Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF INVENTION
Shaft Seal Assembly
CROSS REFERENCE TO RELATED APPLICATIONS
This patent application claims priority from provisional U.S. Pat. App. No.
61/884,880 filed
on 09/30/2013, this patent application also claims priority from non-
provisional U.S. Pat.
App. No. 14/500,003 filed on 09/29/2014, all of which are incorporated by
reference herein
in their entireties.
FIELD OF THE INVENTION
The present invention relates to a shaft seal assembly with multiple
embodiments. In certain
embodiments, the shaft seal assembly may be used as a product seal between a
product vessel
and a shaft therein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR
DEVELOPMENT
No federal funds were used to create or develop the invention herein.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM
LISTING COMPACT DISK APPENDIX
N/A
1
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BRIEF DESCRIPTION OF THE DRAWINGS
In order that the advantages of the invention will be readily understood, a
more particular
description of the invention briefly described above will be rendered by
reference to specific
embodiments illustrated in the appended drawings. Understanding that these
drawings depict
only typical embodiments of the invention and are not therefore to be
considered limited of
its scope, the invention will be described and explained with additional
specificity and detail
through the use of the accompanying drawings.
FIG. 1 is a perspective exterior view of the shaft seal assembly.
FIG. 2 is an exterior end view of the shaft seal assembly with the shaft
element aligned.
FIG. 3 is a sectional view of a first embodiment of the shaft seal assembly,
as shown in FIG.
2 and mounted to a housing.
FIG. 3A illustrates the first surface seal-shaft integrity during angular and
radial shaft
alignment.
FIG. 3B illustrates second surface seal-shaft integrity during angular and
radial shaft
alignment.
FIG. 4 is an exterior end view with the shaft misaligned.
FIG. 5 is a sectional view of the first embodiment as shown in FIG. 3 with
both angular and
radial misalignment of the shaft applied.
FIG. 5A illustrates first seal-shaft integrity allowed by articulation during
angular and radial
shaft misalignment.
FIG. 5B illustrates second seal-shaft integrity allowed by articulation during
angular and
radial shaft misalignment.
FIG. 6 is a sectional view of a second embodiment of the shaft seal assembly
as shown in
FIG. 2.
FIG. 7 is a sectional view of a third embodiment as shown in FIG. 2.
FIG. 8 is a perspective view of a fourth embodiment as mounted to a vessel
wall.
FIG. 9 is a cross-sectional view of a first embodiment of the pressure
balanced shaft seal
assembly mounted to a housing wherein the shaft is in alignment.
FIG. 9A is a detailed view of the portion of the first embodiment of the
pressure balanced
shaft seal assembly adjacent the vent wherein the shaft is in alignment.
FIG. 9B is a detailed view of the portion of first embodiment of the pressure
balanced shaft
seal assembly adjacent the fluid return pathway wherein the shaft is in
alignment.
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FIG. 10 is a cross-sectional view of the first embodiment of the pressure
balanced shaft seal
assembly shown during shaft misalignment.
FIG. 10A is a detailed view of the portion of the first embodiment of the
pressure balanced
shaft seal assembly adjacent the vent wherein the shaft is misaligned.
FIG. 10B is a detailed view of the portion of the first embodiment of the
pressure balanced
shaft seal assembly adjacent the fluid return pathway wherein the shaft is
misaligned.
FIG. 11 is a cross-sectional view of a second embodiment of the pressure
balanced shaft seal
assembly wherein the shaft is in alignment.
FIG. 12 is a cross-sectional view of a third embodiment of the pressure
balanced shaft seal
assembly wherein the shaft is in alignment.
FIG. 13 is a cross-sectional view of another embodiment of a bearing isolator
(or shaft seal
assembly) configured with a rotor.
FIG. 14 is a cross-sectional view of a portion of yet another embodiment of a
bearing isolator
(or shaft seal assembly) configured with a rotor.
FIG. 14A is a cross-sectional view of the portion of the embodiment of a
bearing isolator
shown in FIG. 14 with the shaft misaligned and/or radially displaced.
FIG. 15 is a partial cross-sectional view of the embodiment of a bearing
isolator shown in
FIG. 13 wherein the shaft is misaligned and/or radially displaced.
FIG. 15A is a detailed view of a portion of the embodiment bearing isolator
shown in FIG.
15.
FIG. 16A is an exterior face view of an illustrative embodiment of a multi-
hole shaft seal
assembly, wherein certain hidden surfaces are shown with broken lines.
FIG. 16B is a cross-sectional view of the embodiment of a multi-hole shaft
seal assembly
shown in FIG. 16A along line A-A.
FIG. 17A is an exterior face view of one embodiment of a sealing member that
may be used
with various embodiments of a multi-hole shaft seal assembly.
FIG. 17B is a cross-sectional view of the embodiment of a sealing member shown
in FIG.
17A along line K-K.
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DETAILED DESCRIPTION¨ELEMENT LISTING (FIGS. 1-12)
Description Element No.
Shaft 1
Fixed stator 2
Fixed stator (part-line) 2a
Labyrinth seal 3
Radiused face 3a
Floating stator 4
Fluid return pathway 5
Shaft seal clearance 6
First o-ring 7
Anti-rotation pin 8
Vent 9
Anti-rotation groove (floating stator) 10
Spherical interface 11
Anti-rotation pin 12
Second o-ring 13
Labyrinth seal pattern grooves 14
First o-ring channel 15
Cavity for anti-rotation device (fixed stator) 16
Axial face of labyrinth seal 17
Axial face of floating stator 18
Second o-ring channel 19
First clearance between floating stator/fixed stator 20
Second clearance between floating stator/fixed stator 21
Throttle groove 22
Labyrinth pattern annular groove 23
Sleeve 24
Shaft seal assembly 25
Throttle (alignment skate) 26
Floating stator annular groove 27
Labyrinth seal passage 28
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Floating stator passage 29
Housing 30
Angle of misalignment 31
Bearings and bearing cavity 32
Mounting bolts 33
Vessel wall 34
Pressure balanced shaft seal assembly 40
Labyrinth seal interior face 42
Floating stator interior face 44
Pressure balancing annular channel 46
First radial interface 47a
Second radial interface 47b
Fixed stator annular groove 48
Annular groove radial-interior surface 48a
DETAILED DESCRIPTION
Before the various embodiments of the present invention are explained in
detail, it is to be
understood that the invention is not limited in its application to the details
of construction and
the arrangements of components set forth in the following description or
illustrated in the
drawings. The invention is capable of other embodiments and of being practiced
or of being
carried out in various ways. Also, it is to be understood that phraseology and
terminology
used herein with reference to device or element orientation (such as, for
example, terms like
"front", "back", "up", "down", "top", "bottom", and the like) are only used to
simplify
description of the present invention, and do not alone indicate or imply that
the device or
element referred to must have a particular orientation. In addition, terms
such as "first",
"second", and "third" are used herein and in the appended claims for purposes
of description
and are not intended to indicate or imply relative importance or significance.
