U.S. patent application number 09/771150 was filed with the patent office on 2002-08-01 for magnetically actuated valve system.
This patent application is currently assigned to VACCO Industries Inc.. Invention is credited to Cardin, Joseph M..
Application Number | 20020100508 09/771150 |
Document ID | / |
Family ID | 25090877 |
Filed Date | 2002-08-01 |
United States Patent
Application |
20020100508 |
Kind Code |
A1 |
Cardin, Joseph M. |
August 1, 2002 |
MAGNETICALLY ACTUATED VALVE SYSTEM
Abstract
A magnetically actuated valve system for controlling fluid flow
through a first conduit and a second conduit. A first sealing
structure associated with the first conduit is moveable in response
to a magnetic force to an open position and spring biased toward a
closed position. The closed position prevents fluid flow through
the first conduit. A second sealing structure associated with the
second conduit is moveable in response to a magnetic force in a
second direction, substantially opposite to the first direction, to
an open position and biased toward a closed position. The closed
position prevents fluid flow through the second conduit. A magnetic
actuator assembly is constructed and arranged to actuate the first
and second sealing assemblies substantially simultaneously by
moving the first and second sealing structures in the first and
second directions, respectively.
Inventors: |
Cardin, Joseph M.; (Yorba
Linda, CA) |
Correspondence
Address: |
Mr. charan Brahma
PILLSBURY WINTHROP LLP
Suite 2800
725 South Figueroa Street
Los Angeles
CA
90017-5406
US
|
Assignee: |
VACCO Industries Inc.
|
Family ID: |
25090877 |
Appl. No.: |
09/771150 |
Filed: |
January 26, 2001 |
Current U.S.
Class: |
137/595 |
Current CPC
Class: |
Y10T 137/87161 20150401;
F16K 31/06 20130101; F16K 11/10 20130101; F02K 9/58 20130101; Y10T
137/87981 20150401 |
Class at
Publication: |
137/595 |
International
Class: |
F17D 001/04 |
Claims
What is claimed is:
1. A magnetically actuated valve system, comprising: a first
conduit; a second conduit; a first sealing structure, moveable in
response to a magnetic force in a first direction to an open
position and biased toward a closed position, the closed position
preventing fluid flow through the first conduit; a second sealing
structure, moveable in response to a magnetic force in a second
direction, substantially opposite to the first direction, to an
open position and biased toward a closed position, the closed
position preventing fluid flow through the second conduit; and a
magnetic actuator assembly, constructed and arranged to actuate the
first and second sealing structures substantially simultaneously by
moving the first and second sealing structures in the first and
second directions, respectively.
2. A magnetically actuated valve system as in claim 1, further
comprising: a first manifold assembly in which the first conduit is
disposed; and a second manifold assembly in which the second
conduit is disposed, such that separate fluids may be carried
within each of the first and second conduits.
3. A magnetically actuated valve system as in claim 1, wherein each
sealing structure is spring biased toward the closed position.
4. A magnetically actuated valve system as in claim 2, wherein each
manifold assembly comprises: an inlet; a main body portion having
said first conduit therein; and an outlet for transporting a fuel
from said inlet through said conduit to said outlet.
5. A magnetically actuated valve system as in claim 1, wherein each
sealing structure comprises: a respective armature member, made of
high flux capacity material; a sealing portion carried by said
armature member for preventing fluid flow through a respective one
of the first and second conduits; and a spring member constructed
and arranged to bias said sealing structure in the closed
position.
6. A magnetically actuated valve system as in claim 5, wherein each
sealing portion is made of polytetrafluoroethylene.
7. A magnetically actuated valve system as in claim 1, wherein said
magnetic actuator assembly comprises: a conductive coil; a core
extending through said coil; and a case surrounding said coil.
8. A magnetically actuated valve system as in claim 1, wherein: the
first sealing structure and the second sealing structure move
toward one another when moving into the open position.
9. A magnetically actuated valve system as in claim 1, further
comprising: a third sealing structure, disposed downstream of the
first sealing structure, moveable in response to a magnetic force
in the first direction to an open position and biased toward a
closed position, the closed position preventing fluid flow through
the first conduit; a fourth sealing structure, disposed downstream
of the second sealing structure and moveable in response to a
magnetic force in the second direction to an open position and
spring biased toward a closed position, the closed position
preventing fluid flow through the second conduit; and a second
magnetic actuator assembly, disposed between the first conduit and
the second conduit, constructed and arranged to actuate the second
and third sealing assemblies substantially simultaneously be moving
the second and third sealing structures in the first and second
directions, respectively.
