U.S. patent application number 11/875361 was filed with the patent office on 2008-02-21 for electric rotating machine.
Invention is credited to Yutaka HASHIBA, Takeshi Hayashi, Yasuo Kabata, Yukihiko Kazao, Makoto Mikami, Ikuo Saito, Hidekazu Shiomi, Yoshihiro Taniyama.
Application Number | 20080042363 11/875361 |
Document ID | / |
Family ID | 32314084 |
Filed Date | 2008-02-21 |
United States Patent
Application |
20080042363 |
Kind Code |
A1 |
HASHIBA; Yutaka ; et
al. |
February 21, 2008 |
ELECTRIC ROTATING MACHINE
Abstract
Hydrogen gas is circulated to cool an electric rotating machine
main body, and brush seals are provided to contact a predetermined
position on the outer circumferential surface of a rotating shaft.
As a result, contact of a sealing oil and the hydrogen gas, contact
of a lubricating oil and the sealing oil in the bearing, and
leakage of the hydrogen gas outside the machine are prevented.
Inventors: |
HASHIBA; Yutaka;
(Yokosuka-shi, JP) ; Mikami; Makoto; (Tokyo,
JP) ; Hayashi; Takeshi; (Yokohama-shi, JP) ;
Kazao; Yukihiko; (Yokohama-shi, JP) ; Saito;
Ikuo; (Yokohama-shi, JP) ; Shiomi; Hidekazu;
(Chiba-shi, JP) ; Taniyama; Yoshihiro; (Tokyo,
JP) ; Kabata; Yasuo; (Yokohama-shi, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Family ID: |
32314084 |
Appl. No.: |
11/875361 |
Filed: |
October 19, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11128368 |
May 13, 2005 |
7291947 |
|
|
11875361 |
Oct 19, 2007 |
|
|
|
PCT/JP03/14481 |
Nov 13, 2003 |
|
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|
11128368 |
May 13, 2005 |
|
|
|
Current U.S.
Class: |
277/355 |
Current CPC
Class: |
F16J 15/3288 20130101;
F16J 15/442 20130101; H02K 9/20 20130101; H02K 5/124 20130101; H02K
5/1672 20130101; H02K 9/19 20130101; F16J 15/26 20130101; H02K 9/10
20130101; F16J 15/443 20130101; F16J 15/441 20130101 |
Class at
Publication: |
277/355 |
International
Class: |
F16J 15/44 20060101
F16J015/44 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 13, 2002 |
JP |
2002-329168 |
Mar 5, 2003 |
JP |
2003-058273 |
Claims
1. An electric rotating machine comprising: a bearing device which
rotatably supports a rotating shaft configures a rotor inside a
frame which contains an electric rotating machine main body; a
cooling medium system which supplies a cooling medium within the
frame to cool the electric rotating machine main body; a brush
holder which is mounted on at least one of inner and outer part of
the frame, and forms a predetermined storage space by surrounding
the outer circumferential side of the rotating shaft; a brush
sealing mechanism main body which comprises: a circular ring shaped
brush seal which is in the brush holder and contained such that a
plurality of stages are formed in the axial direction of the
rotating shaft, each stage contacting the rotating shaft; and a
support portion for supporting the brush seal at each of the
reverse rotating shaft sides, each of the brush seals having a
plurality of divisions in the radial direction along the axial
direction, the position of the division of each stage of adjacent
brush seals being offset, and no cooling medium in the frame
leaking to the outer portion of the frame; and a drop prevention
member which prevents the brush seal in the brush holder from
dropping in the axial direction due to a pressure difference
between the cooling medium and outside the frame.
2. The electric rotating machine according to claim 1, further
comprising an adjustment mechanism in which a push amount of the
drop prevention member is adjustable.
3. The electric rotating machine according to claim 1, further
comprising a spacing member inside the brush holder and between the
brush seals.
4. The electric rotating machine according to claim 1, further
comprising a mechanism to align the brush holder in the
circumferential direction of the rotating shaft inside the
frame.
5. The electric rotating machine according to claim 1, further
comprising a gap sensor which measures a gap between the brush
holder and the brush and between the brush holder and the rotating
shaft, wherein a displacement amount of the mechanism for automatic
alignment is automatically adjusted by using an output of the gap
sensor.
6. The electric rotating machine according to claim 1, wherein
brush type contact seal devices each formed of the brush holder and
the brush seal mechanism main body is provided at least two
locations along the axial direction of the rotating shaft, and
purge oil is supplied between the brush type contact seal devices.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This present application is a Divisional Application of
application Ser. No. 11/128,368 filed May 13, 2005, which is a
Continuation Application of PCT Application No. PCT/JP03/14481,
filed Nov. 13, 2003, which was published under PCT Article 21(2) in
Japanese.
[0002] This application is based upon and claims the benefit of
priority from prior Japanese Patent Applications No. 2002-329168,
filed Nov. 13, 2002; and No. 2003-058273, filed Mar. 5, 2003, the
entire contents of both of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to an electric rotating
machine comprising a shaft seal device which cools an electric
rotating machine main body with a cooling medium such as hydrogen
gas and which seals a shaft through portion.
[0005] 2. Description of the Related Art
[0006] In a large capacity turbine generator, for example,
pressurized hydrogen gas is sealed inside the machine, and a rotor
and a stator which configure a generator main body (electric
rotating machine main body) are cooled using the hydrogen gas.
Because the hydrogen gas has lower density and higher specific heat
capacity than air, hydrogen-cooled generator can operate in high
efficiency. Therefore, many large capacity turbine generators use
this cooling system. In such a hydrogen-cooled generator, shaft
seal devices for preventing leakage of the hydrogen gas inside the
machine, from bearings to the outside are installed at both ends of
the generator (see (Prior art publication 1: Jpn. Pat. Appln. KOKAI
Publication No. 7-75291) and (Prior art publication 2: Jpn. Pat.
Appln. KOKAI Publication No. 10-14158)).
[0007] Now, a conventional shaft seal device will be explained with
reference to the drawings. FIG. 28 is a cross-sectional view of an
end of an electric rotating machine in the vicinity of a shaft seal
device 99 that seals hydrogen the inside of a machine in a
conventional hydrogen-cooled electric rotating machine. Reference
numeral 1 is a stator frame which has a cylindrical shape, and at
an end thereof, an end bracket 3 is fixed via a stator frame end
plate 2. A bearing bracket 4 is fixed on the end bracket 3, a
bearing stand 5 is attached inside the bearing bracket 4, and a
bearing device (bearing) 6 is attached inside the bearing stand 5.
The bearing 6 supports a rotating shaft (shaft) 7 to be
rotatable.
