U.S. patent application number 13/369987 was filed with the patent office on 2013-08-15 for seal arrangement along the shaft of a liquid ring pump.
The applicant listed for this patent is Richard Cadotte, Athanasios DIAKOMIS, Michael A. Mulholland. Invention is credited to Richard Cadotte, Athanasios DIAKOMIS, Michael A. Mulholland.
Application Number | 20130209251 13/369987 |
Document ID | / |
Family ID | 48945692 |
Filed Date | 2013-08-15 |
United States Patent
Application |
20130209251 |
Kind Code |
A1 |
DIAKOMIS; Athanasios ; et
al. |
August 15, 2013 |
SEAL ARRANGEMENT ALONG THE SHAFT OF A LIQUID RING PUMP
Abstract
A first bore is formed in a liquid ring pump. A shaft is in the
first bore. A second bore is formed in the pump and is axially
inward of the first bore. A first and second seal are in the second
bore and around the shaft. The second seal is axially outward of
the first seal. The second seal is free of an abutment axially
outward of it and abutting up against it.
Inventors: |
DIAKOMIS; Athanasios;
(Seymour, CT) ; Mulholland; Michael A.; (Troy,
MO) ; Cadotte; Richard; (Norwalk, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DIAKOMIS; Athanasios
Mulholland; Michael A.
Cadotte; Richard |
Seymour
Troy
Norwalk |
CT
MO
CT |
US
US
US |
|
|
Family ID: |
48945692 |
Appl. No.: |
13/369987 |
Filed: |
February 9, 2012 |
Current U.S.
Class: |
415/230 |
Current CPC
Class: |
F04C 27/009 20130101;
F04C 2230/85 20130101; F04C 19/00 20130101 |
Class at
Publication: |
415/230 |
International
Class: |
F04D 29/10 20060101
F04D029/10 |
Claims
1. A liquid ring pump comprising: a housing having an axis; a shaft
having a longitudinal axis parallel to said housing's axis and
offset therefrom, said shaft extending into said housing; a working
chamber formed in said housing; an inlet formed in said housing and
fluidly connected to said working chamber; an outlet formed in said
housing and fluidly connected to said working chamber; a rotor
fixedly coupled to said shaft and rotatable within said working
chamber; a first bore formed in said liquid ring pump, said shaft
in said first bore; a second bore formed in said pump and axially
inward of said first bore, a first and second seal in said second
bore and around said shaft, said second seal is axially outward of
said first seal, and wherein said second seal is free of an
abutment axially outward of it and abutting up against it.
2. The liquid ring pump of claim 1 wherein the second seal
comprises: a first sleeve and a second sleeve, said first and
second sleeves are coupled to one another and rotate relative to
one another; the shaft extends through an opening formed by the
first sleeve and contacts the first sleeve; the first sleeve is
fixed relative to the shaft and during operation of the pump
rotates with the shaft; the second sleeve contacts a surface of the
pump which forms the second bore, and during operation of the pump,
the second sleeve does not rotate relative to the surface of the
pump it contacts.
3. The liquid ring pump of claim 2 wherein the second sleeve
comprises: an axially extending flange having elastomeric material
thereon contacting said surface which forms said bore.
4. The liquid ring pump of claim 2 wherein the first sleeve
comprises: an axially extending flange having elastomeric material
thereon contacting said shaft.
5. The liquid ring pump of claim 4 wherein said first sleeve
further comprises: a radially extending flange.
6. The liquid ring pump of claim 5 wherein said radially extending
flange bounds an axial outward end of said bore.
7. The liquid ring pump of claim 5 wherein said radially extending
flange is an axially outwardly most facing side of said second
seal.
8. The liquid ring pump of claim 2 wherein said first seal has a
plurality of grooves therein.
9. The liquid ring pump of claim 8 wherein, a first groove of said
plurality of grooves is a circumferential groove extending along an
outer surface of said first seal; said first groove is at a first
axial end of said first seal.
10. The liquid ring pump of claim 9 wherein, a second groove of
said plurality of grooves is an inner circumferential groove
extending along an inner surfaced of said first seal; said second
groove radially opposite said first groove, said second groove at
said first axial end.