10. A magnetically actuated valve system as in claim 9, further
comprising first and second manifold assemblies, wherein the first
and second conduits are disposed in the first and second manifold
assemblies.
11. A magnetically actuated valve system as in claim 10, wherein
each manifold assembly comprises: an inlet; a main body portion
having said first conduit etched therein; and an outlet for
transporting a fuel from said inlet through said first conduit to
said outlet.
12. A magnetically actuated valve system as in claim 9, wherein the
first and third sealing structures are disposed as parallel
elements of a first fluid circuit which includes the first conduit
and said second and fourth sealing structures are disposed as
parallel elements of a second fluid circuit which includes the
second conduit.
13. A magnetically actuated valve system as in claim 12, wherein
each of said sealing structures comprises a respective sealing
portion for preventing fluid flow through a respective one of the
conduits, and a spring member constructed and arranged to bias said
sealing structure toward said closed position.
14. A magnetically actuated valve system as in claim 9, wherein
each magnetic actuator assembly comprises: a conductive coil; a
core extending through said coil; and a case surrounding said
coil.
15. A magnetically actuated valve system as in claim 1, further
comprising: a magnet constructed and arranged to produce a magnetic
biasing force on the first and second sealing structures toward
their open positions insufficient to overcome the bias toward the
closed position, said magnetic actuator assembly constructed and
arranged to produce a first impulse to actuate the first and second
sealing structures toward their respective open positions such that
the magnetic biasing force retains them in their respective open
positions, and to produce a second impulse to overcome the magnetic
biasing force and to actuate the first and second sealing
structures toward their respective closed positions.
16. A thruster valve assembly, comprising: a first manifold
assembly having a first conduit therein and a first valve seat; a
second manifold assembly having a second conduit therein and a
second valve seat, the second conduit being disposed in parallel
with the first conduit; a magnetic actuator housing assembly
disposed between said first and second manifold assemblies; a first
sealing structure disposed between said magnetic actuator housing
assembly and said first manifold assembly, said first sealing
structure being movable to an open position for unblocking said
first valve seat and spring biased toward a closed position for
blocking said first valve seat to prevent fluid flow through the
first conduit; a second sealing structure, disposed between said
magnetic actuator housing assembly and said second manifold
assembly, said second manifold assembly being moveable to an open
position for unblocking said second valve seat and spring biased
toward a closed position for blocking said second valve seat to
prevent fluid flow through the second conduit; a first magnetic
actuator assembly, disposed within a magnetic actuator assembly
receiving portion of said magnetic actuator housing assembly
between the first conduit and the second conduit, constructed and
arranged to exert a magnetic force on the first sealing structure
and the second sealing structure substantially simultaneously, the
magnetic force moving the first sealing structure and the second
sealing structure in respectively opposite directions and into
their respective open positions.
17. A thruster valve assembly as in claim 16, wherein said first
manifold assembly further includes a third valve seat disposed
downstream of the first valve seat and said second manifold
assembly further includes a fourth valve seat disposed downstream
of the second valve seat.
18. A thruster valve assembly as in claim 17, further comprising: a
third sealing structure disposed downstream of the first sealing
structure and between said magnetic actuator housing assembly and
said first manifold assembly, said third sealing structure being
movable to an open position for unblocking said third valve seat
and spring biased toward a closed position for blocking said third
valve seat to prevent fluid flow through the first conduit.
19. A thruster valve assembly as in claim 18, further comprising: a
fourth sealing structure disposed downstream of the second sealing
structure and between said magnetic actuator housing assembly and
said second manifold assembly, said fourth sealing structure being
movable to an open position for unblocking said fourth valve seat
and spring biased toward a closed position for blocking said fourth
valve seat to prevent fluid flow through the second conduit.
20. A thruster valve assembly as in claim 19, further comprising: a
second magnetic actuator assembly disposed within a second magnetic
actuator assembly receiving portion of said magnetic actuator
housing assembly between the first conduit and the second conduit
and constructed and arranged to exert a magnetic force on the third
sealing structure and the fourth sealing structure substantially
simultaneously, the magnetic force moving the third sealing
structure and the fourth sealing structure in respectively opposite
directions into their respective open positions.
