JP7365942B2 - Stator blade ring of axial flow rotating machine and axial flow rotating machine - Google Patents

Description

The present disclosure relates to a stator vane ring that changes the natural frequency of the stator vane ring of the axial-flow rotary machine, and to an axial-flow rotary machine.

A stator vane ring of a compressor of an axial flow rotary machine is subjected to a periodic fluid force determined by the number of blades and the rotation speed of the rotor blades on the upstream side and the downstream side. The periodic fluid force acts as an excitation force on the stator vane ring of the compressor, causing the stator vane ring to vibrate. So far, the compressor has been described, but the same applies to the turbine.

Axial flow rotating machines are designed to avoid resonance that occurs when the natural frequency and excitation frequency match. The natural frequency of the stator blade ring varies depending on factors such as the material, shape, and support method of the components. Therefore, resonance is generally avoided by designing the axial-flow rotating machine so that the natural frequencies of the components thereof do not match the excitation frequencies under normal use of the axial-flow rotating machine.

By the way, among axial flow rotary machines, gas turbine engines used in aircraft engines may require rapid acceleration during use. Furthermore, if the flight envelope expressed in terms of altitude and aircraft speed is wide, the rotation speed will change because the pressure and temperature of the air at the engine inlet will change as the altitude and aircraft speed change. Therefore, unlike a gas turbine engine for power generation, it can be operated at a wide range of rotation speeds. Considering flight safety, it is necessary to prevent resonance from occurring over a wide range of rotational speeds.

On the other hand, it is possible to deal with this problem by increasing the structural strength of the stator blade so that the stator blade can withstand the dynamic stress caused by the resonance that occurs when the natural frequency and the excitation frequency match. One way to increase the structural strength of a blade is to increase the thickness of the stator blade. However, one of the disadvantages of increasing the thickness of the stator blades is an increase in pressure loss in the stator blade portion. This is because, as the thickness of the stator blade increases, the blockage that blocks the fluid flow path becomes larger, and the pressure loss in the stator blade portion increases. When the pressure loss at the stator blade increases, in the case of the stator blade of a compressor, the pressure of the air compressed by the rotor blade decreases when it passes through the stator blade. In addition, in the case of turbine stator blades, the pressure decreases when the air passes through the stator blades, reducing the pressure recovered by the rotor blades. As a result, the performance of the axial flow rotating machine as a whole deteriorates. Therefore, it is necessary to avoid resonance due to coincidence of the natural frequency and the excitation frequency while keeping the thickness of the stationary blade thin.

As a conventional technique, as described in Patent Document 1, a piezoelectric element is provided at the contact portion of a rotor blade shroud with an adjacent rotor blade shroud, and the contact reaction force acting between the rotor blade shrouds can be adjusted. An invention is disclosed in which vibrations are damped by applying an appropriate damping force to a rotor blade.

Japanese Patent Application Publication No. 2003-138904

However, since the above-mentioned disclosure deals with the excitation force acting on the rotor blade by applying a damping force, there is a problem in that it is impossible to avoid coincidence between the natural frequency and the excitation frequency. Ta.

The present disclosure has been made in view of the above problems, and by changing the support rigidity of the stator blade ring, the natural frequency of the stator blade ring is changed, and the natural frequency of the stator blade ring and the excitation frequency are matched. An object of the present invention is to provide a stator vane ring for an axial flow rotating machine and an axial flow rotating machine that make it possible to avoid resonance caused by the axial flow rotating machine.

In order to solve the above-mentioned problems and achieve the purpose, a stator vane ring for an axial flow rotating machine according to the present disclosure includes a plurality of stator blades, an outer circumferential shroud provided at the tips of the plurality of stator blades, and a plurality of stator blades. an inner shroud provided at the root of the stator blade, an outer shroud, and one or more support members provided on one of the inner shrouds; and a fixing member provided opposite the support member. , one or more restraint parts that changeably restrain the restraint state of the support member relative to the fixing member, and a control part that controls the restraint state of the restraint part in a changeable manner.

An axial flow rotary machine according to the present disclosure includes the stator vane ring of the axial flow rotary machine described above.

According to the present disclosure, by changing the support rigidity of the stator blade ring, the natural frequency of the stator blade ring is changed so that the natural frequency of the stator blade ring and the excitation frequency do not match at the rotation speed within the operating range. This makes it possible to avoid resonance due to coincidence of the natural frequency of the stator blade ring and the excitation frequency.

