Information
-
Patent Grant
-
6688601
-
Patent Number
6,688,601
-
Date Filed
Tuesday, November 20, 200122 years ago
-
Date Issued
Tuesday, February 10, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Knight; Anthony
- Kyle; Michael J.
Agents
-
CPC
-
US Classifications
Field of Search
US
- 277 358
- 277 372
- 277 393
- 277 425
- 277 547
- 277 548
-
International Classifications
-
Abstract
A mechanical seal includes a fixed ring, a rotating ring and a shaft sleeve. The fixed ring is connected in a sealed state to a housing. The rotating ring has a slide part and an engaging part. The slide part faces and slidably contacts with the fixed ring. The engaging part is provided for adapting drivingly to engage in a concave-convex manner. The shaft sleeve has a stop part adapted drivingly to engage with the engaging part without relative rotation, and fitted and stopped to the rotating shaft in the sealed state.
Description
FIELD OF THE INVENTION
This invention relates to a mechanical seal to be used as a shaft sealing means for a rotating machine such as a pump or the like.
DESCRIPTION OF THE RELATED ART
FIG. 4
shows a related art mechanical seal to be used as a shaft sealing means for large pumps. In
FIG. 4
, reference numeral
10
designates a housing of a shaft sealing part in a pump. A rotating shaft
20
is arranged in an inner circumference of the housing
10
so as to extend into a rotating machine. Numeral
30
designates a mechanical seal for sealing between the housing
10
and the rotating shaft
20
. The mechanical seal
30
comprises a seal cover
31
, sealing elements
32
, a shaft sleeve
33
, and sealing elements
34
. The seal cover
31
is attached to the outside end of the housing
10
. The sealing elements
32
at a stationary side are attached to the seal cover
31
. The shaft sleeve
33
is externally fitted to the rotating shaft
20
. The sealing elements
34
at a rotating side are attached to the shaft sleeve
33
.
The seal cover
31
is arranged at the outside end of the housing
10
, and is fixed by a bolt-nut
312
.
The sealing elements
32
comprise a bellows
321
and a seal ring
322
. The bellows
321
is arranged in an inner circumferential part of the seal cover
31
so as to extend into the machine. The seal ring
322
is sealed and fitted to a retainer
321
b
of its tip. The bellows
321
comprises, inside the seal cover
31
, an adapter
321
a
, the retainer
321
b
, and a bellows core
321
c
. The adapter
321
a
is attached together with a baffle sleeve
325
via a gasket
324
by a bolt
323
. The retainer
321
b
is arranged to the inside of the machine. The bellows core
321
c
is welded between the adapter
321
a
and the retainer
321
b.
On the other hand, the shaft sleeve
33
is fixed to the rotating shaft
20
by a setscrew
332
. The setscrew
332
is screwed in a radial direction from a sleeve collar
331
. The sleeve collar
331
is arranged in an outer circumference of an enlarged diameter part
33
a
. The enlarged diameter part
33
a
is formed on its end part to the outside of the machine. A packing
333
is interposed between the enlarged part
33
a
of the shaft sleeve
33
and the rotating shaft
20
. This packing
333
is appropriately pressed by a packing gland
335
. The packing gland
335
is given tightening force by a bolt
334
. The bolt
334
is screwed into the sleeve collar
331
.
A setscrew
332
is screwed in a radial direction from the sleeve collar
331
. The setscrew
332
penetrates the enlarged part
33
a
of the shaft sleeve
33
and the packing gland
335
. The setscrew
332
is fitted by a pressure to the outer circumferential surface of the rotating shaft
20
.
Further, the sealing elements
34
comprise a holder
342
and a mating ring
344
. The holder
342
is externally fitted to the inside end
33
b
of the shaft sleeve
33
via the packing
341
. The mating ring
344
is held by the holder
342
via a packing
343
. The mating ring
344
is adapted drivingly to engage in a circumferential direction with a pin
342
a
of the holder
342
at a cutout part
344
a
. The mating ring
344
is also sealed and contacted with the seal ring
322
of the sealing elements
32
by each opposite end face.