21. A thruster valve assembly as in claim 16, wherein: the first
manifold assembly and the second manifold assembly each are made of
a first material, the actuator assembly is made of a second
material, the first manifold assembly, the second manifold assembly
and the actuator assembly are mechanically fastened together, and
each of said sealing structures is enclosed within a respective
manifold assembly.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to a magnetically actuated
valve system and more specifically to a magnetically actuated valve
system in which at least two solenoid valves are actuated by a
single electromagnetic actuator.
BACKGROUND OF THE INVENTION
[0002] In typical electromagnetically actuated propellant valves
used in bi-propellant systems, a first propellant (fuel) flows
through an upstream valve to a downstream valve such that the first
propellant will be directed into contact with a second propellant
(oxidizer) flowing through a second upstream valve to a second
downstream valve within a thruster portion of an engine or the
like, whereby the combined propellant will be ignited. The flow of
each of the first and second propellants is simultaneously
controlled and maintained in the correct proportions by a single
magnetic circuit actuating two magnetically linked valves, each
housed in a manifold assembly.
[0003] U.S. Pat. Nos. 3,443,585, 3,472,277 and 4,223,698 disclose
various magnetically actuated valve systems wherein a single
electromagnetic excitation will actuate each of two valve members,
each of which serves its own pressure-fluid flow. In the '585
patent, a permanent magnet is the common middle element of two
separate solenoid-actuated magnetic circuits. Excitation of one
solenoid opens both valves; excitation of the other solenoid closes
both valves; and the permanent magnet holds the actuated condition
of both valves. The '277 and '698 patents each disclose an
electromagnetic actuating system wherein a single solenoid coil
actuates two magnetically linked valves to open condition, against
the preload of springs to load valve members in the valve-closing
direction. In all cases, construction is highly specialized and
complex, leading to unduly expensive products.
[0004] U.S. Pat. No. 5,450,876 discloses an electromagnetically
actuated multiple-valve construction within a single welded housing
which contains each of two series-connected valves and a single
magnetic circuit for concurrently operating an upstream and a
downstream valve.
[0005] Consequently, there exists a need in the art for a valve
system having the functional advantages of the '876 patent without
a welded construction, which adds weight. There also exists a need
in the art for a magnetically actuated valve system to provide a
pair of magnetically operated valves movable between a power
applied and a power removed position by a magnetic solenoid
actuator assembly for simultaneously controlling and maintaining
first and second propellants in the correct proportions through
separate manifold assemblies of a single system. There also exists
a need in the art to make a magnetically actuated valve system that
is simpler, lighter and more cost effective.
BRIEF SUMMARY OF THE INVENTION
[0006] To meet the described need, one aspect of the invention
provides a magnetically actuated valve system. The magnetically
actuated valve system comprises a first conduit and a second
conduit. A first sealing structure is moveable in response to a
magnetic force to an open position and spring biased toward a
closed position. The closed position prevents fluid flow through
the first conduit. A second sealing structure is moveable in
response to a magnetic force in a second direction, substantially
opposite to the first direction, to an open position and biased
toward a closed position. The closed position prevents fluid flow
through the second conduit. A magnetic actuator assembly is
constructed and arranged to actuate the first and second sealing
assemblies substantially simultaneously by moving the first and
second sealing structures in the first and second directions,
respectively.
[0007] Other objects, features, and advantages of the present
invention will become apparent form the following detailed
description, the accompanying drawings, and the appended
claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0008] FIG. 1 is a cross section of a magnetically actuated valve
system taken along the line 1-1 of FIG. 3 with the power
removed;
[0009] FIG. 2 is a cross section of the magnetically actuated valve
system similar to FIG. 1, but with the power applied;
[0010] FIG. 3 is a perspective view of the preferred embodiment of
the magnetically actuated valve system embodying the principles of
the present invention;
[0011] FIG. 4 is a perspective exploded view of the magnetically
actuated valve system shown in FIG. 3;
[0012] FIG. 5 is an enlarged perspective view of an S-spring of the
magnetically actuated valve system shown in FIG. 4;
[0013] FIG. 6 is an enlarged cross section similar to FIG. 1
showing an upstream fuel valve and an upstream oxidizer valve with
the power removed;
[0014] FIG. 7 is an enlarged cross section similar to FIG. 6
showing the upstream fuel valve and the upstream oxidizer valve,
but with the power applied;
[0015] FIG. 8 is a farther enlarged cross section of the
magnetically actuated valve system similar to FIG. 6 showing the
upstream fuel valve; and
[0016] FIG. 9 is a further enlarged cross section similar to FIG. 8
showing the downstream fuel valve of the magnetically actuated
valve system;
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring now more particularly to the drawings, FIGS. 1-9
show a preferred embodiment of a magnetically actuated valve system
of the present invention. The magnetically actuated valve system
comprises a first conduit, generally indicated at 10 and a second
conduit generally indicated at 11 for providing fluid flowpaths for
a fuel and an oxidizer, respectively. Fuel conduit 10 is machined
or etched into a fuel manifold assembly, generally indicated at 12,
to provide the fuel flowpath and has sealing structures 28, 30
disposed therein. Oxidizer conduit 11 is machined or etched into an
oxidizer manifold assembly, generally indicated at 14, to provide
the oxidizer flowpath and has sealing structures 36, 38 disposed
therein. Each manifold assembly 12, 14 can be formed in the manner
disclosed in copending U.S. patent application Ser. No. 09/257,186,
the entire disclosure of which is incorporated herein by
reference.