[0008] A seal casing 9 and a seal ring 10 which configure the shaft
seal device 99 are provided to seal hydrogen gas 8 inside the
machine that is enclosed by the stator frame 1, the stator frame
end plate 2, the end bracket 3 and the like not to leak from a gap
formed with the rotating shaft 7 which rotates due to the movement
of the electric rotating machine. In addition, oil deflectors 11
and 12 are provided inside the machine and outside the machine,
respectively, such that a lubricating oil used in the shaft seal
device 99 and the bearing 6 does not leak, and a space called a
seal cavity 13 is provided between the internal oil thrower 12 and
the shaft seal device 99.
[0009] FIG. 29 is an enlarged view showing the details of the seal
casing 9 and the seal ring 10 which configure the shaft seal device
99. In FIG. 29, the seal ring 10 comprises two seal rings 10A and
10B which are aligned in the axial direction, and each of the seal
rings is processed such that the inner diameter is slightly larger
than the outer diameter of the rotating shaft 7.
[0010] Seal oil 17 is supplied from the seal casing 9 with slightly
higher pressure than the gas pressure of the hydrogen gas for
generator cooling. The sealing oil 17 is supplied to a narrow gap
19 which is formed by the seal rings 10A and 10B and the rotating
shaft 7 via an axial direction gap 18 between the seal ring 10A and
10B. By forming an oil film here, leakage of the hydrogen gas 8
inside the machine to the outside the machine is prevented. A
spring 20 presses the seal rings 10A and 10B, and adjusts a
circumferential direction gap 19 between the rotating shaft 7 and
the seal ring 10A and 10B.
[0011] FIG. 30 is a cross-sectional view along the arrow 30-30 in
FIG. 29, and the seal ring 10B is formed of a seal ring upper half
portion 10Ba and a seal ring lower half portion 10Bb which form a
radial arc in the axial direction with respect to the rotating
shaft 7. The seal ring 10A is same as the seal ring 10B.
[0012] The spring 20 is fixed by screws 20a provided in the seal
casing 9. The spring 20 is disposed in an annular state along the
joint between the seal ring 10A and the seal ring 10B, and forms
the circumferential direction gap 19 with the rotating shaft 7 with
an optimal pressing force. An optimal amount of oil is supplied by
adjusting the circumferential direction gap 19 to fill the
circumferential direction gap 19 with the sealing oil 17 and the
hydrogen gas 8 can be sealed inside the machine.
[0013] The sealing oil 17 which has flowed outward from the
circumferential direction gap 19 flows to the seal cavity 13 side
and the bearing device side. The sealing oil 17 which has flowed
outward to the seal cavity 13 side is recovered alone or
alternatively, the sealing oil which has flowed out to the bearing
device side is recovered together with the lubricating oil from the
bearing device 6. Each of the oils recovered are combined again
after collection, and as shown in FIG. 31, they are pressurized
using a pressure pump 59 and sent to the shaft seal device and the
bearing device, respectively. However, the sealing oil 17 which has
flowed from the circumferential direction gap 19 to the bearing
device 6 side and the lubricating oil from the bearing device are
surrounded by air, and thus return to the pressure pump 59 in a
state in which air is mixed in the oil. Because the oils are sent
to the shaft seal device after pressure is applied, part of the air
mixed into the sealing oil 17 that has flowed from the
circumferential direction gap 19 to the seal cavity 13 side blows
out to the seal cavity 13 side. Instead, the hydrogen gas 13 inside
the machine which is inside the seal cavity 13 is mixed with the
seal oil 17 and discharged outside the machine. The air blown into
the seal cavity 13 replaces the hydrogen gas 8 inside the machine
via the gap between the deflector 12 and the rotating shaft 7, and
as a result, the purity of the hydrogen gas 8 inside the machine is
lowered.
[0014] In order to avoid this, in the typical shaft seal device,
the oils are subjected to degassing in a degassing device 58 before
entering the pressure pump 59, and the oils are supplied to the
shaft seal device or the bearing device 6 in a state in which gas
such as the cooling hydrogen gas 8 or air is not mixed in the
oils.
[0015] However, the suction processing device 58 is of a
comparatively high cost, and this is one factor causing increased
cost for the electric rotating machine in which hydrogen gas or the
like is used as the cooling medium.
[0016] It is to be noted that in FIG. 31, aside from the
above-described configuration, the dynamo-electrical machine main
body may be contained in the frame or it may comprise a hydrogen
extracting device 55 which extracts hydrogen gas circulating in a
circulating system (not shown), an air extracting device 56 for
extracting air from the lubricating oil in the shaft seal device 6,
a lubricating oil system 57 for sending the lubricating oil from
which air has been removed to the degassing device 58 and the
bearing device 6.
[0017] Aside from the prior art example of the shaft seal device
described above, there is also a non-contact type sealing device
configured as follows. As shown in, for example, FIG. 28, the seal
ring 10 is contained inside the seal casing 9 attached to the end
bracket 22, and the spring 20 is supported so as to form a narrow
gap between itself and the rotating shaft 7. The seal rings 10 are
arranged in 2 rows in the axial direction of the rotating shaft 7,
and oil of a pressure that is slightly higher than the gas pressure
inside the machine is supplied from the outside to the gap between
the sealing 10 and the rotating shaft 7. The pressure oil passes
through the gap, and the gas inside the machine is sealed due to
the formation of leaking oil as shown by the arrow in FIG. 29. In
this type of configuration, because the seal ring 10, the seal
casing 9 and the rotating shaft 7 etc. are thermally deformed in a
complex manner during operation, the seal oil amount (purge oil
amount) may exceed a design value and sometimes increases more than
expected in transition (particularly at the time of startup).
Furthermore, the thickness of the oil film decreases locally due to
deformation, and vibration is caused by the frictional force of
that portion. In recent years, development of a brush type contact
seal for solving these problems has been progressing, and this is
being used as an air seal for a gas turbine or steam turbine, a
liquid seal for low pressure difference, or a dust-protective seal.
However, in a liquid seal for high pressure difference using a
liquid as the sealing medium (purge oil), such as in a gas sealing
inside the turbine generator, sufficient sealing properties can not
be obtained, and further, a large amount of sealing oil is
necessary.
[0018] Aside from the prior arts described above, there are also
Prior art publication 3 (Jpn. Pat. Appln. KOKAI Publication No.
2002-81552), Prior art publication 4 (Jpn. Pat. Appln. KOKAI
Publication No. 2003-161108), Prior art publication 5 (Jpn. Pat.
Appln. KOKAI Publication No. 2002-303371) and Prior art publication
6 (Jpn. Pat. Appln. KOKAI Publication No. 2001-90842).
