U.S. patent number RE39,948 [Application Number 11/111,975] was granted by the patent office on 2007-12-25 for seal bearing assembly for use in a solid waste comminutor.
This patent grant is currently assigned to JWC Environmental. Invention is credited to Joseph W. Chambers, Sr., Craig J. Fennessy, Robert T. Sabol.
United States Patent |
RE39,948 |
Chambers, Sr. , et
al. |
December 25, 2007 |
Seal bearing assembly for use in a solid waste comminutor
Abstract
A solid waste material comminuting system having .[.a.].
.Iadd.an .Iaddend.electric motor for providing rotary motion, a
pair of cutter stacks with cutter elements of one stack interleaved
with cutter elements of the other, and gear means to transmit the
rotary motion of the electric motor to counter-rotate cutter
elements of one stack with cutter elements of the other. Each of
the cutter stacks comprises a central shaft journaled for rotation
and a .Iadd.seal-.Iaddend.bearing .Iadd.assembly/.Iaddend.module at
each end of the central shafts. Each .[.bearing.].
.Iadd.assembly/.Iaddend.module comprises an end housing, and a pair
of insertable pre-assembled .Iadd.seal-.Iaddend.bearing
.Iadd.elements/.Iaddend.assemblies mountable in each of said end
housings. One .Iadd.seal-.Iaddend.bearing
.Iadd.element/.Iaddend.assembly has a thru-hole for journaling a
first shaft for rotation and a second .Iadd.seal-.Iaddend.bearing
.Iadd.element/.Iaddend.assembly has a thru-hole for journaling a
second shaft for rotation.
Inventors: |
Chambers, Sr.; Joseph W.
(Rancho Mirage, CA), Sabol; Robert T. (Aliso Viejo, CA),
Fennessy; Craig J. (Huntington Beach, CA) |
Assignee: |
JWC Environmental (Santa Ana,
CA)
|
Family
ID: |
26758891 |
Appl.
No.: |
11/111,975 |
Filed: |
April 22, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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08077106 |
Jun 16, 1993 |
5354004 |
|
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Reissue of: |
08275724 |
Jul 19, 1994 |
05478020 |
Dec 26, 1995 |
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Current U.S.
Class: |
241/236; 384/144;
384/282; 384/480; 384/489 |
Current CPC
Class: |
B02C
18/0092 (20130101); B02C 18/142 (20130101); B02C
18/16 (20130101); B02C 2018/188 (20130101) |
Current International
Class: |
B02C
7/04 (20060101); F16C 33/80 (20060101) |
Field of
Search: |
;241/235,236,101.2,144,280,282,480,489 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Specifications for Residuals Treatment Facilities Phase 1, Deer
Island, Boston Massachusetts, Part B, Technical Specifications Vol.
III of VII, Massachusetts Water Resources Authority Contract No.
5723, Contract Package No. 301, pp. 1-11, Apr. 26, 1991. cited by
other .
Submittal Data--Generostee Creek W.W.T.P., Anderson, South
Carolina; Chambers Environmental Int'l S.O. #19126, Jul. 25, 1990.
cited by other .
Submittal Data--Nassau County Correctional Center, JWC
Environmental S.O. #19488, Dec. 10, 1990. cited by other .
Submittal Data--Dilly, Texas; JWC Environmental S.O. #20306, Dec.
19, 1990. cited by other .
Submittal Data--Castle Valley, Daylestown, Pennsylvania; JWC
Environmental S.O. #20378, Jan. 15, 1991. cited by other .
Submittal Data--Melbourne Airport, Melbourne, Florida; JWC
Environmental S.O. #20513, Jan. 30, 1991. cited by other .
Submittal Data--Westbrook, Maine; JWC Environmental S.O. #20748,
Feb. 25, 1991. cited by other .
Submittal Data--Carlinville, Illinois; JWC Environmental S.O.
#20783, Feb. 26, 1991. cited by other .