Furthermore,
any dimensions recited or called out herein are for exemplary purposes only
and are not
meant to limit the scope of the present disclosure in any way unless so
recited in the claims.
Figures 1-5 provide various views of a first illustrative embodiment of the
shaft seal
assembly 25 that allows for sealing various lubricating solutions within
bearing housing 30
and/or preventing ingress of contaminants to the housing 30, which may be
configured as a
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bearing housing. Figures 6 and 7 provide alternative illustrative embodiments
of the shaft seal
assembly 25 wherein sealing fluids are used. Applicant herein defines sealing
fluids to
include at least both liquids and vapors. Applicant considers air, nitrogen,
water and steam as
well as any other fluid that may work with the proposed shaft seal assembly to
provide a
pressurized fluid barrier for any and all embodiments disclosed herein to be
within the
purview of the present disclosure. The gas or fluid chosen may be based at
least upon process
suitability with the product to be sealed.
Figure 1 is a perspective exterior view of the first illustrative embodiment
of a shaft seal
assembly 25 arranged and engaged with a shaft 1 inserted through the fixed
stator 2 of shaft
seal assembly 25. Figure 2 is an exterior end view of the shaft seal assembly
with shaft 1
aligned within the shaft seal assembly 25.
Figure 3 is a sectional view of a first embodiment of the shaft seal assembly
25 shown in
FIG. 2 illustrating that the shaft seal assembly 25 may be configured as a
labyrinth seal for
retaining lubrication solution within the bearing cavity 32 of housing 30
and/or preventing
ingress of contaminants into the housing 30. The shaft 1 shown in FIG. 3 may
experience
radial, angular or axial movement relative to the fixed stator 2 or a portion
thereof at various
times. The fixed stator 2 of the shaft seal assembly 25 may be engaged with a
housing 30 via
any suitable method and/or structure, including but not limited to flange-
mounted or press-fit.
The shaft seal assembly 25 may also be used in applications with a rotating
housing and
stationary shaft. (Not shown) As required by the particular application of the
shaft 1 and/or
shaft seal assembly 25, the shaft 1 may be allowed to move freely in the axial
direction in
relation to the shaft seal assembly 25.
A labyrinth seal 3 having an interior surface may be positioned adjacent shaft
1. A defined
clearance 6 may exist between the interior surface of said labyrinth seal 3
and the shaft 1. A
radiused surface 3a may be configured such that it is opposite the interior
surface of the
labyrinth seal 3. The radiused surface 3a of the labyrinth seal 3 and the
interior of the floating
stator 4 may be configured to form a spherical interface 11. 0-ring channels
15 and o-rings 7
may be disposed to cooperate with the radiused surface 3a of the labyrinth
seal 3 to seal (or
trap) fluid migration through, between and along engaged labyrinth seal 3 and
floating stator
4 while maintaining a spherical interface 11, which spherical interface 11 may
allow limited
relative rotational movement (articulation) between labyrinth seal 3 and
floating stator 4.
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0-ring channels 15, as shown, may be machined into the floating stator 4 and
may be
positioned at the spherical interface 11 with labyrinth seal 3. 0-ring
channels 15 may be
configured such that they are annular and continuous in relation to labyrinth
seal 3. The o-
ring channel 15 and o-ring 7 may also be placed in the labyrinth seal 3
adjacent the spherical
interface 11. In certain embodiments, o-rings 7 may be constructed of
materials that are
compatible with both the product to be sealed and the preferred sealing fluid.
0-ring channels
15 and o-rings 7 are but one possible combination of structures that may be
used to seal
various potions within the shaft seal assembly 25. Any other structures and/or
method
suitable for the particular embodiment of a shaft seal assembly 25 may be used
without
limitation.
Strategically placed anti-rotation pin(s) 12 may be inserted into anti-
rotation grooves 10 and
may serve to limit relative rotational movement between labyrinth seal 3 and
floating stator 4.
A plurality of anti-rotation grooves 10 and pins 12 may be placed around the
radius of the
shaft 1. If the shaft seal assembly 25 is used in combination with a sealing
fluid, strategic
anti-rotation pins 12 may be removed allowing corresponding anti-rotation
grooves 10 to
serve as a fluid passage through vent 9 and lubricant return 5, one
illustrative embodiment of
which is shown in FIG. 7. Additionally, the relationship of the diameters of
anti-rotation pins
12 and anti-rotation grooves 10 may be selected to allow more or less angular
misalignment
of the shaft 1, respectively. For example, a relatively small-diameter anti-
rotation pin 12 used
with a large-diameter anti-rotation groove 10 would allow for greater relative
movement of
the labyrinth seal 3 in relation to the floating stator 4 in response to
angular misalignment of
shaft 1. A labyrinth seal 3 is one possible embodiment of a sealing structure
that may be used
adjacent to the shaft 1 within the shaft seal assembly 25. However, other
structures and/or
methods may be used to achieve similar functionality without limitation.
An annular channel may be formed within fixed stator 2 and may be defined by
clearance 20
and 21 as allowed between the exterior of said floating stator 4 and the
interior of the fixed
stator 2 of shaft seal assembly 25. The annular channel of fixed stator 2 is
highlighted as A-
A' in FIG. 2. The annular channel of the fixed stator 2 may be formed with
interior surfaces
that are configured such that they are substantially perpendicular to said
shaft 1. The exterior
surfaces of the floating stator 4, which may be substantially encompassed
within the annular
channel of the fixed stator 2, may cooperatively engage with the first and
second interior
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perpendicular faces of the fixed stator 2. An inner interface may be formed by
the first (shaft
seal assembly 25 inboard side) perpendicular annular channel surface of the
fixed stator 2
engaging with the first (inboard side) perpendicular face of the floating
stator 4. An outer
interface may be formed by the second (shaft seal assembly 25 outboard side)
perpendicular
annular interior channel surface of the fixed stator 2 engaging with the
second (outboard side)
perpendicular face of the floating stator 4. 0-ring channels 19 and o-rings 13
may be
disposed therein and may cooperate with the surfaces of floating stator 4 that
are in
perpendicular to relation to shaft 1. These o-rings 13 may function to seal
(or trap) fluid
migration between and along engaged floating stator 4 while allowing limited
relative
rotational movement between floating stator 4 and fixed stator 2. Floating
stator 4 and fixed
stator 2 are one possible embodiment of cooperatively engaged portions of a
shaft seal
assembly 25 that may be configured to allow relative motion between the
portions in at least
one dimension, and which may be used in combination with labyrinth seal 3
within the shaft
seal assembly 25. However, other structures and/or methods may be used to
achieve similar
functionality without limitation.