11. The liquid ring pump of claim 2 wherein, said second bore is
formed in a head of said liquid ring pump, said head has an inlet
and an outlet therein.
12. The liquid ring pump of claim 1 further comprising a third and
fourth bore, said shaft in said third and fourth bore, said fourth
bore axially inward of said third bore; said fourth bore having a
third and fourth seal in said fourth bore and around said shaft,
said fourth seal is axially outward of said third seal, and wherein
said fourth seal is free of an abutment axially outward of it and
abutting up against it.
13. A liquid ring pump comprising: a housing having an axis; a
shaft having a longitudinal axis parallel to said housing's axis
and offset therefrom, said shaft extending into said housing; a
working chamber formed in said housing; an inlet formed in said
pump and fluidly connected to said working chamber; an outlet
formed in said pump and fluidly connected to said working chamber;
a rotor fixedly coupled to said shaft and rotatable within said
working chamber; a first bore formed in said liquid ring pump, said
shaft in said first bore; a second bore axially inward of said
first bore, a first and second seal in said second bore and around
said shaft, said second seal is axially outward of said first seal,
and wherein said second seal comprises, a first sleeve and a second
sleeve, said first and second sleeves are coupled to one another
and rotate relative to one another; the shaft extends through an
opening formed by the first sleeve and contacts the first sleeve;
the first sleeve is fixed relative to the shaft and during
operation of the pump rotates with the shaft; the second sleeve
contacts a surface of the pump which forms the second bore, and
during operation of the pump, the second sleeve does not rotate
relative to the surface of the pump it contacts.
14. A method of retrofitting a liquid ring pump, a portion of said
liquid ring pump having a bore formed therein, at least one seal is
in said bore, said seal held in place by an abutment removeably
coupled to the portion of said pump forming said bore, said method
comprising: removing said abutment holding said seal in place;
removing said seal from said bore; placing at least one seal in
said bore axially outward of another seal in said bore; leaving
said seal placed in said bore free of an abutment axially outward
of it and abutting up against it.
15. The method of claim 13 wherein the step of placing at least one
seal in said bore further comprises: contacting a first sleeve of
said seal placed in said bore to a shaft of said pump so that said
first sleeve rotates with said shaft during operation of said pump;
contacting a second sleeve of said seal placed in said bore to
contact a surface forming said bore so that said second sleeve does
not rotate relative to said surface during operation of said
pump.
16. The method of claim 14 wherein said at least one seal is a
second seal and said method further comprises: placing a first seal
in said bore prior to placing said second seal in said bore
17. The method of claim 14 further comprising: forming a channel in
said liquid ring pump which opens up into said bore.
18. The method of claim 16 further wherein the channel is formed in
a head of the liquid ring pump and the channel opens through an
exterior surface of the head.
19. The method of claim 13 wherein the step of placing the at least
one seal in said bore includes arranging said seal as an axially
outward most seal in said bore.
20. A method of retrofitting a liquid ring pump, a portion of said
liquid ring pump having a bore formed therein, at least one seal is
in said bore, said seal held in place by an abutment removeably
coupled to said portion of said pump forming said bore, said method
comprising: removing said abutment holding said seal in place;
removing said seal from said bore; placing a seal in said bore;
contacting a first sleeve of said seal placed in said bore to a
shaft of said pump so that said first sleeve rotates with said
shaft during operation of said pump; contacting a second sleeve of
said seal placed in said bore to contact a surface forming said
bore so that said second sleeve does not rotate relative to said
surface during operation of said pump.
Description
FIELD OF INVENTION
[0001] The present disclosure concerns a seal arrangement in a bore
(stuffing box) and around a shaft of a liquid ring pump. The
arrangement is radially inward of a primary bearing assembly. The
arrangement can provide a secondary bearing support.