Submittal Data--Kalamazoo, Michigan; JWC Environmental S.O. #20769,
Feb. 26, 1991. cited by other .
Resubmittal Data--South Shore, Milwaukee, Wisconsin; Chambers
Environmental Int'l S.O. #19354, Mar. 7, 1991. cited by other .
Submittal Data--Theresa Street Plant, Lincoln, Nebraska; JWC
Environmental S.O. #19896, Mar. 8, 1991. cited by other .
Submittal Data--Mead Paper, Kingsport, Tennessee; JWC Environmental
S.O. #20972, Mar. 15, 1991. cited by other .
Submittal Data--Chalfont-New Britain Township Joint Sewage
Authority, Doylestown, Pennsylvania; JWC Environmental S.O. #20938,
Mar. 18, 1991. cited by other .
Submittal Data--New York City, Wards Island Sludge Dewatering
Facility; JWC Environmental S.O. #19491, Mar. 20, 1991. cited by
other.
|
Primary Examiner: Eley; Timothy V.
Attorney, Agent or Firm: Sughrue Mion PLLC
Parent Case Text
This is a continuation of application Ser. No. 08/077,106 filed
Jun. 16, 1993 now U.S. Pat. No. 5,354,004.
Claims
We claim:
1. A seal bearing assembly for use in a comminuting solid waste
material device having a pair of cutting stacks with cutter
elements of one stack interleaved with cutter elements of the
other, drive means to produce counter-rotation of cutter elements
of one stack with cutter elements of the other, each of said cutter
stacks comprising a central shaft journaled for rotation proximate
each .Iadd.end.Iaddend.; said seal-bearing assembly comprising; an
end housing, a pair of insertable preassembled
.Iadd.seal-.Iaddend.bearing elements mountable in said end housing,
one .Iadd.seal-.Iaddend.bearing element having a thru-hole for
journaling a first shaft for rotation and a second
.Iadd.seal-.Iaddend.bearing element having a thru-hole for
journaling a second shaft for rotation and a seal for each of said
first and second .Iadd.seal-.Iaddend.bearing elements to provide
fluid isolation between said end housing and said first and second
.Iadd.seal-.Iaddend.bearing elements.
2. The bearing assembly of claim 1, wherein said preassembled
.Iadd.seal-.Iaddend.bearing elements .[.comprises.]. .Iadd.comprise
.Iaddend.a seal cartridge, a spring mounted on the seal cartridge,
a dynamic race biased by said spring, a bearing cartridge, a static
race mounted on said bearing cartridge, a bearing .Iadd.of said
seal-bearing element being .Iaddend.mounted in said bearing
cartridge and means to secure said bearing in said bearing
.[.element.]. .Iadd.cartridge .Iaddend.and to urge said static race
into contact with said dynamic race.
3. The bearing assembly of claim 2 .[.further comprising.].
.Iadd.wherein a .Iaddend.seal .Iadd.of said seal-bearing element
comprises .Iaddend.means to .[.fluid.]. .Iadd.fluidly
.Iaddend.isolate said bearing from said static race.
4. The bearing assembly of claim 2 further comprising spring means
to bias said bearing cartridge in said end housing.
5. The bearing assembly of claim 2, .Iadd.wherein said preassembled
seal-bearing elements .Iaddend.further .[.comprising.].
.Iadd.comprise .Iaddend.a spring to bias said static race and
provide axial float for said static and dynamic races.
6. The bearing assembly of claim 1 further comprising a labyrinth
positioned on top of both .Iadd.seal-.Iaddend.bearing elements,
said labyrinth insertable onto said end housing and having a flange
conforming in shape to a portion of said end assembly proximate to
said cutter stacks.
7. The bearing assembly of claim 1 further comprising a labyrinth
mountable on said end housing and protruding in part into an
.[.enfluent.]. .Iadd.effluent .Iaddend.stream, said labyrinth
having a bearing surface that causes said labyrinth to elastically
deform and compensate for .[.variation sin.]. .Iadd.variations in
.Iaddend.cutter stack height.
