Technical field
[0001]
　The present invention is provided around the rotation shaft of the steam turbine and gas turbine, to a shaft sealing mechanism for reducing the leakage of fluid leaking to the low pressure side from the high pressure side.
Background technique
[0002]
　Conventionally, around the rotation shaft of the steam turbine or gas turbine, for the purpose of suppressing the loss of the driving force, the shaft sealing mechanism for reducing the leakage of fluid leaking to the low pressure side from the high-pressure side is provided . Such shaft sealing mechanism is adapted a flat thin sheet seal piece having a width in the axial direction, an annular seal structure disposed in multilayer on the rotating shaft circumferential direction. Then, the outer peripheral side base end portion of the thin sheet seal pieces, while being fixed to the annular seal housing, the inner circumference side tip of the thin seal piece is in sliding contact with a predetermined preload to the outer peripheral surface of the rotating shaft. Thus, in the shaft sealing mechanism, it is possible to partition a plurality of thin seal strips arranged in an annular radially outward of the rotating shaft as a boundary, the space around the rotating shaft, into a high pressure side region and a low pressure side region .
[0003]
　Therefore, when the rotation of the rotary shaft is stopped, the inner circumference side tip of the thin seal pieces are in contact with a predetermined preload to the outer peripheral surface of the rotating shaft. On the other hand, when the rotary shaft is rotating, a pressure difference due to relative displacement of the pressure distribution between the upper and lower surfaces of the thin sheet seal piece, by the dynamic pressure effect of the fluid caused by the rotation of the rotary shaft, thin seal piece by flexing the inner circumferential side leading end portion thereof, it emerged from the outer peripheral surface of the rotary shaft, the non-contact. This prevents wear and heat generation of the thin seal piece and the rotary shaft. In the thin seal pieces, the surface facing the rotating shaft and the lower surface, and the opposite side of the lower surface and upper surface.
[0004]
　Then, such as a conventional shaft sealing mechanism, for example, disclosed in Patent Document 1.
CITATION
Patent Literature
[0005]
Patent Document 1: U.S. Patent Application Publication No. 2013/0154199 Pat
Summary of the Invention
Problems that the Invention is to Solve
[0006]
　Here, in the shaft seal mechanism, the low pressure side and high pressure side of the thin seal piece, and a predetermined amount of clearance to be provided, respectively. By adjusting the gap amount of the low pressure side gap and the high pressure side gap, by generating the pressure differential thin seal pieces, it is possible to provide a levitation force to the thin seal pieces. In other words, the gap control in the low pressure side gap and the high pressure side gap, in terms of floating the thin seal pieces has become a very important factor.
[0007]
　However, the gap amount described above, despite the small amount, and the thin sealing strips are formed by a plurality of support members provided on the periphery. Accordingly, even if previously correctly set their gap amount, the machining error or assembling error of the thin seal strips and the support member, the actual gap amount at the time of assembling, it is possible to obtain a stable flying force it may not be an appropriate clearance amount.
[0008]
　At this time, the actual gap amount is, if becomes smaller than the appropriate clearance volume will be disturbed pressure distribution and pressure difference, with respect to thin seal pieces, pressing of the direction opposite to the direction of action of the lifting force forces may act. Thus, pressing force to be impose inner circumference side tip, when acting on the thin seal pieces, the inner circumferential side distal end portion, will contact with the rotating shaft, there is a risk of wear.
[0009]
　Accordingly, the present invention has been made to solve the above problems, even pressing force to the thin seal piece acts, and suppress deformation due to the pressing force, preventing wear due to contact with the rotary shaft in the thin seal strip and to provide a shaft sealing mechanism that can be.