FIG. 1 is a schematic diagram showing the overall configuration of an axial flow rotating machine to which the present disclosure is applied. FIG. 2 is an explanatory diagram illustrating resonance within the operating range related to the problem of the present disclosure. FIG. 3 is a schematic diagram showing a stator blade ring of the axial flow rotary machine of the present disclosure. FIG. 4 is a schematic diagram showing a first embodiment of a restraining portion of a stator vane ring according to the present disclosure. FIG. 5 is a schematic diagram showing a second embodiment of the constraint portion of the stator vane ring of the present disclosure. FIG. 6 is a schematic diagram showing a third embodiment of the constraint portion of the stator vane ring of the present disclosure. FIG. 7 is an explanatory diagram showing a first example of a change in the natural frequency of a stator blade ring using the stator blade ring control unit of the present disclosure. FIG. 8 is an explanatory diagram showing a second example of a change in the natural frequency of a stator blade ring using the stator blade ring control unit of the present disclosure. FIG. 9 is an explanatory diagram showing a third example of changing the natural frequency of a stator blade ring using the stator blade ring control unit of the present disclosure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of stator vane rings for axial flow rotary machines according to the present disclosure will be described in detail below based on the drawings. Note that this disclosure is not limited to this example.

FIG. 1 is a schematic diagram showing the overall configuration of an axial flow rotating machine to which the present disclosure is applied. Examples of the axial rotating machine according to the present disclosure include aircraft turbofan engines, turbojet engines, turboprop engines, turboshaft engines, geared turbofan engines, turbo ramjet engines, gas turbine engines for power generation, and marine vessels. Examples include, but are not limited to, gas turbine engines. In the following explanation, an aircraft turbofan engine will be used as an example.

As shown in FIG. 1, the turbofan engine 1 includes a fan 2, a compressor 3, a combustion chamber 4, and a turbine 5. The basic operation of the turbofan engine 1 is that the fan 2 rotates along the rotating shaft 6, and the compressor 3 compresses the sucked fluid (air in this embodiment) to a higher temperature and pressure. The combustion chamber 4 mixes fuel with a fluid compressed to high temperature and high pressure by the compressor 3, and ignites the mixture, thereby imparting thermal energy to the fluid. The turbine 5 converts the thermal energy of the expanding combustion gas into kinetic energy, and drives the fan 2 and the compressor 3, which are attached to the same shaft as the turbine 5. The combustion gas that has passed through the turbine 5 is then exhausted from the exhaust duct. Note that the compressor 3 may be a multi-shaft type compressor that is composed of a plurality of compressors, each of which is assembled to a separate shaft. This also applies to the turbine 5.

The compressor 3 includes a rotor blade, a stator blade, a disk to which the rotor blade is assembled, an outer shroud formed at both ends of the stator blade, an inner shroud, and an inner shroud of the inner shroud of the stator blade. It includes a seal holding plate assembled on the circumferential side and a seal to which the seal holding plate is attached.

The turbine 5 includes a rotor blade, a stator blade, a disk to which the rotor blade is assembled, an outer shroud formed at both ends of the stator blade, an inner shroud, and an inner periphery of the inner shroud of the stator blade. It includes a seal retaining plate that is assembled to the side, and a seal to which the seal retaining plate is attached.

FIG. 2 is an explanatory diagram illustrating resonance related to the subject of the present disclosure. As shown in FIG. 2, when the excitation frequency of a predetermined order of the axial flow rotating machine matches the natural frequency of a predetermined order of the stator vane ring, resonance occurs. Even if the excitation frequency of a predetermined order does not match the natural frequency of the predetermined order, as the excitation frequency approaches the natural frequency, the amplitude due to resonance increases.

(Configuration of stationary blade ring)
FIG. 3 is a schematic diagram of a stator blade ring of an axial flow rotary machine according to the present disclosure. The stator vane ring of the axial flow rotary machine according to the present disclosure constitutes, for example, the stator vane portion of the compressor 3 described above. The stator vane rings are arranged in the circumferential direction to form a stator vane stage having an annular shape. The stator vane ring of the axial flow rotary machine according to the present disclosure includes a plurality of stator blades 75, an outer circumferential shroud 76 provided at the tips of the plurality of stator blades 75, and an inner shroud 76 provided at the root portion of the plurality of stator blades 75. One or more support members 73 (73A, 73B, 73C) provided on one of the circumferential shroud 74, the outer shroud 76, and the inner shroud 74, and a fixing member provided opposite the support member 73. It includes a member 72, one or more restraint parts that changeably restrain the restraint state of the support member 73 with respect to the fixed member 72, and a control part 8 that controls the restraint state of the restraint part so that the restraint state can be changed.

