SEALING DEVICE AND ROTATING MACHINE

A sealing device including: a sealing member that is disposed between a rotating member of a rotating machine and a stationary member disposed on the outer side of the rotating member in the radial direction of the rotating member, and that creates a seal between the rotating member and the stationary member; and a biasing member that biases the sealing member toward the radially outer side. The sealing member has a base extending in the circumferential direction of the rotating member, a rib that extends in the circumferential direction and protrudes outward in the radial direction from the base, and a seal fin that extends in the circumferential direction and protrudes inward in the radial direction of the rotating member from the base. The rib has a cut-away part in which the biasing member is disposed between one end and the other end of the rib in the circumferential direction.

TECHNICAL FIELD

The present disclosure relates to a sealing device and a rotating machine.

The present application claims priority based on Japanese Patent Application No. 2022-005086 filed in Japan on Jan. 17, 2022, the contents of which are incorporated herein by reference.

BACKGROUND ART

A rotating machine such as a gas turbine or a steam turbine includes a sealing device that reduces an amount of leakage of a working fluid flowing from a high-pressure side to a low-pressure side in the vicinity of a rotor serving as a rotating member.

PTL 1 discloses a sealing device including a sealing member provided on a radial outer side of a rotor and movable in a radial direction, and a movable sealing member including an elastic body that biases the sealing member toward the radial outer side.

In the sealing device having such a configuration, when the rotating machine is activated and deactivated, the sealing member is biased toward the radial outer side by the elastic body, and a seal gap between the rotor and the movable sealing member is sufficiently secured.

Meanwhile, during the operation of the rotating machine, a working fluid (for example, working steam) on the high-pressure side circulates around a back surface of the sealing member on the radial outer side, so that a back-surface pressure is applied to the sealing member. The back-surface pressure displaces the sealing member to a radial inner side against a biasing force of the elastic body.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

For example, in an upper-half portion of a gas turbine, a steam turbine, or the like, it is necessary to move the sealing member vertically upward against a self-weight of the sealing member by means of the biasing force of the elastic body. Therefore, in order to reliably secure a seal gap between the rotor and the movable sealing member when the rotating machine is activated and deactivated, the biasing force of the elastic body has to be sufficiently large. However, when the biasing force of the elastic body is excessively large, it becomes difficult to displace the sealing member to the radial inner side during the operation of the rotating machine. Since the self-weight of the sealing member increases as the dimension of the sealing member in the radial direction increases, the biasing force of the elastic body has to be increased. Therefore, it tends to become difficult to set the biasing force of the elastic body as the dimension of the sealing member in the radial direction increases.

In addition, for example, in a lower-half portion of a gas turbine, a steam turbine, or the like, during the operation of the rotating machine, the sealing member has to be displaced to the radial inner side against the self-weight of the sealing member and the biasing force of the elastic body. Therefore, in order to reliably displace the sealing member to the radial inner side during the operation of the rotating machine, the biasing force of the elastic body has to be relatively decreased. However, when the biasing force of the elastic body is excessively small, it becomes difficult to secure a seal gap between the rotor and the movable sealing member when the rotating machine is activated and deactivated. Therefore, it tends to become difficult to set the biasing force of the elastic body as the dimension of the sealing member in the radial direction increases.

At least one embodiment of the present disclosure is made in view of the above circumstances, and an object of the present disclosure is to provide a sealing device and a rotating machine capable of securing a seal gap between a rotating member and a sealing member when the rotating machine is activated and deactivated, and of reducing an amount of leakage of a working fluid during the operation of the rotating machine.

Solution to Problem

(1) A sealing device according to at least one embodiment of the present disclosure includes a sealing member that is disposed between a rotating member of a rotating machine and a stationary member disposed on a radial outer side of the rotating member with respect to the rotating member, and that seals between the rotating member and the stationary member; and a biasing member that biases the sealing member toward the radial outer side, in which the sealing member includes a base portion that extends in a circumferential direction of the rotating member, a rib that extends in the circumferential direction and that protrudes from the base portion toward the radial outer side, and a seal fin that extends in the circumferential direction and that protrudes from the base portion toward a radial inner side of the rotating member, and the rib has a notch portion in which the biasing member is disposed between one end and the other end of the rib in the circumferential direction.

(2) A rotating machine according to at least one embodiment of the present disclosure includes the rotating member; the stationary member; and the sealing device having the configuration of (1) described above.

Advantageous Effects of Invention

According to at least one embodiment of the present disclosure, it is possible to provide a sealing device and a rotating machine capable of securing a seal gap between a rotating member and a sealing member when the rotating machine is activated and deactivated, and of reducing an amount of leakage of a working fluid during the operation of the rotating machine.

DESCRIPTION OF EMBODIMENTS

Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. Dimensions, materials, shapes, relative arrangements, and the like of components described as embodiments or illustrated in the drawings are not intended to limit the scope of the present disclosure, but are merely explanatory examples.

For example, an expression representing a relative or absolute arrangement such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric”, or “coaxial” does not strictly represent only such an arrangement, but also a tolerance or a state of being relatively displaced with an angle or a distance to the extent that the same function can be obtained.

