JP2013155784A - Shaft seal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure accuracy in attaching a brush seal ring to a rotating shaft, even if machining precision of a channel part of a channel-type brush seal is not high, thereby significantly improving effect of reducing hydraulic fluid to be leaked.SOLUTION: A shaft seal device includes: an involute channel-type brush seal ring 26 with a channel part 30 formed on an outer circumferential surface; a high-pressure-side brush holder 27; and a low-pressure-side brush holder 28. On an abutment surface between the high-pressure-side brush holder 27 and the low-pressure-side brush holder 28, a groove with a space for housing the channel part 30 is formed. A ring-shaped brush holder holds the channel-type brush seal ring 26 between the high-pressure-side brush holder 27 and the low-pressure-side brush holder 28. The high-pressure-side brush holder 27 and/or the low-pressure-side brush holder 28 have a fitting structure with a pressure bulkhead or a pressure container in an installation position, and have a position reference surface for determining the installation position of the channel-type brush seal ring.

Description

  Embodiments described herein relate generally to a shaft seal device.

  Among rotating machines such as a steam turbine, a gas turbine, an air compressor, and a pump, there are rotating machines in which a rotating shaft extends across a region where a differential pressure of a working fluid is generated. In this type of rotating machine, a shaft seal device is indispensable in order to prevent the working fluid from leaking into the low pressure region along the rotating shaft.

  As this type of shaft seal device, a brush seal using a brush composed of a large number of thin wires is known. A brush seal is fixed in combination with a labyrinth seal or the like on the inner peripheral surface of the hole through which the rotary shaft passes through the pressure partition wall that partitions the high pressure region and the low pressure region.

Conventionally, there are two types of brush seals of this type: a welding type brush seal and a channel type brush seal.
Among them, the welding type brush seal is a brush in which a thin wire bundle arranged in a certain thickness is sandwiched between a ring-shaped front plate and back plate processed by machining, and the outer peripheral side of the front plate and back plate is fixed by welding. It is a seal. As a prior art regarding this welding type brush seal, the welding type brush seal described in patent document 1 can be mentioned, for example.

  On the other hand, the channel-type brush seal is formed by inserting a metal core into a thin wire and bending it, forming a channel portion by bending a thin plate from the outside at the bent portion, and bending the whole into a ring shape. As a prior art regarding this channel type brush seal, for example, there is a channel type brush seal described in Patent Document 2.

US4204629 JP 2004-044883 A

  The effect of reducing the leakage of the working fluid by the brush seal depends largely on the state of management of the gap formed between the outer peripheral surface of the rotating shaft and the brush tip. In order to enhance the leakage reduction effect, the brush seal ring is accurately positioned so that the relative position between the rotating shaft and the brush ceiling is a predetermined position, and the gap between the outer peripheral surface of the rotating shaft and the brush tip is determined. It is necessary to manage the gap.

  In this regard, in the welding type brush seal, the front plate and the back plate are also precisely machined, so that the dimensional accuracy of the completed brush seal ring can be equivalent to the assembly dimensional accuracy of the rotating machine. . Therefore, by directly fitting the brush seal ring body into a ring-shaped groove that opens to the inner peripheral side of the pressure bulkhead or the inner peripheral side of the labyrinth seal ring, the brush seal ring is positioned accurately, and the outer peripheral surface of the rotary shaft It is easy to accurately manage the gap between the brush tip.

  However, the production of welded brush seals requires special jigs and winding machines for the precise winding of very thin wires with a diameter of 0.1 mm or less around the front and back plates. Work and heat treatment work after welding are necessary, and the manufacturing cost is high.

  On the other hand, although the channel type brush seal has the advantage that the manufacturing cost can be greatly reduced by crimping the channel part into a ring shape, from the aspect of accuracy, the channel part is crimped and bent. Therefore, it is not possible to expect a processing finish accuracy equivalent to the assembly accuracy of the rotating machine to be mounted.

  For this reason, in order to obtain a channel-type brush seal with high finishing accuracy, it is necessary to increase the accuracy of the pre-processing of the material or to increase the processing accuracy in the caulking processing device, which significantly increases the production cost. There is a problem.

  Therefore, the object of the present invention is to solve the problems of the prior art and to ensure the accuracy of mounting the brush seal ring on the rotating shaft even if the processing accuracy of the channel portion of the channel type brush seal is not high. Another object of the present invention is to provide a shaft seal device that can greatly improve the effect of reducing leakage of working fluid.