The outer shroud 76 has the purpose of sealing the compressed air at the tips of the blades by making the tips of the blades have a common integral structure for multiple blades, thereby preventing the compressed air from reaching the casing. The structure is formed to prevent the inflow of water.

The inner shroud 74 has a common integral structure at the root of the blade for the purpose of sealing the compressed air at the root of the blade. It is formed in a structure that prevents air from entering.

The support member 73 is a member that has a function of supporting the stator blade ring. It is preferable that the support member 73 is formed of a member having enough strength to support the stator vane ring. It is preferable that the support member 73 is formed in a shape that has a function of supporting the stator vane ring. The support member 73 is provided on the inner peripheral surface of the inner shroud 74 . The support member 73 has an inner peripheral end shaped to sandwich the fixing member 72, for example, a concave shape.

The fixing member 72 is a member to which the stator blade ring is fixed via the support member 73. The fixing member 72 is formed of a member having enough strength to fix the stationary blade ring via the support member 73. The fixing member 72 is formed into a shape that has the function of supporting the stationary blade ring via the support member 73. The fixing member 72 is, for example, a seal holding plate. The seal holding plate is a member that has the function of holding the seal 71. The seal retaining plate is provided on the inner circumferential side of the inner circumferential shroud 74 and is provided facing the support member 73. Specifically, the seal holding plate is arranged so as to be sandwiched between support members 73 having a concave shape. The seal holding plate includes a seal 71. An example of the seal provided on the seal holding plate is a labyrinth seal. The labyrinth seal is composed of a honeycomb-shaped seal receiving surface and sawtooth-shaped seal tooth surfaces.

The restraint section has a function of restraining the support member 73 with respect to the fixing member 72 so that the restraint state of the support member 73 can be changed. In the restraining portion, as described above, the support member 73 is provided on the inner circumferential shroud 74, and the fixing member 72 is a seal retaining plate.

The control unit 8 has a function of controlling the restraint state of the restraint unit in a changeable manner. The control unit 8 provided in the stator vane ring may constitute a part of the control unit of the axial flow rotating machine, or may communicate with the control unit provided outside the axial flow rotating machine by radio or electrical communication. It may also be a control unit connected via a line. The control unit 8 includes, for example, an integrated circuit such as a CPU (Central Processing Unit).

The stator vane ring of the axial flow rotary machine according to the present disclosure has the above-described configuration, so that the restraint state of the support member 73 provided in the stator vane ring is changed by the control of the control unit 8, and the stator vane ring is Support rigidity can be changed. Therefore, by changing the support rigidity of the stator blade ring, the natural frequency of the stator blade ring can be changed.

(Configuration of restraint part of stator vane ring)
A restraining portion according to one aspect of the present disclosure includes a biasing member that is provided between a support member and a fixing member, and that fixes the fixing member by pressing the fixing member against the support member, and a biasing member that suppresses a load acting on the biasing member. It is preferable to include a load bearing member to be applied.

The biasing member is a member that has a function of generating biasing force by storing energy. As the biasing member, a spring such as a plate spring or a coil spring can be used, but the present invention is not limited thereto.

The load bearing member is a member having a function of applying a load. As the load bearing member, a piezoelectric element, a hydraulic actuator, an electric actuator, etc. can be used, but the present invention is not limited thereto.

A stator vane ring of an axial flow rotary machine including a restraining portion according to an aspect of the present disclosure has the above-described configuration, thereby generating a load of the load-bearing member, thereby generating a load that opposes the biasing force of the biasing member. occurs, and the state in which the fixing member is supported by the biasing member changes. As a result, the support rigidity of the stator blade ring changes, and the natural frequency of the stator blade ring can be changed.

(First embodiment of restraint part of stator vane ring)
FIG. 4 is a schematic diagram showing a first embodiment of a restraining portion of a stator vane ring according to the present disclosure. The restraining portion of the stator vane ring according to the first embodiment of the present disclosure includes a leaf spring 77 as a biasing member, the outer side of the bent portion being in contact with the fixing member 72, and the portion of the securing member 72 where the leaf spring 77 comes into contact is A piezoelectric element 78 is provided on the opposite side as a load bearing member.

The leaf spring 77 is formed by sheet metal processing a flat member. The shape of the leaf spring is preferably a flat plate with a bent central portion. The material of the leaf spring is not particularly limited, but stainless steel may be used.

