oil level may increase to the point where it spills
out of the inlet port 28, but it is thus impossible to overfill the
primary tank 6 and the secondary tank 8. The oil inlet 30, the oil
chamber 28 and the baffle 10 thus serve as a gravity oil fill
system that directs oil primarily into the secondary oil tank 8
until the float valve 12 for the secondary oil tank 8 closes, so
that once the secondary oil tank float valve 12 closes flow spills
over the baffle 10 and pours into the primary oil tank 6 until the
float valve 12 for the primary oil tank 6 closes, thereby
preventing overfilling of either tank through the single oil fill
port
[0019] Described above is a twin lubrication oil tank filling
system with a single oil fill port that prevents overfilling of
both a primary oil and a secondary oil tank with a gravity fill
system by directing oil primarily into the secondary oil tank by
means of a special oil diverter, a float valve for the secondary
oil tank that closes when the oil level in the secondary tank
reaches a full level to cause additional oil flow to pour into the
primary oil tank and a float valve for the primary oil tank that
closes when the oil level in the primary tank reaches a full level.
It should be understood that this embodiment is only an
illustrative implementation of the invention, that the various
parts and arrangement thereof may be changed or substituted, and
that the invention is only limited by the scope of the attached
claims.
* * * * *