At a rear surface of the holder
342
, a collar
346
is attached via a bolt
345
. A pin
346
a
is provided in the circumferential part. The pin
346
a
adapts drivingly to engage in a radial direction with a cutout part
33
c
. The cutout part
33
c
is formed on the inside end
33
b
of the shaft sleeve
33
. Further, between an inner circumferential part of the collar
346
and an inner circumferential part of the holder
342
, two-divided press ring
348
is grasped together with the packing
341
and a spacer
347
pressing therewith. The inner circumferential part of the press ring
348
is fitted to a ring-like groove. The ring-like groove is formed on the outer circumferential surface of the inside end
33
b
of the shaft sleeve
33
. Thereby axial movement of the sealing elements
34
is limited relative to the shaft sleeve
33
.
That is, in the mechanical seal
30
, the end face of the seal ring
322
of the sealing elements
32
slidably contacts with the end face of the mating ring
344
of the sealing elements
34
by enforcement in an axial direction of the bellows
321
. Here the end face of the seal ring
322
is held in a non-rotating state with the seal cover that is attached to the housing
10
. The end surface of the mating ring
344
is rotated integrally with the rotating shaft
20
. Thereby it prevents a sealed fluid in the machine from flowing out from between the housing
10
and the rotating shaft
20
to the outside of the machine. At the sealing elements
34
, rotating force of the rotating shaft
20
is transmitted to the mating ring
344
via the shaft sleeve
33
, the collar
346
, the holder
342
, and the pin
342
a
. Here the shaft sleeve
33
is fixed to the rotating shaft
20
by the setscrew
332
. The collar
346
is adapted drivingly to engage with an inside cutout end
33
c
via a bin
346
a
. The holder
342
is connected by the bolt
345
. The pin
342
a
is provided on the holder
342
.
However, according to the above-described mechanical seal
30
, the mating ring
344
of the rotating side is constituted to fit to the ring-like recessed part of the holder
342
. Therefore, the size in the radial direction of the sealing elements
34
becomes in large. Accordingly, the large inner diameter of the housing
10
in the pump is necessary, which causes the large size of the whole machine. Further, the packing
343
is necessary for sealing between the mating ring
344
and the holder
342
. Therefore, this packing
343
needs high costs because of the large diameter.
Moreover, concerning the sealing elements
34
, the pin
342
a
and the cutout
344
a
are necessary for the holder
342
and the mating ring
344
as a rotation transmitting means. The collar
346
, the bolt
345
, the spacer
347
, and the pressing ring
348
or the like are necessary for the holder
342
as a fixing means in the axial direction. The pin
346
a
and the cutout part
33
c
are necessary for the collar
346
and the shaft sleeve
33
as a rotation transmitting means. Thus, these elements had complement forms and structures. Therefore, attachment work is so complicated that it takes long time, since the sealing elements
34
have the large number of elements.
Moreover, the sealing elements
34
need the large number of elements. If a few errors of the size or in attachment work were accumulated, the slide and contact position of the mating ring
344
largely slips off relative to the seal ring
322
, even if the attachment position of the shaft sleeve
33
is exact relative to the rotating shaft
20
. This leads possibly to generate large errors for the slide surface pressure.
SUMMERY OF THE INVENTION
The main object of the invention is to decrease the number of elements or parts to be used.
Another object of this invention is to provide a mechanical seal that can achieve its miniaturization and easy and rapid attachment work.
A mechanical seal according to one mode of this invention comprises a fixed ring connected in a sealed state to the housing and having a forcing means that is forced in an axial direction; a rotating ring having a slide part and an engaging part, wherein the slide part faces and slidably contacts with the fixed ring, and wherein the engaging part is formed for adapting drivingly to engage in a concave-convex manner; and a shaft sleeve fitted one end part in the sealed state to the rotating ring, holding the rotating ring in the axial direction, having a stop part adapted drivingly to engage with the engaging part without relative rotation, and fitted and stopped to the rotating shaft in the sealed state.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a semi sectional view showing a mechanical seal according to a preferred embodiment of the invention, which shows an attached state by cutting with a plane passing through a shaft center.