The piezoelectric element 78 includes a piezoelectric material whose shape changes when a voltage is applied, an electrode to which a voltage from a power supply is applied, and an insulator. Piezoelectric elements have characteristics such as high-speed response to voltage and fine control of shape. Piezoelectric materials having a piezoelectric effect or an inverse piezoelectric effect include lead zirconate titanate (PZT) ceramics, piezoelectric single crystals, piezoelectric polymers, piezoelectric composites, and piezoelectric laminates.

The stator vane ring of an axial flow rotary machine including the restraint part according to the first embodiment of the stator vane ring of the present disclosure has the above-described configuration, so that the voltage can be applied to the piezoelectric element 78 as shown in FIG. Before (when no voltage is applied), the piezoelectric element 78 is in a contracted state, so the fixing member 72 is biased by the plate spring 77 and comes into surface contact with the support member 73 . On the other hand, by applying a voltage to the piezoelectric element 78, the piezoelectric element 78 expands, and a load that opposes the biasing force of the leaf spring 77 is generated. As a result, the support state of the fixed member 72 held between the leaf spring 77 and the piezoelectric element 78 changes from surface contact to point contact as shown in FIG. 4, and the support rigidity of the stator vane ring changes. This allows the natural frequency of the stator blade ring to be changed.

(Operation of the control section of the first embodiment)
The control unit for a stator vane ring including a restraint unit according to the first embodiment of the present disclosure is such that the excitation frequency of a predetermined order of the axial flow rotating machine is set to a predetermined value with respect to the natural frequency of the predetermined order of the stator vane ring. A voltage of a predetermined value, which is set such that the excitation frequency of the predetermined order does not match the natural frequency of the predetermined order, for the piezoelectric element connected to the power supply when the value in the range is reached. By applying , the dimensions of the piezoelectric element to which the voltage is applied are changed, the load opposing the biasing force of the leaf spring is changed, and the piezoelectric element is controlled so that the support rigidity of the restraint part is changed.

The excitation frequency of a predetermined order means a value that is an integral multiple of the fundamental frequency of the axial flow rotating machine. Therefore, the excitation frequency of a predetermined order includes the fundamental frequency, ie, one time the fundamental frequency. When the excitation frequency of a predetermined order matches the natural frequency of a predetermined order that matches the excitation frequency, resonance occurs and dynamic stress acts on the stationary blade.

Even if the excitation frequency of a given order that matches the natural frequency of a given order of the stator vane ring reaches a value within a given range, the amplitude of the stator vane increases due to resonance. However, dynamic stress acts on the stator blade. Therefore, "when the excitation frequency of a predetermined order of the axial flow rotating machine reaches a value within a predetermined range with respect to the natural frequency of a predetermined order of the stator blade ring" means that the excitation frequency of a predetermined order is , the dynamic stress acting on the stator vane caused by the resonance that occurs as it approaches the natural frequency of a given order is the boundary value of the range that ensures a sufficient safety margin with respect to the yield strength of the stator vane material. This means that the value is reached.

The piezoelectric element expands in size in proportion to the applied voltage. According to the relationship between the change in the dimensions of the piezoelectric material and the voltage, it is possible to determine the voltage value at which the support rigidity of the stator vane ring changes. That is, by investigating the relationship between the support rigidity of the stator blade ring and the natural frequency of the stator blade ring through numerical simulation or experiment, it is possible to determine a voltage value that allows resonance to be avoided. Therefore, "a voltage of a predetermined value that is set so that the excitation frequency of a predetermined order does not match the natural frequency of a predetermined order" means that the excitation frequency of a predetermined order does not match the natural frequency of a predetermined order of the stator blade ring. When the natural frequency of the stator vane ring reaches a value within a predetermined range, the natural frequency of the stator vane ring is determined to be sufficient for the excitation frequency of the predetermined order, taking into account the yield strength of the material of the stator vane. It means a voltage value that can be changed to a distant value with a safety margin.

FIG. 7 is an explanatory diagram showing an example of the result of changing the natural frequency of the stator blade ring by the above-mentioned control unit. When the excitation frequency of a predetermined order of the axial flow rotating machine reaches a value within a predetermined range with respect to the natural frequency of a predetermined order that matches it, the piezoelectric element is set so that it does not match the natural frequency. By applying a predetermined voltage, the dimensions of the piezoelectric element are changed in a direction that reduces the natural frequency, and the supporting rigidity of the stator vane ring is changed, thereby changing the natural frequency in a direction that reduces the natural frequency. In this example, the natural frequency is changed so that it straddles the excitation frequency, is below the excitation frequency, and is sufficiently far away from the excitation frequency to prevent the occurrence of resonance. To avoid.