8. A seal-bearing module for use in a solid waste material
comminuting system having a pair of cutter stacks with cutter
elements of one stack interleaved with cutter elements of the
other, an electric motor to counter-rotate cutter elements of one
stack with cutter elements of the other, said seal-bearing module
comprising; an end housing, and a pair of insertable pre-assembled
.Iadd.seal-.Iaddend.bearing assemblies mountable in said end
housing, one .Iadd.seal-.Iaddend.bearing assembly having a
thru-hole for journaling a first shaft for rotation and a second
.Iadd.seal-.Iaddend.bearing assembly having a thru-hole for
journaling a second shaft for rotation and a seal for each of said
.Iadd.seal-.Iaddend.bearing assemblies to isolate each of the
.Iadd.seal-.Iaddend.bearing assemblies from said end housing.
9. The seal-bearing module of claim 8, wherein said preassembled
.Iadd.seal-.Iaddend.bearing assemblies .[.comprises.].
.Iadd.comprise .Iaddend.a .[.seals.]. .Iadd.seal
.Iaddend.cartridge, a spring mounted on the seal cartridge, a
dynamic .[.rate.]. .Iadd.race .Iaddend.biased by said spring, a
bearing cartridge, a static race mounted on said bearing cartridge,
a bearing .Iadd.of said seal-bearing assembly being
.Iaddend.mounted .[.in.]. .Iadd.on .Iaddend.said bearing cartridge
and means to secure said bearing in said bearing .[.assembly.].
.Iadd.cartridge.Iaddend..
10. The seal-bearing module of claim 9 .[.further comprising.].
.Iadd.wherein a seal of said .Iaddend.seal.Iadd.-bearing assembly
comprises .Iaddend.means to .[.fluid.]. .Iadd.fluidly
.Iaddend.isolate said bearing from said static race.
11. The seal-bearing module of claim 9 further comprising spring
means to bias said bearing cartridge in said end housing.
12. The seal-bearing module of claim 9, .Iadd.wherein said
preassembled seal-bearing assemblies .Iaddend.further
.[.comprising.]. .Iadd.comprise .Iaddend.a spring to bias said
static race and provide axial float for said static and dynamic
races.
13. The seal-bearing module of claim 8 further comprising a
labyrinth positioned on top of said seal-bearing module to provide
a wear interface between said seal-bearing module and an
.[.enfluent.]. .Iadd.effluent .Iaddend.flow, said labyrinth
conforming to a portion of said end assembly to provide a removable
mounting surface.
.Iadd.14. The assembly of claim 1, wherein said pre-assembled
seal-bearing elements each include a bearing housing and a seal
housing..Iaddend.
.Iadd.15. The assembly of claim 14, wherein said bearing housing is
configured to receive a bearing structure of said pre-assembled
seal-bearing element..Iaddend.
.Iadd.16. The assembly of claim 15, wherein said bearing structure
is fixedly retained in said bearing housing..Iaddend.
.Iadd.17. The assembly of claim 1, wherein said pre-assembled
seal-bearing elements each include a seal housing..Iaddend.
.Iadd.18. The assembly of claim 17, further comprising a dynamic
race and a static race, wherein said dynamic race and said static
race are retained by a flange of said seal housing..Iaddend.
.Iadd.19. The assembly of claim 17, wherein each of said seal
housings defines a thru-hole for journaling said first and second
shafts respectively..Iaddend.
.Iadd.20. The module of claim 8, wherein said pre-assembled
seal-bearing assemblies each include a bearing housing and a seal
housing..Iaddend.
.Iadd.21. The module of claim 20, wherein said bearing housing is
configured to receive a bearing structure of said pre-assembled
seal-bearing assembly..Iaddend.
.Iadd.22. The module of claim 21, wherein said bearing structure is
fixedly retained in said bearing housing..Iaddend.
