Blisk blade and rotary machine

Abstract

A blisk blade according to the present disclosure comprises: a disk part centered on an axis; and a plurality of blade parts extending radially outward from the outer peripheral surface of the disk part and arranged in a circumferential direction. On a main surface of the disk part, a detuning part extending in the circumferential direction about the axis is formed, said main surface facing the axial direction.

Description

Blisk blades and rotating machinery

[0001] This application claims priority to Japanese Patent Application No. 2023-211504, filed on December 14, 2023, the contents of which are incorporated herein by reference.

[0002] For example, rotary machines such as gas turbines, turbofan engines, and compressors mainly include a rotating shaft that can rotate about its axis, a plurality of rows of rotor blades attached to the rotating shaft, a casing that covers the rotor blade rows from the outer periphery, and a plurality of rows of stator blades arranged on the inner circumferential surface of the casing so as to alternate with the rotor blade rows in the axial direction. Each of the rotor blade rows and the stator blade rows includes a circular disk attached to the rotating shaft and a plurality of blades extending radially outward from the outer circumferential surface of the disk. Conventionally, the disk and the blades have generally been manufactured as separate, independent components.

[0003] In recent years, the increasing diameter of engines, i.e., the increasing length of blades, has led to a demand for lighter components. Therefore, attention has been drawn to a technology called a blisk blade, in which the disk and blade are integrated (see, for example, Patent Document 1 below). However, blisk blades have the problem of being prone to vibration because they do not provide structural frictional damping between the disk and the blade. For this reason, Patent Document 1 below proposes a technology in which the disk portion of the blisk blade is provided with multiple mistuned holes or grooves arranged at intervals in the circumferential direction.

[0004] Japanese Patent Application Laid-Open No. 2022-13322

[0005] However, when a plurality of mistuned portions are provided at intervals in the circumferential direction as described above, there is a problem in that it becomes more difficult to achieve vibration damping as the vibration nodal diameter decreases.

[0006] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a blisk blade and a rotary machine in which vibration is further suppressed.

[0007] In order to solve the above problems, the blisk blade according to the present disclosure is a blisk blade having a disk-shaped disk portion centered on an axis, and a plurality of blade portions extending radially outward from the outer peripheral surface of the disk portion and arranged in a circumferential direction, and a detuned portion extending circumferentially around the axis is formed on a main surface of the disk portion facing the axial direction.

[0008] A rotary machine according to the present disclosure includes the above-described blisk blades, a rotating shaft rotatable about the axis and supporting a plurality of the blisk blades, and a casing covering the plurality of blisk blades from an outer circumferential side.

[0009] According to the present disclosure, it is possible to provide a blisk blade and a rotary machine in which vibration is further suppressed.

[0010] FIG. 5 is a schematic cross-sectional view showing the configuration of a rotary machine according to a first embodiment of the present disclosure. FIG. 6 is a plan view showing the configuration of a blisk blade according to the first embodiment of the present disclosure. FIG. 7 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 8 is an example of a graph showing the relationship between the vibration frequency and the nodal diameter of the blisk blade according to the first embodiment of the present disclosure. FIG. 9 is a plan view showing the configuration of a blisk blade according to a second embodiment of the present disclosure. FIG. 10 is a cross-sectional view taken along line V-V in FIG. 5. FIG. 11 is a plan view showing the configuration of a blisk blade according to a third embodiment of the present disclosure. FIG. 12 is a plan view showing a modified example of a blisk blade common to each embodiment of the present disclosure.

[0011] <First embodiment> (Configuration of rotary machine) Hereinafter, a blisk blade 5 and a rotary machine according to a first embodiment of the present disclosure will be described with reference to Fig. 1 to Fig. 4. This blisk blade 5 is particularly suitable for use as a rotor blade of a rotary machine such as a gas turbine.

[0012] (Configuration of Aircraft Gas Turbine 100 ) As shown in FIG. 1 , an aircraft gas turbine 100 as a rotary machine includes a compressor 1 , a combustor 2 , and a turbine 3 .