Means for Solving the Problems
[0010]
　Shaft sealing mechanism according to a first invention for solving the above-mentioned problems,
　by being provided in an annular space formed between the fixed portion and the rotary shaft, the annular space into a high pressure side region and a low pressure side region partitioned by the in shaft seal mechanism so as to prevent fluid in the annular space from the high pressure side region flowing in the rotation axis direction toward the lower pressure side area,
　of the annular it is provided on the inner peripheral portion of the stationary seal a housing,
　closed while the outer peripheral side base end portion is fixed to the seal housing, the inner circumference side tip becomes a free end so as to form an outer peripheral surface and an acute angle of said rotary shaft, the width in the axial direction and, a plurality of thin seal strips to be stacked in a circle rotating shaft circumferential direction,
　the way the high pressure side gap in the rotation axis direction between the seal housing is formed, the thin plate opposite to the high-pressure side region high pressure seal piece A high pressure side annular plate provided adjacent to the side edges,
　the low pressure side gap in the rotation axis direction between the low pressure side side edge portion of the thin seal pieces opposed to the low pressure side region and the seal housing is formed as will be, and the low-voltage side annular plate which is sandwiched between the low pressure side side edge portion and the seal housing,
　a high pressure-side stepped portion formed on the high pressure side side edge portion,
　the low pressure side side edge and the low-voltage side stepped portion formed on parts,
　the formed on the high pressure side plate, and a high-pressure-side locking portion for locking the high pressure side stepped portion from the rotational axis radially inward,
　are formed on the low pressure side plate, wherein and a low-pressure-side locking portion for locking the low-pressure side stepped portion from the rotation axis radially inwardly
　, characterized in that.
[0011]
　Shaft sealing mechanism according to a second invention for solving the above problems,
　the The inclined surface of the inclined end face of the high pressure side step portion and the high pressure side locking portion, engages in the rotational axis radially,
　the low-pressure side step the inclined end face parts and the inclined surface of the low-pressure-side locking portion, engages in the rotational axis radially
　, characterized in that.
[0012]
　Shaft sealing mechanism according to a third invention for solving the above problems,
　by being provided in an annular space formed between the fixed portion and the rotary shaft, the annular space into a high pressure side region and a low pressure side region partitioned by the in shaft seal mechanism so as to prevent fluid in the annular space from the high pressure side region flowing in the rotation axis direction toward the lower pressure side area,
　of the annular it is provided on the inner peripheral portion of the stationary seal a housing,
　closed while the outer peripheral side base end portion is fixed to the seal housing, the inner circumference side tip becomes a free end so as to form an outer peripheral surface and an acute angle of said rotary shaft, the width in the axial direction to the so low pressure side gap in the rotation axis direction between the low pressure side region facing the low pressure side side edge portion and the seal housing is formed, a plurality of thin plates are laminated in a ring on the rotary shaft circumferential direction and a seal piece,
　before And the low-voltage side stepped portion formed on the low pressure side side edge portion,
　is formed in the seal housing, and a low-pressure-side locking portion for locking the low-pressure side stepped portion from the rotation axis radially inwardly
　, characterized in that .
[0013]
　Shaft sealing mechanism according to a fourth invention for solving the above problems,
　the so the low pressure side gap between the low pressure side side edge portion and the seal housing is formed, the said low pressure side side edge seal comprising a low-pressure side annular plate which is interposed between the housing and
　the low-pressure side latching section, in the rotation axis radially inward of the inner circumferential side distal end portion of the low pressure side plate, engaging the low pressure side step portion to stop
　, characterized in that.
[0014]
　Shaft sealing mechanism according to a fifth invention for solving the above problems,
　the the low pressure side step portion inclined end face and the inclined surface of the low-pressure side locking portion, engages in the rotational axis radially
　, characterized in that .
Effect of the Invention
[0015]
　Therefore, according to the shaft sealing mechanism according to the present invention, by engaging the thin seal pieces from the rotational axis radially inward pressing force in the thin seal piece also acts to suppress the deformation due to the pressing force , it is possible to prevent wear due to contact with the rotary shaft in the thin seal pieces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016]
FIG. 1 is a schematic diagram of a shaft sealing mechanism according to the present invention.
It is an axial sectional view of a shaft sealing mechanism according to FIG. 2 the present invention.