For example, an expression such as “identical”, “equal”, or “homogeneous” representing a state where things are equal to each other does not strictly represent only the equal state, but also a tolerance or a state where there is a difference to the extent that the same function can be obtained.

For example, an expression representing a shape such as a quadrangular shape or a cylindrical shape does not represent only a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also a shape including an uneven portion, a chamfered portion, and the like within a range in which the same effect can be obtained.

Meanwhile, the expressions “being provided with”, “comprising”, “including”, or “having” one component are not exclusive expressions excluding the presence of other components.

FIG.1is a diagram for describing a steam turbine as an example of a rotating machine including a sealing device according to some embodiments.

As shown inFIG.1, a steam turbine plant10includes a steam turbine1, a steam supply pipe12that supplies steam S as a working fluid to the steam turbine1from a steam supply source (not shown), and a steam discharge pipe13that is connected to a downstream side of the steam turbine1and that discharges the steam.

As shown inFIG.1, the steam turbine1according to some embodiments includes a casing2, a rotor main body11that rotates around an axis O in the casing2, a rotor3that is connected to the rotor main body11, and a bearing portion4that rotatably supports the rotor main body11around the axis O.

The rotor3includes a rotor main body11and a turbine rotor blade30. The turbine rotor blade30includes a plurality of rotor blade main bodies31that are mounted to the rotor main body11to extend in a radial direction, and a tip shroud34that is connected to a tip portion of each of the plurality of rotor blade main bodies31.

The casing2is a member having a substantially tubular shape provided to cover the rotor3from an outer peripheral side. The casing2is provided with a plurality of stator vane main bodies21that are mounted to extend to a radial inner side toward the rotor main body11. A plurality of the stator vane main bodies21are arranged along a circumferential direction and an axis O direction on an inner peripheral surface25. A hub shroud23that is connected to a tip portion of each of the plurality of stator vane main bodies21is mounted to each of the plurality of stator vane main bodies21.

A main flow path20through which the steam S serving as the working fluid circulates is formed in a region inside the casing2where the stator vane main body21and the rotor blade main body31are arranged.

FIG.2is a schematic cross-sectional view of a casing main body that constitutes the steam turbine ofFIG.1, as seen in a cross section orthogonal to an axis of a rotor.

For convenience of description, in the following description, a radial direction around the axis O is referred to as a radial direction of the rotating member or simply as a radial direction. Similarly, in the following description, a circumferential direction around the axis O is referred to as a circumferential direction of the rotating member or simply a circumferential direction, and an extending direction of the axis O is referred to as an axial direction of the rotating member or simply an axial direction.

The casing2includes a casing main body (casing)51that defines a flow path of the steam S, and an annular vane ring52(refer toFIG.2) that is fixed to an inner peripheral portion of the casing main body51. Further, an inner peripheral portion of the vane ring52is provided with a sealing device100according to some embodiments.

The casing main body51is divided into a casing upper-half portion51A and a casing lower-half portion51B on a plane including the axis O of the rotor3, as shown inFIG.2. Each of the casing upper-half portion51A and the casing lower-half portion51B has a flange portion55A or55B protruding in the radial direction of the rotor3on a surface (split surface54A or54B) to be abutted against the counterpart, respectively. The casing upper-half portion51A and the casing lower-half portion51B are fastened to each other by bolts9in the flange portions55A and55B.

The schematic cross-sectional view shown inFIG.2shows the cross section of the casing main body51at an axial position where the turbine rotor blade30(refer toFIG.1) is disposed on the radial inner side, and the casing main body51at the cross section position is formed in a cylindrical shape.

In addition, the vane ring52is also divided into a vane ring upper-half portion52A and a vane ring lower-half portion52B on a plane including the axis O of the rotor3, as in the casing main body51. The vane ring upper-half portion52A is fixed to the casing upper-half portion51A, and the vane ring lower-half portion52B is fixed to the casing lower-half portion51B. The casing upper-half portion51A and the casing lower-half portion51B are fastened and fixed to each other, so that the vane ring upper-half portion52A and the vane ring lower-half portion52B are connected to each other to form the vane ring52.

The sealing device100according to some embodiments is divided into a sealing device upper-half portion100U and a sealing device lower-half portion100L, as in the casing main body51and the vane ring52.

FIG.3is a front view showing an overall configuration example of the sealing device100according to some embodiments. As shown inFIG.3, the sealing device100according to some embodiments includes a fixed sealing member110and a movable sealing member120that are provided in an annular shape along the tip shroud34connected to each of the tip portions of the plurality of rotor blade main bodies31.

As well shown inFIGS.6A,6B,7A, and7Bto be described later, the sealing device100according to some embodiments is held by a groove portion521formed in the vane ring52and extending in the circumferential direction, and is configured to seal a gap50between the tip shroud34and the vane ring52.

