Wings and blisk wings

Abstract

To provide a blade with further reduced vibration, and a blisk blade.SOLUTION: A blade exposed to axially flowing working fluid, comprises: a blade body that radially extends with respect to an axial line and is circumferentially spaced apart, and in which a front edge side region located upstream and a rear edge side region located downstream are formed on a tip end surface, which is a radially outside end surface; and a shroud provided on the outer peripheral side of the blade body and covering any one of the front edge side region and the rear edge side region.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a blade and a blisk blade. [Background technology]

[0002] Turbopump turbines installed in space rocket engine systems have a wide operating speed range and high rotational speeds. In addition to this, they must be lightweight. Conventional methods for achieving this goal include not only thinning the walls of each component, but also eliminating shrouds at the blade tips, adopting a blisk structure in which the blades and disks are molded as a single unit, and shortening the axial distance between blade rows.

[0003] On the other hand, reducing the turbine's weight increases the resonant stress when resonance occurs due to the excitation force from adjacent blade rows, making the blades more susceptible to damage. Furthermore, the disk supporting the blades becomes thinner, making it easier for the blade vibration to couple with the disk vibration and form complex vibration modes. Furthermore, coupled flutter between the blade and disk becomes more likely to occur. For this reason, when reducing the turbine's weight, it is necessary to carry out a completely detuned design that separates the excitation frequency from the blade's natural frequency.

[0004] In a free-standing blade without a shroud, such as that shown in Patent Document 1, the blade is supported only from the inner periphery by a disk, and vibrations are likely to occur at the blade tip. Therefore, it is conceivable to provide an annular shroud on the outer periphery of the blade to connect the blades. In this case, the entire blade area from the leading edge to the trailing edge is generally covered by the shroud. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-227606 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the entire blade area from the leading edge to the trailing edge is covered with a shroud as described above, the weight increases by the amount of the shroud, which poses a problem of increasing the likelihood of vibration.

[0007] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a blade and a blisk blade in which vibration is further reduced. [Means for solving the problem]

[0008] In order to solve the above problems, the present disclosure Brisket Wing is a blade exposed to the working fluid flowing in the axial direction and a disk provided integrally on the radially inner side of the blade and having a disk shape centered on the axis line, a blade body extending in a radial direction relative to the axis and arranged at intervals in the circumferential direction, the blade body having a tip end face, which is an end face on the outer side in the radial direction, formed with a leading edge side region located on the upstream side and a trailing edge side region located on the downstream side; and a shroud provided on the outer circumferential side of the blade body and covering either the leading edge side region or the trailing edge side region. The shroud is integrally formed in a range of 30% to 70% of the blade length of the blade body in the axial direction with the trailing edge of the blade body as a reference. The blade according to the present disclosure is a blade exposed to a working fluid flowing in the axial direction, and comprises a blade body extending radially relative to the axis and arranged at intervals circumferentially, with a leading edge region located upstream and a trailing edge region located downstream at the tip end face, which is the radially outer end face, and a shroud provided on the outer periphery of the blade body and covering either the leading edge region or the trailing edge region, the shroud being formed integrally with the blade body over a range of 30% to 70% of the blade length in the axial direction, based on the trailing edge of the blade body, and the radial thickness of the shroud located between the blade bodies is set to be smaller than the radial thickness of the shroud where the blade body is located. The blade according to the present disclosure is a blade exposed to a working fluid flowing in the axial direction, and comprises a blade body extending radially relative to the axis and arranged at intervals circumferentially, with a leading edge region located upstream and a trailing edge region located downstream at the tip end face, which is the radially outer end face; and a shroud provided on the outer periphery of the blade body and covering either the leading edge region or the trailing edge region, wherein the radial thickness of the shroud between the blade bodies is set smaller than the radial thickness of the shroud where the blade body is located. The blade according to the present disclosure is a blade exposed to a working fluid flowing in the axial direction, and comprises a blade body extending radially relative to the axis and arranged at intervals circumferentially, with a leading edge region located upstream and a trailing edge region located downstream at the tip end face, which is the radially outer end face, and a shroud provided on the outer periphery of the blade body and covering either the leading edge region or the trailing edge region, wherein the radial thickness of the shroud between the blade bodies is set smaller than the radial thickness of the shroud where the blade body is located, and the radial thickness of the shroud on the trailing edge side becomes smaller as it goes downstream. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a blade and a blisk blade with further reduced vibration. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing the configuration of a rocket engine according to a first embodiment of the present disclosure. FIG. [Figure 2] FIG. 1 is a cross-sectional view showing a configuration of a turbine according to a first embodiment of the present disclosure. [Figure 3] FIG. 2 is a cross-sectional view of a blade according to the first embodiment of the present disclosure, viewed from the circumferential direction. [Figure 4]FIG. 2 is a view of a blade according to the first embodiment of the present disclosure as viewed from the radially outer side. [Figure 5] 1 is an interference diagram showing the relationship between nodal diameter number and vibration frequency in a blade. [Figure 6] FIG. 2 is a cross-sectional view showing a modified example of a blade according to the first embodiment of the present disclosure. [Figure 7] FIG. 10 is a view of a blade according to a second embodiment of the present disclosure as viewed from the radially outer side. [Figure 8] FIG. 10 is a diagram showing a first modified example of a blade according to a second embodiment of the present disclosure, as viewed from the radially outer side. [Figure 9] FIG. 10 is a view showing a second modified example of a blade according to a second embodiment of the present disclosure, as viewed from the radially outer side. [Figure 10] FIG. 10 is a cross-sectional view of a blade according to a third embodiment of the present disclosure, viewed from the axial direction. [Figure 11] FIG. 10 is a view of a first modified example of a blade according to a third embodiment of the present disclosure, viewed from the axial direction. [Figure 12] FIG. 10 is a cross-sectional view showing a second modified example of a blade according to a third embodiment of the present disclosure. [Figure 13] FIG. 10 is a cross-sectional view showing a third modified example of a blade according to a third embodiment of the present disclosure. [Figure 14] FIG. 10 is a cross-sectional view showing the configuration of an impeller according to a fourth embodiment of the present disclosure. [Figure 15] FIG. 10 is a cross-sectional view showing a modified example of an impeller according to the fourth embodiment of the present disclosure. [Figure 16] FIG. 10 is a cross-sectional view of a blade according to a fifth embodiment of the present disclosure, viewed from the circumferential direction. DETAILED DESCRIPTION OF THE INVENTION