BACKGROUND
[0002] Liquid ring pumps are well known. In a known liquid ring
pump water or other liquid is introduced into the pump and
centrifugally flung outwardly by a rotating rotor to form an
annular ring of liquid with the stationary pump housing. The liquid
ring rotates within the housing and is centered about the
longitudinal axis of the housing. The rotational axis of the rotor,
however, is offset from the axis of the housing. Consequently as
the liquid ring rotates with the rotor, an air core, pocket or
chamber is formed within the liquid ring. The inner diameter of the
liquid ring is centered relative to the housing's axis but offset
from and eccentric relative to the pump's shaft axis. The liquid
volume in the housing is maintained to provide a seal at the outer
portions of the rotor blades isolating individual chambers or
buckets between adjacent rotor blades. At one point during a
complete rotation of the rotor, the bucket or chamber is almost
empty of liquid. As the rotor advances, liquid will fill the
chamber. As the rotor further advances liquid will recede from the
chamber until the chamber is almost empty again. As the liquid
recedes from the chamber, it is replaced by air or other gas
entering through the inlet of the pump. Then as the liquid is
forced back into the chamber or bucket, the air is compressed and
exits through the outlet of the pump.
[0003] U.S. Pat. No. 4,850,808, Schultze, discloses a liquid ring
pump. The pump is conically ported (conical liquid ring pump) and
has two stages. The pump includes a housing; a rotor assembly
within the housing; a shaft extending into the housing on which the
rotor assembly is fixedly mounted; and a motor assembly coupled to
the shaft. During operation, the housing is partially filled with
operating liquid so that when the rotor is rotating, the rotor
blades engage the operating or pumping liquid and cause it to form
an eccentric ring that converges and diverges in the radial
direction relative to the shaft. Where the liquid is diverging from
the shaft, the resulting reduced pressure in the spaces between
adjacent rotor blades of the rotor assembly (buckets) constitutes a
gas intake zone. Where the liquid is converging towards the shaft,
the resulting increased pressure in the spaces between adjacent
rotor blades (buckets) constitutes a gas compression zone. A cone
shaped sleeve is mated within a cone shaped bore of the rotor
assembly. The cone shaped sleeve is ported to allow gas that would
otherwise be carried over from the compression zone, to bypass the
intake zone and re-enter the compression zone.
[0004] U.S. Pat. No. 4,747,752, Somarakis, discloses a secondary
bearing in a bore of a liquid ring pump. The bore is formed by the
head and cone of the liquid ring pump. A lip seal is in the bore.
The lip seal is axially outward of the secondary bearing. A plate
or flange extending in the radial direction, at an axial outward
end of the bore is coupled to an axial outward surface of the head
forming the bore. The plate or flange abuts the lip seal and
prevents the seal and secondary bearing from moving outward in the
axial direction. A flange extending in the radial direction, at an
axial inward end of the bore, abuts the secondary bearing. The
flange prevents the lip seal and secondary bearing from moving
radially inward. The lip seal and secondary bearing are fixed
relative to the head and cone. Operating liquid enters and exits
the bore
[0005] Prior art FIG. 1 discloses a single stage liquid ring pump
10. The pump has a housing 12 with a shaft 14 extending into the
housing 12. A rotor 16 is fixedly mounted to the shaft 14. The pump
has an inlet 18 which leads into a gas intake zone 20. The pump has
an outlet 22 which leads out of the gas compression zone 24. During
operation of the pump 10 the rotor 16 rotates in the housing 12.
Air or gas 26 is drawn into the intake zone 20 through the inlet 18
and into the buckets formed between adjacent rotors blades 28. As
the rotor 16 rotates the operating liquid (not shown) fills the
buckets and the air or gas 26 is compressed and exits the pump 10
through the outlet 22.
[0006] The housing includes a central portion 30 that has an
interior surface 32 that forms a cylindrical chamber 34 around the
rotor 16. The cylindrical chamber can also be called a working
chamber. The intake zone 20 and compression zone 24 form the
working chamber. A first head 36 is coupled to a first axial end 38
of the central portion 30 and is at the first axial end of the
working chamber. The first head 36, which can also be called a
first cover, is at the outboard end of the liquid ring pump 10. The
housing has another cover 40 coupled to a second axial end 42 of
the central portion 30. The cover, which can also be called a
second cover or a power end cover, is at the second axial end of
the working chamber. The cover is at the power end of the liquid
ring pump. If the pump were a two stage pump the cover would be a
second head. The axis of the shaft 14 is offset, eccentric,
relative to the axis of the central portion 30.