  In order to achieve the above object, the present invention provides a shaft seal device for sealing between a high pressure region and a low pressure region adjacent to each other in the axial direction of a rotating shaft of a rotary machine, and a metal core in the longitudinal center of a strip-shaped thin wire bundle. A channel brush is formed by sandwiching the thin wire bundle between the core portion and the channel portion that is folded in the longitudinal direction by covering a strip-like thin plate from the outside of the bent portion of the thin wire bundle. An internally wound channel type brush seal ring in which the channel brush is formed in an annular shape so as to be on the outer peripheral side, a high pressure side brush holder facing the high pressure side region, a low pressure side brush holder facing the low pressure side region, And a groove that forms a space for accommodating the channel portion of the channel-type brush seal ring is formed on the abutment surface of the high-pressure side brush holder and the low-pressure side brush holder. An annular brush holder that sandwiches and fixes the channel-type brush seal ring between the high-pressure side brush holder and the low-pressure side brush holder, and the high-pressure side brush holder and / or the low-pressure side brush holder are installed It has a position reference surface that forms a fitting structure with a pressure bulkhead or a pressure vessel at a position and determines an installation position of the channel type brush seal ring.

  Further, the present invention provides a shaft sealing device that seals between a high pressure region and a low pressure region adjacent to each other in the axial direction of a rotating shaft of a rotary machine, and a plurality of sheets each having a predetermined gap between the rotating shaft surface. A labyrinth seal ring that is installed on a partition wall that has an annular fin and divides the high-pressure region and the low-pressure region, and is bent by applying a cored bar to the center in the longitudinal direction of the strip-shaped thin wire bundle. A channel brush is formed by sandwiching the thin wire bundle between a channel portion bent in a longitudinal direction and covered with a thin plate, and the channel brush is formed in an annular shape so that the channel portion is on the outer peripheral side. A high-pressure side brush holder comprising: a wound channel type brush seal ring; a high-pressure side brush holder facing the high-pressure side region; and a low-pressure side brush holder facing the low-pressure side region. A groove that forms a space in which the channel portion of the channel-type brush seal ring is accommodated is formed on the abutting surface of the brush and the low-pressure side brush holder. An annular brush holder that holds the channel-type brush seal ring concentrically and in parallel with the labyrinth seal ring, and the high-pressure side brush holder and / or the low-pressure side brush holder includes the labyrinth seal It has a position reference surface which forms a fitting structure with the ring and determines the installation position of the channel type brush seal ring.

It is a longitudinal section showing an axial flow turbine which is a rotary machine to which a shaft seal device by the present invention is applied. It is a longitudinal section showing a shaft seal device by a 1st embodiment of the present invention. It is a perspective view which shows a part of channel type brush seal ring which comprises the shaft seal apparatus by 1st Embodiment of this invention. It is explanatory drawing of the manufacturing method of the channel type brush seal ring of FIG. It is a longitudinal cross-sectional view which shows the shaft sealing apparatus by 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the shaft seal apparatus by 3rd Embodiment of this invention. It is a longitudinal section showing a shaft seal device by a 4th embodiment of the present invention. It is a longitudinal cross-sectional view which shows the modification of the shaft seal apparatus of FIG. It is a side view which shows the shaft seal apparatus by 5th Embodiment of this invention. It is a longitudinal section showing a shaft seal device by a 6th embodiment of the present invention. It is a longitudinal section showing a shaft seal device by a 7th embodiment of the present invention.

Embodiments of a shaft seal device according to the present invention will be described below with reference to the accompanying drawings.
First embodiment
FIG. 1 is a cross-sectional view showing an axial turbine that is an example of a rotating machine to which a shaft sealing device according to the present invention is applied. In FIG. 1, reference numeral 10 indicates the entire axial turbine. Reference numeral 12 indicates that the axial turbine 10 is a rotating shaft. In this axial flow turbine 10, the rotating shaft 12 is rotated by a working fluid F such as steam to obtain kinetic energy from the output shaft end 13, or conversely, the rotating shaft 12 is rotated to rotate the working fluid F. It is a rotating machine that transmits energy to the machine.

  The inside of the pressure vessel 14 is partitioned by a pressure partition 16 into two pressure chambers, a high pressure chamber 15 as a high pressure region and a low pressure chamber 17 as a low pressure region. The rotary shaft 12 passes through the pressure vessel 14 and the pressure partition wall 16 and is horizontally supported rotatably by bearings 18 and 19 installed outside the pressure vessel 14.

  The pressure vessel 14 is formed with a fluid inlet 20 that introduces the working fluid F into the high-pressure chamber 15 and a fluid outlet 21 that leads the working fluid F from the low-pressure chamber 17. A plurality of nozzle portions 22 from which the working fluid F in the high pressure chamber 15 is ejected are formed in the pressure partition 16. In the rotary shaft 12, a plurality of blades 24 are attached to the outer periphery of the disk 23, and the rotary shaft 12 rotates by jetting high-pressure working fluid F from the nozzle portion 22 toward the blades 24. ing.