[0018] Magnetic solenoid actuators 48, 50 are disposed within a
magnetic actuator assembly housing structure, generally indicated
at 16. Magnetic solenoid actuator 48 is constructed and arranged to
exert a magnetic force on sealing structures 28, 36 to
substantially simultaneously actuate the same in opposite
directions relative to one another. Magnetic solenoid actuator 50
is constructed and arranged to exert a magnetic force on sealing
structures 30, 38 to substantially simultaneously actuate the same
in opposite directions relative to one another.
[0019] As best illustrated in FIGS. 1 and 2, fuel manifold assembly
12 and oxidizer manifold assembly 14 are of identical construction
and are similarly described hereinbelow. Fuel manifold assembly 12
includes a pair of valve seats 24, 26 machined therein, by standard
machining techniques, diffusion bonding or electron beam welding,
to define an upstream and a downstream fuel valve, respectively.
Valve seats 24, 26 are configured and positioned at inlets 91, 95
of the upstream and the downstream fuel valves, respectively.
Similarly, oxidizer manifold assembly 14 comprises a pair of valve
seats 32, 34 machined therein, by standard machining techniques,
diffusion bonding or electron beam welding, to define an upstream
and a downstream oxidizer valve, respectively. It may also be
preferable to etch valve seats 24, 26 and 32, 34 in fuel and
oxidizer manifold assemblies 12, 14, respectively, as taught in
U.S. patent application Ser. No. 09/257,186, cited earlier herein.
Valve seats 32, 34 are configured and positioned at each inlet 101,
105 of the upstream and downstream oxidizer valves,
respectively.
[0020] As best shown in FIGS. 1-4, magnetic actuator assembly
housing structure 16 comprises a pair of circumferentially
extending magnetic actuator assembly receiving portions 40 integral
with one another. Each circumferentially extending magnetic
actuator assembly receiving portion 40 provides a groove 41 for
carrying a sealing structure 46, with each groove 41 positioned on
the opposite longitudinal ends of each magnetic actuator assembly
receiving portion 40. As best shown in FIGS. 3 and 4, a pair of
generally tubular fastener receiving portions 42 integrally extends
from each magnetic actuator assembly receiving portion 40. Each
fastener receiving portion 42 has one threaded fastener receiving
orifice 44a on one longitudinal end thereof and another threaded
fastener receiving orifice (not shown) on the opposite longitudinal
end thereof. Magnetic actuator assembly housing structure 16
preferably is made of a low magnetic flux capacity material. It may
be preferable to for magnetic actuator housing structure 16 to be
made from aluminum or titanium. Housing structure 16 may be cast,
forged or machined.
[0021] As best shown in FIG. 4, the magnetic actuator assembly
comprises upstream magnetic solenoid actuator 48 and downstream
magnetic solenoid 50. Upstream magnetic solenoid actuator 48 moves
the fuel sealing structure 28 and the oxidizer sealing structure 36
to a power applied, open position. Similarly, downstream magnetic
solenoid 50 moves fuel sealing structure 30 and oxidizer sealing
structure 38 to a power applied, open position. Magnetic solenoid
actuators 48, 50 are installed within magnetic actuator assembly
receiving portions 40 of magnetic actuator assembly housing
structure 16. Upstream and downstream magnetic solenoid actuators
48, 50 comprise solenoid cases 52, each of which generally
surrounds a centrally positioned solenoid core 54. Each solenoid
core 54 extends through a conductive coil 56, for example of
copper, such that each conductive coil 56 is generally surrounded
by solenoid case 52 on their radial exterior. It is contemplated
that the two magnetic solenoid actuators 48, 50 may be operated
independently or coupled electrically in series or parallel to
normally operate substantially simultaneously, as further described
below.