[0011] First Embodiment (Rocket engine configuration) A rocket engine 100 and a wing according to a first embodiment of the present disclosure will be described below with reference to FIGS. 1 to 5. FIG.

[0012] As shown in FIG. 1, the rocket engine 100 includes a liquid hydrogen turbopump 1, a liquid oxygen turbopump 2, an engine body 3, a fuel line 4, an oxidizer line 5, a cooling line 6, a recovery line 7, a fuel valve 8, an oxidizer valve 9, and a coolant valve 10.

[0013] The liquid hydrogen turbopump 1 is a device for pumping liquid hydrogen as fuel to the engine body 3. The liquid hydrogen turbopump 1 has a pump body 11 and a turbine 12. The pump body 11 is driven to rotate by the rotational force generated by the turbine 12. The pump body 11 is connected to the engine body 3 by a fuel line 4. A fuel valve 8 is provided on the fuel line 4 to change the amount of liquid hydrogen supplied.

[0014] The pump body 11 is also connected to the engine body 3 by a cooling line 6 that branches off midway from the fuel line 4. In other words, the liquid hydrogen pumped to the pump body 11 is used not only as fuel but also as a coolant for the engine body 3. The engine body 3 has a combustion chamber 31 and a nozzle 32. Liquid hydrogen as fuel is sent to the combustion chamber 31 by the fuel line 4, and liquid hydrogen as a coolant is sent to the nozzle 32 by the cooling line 6. A coolant valve 10 is provided on the cooling line 6 to change the amount of liquid hydrogen supplied.

[0015] The liquid hydrogen used as a coolant to cool the nozzle 32 through the cooling line 6 is returned to the turbine 12 and provides rotational energy to the turbine 12, thereby driving the pump main body 11. The liquid hydrogen used to drive the pump main body 11 is sent to the turbine 22 of the liquid oxygen turbopump 2, which will be described later, through a recovery line 7 connected to the turbine 12. The liquid hydrogen used to drive the turbine 22 is released to the outside of the engine main body 3 through the nozzle 32.

[0016] The liquid oxygen turbo pump 2 is a device for pumping liquid oxygen as an oxidizer to the engine body 3 (combustion chamber 31). The liquid oxygen turbo pump 2 has a pump body 21 and a turbine 22. The pump body 21 is rotationally driven by the rotational force generated by the turbine 22. The pump body 21 is connected to the combustion chamber 31 of the engine body 3 by an oxidizer line 5. An oxidizer valve 9 is provided on the oxidizer line 5 to change the amount of oxidizer supplied.