  In such an axial flow turbine 10, the shaft seal device 25 is provided between the high pressure region and the low pressure region adjacent to each other in the axial direction of the rotating shaft 12, and the working fluid F leaks along the rotating shaft 12. Is preventing. In this embodiment, the shaft seal device 25 is provided for the seal of the pressure partition 16 that partitions the high pressure chamber 15 and the low pressure chamber 17, the seal between the high pressure chamber 15 and the outside air, and the seal between the low pressure chamber 17 and the outside air. Located in three places.

  Next, FIG. 2 shows a cross section of the shaft seal device 25 installed in the pressure partition 16. The shaft seal device 25 includes a channel-type brush seal ring 26 and a high-pressure side brush holder 27 and a low-pressure side brush holder 28 that are brush holders for holding the channel-type brush seal ring 26.

  FIG. 3 is a view showing a part of the channel type brush seal ring 26. The channel-type brush seal ring 26 is a ring-shaped brush seal in which a brush made of innumerable fine wires made of steel is fixed by a channel portion 30 obtained by bending a thin strip.

  Here, FIG. 4 is a diagram showing a method for manufacturing the channel-type brush seal ring 26. The thin wires used as the material are cut into a certain length, and are bundled to form a long strip-like thin wire bundle 31. Then, a cored bar 32 is attached along the center line in the length direction of the strip-shaped thin wire bundle 31. Further, a strip-shaped thin plate 33 is applied to the lower surface of the bent portion of the thin wire bundle 31. And the both ends of the strip | belt-shaped thin board 33 with the thin wire bundle 31 are bend | folded by the roll caulking process etc. to a length direction, and it shape | molds in a linear channel brush. The bent thin plate 33 constitutes a channel portion 30 that holds the thin wire bundle 31 in a folded state with the cored bar 32 inside.

  Next, the inner winding brush shown in FIG. 3, that is, the channel-type brush seal ring 26 is formed by bending the channel portion 30 into an annular shape so that the tip of the thin wire bundle 31 is inside. In the case of the channel-type brush seal ring 26, the thin plate 33 is crimped or the channel portion 30 is bent into an annular shape, so that the dimensional accuracy in the finished product is relatively low, but can be manufactured at a relatively low cost. The point is a great advantage.

  The channel type brush seal ring 26 molded in this way is sandwiched between a high pressure side brush holder 27 and a low pressure side brush holder 28 as shown in FIG. A groove 34 that is continuous in the circumferential direction is formed on the abutting surface of the high-pressure side brush holder 27, and a groove 35 is also formed on the inner side surface of the low-pressure side brush holder 28. A space in which the channel portion 30 of the channel-type brush seal ring 26 is fitted is formed. At the leading ends of the high-pressure side brush holder 27 and the low-pressure side brush holder 28, the thin wire bundle 31 is sandwiched so as to protrude. The abutting surfaces of the high-pressure side brush holder 27 and the low-pressure side brush holder 28 are fitted to each other without a gap. In this embodiment, the high-pressure side brush holder 27 and the low-pressure side brush holder 28 are welded. Are joined together. The high-pressure side brush holder 27 and the low-pressure side brush holder 28 are adapted to fit with the pressure partition wall 16 and the pressure vessel 14 at the installation position.

  In the first embodiment, the high-pressure side brush holder 27 and the low-pressure side brush holder 28 of the shaft seal device 25 have the following position reference surfaces for accurately attaching the channel-type brush seal ring 26 to the planned installation position. Is formed.

  A radial position reference surface 36 of the rotary shaft 12 is formed on the outer peripheral surface of the high pressure brush holder 27, and an axial position reference surface 37 is formed on the outer surface of the high pressure brush holder 27. . These position reference surfaces 36 and 37 are precisely machined by a machine tool such as a lathe, and the dimensional accuracy necessary for accurate positioning is secured in advance. Similarly, a radial position reference surface 38 is formed on the outer peripheral surface of the low pressure side brush holder 28, and an axial position reference surface 39 is formed on the outer surface of the low pressure side brush holder 28.

  In this embodiment, the high-pressure side brush holder 27 and the low-pressure side brush holder 28 have the radial position reference surface set to the outer peripheral surface, but the inner peripheral surface can also be used as the radial position reference surface. It is.

The shaft seal device according to the present embodiment is configured as described above. Next, the operation and effect thereof will be described.
As described above, the channel-type brush seal ring 26 incorporated in the shaft seal device 25 is manufactured through caulking or bending, so that the finished shape of the channel portion 30 is expected to have high dimensional accuracy. Can not. If the channel-type brush seal ring 26 is inserted into an installation groove formed in the pressure partition wall 16 to be installed, the finishing accuracy of the channel portion 30 is low, so that the channel-type brush seal ring 26 is placed at the predetermined installation positions in the radial direction and the axial direction. Accurate installation is difficult.