[0022] Isolation caps 58a, 58b, 58c, 58d engage opposite
longitudinal sides of magnetic solenoid actuators 48, 50,
respectively, to retain each magnetic solenoid actuator 48, 50
within one of circumferentially extending magnetic actuator
assembly receiving portions 40 of magnetic actuator assembly
housing structure 16. Isolation caps 58a, 58c are welded to fuel
manifold assembly 12. Isolation caps 58b, 58d are welded to
oxidizer manifold assembly 14. Isolation caps 58a, 58b, 58c, 58d
may be made from titanium or any other low flux capacity material
capable of exposure to the propellants and suitable for being
welded to manifolds 12, 14.
[0023] Fuel sealing structure 28 includes a fuel armature member
64, an S-spring 68 and a sealing portion 72. Fuel sealing structure
30 is disposed downstream from fuel sealing structure 28 and
includes a downstream fuel armature member 66 positioned downstream
from upstream fuel armature member 64, an S-spring 70 and a sealing
portion 74. S-springs 68, 70 bias sealing structures 28, 30 in
closed positions to prevent fuel flow through first conduit 10.
Fuel sealing structures 28, 30 are enclosed within fuel manifold 12
by isolation caps 58a, 58c.
[0024] Similarly, oxidizer sealing structure 36 includes an
oxidizer armature member 76, an S-spring 80 and a sealing portion
84. Oxidizer sealing structure 38 is disposed downstream from
oxidizer sealing structure 36 and includes a downstream oxidizer
armature member 78 positioned downstream from upstream oxidizer
armature member 76, an S-spring 82 and a sealing portion 86.
S-springs 80, 82 bias sealing structures 36, 38 into closed
positions to prevent oxidizer flow through second conduit 11.
Oxidizer sealing structures 36, 38 are enclosed within oxidizer
manifold 14 by isolation caps 58b, 58d.
[0025] It might be preferable for fuel and oxidizer manifold
assemblies 12, 14 to include a plurality of diffusion bonded layers
of sheet material, for example of titanium, having conduits 10, 11
etched therein to provide passageways for fuel and oxidizer
respectively in the manner disclosed in copending U.S. patent
application Ser. No. 09/257,186.
[0026] Various fuels and oxidizers could be used within fuel and
oxidizer manifold assemblies 12, 14; however, the preferred fuel
used in fuel manifold assembly 12 is monomethylhydrazine (MMH) and
the preferred oxidizer used in oxidizer manifold assembly 14 is
nitrogen tetroxide (N.sub.2O.sub.4). The fuel may flow through fuel
manifold assembly 12 and oxidizer may flow through oxidizer
manifold assembly 14 in a liquid or gaseous state.
[0027] FIG. 5 is an enlarged perspective view showing S-spring 68,
but could be representative of any other S-spring 70, 80 or 82.
S-springs 68, 70, 80 and 82 are preferably flat discs having
interior walls 69 defining serpentine slots therein. The interior
walls 69 are circumferentially positioned around S-springs 68, 70,
80 and 82 in interposing relation between an inner section 71 of
each S-spring 68, 70, 80 and 82 and an outer rim 73 of the same
S-spring 68, 70, 80 and 82. It may be preferable for S-springs 68,
70, 80 and 82 to be made from ductile, high strength materials with
low magnetic flux capacity such as 316L CRES, or 17-4 PH CRES. It
is contemplated that disc springs, leaf springs or other spring
members may be capable of biasing sealing members 28, 30, 36, 38
against valve seats 24, 26, 32, 34, respectively. The deflection
and preload force of S-springs 68, 70, 80 and 82 is permanently set
by the thickness of spacing shim stack 88a. Shim stack 88b is used
to adjust isolation caps 58a, 58c and 58b, 58d to a position flush
with manifold assembly 12, 14, respectively.