[0019] In Prior art publication 3, a rotating body like a rotating
shaft has an improved brush sealing device which is provided at a
portion that penetrates a pressure partition wall and is described
as follows. That is, this example describes the brush seal device
having a structure with "a plurality of brush seal segments that
are divided in the circumferential direction", in order to
disassemble the device and to facilitate the removal of the
internal rotating shaft at the time of manufacture, or at the time
of inspection after operation has begun. However, there is no
description of any measures for dealing with possible dropping of
the brush seal due to the pressure of the leaking oil.
[0020] Prior art publication 4 merely describes a structure for
facilitating attachment and removal in the installation method for
a sealing device and for preventing installation error. In this
sealing device, a labyrinth seal is used together with a brush seal
in order to improve the sealing properties of the rotating shaft in
a turbo device having a labyrinth seal.
[0021] Prior art publication 4 is a labyrinth seal, and the
labyrinth seal is a sealing mechanism which suppresses the leakage
of fluid from the high pressure side to the low pressure side with
the labyrinth seal interposed therebetween, and is different from
the oil deflector which is disposed with the bearing interposed
therebetween. Basically, in the oil deflector, the fluid pressure
at both sides where the oil deflector is nipped is the same and it
does not limit the amount of fluid leakage. In addition, the
purpose of the oil deflector is to prevent or suppress the leakage
of mist oil or liquid oil and it is thus different from the
labyrinth seal.
[0022] Meanwhile, in the Prior art publication 4, operational
effects of the labyrinth seal are described in which sealing
properties are improved by providing a back plate at the high
pressure side of the labyrinth seal and at the low pressure side of
the brush seal, or alternatively, the sealing properties are
improved by attaching a brush seal to both sides of the labyrinth
seal, but this is different from the oil deflector.
[0023] The Prior art publication 5 describes a device in which oil
mist (oil particles in a mist-like state) is sealed in a bearing
cavity. In order to seal the oil mist that is generated in the
bearing cavity inside the bearing cavity, the bearing cavity may be
attached to one side of the bearing housing or at the side surfaces
at both sides. Thus, while Prior art publication 5 seals oil mist
(oil particles in a mist-like state) inside the bearing cavity, one
is the type in which the liquid oil (usually called side leak) that
is blown out from the side surface of the bearing and the sealing
oil of the shaft seal device that uses the oil which seals the gas
inside the machine are separated (not caused to contact each
other), and the other one is the type in which all the oils used in
the machine (sealing oil and bearing oil) are cut-off so as not to
contact the outside air. Thus, both types are not necessarily
provided at the bearing side surface.
[0024] Prior art publication 6 describes that a special kind of
brush (in which extremely fine fibers are woven) is used to reduce
the leakage of fluid, and there is no abnormal charge which is
different from that of a metal brush, and no breakage as in the
case of the metal brush and the ceramic brush. However, the brush
seal that uses this special kind of brush is attached to a machine
having a pressure difference between the inside and the outside the
machine, and it clearly different from one that basically does not
seal a pressure difference.
BRIEF SUMMARY OF THE INVENTION
[0025] A first object of the invention is to provide an electric
rotating machine which comprises a shaft seal device capable of
preventing contact of cooling gas and sealing oil and suppressing
the reduction in purity of the cooling gas inside the machine
without degassing of the sealing oil.
[0026] A second object of the invention is to provide an electric
rotating machine in which a small amount of oil is sufficient for
all operating conditions from startup to regular rotation and there
is no excessive change in oil quantity, the electric rotating
machine further comprising a highly pressure resistant brush type
contact sealing device which has excellent vibration stability.
[0027] A third object of the invention is to provide an electric
rotating machine, in which purity of the cooling medium in the
machine is not lowered, and it is unnecessary to suction the
sealing medium before feeding, the electric rotating machine
comprising a low-cost shaft seal device which does not require a
degassing device.
[0028] To achieve abovementioned subject matter, an electric
rotating machine according the first aspect of the invention,
comprises: a bearing device which rotatably supports a rotating
shaft configures a rotor in a frame containing an electric rotating
machine main body; a cooling medium circulating system to circulate
a cooling medium within the frame to cool the electric rotating
machine main body; a seal ring device which supplies a sealing
medium to the outer circumferential surface side of the rotating
shaft, and prevents the cooling medium from leaking to outside the
frame; a sealing mechanism which is arranged to contact an outer
circumferential surface of the rotating shaft, and prevents the
cooling medium and the sealing medium, or the sealing medium and/or
a lubricating medium inside the bearing device from contacting the
outside air.
[0029] To achieve abovementioned subject matter, an electric
rotating machine according the second aspect of the invention,
comprises: a bearing device in which a rotating shaft having a
rotor is rotatably supported inside a frame which contains an
electric rotating machine main body; a cooling medium circulating
system to circulate a cooling medium within the frame to cool the
electric rotating machine main body; an oil deflector which is
disposed on an outer circumferential surface of the rotating shaft
which is on at least one of the inner side and the outer side of
the frame of the bearing device and which prevents a lubricant
supplied to the bearing device from flowing inside the frame or
from flowing outside the frame; a sealing device which is disposed
to form a cavity inside the frame and between the bearing device
and the oil deflector at the inner side of the frame, and which
supplies a sealing medium to the outer circumferential surface side
of the rotating shaft to prevent the cooling medium from leaking to
the outer side of the frame; and a sealing mechanism which is
arranged to contact the outer circumferential surface of the
rotating shaft, and which prevents the cooling medium and a medium
within the seal cavity, or the cooling medium and the sealing
medium or the sealing medium and/or a lubricating medium inside the
bearing device from contacting the outside air.
[0030] To achieve abovementioned subject matter, an electric
rotating machine according the third aspect of the invention,
comprises: a bearing device which rotatably supports a rotating
shaft configures a rotor inside a frame which contains an electric
rotating machine main body; a cooling medium system which supplies
a cooling medium within the frame to cool the electric rotating
machine main body; a brush holder which is mounted on at least one
of inner and outer part of the frame, and forms a predetermined
storage space by surrounding the outer circumferential side of the
rotating shaft; a brush sealing mechanism main body which
comprises: a circular ring shaped brush seal which is in the brush
holder and contained such that a plurality of stages are formed in
the axial direction of the rotating shaft, each stage contacting
the rotating shaft; and a support portion for supporting the brush
seal at each of the reverse rotating shaft sides, each of the brush
seals having a plurality of divisions in the radial direction along
the axial direction, the position of the division of each stage of
adjacent brush seals being offset, and no cooling medium in the
frame leaking to the outer portion of the frame; and a drop
prevention member which prevents the brush seal in the brush holder
from dropping in the axial direction due to a pressure difference
between the cooling medium and outside the frame.