  Therefore, when the channel type brush seal ring 26 is accurately attached to the installation position of the pressure bulkhead 16, the following is performed.

As shown in FIG. 2, the high-pressure side brush holder 27 and the low-pressure side brush holder 28 that sandwich the channel portion 30 are fixed to a predetermined installation position on the side surface of the pressure partition 16 using an assembly bolt (not shown). A notch groove 40 is formed in an annular shape concentric with the rotary shaft 12 along the opening edge of the hole through which the rotary shaft 12 passes, on the side surface on the high pressure side of the pressure partition wall 16. The brush holder 28 is fitted into the notch groove 40. The groove outer peripheral surface and the groove side surface forming the notch groove 40 are precisely machined by a machine tool.
In this embodiment, the high-pressure side brush holder 27 has a radial position reference surface 36 that is curved in advance with high accuracy in accordance with the shape of the groove outer peripheral surface of the notch groove 40 by a machine tool such as a lathe. The side brush holder 28 is also precisely axially machined in advance so as to form a radial position reference surface 38 that is preliminarily matched to the shape of the notch groove 40 and a plane perpendicular to the rotation axis. A position reference surface 39 is provided. In the fitting structure in which the integrated structure in which the channel-type brush seal ring 26 is sandwiched between the high-pressure side brush holder 27 and the low-pressure side brush holder 28 is fitted into the notch groove 40, the channel-type brush is based on the position reference surfaces 36 and 38. The radial position of the seal ring 26 is determined. The position in the axial direction is determined by the position reference plane 39. Therefore, although it is the channel type brush seal ring 26 with a low dimensional accuracy, it becomes possible to fix to a predetermined position with a sufficient precision. In addition, the channel type brush seal ring 26 can be manufactured at a relatively low cost as compared with the welding type brush seal, so that the manufacturing cost can be greatly reduced.

  Furthermore, in the case of the channel-type brush seal ring 26, it is extremely important to set a slight gap G between the tip of the thin wire bundle 31 and the outer peripheral surface of the rotary shaft 12. Therefore, after the high-pressure side brush holder 27 and the low-pressure side brush holder 28 are integrally fitted and attached to the notch groove 40 for installing the pressure bulkhead 16, the channel is referenced with respect to the radial position reference surfaces 36 and 38. By processing the inner diameter portion of the mold brush seal ring 26 and precisely finishing the inner diameter, the gap G with the rotary shaft 12 can be set accurately. The gap G can be set precisely within a range of 0.0 mm.

  As described above, the channel-type brush seal ring 26 is fixed to the pressure bulkhead 16 by using the high-pressure side brush holder 27 and the low-pressure side brush holder 28 having the position reference surface, so that the position is accurately fixed and rotated. It is possible to set the gap G with the shaft 12 with high accuracy. The sealing effect of the channel-type brush seal ring 26 is significantly reduced when the gap G between the inner diameter portion of the thin wire bundle 31 and the outer peripheral surface of the rotary shaft 12 is large or uneven. Since the seal ring 26 can be accurately attached and the gap G can be set very small and accurately, the sealing effect can be enhanced, the leakage of the working fluid F can be significantly reduced, and the thermal efficiency of the steam turbine can be improved.

  Further, in the case of a rotating machine such as the axial flow turbine 10, if the working fluid F is steam, the rotating shaft 12 may expand due to the heat of the steam and the rotating shaft 12 may be shaken. If the channel-type brush seal ring 26 is installed on the pressure partition wall 16, the thin wire bundle 31 forming the brush seal bends following the shake of the rotating shaft 12, so that the channel-type brush seal ring 26 increases the pressure. Leakage of the working fluid F in the chamber 14 into the low pressure chamber 15 can be reduced.

  As described above, in the present embodiment, the example in which the shaft seal device 25 is installed in the pressure partition wall 16 has been described, but the pressure vessel 14 is also installed in exactly the same manner.

Second embodiment
Next, a second embodiment of the shaft seal device of the present invention will be described with reference to FIG. In addition, the same reference number is attached | subjected to the component same as the shaft seal apparatus shown in FIG. 2 of 1st Embodiment, and the detailed description is abbreviate | omitted.

  In the first embodiment described above, the high pressure side brush holder 27 holding the channel type brush seal ring 26 and having the position reference surface and the low pressure side brush holder 28 are joined by welding, whereas this second embodiment. In the embodiment, the high-pressure side brush holder 27 and the low-pressure side brush holder 28 are fastened with bolts and joined into an integral structure.