[0007] A first primary bearing support 44 is coupled to an axially
outward facing side 46 of the first head 36. A first primary bore
48 is formed in the first bearing support 44. The shaft 14 extends
into the first primary bore 48. A first primary bearing assembly
50, which can also be called an outboard bearing assembly, is
disposed in the first primary bore 48 and around the shaft 14.
Axially inward of the first primary bearing assembly is a first
secondary bore 52.
[0008] The first secondary bore 52 can be called a first stuffing
box. The first secondary bore is formed in the first head 36. The
shaft 14 extends through the first secondary bore 52. A first
packing 54 is in the first secondary bore 52 and around the shaft
14. The packing 54 includes seals 56 extending circumferentially
around the shaft 14. The seals are rope seals. Axially between the
rope seals 56 is a lantern seal 58 which also forms part of the
packing. A packing gland 60, axially outward of the packing 54,
pushes and squeezes the packing axially inward to abut up against
flanges 62 that extend in the radial and axial direction at an
axial inward end of the first secondary bore 52. The gland 60 abuts
the packing 54. The gland is coupled to the head to overlap the
axially outward facing side 46 of the primary head by fasteners 67.
The gland 60 fixes the packing 54 against moving in the axial
direction and holds the packing in place. The packing 54 and gland
60 are fixed relative to the head 36. The packing is within the
bore 52. The gland is partially in the bore 52. The shaft 14
rotates within the packing 54 and relative to the packing. The
lantern seal 58 is fluidly connected to a supply of liquid. During
operation of the pump, the lantern seal allows for liquid to enter
and be distributed between the packing and shaft to provide
lubrication and a sealing function to prevent escape of air or gas
from the working chamber into bore 52.
[0009] A cone 84 coupled to the first head 36 extends axially
inward from an axially inward facing side 86 of the first head. The
cone 84 is coupled to the first head 36. The cone extends into a
complimentary bore formed by the rotor 16.
[0010] A second primary bearing support 64 is coupled to an axially
outward facing side 66 of the power end cover 40. A second primary
bore 68 is formed in the second primary bearing support 64. The
shaft 14 extends into the second primary bore 68. A second primary
bearing assembly 70, which can also be called a power end bearing
assembly, is disposed in the second primary bore 68 and around the
shaft 14. Axially inward of the second primary bearing assembly is
a second secondary bore 72. The second secondary bore can be called
a second stuffing box. The second secondary bore 72 is formed in
the power end cover 40. The shaft 14 extends through the second
secondary bore 72. A second packing 74 is in the second secondary
bore 72 and around the shaft 14. The packing 74 includes seals 76
extending circumferentially around the shaft 14. The seals are rope
seals. Axially between the rope seals 76 is a lantern seal 78 which
also forms part of the packing 74. A packing gland 80, axially
outward of the packing 74, pushes and squeezes the packing axially
inward to abut up against flanges 82 that extend in the radial
direction at an axial inward end of the second secondary bore 72.
The gland 80 abuts the packing. The gland 80 is coupled to the
housing to overlap an axially outward facing side 66 of the power
end cover 40 by fasteners 67. The gland 80 fixes the packing 74 so
that it does not move in the axial outward direction and holds the
packing in place. The packing 74 and gland 80 are fixed relative to
the cover 40. The packing is within the bore 72. The gland is
partially in the bore 72. The shaft 14 rotates within the packing
74 and relative to the packing. The lantern seal 78 is fluidly
connected to a supply of liquid. The lantern seal 78 allows for
liquid to enter and be distributed between the packing 74 and shaft
14 to provide lubrication and a sealing function to prevent escape
of air or gas from the working chamber into the bore 72.
[0011] The glands 60 and 80 are partially within their respective
bores and partially extending axially out ward from their
respective bores.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a cross section of a prior art single stage liquid
ring pump; the cross section is taken along a plane parallel to the
shaft; the cross section does not pass through the shaft.
[0013] FIG. 2 is a cross section of a single stage liquid ring pump
embodying the invention;
[0014] the cross section is taken along a plane parallel to the
shaft; the cross section does not pass through the shaft.
[0015] FIG. 3 is a close up of detail A shown in FIG. 2.