FIG. 8 is an explanatory diagram showing another example of the result of changing the natural frequency of the stator blade ring by the above-mentioned control unit. In this example, the support rigidity of the stator blade ring is changed in a direction that increases the natural frequency of the stator blade ring. After that, as the excitation frequency increases, if the excitation frequency reaches a predetermined range with respect to the natural frequency again, the same control is performed again to increase the natural frequency and avoid resonance. . At this time, the natural frequency is controlled in stages as the low-order excitation frequency approaches the natural frequency so that the value exceeds the low-order excitation frequency and is less than the high-order excitation frequency. Ru. Note that the specific control results of the natural frequency by the above-mentioned control section are not limited to the modes shown in FIGS. 7 and 8.

By having the above-mentioned configuration, the control unit for the stator vane ring including the restraint unit according to the first embodiment of the present disclosure can control the excitation frequency of the predetermined order of the axial flow rotating machine to the characteristic of the predetermined order of the stator vane ring. A voltage of a predetermined value that is set so that the excitation frequency of a predetermined order does not match the natural frequency of a predetermined order for the piezoelectric element when a value in a predetermined range for the vibration frequency is reached. By applying , the dimensions of the piezoelectric element to which voltage is applied change, the load that opposes the urging force of the leaf spring changes, the supporting rigidity of the stator blade ring changes, and the natural frequency of the stator blade ring changes. This change makes it possible to avoid resonance. Since it is possible to avoid resonance, there is no need to increase the thickness of the stator blades in order to withstand the dynamic stress that is applied to the stator blades when resonance occurs, contributing to improved performance of axial flow rotating machines. You can.

(Second embodiment of restraint part of stator vane ring)
FIG. 5 is a schematic diagram showing a second embodiment of the constraint portion of the stator vane ring of the present disclosure. The restraining portion of the stator vane ring according to the second embodiment of the present disclosure includes a plate spring 77 as a biasing member, the outer side of the bent portion being in contact with the fixed member 72, and a piezoelectric element 78 inside the bent portion of the plate spring 77. Equipped with.

The leaf spring 77 may be the same as that used in the first embodiment of the restraining portion of the stationary vane ring.

The piezoelectric element 78 uses a bendable piezoelectric element. A bendable piezoelectric element can be obtained by using a piezoelectric film produced by mixing piezoelectric ceramic powder and a piezoelectric sol-gel solution, stirring, coating, and sintering. The piezoelectric element 78 is installed inside the bent portion of the leaf spring 77.

The stator vane ring of an axial flow rotary machine including a restraining portion according to the second embodiment of the present disclosure has the above-described configuration, so that when a voltage is applied to the piezoelectric element 78, the piezoelectric element 78 expands and the plate This creates an effect of widening the bent portion of the spring 77 from the inside. As a result, the supporting state of the fixed member 72 gripped by the leaf spring 77 changes from surface contact to non-contact state as shown in FIG. The natural frequency can be changed.

(Operation of the control unit of the second embodiment)
The control unit for a stator vane ring including a restraint unit according to the second embodiment of the present disclosure is arranged such that the excitation frequency of a predetermined order of the axial flow rotating machine is within a predetermined range with respect to the natural frequency of a predetermined order of the stator vane ring. When the value of is reached, a voltage of a predetermined value is applied to the piezoelectric element connected to the power supply, which is set so that the excitation frequency of the predetermined order does not match the natural frequency of the predetermined order. By applying the voltage, the piezoelectric element is controlled so that the dimensions of the piezoelectric element to which the voltage is applied change, the biasing force of the leaf spring changes, and the support rigidity of the restraint part changes.

The meaning of "when the excitation frequency of a predetermined order of the axial flow rotating machine reaches a predetermined value with respect to the natural frequency of a predetermined order of the stator blade ring" is defined by the constraint section of the first embodiment of the present disclosure. The meaning of the term is the same as that used in the control section of the stator vane ring.

Similarly, "a voltage of a predetermined value that is set such that the excitation frequency of a predetermined order does not match the natural frequency of a predetermined order" means that the static The meanings of the terms used in the control section of the blade ring are the same.