FIG. 2
is an exploded perspective view showing a mechanical seal according to a preferred embodiment of the invention, which shows an end part of the shaft center to the inside of the machine, a mating ring and a packing and a pressure ring attached thereto.
FIG. 3
is a semi sectional view showing a mechanical seal according to a preferred embodiment of the invention, which shows an unattached state by cutting with a plane passing through a shaft center.
FIG. 4
is a semi sectional view showing a related art mechanical seal, which shows an attached state by cutting with a plane passing through a shaft center.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1
is a semi sectional view of a mechanical seal according to a preferred embodiment of the invention, which shows an attached state by cutting with a plane passing through a shaft center. Reference numeral
50
designates a housing at a shaft sealing part. Numeral
60
designates a rotating shaft. The rotating shaft
60
is inserted in an inner circumference of the housing
50
. The rotating shaft
60
rotates a pumping mechanism as an impeller in the machine. Numeral
70
designates a mechanical seal according to the invention. The mechanical seal
70
comprises a seal cover
71
, stationary sealing elements
72
, a shaft sleeve
73
, and rotating sealing elements
74
. Here the seal cover is attached to the outside end of the housing
50
. The stationary sealing elements
72
are attached to the seal cover
71
at a stationary side. The shaft sleeve
73
is externally fitted to the rotating shaft
60
. The rotating sealing elements
74
are attached to the shaft sleeve
73
at a rotating side.
A seal cover
71
is arranged at the outside end of the housing
50
via a gasket
711
and is fixed by a bolt-nut means
712
. At the outside end of the inner circumferential part of the seal cover
71
, an outward protruding part
71
a
, an inward flange
71
b
inside thereof, and a cylindrical part
71
c
. The outward protruding part
71
a
can be adapted drivingly to engage with a setting jig
75
described below. The cylindrical part
71
c
extends to the inside of the machine therefrom.
The sealing elements
72
comprise a bellows
721
and a seal ring
722
. The bellows
721
is attached to the inner circumferential part of the seal cover
71
. The bellows
721
extends to the inside of the machine as a sealing means and enforcing means. The seal ring
722
is constituted as a fixed ring sealed and fitted to a retainer
721
b
of the movable end. The bellows
721
comprises an adapter
721
a
, a retainer
721
b
, and a bellows core
721
c
. The adapter
721
a
is connected in a sealed state by welding or brazing or the like to the inward flange part
71
b
of the seal cover
71
. The retainer
721
b
is movably arranged on the inner circumference of the inside end of the cylindrical part
71
c
of the seal cover
71
. The bellows core
721
c
is welded between the adapter
721
a
and the retainer
721
b
. Further, a circular damper
713
is attached on an inner circumferential surface of the cylindrical part
71
c
of the seal cover
71
. The circular damper
713
has a small space with the outer circumference of the bellows core
721
c
. Thereby vibration of the bellows
721
is prevented. Vibration of the sealing elements
72
is further prevented.
On the other hand, the shaft sleeve
73
is fixed to the rotating shaft
60
by a setscrew
732
. The setscrew
732
is screwed in a radial direction from a sleeve collar
731
. The sleeve collar
731
is arranged on the outer circumference of an enlarged part
73
a
. The enlarged part
73
a
is formed to the outside end of the machine. A packing
733
is interposed between the enlarged part
73
a
of the shaft sleeve
73
and the rotating shaft
60
. The packing
733
is appropriately pressed by a packing gland
735
. A tightening force is given to the packing gland
735
by a bolt
734
. The bolt
734
is screwed to the sleeve collar
731
. In the embodiment shown in the figure, the shaft sleeve
73
inserts one end part to an inside of a machine and has a tightening means
732
for tightening another end part at an outside of the machine.