Hereinafter, an example in which the sealing device100according to some embodiments is applied to a sealing device provided between the vane ring52as a “stationary member” of a rotating machine and the tip shroud34as a “rotating member” will be described. However, the sealing device100according to some embodiments can be used as various seals for rotating machines including a gland seal, a stator vane tip seal, a dummy ring seal, and the like.

In the fixed sealing member110, a pair of an upper side member110A and a lower side member110B are respectively disposed on both left and right sides of the rotor main body11. The upper side member110A and the lower side member110B that form a pair are abutted to each other at an abutment surface112. A seal fin is provided on an inner peripheral side of the fixed sealing member110, and leakage of a fluid (in a case where the rotating machine is the steam turbine1, the fluid is steam S) between the fixed sealing member110and the tip shroud34is suppressed.

The fixed sealing member110is elastically supported by a leaf spring or the like from a back surface, and is configured to be able to escape to a radial outer side when the fixed sealing member110is in contact with the tip shroud34. However, the fixed sealing member110is essentially immovable and does not move according to the operating state of the steam turbine1.

Meanwhile, as will be described below, the movable sealing member120has a large gap50with the tip shroud34when the steam turbine1is activated and deactivated, and moves in an arrow direction in the drawing to come into contact with the fixed sealing member110at the abutment surface114during rated operation of the steam turbine, so that the gap50is narrowed.

FIG.4Ais an enlarged view of a part A inFIG.3surrounded by a broken line and shows a first movable mechanism150A of a first sealing device100A which is the sealing device100according to the embodiment.

FIG.4Bis an enlarged view of the first movable mechanism150A when viewed from the radial outer side.

FIG.4Cis an exploded perspective view of the first movable mechanism150A.

FIG.5is a view showing only a first movable sealing member120A, which is the movable sealing member120of the first sealing device100A, of the first sealing device100A shown inFIG.4B.

FIG.6Ais a cross-sectional view taken along line B-B inFIGS.4A and9Aand shows a state when the steam turbine1is activated and deactivated.

FIG.6Bis a cross-sectional view taken along line C-C inFIGS.4A and9Aand shows a state when the steam turbine1is activated and deactivated.

FIG.7Ais a cross-sectional view taken along line B-B inFIGS.4A and9Aand shows a state during rated operation of the steam turbine1.

FIG.7Bis a cross-sectional view taken along line C-C inFIGS.4A and9Aand shows a state during rated operation of the steam turbine1.

FIG.8is a cross-sectional view taken along line D-D inFIG.4Aand shows a state during rated operation of the steam turbine1.

FIG.9Ais an enlarged view of the part A inFIG.3surrounded by a broken line and shows a second movable mechanism150B of a second sealing device100B which is a sealing device100according to another embodiment.

FIG.9Bis an enlarged view of the second movable mechanism150B when viewed from the radial outer side.

FIG.9Cis an exploded perspective view of the second movable mechanism150B.

FIG.10is a view showing only a second movable sealing member120B, which is the movable sealing member120of the second sealing device100B, of the second sealing device100B shown inFIG.9B.

FIG.11is a cross-sectional view taken along line E-E inFIG.9Aand shows a state during rated operation of the steam turbine1.

In the following description, when there is no particular need to distinguish between the first sealing device100A according to one embodiment and the second sealing device100B according to another embodiment, or when the first sealing device100A according to one embodiment and the second sealing device100B according to another embodiment are collectively described, the first sealing device100A and the second sealing device100B are simply referred to as the sealing device100.

Similarly, in the following description, when there is no particular need to distinguish between the first movable mechanism150A of the first sealing device100A according to one embodiment and the second movable mechanism150B of the second sealing device100B according to another embodiment, or when the first movable mechanism150A of the first sealing device100A according to one embodiment and the second movable mechanism150B of the second sealing device100B according to another embodiment are collectively described, the first movable mechanism150A and the second movable mechanism150B are simply referred to as the movable mechanism150.

In the following description, when there is no particular need to distinguish between the first movable sealing member120A of the first sealing device100A according to one embodiment and the second movable sealing member120B of the second sealing device100B according to another embodiment, or when the first movable sealing member120A of the first sealing device100A according to one embodiment and the second movable sealing member120B of the second sealing device100B according to another embodiment are collectively described, the first movable sealing member120A and the second movable sealing member120B are simply referred to as the movable sealing member120.

The sealing device100according to some embodiments includes the movable sealing member120that is disposed between the tip shroud34and the vane ring52disposed on the radial outer side of the tip shroud34and that is a sealing member for sealing the gap50between the tip shroud34and the vane ring52.

The sealing device100according to some embodiments includes a spring131as a biasing member that biases the movable sealing member120toward the radial outer side.

The sealing device100according to some embodiments includes a pressing plate133that presses the spring131from the radial outer side against a biasing force of the spring131.

The sealing device100according to some embodiments includes a support plate135that supports the spring131from the radial inner side.

The first sealing device100A according to one embodiment includes a first pressing plate133A that presses the spring131from the radial outer side against the biasing force of the spring131.

The second sealing device100B according to another embodiment includes a second pressing plate133B that presses the spring131from the radial outer side against the biasing force of the spring131.