0-ring channels 19 may be configured such that they are annular and continuous
in relation
to shaft 1. In an embodiment not shown herein, the o-ring channels 19 and o-
rings 13 may be
placed in the body of the floating stator 4 rather than the fixed stator 2. It
is contemplated that
for many applications it may be optimal to place those o-ring channels 19 and
corresponding
o-rings 13 in similar proximal relation. In certain embodiments, o-rings 7 may
be constructed
of materials that are compatible with both the product to be sealed and the
preferred sealing
fluid. 0-ring channels 15 and o-rings 7 are but one possible combination of
structures that
may be used to seal various potions within the shaft seal assembly 25. Any
other structures
and/or method suitable for the particular embodiment of a shaft seal assembly
25 may be
used without limitation.
Strategically placed anti-rotation pin(s) 8 may be inserted into anti-rotation
groove(s) 16 and
may serve to limit both relative radial and rotational movement between
floating stator 4 and
interior side of fixed stator 2. A plurality of anti-rotation grooves 16 and
pins 8 may be placed
around the radius of the shaft 1. The relationship of the diameters of anti-
rotation pins 8 and
anti-rotation grooves 16 may also be selected to allow more or less angular
misalignment of
the shaft. For example, a small-diameter anti-rotation pin 8 and large-
diameter fixed stator
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anti-rotation groove may allow for greater relative movement of the labyrinth
seal 3 in
response to angular misalignment of shaft 1.
The labyrinth pattern seal grooves 14 may be pressure equalized by venting
through one or
more vents 9. If so desired, the vents 9 may be supplied with a pressurized
sealing fluid such
that the sealing fluid over-pressurizes the labyrinth area 14 and shaft seal
clearance 6 to
increase the efficacy of shaft seal assembly 25. A spherical interface 11
between the labyrinth
seal 3 and the floating stator 4 may be configured to allow for angular
misalignment between
the shaft 1 and fixed stator 2. 0-ring channels 19 are annular with the shaft
1 and, as shown,
may be machined into the fixed stator 2 and positioned at the interface
between the fixed
stator 2 and floating stator 4. 0-ring channel 19 may also be placed in the
floating stator 4
and may be engaged with o-rings 13, which may be configured to provide sealing
contact
with the fixed stator 2.
Figure 3A illustrates seal-shaft integrity during angular and radial shaft 1
alignment. This
view highlights the alignment of the axial face 17 of the labyrinth seal 3 and
the axial face 18
of the floating stator 4. Particular focus is drawn to the alignment of the
axial faces 17, 18 at
the spherical interface 11 between the floating stator 4 and labyrinth 3.
Figure 3B illustrates
the shaft-seal integrity during angular and radial shaft 1 alignment at the
surface opposite that
shown in Figure 3A. This view highlights the alignment of the axial faces 17,
18 of labyrinth
seal 3 and floating stator 4, respectively, for the opposite portion of the
shaft seal assembly 25
as shown in FIG. 3A. Those of ordinary skill in the art will appreciate that
because the shaft 1
and the illustrative embodiments of a shaft seal assembly 25 are of a circular
shape and
nature, the surfaces are shown 360 degrees around shaft 1. Again, particular
focus is drawn to
the alignment of the axial faces 17, 18 at the spherical interface 11 between
the labyrinth seal
3 and floating stator 4. Figures 3A and 3B also illustrate the first defined
clearance 20
between the floating stator 4 and the fixed stator 2 and the second defined
clearance 21
between the floating stator 4 and fixed stator 2 and opposite the first
defined clearance 20.
In Figures 2, 3, 3A and 3B, the shaft 1 is not experiencing radial, angular or
axial movement
with respect to a housing 30. Accordingly, in the illustrative embodiments the
width of the
defined clearances 20 and 21, which may be substantially equal, may indicate
little
movement or misalignment upon the floating stator 4.
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Figure 4 is an exterior end view of the shaft seal assembly 25 with the
rotatable shaft 1
misaligned therein. Figure 5 is a sectional view of the first embodiment of
the shaft seal
assembly 25 as shown in FIG. 3 with both angular and radial misalignment of
the shaft 1
applied. The shaft 1 as shown in FIG. 5 is also of the type that may
experience radial, angular
or axial movement relative to the fixed stator 2 (and/or housing 30) of the
shaft seal assembly
25.
As shown at FIG. 5, the defined radial clearance 6 of labyrinth seal 3 with
shaft 1 may be
maintained even though the angle of shaft misalignment 31 has changed. The
shaft 1 still may
be allowed to move freely in the axial direction even though the angle of
shaft misalignment
31 has changed. The arrangement of the shaft seal assembly 25 may allow the
labyrinth seal 3
to move with the floating stator 4 upon introduction of radial movement of
said shaft 1.
The labyrinth seal 3 and floating stator 4 may be secured together by one or
more compressed
o-rings 7 or any other suitable structure and/or method. Rotation of the
labyrinth seal 3 within
the floating stator 4 may be prevented by anti-rotation members, which may
include but are
not limited to screws, anti-rotation pins 8, or similar devices to inhibit
rotation. The pins as
shown in FIGS. 3, 3A, 3B, 5, 6 and 7 are one structure for preventing rotation
of the labyrinth
seal 3 and floating stator 4. However, any other suitable structure and/or
method may be used
to achieve similar results without limitation.
Lubricant, sealing fluid, or other media may be collected and drained through
a series of one
or more optional drains or lubricant return pathways 5. The labyrinth seal 3
may be pressure-
equalized by venting through one or more vents 9. If so desired, the vents 9
may be supplied
with pressurized air or other gas or fluid media to over-pressurize the
labyrinth seal 3 to
increase seal efficacy. The combination of close tolerances between the
cooperatively
engaged mechanical portions of the shaft seal assembly 25 and pressurized
sealing fluid may
inhibit both product and contaminant contact with the internals of the shaft
seal assembly 25.
The spherical interface 11 between the labyrinth seal 3 and the floating
stator 4 may be
configured to allow for angular misalignment between the shaft 1 and fixed
stator 2. 0-ring
channel 19 and o-ring 13, which may be disposed therein, may cooperate with
the opposing
faces of the floating stator 4, which may be configured such that they are
substantially in
perpendicular relation to the rotational axis of the shaft 1. In this manner,
the o-rings 13 may
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cooperate with the floating stator 4 to seal (or trap) fluid migration between
and along the
floating stator 4 while allowing relative radial movement between stator 4 and
fixed stator 2.