.Iadd.23. The module of claim 8, wherein said pre-assembled
seal-bearing assemblies each include a seal housing..Iaddend.
.Iadd.24. The module of claim 23, further comprising a dynamic race
and a static race, wherein said dynamic and static races are
retained by a flange of said seal housing..Iaddend.
.Iadd.25. The module of claim 23, wherein each of said seal
housings defines a thru-hole for journaling said first and second
shafts respectively..Iaddend.
.Iadd.26. A seal bearing assembly for use in a comminuting solid
waste material device having a pair of cutting stacks with cutter
elements of one stack interleaved with cutter elements of the
other, drive means to produce counter-rotation of cutter elements
of one stack with cutter elements of the other, each of said cutter
stacks comprising a central shaft journaled for rotation proximate
each end; said seal-bearing assembly comprising; an end housing, a
pair of insertable preassembled seal-bearing elements mountable in
said end housing, one seal-bearing element having a thru-hole for
journaling a first shaft for rotation and a second seal-bearing
element having a thru-hole for journaling a second shaft for
rotation and a seal for each of said first and second seal-bearing
elements to provide fluid isolation between said end housing and
said first and second seal-bearing elements, said insertable
preassembled bearing elements each comprising a bearing housing and
seal housing..Iaddend.
.Iadd.27. The assembly of claim 26, wherein said bearing housing is
configured to receive a bearing structure of said pre-assembled
seal-bearing element..Iaddend.
.Iadd.28. The assembly of claim 27, wherein said bearing structure
is fixedly retained in said bearing housing..Iaddend.
.Iadd.29. The assembly of claim 26, further comprising a dynamic
race and a static race, wherein said dynamic and static races are
retained by a flange of said seal housing..Iaddend.
.Iadd.30. The assembly of claim 26, wherein each of said seal
housings defines a thru-hole for journaling said first and second
shafts respectively..Iaddend.
.Iadd.31. A seal-bearing module for use in a solid waste material
comminuting system having a pair of cutter stacks with cutter
elements of one stack interleaved with cutter elements of the
other, an electric motor to counter-rotate cutter elements of one
stack with cutter elements of the other, said seal-bearing module
comprising; an end housing, and a pair of insertable pre-assembled
seal-bearing assemblies mountable in said end housing, one
seal-bearing assembly having a thru-hole for journaling a first
shaft for rotation and a second seal-bearing assembly having a
thru-hole for journaling a second shaft for rotation and a seal for
each of said seal-bearing assemblies to isolate each of the bearing
assemblies from said end housing, said insertable preassembled
bearing assemblies each comprising a seal-bearing housing and seal
housing..Iaddend.
.Iadd.32. The module of claim 31, wherein said bearing housing is
configured to receive a bearing structure of said pre-assembled
seal-bearing assemblies..Iaddend.
.Iadd.33. The module of claim 32, wherein said bearing structure is
fixedly retained in said bearing housing..Iaddend.
.Iadd.34. The module of claim 31, further comprising a dynamic race
and a static race, wherein said dynamic and static races are
retained by a flange of said seal housing..Iaddend.
.Iadd.35. The module of claim 31, wherein each of said seal
housings defines a thru-hole for journaling said first and second
shafts respectively..Iaddend.
Description
BACKGROUND OF INVENTION
This invention relates to a solid waste comminuting apparatus. Such
devices have been established in the art and are now widely used in
a variety of industrial applications, such as municipal waste
treatment and industrial applications. Reference is made to U.S.
Pat. No. 4,046,324, which discloses such a basic system that has
achieved commercial success.
By definition, comminution is the reduction of particle size of
solid waste material to minute particles. It is generally performed
by shearing, shredding and crushing of the waste material. As set
forth in the '324 patent, comminution occurs by utilizing a pair of
counter-rotating intermeshed cutting members.