[0016] FIG. 4 is a close up representation of the cassette seal
shown in FIG. 3 surrounding a representation of the shaft shown in
FIG. 3.
[0017] FIG. 5 is a perspective view of the composite seal shown in
FIGS. 2 and 3.
[0018] FIG. 6 is a perspective view of a seal similar to the seal
shown in FIG. 5 except it has a split configuration.
SUMMARY
[0019] An example of the invention is embodied in a liquid ring
pump that has a housing with a longitudinally extending axis. The
pump has a shaft with a longitudinal axis parallel to said
housing's axis and offset therefrom. The shaft extends into the
housing. A working chamber is formed in the housing. An inlet is
formed in said housing and fluidly connected to the working
chamber. An outlet is formed in the housing and fluidly connected
to the working chamber. A rotor is fixedly coupled to the shaft and
rotatable within the working chamber. A first bore is formed in the
liquid ring pump. The shaft is in the first bore. A second bore is
formed in the pump and is axially inward of the first bore. A first
and second seal are in the second bore and around the shaft. The
second seal is axially outward of the first seal. The second seal
is the axially most outward seal in the bore. The second seal is
free of an abutment axially outward of it and abutting up against
it.
[0020] In a further example of the invention the second seal
includes a first sleeve and a second sleeve. The first and second
sleeves are coupled to one another and rotate relative to one
another. The shaft extends through an opening formed by the first
sleeve and contacts the first sleeve. The first sleeve is fixed
relative to the shaft and during operation of the pump rotates with
the shaft. The second sleeve contacts a surface of the pump which
forms the second bore, and during operation of the pump, the second
sleeve does not rotate relative to the surface of the pump it
contacts.
[0021] The invention further includes a method of retrofitting a
liquid ring pump. The liquid ring pump retrofit has a portion
having a bore formed therein. At least one seal is in the bore. The
seal is held in place by an abutment removeably coupled to the
portion of the pump forming the bore to overlap an axially outward
facing surface of the portion of the pump forming the bore. The
method includes removing the abutment holding said seal in place.
At least one seal is removed from the bore. A seal is placed in the
bore. The seal is placed in the bore axially outward of another
seal in the bore. The seal placed in the bore is left free of an
abutment axially outward of it and abutting up against it.
DETAILED DESCRIPTION
[0022] FIG. 2 discloses a liquid ring pump 210 embodying an example
of the present invention. The liquid ring pump shown in FIG. 2 has
many components that are the same as the liquid ring pump 10 shown
in FIG. 1. The components in FIGS. 2 and 3 that correspond to the
components of FIG. 1 have been labeled with the same numbers as
used in FIG. 1 except the prefix "2" has been added to each number.
Thus shaft 14 in FIG. 1 corresponds to shaft 214 in FIG. 2.
[0023] The pump of FIG. 2 has been retrofit with a composite seal
100 and a cassette seal 102. The composite seal and cassette seal
replace the first packing 54 in the first secondary bore 52 (first
stuffing box 52) and first gland 60 of FIG. 1. The composite seal
100 and cassette seal 102 are shown in FIGS. 2 and 3. To allow for
flow of liquid, during operation of the pump, into the first
secondary bore, a channel 104, has been bored through the first
head 236. The channel 104 opens up into the bore 252 at a first end
and opens up through the outward exterior surface 246 of the first
head 236 at a second end. The use of the composite seal 100 and
cassette seal 102 eliminates the need for the packing 54 and
packing gland 60. The cassette seal 102 is axially outward of the
composite seal 100 and abuts up against the composite seal 100. The
cassette seal 102 does not have a structure axially outward of it
which abuts up against it. Thus the axially outward most facing
surface 106 of the cassette seal 102 does not have a surface
abutting up against it. The seal arrangement 100, 102 remains fixed
from moving along the shaft in an axially outward direction without
the need for an axially outward abutment contacting the axial
outward surface 106 of the seal arrangement 100, 102. The abutment
eliminated includes a gland, end plate or flange coupled to the
housing to overlap the axially outward facing side 246 of the head
236 wherein the abutment would abut the axially most outward
surface 106 of the seal arrangement. The seal arrangement 100, 102
is prevented from moving in the axially inward direction by flanges
262. The composite seal 100 is fixed to the head 236 by a press fit
and it is within the bore 252. During operation, the rotor shaft
214 rotates within the composite seal 100. Liquid entering the bore
through channel 104 flows between the shaft 214 and the composite
seal 100. The liquid serves to lubricate the composite seal 100 and
seal out air and gas from entering the bore 252 from the working
chamber 234. The liquid exits the bore through a gap between the
internal surface 144 of the housing (head) forming the bore 252 and
the shaft 214.