Figure 5A illustrates seal-shaft integrity allowed by the shaft seal assembly
25 during angular
and radial shaft 1 misalignment. This view highlights the offset or
articulation of the axial
faces 17 of the labyrinth seal 3 may have in relation the axial faces 18 of
the floating stator 4
for a first portion of the shaft seal assembly 25. Particular focus is drawn
to the offset of the
axial faces 17, 18 at the spherical interface 11 between labyrinth seal 3 and
floating stator 4.
Figure 5B illustrates seal-shaft integrity for a second surface, opposite the
first surface shown
in Figure 5A, during angular and radial shaft misalignment. This view
highlights that during
misalignment of shaft 1, axial faces 17, 18, of the labyrinth seal 3 and
floating stator 4,
respectively, may not be aligned but instead move (articulate) in relation to
each other. The
shaft-to-seal clearance 6 may be maintained in response to the shaft 1
misalignment and the
overall seal integrity may not be compromised because the seal integrity of
the floating stator
4 to fixed stator 2 and the floating stator 4 to labyrinth seal 3 may be
maintained during shaft
1 misalignment. Those of ordinary skill in the art will appreciate that
because the shaft 1 and
shaft seal assembly 25 may be circular in shape and nature, the surfaces are
shown 360
degrees around shaft 1. Figures 5A and 5B also illustrate the first clearance
or gap 20
between the floating stator 4 and the fixed stator 2 and the second clearance
or gap 21
between the floating stator 4 and fixed stator 2 and opposite the first
clearance or gap 20
during relative movement (other than rotational) between the shaft 1 and the
housing 30.
In Figures 4, 5, 5A and 5B, the shaft 1 is experiencing radial, angular, or
axial movement
during rotation of the shaft 1 and the width of the gaps or clearances 20, 21
are shown as
having changed in response to that movement as compared to the gaps or
clearances 20, 21
depicted in FIGS. 3, 3A and 3B. The change in dimensions of clearance 20, 21
indicate the
floating stator 4 may move in response to the movement or angular misalignment
of shaft 1.
The shaft seal assembly 25 may allow articulation between axial faces 17, 18,
maintenance of
spherical interface 11 and radial movement at first and second clearance, 20,
21, respectively,
while maintaining shaft seal clearance 6.
Figure 6 is a sectional view of a second embodiment of the shaft seal assembly
25 as shown
in FIG. 2 for over-pressurization with alternative labyrinth seal pattern
grooves 14. In this
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embodiment, the labyrinth seal pattern grooves 14 may be comprised of a
friction-reducing
substance such as polytetrafluoroethylene (PTFE), wherein the friction-
reducing substance
may be configured such that it forms a close clearance to the shaft 1. PTFE is
also sometimes
referred to as Teflon , which is manufactured and marketed by Dupont. PTFE is
a plastic
with high chemical resistance, low and high temperature capability, resistance
to weathering,
low friction, electrical and thermal insulation, and high lubricity. Carbon or
any other
materials without limitation may be substituted for PTFE to provide the
necessary sealing
qualities and lubricous qualities for labyrinth seal pattern grooves 14.
Pressurized sealing fluids may be supplied to over-pressurize the lubricious
labyrinth pattern
26 as shown in FIG. 6. The pressurized sealing fluids may be introduced to the
annular
groove 23 of the throttle 26 through one or more inlets. Throttle 26 may also
be referred to as
"an alignment skate" by those of ordinary skill in the art. Throttle 26 may
allow the labyrinth
seal 3 to respond to movement of the shaft 1 caused by the misalignment of the
shaft 1. The
pressurized sealing fluid may pass through the close clearance formed between
the shaft 1
and labyrinth seal 3 having throttle 26. The close proximity of the throttle
26 to the shaft 1
also may create resistance to the sealing fluid flow over the shaft 1 and may
cause pressure to
build up inside the annular groove 23. Floating annular groove 27 in
cooperation and
connection with annular groove 23 also may provide an outlet for excess
sealing fluid to be
bled out of shaft seal assembly 25 for pressure equalization or to maintain a
continuous fluid
purge on the shaft sealing assembly 25 during operation. An advantage afforded
by this
aspect of the shaft sealing assembly 25 is its application wherein "clean-in
place" product-
seal decontamination procedures are preferred or required. Examples would
include food
grade applications.
Figure 7 illustrates shaft seal assembly 25 with the anti-rotation pin 12
removed to improve
visualization of the inlets. These would typically be comprised of, but are
not limited to, a
series of ports, inlets or passages about the circumference of the shaft seal
assembly 25.
Figure 7 also illustrates that the shape and pattern of the labyrinth seal 3
may be varied from
one embodiment of the shaft seal assembly 25 to the next. The shape of
throttles 26 may also
be varied as shown by the square profile shown at throttle groove 22 in
addition to the
circular-type 26. Also note that where direct contact with the shaft 1 is not
desired, the shaft
seal assembly 25 may be used in combination with a separate sleeve 24 that
would be
attached by varied means to the shaft 1.
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Figure 8 shows that another embodiment of the shaft seal assembly 25 wherein
the shaft seal
assembly 25 has been affixed to a vessel wall 34. The shaft seal assembly 25
may be affixed
to vessel wall 34 through securement members (e.g., including but not limited
to mounting
bolts 33) to ensure improved sealing wherein shaft 1 is subjected to angular
misalignment.
The mounting bolts 33 and slots (not numbered) through the shaft seal assembly
25 exterior
are one structure and method of mounting the shaft seal assembly 25 to a
housing 30.
However, any suitable structure and/or method may be used without limitation.
In certain applications, especially those wherein the process side of shaft
seal assembly 25
(generally the area to the left of the shaft seal assembly 25 as shown in
FIGS. 3-3B and 5-7)
is at an increased pressure, it is desirable for the shaft seal assembly 25 to
be configured to
balance the pressure experienced by the shaft seal assembly 25 in the axial
direction. A
pressure balanced shaft seal assembly 40 that balances the pressure (in the
axial direction)
that the product applies to the labyrinth seal interior face 42 and floating
stator interior face
44 is shown in FIGS. 9-12.
In the first embodiment of the pressure balanced shaft seal assembly as shown
in FIGS. 9-
10B, the shaft sealing member (i.e., the labyrinth seal 3 in combination with
the floating
stator 4) includes a pressure balancing annular channel 46. Save for the
pressure balancing
annular channel 46, the pressure balanced shaft seal assembly 40 may operate
in generally the
same manner as the shaft seal assembly 25 shown in FIGS. 1-8 and described in
detail above.