The solid waste material is fed into the interface between cutting
elements, typically utilizing a fluid carrier medium, and shearing
action occurs because the two cutters overlap each other such that
opposing forces of counter-rotation of the cutting elements on the
different stacks act on the solid material as it passes through the
device.
In practice, such devices are generally used in an enfluent path.
That is, the solid material is generally entrained in a liquid and
the device is placed directly in the liquid stream. By having the
solid material entrained in a liquid stream transportation of the
material to and from the unit occurs. Further, by softening the
solid particles, a greater degree of comminution is achieved.
Devices of the type disclosed in the '324 patent have found
commercial success and are widely used in waste treatment
facilities, shipboard use and the like. As can be appreciated, the
environment of use is very harsh for the equipment and as such,
routine maintenance is required in both a preventative sense and
also to immediately repair break downs when they occur thus
minimizing system down-time.
An important aspect of such maintenance and repair is the integrity
of the seals which provide the cutter stacks to rotate while
minimizing friction. Given the mass of the cutter stacks together
with high motor torque, loads on the seals are large and thus seal
integrity is a primary consideration. In the past, two-shafted
machines such as the '324 device required that the seal assembly be
an integral part of the device. Such is illustrated in FIG. 1 of
the '324 patent. As a result, if there was a seal failure other
critical components of the device were likely to be effected. This
failure of a seal could thus mean that bearings could fail and
seize up the cutter stack.
Importantly, to repair the seal assembly, in the prior art, there
was a requirement that the device be disassembled and completely
reassembled. In the context of a unit which is used in fluid waste
treatment that down-time, in some cases as long as a day could have
detrimental effects in the ability of a plant to process waste.
Such would require rerouting solid waste, shutting down a portion
of the facility and otherwise result in an inefficient
operation.
Moreover, in prior art two-shafted machines, the cutter stack and
the various seal components were integral and in-line with a fixed
geometry. Consequently, tightening of the cutter stack, by
compression, resulted in compression of the seals. Again, such is
illustrated in FIG. 1 of the '324 patnet. It has been recognized
however, that under normal operating conditions the cutter
thickness experiences wear and thus the overall thickness of the
stack tends to reduce over time. The result is an effective
reduction in the overall stack height and the stack therefore tends
to become loose. As a consequence, initial compression of various
seal components is lost and the seal faces tend to separate. The
result is leakage across the seal with the subsequent result of
bearing failure.
Another deficiency in the prior art was the use of a labyrinth
between the main fluid chamber and the seal faces. The labyrinth
was generally incorporated into the seal components as sacrificial
component. Because such devices are used in applications which
include a high grit content, the labyrinth tended to be a
relatively high wear component. As a consequence, seal components
had to be removed to replace the labyrinth with the potential for
seal damage upon reassembly.
SUMMARY OF THE INVENTION
Given these deficiencies in the prior art, it is an object of this
invention to provide an improved solid waste comminutor that
overcomes the operational and assembly problems of prior
devices.
It is a further object of this invention to provide a solid waste
comminutor which employs a cartridge with a balanced seal-bearing
design to produce a constant seal face pressure.
A further object of this invention is to provide a solid waste
comminutor of improved seal and bearing life by improved seal
effectiveness which is independent of stack tightness.
Yet another object of this invention is to provide a seal cartridge
for a solid waste comminutor which has an independent labyrinth
that can be replaced without disassembly of the seal-bearing
structure.
Another object of this invention is to provide an improved solid
waste comminutor that utilizes a separate wear piece independent of
the seal cartridge which itself may be pre-loaded to provide a
spring force for the cutter stack.
These and other objects of this invention are achieved by a dual
stack solid waste comminutor having preassembled bearing-sealed
elements that are replaceable individually. That modular assembly
improves system life while minimizing down-time. In accordance with
this invention a cartridge type seal is employed utilizing two
modular assemblies, one on each end of the cutter stack. Each of
the modular bearing-seal assemblies comprises a pair of identical
bearing-seal cartridges. Two identical bearing-seal cartridges are
assembled into the end housing to thus form top and bottom modular
pairs.
