JP2014167263A - Damping member for rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the damping performance while securing a seal function and inhibit vibrations of a rotary machine member.SOLUTION: A damping member for a rotary machine includes: a first plate part 11 which contacts with a platform 4A of one gas turbine rotor blade 1A; a second plate part 12 which contacts with a platform 4A of the other gas turbine rotor blade 1B; and a viscoelastic damper 13 disposed between the first plate part 11 and the second plate part 12. A recessed groove 41 is provided on a side surface 4a of one gas turbine 1A, and a part of the viscoelastic damper 10 forms a protruding shape bent along the recessed groove 41.

Description

  The present invention relates to a damping member for a rotary machine used in, for example, a gas turbine.

  Conventionally, in a gas turbine, a plurality of disks are arranged in the axial direction of a rotating shaft, and a large number of rotor blades are implanted adjacent to the outer periphery of these disks in the circumferential direction. Between the moving blades adjacent to each other in the axial direction, a stationary blade provided in a casing covering the outside of the moving blade is disposed. When a high-temperature combustion gas flows between the moving blades and the stationary blades, the rotating shaft is driven to rotate together with the moving blades, and for example, the compressor and the generator are driven.

  And if the rotating shaft of a gas turbine is rotationally driven, the disc provided in the rotating shaft will be rotationally driven. At this time, the plurality of moving blades provided on the disk move between the plurality of stationary blades provided on the casing provided outside the rotating shaft. When hot combustion gas flows between these blades, a vortex is generated at the rear end of each blade. Due to this vortex, a force is applied to each blade toward the front and rear sides of the gas turbine, or a force is applied toward the adjacent blade, causing vibrations in each blade. Then, the frequency of the stationary blade disposed in the casing matches the natural frequency of the moving blade (hereinafter simply referred to as the natural frequency) and resonates to increase the vibration of each blade, resulting in high cycle fatigue (HCF). Could occur.

Therefore, in such a gas turbine, a structure is known in which seal pins are interposed between adjacent blades for the purpose of reducing vibrations of the blades and preventing leakage of cooling air (for example, patents). Reference 1).
Patent Document 1 discloses a seal pin that prevents cooling air on the blade root side from leaking to the blade side in a gap in a shank between gas turbine rotor blades attached adjacently along the circumferential direction of the rotating shaft. On the other hand, a configuration is described in which an arc-shaped recess is formed in the shank, and the shank is used as a spring system, the wing part, the platform, the shank, and the blade root as a mass system to suppress vibration of the gas turbine blade. ing.

JP 2005-233141 A

However, the conventional gas turbine has the following problems.
That is, in Patent Document 1, there is a problem in that the natural frequency varies depending on the position and movement of the seal pin during actual operation of the gas turbine, and the gas turbine rotor blade vibrates, resulting in fatigue failure.
For this reason, it is necessary to set a large design margin for vibration strength, and the degree of freedom in designing the turbine is reduced, so there is room for improvement in that respect.

  The present invention has been made in view of the above-described problems, and provides a damping member for a rotating machine that can improve damping performance and can suppress vibration of the rotating machine member while ensuring a sealing function. The purpose is to provide.

  In order to achieve the above object, the damping member for a rotary machine according to the present invention includes a damping member body disposed between a pair of rotary machine members that vibrate relatively, and the damping member body includes one of the rotating machines. A first plate that contacts the member, a second plate that contacts the other rotating machine member, and a viscoelastic member interposed between the first and second plates. It is characterized by.

  In the present invention, when the resonance is caused by the rotational motion of the rotary machine member and the distance between the pair of rotary machine members varies due to the resonance, the damping member main body includes the first plate portion and the second plate portion. Friction damping occurs with the rotating machine member. In addition, since a viscoelastic member having rigidity lower than these is interposed between the first plate portion and the second plate portion, the viscoelastic member undergoes shear deformation due to frictional force, and the viscoelastic member itself Since internal damping occurs, the vibration response level of the rotary machine member can be reduced. That is, since internal damping occurs with the deformation of the damping member body itself, kinetic energy is converted into internal thermal energy.