That is, the floating stator 4 may be positioned in the fixed stator annular
groove 48. The first
clearance between floating stator/fixed stator 20, which in the embodiments
pictured herein
may be between the floating stator radial-exterior surface 45 and the annular
groove radial-
interior surface 48a (shown in FIGS. 9A and 9B), may account at least for
radial
perturbations of the shaft 1 with respect to the housing 30. The spherical
interface 11 between
the floating stator 4 and the labyrinth seal 3 may account at least for
angular perturbations of
the shaft 1 with respect to the housing 30.
The pressure balancing annular channel 46 may be formed in the floating stator
4 adjacent the
first radial interface 47a between the floating stator 4 and the fixed stator
2, as shown in
FIGS. 9-10 for the first embodiment. As shown in the various embodiments
pictured herein,
the first radial interface 47a between the floating stator 4 and the fixed
stator 2 may be
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adjacent the portion of the fixed stator 2 fashioned with the cavity for anti-
rotation device 16.
That is, the axial face of the floating stator 4 that is positioned within the
fixed stator 2 and
furthest from the process side of the pressure balanced shaft seal assembly
40. A second
radial interface 47b between the floating stator 4 and fixed stator 2, which
may be
substantially parallel to the first radial interface 47a, may be positioned
closer to the process
side of the pressure balanced shaft seal assembly 40 as compared to the first
radial interface
47a.
In many applications the optimal radial dimension of the pressure balancing
annular channel
46 may be substantially similar to the radial dimension of the floating stator
interior face 44
so that the area of the floating stator 4 acted upon by the product and the
area of the floating
stator 4 acted upon by the sealing fluid may have relatively equal surface
areas. In such a
configuration, the axial forces may generally balance if the product and the
sealing fluid are
pressurized to approximately the same value. Accordingly, the optimal radial
dimension of
the pressure balancing annular channel 46 may depend on the design
characteristics of the
entire system, and the radial dimension of the pressure balancing annular
channel 46 may be
any suitable amount for a particular application, whether greater or less than
the radial
dimension of the floating stator interior face 44. The axial dimension of the
pressure
balancing annular channel 46 may also vary depending on the design
characteristics of the
entire system, including but not limited to the specific sealing fluid that is
used, the product
pressure, and the pressure of the sealing fluid. In some applications the
optimal axial
dimension of the pressure balancing annular channel 46 will be 0.005 of an
inch, but may be
greater in other embodiments and less in still other embodiments.
The pressure balancing annular channel 46 may allow sealing fluid introduced
into the first
clearance between floating stator/fixed stator 20 (from where the sealing
fluid may enter the
pressure balancing annular channel 46) to act upon the floating stator 4 in an
axial direction.
Typically, the process side of the pressure balanced shaft seal assembly 40
(generally the area
to the left of the pressure balanced shaft seal assembly 40 as shown in FIGS.
9-12)
experiences forces from the process fluid acting upon the labyrinth seal
interior face 42 and
floating stator interior face 44. These forces are most often due to the
pressure generated by
the rotating equipment to which the shaft 1 is coupled. For example, if the
shaft 1 is coupled
to a fluid pump generating seventy pounds per square inch (psi) of head
pressure, the process
side of the pressure balanced shaft seal assembly 40 may be pressurized to
approximately 70
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psi. This pressurized fluid may act upon the labyrinth seal interior face 42
and floating stator
interior face 44, and consequently urge the labyrinth seal 3 and floating
stator 4 in the axial
direction away from the process side of the pressure balancing shaft seal
assembly 40 (i.e.,
generally to the right side of the drawing as depicted in FIGS. 9-12). By
contrast, sealing
fluid located in the pressure balancing annular channel 46 may urge the
labyrinth seal 3 and
floating stator 4 in the axial direction toward the process side of the
pressure balancing shaft
seal assembly 40, which may substantially cancel the axial force the product
exerts upon the
pressure balancing shaft seal assembly 40, depending on the design of the
sealing fluid
system.
Figures 11 and 12 show a second and third embodiment of the pressure balanced
shaft seal
assembly 40, respectively. The second and third embodiments of the pressure
balanced shaft
seal assembly 40 generally correspond to the second and third embodiments of
the shaft seal
assembly 25 as shown in FIGS. 7 and 8 and described in detail above. However,
as with the
first embodiment of the pressure balanced shaft seal assembly 40 as shown in
FIGS. 9-10B,
the second and third embodiments include a pressure balancing annular channel
46.
The various embodiments of the pressure balanced shaft seal assembly 40
pictured and
described herein may be formed with a fixed stator 2 and floating stator 4
that may be
comprised of two distinct portions. These embodiments may facilitate assembly
of the
pressure balanced shaft seal assembly 40 since in the embodiments pictured
herein the
majority of the floating stator 4 may be positioned within the fixed stator 2.
When installing a
pressure balanced shaft seal assembly 40 according to the first embodiment (as
pictured in
FIGS. 9-10B), the first portion of fixed stator 2 (i.e., the portion adjacent
the process side of
the pressure balanced shaft seal assembly 40) may be affixed to a housing 30.
Next, the
floating stator 4 and labyrinth seal 3 may be positioned as a singular
assembled piece
(wherein the components forming the spherical interface 11 have been
preassembled)
between the shaft 1 and the first portion of the fixed stator 2. The placement
of the floating
stator 4 and labyrinth seal 3 within the fixed stator 3 may forms the second
axial interface
47b between the fixed stator 2 and floating stator 4. Finally, the second
portion of the fixed
stator 2 (i.e., the portion furthest from the process side of the pressure
balanced shaft seal
assembly 40) may be positioned adjacent to and affixed to the first portion of
the fixed stator
2. The positioning of the second portion of the fixed stator 2 subsequently
may form the first
radial interface 47a between the fixed stator 2 and floating stator 4.
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Alternatively, the floating stator 4 and labyrinth seal 3 may be separately
positioned within
the fixed stator annular groove 48. For example, after the first portion of
the fixed stator 2 has
been affixed to the housing 30, the first portion of the floating stator 4 may
be positioned
within the fixed stator annular groove 48. The placement of the first portion
of the floating
stator 4 within the fixed stator annular groove 48 may form the second axial
interface 47b
between the fixed stator 2 and floating stator 4. Next, the labyrinth seal 3
may be positioned
adjacent the shaft 3, the placement of which may form a portion of the
spherical interface 11
between the floating stator 4 and labyrinth seal 3. Next, the second portion
of the floating
stator 4 may be positioned adjacent the first portion of the floating stator 4
and affixed thereto
with a plurality of anti-rotation pins 8, which may complete the spherical
interface 11
between the floating stator 4 and labyrinth seal 3. Finally, the second
portion of the fixed
stator 2 may be affixed to the first portion of the fixed stator 2 with a
plurality of bolts, rivets,
or other fasteners without limitation, the placement of which may form the
first axial
interface 47a between the floating stator 4 and fixed stator 2. Any suitable
securing members
known to those skilled in the art may be used to affix the first and second
portions of the
floating stator 4 to one another or to affix the first and second portions of
the fixed stator 2 to
one another in any embodiments of a shaft seal assembly 25 or pressure
balanced shaft seal
assembly 40 without limitation.