Further, in accordance with this invention the bearing-seal
cartridges float within the housing to provide movement with shaft
movement thereby reducing the stress on the shafts and
bearings.
A quick exchange of the mechanical subassembly, which includes
bearings, O-ring seals and cartridge housing itself can be
effectuated. As a result of this modular assembly, an individual
seal cartridge can be installed quickly without the need to
disassemble the entire subassembly.
Another advantage of this technique is that the bearing-seal
cartridge is identical for the top and bottom of the cutter stack.
As a consequence, a deficiency in the prior art which used two
different assemblies has been eliminated. The bearing-seal
cartridge is an item which is pre-assembled and installed as
received. Thus, there is no requirement that the individual items,
the various races bearings and the like be assembled at the job
site. Rather, the cartridge is interchangeable as a unit and is
inserted into the end housing.
Further, in accordance with this invention by re-torquing of the
cutter stack can be accomplished while the unit is still in-line
and installed. It has been demonstrated that in practice, the most
common preventative maintenance function is re-torquing the cutter
stack to maintain stack compression for maximum cutting
efficiency.
Prior to this invention a loss of stack compressibility lead
directly to premature seal and bearing failure, primarily of the
bottom seal assembly. In accordance with this invention, the
tightness of the seal assembly is independent of total stack
height, since it is designed as a self contained unit no
disassembly is required.
Another advantage of this invention is an early warning seal
failure detection system which can be used to prevent premature
bearing failure. The invention provides for a drain port and/or
weep holes in the shafts that allow fluid permeating from the seal
to escape to the exterior. This can thus be viewed by maintenance
personnel during routine checks of the system.
These and other objects of this invention will become apparent by a
review of the attached drawing and the description of the preferred
embodiment which follows.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a cut-away side view of the overall comminution system of
this invention; and
FIG. 2 is a schematic view illustrating the .[.seal.]. cartridges
and their assembly .[.to form a dual seal cartridge.]. .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a cut-away side view of the overall system
is depicted. In FIG. 1 the housing 1 has an inlet and outlet, not
illustrated. At the bottom of the housing, a pair of access
cut-outs 4 are provided to permit stack tightening, to be described
herein, without disassembly of the device. The unit employs, three
essential subsystems, which comprise a complete comminution
apparatus 10. These are a drive subsystem 11 with a motor 24 and
speed reducer 12, a gearing subsystem 14, and a cutting subsystem
16. The housing 26 for the speed reducer 12 is mounted to the gear
and cutter system 14, 16 by a pair of conforming flange elements
18, 20, which are clamped together by means of bolts 22. The motor
is typically an electric drive motor 24, the details of which need
not be discussed in detail. It will be recognized by those skilled
that a suitable motor and drive system can be employed consistent
with the scope of intended use. The speed reducer is contained in a
housing 26 and employs an input shaft 30 and an output shaft 28.
The input shaft 30 is journaled for rotation using a coupling 32 to
the motor 24. This provides axial and radial alignment of the motor
unit 24 with the speed reducer 12.
The output shaft 28 of the speed reducer 12 passes through a
transition piece 34 in which the output shaft 28 is keyed to a
drive shaft 36 of one cutter stack by means of a coupling 35. The
drive shaft 36 carries a gear 38. The drive shaft 37 of the other
cutter stack carries a gear 40. Both gears 38 and 40 are housed in
housing 42 of the gear unit 14. The two gears provide
counter-rotation to a pair of cutter stacks 44, 46. That is, shaft
36 is the drive shaft and shaft 37 is the driven shaft which
counter-rotates due to gears 38, 40.