  In FIG. 5, reference numeral 42 indicates a fastening bolt. In this embodiment, the low-pressure side brush holder 28 is formed with female screw holes 43 in the thickness direction, and a plurality of the female screw holes 43 are arranged in the circumferential direction at a predetermined interval. The high-pressure brush holder 27 is similarly formed with a screw hole 44 in the thickness direction. After the channel portion 30 of the channel-type brush seal ring 26 is accommodated in the grooves 34 and 35 and the high-pressure side brush holder 27 and the low-pressure side brush holder 28 are fitted together, the tightening bolt 42 is tightened into the female screw hole 43. Accordingly, the channel side brush seal ring 26 can be fixed by being sandwiched between the high pressure side brush holder 27 and the low pressure side brush holder 28.

  According to the second embodiment of the present invention configured as described above, similarly to the first embodiment, the position reference surfaces 36, 38, With reference to 39, it is possible to fix it at a predetermined position with high accuracy. Further, the gap G with the rotary shaft 12 can be accurately set by processing the inner diameter portion of the thin wire bundle 31 with the radial position reference surfaces 36 and 38 as a reference and precisely finishing the inner diameter of the inner diameter portion. Can do. The gap G can be precisely set within a range of 0.0 mm, and the gap G can be set very small and accurately as in the first embodiment, so that the sealing effect is enhanced and the working fluid F leaks. Can be significantly reduced, and the thermal efficiency of the steam turbine can be improved.

  Furthermore, according to the second embodiment of the present invention, since the high-pressure side brush holder 27 and the low-pressure side brush holder 28 are fastened not by welding but by the fastening bolts 42, the following effects can be obtained.

  That is, in the channel type brush seal ring 26, the tip of the thin wire bundle 31 forming the brush seal comes into contact with the rotating shaft 12 that rotates at high speed, and wear progresses, so that the gap G gradually increases or the fine wire falls off. As the aging progresses. In addition, due to improper operation of the axial flow turbine 10, the fine wire bundle 31 may be damaged by water hammer or scale collision. In this case, by loosening and removing the tightening bolts 42, it becomes possible to remove only the deteriorated or damaged channel-type brush seal ring 26, replace it with a new one, and easily restore it.

Third embodiment
Next, FIG. 6 is a diagram showing a shaft seal device according to a third embodiment of the present invention. In addition, the same referential mark is attached | subjected to the component same as FIG. 5 of 2nd Embodiment, and the detailed description is abbreviate | omitted.

  A groove 34 that is continuous in the circumferential direction is formed on the abutting surface of the high-pressure side brush holder 27, and a groove 35 is also formed on the inner surface of the low-pressure side brush holder 28, and the channel-type brush is formed by these grooves 34 and 35. A space for accommodating the channel portion 30 of the seal ring 26 is formed. The high pressure side brush holder 27 is provided with a position reference surface 36, and the low pressure side brush holder 28 is provided with position reference surfaces 38 and 39 in the same manner as in the first and second embodiments.

  Since the channel portion 30 of the channel-type brush seal ring 26 has undergone caulking or bending, the dimensional accuracy of the outer diameter is not so high, and a gap may be formed between the inner surfaces of the grooves 34 and 35. Through this gap, the working fluid F in the high pressure chamber 15 may blow through the low pressure chamber 17 and increase the amount of leakage.

  Therefore, in the third embodiment, a heat-resistant filler 45 such as carbon graphite is used, and the filler 45 is packed between the channel portion 30 of the channel-type brush seal ring 26 and the inner surfaces of the grooves 34 and 35. There are no gaps.

  According to the third embodiment of the present invention configured as described above, there is no gap between the inner surfaces of the grooves 34 and 35 even if the channel portion 30 is not very high in dimensional accuracy. Therefore, it is possible to prevent the working fluid F from being blown through and to cause the channel-type brush seal ring 26 to exhibit a desired sealing effect.

Fourth embodiment
Next, a shaft seal device according to a fourth embodiment of the present invention will be described with reference to FIGS. In addition, the same referential mark is attached | subjected to the same component of FIG. 5 of 2nd Embodiment, and the detailed description is abbreviate | omitted.
In the fourth embodiment, as shown in FIG. 7, an annular fin 46 protruding in the radial direction is formed on the inner peripheral surface of the low-pressure side brush holder 28. In this case, the gap G ′ between the outer peripheral surface of the rotating shaft 12 and the tip of the fin 46 is set larger than the gap G between the thin wire bundle 31. FIG. 8 is an example in which two fins 46 are provided.

  As already described, in the channel-type brush seal ring 26, the tips of the thin wires of the thin wire bundle 31 come into contact with the rotating shaft 16 that rotates at high speed, and wear progresses or breaks, so that the gap G gradually increases. May grow. As the interval G increases, the amount of leakage of the working fluid F in the high pressure chamber 14 toward the low pressure chamber 15 increases.