[0013] The compressor 1 compresses air drawn in through an intake duct 10 to generate high-pressure air. The compressor 1 includes a compressor rotor 11 (rotating shaft), a compressor casing 12, a compressor rotor blade row 13, and a compressor stator vane row 15. The compressor rotor 11 is cylindrical and extends along an axis Am, and is rotatable about the axis Am. A plurality of compressor rotor blade rows 13 are arranged on the outer circumferential surface of the compressor rotor 11 at intervals in the direction of the axis Am. Each compressor rotor blade row 13 includes a plurality of compressor rotor blades 14 that extend radially outward from the outer circumferential surface of the compressor rotor 11 and are arranged circumferentially. The compressor casing 12 is cylindrical and covers the compressor rotor blade rows 13 from the outer circumferential side. A plurality of compressor stator vane rows 15 are arranged on the inner circumferential surface of the compressor casing 12. The compressor stator vane rows 15 are arranged alternately with the compressor rotor blade rows 13 in the direction of the axis Am. Each compressor stator vane row 15 has a plurality of compressor stator vanes 16 that protrude radially inward from the inner circumferential surface of the compressor casing 12 and are arranged in the circumferential direction.

[0014] The combustor 2 mixes fuel F with the high-pressure air generated by the compressor 1 and burns the mixture to generate high-temperature, high-pressure combustion gas G. The combustor 2 is provided between the compressor casing 12 and the turbine casing 22. The combustion gas G generated by the combustor 2 is supplied to the turbine 3.

[0015] The turbine 3 has a turbine rotor 21, a turbine casing 22, a turbine rotor blade row 23, and a turbine stator blade row 25. The turbine rotor 21 has a columnar shape extending along the axis Am and is rotatable about the axis Am. A plurality of turbine rotor blade rows 23 are arranged at intervals in the direction of the axis Am on the outer circumferential surface of the turbine rotor 21. Each turbine rotor blade row 23 has a plurality of turbine blades 24 that extend radially outward from the outer circumferential surface of the turbine rotor 21 and are arranged in the circumferential direction. The turbine casing 22 has a cylindrical shape that covers the turbine rotor blade rows 23 from the outer circumferential side. A plurality of turbine stator blade rows 25 are arranged on the inner circumferential surface of the turbine casing 22. The turbine stator blade rows 25 are arranged so as to alternate with the turbine rotor blade rows 23 in the direction of the axis Am. Each turbine stator blade row 25 has a plurality of turbine stator blades 26 that protrude radially inward from the inner circumferential surface of the turbine casing 22 and are arranged in the circumferential direction.

[0016] The compressor rotor 11 and the turbine rotor 21 are integrally connected in the direction of the axis Am to form a gas turbine rotor 91. The compressor casing 12 and the turbine casing 22 are integrally connected in the direction of the axis Am to form a gas turbine casing 92. In other words, the gas turbine rotor 91 is rotatable around the axis Am inside the gas turbine casing 92.

[0017] To operate the aircraft gas turbine 100, first, an external driving source rotates the compressor rotor 11 (gas turbine rotor 91). As the compressor rotor 11 rotates, external air is compressed sequentially to generate high-pressure air. This high-pressure air is supplied to the combustor 2 through the compressor casing 12. In the combustor 2, fuel F is mixed with the high-pressure air and then combusted, generating high-temperature, high-pressure combustion gas G. The combustion gas G is supplied to the turbine 3 through the turbine casing 22. In the turbine 3, the combustion gas G sequentially collides with a turbine rotor blade row 23 and a turbine stator blade row 25, thereby applying a rotational driving force to the turbine rotor 21 (gas turbine rotor 91). This rotational energy is primarily used to drive the compressor 1. The combustion gas G that has driven the turbine 3 has its flow velocity increased by the exhaust nozzle, becoming a jet that generates thrust and is then discharged to the outside through an injection port. In this embodiment, a single-shaft turbojet engine has been described as an example of the aircraft gas turbine 100. However, the invention is not limited to a single-shaft turbojet engine, and may be any type of aircraft gas turbine 100. In particular, the invention is suitable for a low-pressure turbine or turbofan of a multi-shaft turbofan engine.