Further, the setscrew
732
is screwed in a radial direction from the sleeve collar
731
. The setscrew
732
penetrates a hole
73
f
and a hole
735
b
for inserting the setscrew, and contacts by a pressure with the outer circumferential surface of the rotating shaft
60
. Here, the hole
73
f
is opened at the enlarged diameter part
73
a
of the shaft sleeve
73
. The hole
735
b
is opened at a cylinder part
735
a
of an inner circumference of the packing gland
735
. The cylinder part
735
a
is inserted in the inner circumference thereof. Further, on the outer circumferential surface of the sleeve collar
731
, one or more screw hole(s) (not shown in the figure) is/are formed in a circumferential direction for fixing a setting jig
75
described below.
The sealing elements
74
are externally fitted to the inside end of the shaft sleeve
73
. Further, it comprises a mating ring
741
, a packing
742
, a two-divided press ring
743
, and a stop ring
744
. The mating ring
741
is constituted as a rotating ring that is sealed and contacted with the seal ring
722
of the sealing elements
72
with its opposite end. The packing
742
seals between the shaft sleeve
73
and the mating ring
741
. The two-divided pressing ring
743
presses the packing
742
. The stop ring
744
stops from falling the mating ring
741
from the shaft sleeve
73
.
FIG. 2
is a perspective view showing the inside end of the shaft sleeve
73
, the mating ring
741
attached thereto, the packing
741
, and the pressing ring
743
. The mating ring
741
in a circumferential direction is partially shown in a sectional view.
As more clearly shown in
FIG. 2
, on the inside end of the shaft sleeve
73
, a plurality (four in the shown example) of engaging protrusions
73
b
are formed so as to extend in a axial direction at regular intervals in a circumferential direction. That is, a stop part
73
c
is formed between each engaging protrusion
73
b
. On the outer circumferential surface near the end of each engaging protrusion
73
b
, stop ring attachment grooves
73
d
are formed so as to extend in the circumferential direction at the positions corresponding to each other. Further, on the outer circumferential surface relative to the part formed of the engaging protrusions
73
b
, a groove
73
e
for attaching the press ring is formed in continuing in a circumferential direction. The groove
73
e
is positioned at the inner position compared to a slide part S with the seal ring
722
of the mating ring
741
.
In addition, the mating ring
741
forms a gradually tapered structure that forms an enlarged diameter of the outer circumferential surface to the side of the slide part S with the seal ring
722
. At the inside end of the inner circumferential surface, engaging protrusions
741
a
are formed in a circumferential direction at regular intervals. The engaging protrusions
741
a
are loosely fitted to the stop parts
73
c
between each engaging protrusion
73
b
of the shaft sleeve
73
. That is, the number of the engaging protrusions
741
a
is the same (four in the shown example) as the engaging protrusions
73
b
of the shaft sleeve
73
. Preferably, when the engaging parts
741
a
are fitted to the engaging protrusions
73
b
, the engaging parts
741
a
are stopped in the rotational and axial direction relative to the engaging protrusions
73
b
. In the embodiment shown in the figure, the stop part
73
c
is cut out at one end part in the axial direction and is formed plurally in a circumferential direction. Further, the engaging part
741
a
is formed so as to insert into the stop part
73
c
in the axial direction.
Further, the inner diameter of each engaging protrusion
741
a
of the mating ring
741
is set being able to loosely fit to the outer circumferential surface of the rotating shaft
60
. A diameter of inner circumferential surfaces
741
b
is set being able to loosely fit the outer circumferential surface of each engaging protrusion
73
b
of the shaft sleeve
71
. Here the engaging protrusions
741
a
are formed on the inner circumferential surfaces
741
b.