In the following description, when there is no particular need to distinguish between the first pressing plate133A of the first sealing device100A according to one embodiment and the second pressing plate133B of the second sealing device100B according to another embodiment, or when the first pressing plate133A of the first sealing device100A according to one embodiment and the second pressing plate133B of the second sealing device100B according to another embodiment are collectively described, the first pressing plate133A and the second pressing plate133B are simply referred to as the pressing plate133.

In the first sealing device100A according to the embodiment, the first movable mechanism150A includes the spring131, the first pressing plate133A, and the support plate135.

In the second sealing device100B according to another embodiment, the second movable mechanism150B includes the spring131, the second pressing plate133B, and the support plate135.

In the sealing device100according to some embodiments, the pressing plate133is disposed on the radial outer side with respect to the movable sealing member120, and is fixed to the movable sealing member120by a plurality of bolts191as joining members. As shown inFIG.5, the movable sealing member120is formed with a female screw portion195that is screwed with a male screw of the bolt191in a base portion121to be described later.

In the sealing device100according to some embodiments, as shown inFIGS.6A,6B,7A,7B,8, and11, the movable sealing member120is held by the groove portion521formed in the vane ring52.

A seal fin122is provided on an inner peripheral side of the movable sealing member120, and the leakage of the steam S between the movable sealing member120and the tip shroud34is suppressed.

In the sealing device100according to some embodiments, as shown inFIGS.6B,7B,8, and11, the spring131, the pressing plate133, and the support plate135are provided inside the groove portion521of the vane ring52.

In some embodiments, the groove portion521of the vane ring52is formed in an inner peripheral portion52aof the vane ring52and extends in the circumferential direction. The groove portion521has an opening portion522that is open on the radial inner side.

In the vane ring52, a pair of protrusion portions523protruding in the axial direction are formed so that a dimension of the opening portion522in the axial direction is smaller than a dimension of a region on the radial outer side of the groove portion521in the axial direction with respect to the opening portion522.

In the sealing device100according to some embodiments, the support plate135abuts against the pair of protrusion portions523in the groove portion521from the radial outer side. Therefore, the movement of the support plate135toward the radial inner side in the groove portion521is restricted by the pair of protrusion portions523.

In the sealing device100according to some embodiments, the spring131biases the support plate135toward the radial inner side and biases the pressing plate133toward the radial outer side.

Therefore, the movable sealing member120in which the pressing plate133is fixed is biased by the spring131so that a gap between the seal fin122and the tip shroud34is widened.

The spring131may be, for example, a coil spring, and any biasing member such as a disc spring, a leaf spring, or a metal bellows may be used instead of the coil spring.

When the steam turbine1is activated and deactivated, the steam S is not introduced into the groove portion521, or even if the steam S is introduced, the pressure in the groove portion521is relatively low. Therefore, as shown inFIGS.6A and6B, in the sealing device100according to some embodiments, the movable sealing member120moves to the radial outer side by means of the biasing force of the spring131. Accordingly, the gap between the seal fin122and the tip shroud34is widened.

(During Rated Operation of Steam Turbine1)

During rated operation of the steam turbine1, the relatively high-pressure steam S is introduced into the groove portion521, and the pressure in the groove portion521becomes relatively high. Therefore, as shown inFIGS.7A and7B, in the sealing device100according to some embodiments, the movable sealing member120moves to the radial outer side against the biasing force of the spring131by means of the pressure of the steam S in the groove portion521. Accordingly, the gap between the seal fin122and the tip shroud34is narrowed.

(Reliability of Operation of Movable Sealing Member120)

In the sealing device upper-half portion100U of the sealing device100according to some embodiments, the movable sealing member120needs to be moved vertically upward by the biasing force of the spring131against a self-weight of the movable sealing member120. Therefore, in order to reliably secure the gap between the seal fin122and the tip shroud34when the steam turbine1is activated and deactivated, the biasing force of the spring131has to be sufficiently large. However, when the biasing force of the spring131is excessively large, it becomes difficult to displace the movable sealing member120to the radial inner side during the rated operation of the steam turbine1.

In the sealing device100according to some embodiments, the dimension of the movable sealing member120in the radial direction is larger than the dimension of the gland seal, the stator vane tip seal, the dummy ring seal, or the like in the radial direction. Since the self-weight of the sealing member increases as the dimension of the movable sealing member120in the radial direction increases, the biasing force of the spring131has to be increased. Therefore, as the dimension of the movable sealing member120in the radial direction increases, it tends to become difficult to set the biasing force of the spring131. Therefore, in the sealing device100according to some embodiments, it is difficult to set the biasing force of the spring131as compared with the biasing force of the gland seal, the stator vane tip seal, or the dummy ring seal.