[0028] As best shown in FIGS. 1-3 and 6-9, fuel manifold assembly
12 and oxidizer manifold assembly 14 further comprise an inlet 90a,
90b, a main body portion 92a, 92b and a thruster interface port
94a, 94b, respectively. Inlet 90a, which is preferably tubular or a
thread fitting, extends integrally and is welded to main body
portion 92a. Likewise, inlet 90b, which is preferably tubular or a
thread fitting, extends integrally and is welded to main body
portion 92b. Inlets 90a, 90b are preferably made from titanium, but
could be any other suitable low flux capacity material for
maintaining fuel and oxidizer in separate flowpaths. Inlets 90a,
90b have an etched disc, diffusion buffed or similar inlet filter
96a, 96b and an inlet plug 97a, 97b, respectively, installed
therein. As best shown in FIGS. 1, 2, 6 and 7, inlet plug 97a is
welded within conduit 10 between inlet 91 and outlet 93 of the
upstream fuel valve. Similarly, inlet plug 97b is welded within
conduit 11 between inlet 101 and outlet 103 of the upstream
oxidizer valve.
[0029] Main body portion 92a of fuel manifold assembly 12 has
conduit 10 etched or machined therein and main body portion 92b of
oxidizer manifold assembly 14 has conduit 11 etched or machined
therein.
[0030] Referring back to FIGS. 3 and 4, a pair of circumferentially
raised walls 98a, 98b integrally extends from each main body
portion 92a, 92b and may have edges spaced from one another, as
best shown for the pair of raised walls 98b in FIG. 4. Each pair of
raised walls 98a, 98b defines armature receiving spaces, of which
only spaces 99b are shown in FIG. 4. Raised walls 98a, 98b could be
separate from main body portions 92a, 92b, respectively, and
positioned in abutting relation thereto to define armature
receiving spaces 99a, 99b, respectively. A pair of fastener
receiving openings 100a, 100b integrally extends from opposite
sides of main body portions 92a, 92b, respectively. A pair of
mounting openings 104a and 104b passes through main body portions
92a, 92b on opposite sides of respective thruster interface ports
94a, 94b for mounting fuel and oxidizer manifold assemblies 12, 14
to the thruster. Thruster interface ports 94a, 94b are disposed on
the opposite longitudinal ends of each manifold assembly 12, 14
from respective inlets 90a, 90b.
[0031] Upstream and downstream fuel armature members 64, 66 and
upstream and downstream oxidizer armature members 76, 78 are
preferably flat discs made from high flux capacity material that is
compatible with the propellants such as corrosion resistant steel
(CRES), for example of XM-27 CRES, and are resistance welded to
S-spring 68, 70, respectively. When inner sections 71 of S-springs
68, 70 are joined to upstream and downstream fuel armature members
64, 66, respectively, sealing portions 72, 74 are captured
therebetween such that sealing portions 72, 74 extend through
center opening 75 of S-springs 68, 70, respectively. Sealing
portions 72, 74 may be made from polytetrafluoroethylene (PTFE) or
any other suitable material for circumferentially sealing against
valve seats 24, 26, respectively, to seal the upstream and
downstream fuel valves, respectively.
[0032] Similarly, upstream and downstream oxidizer armature members
76, 78 are made from high flux capacity material that is compatible
with the propellants such as corrosion resistant steel (CRES), for
example of XM-27 CRES, and are resistance welded to S-spring 80,
82, respectively. When the inner sections 71 of S-springs 80, 82
are joined to upstream and downstream oxidizer armature members 76,
78, respectively, sealing portions 84, 86 are captured therebetween
such that sealing portions 84, 86 extend through center opening 75
of S-springs 80, 82. Sealing portions 84, 86 may be made from
polytetrafluoroethylene (PTFE) or any other suitable material for
circumferentially sealing against valve seats 32, 34, respectively
to seal the upstream and downstream oxidizer valves,
respectively.
[0033] Upstream and downstream fuel armature members 64, 66 are
installed within the armature receiving spaces defined by
circumferentially raised walls 98a extending from fuel manifold
assembly 12. Sealing portions 72, 74 contact valve seats 24, 26,
respectively, of fuel manifold assembly 12. As isolation caps 58a,
58b are installed, the outer rim of each S-spring 68, 70 is
deflected developing a preload on sealing portions 72, 74 against
valve seats 24, 26, respectively. Isolation caps 58a, 58c are
welded to fuel manifold assembly 12 to prevent external leakage of
fuel.