[0031] To achieve abovementioned subject matter, an electric
rotating machine according the fourth aspect of the invention,
comprises: a bearing device which rotatably supports a rotating
shaft configuring a rotor inside a frame which contains an electric
rotating machine main body; a lubricating medium circulating system
to circulate a lubricating medium in the bearing device; a cooling
medium circulating system to circulate a cooling medium within the
frame to cooling the electric rotating machine main body; an oil
deflector which is disposed on the outer circumferential surface of
the rotating shaft which is on the inner side and/or the outer side
of the frame of the bearing device and prevents a lubricant that is
supplied to the bearing device from flowing inside the frame or
from flowing outside the frame; a seal ring device which is
disposed inside the frame further toward inside the machine than
the bearing device, supplies a sealing medium to the outer
circumferential surface side of the rotating shaft, and prevents
the cooling medium from leaking to the outer side of the frame; and
a sealing mechanism which is formed of a brush seal to contact the
outer circumferential surface of the rotating shaft, and prevents
the sealing medium and the lubricating medium from contacting each
other.
[0032] To achieve abovementioned subject matter, an electric
rotating machine according the fifth aspect of the invention,
comprises: a bearing device which rotatably supports a rotating
shaft configuring a rotor inside a frame which contains an electric
rotating machine main body; a lubricating medium circulating system
which circulates a lubricating medium in the bearing; a cooling
medium circulating system which circulates a cooling medium in the
frame to cool the electric rotating machine main body; an oil
deflector which is disposed to contact the outer circumferential
surface of the rotating shaft which is on the inner side and/or the
outer side of a frame of the bearing device, and prevents a
lubricant that is supplied to the bearing device from flowing
inside the frame or from flowing outside the frame; and a sealing
mechanism which positioned at out side of the bearing or at outer
side from the bearing, includes configuration including a brush
seal to contact the outer circumferential surface of the rotating
shaft, and prevents the sealing medium and the outside air from
contacting each other.
[0033] To achieve abovementioned subject matter, an electric
rotating machine according the sixth aspect of the invention,
comprises: a bearing device which rotatably supports a rotating
shaft configuring a rotor inside a frame which contains an electric
rotating machine main body; a lubricating medium circulating system
to circulate a lubricating medium in the bearing device; a cooling
medium circulating system to circulate a cooling medium within the
frame to cool the electric rotating machine main body; an oil
deflector which is disposed on the outer circumferential surface of
the rotating shaft which is on the inner side and/or the outer side
of the frame of the bearing device, and prevents a lubricant that
is supplied to the bearing device from flowing inside the frame
from flowing outside the frame; a seal ring device which is
disposed inside the frame further toward the inner frame than the
bearing device, and supplies sealing medium to the outer
circumferential surface side of the rotating shaft and prevents the
cooling medium from leaking to the outer side of the frame; and a
sealing mechanism which is inside the frame of the bearing device,
is formed of a brush seal to contact the outer circumferential
surface of the rotating shaft, prevents the cooling medium and the
lubricating medium in the bearing device from contacting each other
and prevents the cooling medium from leaking to outer side of the
machine.
[0034] To achieve abovementioned subject matter, an electric
rotating machine according the seventh aspect of the invention,
comprises: a bearing device which rotatably supports a rotating
shaft configuring a rotor inside a frame which contains an electric
rotating machine main body; a lubricating medium circulating system
to circulate a lubricating medium in the bearing device; a cooling
medium circulating system to circulate a cooling medium within the
frame to cool the electric rotating machine main body; an oil
deflector which is disposed on the outer circumferential surface of
the rotating shaft which is on the inner side and/or the outer side
of the frame of the bearing device, and which prevents a lubricant
that is supplied to the bearing device from flowing inside the
frame or from flowing outside the frame; and a sealing mechanism
which is outside the frame of the bearing device, is formed of a
brush seal to contact the outer circumferential surface of the
rotating shaft, and prevents the lubricating medium and the sealing
medium in the bearing device from contacting each other.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0035] FIG. 1 is a cross-sectional view showing an end of an
electric rotating machine comprising a shaft seal device according
to a first embodiment of the invention.
[0036] FIG. 2 is a cross-sectional view showing a shaft seal device
of an electric rotating machine according to a second embodiment of
the invention.
[0037] FIG. 3 is a cross-sectional view showing an end of an
electric rotating machine comprising a shaft seal device according
to a third embodiment of the invention.
[0038] FIG. 4 is a cross-sectional view showing a shaft seal device
of an electric rotating machine according to a fourth embodiment of
the invention.
[0039] FIG. 5 is a cross-sectional view showing a shaft seal device
of an electric rotating machine according to a fifth embodiment of
the invention.
[0040] FIG. 6 is a cross-sectional view showing a shaft seal device
of an electric rotating machine according to a sixth embodiment of
the invention.
[0041] FIG. 7 is a view showing a schematic configuration according
to a seventh embodiment of the invention.
[0042] FIGS. 8A and 8B are views each showing a front surface
configuration of a brush according to the seventh embodiment shown
in FIG. 7.
[0043] FIG. 9 is an explanatory view showing a drop prevention
method for brushes according to an eight embodiment of the
invention.
[0044] FIG. 10 is an explanatory view showing another drop
prevention method for brushes according to the eight embodiment of
the invention shown in FIG. 9.
[0045] FIG. 11 is an explanatory view showing means for covering a
gap between brushes according to a ninth embodiment of the
invention.
[0046] FIG. 12 shows tenth embodiment and is an explanatory view
showing another means for covering the gap between the brushes
according to the ninth embodiment shown in FIG. 11.
[0047] FIG. 13 is an explanatory view showing means for maintaining
a concentric state of a rotating shaft and a brush according to a
eleventh embodiment of the invention.
[0048] FIG. 14 shows twelfth embodiment and is an explanatory view
showing another means for maintaining the concentric state of the
rotating shaft and the brush according to the tenth embodiment
shown in FIG. 14.
[0049] FIG. 15 shows thirteenth embodiment and is an explanatory
view showing a method of externally controlling the rotating shaft
and the brush to be maintained in a concentric state according to
the tenth embodiment of the invention shown in FIGS. 13 and 14.
[0050] FIG. 16 shows fourteenth embodiment and is an explanatory
view another method of externally controlling the rotating shaft
and the brush to be maintained in a concentric state according to
the tenth embodiment of the invention shown in FIGS. 13 to 15.
[0051] FIG. 17 shows a fifteenth embodiment of the invention and a
configuration which shows a method of applying a brush type contact
seal to a turbine generator.
[0052] FIG. 18 shows the fifteenth embodiment shown in FIG. 17 and
a structure when the brush type contact seal is applied to the
turbine generator.
[0053] FIG. 19 shows the sixteenth embodiment and the structure
when the brush type contact seal is applied to the turbine
generator.