3 is a diagram of the disassembled state of the support structure of the thin seal pieces.
[Figure 4] a detailed view of a shaft sealing mechanism according to Example 1, it is a front view of the thin seal pieces.
[5] a detailed view of a shaft sealing mechanism according to the second embodiment, a front view of a thin seal pieces.
[6] a detailed view of a shaft sealing mechanism according to the third embodiment, a front view of a thin seal pieces.
DESCRIPTION OF THE INVENTION
[0017]
　About an axis seal mechanism according to the present invention will be described in detail with reference to the drawings.
Example
[0018]
　As shown in FIG. 1, the shaft sealing mechanism 11 according to the present invention is rotated, for example, be one that is applied to a steam turbine or gas turbine, the fixing portion such as a cabin casing and vanes (stationary portion) 12 and It is provided in the annular space 14 formed between the shaft 13.
[0019]
　Specifically, as shown in FIGS. 1 and 2, the inner peripheral portion of the fixing portion 12, as the seal housing 21 which forms a housing of the shaft sealing mechanism 11, along the circumferential direction of the rotary shaft 13, cyclic It is provided to. Further, the inner peripheral portion of the seal housing 21, the annular groove 21a is formed, inside the annular groove 21a, a large number of thin seal strips 22, are arranged along the circumferential direction of the rotary shaft 13 there.
[0020]
　Then, the outer peripheral side base end portion 22a of the thin seal strips 22, while being fixed in the annular groove 21a, the inner circumference side tip 22b of the thin seal piece 22, sliding in a predetermined preload on the outer peripheral surface of the rotary shaft 13 We are in contact with each other. At this time, thin seal piece 22, the inner circumference side tip 22b serving as a free end, with an inclination in the rotating direction with respect to the outer circumferential surface of the rotary shaft 13, so that the outer peripheral surface and the angle is an acute angle to, are located. Incidentally, in the thin seal member 22 which is inclined support is a surface facing the rotating shaft 13 and a lower surface, the opposite surface of the lower surface and upper surface.
[0021]
　That is, in the annular space 14 formed between the fixed portion 12 and the rotary shaft 13, fluid G, such as steam or combustion gas, toward the low-pressure side from the high-pressure side flows in the axial direction of the rotation at 13 ing. In contrast, the shaft sealing mechanism 11, a thin seal piece 22 has a annular seal structure disposed in multilayer in the circumferential direction of the rotary shaft 13, and a number of thin sheet seal piece 22 disposed in the annular border the annular space 14, a high pressure side region serving as a fluid flow direction upstream side, by partitioning into a low pressure side region serving as a fluid flow direction downstream side, the amount of leakage of the fluid G leak to the low pressure side region from the high pressure side region It has become a thing to reduce.
[0022]
　Here, as shown in FIGS. 2 and 3, thin seal strip 22 is a flexible material having flexibility, and is formed in a flat plate shape having a width dimension in the axial direction of the rotary shaft 13 . In particular, thin seal pieces 22, together form a T-shaped plate width of the base end side (outer peripheral side base end portion 22a) is wider than the plate width of the front end side (inner circumference side tip 22b), variable are thinned enough to exert FLEXIBLE, a certain amount of small gap in the circumferential direction of the rotating shaft 13 are arranged in an annulus.
[0023]
　Then, the base end side of the thin seal piece 22, the pair of right and left retainers 23, 24 for retaining the annular arrangement of the thin seal piece 22 is sandwiched so as to surround the plate width direction on both sides. Further, the retainer 23 is fitted into the annular groove 21a of the seal housing 21.
[0024]
　Further, the high pressure side and low pressure side of the thin seal piece 22, the high-pressure-side plate 25 and the low-pressure-side plate 26 serving as the guide plate of the fluid G is provided.
[0025]
　Specifically, the left side facing the high pressure side region of the thin seal piece 22 (the side positioned on the left side of FIG. 2 and 3), the annular high pressure side plate 25 is disposed. The high-pressure-side plate 25 is provided adjacent to the high pressure side side edge portion 22c facing the high pressure side region of the thin seal piece 22, it is sandwiched between the high pressure side side edge portion 22c and the retainer 23 there.