In the rotating machine damping member of the present invention, even when centrifugal force acts on the rotating machine member or the rotating machine member is deformed, the damping member main body maintains a certain shape, Variations in dynamic characteristics can be reduced.
As described above, the present invention can effectively exhibit a damping effect, and therefore has an advantage that it is not necessary to provide a large design margin for the vibration strength of the rotary machine member.

  Furthermore, even if the distance between the pair of rotating machine members varies, the viscoelastic member elastically deforms to follow the variation in the distance, and the first plate unit and the second plate unit are used for the rotating machine. Since the contact state with the member can be maintained, a sealing function can be secured.

  In the rotating machine damping member according to the present invention, one of the pair of rotating machine members is provided with a concave groove on a side surface on the damping member main body side. It is preferable that the portion has a protruding shape bent along the concave groove.

  In the present invention, the projecting portion of the damping member main body is provided to engage with the concave groove of one rotary machine member, and the damping member main body is at least relative to the rotary machine member on the side where the concave groove is formed. Since it is restrained, it is possible to prevent the displacement of the position of the attenuation member main body.

  According to the damping member for a rotary machine of the present invention, it is possible to improve the damping performance while ensuring the sealing function, and to suppress the vibration of the rotating machine member.

It is the perspective view which looked at the gas turbine rotor blade by the 1st Embodiment of this invention from the front edge side. It is the perspective view which looked at the gas turbine rotor blade shown in FIG. 1 from the trailing edge side. It is a side view showing the state where the gas turbine rotor blade was adjacent. It is an enlarged view of the viscoelastic damper shown in FIG. It is a side view which shows schematic structure of the gas turbine rotor blade by 2nd Embodiment. FIG. 6 is an enlarged perspective view of the integral shroud of FIG. 5, showing a state in which the viscoelastic damper is removed. It is the figure which looked at a pair of adjacent integral shrouds from the outside in the radial direction. It is the sectional view on the AA line shown in FIG.

  Hereinafter, a damping member for a rotary machine according to an embodiment of the present invention will be described based on the drawings. This embodiment shows one aspect of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention.

(First embodiment)
As shown in FIG. 1, the gas turbine to which the gas turbine rotor blade 1 (rotary machine member) of the present embodiment is applied is used in a power plant or the like. For example, such a gas turbine includes a compressor, a combustor, and a turbine. Compressed air compressed by the compressor is combusted with fuel in the combustor, and combustion gas is introduced into the turbine to drive the turbine. . The compressor is operated by the power of the turbine, and power is generated by the generator.

  As shown in FIGS. 1 and 2, the gas turbine rotor blade 1 is provided in multiple stages along the axial direction (the rotational axis direction of the turbine) on the rotating shaft side of the turbine. The gas turbine rotor blade 1 has a Christmas tree type blade root 2 held on the rotating shaft side. Further, the gas turbine rotor blade 1 includes a blade portion 5 that is exposed to high-temperature gas, a platform 4 that supports the blade portion 5, and a shank 3 that connects the platform 4 and the blade root 2. The blade root 2 is embedded in a disk (not shown) and supports the gas turbine blade 1.

  As shown in FIG. 3, one of the adjacent gas turbine rotor blades 1 with a gap S therebetween is defined as a first gas turbine rotor blade 1A, and the other is defined as a second gas turbine rotor blade 1B. On one side surface 4a (one side surface in the circumferential direction of the rotating shaft) of each of the platforms 4A and 4B of the gas turbine rotor blades 1A and 1B, a concave groove 41 for accommodating a part of the viscoelastic damper 10 described later is provided. ing.

  The concave grooves 41 prevent high-temperature combustion gas flowing on the blade portion 5 side of the gas turbine rotor blade 1 from flowing into the blade root 2 side, and pass through the gas turbine rotor blade 1 to pass through these gas turbines. Cooling air that is a cooling medium for cooling the moving blade 1 is prevented from leaking from the blade root 2 side to the blade portion 5 side.