On the inner circumferential surface of the mating ring
741
, a step part
741
c
with an enlarged diameter is continuously formed in the circumferential direction at the outer side of the machine relative to the engaging protrusions
741
a
, that is, the side of the slide part S with the seal ring
722
. Further, a push ring
743
comprises a two-divided structure of semicircular divided particles
743
a
,
743
b
, and fitted to the groove
73
e
for attachment of the push ring of the shaft sleeve
73
. Thereby the outer circumferential surface is loosely fitted to an inner circumferential surface
741
d
of the larger diameter side (slide end surface side) of the step part
741
c
of the mating ring
741
. In addition, the packing
742
is arranged between the press ring
743
and the step part
741
c
. The packing
742
seals between the shaft sleeve
73
and the mating ring
741
.
Furthermore, reference numeral
71
d
in
FIG. 1
designates a flushing hole that is opened on the seal cover
71
. A line is connected for flowing back of one part of a fluid (a sealed fluid by the mechanical seal
70
). The fluid is send with pressure by an impeller (not shown) rotated by the rotating shaft
60
. That is, one part of the sealed fluid flows via the slide part S of the flushing hole
71
d
and through the outer circumferential space of the seal ring
722
and the mating ring
741
. Thereby heat of slide generated at the slide part S of the seal ring
722
and the mating ring
741
is effectively eliminated.
In the mechanical seal
70
having a constitution as explained above, the end surface of the seal ring
722
of the sealing elements
72
slidably contacts with the end surface of the mating ring
741
of the sealing elements
74
by enforcement in the axial direction of the bellows
721
. Here, the sealing elements
72
are held in a non-rotating state on the inner circumferential part of the seal cover
71
. The seal cover
71
is attached to the housing
50
. The sealing elements
74
are rotated integrally with the rotating shaft
60
. The slide part S is thus formed. Thereby, it is prevented that the sealed fluid in the machine flows out from between the housing
50
and the rotating shaft
60
to the outside of the machine. At this time, at the sealing elements
74
, rotating power of the rotating shaft
60
is transmitted from the shaft sleeve
73
to the mating ring
741
via a fitting surface of the engaging protrusions
73
b
and the engaging protrusions
741
a
. Here, the shaft sleeve
73
is fixed to the rotating shaft
60
by the setscrew
732
. The engaging protrusions
73
b
are formed on the inside end. The engaging protrusions
741
a
are formed on the inner circumferential surface of the mating ring
741
.
According to the mechanical seal
70
, the attachment position of the mating ring
741
in the axial direction relative to the shaft sleeve
73
is determined only by the stop ring
744
. Here the stop ring
744
is fitted to the grooves
73
d
of the shaft sleeve
73
. Therefore, an error of the attachment position in the axial direction of the mating ring
741
can be diminished. Further, since the mating ring
741
is directly engaged with the shaft sleeve
73
, the number of the elements is small compared to the prior one, which is attached by a holder or a collar. Thus, the size of the sealing elements
74
can be miniaturized in the axial and radial directions.
Further, in addition to the small number of the elements of the sealing elements
74
, the mating ring
741
is different from the prior one that is fitted to the holder. The packing with a large diameter is unnecessary for sealing such holder. Therefore, the cost of the elements can be lowered.
Further, since vibration of the bellows
721
at the sealing elements
72
is prevented by the dumper
713
that is attached to the inner circumferential surface of the cylindrical part
71
c
of the seal cover
71
, the structure at the stationary side can be simple.
FIG. 3
shows a state before installing the mechanical seal
70
to the housing
50
and the rotating shaft
60
. That is, in the mechanical seal
70
having the structure stated above, the sealing elements
72
comprises the bellows
721
and the seal ring
722
, and initially provides integrally with the inward flange part
71
b
of the inner circumference of the seal cover
71
.