Each of the cutter stacks 44, 46 comprises an alternating sequence
of cutting elements 48 and spacers 50. As illustrated in FIG. 1,
the interface is such that by beginning the stack 44 with a cutter
element and stack 46 with a spacer element the cutter elements
interleave with each other in the area between the two cutter
stacks, which has been denoted by numeral 52. It is this
interactive pair of stacks in zone 52 which provides the shredding
of material as it passes through the cutter elements.
The cutter elements themselves may be either the same on each stack
or differ from stack to stack. For example, it has been found that
having eleven teeth on one cutter element and five on the opposing
element improves the clean-out efficiency of the unit. Moreover,
the geometry of the cutter elements may also be different in
addition to the variations in the number of teeth.
As illustrated in FIG. 1, the cutter stack 16 is supported top and
bottom by means of a pair of bearing-seal assemblies.Iadd./modules
.Iaddend.54, 56. FIG. 2 illustrated in greater detail those two
subassemblies.
Referring now to FIG. 2, the assemblies.Iadd./modules .Iaddend.54
and 56 are explained in greater detail. It will be understood from
reference to FIG. 1 that the assembly on top 54 is the same as the
assembly on the bottom 56, the unit simply being inverted. FIG. 2
illustrates the seal bearing assembly 56. The units are assembled
into respective end housings, 58 and 60. FIG. 2 illustrates the end
housing 60. As illustrated.Iadd., .Iaddend.two identical
bearing-seal cartridges are employed in the end housing. FIG. 2
illustrates .[.on seal.]. .Iadd.one element/.Iaddend.assembly 62 in
place with a second .[.seal.]. .Iadd.element/.Iaddend.assembly 64
.Iadd.being .Iaddend.inserted into the end housing 60.
Illustrated in phantom line in FIG. 2 are the ends 66, 68 of the
shafts 36 and 37 for the respective cutter assemblies 44 and 46. It
will be understood that the shaft ends 66 and 68 protrude through
the respective seal cartridges but are held in place by end nuts
69. Stack tightness is achieved by tightening the end nuts 69.
Access is via the cut-outs 4 so that an individual stack may be
tightened. O-rings 70, and 72 are employed to provide a fluid tight
seal for each shaft.
As illustrated in FIG. 2, the bearing-seal cartridge comprises a
cartridge housing 74 with an outer flange 76 and an inner tubular
portion 78. A spring 80 is inserted between the flange portion 76
and the cylindrical portion 78. A dynamic race 82 sealed by means
of an O-ring 84 is placed relative to the spring 80 and the
cylindrical portion 78. This spring provides a means by which the
race 82 is provided with float.
A static race 86 with an O-ring 84 forms the dual race structure.
The race is held in place by means of the bearing cartridge 88
having a flange element 91 to cage the static race into position
and to also limit axial travel of the dynamic race. The dynamic
race 82 has a face in contact with a confronting face of static
race 86. A bearing structure 90 is housed inside the bearing
cartridge and is held in place by means of a retaining ring, such
as a snap ring illustrated as element 92.
A second spring 87 may optionally be used to allow the races 82 and
86 to axially float. The advantage is prevention of potential skew
of the faces of the races relative to each other.
As illustrated in FIG. 2, the second .[.seal cartridge.].
.Iadd.element/assembly .Iaddend.has an identical construction of
its elements. The units are held in place and are biased by means
of springs 94, 96. Those springs provide float for the bearing-seal
cartridges .Iadd.62, .Iaddend.64.[., 66.]. .
Sealing occurs by means of O-rings 98, 100. It will be appreciated
that with respect to the .[.seal.]. cartridge illustrated in its
installed position on the right hand side of FIG. 2 the same
elements are present. They have been denoted with prime numbers to
connote the same numbering sequence.
While not illustrated, it is apparent from FIG. 1 that the upper
end housing, inverted having a pair of identical .[.seal.].
cartridges is employed. The upper end seal-bearing module may be
provided with an upper spacer 103. This spacer rests on the outer
race to preload the top bearing stack as the housing 42 is mounted
on the housing 58 via bolts 104.