The concave groove 41 of the first gas turbine rotor blade 1A has a pair of first walls 41a extending from the blade portion 5A side toward the blade root 2 side in the side view and extending into the platform 4A, and the first wall 41a. The second wall 41b is continuous and extends downward in parallel with the side surface 4a of the platform 4A (see FIG. 4).
However, even when the viscoelastic damper 10 disposed in the concave groove 41 is disposed on the blade root 2 side, the viscoelastic damper 10 has the walls 41a and 41b in the concave groove 41 and the adjacent second gas. It contacts the side surface 4b of the platform 4B of the turbine rotor blade 1B. Therefore, the adjacent first gas turbine rotor blade 1A and the second gas turbine rotor blade 1B are not in direct contact with each other so that a gap S is formed, and the vibration of the first gas turbine rotor blade 1A passes through the viscoelastic damper 10. Propagating to the adjacent second gas turbine rotor blade 1B, or conversely, vibration of the second gas turbine 1B propagates to the first gas turbine rotor blade 1A via the viscoelastic damper 10.

  When the rotating shaft of the turbine rotates and the first gas turbine blade 1A and the second gas turbine blade 1B are driven, centrifugal force, that is, the blade portion 5A side is applied to the viscoelastic damper 10 provided in the groove 41. At this time, the first gas turbine rotor blade 1A and the second gas turbine rotor blade 1B vibrate.

Specifically, the first gas turbine rotor blade 1A and the second gas turbine rotor blade 1B vibrate in a direction away from each other, or vibrate in a contact direction.
As shown in FIG. 4, when the adjacent first gas turbine blade 1 </ b> A and second gas turbine blade 1 </ b> B vibrate away from each other, the viscoelastic damper 10 is deformed. At this time, the position of the end portion of the viscoelastic damper 10 is shifted in the direction toward the inner side in the height direction H (the direction of arrow E2 in FIG. 4), and friction occurs between the moving blades 1A and 1B and the viscoelastic damper 10. Attenuation works. Furthermore, since the viscoelastic damper 10 itself is deformed, internal damping is also obtained.

  Further, when the adjacent first gas turbine blade 1A and second gas turbine blade 1B vibrate in the approaching direction, the viscoelastic damper 10 is deformed. At this time, the position of the end portion of the viscoelastic damper 10 is shifted in the direction toward the outer side in the height direction H (the direction of arrow E1 in FIG. 4), and friction occurs between the moving blades 1A and 1B and the viscoelastic damper 10. Attenuation works. Furthermore, since the viscoelastic damper 10 itself is deformed, internal damping is also obtained. Therefore, the first gas turbine rotor blade 1A is supported by a disk (not shown) by the blade root 2, and is also supported by the viscoelastic damper 10 interposed between the adjacent second gas turbine rotor blade 1B.

  As shown in FIGS. 2 and 4, a viscoelastic damper 10 (attenuating member main body) disposed between a pair of gas turbine blades 1A and 1B that vibrate relatively contacts one first gas turbine blade 1A. A first plate portion 11 that is in contact, a second plate portion 12 that is in contact with the other second gas turbine blade 1B, and a viscoelastic member 13 that is interposed between the first plate portion 11 and the second plate portion 12; It is equipped with.

  The viscoelastic damper 10 includes a first contact portion 10a located at the center in the height direction H, a pair of inclined portions 10b extending from both ends of the first contact portion 10a, and a first contact of the inclined portion 10b. The cross section has a hat shape with a pair of second contact portions 10c at the tip extending in parallel with the first contact portion 10a on the opposite side of the contact portion 10a. The first contact portion 10a and the second contact portion 10c are formed along the side surfaces 4a and 4b of the platform 4 that form the gap S.