In addition, in the sealing device upper-half portion100U of the sealing device100according to some embodiments, the movable sealing member120needs to be displaced to the radial inner side against the self-weight of the movable sealing member120and the biasing force of the spring131during the rated operation of the steam turbine1. Therefore, in order to reliably displace the movable sealing member120to the radial inner side during the rated operation of the steam turbine1, the biasing force of the spring131has to be relatively small. However, when the biasing force of the spring131is excessively small, it becomes difficult to secure the gap between the seal fin122and the tip shroud34when the steam turbine1is activated and deactivated. Therefore, as the dimension of the movable sealing member120in the radial direction increases, it tends to become difficult to set the biasing force of the spring131.

Therefore, in the sealing device100according to some embodiments, the movable sealing member120is configured as follows so that the self-weight of the movable sealing member120is suppressed while the rigidity of the movable sealing member120is secured.

That is, in the sealing device100according to some embodiments, for example, as shown inFIGS.4A,4B,4C,5,6A,6B,7A,7B,8,9A,9B,9C,10, and11, the movable sealing member120has the base portion121extending in the circumferential direction.

In the sealing device100according to some embodiments, for example, as shown inFIGS.4A,4B,4C,5,6A,6B,7A,7B,8,9A,9B,9C,10, and11, the movable sealing member120includes a rib123that extends in the circumferential direction and that protrudes from the base portion121toward the radial outer side.

In the sealing device100according to some embodiments, for example, as shown inFIGS.4A,4C,6A,6B,7A,7B,8,9A,9C, and11, the movable sealing member120includes the seal fin122that extends in the circumferential direction and that protrudes from the base portion121toward the radial inner side.

In the sealing device100according to some embodiments, for example, as shown inFIGS.4C,5,9C, and10, the rib123includes a notch portion125in which the spring131is disposed between one end and the other end of the rib123in the circumferential direction.

In the sealing device100according to some embodiments, the ribs123are provided on the movable sealing member120, whereby the self-weight of the movable sealing member120can be suppressed while the rigidity of the movable sealing member120is secured. Accordingly, when the steam turbine1is activated and deactivated, the gap between the tip shroud34and the seal fin122, which is the seal gap between the tip shroud34as the rotating member and the movable sealing member120, is easily secured, and during the rated operation of the steam turbine1, the amount of leakage of the steam S, which is the working fluid, can be reduced.

The steam turbine1according to some embodiments includes the tip shroud34as a rotating member, the vane ring52as a stationary member, and the sealing device100according to some embodiments.

Accordingly, when the steam turbine1is activated and deactivated, the gap between the tip shroud34and the seal fin122, which is the seal gap between the tip shroud34as the rotating member and the movable sealing member120, is easily secured, and during the rated operation of the steam turbine1, the amount of leakage of the steam S, which is the working fluid, can be reduced.

In the sealing device100according to some embodiments, a distance L1 from a radial inner surface121aof the base portion121to a radial outer end surface123aof the rib123may be three times or more a distance L2 from the radial inner surface121aof the base portion121to a radial outer surface121bof the base portion121.

Accordingly, a region R where the portion constituting the movable sealing member120is not present on both sides in the axial direction with the rib123interposed therebetween can be provided. Therefore, the self-weight of the movable sealing member120can be reduced by the amount corresponding to this region. According to the sealing device100according to some embodiments, with respect to the thickness (distance L2) of the base portion121in the radial direction, the length of the rib123in the radial direction ((distance L1)−(distance L2)) is relatively large. Therefore, the region R is relatively large, and the self-weight of the movable sealing member120is relatively small. Accordingly, when the steam turbine1is activated and deactivated, the gap between the tip shroud34and the seal fin122, which is the seal gap between the tip shroud34as the rotating member and the movable sealing member120, is easily secured, and during the rated operation of the steam turbine1, the amount of leakage of the steam S, which is the working fluid, can be reduced.

In the sealing device100according to some embodiments, the base portion121may include an insertion portion124inserted into the opening portion522in the groove portion521extending in the circumferential direction, the groove portion521being formed in the inner peripheral portion52aof the vane ring52serving as the stationary member. A dimension L3 of the rib123in the axial direction may be 0.3 times or less a dimension L4 of the insertion portion124in the axial direction.

Accordingly, a region R where the portion constituting the movable sealing member120is not present on both sides in the axial direction with the rib123interposed therebetween can be provided. Therefore, the self-weight of the movable sealing member120can be reduced by the amount of the region R. According to the sealing device100according to some embodiments, the thickness (dimension L3) of the rib123with respect to the dimension in the axial direction (dimension L4) of the base portion121is relatively small. Therefore, the region R is relatively large, and the self-weight of the movable sealing member120is relatively small.

Accordingly, when the steam turbine1is activated and deactivated, the gap between the tip shroud34and the seal fin122, which is the seal gap between the tip shroud34as the rotating member and the movable sealing member120, is easily secured, and during the rated operation of the steam turbine1, the amount of leakage of the steam S, which is the working fluid, can be reduced.

In the sealing device100according to some embodiments, in the region where the notch portion125is present, the height of the rib123(dimension in the radial direction) is lower than that in the other region, or the rib123is not present. Therefore, the base portion121at the circumferential position where the notch portion125is present is easily deformed to be bent along a virtual plane extending in the radial direction as compared with other regions where the notch portion125is not present.