ELEMENT LISTING (FIGS. 13-15A)
Description Element No.
Shaft 10
Bearing isolator 18
Housing 19
Rotor 20
Stator 30,31a
Fixed stator 31
Passage 40, 40a
Spherical surface 50, 51
Clearance 52
Frictional seal 60
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Flange unit 61a
Center point 80
Conduit 99
Fluid 100
Pin 101
Annular recess 102
Figure 13 shows another embodiment of a bearing isolator 18 (or shaft seal
assembly)
mounted adjacent a shaft 10. The shaft 10 may extend through the bearing
isolator 18 and/or
the housing 19. A source of gas or fluid, 100 which may include but is not
limited water, gas,
vapor and/or lubricant, may also be in communication with the bearing isolator
18 via
conduit 99. The rotor 20 may be affixed to the shaft 10 by means by a
frictional seal 60,
which may be configured as one or more o-rings. The rotor 20 may be configured
to follow
the rotational movement of the shaft 10 because of the frictional engagement
of the seals 60.
The passages 40 and 40a may be configured as shown but will not be described
in detail here
because such description is already understood by those of ordinary skill in
the art.
A pair of corresponding spherical surfaces 50 and 51 may be used to create a
self-aligning
radial clearance 52 between the rotor 20 and the stator 30 prior to, during,
and after use. This
clearance 52 may be maintained at a constant value even as the shaft 10
becomes misaligned
during use. Various amounts and direction of misalignment between the
centerline of the
shaft 10 and the housing 19 are illustrated in FIGS. 15-17. An annular recess
102 between
the stator 30 and fixed stator 31 may allow the bearing isolator 18 to
accommodate a
predetermined amount of radial shaft displacement.
In the embodiments shown herein, the spherical surfaces 50, 51 may have a
center point
identical from the axial faces of both the rotor and stator 20, 30,
respectively. However, the
spherical surfaces 50, 51 may be radially, and/or as shown, vertically spaced
apart. These
spherical surfaces 50, 51 may move radially in response to and/or in
connection with and/or
in concert with the radially positioning of other components of the bearing
isolator 18.
Typically, if the shaft 10 becomes misaligned with respect to the housing 19,
the rotor 20
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may consequently become misaligned with respect thereto, and then the
spherical surfaces
50, 51 and/or the stator 30, moving radially within the annular recess of the
fixed stator 31,
may compensate for the misalignment.
Figures 15 and 15A illustrate that in one embodiment of the bearing isolator
18, the rotor 20
may move with respect to the stator 30, 31 as shaft 10 is misaligned with
respect to housing
19 through the interaction between spherical surfaces 50, 51. Such relative
movement to help
to ensure the distances between the center points of the rotor 20 and stator
30 and a fixed
point on the housing 19 are constant or relatively constant during use.
In the embodiment of the bearing isolator 18 shown in FIGS. 14 and 14A, the
spherical
surfaces 50, 51 may be positioned on a fixed stator 31 and stator 31a,
respectively, rather than
on the rotor 20 and stator 30. Still referring to FIGS. 14 and 14A, this
design may allow the
rotor 20 and stator 31a to move with respect to the fixed stator 31, flange
unit 61a, and/or
housing 19. The rotor 20, stator 31a, and fixed stator 31 may move radially
with respect to
the flange unit 61a (and consequently with respect to the housing 19) as best
shown in FIG.
14A. In this embodiment of the bearing isolator 18 there may be a very minimal
amount of
relative rotation between the spherical surfaces 50, 51.
The embodiment of the bearing isolator 18 shown in FIGS. 14 and 14A may
provide for
controlled radial movement of the fixed stator 31, stator 31a, and/or rotor 20
with respect to
flange unit 61a, which flange unit 61a may be engaged with a housing 19.
Rotational
movement of the fixed stator 30 with respect to the flange unit 61a may be
prevented by anti-
rotational pins 101. The fixed stator 31 may be frictionally secured to the
flange unit 61a
using a frictional seal 61, which may be made of any material with sufficient
elasticity and
frictional characteristics to hold the fixed stator 31 in a fixed radial
position with respect to
the flange unit 61a but still be responsive to the radial forces when the
shaft 10 is misaligned.
Changes to the radial position of the fixed stator 31, stator 31a, and/or
rotor 20 and the
resulting positions thereof (as well as the resulting position of the
interface between the fixed
stator 31 and stator 31a) may occur until the radial force is fully
accommodated or until the
maximum radial displacement of the bearing isolator 18 is reached.
Referring now to FIGS. 15 and 15A, in operation the rotor 20 may be moved
radially as the
shaft 10 becomes misaligned with respect to the housing 19. Radial movement of
the
18
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spherical surfaces 50, 51 between the stator 31a and fixed stator 31 may
result from this
pressure. FIG. 15 shows potential resultant radial movement of center point 80
as the shaft 10
is misaligned. During normal operation, the shaft 10 is typically horizontal
with respect to the
orientation shown in FIG. 15, as represented by line A. As the shaft 10
becomes misaligned
in a manner represented by line B, the center point 80 may move to a point
along line A". As
the shaft 10 becomes misaligned in a manner represented by line B', the center
point 80 may
move to a point along line A'. However, in other shaft 10 misalignments, the
radial positions
of the rotor 20, stator 30, and/or fixed stator 31 may be constant and the
spherical surfaces 50,
51 may compensate for the shaft 10 misalignment. From the preceding
description it will be
apparent that the bearing isolator 18 may provide a constant seal around the
shaft 10 because
the distance between the spherical surfaces 50, 51 may be maintained as a
constant regardless
of shaft 10 misalignment of a normal or design nature.