  The viscoelastic damper 10 is positioned by engaging a projecting shape portion T formed by the first contact portion 10a and the pair of inclined portions 10b into the groove 41 of the platform 4A of the first gas turbine rotor blade 1A. Thus, the pair of second abutting portions 10c are interposed in a state of being sandwiched by the gap S between the platform 4A of the first gas turbine rotor blade 1A and the platform 4B of the second gas turbine rotor blade 1B.

  The first plate portion 11 and the second plate portion 12 are formed by bending a metal flat plate-like member into the hat shape along the height direction (indicated by an arrow H in FIGS. 2 and 4). It is a thing.

  The viscoelastic member 13 is made of a soft material having a lower rigidity than the members of the first plate portion 11 and the second plate portion 12 such as fluorine rubber, silicon gel, and graphite fiber. The viscoelastic member 13 is not limited to being fixed, and may not be fixed.

Next, the operation of the gas turbine rotor blade 1 having the above-described configuration will be specifically described based on the drawings.
As shown in FIG. 1, in this embodiment, when the rotating shaft of the turbine rotates and the first gas turbine rotor blade 1A and the second gas turbine rotor blade 1B are driven, they are engaged with the concave groove 41. A centrifugal force, that is, a force toward the wing portion 5A is applied to the viscoelastic damper 10, and the viscoelastic damper 10 sticks to the wing portion 5A side in the concave groove 41. At this time, the first gas turbine blade 1A and the second gas turbine blade 1B vibrate. Specifically, the first gas turbine rotor blade 1 </ b> A and the second gas turbine rotor blade 1 </ b> B vibrate in a direction away from each other or vibrate in a contact direction.

  At this time, when the distance between the pair of gas turbine rotor blades 1A and 1B fluctuates due to the rotational motion of the gas turbine, the first plate portion 11 and the second plate are provided in the viscoelastic damper 10. Friction damping occurs between the section 12 and the gas turbine rotor blades 1A, 1B.

  In addition to this, since the viscoelastic member 13 having rigidity lower than these is interposed between the first plate portion 11 and the second plate portion 12, the viscoelastic member 13 is shear-deformed by a frictional force, Since internal damping occurs in the viscoelastic member 13 itself, an effect that the vibration response level of the gas turbine rotor blade 1 can be reduced is obtained. That is, since internal damping occurs with deformation of the viscoelastic damper 10 itself, kinetic energy is converted into internal thermal energy.

In the turbine of the present embodiment, the viscoelastic damper 10 maintains a constant shape even when centrifugal force acts on the gas turbine rotor blade 1 or the gas turbine rotor blade 1 is deformed. Therefore, variation in dynamic characteristics can be reduced.
Thus, in this embodiment, since the damping effect can be effectively exhibited, there is an advantage that it is not necessary to take a large design margin for the vibration strength of the gas turbine rotor blade 1.

  Furthermore, even if the distance between the pair of gas turbine rotor blades 1A and 1B varies, the viscoelastic member 13 of the viscoelastic damper 10 elastically deforms to follow the variation in the distance, and the first plate portion 11 and the second plate portion 12 and the gas turbine rotor blades 1A and 1B can be kept in contact with each other, and therefore a sealing function can be secured.

  Further, the protruding portion T of the viscoelastic damper 10 is engaged with the concave groove 41 on one side surface 4 a of the platform 4 of the gas turbine rotor blade 1, and the viscoelastic damper 10 is restrained with respect to the gas turbine rotor blade 1. Therefore, the position shift of the viscoelastic damper 10 can be prevented.

  In the damping member for a rotating machine according to the above-described embodiment, the damping performance can be improved while ensuring the sealing function, and the vibration of the gas turbine rotor blades 1A and 1B can be suppressed.

  Next, another embodiment of the damping member for a rotary machine according to the present invention will be described with reference to the accompanying drawings. The same reference numerals are used for the same or similar members and parts as those in the first embodiment. A description will be omitted, and a configuration different from that of the first embodiment will be described.