[0024] To facilitate the flow of liquid between the composite seal
100 and the shaft 214, the seal 100 has grooves, through holes and
at least one slot therein. See FIG. 5. In more detail, the seal at,
a first axial end, has a first radially outer circumferential
groove 108 or channel along its outer surface. At the same axial
end it has a first radially inner circumferential groove 110 or
channel along its inner surface. The inner 110 and outer 108
grooves are radially opposite each other. The outer groove 108 is
bounded in the radially inward direction by a first circumferential
seal portion 112. The inner groove 110 is bounded in the radial
outward direction by the circumferential seal portion 112. A series
of through holes 114 extend through circumferential portion 112 to
fluidly connect the outer groove 108 to the inner groove 110.
[0025] The seal 100, at a second axial end, has a second radially
outer circumferential groove 116 or channel along its outer
surface. At the same second axial end, it has a second radially
inner circumferential groove 118 or channel along its inner
surface. The second inner 118 and second outer 116 grooves are
radially opposite each other. The second outer groove is bounded in
the radially inward direction by second circumferential seal
portion 120. The inner groove 118 is also bounded in the radial
outward direction by the second circumferential seal portion 120. A
series of through holes 122 extend through the second
circumferential seal portion 120 to fluidly connect the second
outer groove 116 to the second inner groove 118.
[0026] A series of axially extending channels 124 fluidly connect
the first inner circumferential channel 110 to the second inner
circumferential channel 118. The axially extending channels do not
extend through the composite seal. A slot 126 extends axially from
the first outer circumferential groove 108 and is fluidly connected
thereto. The slot 126 does not extend through the composite
seal.
[0027] As seen in FIGS. 3 and 4, the cassette seal 102 is more
generally a type of radial seal. The seal has a first sleeve 128.
The first sleeve 128 can be called a first circumferential ring.
The seal also has a second circumferential ring or second sleeve
130. The second sleeve 130 has a portion which encircles a portion
of the first sleeve. The first 128 and second 130 sleeves are
coupled to one another and rotate relative to one another. The
shaft 214 extends through an opening 132 formed by the first sleeve
and contacts the first sleeve. The first sleeve is fixed relative
to the shaft and during operation of the pump rotates with the
shaft. The first sleeve 128 thus rotates relative to the pump
housing 212 and more particularly relative to the first head 236.
The second sleeve 130 contacts a surface of the housing 212 which
forms the first secondary bore 252 and more particularly the
surface of the first head 236 which forms the surface defining bore
252. During operation of the pump, the second sleeve 130 does not
rotate relative to the housing 212 and first head 236. It is fixed
relative to the head 236 and housing 212. The first sleeve 128
rotates relative to the second sleeve 130.
[0028] The first circumferential ring or sleeve 128 has an axially
extending flange 134. The axially extending flange 134 forms a ring
or collar around the shaft 214. The shaft extends through the ring
128. The flange 134 includes an elastomeric material 136 facing
radially inward and contacting the shaft 214. The axially extending
flange 134 thus abuts up against the shaft in a fixed manner and
rotates with the shaft 214 during operation of the pump. The first
circumferential ring or sleeve 128 has a radially extending flange
137 extending from the axially extending flange 134. The radially
extending flange 137 forms the axially outward surface 106 bounding
the axial outward end of the first secondary bore (the first
stuffing box) 252. It provides the most axial outward surface of
the seal arrangement 100, 102. The cassette seal 102 and composite
seal 100 remain fixed from moving along the shaft 214 in an axially
outward direction without the need for an axial outward abutment
contacting the axial outward surface 106 of the cassette seal. The
abutment eliminated includes a gland, end plate or flange, coupled
to the housing to overlap an axially outward facing side 246 of the
head 236. The abutment eliminated would abut the axially most
outward surface 106 of the seal arrangement and cassette seal.