  On the other hand, according to the fourth embodiment of the present invention, even if the thin wire bundle 31 is worn or damaged, the leakage amount of the working fluid F is rapidly increased by providing the fins 46. Can be suppressed.

  When the thin wire bundle 31 is worn or damaged, the axial flow turbine 10 is brought to an emergency stop. However, even during the stop operation during this time, the fin 46 can prevent the working fluid F from leaking out of the machine. .

  7 shows an example in which the fins 46 are provided on the inner peripheral surface of the low-pressure side brush holder 28. However, fins are provided on the inner peripheral surface of the high-pressure side brush holder 27, or fins are provided on both of them. You may do it. Further, the number of fins is not particularly limited.

Fifth embodiment
Next, a shaft seal device according to a fifth embodiment of the present invention will be described with reference to FIG.

  In the fifth embodiment, the channel-type brush seal ring 26 is equally divided in the circumferential direction and divided into a plurality of, for example, four brush seal ring divided bodies 26a to 26d, and the same number of brush holder divided bodies for the brush holders. This is an embodiment divided equally into 50a to 50d. The brush holder divided bodies 50a to 50d are the same as in the first embodiment in that the brush holder divided bodies 50a to 50d are composed of a high pressure side brush holder 27 and a low pressure side brush holder 28 as shown in FIG. The individual brush seal divided bodies 26a to 26d and the brush holder divided bodies 50a to 50d are assembled in advance before being installed in the pressure partition 16, and a set of four brush seal divided assemblies is prepared.

  Among large rotating machines, there is a rotating machine such as a steam turbine composed of a pressure vessel or a pressure partition divided into two along a horizontal plane. When the shaft seal device 25 of the present embodiment is installed in the pressure partitions 16a and 16b divided into two, the following may be performed.

  In this type of rotary machine, the lower half pressure partition 16a is set first. The lower half pressure bulkhead 16a is fixed with a lower half brush seal assembly, that is, a brush seal assembly comprising brush seal ring divided bodies 26c and 26d and brush holder divided bodies 50c and 50d using an assembly screw 47. The Next, the rotary shaft 12 is set. After this, the upper half pressure seal assembly, that is, the brush seal assembly comprising the brush seal ring segments 26a and 26b and the brush holder segments 50a and 50b is fixed using the assembly screw 47. A partition wall 16b is set.

  According to the shaft seal device 25 of the fifth embodiment as described above, the brush seal divided assembly divided in the circumferential direction, the assembly of the brush seal ring divided body 26a and the brush holder divided body 50a, and the brush seal ring divided body 26b. And brush holder divided body 50b, brush seal ring divided body 26c and brush holder divided body 50c, and brush seal ring divided body 26d and brush holder divided body 50d. The shaft seal device can be easily and accurately fixed to a large rotating machine having the pressure vessel 14 or the pressure partition wall 16 divided into two, and the inner diameter portion of the thin wire bundle 31 can be rotated. Since the gap G between the outer peripheral surface of the shaft 12 can be set extremely small and accurately, the leakage of the working fluid F is greatly reduced, and the steam turbine It is possible to realize a heat increase.

Sixth embodiment
Next, FIG. 10 is a diagram showing a shaft seal device according to a sixth embodiment of the present invention. Note that the same reference numerals are given to the same components as those in FIG. 2 of the first embodiment, and detailed description thereof will be omitted.

  The sixth embodiment is a groove formed on the inner peripheral surface of the pressure partition wall 16 or the pressure vessel 14 as a structure for fixing the shaft seal device 25 to the pressure partition wall 16 or the pressure vessel 14, and is a high-pressure side or a low-pressure side. In this embodiment, the shaft seal device 25 is fixed using an annular groove which is not opened but is opened only on the inner diameter side.

  In FIG. 10, the pressure partition 16 is divided into two as in the fifth embodiment. First, the brush holder 27 that holds the channel-type brush seal ring 26 in the annular groove 52 of the lower half pressure partition 16 (not shown). 28, the lower half is fitted. Next, after setting the rotating shaft 12, the upper half of the brush holders 27 and 28 holding the channel type brush seal ring 26 is fitted into the annular groove 52 of the pressure partition 16b of the upper half.

  In this way, the channel type seal ring 26 can be fixed by fitting the brush holders 27 and 28 holding the channel type brush seal ring 26 into the annular groove 52. Also in the sixth embodiment, the outer peripheral surfaces of the high pressure side brush holder 27 and the low pressure side brush holder 28 constituting the brush holder are the position reference surfaces 36 and 38 in the radial direction, respectively. As in the first and second embodiments, the outer side surfaces of the low-pressure side brush holder 28 are axial position reference surfaces 37 and 39, respectively.