(Second Embodiment)
Reference numerals 6 (6A, 6B) in FIGS. 5 to 7 denote integral shrouds (rotary machine members) provided at the blade tips 5a of the blade portions 5 (5A, 5B). The damping member for a rotary machine according to the second embodiment has viscoelastic dampers on contact surfaces (side surfaces 6a and 6b) between the integral shrouds 6A and 6B provided at the blade tips 5a of the adjacent blade portions 5A and 5B. 30 (attenuation member main body) is provided. That is, the viscoelastic damper 30 is sandwiched between the pair of integral shrouds 6A and 6B. The integral shrouds 6A and 6B are subjected to centrifugal force together with the gas turbine rotor blade 1 by the rotational motion of the gas turbine.

  As shown in FIGS. 6 and 8, a viscoelastic damper 30 is provided on one side surface 6a (one side surface in the circumferential direction of the rotating shaft) of one of the integral shrouds 6A adjacent with a gap S (see FIG. 7). A recessed groove 61 is provided to accommodate the. The concave groove 61 has the same shape as the concave groove 41 provided in the platform 4 of the first embodiment described above, although the size is different, and detailed description thereof is omitted. The other side surface 6b of the integral shroud 6A is formed on a flat surface without a concave groove. The viscoelastic damper 30 is the same as the viscoelastic damper 10 of the first embodiment shown in FIG. 8, and a viscoelastic member is interposed between the pair of first plate portion 31 and second plate portion 32. 33 is sandwiched, and the shape thereof is a protruding shape (protruding shape portion T) that can be engaged with the concave groove 61.

In the second embodiment, when a fluctuating force acts on the turbine blade, sliding friction occurs between the viscoelastic damper 30 and the integral shroud 6. Further, as in the first embodiment described above, accompanying the deformation of the viscoelastic damper 30, internal damping occurs in the viscoelastic member 13 in the viscoelastic damper 30, and kinetic energy is converted into internal thermal energy. become.
Further, the damping performance can be adjusted by rearranging the viscoelastic damper 30.

  As mentioned above, although embodiment of the damping member for rotary machines by this invention was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it can change suitably.

  For example, in the present embodiment, the gas turbine rotor blade 1 and the integral shroud 6 are applied as the rotating machine member, but the present invention is not limited to this. It is also possible to apply.

  Moreover, it is set as the structure which provides a viscoelastic material separately from the viscoelastic member mentioned above between at least one among the 1st board part 11 (31) and the 2nd board part 12 (32), and the member for rotary machines. In this case, the attenuation effect can be further enhanced.

  Furthermore, in the viscoelastic dampers 10 and 30 according to the above-described embodiments, one layer of the viscoelastic members 13 and 33 is sandwiched between the pair of the first plate portion 11 (31) and the second plate portion 12 (32). However, the present invention is not limited to such a laminated structure, and for example, a structure in which a plurality of viscoelastic members 13 and plate portions are alternately laminated may be employed.

  In addition, it is possible to appropriately replace the constituent elements in the above-described embodiments with well-known constituent elements without departing from the spirit of the present invention, and the above-described embodiments may be appropriately combined.

1, 1A, 1B Gas turbine blade (member for rotating machinery)
2 Blade root 3 Shank 4, 4A, 4B Platform 4a, 4b Side surface 5, 5A, 5B Wing part 6, 6A, 6B Integral shroud (member for rotating machine)
6a, 6b Side surface 10, 30 Viscoelastic damper (damping member body)
11, 31 1st plate part 12, 32 2nd plate part 13, 33 Viscoelastic member S Crevice T Projection shape part

Claims (2)

A damping member body disposed between a pair of rotating machine members that vibrate relatively,
The damping member body is
A first plate portion in contact with one of the rotary machine members;
A second plate portion in contact with the other rotary machine member;
A viscoelastic member interposed between the first plate portion and the second plate portion;
A damping member for a rotating machine, comprising: Either one of the pair of rotating machine members is provided with a concave groove on a side surface on the damping member main body side,
2. The damping member for a rotary machine according to claim 1, wherein a part of the damping member main body has a protruding shape bent along the concave groove.

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