[0018] (Configuration of the blisk blade 5) Next, the configuration of the compressor rotor blade row 13 will be described with reference to Figures 2 and 3. As shown in Figure 2, the compressor rotor blade row 13 has a disk portion 51, a blade portion 52, and a detuned portion 53. The disk portion 51 has a disk shape centered on the axis Am.

[0019] Blade portions 52 are provided on the outer periphery of the disk portion 51. The blade portions 52 extend radially outward from the outer periphery of the disk portion 51, and a plurality of blade portions 52 are arranged at intervals in the circumferential direction. These blade portions 52 correspond to the compressor rotor blades 14 described above. The disk portion 51 and the blade portions 52 are integrally formed from the same material. In other words, this compressor rotor blade row 13 constitutes a so-called blisk blade 5 in which the disk portion 51 and the blade portion 52 are integrated.

[0020] A detuning portion 53 is provided on the surface (principal surface 51a) of the disk portion 51 facing the axis Am. The detuning portion 53 is a structure for changing the vibration mode of the disk portion 51 to avoid resonance and coupled vibration. Specifically, the detuning portion 53 has a groove 61. The groove 61 forms a continuous ring shape centered on the axis Am and is a groove recessed from the principal surface 51a in the direction of the axis Am. As an example, the cross-sectional shape of the groove 61 is rectangular as shown in FIG. 3. The cross-sectional shape of the groove 61 may be semicircular or trapezoidal. The groove 61 serving as the detuning portion 53 is provided at a central position in the radial direction of the disk portion 51. The groove 61 may be biased radially inward or outward from this.

[0021] (Effects) In recent years, as the diameter of the aircraft gas turbine 100 has increased, i.e., the blades have become longer, there has been a demand for reducing the weight of these components. Therefore, attention has been drawn to the blisk blade 5, in which the disk and the blade are integrated. On the other hand, the blisk blade 5 has a problem in that it is prone to vibration because it does not provide structural frictional damping that occurs between the disk and the blade. To solve this problem, the present embodiment employs the above-described configurations.

[0022] According to the above configuration, a detuned portion 53 extending in the circumferential direction is provided on the main surface 51a of the disk portion 51. This changes the rigidity of the disk portion 51. This change in rigidity allows for arbitrary control of the vibration frequency when the entire blisk blade 5 is excited. Specifically, as shown by the dashed and double-dashed lines in the graph of FIG. 4 , the effect of changes in rigidity on the vibration frequency is greater, particularly in the primary vibration mode with a small nodal diameter (nodal diameter of approximately 0 to 3), than in modes with a large nodal diameter. According to the above configuration, the vibration characteristics (frequency) of the blisk blade 5 in such a low nodal diameter mode can be optimized, thereby preventing fatigue failure of the blisk blade 5. Specifically, it is possible to avoid a state in which the vibration frequency value coincides with the dashed "constant rotation speed line" shown in FIG. 4 . It is known that if this constant rotation speed line coincides with the vibration frequency, resonance or coupled vibration may occur. According to the above configuration, this frequency coincidence can be avoided, significantly reducing the possibility of resonance or coupled vibration. Therefore, it is possible to continue stable operation of a rotary machine to which the blisk blade 5 is applied for a long period of time. Note that the "nodal diameter mode" referred to here is a natural vibration mode similar to the vibration mode of a disk, and refers to a vibration mode in which nodes exist at several diameter positions, which are one wavelength, two wavelengths, etc., in the circumferential direction, just like the vibration mode of a disk. These wavelengths, i.e., the number of "nodes," are called the "nodal diameter."

[0023] According to the above configuration, the detuning portion 53 has a groove portion 61 provided in the main surface 51a. The provision of this groove reduces the rigidity of the disk portion 51. As a result, the vibration frequency of the blisk blade 5 when excited decreases (see the dashed line in FIG. 4). This makes it possible to optimize the vibration characteristics in the low nodal diameter mode. This makes it possible to avoid fatigue failure of the blisk blade 5. Therefore, it becomes possible to continue stable operation of a rotary machine to which the blisk blade 5 is applied for a long period of time.

[0024] With the above configuration, since the detuned portion 53 has a circular ring shape that is continuous in the circumferential direction, it is possible to suppress vibrations in the nodal diameter mode over the entire circumferential area. In addition, it is possible to create a mistuned state in the radial direction over the entire circumferential area. This makes it possible to further reduce the possibility of coupled vibrations and resonance.