Therefore, the sealing device100according to some embodiments may include a restricting member160that is a member different from the movable sealing member120and that restricts deformation of the base portion121at the circumferential position where the notch portion125is present.

Accordingly, the deformation of the base portion121at the circumferential position where the notch portion125is present is restricted by the restricting member160. Therefore, the rigidity of the movable sealing member120can be secured even when the notch portion125is provided.

In the sealing device100according to some embodiments, the restricting member160may be the pressing plate133that presses the spring131from the radial outer side against the biasing force of the spring131as the biasing member.

Accordingly, the restricting member160may not be newly provided as a member separate from the pressing plate133, and the rigidity of the movable sealing member120can be secured by the pressing plate133.

In the sealing device100according to some embodiments, the restricting member160may be fixed to the base portion on one side in the circumferential direction and to the base portion121on the other side in the circumferential direction with the notch portion125interposed therebetween by the joining member. In the sealing device100according to some embodiments, for example, as shown inFIGS.4A,4B,4C,9A,9B, and9C, the restricting members160are fixed to the base portion121by the bolts191at a total of four locations, that is, each of one side and the other side in the circumferential direction with the notch portion125interposed therebetween and each of one side and the other side in the axial direction with the rib123interposed therebetween. In addition, in the sealing device100according to some embodiments, for example, as shown inFIGS.4A,4B,4C,9A,9B, and9C, the restricting member160is fixed to the base portion121by the bolt191at one location at the circumferential position where the notch portion125is provided.

Accordingly, the restricting member160can be stably fixed to the movable sealing member120.

In the sealing device100according to some embodiments, the restricting member160may extend from one side to the other side in the axial direction with the rib123interposed therebetween.

In the sealing device100according to some embodiments, the restricting members160are present on one side and the other side in the axial direction with the rib123interposed therebetween, whereby the reinforcement can be performed by being balanced in the axial direction with a relatively simple configuration. In addition, in the sealing device100according to some embodiments, the rigidity of the movable sealing member120in the circumferential direction can also be stably reinforced.

In the sealing device100according to some embodiments, for example, as well shown inFIGS.4C and9C, the rib123may include a first rib141on one side and a second rib142on the other side in the circumferential direction with the notch portion125interposed therebetween. The restricting member160may be joined to the first rib141and the second rib142in a form to be described later.

Accordingly, the restricting member160restricts the relative movement between the first rib141and the second rib142, so that the deformation of the base portion121at the circumferential position where the notch portion125is present can be suppressed. Accordingly, the rigidity of the movable sealing member120can be secured even when the notch portion125is provided.

(Case of First Sealing Device100A According to One Embodiment)

In the first sealing device100A according to the embodiment, for example, as shown inFIGS.4A,4B,4C,5, and8, the first rib141may be provided with a first through-hole143penetrating the first rib141in the axial direction. The second rib142may be provided with a second through-hole144penetrating the second rib142in the axial direction.

In the first sealing device100A according to one embodiment, for example, as shown inFIGS.4A,4B,4C, and8, the restricting member160may be provided with third through-holes163penetrating the restricting member160in the axial direction and fourth through-holes164penetrating the restricting member in the axial direction at a position separated from the third through-holes163in the circumferential direction.

The first sealing device100A according to one embodiment may include, for example, at least two joining pins193that join the restricting member160and the first rib141and the second rib142to each other, as shown inFIGS.4A and4B. At least one of the joining pins193may be inserted into the first through-hole143and the third through-holes163, and at least another one of the joining pins193may be inserted into the second through-hole144and the fourth through-holes164.

In addition, in the exploded perspective view ofFIG.4C, the description of the joining pin193is omitted.

In the first sealing device100A according to the embodiment, the rigidity of the movable sealing member120can be relatively easily secured by a relatively simple configuration in which the restricting member160and the first rib141and the second rib142are joined by the joining pin193.

In the first sealing device100A according to the embodiment, the third through-holes163may be provided on one side and the other side in the axial direction with the first rib141interposed therebetween, and the fourth through-holes164may be provided on one side and the other side in the axial direction with the second rib142interposed therebetween, in the restricting member160. That is, the restricting member160may be present on one side and the other side in the axial direction with the first rib141and the second rib142interposed therebetween, and may be connected to the one side and the other side in the axial direction with the first rib141and the second rib142interposed therebetween via the joining pin193.

In the first sealing device100A according to the embodiment, the restricting members160are present on one side and the other side in the axial direction with the first rib141and the second rib142interposed therebetween, whereby the reinforcement can be performed by being balanced in the axial direction with a relatively simple configuration. In addition, according to the first sealing device100A according to the embodiment, the rigidity of the movable sealing member120in the circumferential direction can also be stably reinforced.