The physical dimensions of the spherical surfaces 50 and 51 may vary in linear
value and in
distance from the center point 80, depending on the specific application of
the bearing
isolator 18. These variations will be utilized to accommodate different sizes
of shafts and
seals and different amounts of misalignment, and therefore in no way limit the
scope of the
bearing isolator 18 as disclosed herein. Additionally, and suitable structure
and/or method for
engaging various elements with one another either rotationally, fixedly, or
with various
degrees of freedom of motion therebetween may be used with the shaft seal
assembly 18
without limitation, including but not limited to screws, bolts, pins, chemical
adhesives,
interference fits, and/or combinations thereof
ELEMENT LISTING (FIGS. 16-17)
Description Element No.
Shaft seal assembly 10
Shaft 12
Fastener 14
Fixed stator 20
Fixed stator seal groove 20a
Main body 21
Face plate 22
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Face plate pin recess 22a
Face plate seal groove 22b
Inlet 24
Annular recess 26
Seal 28
Floating stator 30
Floating stator seal groove 30a
Radial exterior surface 32
First pin recess 33
Pin 34
Second pin recess 35
Second pin recess enlarged portion 35a
Floating stator annular groove 37
Concave surface 38
Sealing member 40
Recess 42
Radial bore 44
Radial bore inlet 44a
Radial bore outlet 44b
Radial interior surface 46
Convex surface 48
Another embodiment of a shaft seal assembly 10 is shown in FIGS. 16A & 16B.
This
embodiment is similar to the embodiment of the shaft seal assembly 25
described above and
shown in FIGS. 1-12. The shaft seal assembly 10 may include a fixed stator 20,
floating
stator 30, and a sealing member 40, as shown. In the pictured embodiment, the
sealing
member 40 may be positioned adjacent a shaft 12 that is rotatable with respect
to the shaft
seal assembly 10 and/or housing. Accordingly, a rotational interface may exist
between a
radial interior surface 46 of the sealing member 40 positioned adjacent the
shaft 12 and an
exterior portion of the shaft 12. In other embodiments of the shaft seal
assembly 10 not
pictured herein, the sealing member 40 may be engaged with the shaft 12 such
that it rotates
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therewith (e.g., the shaft seal assembly 10 may be configured with a rotor).
In such an
embodiment, a rotational interface may exist between a concave surface 38 of
the floating
stator 30 and a convex surface 48 of the sealing member 40. Accordingly, the
scope of the
shaft seal assembly 10 as disclosed herein extends to shaft seal assemblies 10
in which the
sealing member 40 does or does not rotate with a shaft 12.
The embodiment of the shaft seal assembly 10 shown in FIGS. 16A & 16B may
include a
fixed stator 20 that may be securely mounted to a housing (not shown in FIGS.
16A & 16B)
by any suitable methods and/or structure. The fixed stator 20 may include a
main body 21
and a face plate 22 that may be engaged with one another via one or more
fasteners 14. It is
contemplated that a fixed stator 20 formed with a main body 21 and face plate
22 may
facilitate ease of installation of the shaft seal assembly 10 in certain
applications. In such
applications, the main body 21 may be affixed to the housing, the sealing
member 40 and
floating stator 30 may be positioned appropriately, and then the face plate 22
may be secured
to the main body 21. However, the scope of the present disclosure is in no way
limited by the
specific mounting and/or installation method of the shaft seal assembly 10.
The fixed stator 20 may be formed with an annular recess 26 into which a
portion of the
floating stator 30 and/or sealing member 40 may be positioned. A predetermined
clearance
between the radial exterior surface 32 of the floating stator 30 (as well as
the axial exterior
surfaces thereof) and the interior surfaces of the annular recess 26 may be
selected to allow
for a predetermined amount of relative radial and/or axial movement between
the fixed stator
20 and floating stator 30. At least one pin 34 (which may be radially oriented
as in the
embodiment shown in FIGS. 16A & 16B) may be engaged with the floating stator
30 at a
second pin recess 35, and a portion of the pin 34 may extend into a recess 42
formed in the
sealing member 40. Additionally, other pins (not shown, but which may be
axially oriented)
also may be engaged with the floating stator about a first pin recess 33, and
a portion of that
pin may extend into a face plate pin recess 22a. In the illustrative
embodiment shown in
FIGS. 16A & 16B, the pins 35 may mitigate relative rotation between the
floating stator 30
and the sealing member 40. Axially oriented pins (not shown) may mitigate
relative rotation
between the floating stator 30 and the fixed stator 20. The axial interfaces
between the
floating stator 30 and fixed stator 20 may be sealed with seals 28, which
seals 28 may be
positioned in fixed stator seal grooves 20a and/or face plate seal grooves
22b. The seals 28
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may be configured as o-rings, but may be differently configured in other
embodiments of the
shaft seal assembly 10 without limitation.
The floating stator 30 may also be formed with a concave surface 38 in a
radial interior
portion thereof This concave surface 38 may form a semi-spherical interface
with a
corresponding convex surface 48 formed in the radial exterior portion of the
sealing member
40. Accordingly, the shaft seal assembly 10 shown in FIGS. 16A & 16B may
accommodate
shaft 12 misalignment, shaft 12 radial movement, and shaft 12 axial movement
with respect
to the shaft seal assembly 10 and/or equipment housing in an identical and/or
similar manner
to that previously described for the shaft seal assemblies 25 shown in FIGS. 1-
12.
The illustrative embodiment of the shaft seal assembly 10 also may include
various fluid
conduits for applying a sealing fluid to the shaft seal assembly 10. The fixed
stator 20 may be
formed with one or more inlets 24 for introduction of a sealing fluid to the
shaft seal
assembly 10. The inlet 24 may be in fluid communication with the annular
recess 26 formed
in the fixed stator 20, which annular recess 26 may be in fluid communication
with one or
more radial passages (not shown) formed in the floating stator 30 and
extending from the
radial exterior surface 32 thereof to the concave surface 38 thereof.
Alternatively, or in
addition to the one or more radial passages, the second pin recess 35 formed
in the floating
stator 30 may be configured to allow a specific amount of sealing fluid to
traverse the length
of the second pin recess 35 in a radially inward direction. The radially
interior terminus of the
second pin recess 35 may be formed with a second pin recess enlarged portion
35a.
Alternatively, the floating stator 30 may be formed with a floating stator
annular groove 37
on the concave surface 38 thereof These radial passages, second pin recess 35,
second pin
recess enlarged portion 35a, and/or floating stator annular groove 37 may
serve as a conduit
for sealing fluid from the annular recess 26 of the fixed stator 20 to the
convex surface 48 of
the sealing member 40. Accordingly, the scope of the shaft seal assembly 10 is
not limited by
the specific combinations of fluid conduits disclosed herein, but extends to
all configurations
of fluid conduits that may supply a sealing fluid to the sealing member 40.