FIG. 9 is an explanatory diagram showing an example of the result of changing the natural frequency of the stator blade ring by the above-mentioned control unit. When the excitation frequency of a predetermined order of the axial flow rotating machine reaches a value within a predetermined range with respect to the natural frequency of the same order, a predetermined voltage set so as not to match the natural frequency is applied. By applying an electric current to the piezoelectric element, changing the dimensions of the piezoelectric element, and changing the support rigidity of the stator vane ring, the natural frequency is changed and resonance is avoided. In the example shown in FIG. 9, the support rigidity of the stator blade ring is changed in a direction that increases the natural frequency of the stator blade ring. Specifically, as the excitation frequency increases, the natural frequency is continuously increased so that the natural frequency exceeds the low-order excitation frequency and is less than the high-order excitation frequency. change and avoid resonance. Note that the specific control result of the natural frequency by the above-mentioned control unit is not limited to the mode shown in FIG. 9 .

By having the above-described configuration, the control unit for the stator vane ring including the restraint unit according to the second embodiment of the present disclosure can control the excitation frequency of the predetermined order of the axial flow rotating machine to the characteristic of the predetermined order of the stator vane ring. When the vibration frequency reaches a value within a predetermined range, the excitation frequency of the predetermined order of the piezoelectric element connected to the power supply is set so that it does not match the natural frequency of the predetermined order. In addition, by applying a voltage of a predetermined value, the dimensions of the piezoelectric element to which the voltage is applied change, the biasing force of the leaf spring changes, the supporting rigidity of the stator vane ring changes, and the characteristic of the stator vane ring changes. By changing the frequency, resonance can be avoided. Since it is possible to avoid resonance, there is no need to increase the thickness of the stator blades in order to withstand the dynamic stress that is applied to the stator blades when resonance occurs, contributing to improved performance of axial flow rotating machines. You can.

(Third embodiment of restraint part of stator vane ring)
FIG. 6 is a schematic diagram showing a third embodiment of the constraint portion of the stator vane ring of the present disclosure. The restraining portion of the stator vane ring according to the third embodiment of the present disclosure includes a fixing member 72 in which one or more holes are formed, and piezoelectric elements 78 of the same number as the one or more holes, and the piezoelectric elements 78 is inserted into one or more holes formed in the fixing member 72, and both ends thereof are fixed to the support member 73.

The hole formed in the fixing member 72 is formed in a circular shape with a diameter that allows insertion of the piezoelectric element.

The stator vane ring of an axial flow rotary machine including a restraining part according to the third embodiment of the present disclosure has the above-described configuration, so that when a voltage is applied to the piezoelectric element 78, the piezoelectric element 78 expands, and as shown in FIG. As shown in 6, the supported state in which the contact range between the hole formed in the fixing member and the piezoelectric element is narrow changes to the supported state in which the contact range is wide. As a result, the supporting state of the fixed member 72 changes, and the support rigidity of the stator blade ring changes, so that the natural frequency of the stator blade ring can be changed.

(Operation of the control section of the third embodiment)
The control unit for a stator vane ring including a restraint unit according to the third embodiment of the present disclosure is arranged such that the excitation frequency of a predetermined order of the axial flow rotating machine is within a predetermined range with respect to the natural frequency of a predetermined order of the stator vane ring. When the value of is reached, a voltage of a predetermined value is applied to the piezoelectric element connected to the power supply, which is set so that the excitation frequency of the predetermined order does not match the natural frequency of the predetermined order. By applying the voltage, the dimensions of the piezoelectric element to which the voltage of a predetermined value is applied change, and the piezoelectric element is controlled so that the support rigidity of the restraint part changes.

The meaning of "when the excitation frequency of a predetermined order of the axial flow rotating machine reaches a predetermined value with respect to the natural frequency of a predetermined order of the stator blade ring" is defined by the constraint section of the first embodiment of the present disclosure. The meaning of the term is the same as that used in the control section of the stator vane ring.

Similarly, "a voltage of a predetermined value that is set such that the excitation frequency of a predetermined order does not match the natural frequency of a predetermined order" means that the static The meanings of the terms used in the control section of the blade ring are the same.

By having the above-described configuration, the control unit for a stator vane ring equipped with a restraint unit according to the third embodiment of the present disclosure can control the excitation frequency of a predetermined order of the axial flow rotating machine to the characteristic of a predetermined order of the stator vane ring. When the vibration frequency reaches a value within a predetermined range, the excitation frequency of the predetermined order of the piezoelectric element connected to the power supply is set so that it does not match the natural frequency of the predetermined order. In addition, by applying a voltage of a predetermined value, the dimensions of the piezoelectric element to which the voltage is applied change, the support rigidity of the restraint part changes, and the natural frequency of the stator vane ring changes, causing resonance. It is possible to avoid this. Since it is possible to avoid resonance, there is no need to increase the thickness of the stator blades in order to withstand the dynamic stress that is applied to the stator blades when resonance occurs, contributing to improved performance of axial flow rotating machines. You can.