[0026]
　At this time, the inner circumference side tip 25a of the high-pressure-side plate 25, while extending to the opening edge portion of the annular groove 21a, does not reach the inner peripheral side leading end portion 22b of the thin seal pieces 22. Furthermore, a high pressure side surface 21b facing the high pressure side region of the annular groove 21a, between the high pressure side plate 25, in the axial direction of the rotary shaft 13 (the fluid flow direction, the sealing strip plate width direction), a certain amount of high pressure side gap δH is formed.
[0027]
　Thus, by providing the high-pressure-side plate 25, the inner circumference side tip 22b of the thin seal piece 22, than the inner circumference side tip 25a of the high-pressure-side plate 25, disposed radially inwardly of the rotary shaft 13 since the fluid G that has flowed from the high pressure side region, it flows from the front end side of the thin seal pieces 22.
[0028]
　On the other hand, the right side facing the low pressure side region of the thin seal piece 22 (the side located on the right side of FIG. 2 and 3), the annular low pressure side plate 26 is disposed. The low-pressure-side plate 26 is provided adjacent to the low pressure side side edge portion 22d facing the low pressure side region of the thin seal pieces 22, its low pressure side side edge portion 22d, the low pressure in the retainer 24 and the annular groove 21a It is sandwiched between the low pressure side side surface 21c facing the side region.
[0029]
　At this time, the inner circumference side tip 26a of the low-pressure-side plate 26 is not reach the inner peripheral side leading end portion 22b of the opening edge portion and the thin seal piece 22 of the annular groove 21a, the inner peripheral side of the high-pressure-side plate 25 It is arranged radially outward of the rotating shaft 13 than the tip portion 25a. That is, the length of the low-pressure-side plate 26 is shorter than the length of the high-pressure-side plate 25. Further, between the low pressure side side surface 21c and the low pressure side side edge portion 22d of the annular groove 21a, in the axial direction of the rotary shaft 13, a certain amount of the low-pressure side gap δL it is formed.
[0030]
　Thus, by providing the low-pressure-side plate 26, between the low pressure side side surface 21c and the low pressure side side edge portion 22 d, it is possible to form the low pressure side gap [delta] L. The low-pressure side gap [delta] L is to be formed by the thickness of the low-pressure-side plate 26, by adjusting the thickness of the low-pressure-side plate 26, it is possible to set the gap amount of the low pressure side gap [delta] L.
[0031]
　Further, it is possible to set the in accordance with the gap amount of the high pressure side gap δH and the low pressure side gap [delta] L, pressure distribution by the fluid G formed on the upper and lower surfaces of the thin seal pieces 22. Furthermore, in accordance with the magnitude relationship between the gap amount of the gap amount and the low pressure side gap δL of the high pressure side gap delta] H, the magnitude of the pressure difference due to relative displacement of the pressure distribution between the upper and lower surfaces of the thin seal pieces 22 (floating the force), can be set.
[0032]
　Incidentally, in the shaft sealing mechanism 11 according to the present invention, a radial gap amount between the inner circumference side tip 26a and the outer peripheral surface of the rotary shaft 13 of the low pressure side plate 26, the inner circumference side tip of the high-pressure-side plate 25 than the radial gap amount between the parts 25a and the outer peripheral surface of the rotary shaft 13, by increasing, so as to obtain the stable floating force.
[0033]
　From the above, when the rotation of the rotary shaft 13 is stopped, the inner circumference side tip 22b of the thin seal piece 22 comes into contact with a predetermined preload to the outer peripheral surface of the rotary shaft 13. On the other hand, when the rotating shaft 13 is rotating, by a pressure difference due to relative displacement of the pressure distribution between the upper and lower surfaces of the thin plate sheet piece 22, the dynamic pressure effect of the fluid G produced by the rotation of the rotary shaft 13, floating force acts on the thin seal pieces 22. Thus, is bent thin sheet seal pieces 22, their inner circumference side tip 22b will bubble up from the outer peripheral surface of the rotary shaft 13 in a non-contact, wear and heat generation of the rotary shaft 13 and thin seal piece 22 is prevented that. At the same time, by thin seal piece 22 became non-contact state with respect to the rotating shaft 13, leakage of the fluid G flowing from the high pressure side region toward the low pressure side region is reduced.