[0054] FIG. 20 is an axial direction cross-sectional view of an
area around a shaft seal device according to a seventeenth
embodiment of the invention.
[0055] FIG. 21 is an axial direction cross-sectional view of the
area around the shaft seal device according to a modification of
the seventeenth embodiment of the invention.
[0056] FIG. 22 is an axial direction cross-sectional view of an
area around a shaft seal device according to an eighteenth
embodiment of the invention.
[0057] FIG. 23 is an axial direction cross-sectional view of the
area around the shaft seal device according to a modification of
the eighteenth embodiment of the invention.
[0058] FIG. 24 is an axial direction cross-sectional view of the
area around the shaft seal device according to another modification
of the eighteenth embodiment of the invention.
[0059] FIG. 25 is an axial direction cross-sectional view of an
area around a shaft seal device according to another modification
of the eighteenth embodiment of the invention.
[0060] FIG. 26 is an axial direction cross-sectional view of an
area around a shaft seal device according to a nineteenth
embodiment of the invention.
[0061] FIG. 27 is an axial direction cross-sectional view of an
area around a shaft seal device according to another embodiment of
the nineteenth embodiment of the invention.
[0062] FIG. 28 is a cross-sectional view of the conventional shaft
seal device.
[0063] FIG. 29 is a cross-sectional view in which a seal casing
portion of FIG. 28 is enlarged.
[0064] FIG. 30 is a cross-sectional view taken along line 30-30 in
FIG. 29 when viewed in the direction of the arrow.
[0065] FIG. 31 is a pipeline system drawing of a bearing device and
a sealing medium of the conventional electric rotating machine.
DETAILED DESCRIPTION OF THE INVENTION
[0066] Now, embodiments of an electric rotating machine including a
shaft seal device according to the invention will be explained with
reference to the drawings. FIG. 1 is an axial direction
cross-sectional view of an area around a shaft seal device of an
electric rotating machine showing a first embodiment of the
invention, and it differs from FIG. 28 which shows the prior art
described above, in that a brush seal 21 serving as a sealing
mechanism which does not require a lubricating member formed of a
seal brush is provided at a seal cavity 13 of an internal oil
deflector 12. In other words, in this embodiment, a shaft seal
device 100 is formed of a seal ring 10 mounted inside a seal casing
9 and the brush seal 21 mounted on the internal oil deflector
12.
[0067] In the thus configured shaft seal device 100 of the electric
rotating machine according to the first embodiment, a hydrogen gas
8 which is used as a cooling medium inside the machine attempts to
enter the seal cavity 13 from the gap between the internal oil
deflector 12 and a rotating shaft 7 due to the agitation effect of
the internal pressure and the rotating shaft 7 or the like.
However, since the brush seal 21 which basically does not have any
gap between itself and the rotating shaft 7 is mounted at the seal
cavity 13 side on the internal oil deflector 12, the hydrogen gas 8
does not enter the seal cavity 13.
[0068] Accordingly, a sealing oil 17 enters the seal cavity 13, but
the sealing oil 17 and the hydrogen gas 8 never come in contact
with each other, and thus the purity of the hydrogen gas 8 inside
the machine is never lowered due to mixing of gases (air) with the
sealing oil 17. As a result, it is unnecessary for the sealing oil
17 to undergo degassing, and it is unnecessary to provide a
degassing device 58 in a lubricating oil supply system shown in
FIG. 31. In this case, it is necessary to supply (fill with) a
sealing medium such as a sealing oil such that air is not mixed in
between the seal ring and the rotating shaft 7.
[0069] It is to be noted that the brush seal 21 naturally requires
no lubricating member according to the properties thereof. Also,
the brush 21 may be replaced by a seal ring having a white metal on
the inner circumferential surface thereof.
[0070] Next, a second embodiment of the shaft seal device of the
electric rotating machine of the invention will be described with
reference to FIG. 2. That is, a structure is provided in which a
brush seal 22 which is a sealing mechanism is mounted at the seal
cavity 13 side of the seal casing 9 which holds seal rings 10A and
10B which are the same as that of the prior art is mounted.
[0071] In a shaft seal device 101 of the second embodiment having
this configuration, the sealing oil is caused to flow from an axial
direction gap 18 of the seal ring 10A at the seal cavity side and
the seal ring 10B at the bearing side to narrow gaps 19 between the
seal ring 10A and rotating shaft 7, and between the seal ring 10B
and the rotating shaft 7, respectively, and then caused to flow out
to the seal cavity side and the bearing side, respectively.
However, because the brush seal 22 is provided at the seal cavity
13 side, the sealing oil 17 which flows out to the seal cavity 13
side never flows out to the seal cavity 13.
[0072] Thus, the hydrogen gas 8 which enters the seal cavity 13
from the gap between the internal oil deflector 12 and the rotating
shaft 7 does not come in contact with the sealing oil 17.
Consequently, even if the air from the outside mixes with the
sealing oils 17, the purity of the hydrogen gas 8 which is used as
cooling gas inside the machine is never lowered, and it is
unnecessary for degassing the sealing oil 17. Thus, it is
unnecessary to provide the degassing device 58 in the lubricating
oil supply system shown in FIG. 31 of the prior art.
[0073] Next, a third embodiment of the shaft seal device of the
electric rotating machine of the invention will be described with
reference to FIG. 3. In this embodiment, the internal oil deflector
12 of FIG. 28 is not provided, and a sealing mechanism which does
not require a lubricating member, e.g., a seal brush 24, is
supported by a brush seal holder 23 and is mounted to an end
bracket 3 at this portion. The brush seal 24 is provided with
multiple stages in the axial direction (3 stages in FIG. 3). A
shaft seal device 102 is configured by the brush seal 24 and the
seal ring 10 which is mounted on the seal casing 9.
[0074] In the third embodiment as configured above, the hydrogen
gas 8 which is use as the cooling gas inside the machine is
hindered from entering the seal cavity 13 by the brush seal 24. In
addition, the sealing oil 17 which flows out from the gap between
the seal ring 10 and the rotating shaft 7 is hindered from going
out from the seal cavity 13 to inside the machine by the brush 24
in the same manner. Accordingly, because the hydrogen gas 8 inside
the machine and the sealing oil 17 never come in contact with each
other, the air mixed with the sealing oil 17 is not discharged into
the hydrogen gas 8 inside the machine even if air mixes into the
sealing oil 17, and thus, the hydrogen gas purity is not lowered.
Therefore, it is unnecessary to provide a degassing device in the
supply system of the sealing oil 17 for degassing the sealing oil
17, and thus, it is unnecessary to provide the degassing device 58
of the supply system of the sealing oil 17 shown in FIG. 31 which
has been necessary in the shaft seal device of the prior art
electric rotating machine.