The shaft sleeve
73
is arranged in the inner circumference of the sealing elements
72
. The packing
733
is arranged in the inner circumference of the enlarged part
73
a
that is formed to the outside end of the machine. Further, the cylinder part
735
a
of the packing gland
735
is inserted for holding the packing
733
from the outside. Further, the sleeve collar
731
is inserted in the enlarged diameter part
73
a
of the shaft sleeve
73
. Then, the screw hole
731
a
of the sleeve collar
731
, the hole
735
b
of the cylinder part
735
a
of the packing gland
735
, and the hole
73
f
of the enlarged diameter part
73
a
of the shaft sleeve
73
are piled each other in a radial direction. The setscrew
732
is inserted from the screw hole
731
a
of the sleeve collar
731
. Each tightening bolt
734
is screwed in the axial direction from a bolt insertion hole (not shown in the figure). The bolt insertion hole is opened on the outer circumferential flange part
735
c
of the packing gland
735
at certain intervals in the circumferential direction. Thereby, the shaft sleeve
73
, the packing gland
735
, and the sleeve collar
731
are temporarily connected each other.
Reference numeral
75
in
FIG. 3
designates a setting jig as a positioning means. At one end, a hook part
75
a
is formed to be hooked with the outward protruding part
71
a
that is formed on the seal cover
71
. At the other end part
75
b
, a hole for inserting a bolt (not shown in the figure) is opened. The bolt penetrates in a radial direction. At the inner circumference of the intermediate part, a spacer part
75
c
is formed, which is interposed between the outside end of the cylindrical part
71
c
and the sleeve collar
731
. Further, the hook part
75
a
of the setting jig
75
is engaged with the outward protruding part
71
a
of the seal cover
71
. The inner circumferential surface of the other end part
75
b
is piled on the outer circumferential surface of the sleeve collar
731
and fixed by a bolt
751
. Then, a relative position of the shaft sleeve
73
in the axial direction relative to the seal cover
71
is determined via the setting jig
75
and the sleeve collar
731
.
At the end part of the shaft sleeve
73
, the sealing elements
74
are installed. Here the end part of the shaft sleeve
73
reaches the inner side of the machine in respect to the seal ring
722
through the inner circumference of the sealing elements
72
. When installing the sealing elements
74
, the packing
742
is externally fitted to the outer circumferential surface between the engaging protrusions
73
b
of the shaft sleeve
73
and the groove
73
e
. Two divided push ring
743
is installed in the groove
73
. The mating ring
741
is externally fitted to the end part of the shaft sleeve
73
so that each engaging protrusion
741
a
is loosely fitted between each engaging protrusion
73
b
of the shaft sleeve
73
. Further, the stop ring
744
is installed to the grooves
73
d
that are formed over each engaging protrusion
73
b
of the shaft sleeve
73
. Thereby, the packing
742
and the push ring
743
are interposed with the inner circumferential surface
741
d
of the step part
741
c
at the large diameter side (the side of the slide part S). The mating ring
741
is installed to the shaft sleeve
73
in a state that its end face is contacted with the seal ring
722
.
The packing
742
may be held initially by the inner circumferential surface
74
d
at the large diameter side of the step part
741
c
of the mating ring
741
and be constituted so as to externally fit to the shaft sleeve
73
together with the mating ring
741
.
Further, a snap ring is used as the stop ring
744
, which has typically one discontinuous part in a circumferential direction, namely substantially C-shape. When each engaging protrusion
73
b
of the shaft sleeve
73
has some extent of elasticity in a radial direction, it may be constituted of a circular shape continuing in a circumferential direction.
In this state as explained above, the relative position of the shaft sleeve
73
in the axial direction relative to the seal cover
71
is determined via the setting jig
75
and the sleeve collar
731
. Therefore, relation between the sealing elements
72
and the sealing elements
74
is also determined. Here, the sealing elements are provided integrally with the seal cover
71
. The sealing elements are installed to the shaft sleeve. Therefore, as shown in
FIG. 3
, the bellows
721
at the sealing elements
72
is pressed in a certain axial direction. Thereby, the opposite faces of the seal ring
722
and the mating ring
741
are closely contacted each other by a certain surface pressure.