[0034]
　Here, as shown in FIG. 4, the high pressure side side edge 22c and the low-side edge portion 22d of the thin seal pieces 22, stepped portions (the high-pressure side step portion) 31 and the step portion (low pressure side step portion) 32 There has been formed. These stepped portions 31 and 32, the side edge portion 22c, the diametrically medial section of the 22d is disposed (longitudinally intermediate portion), a plate width of the radially inner portion than the step portion 31 of the thin seal piece 22 It was constant, and, so as to form a thin seal strip 22 in a tapered shape, and forms a step forming. Then, the step of the stepped portions 31 and 32 is formed by the inclined end face. The inclined end face is oriented in the radial direction inner side of the rotary shaft 13, the seal piece plate width direction outer inclined end portion, the seal piece plate width direction inside inclined end portion, located radially inwardly of the rotary shaft 13 I am inclined to.
[0035]
　In contrast, on the inner circumference side tip 25a of the high-pressure-side plate 25, the engaging portion (high pressure side latching portion) 25b is formed. Then, the locking portion 25b, in the plate width direction of the thin seal pieces 22 are formed so as to protrude toward the high pressure side plate 25 on the high pressure side side edge portion 22c, on its protruding end portion, an annular inclined surface is formed. The inclined surface is oriented radially outward of the rotating shaft 13, the seal piece plate width direction inside inclined end, the seal piece plate widthwise outer beveled edge, located radially outward of the rotary shaft 13 I am inclined to.
[0036]
　Further, on the inner circumference side tip 26a of the low-pressure-side plate 26, the locking portion (low pressure side latching portion) 26b is formed. Then, the locking portion 26b, in the plate width direction of the thin seal pieces 22, and the low pressure side plate 26 is formed so as to protrude toward the low pressure side side edge portion 22 d, the the protruding tip, an annular inclined surface is formed. The inclined surface is oriented radially outward of the rotating shaft 13, the seal piece plate width direction inside inclined end, the seal piece plate widthwise outer beveled edge, located radially outward of the rotary shaft 13 I am inclined to.
[0037]
　That is, the inclined surface of the inclined end face and the locking portion 25b of the stepped portion 31 in the radial direction of the rotary shaft 13, has a engageable with the inclined surface of the inclined end face and the locking portion 26b of the stepped portion 32 , in the radial direction of the rotating shaft 13, and it can engage. Thus, the engaging portion 25b to be engaged, between the inclined surface and the inclined end surface of the stepped portions 31 and 32 of 26b is prevented escape in the radial direction of the rotary shaft 13 is achieved.
[0038]
　From the above, for example, by the pressure of the fluid G from the high pressure side region when turbine operation toward the lower pressure side area, or thin seal piece 22 is pushed toward the low pressure side region, after assembly of the shaft sealing mechanism 11, mechanism assembly errors in or generated, the gap amount of the low pressure side gap [delta] L is stable becomes smaller than the gap amount can be obtained levitation force (e.g., delta] H> [delta] L), a pressure distribution is formed in a thin plate sealing piece 22 and, the pressure differential acting on the thin seal piece 22 is disturbed. Thus, the thin seal piece 22, the pressing force in the opposite direction to the direction of action of the lifting force is to act, the inner peripheral side leading end portion 22b is, than the preload force during the rotation stop of the rotary shaft 13 even large pressure, deformation occurs of being pressed towards the rotary shaft 13.