[0075] Next, a fourth embodiment of the electric rotating machine
including the shaft seal device of the invention will be described.
As shown in FIG. 4, in this embodiment, in the seal ring 10 formed
of a seal ring 10C at the seal cavity side and the seal ring 10B at
the bearing side, the axial direction length (width) of the seal
ring 10C is longer than the axial direction length (width) of the
seal ring 10B.
[0076] In the seal ring device 103 of the fourth embodiment formed
in this manner, the sealing oil 17 flows from the axial direction
gap 18 of the seal ring 10 into the narrow gaps 19 between seal
ring 10C and the rotating shaft 7, and between the seal ring 10B
and the rotating shaft 7, respectively, and flows out to the seal
cavity side and the bearing side, respectively.
[0077] At this time, because the seal ring 10C at the seal cavity
side has a longer axial direction length than the seal ring 10B at
the bearing side, the flow path resistance when the sealing oil 17
flows to the axial direction gap (narrow gap) 19 is larger than
that of the seal ring 10B at the bearing side. As a result, even
for the gap 19 in the same circumferential direction, the sealing
oil that flows to out to the seal cavity 13 side (shown by a dotted
arrow in the drawing) is less than the sealing oil 17 that flows
out to the bearing side.
[0078] By adjusting the axial direction length of the seal ring 10C
at the cavity side and the seal ring 10B at the bearing side in
this manner, the amount of the sealing oil 17 that flows out to the
seal cavity 13 side is extremely small, so that the amount of the
air mixed in the sealing oil 17 that is discharged to the hydrogen
gas 8 inside the seal cavity 13 is extremely small.
[0079] The fourth embodiment has the same configuration as that of
the prior art except the shape of the seal ring 10C at the seal
cavity side, and the seal cavity 13 is formed of the internal oil
deflector 12 that is further inside the machine. Because the amount
of the cooling hydrogen gas 8 circulating in inside the machine and
the hydrogen gas 8 circulating at the seal cavity 13 side is
lowered due to the presence of the internal oil deflector 12, the
extent to which the air mixed in the sealing oil 17 reduces the
purity of the hydrogen gas 8 inside the machine is extremely
low.
[0080] Accordingly, it is unnecessary to provide the degassing
device 58 in the supply system of the sealing oil 17 shown in FIG.
31 for degassing of the sealing oil 17. Thus, the degassing device
58 of the supply system of the sealing oil 17 which has been
necessary in the shaft seal device of the prior art electric
rotating machine is no longer necessary.
[0081] Next, a fifth embodiment of an electric rotating machine
including a shaft seal device 104 of the invention will be
described. As shown in FIG. 5, the seal ring at the seal cavity
side is replaced by a brush seal 25, and the brush seal 25 and the
seal ring 10B at the bearing side are held by the seal casing 9.
There is an axial direction gap 18 between the brush seal 25 and
the seal ring 10B, and the outer circumference thereof is pressed
by a spring 20. The inner circumference of the brush seal 25 is in
contact with the outer circumferential surface of the rotating
shaft 7, but there is a circumferential direction gap 19 between
the inner circumference of the seal ring and the outer
circumference of the rotating shaft 7.
[0082] In the embodiment configured in this manner, the sealing oil
17 flows from the axial direction gap 18 out only to the bearing
side via the circumferential direction gap 19 between the seal ring
10B at the bearing side and the rotating shaft 7. In addition, the
hydrogen gas 8 inside the machine which has entered the seal cavity
13 via the gap between the internal oil deflector 12 and the
rotating shaft 7 does not come in directly contact with the sealing
oil 17 because of the presence of the brush seal 25, and the air in
the sealing oil 17 is not discharged to the hydrogen gas 8, so that
the purity of the hydrogen gas 8 in the machine will not be
lowered. Accordingly, it is unnecessary to provide the degassing
device 58 in the sealing oil supply system 17 shown in FIGS. 30,
31, in order to perform degassing of the sealing oil 17, and thus
it is unnecessary for the degassing device 58 in the supply system
of the sealing oil 17, which has been necessary in the shaft seal
device of the prior art electric rotating machine. Furthermore,
because the hydrogen gas does not enter the seal cavity 13 because
of the brush seal 21A, the degassing device 58 is not required.
[0083] Next, a sixth embodiment of an electric rotating machine
including a shaft seal device 105 of the invention will be
described. As shown in FIG. 6, the internal oil deflector 12 and
the external oil deflector 11 are replaced by brush seals 21A and
21B, and these may be obtained in the same manner by attaching the
end bracket 3 and the bearing bracket 4. According to the
embodiment of FIG. 6, because the oil deflectors 11 and 12 are not
provided, component parts are less and this leads to reduced
cost.
[0084] FIG. 7 is a view showing a schematic configuration according
to a seventh embodiment of the invention. As shown in FIG. 7, the
brush seal mechanism comprises the brush holder 15 and a brush seal
mechanism main body.
[0085] The brush holder 15 encloses the inner part of the frame of
the dynamo-electric device and/or the outer part of the frame of
the dynamo-electric device and the outer circumferential side of
the rotating shaft 7, and a predetermined storage space is formed
therein. The brush seal mechanism main body is contained such that
a plurality of stages of brush seals 21 are formed along the axial
direction of the rotating shaft 7 which is inside the brush holder
15, and each of the brush seals 21 has a circular ring shaped brush
21b which contacts the rotating shaft 7, and has a base end support
portion 21a which supports the brush seal at the reverse rotating
shaft side. As shown in FIGS. 8A and 8B, each of the brush seals 21
is radially divided into a plurality of stages along the radial
direction, and the positions of the division 21ac of the base end
support portion 21a and the division 21bc of the brush 21b at the
adjacent stages are offset, so that the cooling gas in the frame
does not leak outside the frame. FIGS. 8A and 8B each show a
configuration of the two brushes 21 shown in FIG. 7 when viewed
from the axial direction, and they are formed as circles enclosing
the rotating shaft 7. In addition, as shown in FIGS. 8A and 8B, the
brush seal is divided in 2 (or into a number of 3 or more) in the
axial direction due to the assembly. In this case, because a gap is
formed in the division, there is the possibility that a large
volume oil leakage 14 in FIG. 7 occurs at this point.
[0086] Then, the brush seal 21 is disposed along the axial
direction of the rotating shaft in two stages or in a plurality of
stages, and the position of the division 21ac and 21bc of the brush
seal 21 is offset in the circumferential direction to be contained
in the brush holder, whereby the leakage 14 from the division can
be reduced.
[0087] It is to be noted that as shown in FIG. 7, the width of a
clamp portion that is provided at the base end support portion 21a
of the brush seal 21 is larger than the brush 21b, and thus a gap
is formed between the brush holder 15 and the brush seal 21 and
between the brushes 21b.