(Case of Second Sealing Device100B According to Other Embodiment)

In the second sealing device100B according to another embodiment, for example, as shown inFIGS.9A,9C,10, and11, the first rib141may be formed with a first recessed portion145recessed toward the radial inner side. In the second sealing device100B according to another embodiment, for example, as shown inFIGS.9A,9C,10, and11, the second rib142may be formed with a second recessed portion146recessed toward the radial inner side. In the second sealing device100B according to another embodiment, for example, as shown inFIGS.9A,9C, and11, the restricting member160may have a first protrusion portion165fitted to the first recessed portion145and a second protrusion portion166fitted to the second recessed portion146.

Accordingly, the rigidity of the movable sealing member120can be relatively easily secured with a relatively simple configuration in which the restricting member160and the first rib141and the second rib142are joined to each other by fitting the first protrusion portion165and the first recessed portion145to each other and fitting the second protrusion portion166and the second recessed portion146to each other.

The present disclosure is not limited to the above-described embodiments, and includes a modification of the above-described embodiments and an appropriate combination of the embodiments.

For example, in the above description, a case where the sealing device100according to some embodiments is applied to the steam turbine1as an example of the rotating machine has been described. However, the sealing device100according to some embodiments may be applied to other rotating machines such as a gas turbine.

The contents described in each embodiment are understood as follows, for example.

(1) A sealing device100according to at least one embodiment of the present disclosure includes a movable sealing member120that is disposed between a tip shroud34serving as a rotating member of a steam turbine1as a rotating machine and a vane ring52serving as a stationary member disposed on a radial outer side of the rotating member with respect to the tip shroud34serving as the rotating member, and that is a sealing member sealing between the rotating member (tip shroud34) and the stationary member (vane ring52); and a spring131serving as a biasing member that biases the sealing member (movable sealing member120) toward the radial outer side. The sealing member (movable sealing member120) includes a base portion121extending in a circumferential direction of the rotating member, a rib123extending in the circumferential direction and protruding from the base portion121toward the radial outer side, and a seal fin122extending in the circumferential direction and protruding from the base portion121toward a radial inner side of the rotating member. The rib123includes a notch portion125in which a biasing member (spring131) is disposed between one end and the other end of the rib123in the circumferential direction.

According to the configuration of (1), the rib123described above is provided on the sealing member (movable sealing member120). In this manner, a self-weight of the sealing member (movable sealing member120) can be suppressed while the rigidity of the sealing member (movable sealing member120) is secured. As a result, a seal gap between the rotating member (the tip shroud34) and the sealing member (the movable sealing member120) is easily secured when the rotating machine (the steam turbine1) is activated and deactivated, and the amount of leakage of steam S as the working fluid can be reduced during the operation of the rotating machine (the steam turbine1).

(2) In some embodiments, in the configuration of (1) described above, a distance L1 from a radial inner surface121aof the base portion121to a radial outer end surface123aof the rib123may be three times or more a distance L2 from the radial inner surface121aof the base portion121to a radial outer surface121bof the base portion121.

According to the configuration of (2) described above, a region R where the portion that forms the sealing member (movable sealing member120) is not present on both sides in an axial direction with the rib123interposed therebetween can be provided. Therefore, the self-weight of the sealing member (movable sealing member120) can be reduced by the amount of the region R. According to the configuration of (2) described above, with respect to the thickness (distance L2) of the base portion121in a radial direction, the length of the rib123in the radial direction ((distance L1)−(distance L2)) is relatively large. Therefore, the region R is relatively large, and the self-weight of the sealing member (movable sealing member120) is relatively small. As a result, the seal gap between the rotating member (tip shroud34) and the sealing member (movable sealing member120) is easily secured when the rotating machine (the steam turbine1) is activated and deactivated, and amount of leakage of the working fluid (steam S) can be reduced during the operation of the rotating machine (the steam turbine1).

(3) In some embodiments, in the configuration of (1) or (2) described above, the base portion121may include an insertion portion124inserted into an opening portion522in a groove portion521extending in the circumferential direction, the groove portion521being formed in an inner peripheral portion52aof the stationary member (vane ring52). A dimension L3 of the rib123of the rotating member in the axial direction may be 0.3 times or less a dimension L4 of the insertion portion124in the axial direction.

According to the configuration of (3) described above, a region R where the portion that forms the sealing member (movable sealing member120) is not present on both sides in the axial direction with the rib123interposed therebetween can be provided. Therefore, the self-weight of the sealing member (movable sealing member120) can be reduced by the amount of the region R. According to the configuration of (3) described above, the thickness (dimension L3) of the rib123with respect to the dimension in the axial direction (dimension L4) of the base portion121is relatively small. Therefore, the region R is relatively large, and the self-weight of the sealing member (movable sealing member120) is relatively small. As a result, the seal gap between the rotating member (tip shroud34) and the sealing member (movable sealing member120) is easily secured when the rotating machine (the steam turbine1) is activated and deactivated, and amount of leakage of the working fluid (steam S) can be reduced during the operation of the rotating machine (the steam turbine1).

(4) In some embodiments, in any one of the configurations of (1) to (3) described above, a restricting member160that is a member different from the sealing member (movable sealing member120) and that restricts deformation of the base portion121at a circumferential position where the notch portion125is present may be included.