[0039]
　However, the shaft sealing mechanism 11 according to the present invention, the engaging portion 25b, and 26b provided on the high pressure side plate 25 and the low pressure side plate 26, by the locking portion 25b, 26, stepped portion 31 of the thin seal pieces 22, 32, by allowing the locking direction from the radially inner side of the rotary shaft 13 radially outward, even if a large pressing force than the preload force acts on the thin seal pieces 22, stepped portions 31 and 32 are engaged since caught stopping part 25b, to 26b, it is possible to suppress deformation toward the rotation shaft 13 in the thin seal pieces 22. Accordingly, the inner circumference side tip 22b of the thin seal pieces 22, without contacting the rotary shaft 13, it is possible to maintain a non-contact state, it is possible to prevent wear of the thin seal pieces 22.
[0040]
　Further, the engaging portion 25b, and the inclined surface of the 26b, the inclined end surface of the stepped portions 31 and 32, in the radial direction of the rotary shaft 13, by which enables engagement, if, thin seal piece 22 is the high pressure side or even when assembled is inclined to the low pressure side, it is possible to always lock the stepped portions 31 and 32 engaging portion 25b, by 26b.
[0041]
　Furthermore, the shaft sealing mechanism 11 according to the present invention, among the components of the existing sealing mechanisms, thin seal piece 22, the high-pressure-side plate 25 and, only to the low pressure side plate 26, so that applying a shape change . Thus, for large member such as a seal housing 21 requires no shape change significantly without having to design changes, it is possible to prevent wear of the thin seal piece 22 by the pressing force.
[0042]
　In the embodiment described above has a configuration for locking the thin seal strip 22 by the high-pressure-side plate 25 and the low pressure side plate 26, as shown in FIGS. 5 and 6, the seal housing 21 to thin seal piece 22 it may be configured to be locked by.
[0043]
　Therefore, as shown in FIG. 5, the low pressure side side edge portion 22d of the thin seal pieces 22, stepped portions (the low pressure side step portion) 33 is formed. The stepped portion 33, than the inner circumference side tip 26a of the low-pressure-side plate 26 is disposed radially inwardly of the rotary shaft 13, and has a cut-out shape cutting out a low pressure side side edge portion 22d. Then, the step of the stepped portion 33 is formed by the inclined end face. The inclined end face is oriented in the radial direction inner side of the rotary shaft 13, the seal piece plate width direction outer inclined end portion, the seal piece plate width direction inside inclined end portion, located radially inwardly of the rotary shaft 13 I am inclined to.
[0044]
　In contrast, in the low pressure side side surface 21c of the seal housing 21, the locking portion (low pressure side latching portion) 21d is formed. Then, the engaging portion 21d, in the plate width direction of the thin seal pieces 22, and the low pressure side side 21c is formed so as to protrude toward the low pressure side side edge portion 22 d, the the protruding tip, an annular inclined surface is formed. The inclined surface is oriented radially outward of the rotating shaft 13, the seal piece plate width direction inside inclined end, the seal piece plate widthwise outer beveled edge, located radially outward of the rotary shaft 13 I am inclined to.
[0045]
　That is, the engaging portion 21d, rather than the inner circumference side tip 26a of the low-pressure-side plate 26 is disposed radially inwardly of the rotary shaft 13, the inclined surface and the inclined end surface of the stepped portion 33 of the engaging portion 21d , in the radial direction of the rotating shaft 13, and it can engage. Thus, in between the inclined end face of the inclined surface and the step portion 33 of the engaging portion 21d of the engagement, preventing leakage in the radial direction of the rotary shaft 13 is achieved.
[0046]
　Accordingly, an engagement portion 21d provided on the seal housing 21, by the engagement portion 21d, the stepped portion 33 of the thin seal pieces 22, to be retained towards the radially inner side of the rotary shaft 13 radially outward Accordingly, even when acting large pressing force than the preload force to the thin seal pieces 22, since the step portion 33 is caught by the engaging portion 21d, it is possible to suppress deformation toward the rotation shaft 13 in the thin seal piece 22 it can. Accordingly, the inner circumference side tip 22b of the thin seal pieces 22, without contacting the rotary shaft 13, it is possible to maintain a non-contact state, it is possible to prevent wear of the thin seal pieces 22.