[0088] For this reason, dropping (bending) of the brush seal 21
occurs due to the pressure of the oil from the high pressure
portion toward the low pressure portion, a gap is formed between
the rotating shaft 7 and the front end of the brush 21b, and a
suitable pressuring (rotating shaft internal diameter--brush
internal diameter) can no longer be maintained.
[0089] FIG. 9 is a view for explaining the seventh embodiment of
the invention which has been conceived for solving these problems.
The inner circumferential portion of the brush holder 15 has a drop
prevention member 35 (step) which prevents the brush seal 21 from
dropping. In this manner, by nipping the brush 21 due to the action
of the drop prevention member 35, dropping of the brush seal 21 is
prevented, and pressure resistance and excellent sealing
capabilities are obtained.
[0090] FIG. 10 is a view for explaining an eighth embodiment of the
invention. The brush seal 21 has a moveable drop prevention member
26 for optionally changing the nipping width of the brush seal 21,
and the push-out amount of the drop prevention member 26 can be
adjusted by the adjusting screw 28. With this configuration, a
suitable nipping width can be provided.
[0091] The brush 21 which has several stages has gaps between the
brushes 21 as shown in FIG. 7. There is the possibility that a
liquid which leaks from the divisions 21ac and 21bc of the first
stage brush seal 21 passes through the gap, flows in the
circumferential direction of the rotating shaft, and leaks to the
next division.
[0092] In this manner, there is the possibility that the liquid may
reach the last stage and leak. This gap can be made smaller in the
embodiments shown in FIGS. 9 and 10, but it is expected quite a
large amount of gap will remain as shown in FIGS. 9 and 10.
[0093] FIG. 11 is a view for explaining a ninth embodiment of the
invention which has been conceived for solving this problem, in
which sealing plates 29 served as spacing members 29 are provided
which alternate between a plurality of brush seals 21. As a result,
there is little or no gaps between the brushes 21, the paths for
leakage of a fluid is covered, and the amount of leakage is
reduced.
[0094] FIG. 12 is a view for explaining a tenth embodiment of the
invention, in which the spacing member 29 shown in FIG. 11 is
replaced by a small brush 30 which contacts the rotating shaft 7,
thereby achieving the same effect as that in FIG. 11.
[0095] Hereinafter, an eleventh embodiment will be explained.
[0096] The brush seal 21 and the rotating shaft 7 need to be
maintained in a concentric state during operation, but the
concentric state may be different from that at the time of assembly
due to lifting up of the rotating shaft 7 or by thermal deformation
of the holder 15.
[0097] FIG. 13 is a view for explaining an eleventh embodiment of
the invention which is a measure for dealing with this problem. A
holder support casing 51 is provided, the seal mechanism is
contained inside the casing 51, and a plurality of locations on the
cylinder are supported by a spring 42 so as to be movable in the
radial direction. Consequently, the sealing mechanism is returned
to the concentric position due to the reactive force of the brush
seal 21 in the bias direction of the rotating shaft 7.
[0098] FIG. 14 is a view for explaining a twelfth embodiment of the
invention, in which the functions of FIG. 13 are realized by
another structure. That is, a support plate 34 is mounted on the
outer circumferential surface of the brush seal 21 and is supported
by a spring 33 between the spring plate 34 and the brush holder 15.
It is to be noted that packing 53 is provided the slide surface
between the brush holder 15 and the support plate 34, thereby
preventing leakage from the slide surface.
[0099] FIG. 15 is a view for explaining a thirteenth embodiment of
the invention. The spring 33 in FIG. 14 is replaced by bellows 50,
and a gap sensor 38 for detecting relative positions of a pipe 36
for feeding and discharging a high pressure fluid 37 in the bellows
50, the rotating shaft 7 and the brush 21, so that the concentric
state can be controlled externally.
[0100] The bias state of the rotating shaft 7 and the brush holder
15 can be measured by the gap sensor 38 mounted on the brush holder
15. The pressure fluid is supplied or discharged so as to lower the
pressure in the bellows 50 which have been biased so as to cancel
the bias amount or so as to increase the pressure inside the
bellows 50 at the opposite side, and the length of the bellows 50
is thereby adjusted.
[0101] By disposing four gap sensors 38 and bellows 50 at least on
the circumference at a pitch of 90.degree., bias in any direction
can be handled.
[0102] FIG. 16 is a view for explaining a fourteenth embodiment of
the invention. The bellows 50 in FIG. 15 are replaced by a
piezoelectric element 39, the length thereof is controlled by
changing the voltage applied to the piezoelectric element 39, and
the same functions as those of FIG. 15 are thereby achieved.
[0103] FIGS. 17 and 18 each show a fifteenth embodiment of the
invention in which a brush type contact seal device is applied to a
turbine generator. The contact seal device is provided as contact
seals 40 and 41 outside the machine and inside the machine of a
seal mounting seat 44 which is mounted on the inner circumference
of the bearing bracket 4. The contact seal device supplies the
sealing oil 17 between the contact seals 40 and 41 to seal the
hydrogen gas 8 inside the machine.
[0104] The application of the fifteenth embodiment, that is, the
contact type seal ring device makes it possible to decrease
increase in an excessive sealing oil amount generated in the
floating seal of the prior art system or rubbing vibration caused
by frictional force.
[0105] FIG. 19 is a view for explaining a sixteenth embodiment of
the invention. In addition to the seal mounting seat 44 provided at
the inner circumference edge of the end bracket 3 shown in FIG. 17,
brush type contact seals 40A and 41A are provided at both inside
the machine and outside the machine as shown in FIG. 15. Examples
of other possible configurations naturally include gap sensors 38
and 38B, bellows 50A and 50B, and packings 27A and 27B. In this
case also, the same effects as those in FIG. 15 are obtained.
[0106] FIG. 20 is an axial direction cross-sectional view of a seal
ring device area of a dynamo-electric device for explaining a
seventeenth embodiment of the invention. The embodiment differs
from the prior art shown in FIG. 28 in that a seal mechanism 31
comprising a brush seal is mounted at the side surface opposing the
bearing 6 of the seal casing 9 which is mounted on the end bracket
3 of the prior art, so that the brush seal contacts the outer
circumferential surface of the rotating shaft. Aside from this, the
structural elements are the same as those of FIG. 28, and the basic
effects of the shaft seal device (which comprises the seal casing 9
and seal ring 10) are exactly the same.