[0029] The second circumferential ring or sleeve 130 has an axially
extending flange 138. The axially extending flange 138 can be
called a second axially extending flange 138. The second axially
extending flange forms a ring or collar around the first axially
extending flange 134. The second flange 138 includes an elastomeric
material 140 facing radially outward and contacting the surface of
the first head 236 circumscribing the first stuffing box 252. The
second axially extending flange 138 thus abuts up against the head
236 in a fixed manner and does not rotate relative to the head 236
during operation of the pump and rotation of the shaft 214. The
second circumferential ring 130 has a radially extending flange 142
extending radially inward from the second axially extending flange
138. The radially extending flange 142 can be considered a second
radially extending flange 142. The second radially extending flange
142 is axially inward of the first radially extending flange 137.
During operation of the pump 210 and rotation of the shaft 214, the
first axially extending flange 134 rotates relative to the second
axially extending flange 138.
[0030] FIG. 6 discloses an alternative seal to that shown in FIG.
5. The seal 160 in FIG. 6 is similar to the seal 100 shown in FIG.
5. Similar portions have been labeled with the same numbers. The
primary difference between the seals in FIGS. 5 and 6 is that the
seal in FIG. 6 has a split extending radially through a section of
the seal. The split is bounded on one side by seal end 162 and the
other opposite side by seal end 164. The split allows for seal ends
162 and 164 to be pulled in opposite circumferential directions
apart from each other. Seal 160 is shown with the ends partially
pulled apart for clarity. A technician, to assemble the seal 100 to
the shaft 214, slides the seal onto the shaft 214 by way of the
split. The split thus facilitates assembly with the shaft. The seal
160 could have a coupling construction (not shown) to allow a
closing of the split at seal ends 162, 164 once the seal has been
assembled to the shaft. The cassette seal 102 could have a similar
split construction extending radially through a section of the
first and second sleeve.
[0031] Having described the construction, function and advantages
of the retrofit seal arrangement, for completeness, the
construction of the pump 210 shown in FIG. 2 is further described
below. FIG. 2 discloses a single stage liquid ring pump 210. The
pump has housing 212 with shaft 214 extending into the housing.
Rotor 216 is fixedly mounted to the shaft. The pump 210 has inlet
218 which leads into a gas intake zone 220. The pump has outlet 222
which leads out of the gas compression zone 224. During operation
of the pump the rotor 216 rotates in the housing 212. Air or gas
226 is drawn into the intake zone 220 through the inlet 218 and
into the buckets formed between adjacent rotor blades 228. As the
rotor rotates the operating liquid (not shown) fills the buckets
and the air or gas 226 is compressed and exits the pump through the
outlet 222.
[0032] The housing includes central portion 230 that has an
interior surface 232 that forms the cylindrical chamber 234 around
the rotor 216. The cylindrical chamber can also be called a working
chamber 234. The intake zone 220 and compression zone 224 form the
working chamber. The first head 236 is coupled to the first axial
end 238 of the central portion 230 and is at the first axial end of
the working chamber. The first head, which can also be called a
first cover, is at the outboard end of the liquid ring pump 210.
The housing has another cover 240 coupled to a second axial end 242
of the central portion 230. The cover 240, which can also be called
a second cover 240 or a power end cover 240, is at the second axial
end of the working chamber. The cover is at the power end of the
liquid ring pump. If the pump 210 were a two stage pump the cover
would be a second head. The central portion has an axis extending
in the axial direction. The shaft's longitudinal axis is parallel
to the central portion's axis extending in the axial direction. The
shaft's axis is offset, eccentric, relative to the central
portion's axis.