In the region where the notch portion125is present, the height of the rib123is lower than that in other regions, or the rib123is not present. Therefore, the base portion121at the circumferential position where the notch portion125is present is easily deformed to be bent along a virtual plane extending in the radial direction as compared with other regions where the notch portion125is not present.

According to the configuration of (4) described above, the deformation of the base portion121at the circumferential position where the notch portion125is present is restricted by the restricting member160. Therefore, the rigidity of the sealing member (movable sealing member120) can be secured even when the notch portion125is provided.

(5) In some embodiments, in the configuration of (4) described above, the rib123may include a first rib141on one side and a second rib142on the other side in the circumferential direction with the notch portion125interposed therebetween. The restricting member160may be joined to the first rib141and the second rib142.

According to the configuration of (5), the restricting member160restricts the relative movement between the first rib141and the second rib142, so that the deformation of the base portion121at the circumferential position where the notch portion125is present can be suppressed. Accordingly, the rigidity of the sealing member (movable sealing member120) can be secured even when the notch portion125is provided.

(6) In some embodiments, in the configuration of (5) described above, the first rib141may be provided with a first through-hole143penetrating the first rib141in an axial direction of the rotating member. The second rib142may be provided with a second through-hole144penetrating the second rib142in the axial direction. The restricting member160may be provided with third through-holes163penetrating the restricting member160in the axial direction and fourth through-holes164penetrating the restricting member160in the axial direction at a position separated from the third through-holes163in the circumferential direction. The sealing device100may include at least two joining pins193that join the restricting member160and the first rib141and the second rib142to each other. At least one of the joining pins193may be inserted into the first through-hole143and the third through-holes163, and at least another one of the joining pins193may be inserted into the second through-hole144and the fourth through-holes164.

According to the configuration of (6), the rigidity of the sealing member (movable sealing member120) can be relatively easily secured by a relatively simple configuration in which the restricting member160and the first rib141and the second rib142are joined by the joining pin193.

(7) In some embodiments, in the configuration of (6) described above, the third through-holes163may be provided on one side and the other side in the axial direction with the first rib141interposed therebetween, and the fourth through-holes164may be provided on one side and the other side in the axial direction with the second rib142interposed therebetween, in the restricting member160.

According to the configuration of (7) described above, the restricting members160are present on one side and the other side in the axial direction with the first rib141and the second rib142interposed therebetween, whereby the reinforcement can be performed by being balanced in the axial direction with a relatively simple configuration. In addition, according to the configuration of (7) described above, the rigidity of the sealing member (movable sealing member120) in the circumferential direction can also be stably reinforced.

(8) In some embodiments, in the configuration of (5) described above, the first rib141may be formed with a first recessed portion145recessed toward the radial inner side. The second rib142may be formed with a second recessed portion146recessed toward the radial inner side. The restricting member160may have a first protrusion portion165that is fitted to the first recessed portion145and a second protrusion portion166that is fitted to the second recessed portion146.

According to the configuration of (8) described above, the rigidity of the sealing member (movable sealing member120) can be relatively easily secured with a relatively simple configuration in which the restricting member160and the first rib141and the second rib142are joined to each other by fitting the first protrusion portion165and the first recessed portion145to each other and fitting the second protrusion portion166and the second recessed portion146to each other.

(9) In some embodiments, in any one of the configurations (4) to (8) described above, the restricting member160may be fixed to the base portion on one side in the circumferential direction and to the base portion121on the other side in the circumferential direction with the notch portion125interposed therebetween by the joining member (bolt191).

According to the configuration of (9) described above, the restricting member160can be stably fixed to the sealing member (movable sealing member120).

(10) In some embodiments, in any one of the configurations (4) to (9) described above, the restricting member160may extend from one side to the other side in an axial direction of the rotating member with the rib123interposed therebetween.

According to the configuration (10) described above, the restricting members160are present on one side and the other side in the axial direction with the rib123interposed therebetween, whereby the reinforcement can be performed by being balanced in the axial direction with a relatively simple configuration. In addition, according to the configuration of (10) described above, the rigidity of the sealing member (movable sealing member120) in the circumferential direction can also be stably reinforced.

(11) In some embodiments, in any one of the configurations (4) to (10) described above, the restricting member160may be a pressing plate133that presses the biasing member (spring131) from the radial outer side against a biasing force of the biasing member (spring131).

According to the configuration of (11) described above, the restricting member160may not be newly provided as a member separate from the pressing plate133, and the rigidity of the movable sealing member120can be secured by the pressing plate133.

(12) A rotating machine according to at least one embodiment of the present disclosure includes the tip shroud34as the rotating member, the vane ring52as the stationary member, and the sealing device100having any one of the configurations of (1) to (11).

According to the configuration of (12) described above, the seal gap between the rotating member (tip shroud34) and the sealing member (movable sealing member120) is easily secured when the rotating machine (the steam turbine1) is activated and deactivated, and the amount of leakage of the working fluid (steam S) can be reduced during the operation of the rotating machine (the steam turbine1).

REFERENCE SIGNS LIST