[0025] The first embodiment of the present disclosure has been described above. Note that various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure.

[0026] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to Fig. 5 and Fig. 6. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0027] As shown in FIG. 5 or 6 , in this embodiment, the detuning portion 53 has a protrusion 62 instead of a groove 61. The protrusion 62 protrudes from the main surface 51 a of the disk portion 51 in the direction of the axis Am and forms a continuous ring shape centered on the axis Am. As shown in FIG. 5 , the cross-sectional shape of the protrusion 62 is rectangular, for example. However, the cross-sectional shape of the protrusion 62 may also be semicircular or trapezoidal. Furthermore, the protrusion 62 is provided at a central position in the radial direction of the disk portion 51. However, the protrusion 62 may be biased radially inward or outward from this.

[0028] (Effects) According to the above configuration, the detuning portion 53 has a protrusion 62 provided on the main surface 51a. The provision of this protrusion 62 increases the rigidity of the disk portion 51. As a result, the vibration frequency of the blisk blade 5 when excited also increases (see the two-dot chain line in FIG. 4). This makes it possible to optimize the vibration characteristics in the low nodal diameter mode. This makes it possible to avoid fatigue failure of the blisk blade 5. Therefore, it becomes possible to continue stable operation of a rotary machine to which the blisk blade 5 is applied for a long period of time.

[0029] With the above configuration, since the detuned portion 53 has a circular ring shape that is continuous in the circumferential direction, it is possible to suppress vibrations in the nodal diameter mode over the entire circumferential area. In addition, it is possible to create a mistuned state in the radial direction over the entire circumferential area. This makes it possible to further reduce the possibility of coupled vibrations and resonance.

[0030] The second embodiment of the present disclosure has been described above. Note that various changes and modifications can be made to the above configuration without departing from the spirit and scope of the present disclosure.

[0031] Third Embodiment Next, a third embodiment of the present disclosure will be described with reference to Fig. 7. Note that the same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0032] As shown in FIG. 7 , in this embodiment, the detuning portion 53 has small grooves 63 in addition to grooves 61. The small grooves 63 are provided alongside the grooves 61. That is, they are formed integrally with the outer periphery of the grooves 61. The small grooves 63 are recessed from the main surface 51 a of the disk portion 51 in the direction of the axis Am, and a plurality of small grooves 63 (five in one example) are provided at intervals in the circumferential direction. The small grooves 63 have a rectangular shape when viewed from the direction of the axis Am. The number of small grooves 63 may be any number as long as their common divisor does not equal the nodal diameter.

[0033] (Effects) According to the above configuration, in addition to the groove 61, there are a plurality of small grooves 63. This makes it possible to mistune vibration modes not only in the radial direction of the disk portion 51 but also in the circumferential direction. Therefore, it is possible to minimize the possibility of coupled vibrations and resonances that occur when various vibration modes are coupled together.

[0034] The third embodiment of the present disclosure has been described above. Note that various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure.

[0035] For example, instead of the grooves 61 and small grooves 63 described in the third embodiment, it is also possible to adopt a configuration including the protrusions 62 and small protrusions 64 described in the second embodiment. Here, the small protrusions 64 are members that protrude from the main surface 51a of the disk portion 51 in the direction of the axis Am and are arranged at intervals in the circumferential direction. The small protrusions 64 are formed integrally with the outer periphery of the protrusions 62. It is desirable that the number of small protrusions 64 be determined according to the same criteria as for the number of small grooves 63.

[0036] According to the above configuration, in addition to the protrusions 62, there are a plurality of small protrusions 64. This makes it possible to mistune vibration modes not only in the radial direction of the disk portion 51 but also in the circumferential direction. Therefore, it is possible to minimize the possibility of coupled vibrations and resonances that occur when various vibration modes are coupled together.

[0037] (Other Embodiments) Although the embodiments of the present disclosure have been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure.