[0033] A first primary bearing support 244 is coupled to the
axially outward facing side 246 of the first head. A first primary
bore 248 is formed in the first bearing support 244. The shaft 214
extends into the first primary bore 248. A first primary bearing
assembly 250, which can also be called an outboard bearing
assembly, is disposed in the first primary bore 248 and around the
shaft 214. Axially inward of the first primary bearing assembly 250
is the first secondary bore 252. The first secondary bore 252 is
also called the first stuffing box 252. The first secondary bore
252 is formed in the first head 236. The shaft 214 extends through
the first secondary bore 252. The seal arrangement formed by the
cassette seal 102 and composite seal 100 is in the first secondary
bore 252 and around the shaft 214. A cone 284, coupled to the first
head 236, extends axially inward from an axially inward facing side
286 of the first head. The cone 284 is coupled to the first head
236. The cone extends into a complimentary bore formed by the rotor
216. Although the seal arrangement has been described as being
within a bore formed in the first head 236, it could alternatively
be in a bore formed by the cone 284 or a bore formed by the cone
284 and head 236. The shaft of course would extend through the
alternative bore.
[0034] A second primary bearing support 264 is coupled to an
axially outward facing side 266 of the power end cover 240. A
second primary bore 268 is formed in the second primary bearing
support 264. The shaft 214 extends into the second primary bore
268. A second primary bearing assembly 270, which can also be
called a power end bearing assembly, is disposed in the second
primary bore 268 and around the shaft 214. Axially inward of the
second primary bearing assembly 270 is a second secondary bore 272.
The second secondary bore can be called a second stuffing box 272.
The second secondary bore 272 is formed in the power end cover 240.
The shaft 214 extends through the second secondary bore 272. A
second packing 274 is in the second secondary bore 272 and around
the shaft 214. The packing includes seals 276 extending
circumferentially around the shaft 214. The seals are rope seals.
Axially between the rope seals is a lantern seal 278 which also
forms part of the packing. A packing gland 280, axially outward of
the packing 274, pushes and squeezes the packing axially inward to
abut up against flanges 282 that extend in the radial direction at
an axial inward end of the second secondary bore 272. The gland 280
abuts the packing. The gland is coupled, by fasteners 267, to the
head to overlap the axially outward facing side 266 of the power
end cover 240. The gland 280 fixes the packing and prevents the
packing from moving in the axial outward direction and holds the
packing in place. The packing and gland are fixed relative to the
cover 240. The packing is within the bore. The gland is partially
in the bore. The shaft 214 rotates within the packing 274 and
relative to the packing. The lantern seal 278 is fluidly connected
to a supply of liquid. The lantern seal 278 allows for liquid to
enter and be distributed between the packing 274 and shaft 214 to
provide lubrication and a sealing function to prevent escape of air
or gas from the working chamber 234 into the bore 272.
[0035] Although FIG. 2 depicts a pump with only a single first
retrofit seal arrangement and channel, it could also include or
alternatively have a retrofit seal arrangement and channel, like
the first retrofit seal arrangement and channel, replacing the
second packing 274 and gland 280 shown in FIG. 2.
[0036] Although the invention has been described in the context of
a conical liquid ring pump it is equally applicable to a flat sided
liquid ring pump.
[0037] The phrases "axially outward" and "axially inward" have
meanings which are ascertainable by their context. The phrase
axially inward can mean the relative location of one item compared
to another item. For example one item can be more towards the
center of the shaft along the axis than the other item. The phrase
axially outward can mean the relative location of one item compared
to another item. For example one item can be more away from the
center of the shaft along the axis than the other item.
[0038] The phrases "axial direction" and "radial direction" have
meanings which are ascertainable by their context. The phrase
axially direction can mean the direction relative to the axis of
the shaft. The phrase radial direction can mean the direction
relative to axis of the shaft.
[0039] All of the features disclosed in this specification
(including any accompanying claims, abstract and drawings), and/or
all of the steps of any method or process so disclosed, may be
combined in any combination, except combinations where at least
some of such features and/or steps are mutually exclusive.
[0040] Each feature disclosed in this specification (including any
accompanying claims, abstract and drawings) may be replaced by
alternative features serving the same, equivalent or similar
purpose, unless expressly stated otherwise. Thus, unless expressly
stated otherwise, each feature disclosed is one example only of a
generic series of equivalent or similar features.
[0041] The invention is not restricted to the details of the
foregoing embodiment(s). The invention extends to any novel one, or
any novel combination, of the features disclosed in this
specification (including any accompanying claims, abstract and
drawings), or to any novel one, or any novel combination, of the
steps of any method or process so disclosed.
* * * * *