[0017] (Turbine configuration) Next, the configurations of the turbine 12 and the turbine 22 will be described with reference to Figures 2 to 5. Since the turbine 12 and the turbine 22 have the same configuration, only the turbine 12 will be described below as a representative example.

[0018] As shown in Figure 2, the turbine 12 has a shaft 40 extending along the axis O, a pair of rotor blade rows 41 spaced apart from each other in the direction of the axis O on the shaft 40, a cylindrical casing 42 covering the shaft 40 and the rotor blade rows 41 from the radial outside, and a total of a pair of stator blade rows 43 provided on the inner surface of the casing 42, one on each upstream side of each rotor blade row 41 (one side in the direction of the axis O: the side where the fluid flows in).

[0019] The shaft 40 is rotatable around the axis O. The rotor blade row 41 is formed integrally with the shaft 40. That is, the shaft 40 and the rotor blade row 41 constitute a so-called blisk blade. The rotor blade row 41 is exposed to a working fluid flowing from one side (upstream side) to the other side (downstream side) along the axis O. Each rotor blade row 41 includes a disk 41a that protrudes radially outward from the outer circumferential surface of the shaft 40, a platform 41b attached to the outer circumferential surface of the disk 41a, and a plurality of rotor blades 41c (airfoils) that extend radially outward from the platform 41b. The plurality of rotor blades 41c are arranged at intervals in the circumferential direction. Each rotor blade 41c has an airfoil-shaped cross-sectional shape when viewed radially. Furthermore, the dimension (thickness) of the disk 41a in the direction of the axis O is smaller than the dimensions of the rotor blades 41c and the platform 41b.

[0020] The stator vane row 43 has a plurality of stator vanes 43a protruding radially inward from the inner circumferential surface of the casing 42, and stator vane shrouds 43b provided at the inner circumferential ends of the stator vanes 43a. The stator vanes 43a have an airfoil-shaped cross section when viewed radially. The stator vane shrouds 43b are plate-shaped members attached to the inner circumferential ends of the stator vanes 43a. The plurality of stator vane shrouds 43b are continuous in the circumferential direction, forming a ring shape centered on the axis O. One such stator vane row 43 is arranged upstream of each of the rotor blade rows 41.

[0021] (Configuration of rotor blades) As shown in Figures 3 and 4, the rotor blade 41c has a blade body 41d and a shroud 41e. As shown in Figure 4, the blade body 41d has an airfoil-shaped cross section extending from a leading edge 41f to a trailing edge 41g. As shown in Figure 3, the surface of the blade body 41d facing radially outward is a tip end surface 41j. The tip end surface 41j extends along the axis O.

[0022] The shroud 41e covers a portion of the tip end face 41j of the blade main body 41d from the radially outer side. The shroud 41e may be formed integrally with the blade main body 41d or separately. Forming the shroud 41e integrally facilitates machining by minimizing the dimension of the shroud 41e in the direction of the axis O. The shroud 41e extends continuously in the circumferential direction, forming an annular shape centered on the axis O. As shown in FIG. 4, when the region of the tip end face 41j including the leading edge 41f is defined as a leading-edge-side region A1 and the region of the tip end face 41j including the trailing edge 41g is defined as a trailing-edge-side region A2, the shroud 41e covers only the trailing-edge-side region A2. In other words, the leading-edge-side region A2 of the tip end face 41j is exposed radially outward.

[0023] The trailing edge side region A2 here refers to a region of 20% to 80% of the blade length (blade length) of the blade body 41d in the direction of the axis O, based on the trailing edge 41g. More preferably, the trailing edge side region A2 is a region of 30% to 70% of the blade length. Most preferably, the trailing edge side region A2 is a region of 40% to 60% of the blade length. Furthermore, as shown in FIG. 4, the shroud 41e covers the position (throat position S) where the distance between a pair of adjacent blade bodies 41d is narrowest. The throat position S is a position on a line connecting the end of the pressure surface 41h of the blade body 41d on the trailing edge 41g side and the suction surface 41i of the adjacent blade body 41d.