Note that in the stator vane ring of the axial flow rotary machine according to the present disclosure described above, the support member 73 is provided on the inner peripheral side shroud 74 and the fixing member 72 is a seal holding plate, but the structure is not limited to this. The support member 73 may be provided on the outer shroud 76, and the fixing member 72 may be applied to a casing provided on the outer circumferential side of the outer shroud.

Moreover, although the stationary blade ring of the axial flow rotary machine according to the present disclosure described above is applied to the turbofan engine 1, it may be applied to other axial flow rotary machines.

The stator vane ring of the axial flow rotary machine according to the present disclosure includes a plurality of stator blades 75, an outer peripheral side shroud 76 provided at the tips of the plurality of stator blades 75, and a stator blade ring provided at the root of the plurality of stator blades 75. An inner shroud 74, an outer shroud 76, one or more support members 73 provided on one of the inner shrouds 74, and a fixing member 72 provided opposite the support member 73. , one or more restraint parts that changeably restrain the restraint state of the support member 73 with respect to the fixing member 72, and a control part 8 that controls the restraint state of the restraint part in a changeable manner.

According to this configuration, by changing the support rigidity of the stator blade ring, the natural frequency of the stator blade ring can be changed so that the natural frequency of the stator blade ring and the excitation frequency do not match. It becomes possible to avoid resonance due to coincidence of the natural frequency of the ring and the excitation frequency.

The restraint part is provided between the support member 73 and the fixing member 72, and includes a biasing member that fixes the fixing member 72 by pressing it against the support member 73, and a biasing member that acts on the biasing member. and a load bearing member that applies a load.

According to this configuration, the restraint state between the support member 73 and the fixing member 72 can be changed with a simple configuration using the urging member and the load application member.

The biasing member includes a leaf spring 77 whose bent portion is in contact with the fixing member 72 on the outside, and the load-bearing member is provided on the opposite side of the fixing member 72 from where the leaf spring 77 comes into contact. A piezoelectric element 78 is provided.

According to this configuration, the contact state of the fixing member 72 can be changed between surface contact and point contact using the leaf spring 77 and the piezoelectric element 78. The restraint state can be changed appropriately.

The control unit 8 is connected to the power supply device when the excitation frequency of a predetermined order of the axial flow rotating machine reaches a value within a predetermined range with respect to the natural frequency of the predetermined order of the stator blade ring. Further, a voltage is applied to the piezoelectric element 78 by applying a voltage of a predetermined value, which is set so that the excitation frequency of the predetermined order does not match the natural frequency of the predetermined order. The dimensions of the piezoelectric element 78 are changed, the load opposing the biasing force of the leaf spring 77 is changed, and the support rigidity of the restraining portion is controlled to change.

According to this configuration, by controlling the application of voltage to the piezoelectric element 78, it is possible to change the support rigidity of the restraining portion so that the natural frequency and the excitation frequency do not match.

The biasing member includes a plate spring 77 with the outside of the bent portion in contact with the fixing member, and the load applying member includes a piezoelectric element 78 inside the bent portion of the plate spring 77.

According to this configuration, since the contact pressure of the fixing member 72 can be continuously changed using the leaf spring 77 and the piezoelectric element 78, the restraint state between the support member 73 and the fixing member 72 can be changed in more detail. can do.

The control unit is connected to a power supply device when the excitation frequency of a predetermined order of the axial flow rotating machine reaches a value in a predetermined range with respect to the natural frequency of the predetermined order of the stator blade ring. , a voltage is applied to the piezoelectric element 78 by applying a voltage of a predetermined value, which is set such that the excitation frequency of the predetermined order does not match the natural frequency of the predetermined order. Control is performed so that the dimensions of the piezoelectric element 78 change, the biasing force of the plate spring 77 changes, and the support rigidity of the restraint part changes.

According to this configuration, by controlling the application of voltage to the piezoelectric element 78, it is possible to change the support rigidity of the restraining portion so that the natural frequency and the excitation frequency do not match.

The restraint section includes the fixing member in which one or more holes are formed, and a number of piezoelectric elements corresponding to the one or more holes, and the piezoelectric elements are arranged in one or more holes formed in the fixing member. After being inserted into the hole, both ends are fixed to the support member.