Importantly, in accordance with this invention the labyrinth
illustrated by dotted lines with numeral 102 is not a part of the
seal.Iadd.-bearing .Iaddend.assembly. Rather, the labyrinth is
considered to be a part of the stack assembly and is separated from
the .[.seal.]. cartridge .[.assembly.]. itself. The labyrinth 102
protrudes to the .[.enfluent.]. .Iadd.effluent .Iaddend.stream
where it is subjected to particles and the like while the device is
in operation. Hence, it is a component that wears and must, from
time to time be replaced. In accordance with this invention, the
labyrinth 102 can be replaced as a single component since it is
merely placed into the annular groove 108 of the housing 60. It is
compressed into position by a force applied through annular raised
surface 110 that loads the labyrinth on surface 111, .Iadd.and
.Iaddend.causes it to slightly deflect. This deflection serves to
compensate for wear in the cutter stack.
As is apparent from FIGS. 1 and 2, this construction offers a
number of important advantages. First, given the fact that the
.Iadd.seal-.Iaddend.bearing.[.-seal.]. assemblies .[.are a.].
.Iadd.include .Iaddend.modular .[.cartridge assembly.].
.Iadd.cartridges.Iaddend., repair .[.of a seal assembly.]. requires
only that a pre-assembled cartridge 64 be installed in place of the
defective unit. Thus, the seal .Iadd.and bearing
.Iaddend.components .[.and the bearing elements.]. are combined
into a single cartridge .[.assembly.]. 64. This allows for
important advantages over the prior art in that the individual
components do not have to be disassembled at a job site.
Secondly, by this invention stack tightening occurs independent of
compression forces on the seal components. This occurs because, in
accordance with this invention, the cartridges themselves are
positioned and loaded independent of the cutter stack. That is the
housing 58 is attached to gear housing 42 by means of the bolts
104. Tightening the cutter stacks by means of the nuts 69 does not
increase the forces on the bearings or seals. Rather, the force is
a function of the spring force of the spring 80.
In the case of the upper assembly, axial positioning is obtained by
the spacer 103 which opposed by spring 94 as the unit is bolted by
means of bolts 104. The bottom assembly is allowed to float. The
bottom assembly is mounted by means the mounting bolts 106. The use
of a spacer is eliminated. It is understood that the cover plates
and mounting structure of the housing 1 have been eliminated.
This invention also includes a provision of leak detection by means
of a leak detection plug 108. Thus, an upper seal failure can be
ascertained by fluid in the upper housing via the leak detection
plug 108. If there is any water in the warea, it will alert
personnel that there is a potential failure in the upper
bearing-seal.
Additionally, a leakage path can be provided in each of the shafts
36, 37. To the extent that fluid permeates the seal it will thus
escape to the exterior where it can be viewed during routine
maintenance checks.
As set forth in this invention, in accordance with this invention a
cartridge type bearing-seal 64 allows for replacement of units on
an individual basis as opposed to replacement of the entire seal
pair at the top or bottom of the cutter stack. Additionally, the
entire assembly with the bearings intact can be removed from the
housing for servicing. Given the construction of those cartridge
elements tightening of the cutter stack can be accomplished without
impairing the effectiveness of the seal. That is, compression of
the seal components themselves occurs during the assembly of each
of the seals cartridge units illustrated in FIG. 2. Thus, the
integrity of those units is accomplished independent of the
tightness of the cutter stack.
Moreover, as illustrated in FIGS. 1 and 2 the labyrinth 102 is
placed between the main fluid chamber and either of the seal faces.
In this invention the labyrinth 102 is distinct and separate from
each of the seal cartridges. To the extent that the labyrinth
requires replacement, it can be done by removing the cartridge,
inserting a new labyrinth and then reinstallation of the cartridge
56, 60 without any disassembly of the seal components.
It will be apparent to those of skill in this technology that
modifications of this invention can be made without departing from
the essential scope thereof.
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