[0038] For example, as a modified example common to all embodiments, the configuration shown in Fig. 8 can be adopted. In the example shown in Fig. 8, the grooves 61 or protrusions 62 of the detuning section 53 are not continuous annular but are divided into arcs, and a plurality of them are arranged at intervals in the circumferential direction. Note that it is also possible to combine a configuration in which the grooves 61 or protrusions 62 are divided in this way with the configuration having the small grooves 63 and small protrusions 64 described in the third embodiment above.

[0039] According to the above configuration, since a plurality of detuned portions 53 are arranged at intervals in the circumferential direction, it is possible to increase the rigidity in some circumferential regions where the detuned portions 53 are not provided. This increases the vibration frequency of the entire blisk blade 5 when excited. As a result, it is possible to optimize the vibration frequency, particularly in the low nodal diameter mode. Furthermore, since a plurality of detuned portions 53 are provided in the circumferential direction, it is also possible to create a mistuned state in the circumferential direction. This makes it possible to further reduce the possibility of coupled vibration and resonance.

[0040] Although not shown in the drawings, it is also possible to adopt a configuration in which a plurality of grooves 61 or protrusions 62 are arranged at intervals in the radial direction, as long as the minimum rigidity of the disk portion 51 can be ensured. With this configuration, the same effects as those described above can be obtained.

[0041] Furthermore, the small grooves 63 or small protrusions 64 described in the third embodiment may be provided on the inner circumferential side of the grooves 61 or protrusions 62, rather than on the outer circumferential side. It is also possible to provide the small grooves 63 or small protrusions 64 on both the inner and outer circumferential sides. In this case, the small grooves 63 or small protrusions 64 may be positioned at different circumferential positions on the inner and outer circumferential sides. This configuration allows for more precise control of the mistuned state.

[0042] <Additional Notes> The blisk blade 5 and the rotary machine described in each embodiment can be understood, for example, as follows.

[0043] (1) The blisk blade 5 according to the first aspect is a blisk blade 5 having a disk-shaped disk portion 51 centered on the axis Am and a plurality of blade portions 52 extending radially outward from the outer peripheral surface of the disk portion 51 and arranged in the circumferential direction, and a detuned portion 53 extending circumferentially around the axis Am is formed on a main surface 51 a of the disk portion 51 facing the axis Am.

[0044] According to the above configuration, the detuned portion 53 extending in the circumferential direction is provided on the main surface 51a of the disk portion 51. This changes the rigidity of the disk portion 51. By changing the rigidity in this way, it is possible to arbitrarily control the vibration frequency when the entire blisk blade 5 is excited.

[0045] (2) A blisk blade 5 according to a second aspect is the blisk blade 5 of (1), wherein the detuned portion 53 has a groove portion 61 recessed from the main surface 51 a toward the direction of the axis Am.

[0046] According to the above configuration, the detuned portion 53 has a groove portion 61 provided in the main surface 51a. The provision of this groove reduces the rigidity of the disk portion 51. As a result, the vibration frequency of the blisk blade 5 when excited decreases. This makes it possible to optimize the vibration characteristics in the low nodal diameter mode.

[0047] (3) A blisk blade 5 according to a third aspect is the blisk blade 5 of (2), wherein the detuning portion 53 further has a plurality of small groove portions 63 that are provided adjacent to the groove portion 61, are recessed from the main surface 51 a in the direction of the axis Am, and are arranged at intervals in the circumferential direction.

[0048] According to the above configuration, in addition to the groove 61, there are a plurality of small grooves 63. This makes it possible to mistune the vibration mode not only in the radial direction of the disk portion 51 but also in the circumferential direction.

[0049] (4) A blisk blade 5 according to a fourth aspect is the blisk blade 5 of (1), wherein the detuned portion 53 has a protrusion portion 62 that protrudes from the main surface 51 a in the direction of the axis Am.

[0050] According to the above configuration, the detuned portion 53 has a protrusion 62 provided on the main surface 51 a. The provision of this protrusion 62 increases the rigidity of the disk portion 51. As a result, the vibration frequency of the blisk blade 5 when excited also increases. This makes it possible to optimize the vibration characteristics in the low nodal diameter mode.

[0051] (5) A blisk blade 5 according to a fifth aspect is the blisk blade 5 of (4), wherein the detuning portion 53 further has a plurality of small protrusions 64 that are arranged adjacent to the protrusion 62, protrude from the main surface 51 a in the direction of the axis Am, and are arranged at intervals in the circumferential direction.