[0047]
　Furthermore, long-term by providing the engaging portion 21d in the seal housing 21 to be a large member, it is possible to improve the rigidity of the engaging portion 21d, the engagement between the engaging portion 21d and the stepped portion 33 it can be maintained over a.
[0048]
　Further, as shown in FIG. 6, the low pressure side side edge portion 22d of the thin seal pieces 22, stepped portions (the low pressure side step portion) 34 is formed. The step portion 34 is disposed radially intermediate portion of the low pressure side side edge portion 22 d (longitudinal direction intermediate portion), by recessed toward the plate width direction center side of the thin seal piece 22, thin seal piece 22 so as to form a tapered shape, and forms a step forming. Then, the step of the step portion 34 is formed by the inclined end face. The inclined end face is oriented in the radial direction inner side of the rotary shaft 13, the seal piece plate width direction outer inclined end portion, the seal piece plate width direction inside inclined end portion, located radially inwardly of the rotary shaft 13 I am inclined to.
[0049]
　In contrast, in the low pressure side side surface 21c of the seal housing 21, the locking portion (low pressure side latching portion) 21e is formed. The locking portion 21e, in the plate width direction of the thin seal pieces 22, and the low pressure side side 21c is formed so as to protrude toward the low pressure side side edge portion 22 d, the the protruding tip, an annular inclined surface is formed. The inclined surface is oriented radially outward of the rotating shaft 13, the seal piece plate width direction inside inclined end, the seal piece plate widthwise outer beveled edge, located radially outward of the rotary shaft 13 I am inclined to.
[0050]
　That is, the inclined surface and the inclined end surface of the stepped portion 34 of the locking portion 21e and, in the radial direction of the rotating shaft 13, and can engage. Thus, in between the inclined surface and the inclined end surface of the stepped portion 34 of the locking portion 21e to be engaged, preventing leakage in the radial direction of the rotary shaft 13 is achieved.
[0051]
　Therefore, the engaging portion 21e is provided on the seal housing 21, by the locking portion 21e, a step portion 34 of the thin seal pieces 22, to be retained towards the radially inner side of the rotary shaft 13 radially outward Accordingly, even when applied to a large pressing force it is thin seal piece 22 than the preload force, since the step portion 34 is caught by the locking portion 21e, is possible to suppress deformation toward the rotation shaft 13 in the thin seal piece 22 it can. Accordingly, the inner circumference side tip 22b of the thin seal pieces 22, without contacting the rotary shaft 13, it is possible to maintain a non-contact state, it is possible to prevent wear of the thin seal pieces 22.
[0052]
　Furthermore, long-term by providing the engaging portion 21e on the seal housing 21 to be a large member, it is possible to improve the rigidity of the locking portion 21e, an engagement state between the engaging portion 21e and the step portion 34 it can be maintained over a. Moreover, it is not necessary to provide a low pressure side plate 26, not only it is possible to simplify the structure of the shaft sealing mechanism 11, it is possible to reduce the manufacturing cost of the shaft sealing mechanism 11.
Industrial Applicability
[0053]
　In the shaft sealing mechanism according to the present invention, to prevent breakage of the thin sealing strips according to the pressing force, it is possible to reduce the extension of the sealing strip lifetime in continuous operation of the turbine can be utilized very usefully .