[0034] Similarly, upstream and downstream oxidizer armature members
76, 78 are installed within armature receiving spaces 99b defined
by circumferentially raised walls 98b extending from oxidizer
manifold assembly 14. Sealing portions 84, 86 contact valve seats
32, 34, respectively, of oxidizer manifold assembly 12. As
isolation caps 58a, 58b are installed, the outer rim of each
S-spring 80, 82 is deflected developing a preload on sealing
portions 84, 86 against valve seats 32, 34, respectively. Isolation
caps 58b, 58d are welded to oxidizer manifold assembly 14 to
prevent external leakage of oxidizer. FIG. 4 illustrates the
alignment of fastener receiving openings 100a of fuel manifold
assembly 12 with threaded fastener receiving orifices 44a of
fastener receiving portions 42. Similarly, fastener receiving
openings 100b of oxidizer manifold assembly 14 align with the
threaded fastener receiving orifices (not shown) on the opposite
longitudinal end of fastener receiving portions 42. A plurality of
fasteners 106a and 106b are in the form of tie wired cap screws and
have one threaded end thereof. Fasteners 106a extend through
fastener receiving openings 100a and into threaded fastener
receiving orifices 44a to fixedly secure fuel manifold assembly 12
to magnetic actuator assembly housing 16.
[0035] Fasteners 106b extend through fastener receiving openings
100b and into the threaded fastener receiving orifices (not shown)
on the opposite ends as threaded fastener receiving orifices 44a to
fixedly secure oxidizer manifold assembly 14 and magnetic actuator
assembly housing 16 together. It should be noted that in FIGS. 1-9,
oxidizer manifold assembly 14 could be shown mounted above magnetic
actuator assembly housing structure 16 and fuel manifold assembly
12 could be shown mounted below magnetic actuator assembly housing
structure 16.
[0036] After titanium fuel and oxidizer manifold assemblies 12, 14
are attached to magnetic actuator assembly housing 16, magnetic
solenoid actuators 48, 50 are protected from the ambient
environment. Sealing structures 46, preferably in the form of
O-rings, are disposed between manifold assemblies 12, 14 and
magnetic actuator assembly housing structure 16 within each groove
41 to environmentally seal the enclosure, as best shown in FIGS. 1
and 2. It may be preferable for the O-rings to be made from
silicone.
Operation
[0037] The integrity of each seal may be tested by energizing only
one of magnetic solenoid actuators 48, 50 at a time. With one
actuator energized and fluids under pressure supplied to both
inlets 90a and 90b, the integrity of the seals controlled by the
other actuator will be tested. In normal operation, both actuators
are energized in unison.
[0038] Referring to FIGS. 1, 2 and 6-9, the operation of the
magnetically actuated valve system will be fully described below.
The operation of fuel manifold assembly 12 will be described as
fuel flows from inlet 90a through upstream fuel valve 28 and
downstream fuel valve 30 to thruster interface port 94a within fuel
manifold assembly 12. Fuel inlet filter 96a protects the upstream
and downstream fuel valves from impurities or harmful agents that
could deter operation of the upstream and downstream fuel valves.
The passing fuel flows through fuel inlet filter 96a before
reaching inlet 91 for the upstream fuel valve. The upstream fuel
valve controls the fuel flow to inlet 95 for the downstream fuel
valve, which in turn controls fuel flow to thruster interface port
94a.
[0039] Fuel enters fuel manifold assembly 12 through fuel inlet 90a
where inlet plug 97a directs its flow through fuel filter 96a and
into the inlet for the fuel upstream valve. Fuel flows into the
fuel upstream valve through inlet 91, which is in the form of an
opening in fuel manifold assembly 12. Conduit 10 in the main body
portion 92a of fuel manifold assembly 12 connects outlet 93 of the
upstream fuel valve to inlet 95 of the downstream fuel valve. The
downstream fuel valve discharges into the thruster through thruster
interface port 94a. The thruster may be included within a
spacecraft engine, or any other suitable engine in which two fluids
are delivered to combustion chambers.
[0040] Before power is applied to coils 56 of upstream and
downstream actuators 48, 50, S-springs 68, 70 firmly preload
sealing portions 72 and 74 against valve seats 24, 26,
respectively. As described above, the preload is sufficient to
close and seal the upstream and downstream fuel valves against
leakage and to prevent liftoff under worst-case vibration
loading.
[0041] When power is applied to coil 56 of upstream magnetic
solenoid actuator 48, a magnetic flux is generated in a magnetic
circuit consisting of core 54, case 52, and upstream fuel armature
member 64. The magnetic flux in the air gap between each upstream
fuel armature member 64, case 52 and core 54 exerts an attractive
force on upstream fuel armature member 64. This attractive force
overcomes the preload of S-spring 68 causing upstream fuel armature
member 64 to be drawn up against isolation cap 58a lifting sealing
member 72 off valve seat 24. With sealing member 72 lifted off
valve seat 24, fuel is allowed to flow across valve seat 24 to the
inlet for the downstream fuel valve. Upstream armature member 64 is
held in the power applied, open position as long as power is
applied to coil 56 of magnetic solenoid actuator 48.