[0107] In the embodiment of FIG. 20 thus configured, the sealing
oil 17 supplied to the gap between the seal ring 9 and the rotating
shaft 7 configuring the prior art shaft seal device and the
lubricating oil supplied to the bearing device (the device
comprising the bearing bracket 4, bearing stand 5, and bearing 6)
is prevented from being mixed by means of the brush seal 31 which
is mounted at the bearing device side of the seal casing 9 of the
prior art shaft seal device. Because each of the oils is circulated
by a different circulation system, there is no mixing of the oils.
Accordingly, the air mixed into the lubricating oil never passes
the brush seal 31 and gets discharged inside the prior art shaft
seal device. In addition, the hydrogen gas 8 inside the machine
which is mixed in the sealing oil 17 never passes the brush seal 31
and gets discharged at the bearing device side. Therefore, the
purity of the hydrogen gas 8 in the machine is not lowered due to
the air mixed in the sealing oil 17, so that it is unnecessary for
degassing of the sealing oil 17 and thus it is unnecessary to
provide the degassing device 58 in the lubricant supply system, as
is the case of the prior art. The brush seal 31 naturally requires
no lubricant according to the properties thereof.
[0108] FIG. 21 is a view for explaining a modification of FIG. 20,
in which the brush seal 31 shown in FIG. 20 is not mounted at the
side surface of the seal casing 9 of the shaft seal device but at
the opposite surface to the seal casing 9 which is the side surface
of the bearing 6. The same effects can be obtained as in the case
of FIGS. 21 and 22.
[0109] Next, an eighteenth embodiment of the electric rotating
machine including the shaft seal device of the invention will be
described with reference to FIGS. 22, 23, 24, and 25. FIG. 22 is an
axial direction cross-sectional view of an area around the shaft
seal device of the electric rotating machine according to the
eighteenth embodiment of the invention. The embodiment differs from
the prior art shown in FIG. 2 in that mounting is at the side
surface opposite to the external oil deflector 11 which is the side
surface of the bearing 6. Aside from this, the structural
components are the same as those of FIG. 28, and the basic effects
as the shaft seal device 107 are exactly the same as those of the
prior art.
[0110] In the thus configured eighteenth embodiment, by providing
the brush seal 31 at the side surface of the shaft end side of the
bearing 6 of the bearing device, the sealing oil 17 supplied to the
prior art bearing device and the lubricating oil supplied to the
bearing device never come in contact with the outside air. Air does
not mix with these oils, and only mixes with the cooling hydrogen
gas 8 which contacts inside the machine, and thus, air is never
discharged from these oils to the hydrogen gas 8 inside the
machine. Accordingly, the purity of the hydrogen gas 8 inside the
machine is never lowered and degassing of the sealing oil 17 is not
required, so that it is unnecessary for the lubricant supply system
shown in FIG. 30 to have the degassing device 58.
[0111] FIG. 23 shows an example in which the brush seal 31 is
provided at the side surface of the external oil deflector 11
inside the machine rather than at the side surface of the shaft end
side of the bearing 6. As shown in FIG. 23, by providing the brush
seal 31 at the side surface of the external oil deflector 11
outside the machine, the lubricating oil also lubricates the side
surface of the shaft end side of the bearing 6, and the cooling
capability of the bearing device is not reduced.
[0112] FIG. 24 shows an example in which the brush seal 31 provided
at the shaft end side of the external oil deflector 11 rather than
at the side surface of the shaft end side of the bearing 6. In the
case where the brush seal 31 is provided at the shaft end side of
the external oil deflector 11 as shown in FIG. 24, the mounting of
the brush seal 31 is easy and it may also be used for a device
which has already been designed.
[0113] FIG. 25 shows an example in which a brush seal holder 23 is
mounted on the axial end side which is the side surface of the
bearing bracket 4 instead of the external oil deflector 11, and the
brush seal 31 is provided at the brush holder 23. In the
configuration in which the brush seal 31 is mounted in place of the
external oil deflector 11 as shown in FIG. 25, there are less
component parts and thus reduced cost.
[0114] Next a nineteenth embodiment of an electric rotating machine
of the invention will be described with reference to FIGS. 26 and
27. FIGS. 26 and 27 are axial direction cross-sectional views of an
area around the shaft seal device of the electric rotating
machine.
[0115] The embodiment differs from the prior art shown in FIG. 28
in that the brush seal 31 is mounted on the side surface of the
bearing 6 inside the machine in FIG. 26, the external oil deflector
11 is not provided on the bearing bracket 4, and instead, the brush
seal holder 23 with a built-in brush seal 31 is mounted to the
bearing bracket 4, and the seal ring 9 which is the prior art shaft
seal device is not mounted in FIG. 27. The other structural
elements are the same as FIG. 28.
[0116] In the nineteenth embodiment configured in this manner,
since the hydrogen gas 8 inside the machine is sealed newly with
the brush seal 31 provided on the side surface of the bearing 6
inside the machine not to leak outside of the machine in the
configuration of FIG. 26, the hydrogen gas 8 is not leaked outside
the machine and does not come in contact with the lubricant
supplied to the bearing 6. In the configuration of FIG. 27, the
lubricating oil which lubricates the bearing 6 and the hydrogen gas
8 inside the machine are sealed by a brush seal 31 which is newly
provided with a shaft end portion such that leakage to the outside
the machine does not occur, the brush seal 31 having basically zero
of the gap in the radial direction with respect to the rotating
shaft 7. Therefore, there is no contact of the lubricating oil with
the outside air nor leakage of the hydrogen gas to the outside.
Accordingly, even in the case where the lubricating oil is supplied
to the bearing 6 again via the circulating device and flows out to
the inside of the machine, air is never discharged from the
lubrication oil to the hydrogen gas 8 inside the machine and thus,
the purity of the hydrogen gas 8 inside the machine is not lowered.
Consequently, since it is unnecessary to provide the degassing
device 58 in the lubricant supply system shown in FIG. 29 to
perform degassing of the lubricant, the degassing device 58 of the
oil supply system which has been necessary in the shaft seal device
of the prior art electric rotating machine is no longer
necessary.
[0117] This invention is not limited to the above-described
embodiments and may be effected with various modifications. For
example, the above-described brush seals 21, 21A, 21B and 31 may be
formed of a flame resisting material. By being formed of a flame
resisting material, even in the unlikely event that the hydrogen
gas 8 leaks and is ignited, the seal portion is not damaged by
flame causing an increase in the leak amount of the hydrogen gas 8.
It is thus possible for the amount of leakage to be minimized, and
thus safety is improved for the electric rotating machine which
uses the hydrogen gas 8 as the cooling gas.
[0118] This invention may be applied to any of a dynamo-electric
device which continuously scavenges a cooling medium, an electric
generator having a lubricating system which separately circulates a
bearing lubricant and a sealing medium, respectively, and an
electric rotating machine for cooling an electric rotating machine
by use of a completely sealed cooling medium.
* * * * *