  According to the sixth embodiment configured as described above, the installation position where the channel-type seal ring 26 is planned can be obtained by merely fitting the brush holders 27 and 28 into the annular groove 52 without requiring mounting bolts or the like. In addition, the gap G between the inner diameter portion of the thin wire bundle 31 and the outer peripheral surface of the rotary shaft 12 can be set very small and accurately, so that the leakage of the working fluid F is greatly reduced. To improve the heat of the steam turbine. Further, when the thin wire bundle 31 is worn, there is no assembly bolt, so that it is easy to remove and there is an advantage that the replacement work of the channel type brush seal ring 26 is facilitated.

Seventh embodiment
Next, FIG. 11 is a diagram showing a shaft seal device according to a seventh embodiment of the present invention.
The first to sixth embodiments described so far are embodiments in which the channel-type brush seal ring 26 is installed in the pressure partition wall 16 or the pressure vessel 14, but this seventh embodiment is the pressure partition wall 16 or the pressure vessel. 14 is a combination of a labyrinth seal ring that is a seal device that prevents the working fluid F from leaking from the high-pressure side to the low-pressure side along the rotary shaft 12 and the channel-type brush seal ring 26. It is the configured embodiment.

  In FIG. 11, reference numeral 54 denotes a labyrinth seal ring. A plurality of annular seal fins 55 are provided on the low pressure side in the inner diameter portion of the labyrinth seal ring 54. A gap G ′ having a predetermined size is set between the tips of the seal fins 54 and the outer peripheral surface of the rotary shaft 12.

  A plurality of bolt holes 56 are formed in the circumferential direction so as to penetrate the high-pressure side brush holder 27 and the low-pressure side brush holder 28 that are concentric with and parallel to the channel-type brush seal ring 26. The bolt hole 56 is inserted with a mounting bolt 57 for fixing the high pressure side brush holder 27 and the low pressure side brush holder 28 sandwiching the channel type brush seal ring 26 to the labyrinth seal ring 54. On the side surface of the labyrinth seal ring 54 on the high pressure chamber side, an annular notch groove 60 into which the brush holders 27 and 28 are fitted is formed. A female screw hole 61 into which the mounting bolt 57 is screwed is formed on the bottom surface of the notch groove 60.

  The channel type brush seal ring 26 is dimensioned with reference to the position reference surfaces 36, 38, 39 provided on the high pressure side brush holder 27 and the low pressure side brush holder 28, as in the first to third embodiments. In spite of the low-precision channel-type brush seal ring 26, it is possible to fix the labyrinth seal ring 54 concentrically and in parallel at a predetermined position with high accuracy. Further, by processing the inner diameter portion of the thin wire bundle 31 with the radial position reference surfaces 36 and 38 as a reference and precisely finishing the inner diameter, the gap G with the rotary shaft 12 can be set accurately. The gap G can be set accurately within a range of 0.0 mm, and the gap G can be set extremely small and accurately, so that the sealing effect can be enhanced and leakage of the working fluid F can be significantly reduced. .

  In addition, the channel-type brush seal ring 26 arranged on the high-pressure side has a higher leakage reduction effect than the adjacent labyrinth seal ring 54, and leakage of the working fluid F even if the rotating shaft 12 is shaken. Can be prevented. On the other hand, the seal fin 55 of the labyrinth seal ring 54 arranged on the low pressure side suppresses a rapid increase in the leakage amount of the working fluid F even if the thin wire bundle 31 of the channel type brush seal ring 26 is worn or damaged. can do.

  As described above, in this embodiment, the channel-type brush seal ring 26 and the labyrinth seal ring 54 can be combined to form a two-stage shaft seal, and a larger pressure difference can be partitioned.

  In particular, the channel-type brush seal ring 26 according to the present embodiment has an advantage that it can be reliably installed at a predetermined position when it is additionally installed on the existing labyrinth seal ring 54.

  In the above embodiment, the monolithic channel-type brush seal ring 26 is attached to the monolithic labyrinth seal ring 54. However, the labyrinth seal ring 54 may be divided. In particular, in a rotating machine such as a large steam turbine, the labyrinth seal ring 54 shaft seal device 25 that is divided in the circumferential direction may be used. In this case, a dovetail groove extending in the circumferential direction is formed on the inner peripheral surface of the pressure partition wall 16, and a plurality of springs are arranged in the dovetail groove. The labyrinth seal ring 54 has a radius by the elastic force of the spring. It is biased inward.

  When the channel-type seal ring 26 is additionally installed in a rotary machine having the labyrinth seal ring 54 of this type and already in operation, the channels are equally divided in the circumferential direction as in the fifth embodiment. In the case of a mold seal ring, the channel-type seal ring 26 can be easily installed, and a larger pressure difference can be partitioned by the configuration of the two-stage shaft seal.