[0042] When power is applied to coil 56 of downstream actuator 50,
a magnetic flux is generated in a magnetic circuit consisting of
core 54, case 52, and downstream fuel armature member 66. The
magnetic flux in the air gap between downstream fuel armature
member 66, case 52 and core 54 exerts an attractive force on
downstream fuel armature member 66. This attractive force overcomes
the preload of S-spring 70 causing downstream fuel armature member
66 to be drawn up against the isolation cap 58c lifting sealing
member 74 off valve seat 26. With sealing member 74 off valve seat
26, fuel is allowed to flow across valve seat 26 and through
thruster interface port 94a into a thruster combustion portion of
an engine, for example a spacecraft engine. Downstream armature
member 66 is held in the power applied, open position as long as
power is applied to coil 56 of magnetic solenoid actuator 50.
[0043] When the power is removed from coils 56 of upstream and
downstream magnetic solenoid actuators 48, 50, the magnetic fields
collapse, thus reducing the magnetic attracting force on upstream
and downstream fuel armature members 64, 66 to virtually zero.
Without magnetic force to oppose them, S-springs 68, 70 drive
upstream and downstream fuel armature members 64, 66 and the
sealing portions 72 and 74, respectively, to the power removed,
closed position and reapply the preload.
[0044] Because the operation and nature of oxidizer manifold
assembly 14 is basically the same as for fuel manifold assembly 12,
it is therefore unnecessary to repeat details. Fuel and oxidizer
simultaneously flow into and through conduits 10, 11 of fuel and
oxidizer manifold assemblies 12, 14, respectively, so that both
fuel and oxidizer will be maintained in correct proportions therein
and directed into the thruster portion of an engine whereby the
fuel will be ignited.
[0045] Alternatively, a permanent magnet (not shown) could be
inserted into each core 54 so that upstream and downstream
actuators 48, 50 would be the same in construction and operation.
Only the operation of upstream actuator 48 will be described
below.
[0046] A first short electrical pulse is applied to coil 56 of
upstream actuator 48 to generate a magnetic flux in a magnetic
circuit consisting of case 52, core 54 and upstream fuel armature
member 64. The magnetic flux in the air gap between each upstream
fuel armature 64, case 52 and core 54 exerts a larger attractive
force on upstream fuel armature 64 than that of the permanent
magnet. This attractive force overcomes the preload of S-spring 68
causing upstream fuel armature 64 to be drawn up against isolation
cap 58a lifting seat member 72 off valve seat 24. With sealing
member 72 lifted off valve seat 24, fuel is allowed to flow across
valve seat 24 to the inlet for the downstream fuel valve. The
permanent magnet positioned axially within core 54 holds upstream
armature member 64 in the power applied, open position.
[0047] To reduce the magnetic attractive force on upstream armature
member 64, a second short electrical pulse having a reverse
polarity of the first pulse is applied to coil 56 to create a
magnetic flux polarity opposite of the permanent magnet. Reversed
polarity of the electromagnet is preferably achieved by using a
reversed polarity electric pulse or by providing a second coil
along the same axis as coil 54 but with an opposite winding
direction. Then, S-spring 68 would drive upstream fuel armature
member 64 and sealing portion 72, respectively, to the power
removed, closed position and reapply the preload. The air gap
between each upstream fuel armature member 64, case 52 and core 54,
permanent magnet strength and spring constant of S-spring 68 are
selected so that the permanent magnet is insufficiently powerful to
exert an attractive force able to overcome the preload of S-spring
68 when in the closed position.
[0048] While the principles of the invention have been made clear
in the illustrative embodiments set forth above, it will be
apparent to those skilled in the art that various modifications may
be made to the structure, arrangement, proportion, elements,
materials, and components used in the practice of the
invention.
[0049] It will thus be seen that the objects of this invention have
been fully and effectively accomplished. It will be realized,
however, that the foregoing preferred specific embodiments have
been shown and described for the purpose of illustrating the
functional and structural principles of this invention and are
subject to change without departure from such principles.
Therefore, this invention includes all modifications encompassed
within the spirit and scope of the following claims.
* * * * *