Next, the shaft sleeve
73
is then externally fitted to the rotating shaft
60
. The seal cover
71
is fixed to the outside end of the housing
50
by the bolt-nut
712
. The setscrew
732
is rotated in a fitting direction. Its top end contacts by a pressure with the outer circumferential surface of the rotating shaft
60
via the holes
73
f
,
735
b
. The holes
73
f
,
735
b
are opened at the enlarged diameter part
73
a
of the shaft sleeve
73
and the cylinder part
735
a
of the packing gland
735
. Thereby, the shaft sleeve
73
is fixed to the outer circumferential surface of the rotating shaft
60
via the sleeve collar
731
and the setting jig
75
in a state that the shaft sleeve
73
is positioned to the seal cover
71
.
Then, after fixing the seal cover
71
to the housing
50
and fixing the shaft sleeve
73
to the rotating shaft
60
, the setting jig is detached together with the bolt
751
, which is shown as an attachment condition in FIG.
1
.
That is, according to the mechanical seal
70
of the invention, the shaft sleeve
73
is initially positioned via the setting jig
75
and the sleeve collar
731
. Thereby it is installed to the housing
50
and the rotating shaft
60
in a state that the sealing elements
72
and the sealing elements
74
are positioned each other.
The hole
735
b
is formed in a long hole shape so as to extend in the axial direction. The hole
735
b
is opened at the cylinder part
735
a
of the packing gland
735
. After fixing the shaft sleeve
73
to the rotating shaft
60
by the sleeve collar
731
and the setscrew
732
, the packing gland
735
is movable in the axial direction by the fitting bolt
734
. Thus, the packing
733
can be pressed by a necessary and appropriate fitting force for sealing between the rotating shaft
60
and the shaft sleeve
73
.
According to the mechanical seal of the invention, the rotating ring has the engaging part for engaging in a concave-convex manner, and the shaft sleeve has the stop part adapted drivingly to engage the engaging part. Therefore, because both are connected, holder, collar, pin, bolt, and spacer etc. are unnecessary. Miniaturization is possible because the sealing elements at the rotational side are unnecessary.
Further, attachment work is simple because the stop part of the shaft sleeve can be inserted into the engaging part of the rotating ring in the axial direction. Miniaturization is further preceded because one end part of the shaft sleeve can be minimized in diameter.
Further, attachment and positioning work is quite simple because another end part of the shaft sleeve, which is opposed to the inserting position, can be tightened to the rotating shaft by the tightening means.
Claims
- 1. A mechanical seal, comprising:a housing; a plurality of stationary sealing elements including a fixed ring fixed in a rotating direction relative to the housing and means for biasing the fixed ring in an axial direction; a rotary shaft located in the housing; a shaft sleeve fixed to the rotary shaft in a sealed state; a plurality of rotary sealing elements including a rotary ring provided on an outer circumference of the shaft sleeve in a sealed sate so as to rotate together with the rotary shaft, wherein the rotary ring contacts the fixed ring and has an engaging part for engaging the shaft sleeve in a non-rotating state; and means for stopping the rotary ring in the axial direction, wherein the stopping means includes a stop ring and a two part push ring attached in a groove formed on an outer periphery of the shaft sleeve, wherein the stationary sealing elements are provided on a seal cover that is attached in a sealed state to the housing, and the two part push ring including semicircular divided pieces.
- 2. A mechanical seal according to claim 1, wherein the engaging part of the rotary ring has an engaging protrusion and the shaft sleeve has an engaging protrusion, wherein the engaging protrusion of the rotary ring is formed on an inner circumferential surface of the rotary ring, and wherein the engaging protrusion of the shaft sleeve is formed on an end part of the shaft sleeve so as to engage the engaging protrusion.
- 3. A mechanical seal according to claim 2, wherein a stop groove is formed on the engaging protrusion of the shaft sleeve and wherein the ring is fitted in the stop groove.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2000-353856 |
Nov 2000 |
JP |
|
US Referenced Citations (10)