DESCRIPTION OF SYMBOLS
[0054]
　11 shaft sealing mechanism, 12 fixing unit, 13 rotation shaft, 14 an annular space 21 seal housing, 21a annular groove, 21b pressure side surface, 21c low pressure side side, 21d, 21e engaging portion, 22 thin seal strips, 22a outer circumferential side proximal portion, the peripheral side base end portion 22b, 22c high pressure side side edge portion, 22 d the low pressure side side edge, 23 and 24 retainer, 25 the high pressure side plate, 25a inner circumferential tip, 25b engaging portion, 26 low side plates, 26a inner circumferential tip, 26b engaging portions, 31-34 step portion, G fluid, delta] H high pressure side gap, [delta] L low pressure side gap

The scope of the claims
[Claim 1]
　By being provided in an annular space formed between the fixed portion and the rotary shaft, to partition the annular space into a high pressure side region and a low pressure side region, the low-pressure side in the annular space from the high pressure side region in the shaft sealing mechanism so as to block fluid flow in the rotation axis direction toward the region,
　and an annular seal housing provided in the inner peripheral portion of the fixed portion,
　the outer peripheral side base end portion is fixed to the seal housing on the other hand, the inner circumference side tip becomes a free end so as to form an outer peripheral surface and an acute angle of said rotary shaft, has a width dimension in the rotation axis direction, a plurality of thin plates are laminated in a ring on the rotary shaft circumferential direction and the seal member,
　wherein as the high pressure side gap in the rotation axis direction between the seal housing is formed, an annular provided adjacent to the high pressure side side edge portion of the thin sheet seal piece facing the high pressure side region and the high-pressure side plate
　Wherein as the low pressure side gap in the rotation axis direction between the low pressure side side edge portion and the seal housing at the low pressure side region opposite to the thin seal pieces are formed, said seal housing and said low pressure side side edge portion a low pressure side annular plate which is sandwiched between,
　and a high-pressure-side stepped portion formed on the high pressure side side edge portion,
　and the low-pressure-side stepped portion formed on the low pressure side side edge portion,
　on the high pressure side plate is formed, and a high pressure side latching section for latching the high-pressure side stepped portion from the rotational axis radially inward,
　are formed on the low pressure side plate, the low pressure side of locking the low-pressure side stepped portion from the rotation axis radially inwardly and a locking portion
　shaft sealing mechanism, characterized in that.
[Claim 2]
　In the shaft sealing mechanism according to claim 1,
　the inclined end face of the high-pressure side step portion and the inclined surface of the high-pressure side locking portion is engaged in the rotational axis radially
　and inclined end face of the low pressure side step portion the inclined surface of the low-pressure-side locking portion is engaged in the rotational axis radially
　shaft sealing mechanism, characterized in that.
[Claim 3]
　By being provided in an annular space formed between the fixed portion and the rotary shaft, to partition the annular space into a high pressure side region and a low pressure side region, the low-pressure side in the annular space from the high pressure side region in the shaft sealing mechanism so as to block fluid flow in the rotation axis direction toward the region,
　and an annular seal housing provided in the inner peripheral portion of the fixed portion,
　the outer peripheral side base end portion is fixed to the seal housing on the other hand, the inner circumference side tip becomes a free end so as to form an outer peripheral surface and an acute angle of said rotary shaft, the rotation axis direction has a width dimension, and a low pressure side side edge portion that faces the low-pressure side region , and a plurality of thin seal strips to be stacked in a circle rotating shaft circumferential direction, as the low pressure side gap is formed in the rotation axis direction between the seal housing
　is formed on the low pressure side side edge portion and the low-pressure side step portion,
　the Sea It formed in the housing, and a low-pressure-side locking portion for locking the low-pressure side stepped portion from the rotation axis radially inwardly
　shaft sealing mechanism, characterized in that.
[Claim 4]
　In the shaft sealing mechanism according to claim 3,
　wherein as the low pressure side gap between the low pressure side side edge portion and the seal housing is formed, between the seal housing and the low pressure side side edge portion comprising a low-pressure side annular plate sandwiched,
　the low-pressure side latching section, in the rotation axis radially inward of the inner circumferential side distal end portion of the low pressure side plate, locking the low-pressure side stepped portion
　, characterized in that shaft seal mechanism that.
[Claim 5]
　In the shaft sealing mechanism according to claim 3,
　wherein the low pressure side step portion inclined end face and the inclined surface of the low-pressure side locking portion, engages in the rotational axis radially
　shaft sealing mechanism, characterized in that.