The fixed stator 20 and/or seals 28 between the fixed stator 20 and floating
stator 30 may be
configured so that the majority of sealing fluid introduced to the inlet 24
passes through the
floating stator 30 (by any fluid conduit configuration, as explained above) in
a radially
inward direction. The semi-spherical interface between the floating stator 30
concave surface
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38 and the sealing member 40 convex surface 48 may be sealed with seals 28,
which seals 28
may be positioned in floating stator seal grooves 30a and/or sealing member
seal grooves (not
shown). The seals 28 may be configured as o-rings, but any suitable structure
and/or method
may be used without limitation. The floating stator 30, sealing member 40,
and/or seals 28
therebetween may be configured so that the majority of sealing fluid exiting
the floating
stator 30 passes through the sealing member 40 through a plurality of radial
bores 44 in a
direction from the convex surface 48 of the sealing member 40 to the radial
interior surface
46 thereof (i.e., in a generally radially inward direction, such that the
sealing fluid exits the
shaft seal assembly 10 adjacent the shaft 12).
The fixed stator 20, floating stator 30, and/or sealing member 40 may be
configured such that
the fluid conduits formed therein allow the majority of sealing fluid to exit
the shaft seal
assembly 10 from an area between the sealing member 40 and shaft 12 at a
predetermined
rate for a given set of operation parameters (e.g., sealing fluid viscosity,
pressure, and/or
volumetric flow rate, rpm of shaft 12, etc.). The illustrative embodiment of
the shaft seal
assembly 10 may be formed with thirty two (32) radial bores 44 in the sealing
member 40 in
corresponding pairs equally spaced about the circumference of the sealing
member, which is
best shown in FIGS. 17A & 17B. Each radial bore 44 may be formed with a radial
bore inlet
44a adjacent the convex surface 48 and a radial bore outlet 44b adjacent the
radial interior
surface 46. However, in other embodiments of the sealing member 40 not shown
herein, the
sealing member 40 may be configured with differently configured radial bores
44, different
numbers of radial bores 44, and/or different relative positions of radial
bores 44 without
limitation.
It is contemplated that the configuration of radial bores 44 shown in the
embodiment of a
sealing member 40 pictured in FIGS. 17A and 17B may be more efficient than
other
configurations in that a lower volumetric flow rate of sealing fluid may be
required for a
given set of operational parameters when compared to the prior art.
Additionally, the smooth,
generally cylindrical configuration of the radial interior surface 46 may
create a pressurized
fluid barrier between the shaft 12 and the sealing member 40 at the interface
thereof (e.g., a
"lift-off' seal). This may lead to a nearly frictionless shaft seal assembly
10 with no and/or
minimal contact between the shaft 12 and the sealing member 40 during
operation. However,
in other embodiments, different numbers, spacing, and/or configurations of the
fluid conduits
in the fixed stator 20, floating stator 30, and/or sealing member 40 may be
used without
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departing from the spirit and scope of the shaft seal assembly 10 as disclosed
and claimed
herein.
In light of the present disclosure, it will be apparent to those skilled in
the art that the
configuration of fluid conduits disclosed herein may be adapted to create a
pressurized fluid
barrier between any interface at which two elements are rotating with respect
to one another,
such as the articulated seal disclosed in U.S. Pat. No. 7,090,403. U.S. Pat.
No. 7,090,403 is
incorporated by reference herein in its entirety, and discloses embodiments of
a shaft seal
assembly having a spherical rotational interface between a rotor and a
floating stator (such as
those shown in FIGS. 13, 15, and 15A) and embodiments of a shaft seal assembly
having a
generally non-rotating spherical interface between two portions of a stator
(such as those
shown in FIGS. 14 and 14A). Accordingly, the scope of the shaft seal assembly
10 as
disclosed herein is not limited by the location and/or type of rotational
interface the shaft seal
assembly 10 is configured to accommodate.
For example, in an embodiment not pictured herein, the stator 30 of an
embodiment similar to
that shown in FIGS. 13, 15, and 15A may be configured with one or more
generally narrow
diameter radial bores (which may be generally similar to those shown in the
embodiment in
FIGS. 17A and 17B). Those radial bores may be configured so as to provide
fluid from an
external source (which may be in fluid communication with passage 40) to the
interface
between spherical surfaces on the stator portions 31, 31a (which may be
configured as a
concave surface on stator 31 and a convex surface on stator 31a).
Alternatively, the stator 31
may be configured with radial bores that serve to provide fluid from an
external source
(which may be in fluid communication with passage 40) to the interface between
stator 31a
and rotor 20, which may be a rotational interface having a labyrinth seal
pattern and/or one or
more seals (which may be configured as o-rings) therein.
The specific configuration and/or physical dimensions of the various features
of the fixed
stator 20, floating stator 30, and/or sealing member 40 (e.g., the radial
dimension of the
annular recess 26, the surface area of the concave surface 38 and/or convex
surface 48, the
diameter, length, and orientation of the radial bores 44, etc.) may vary
depending on the
specific application of the shaft seal assembly 10. These variations may be
utilized to
accommodate different sizes of shafts 12 and/or shaft seal assemblies 10 and
different
amounts and/or types of relative movement between a shaft 12 and shaft seal
assembly 10.
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The materials used to construct the shaft seal assemblies 10, 25 and various
elements thereof
will vary depending on the specific application, but it is contemplated that
bronze, brass,
stainless steel, or other non-sparking metals and/or metallic alloys and/or
combinations
thereof will be especially useful for some applications. Accordingly, the
above-referenced
elements may be constructed of any material known to those skilled in the art
or later
developed, which material is appropriate for the specific application of the
shaft seal
assembly 10, 25, without departing from the spirit and scope of the shaft seal
assemblies 10,
25 as disclosed and claimed herein.
Having described the preferred embodiments, other features of the shaft seal
assemblies 10,
25 will undoubtedly occur to those of ordinary skill in the art, as will
numerous modifications
and alterations in the embodiments as illustrated herein, all of which may be
achieved
without departing from the spirit and scope of the shaft seal assemblies 10,
25 disclosed
herein. Accordingly, the methods and embodiments pictured and described herein
are for
illustrative purposes only.
It should be noted that the shaft seal assemblies 10, 25 are not limited to
the specific
embodiments pictured and described herein, but are intended to apply to all
similar
apparatuses and methods for accommodating shaft(s) misalignment with respect
to a housing
and/or shaft seal assembly 10, 25, whether the misalignment is angular,
radial, and/or axial;
and for configuring a shaft seal assembly 10 to create a pressurized fluid
barrier between a
rotating element and a non-rotating element. Modifications and alterations
from the described
embodiments will occur to those skilled in the art without departure from the
spirit and scope
of the shaft seal assemblies 10, 25.