[0052] According to the above configuration, in addition to the protrusion 62, there are a plurality of small protrusions 64. This makes it possible to mistune the vibration mode not only in the radial direction of the disk portion 51 but also in the circumferential direction.

[0053] (6) A blisk blade 5 according to a sixth aspect is the blisk blade 5 according to any one of the aspects (1) to (5), wherein the detuned portion 53 has a circular ring shape that is continuous in the circumferential direction.

[0054] According to the above configuration, since the detuned portion 53 has a circular ring shape that is continuous in the circumferential direction, vibrations in the nodal diameter mode can be suppressed over the entire circumferential area.

[0055] (7) A blisk blade 5 according to a seventh aspect is the blisk blade 5 according to any one of the aspects (1) to (5), wherein the detuning portions 53 are arranged in a plurality at intervals in the circumferential direction.

[0056] According to the above configuration, since a plurality of detuned portions 53 are arranged at intervals in the circumferential direction, it is possible to increase the rigidity in a part of the circumferential region where the detuned portions 53 are not provided. This increases the vibration frequency of the entire blisk blade 5 when excited. As a result, it is possible to optimize the vibration frequency, particularly in the low nodal diameter mode.

[0057] (8) A rotary machine according to an eighth aspect includes the blisk blades 5 according to any one of the aspects (1) to (7), a rotating shaft that is rotatable around the axis Am and supports a plurality of the blisk blades 5, and a casing that covers the plurality of blisk blades 5 from the outer periphery.

[0058] According to the above configuration, coupled vibration and resonance of the blisk blades 5 are suppressed, and it is possible to provide a rotary machine that can be stably operated for a long period of time.

[0059] According to the present disclosure, it is possible to provide a blisk blade and a rotary machine in which vibration is further suppressed.

[0060] DESCRIPTION OF SYMBOLS 1...Compressor 2...Combustor 3...Turbine 5...Blisk blade 10...Intake duct 11...Compressor rotor 12...Compressor casing 13...Compressor rotor blade 14...Compressor rotor blade 15...Compressor stator blade 16...Compressor stator vane 21...Turbine rotor 22...Turbine casing 23...Turbine rotor blade 24...Turbine rotor blade 25...Turbine stator vane 26...Turbine stator vane 51...Disk portion 51a...Main surface 52...Blade portion 53...Detuning portion 61...Groove portion 62...Protrusion portion 63...Small groove portion 64...Small protrusion portion 91...Gas turbine rotor 92...Gas turbine casing 100...Aircraft gas turbine Am...Axis F...Fuel G...Combustion gas

Claims

1. A blisk blade having a circular disk portion centered on an axis, and a plurality of blade portions extending radially outward from the outer circumferential surface of the disk portion and arranged in a circumferential direction, wherein a detuned portion extending circumferentially around the axis is formed on the main surface of the disk portion facing the axial direction.

2. A blisk blade according to claim 1, wherein the detuned portion has a groove recessed from the main surface toward the axial direction.

3. A blisk blade as claimed in claim 2, wherein said detuning portion further comprises a plurality of small groove portions disposed adjacent to said groove portion, recessed from said main surface in the axial direction, and arranged at intervals in the circumferential direction.

4. A blisk blade according to claim 1, wherein the detuned portion has a protrusion protruding from the main surface in the axial direction.

5. A blisk blade as set forth in claim 4, wherein said detuning portion further comprises a plurality of small ridges arranged adjacent to said ridge, protruding from said main surface in the axial direction and arranged at intervals in the circumferential direction.

6. A blisk blade according to any one of claims 1 to 5, wherein the detuned portion has a circular ring shape that is continuous in the circumferential direction.

7. A blisk blade according to any one of claims 1 to 5, wherein the detuned portions are arranged in a plurality of positions spaced apart in the circumferential direction.

8. A rotary machine comprising: a blisk blade according to any one of claims 1 to 5; a rotating shaft rotatable about said axis and supporting a plurality of said blisk blades; and a casing covering said plurality of blisk blades from the outer periphery.

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