According to this configuration, since the biasing member can be omitted, the restraining portion can be configured more simply.

The control unit is connected to a power supply device when the excitation frequency of a predetermined order of the axial flow rotating machine reaches a value in a predetermined range with respect to the natural frequency of the predetermined order of the stator blade ring. , by applying a voltage of a predetermined value to the piezoelectric element such that the excitation frequency of the predetermined order does not match the natural frequency of the predetermined order, the voltage is applied to the piezoelectric element. Control is performed so that the dimensions of the piezoelectric element change and the support rigidity of the restraint part changes.

According to this configuration, by controlling the application of voltage to the piezoelectric element 78, it is possible to change the support rigidity of the restraining portion so that the natural frequency and the excitation frequency do not match.

The support member is provided on the inner shroud, and the fixing member includes a seal retaining plate.

According to this configuration, since the restraining portion can be provided on the inner peripheral side shroud, the support rigidity can be changed using the piezoelectric element 78.

The support member may be provided on the outer shroud, and the fixing member may include a casing.

The axial flow rotary machine includes the stator vane ring of the axial flow rotary machine described above.

According to this configuration, it is possible to provide an axial flow rotary machine in which resonance of the stator blade ring is suppressed.

1 Turbofan engine 2 Fan 3 Compressor 4 Combustion chamber 5 Turbine 6 Rotating shaft

Claims (11)

a plurality of stationary blades;
an outer peripheral shroud provided at the tips of the plurality of stator blades;
an inner circumferential shroud provided at the root portion of the plurality of stator blades;
one or more support members provided on one of the outer shroud and the inner shroud;
a fixing member provided opposite to the support member;
one or more restraint portions that restrain the support member in a manner that can change the restraint state of the support member relative to the fixing member;
a control unit configured to changeably control the restraint state of the restraint unit;
Equipped with
The restraint section includes one or more piezoelectric elements,
The control unit is configured to:
The piezoelectric element connected to the power supply device is set such that the excitation frequency of the predetermined order does not match the natural frequency of the predetermined order.
By applying a voltage of a predetermined value,
changing the restraint state by changing the dimensions of the piezoelectric element to which a voltage is applied and changing the support rigidity of the restraint part;
Stator blade ring of axial flow rotating machine. The restraining part is provided between the supporting member and the fixing member,
an urging member that fixes the fixing member by pressing it against the support member;
a load-bearing member that applies a load acting on the biasing member;
The stationary blade ring for an axial flow rotating machine according to claim 1, comprising: The biasing member includes a leaf spring whose outer side of a bent portion is in contact with the fixing member, and
The stator vane ring for an axial flow rotary machine according to claim 2, wherein the load bearing member includes a piezoelectric element on the opposite side of the portion of the fixed member that is in contact with the leaf spring. A voltage of a predetermined value applied by the control section changes the dimensions of the piezoelectric element to which the voltage is applied, changes the load opposing the biasing force of the leaf spring, and changes the support rigidity of the restraint section. A stator blade ring for an axial flow rotating machine according to claim 3. The biasing member includes a leaf spring whose outer side of a bent portion is in contact with the fixing member, and
The stator vane ring for an axial flow rotary machine according to claim 2, wherein the load bearing member includes a piezoelectric element inside a bent portion of the leaf spring. According to claim 5, the voltage of a predetermined value applied by the control unit changes the dimensions of the piezoelectric element to which the voltage is applied, changes the biasing force of the leaf spring, and changes the support rigidity of the restraint part. Stator blade ring of the described axial flow rotating machine. The restraining portion includes the fixing member in which one or more holes are formed;
comprising a number of piezoelectric elements corresponding to the one or more holes,
The stator vane ring for an axial flow rotary machine according to claim 1, wherein the piezoelectric element is inserted into one or more holes formed in the fixing member, and both ends thereof are fixed to the support member. The stator vane ring for an axial flow rotating machine according to claim 7 , wherein the voltage of a predetermined value applied by the control unit changes the dimensions of the piezoelectric element to which the voltage is applied, and the support rigidity of the restraint part changes. . The support member is provided on the inner shroud,
The fixing member includes a seal retaining plate.
A stator vane ring for an axial flow rotating machine according to any one of claims 2 to 8. The support member is provided on the outer shroud,
The fixing member includes a casing.
A stator vane ring for an axial flow rotating machine according to any one of claims 1 to 8. An axial-flow rotary machine, comprising the stator vane ring of the axial-flow rotary machine according to any one of claims 1 to 10.

Images