  DESCRIPTION OF SYMBOLS 10 ... Axial flow turbine, 12 ... Rotary shaft, 14 ... Pressure vessel, 15 ... High pressure chamber, 16 ... Pressure partition, 17 ... Low pressure chamber, 22 ... Nozzle part, 25 ... Sealing device, 26 ... Channel type seal ring, 27 ... High pressure side brush holder, 28 ... Low pressure side brush holder, 30 ... Channel portion, 31 ... Fine wire bundle, 36 ... Radial position reference plane, 37 ... Axial position reference plane, 38 ... Radial position reference plane, 39 ... Axis position reference plane, 42 ... Tightening bolt, 45 ... Filler

Claims (9)

In a shaft seal device that seals between a high pressure region and a low pressure region adjacent to each other in the axial direction of the rotating shaft of a rotating machine,
The thin wire bundle is folded by placing a metal core on the center in the longitudinal direction of the belt-like thin wire bundle, and covering the thin metal wire bundle between the channel portion and the metal core that is folded in the longitudinal direction by covering the thin wire bundle with a belt-like thin plate. Forming a channel brush, and an inner volume channel type brush seal ring in which the channel brush is formed in an annular shape so that the channel portion is on the outer peripheral side,
The high pressure side brush holder facing the high pressure side region and the low pressure side brush holder facing the low pressure side region, and the channel-type brush seal ring on the abutment surface of the high pressure side brush holder and the low pressure side brush holder A groove that forms a space that is accommodated by the channel portion, and an annular brush holder that sandwiches and fixes the channel-type brush seal ring between the high-pressure side brush holder and the low-pressure side brush holder,
The high-pressure side brush holder and / or the low-pressure side brush holder have a position reference surface that forms a fitting structure with a pressure bulkhead or a pressure vessel at an installation position and determines an installation position of the channel-type brush seal ring. A shaft seal device. In a shaft seal device that seals between a high pressure region and a low pressure region adjacent to each other in the axial direction of the rotating shaft of a rotating machine,
A labyrinth seal ring that has a plurality of annular fins set with a predetermined gap between the surface of the rotating shaft and is installed in a partition that divides the high-pressure region and the low-pressure region;
The thin wire bundle is folded by placing a metal core on the center in the longitudinal direction of the belt-like thin wire bundle, and covering the thin metal wire bundle between the channel portion and the metal core that is folded in the longitudinal direction by covering the thin wire bundle with a belt-like thin plate. Forming a channel brush, and an inner volume channel type brush seal ring in which the channel brush is formed in an annular shape so that the channel portion is on the outer peripheral side,
The high pressure side brush holder facing the high pressure side region and the low pressure side brush holder facing the low pressure side region, and the channel-type brush seal ring on the abutment surface of the high pressure side brush holder and the low pressure side brush holder A groove for forming a space for receiving the channel portion is formed, the channel-type brush seal ring is sandwiched between the high-pressure side brush holder and the low-pressure side brush holder, and the channel is concentric and parallel to the labyrinth seal ring. An annular brush holder for holding the mold brush seal ring,
The high-pressure brush holder and / or the low-pressure brush holder has a position reference surface that forms a fitting structure with the labyrinth seal ring and determines an installation position of the channel-type brush seal ring. apparatus.   The high-pressure side brush holder and / or the low-pressure side brush holder have an outer peripheral surface in which dimensional accuracy necessary for accurate positioning is secured in advance and a side surface opposite to the butted surface, and the outer peripheral surface is positioned in the radial direction. The shaft sealing device according to claim 1, wherein a reference surface is formed, and the side surface forms an axial position reference surface.   The reference position in the radial direction of the high-pressure side brush holder and / or the low-pressure side brush holder is a reference surface that sets a gap between the inner diameter portion of the thin wire bundle of the channel-type brush seal ring and the rotating shaft. The shaft seal device according to claim 3, wherein   5. The brush holder according to claim 1, wherein the brush holder has an annular fin protruding in a radial direction of the rotation shaft and having a predetermined gap between the surface and the rotation shaft surface. A shaft seal device according to any one of the above items.   The shaft seal device according to any one of claims 1 to 5, wherein the high-pressure side brush holder and the low-pressure side brush holder are integrally fastened by a fastening bolt.   A heat-resistant filler is filled between an inner surface of a groove of the high-pressure side brush holder and the low-pressure side brush holder that form a space for accommodating the channel portion and the channel portion. Item 7. The shaft seal device according to any one of items 1 to 6.   The shaft seal device according to any one of claims 1 to 7, wherein the brush holder is fixed by being fitted into an annular groove formed in a partition wall, a pressure vessel, or the labyrinth seal ring.   The shaft seal device according to any one of claims 1 to 8, wherein the channel-type brush seal ring and the brush holder are composed of a divided body that is equally divided into a plurality of portions in the circumferential direction.

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