[0024] As shown in Fig. 3, the shroud 41e has a rectangular cross-sectional shape when viewed from the circumferential direction. This forms a step between the leading-edge-side region A1 of the tip end face 41j and the outer peripheral surface 41k of the shroud 41e. In other words, the outer peripheral surface 41k is located radially outward of the leading-edge-side region A1. Also, as shown in Fig. 4, in this embodiment, both the upstream-facing surface and the downstream-facing surface of the shroud 41e extend flat. Furthermore, the downstream-facing surface of the shroud 41e is located on a straight line connecting the trailing edges 41g of the blade bodies 41d.

[0025] (Action and effect) In a free-standing blade without a shroud 41e, the blade body 41d is supported only from the inner periphery by the disk 41a, which makes it easy for vibration to occur at the blade tip. Therefore, it is conceivable to provide an annular shroud on the outer periphery of the blade to connect the blades. In this case, it is common practice to cover the entire blade area from the leading edge to the trailing edge with the shroud.

[0026] However, if the entire blade body 41d is covered with a shroud from the leading edge 41f to the trailing edge 41g, the weight of the blade body 41d increases by the amount of the shroud, which increases the likelihood of vibration. Therefore, in this embodiment, as described above, the shroud 41e covers only the trailing edge region A2.

[0027] According to the above configuration, the weight of the shroud 41e itself can be reduced compared to, for example, a configuration in which the shroud 41e covers both the leading-edge region A1 and the trailing-edge region A2. As a result, compared to a free-standing blade, the provision of the shroud reduces vibration at the blade tip of the blade body 41d. In addition, the light weight of the shroud 41e itself makes it possible to avoid an increase in excitation force due to the shroud 41e.

[0028] Furthermore, by appropriately adjusting the dimensions and size of the shroud 41e, it is possible to control specific vibration modes. As shown in the interference diagram shown as an example in FIG. 5, by adjusting the dimensions and size of the shroud 41e, it is possible to change each vibration mode from low to high. In FIG. 5, the solid curve indicates the vibration mode when the shroud 41e according to this embodiment is applied, and the dashed curve indicates the vibration mode when the shroud 41e is not attached. The area surrounded by straight lines indicates the operating speed range. As shown in the figure, the intervals between vibration modes within the operating speed range are widened, which indicates that the rotational speed range in which operation without causing resonance is expanded, especially in the high-order range.

[0029] Here, the trailing edge region A2 of the blade body 41d is thinner than the leading edge region A1, and therefore vibration is particularly likely to occur. According to the above configuration, the trailing edge region A2, where vibration is likely to occur, is covered by the shroud, which further reduces the occurrence of vibration.

[0030] Furthermore, with the above configuration, the trailing edge side region A2 including the throat position S is covered by the shroud 41e, which prevents the working fluid from flowing radially outward at the throat position S (improving sealing performance). This further improves the performance of the rotor blade 41c.

[0031] In this embodiment, the shroud 41e covers a range of 20% to 80% of the blade length of the blade main body 41d in the direction of the axis O. This configuration minimizes the increase in weight due to the provision of the shroud 41e, while reducing the vibration of the blade main body 41d.

[0032] The first embodiment of the present disclosure has been described above. Various changes and modifications can be made to the above configuration without departing from the spirit and scope of the present disclosure. For example, as shown in FIG. 6, a modified example can be configured such that the outer circumferential surface 41k of the shroud 41e is flush with the tip end surface 41j. In other words, in this case, the shroud 41e is housed in a notch formed in the blade main body 41d. With this configuration, the tip end surface 41j of the blade main body 41d and the outer circumferential surface 41k of the shroud 41e are flush with each other, so no step is formed between the casing 42 and the rotor blade 41c. This further reduces leakage flow between the casing 42 and the rotor blade 41c.

[0033] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to FIG. 7. 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. As shown in FIG. 7, in this embodiment, the shape of the shroud 41e is different from that of the first embodiment. In the shroud 41e according to this embodiment, the downstream surface 41n, which is the surface facing the downstream side, is aligned circumferentially in the direction of the axis O, while the upstream surface 41l, which is the surface facing the upstream side, is wavy.

[0034] Specifically, the upstream surface 41l is formed with a plurality of recesses 41m recessed toward the downstream side. Each recess 41m is formed between adjacent blade bodies 41d. That is, the length of the shroud 41e in the direction of the axis O between the blade bodies 41d is set to be shorter than the length of the shroud 41e in the direction of the axis O where the blade bodies 41d are located.

[0035] According to the above configuration, the axial length of the portion of the shroud located between the blade bodies is shorter than that of the other portions, which allows for further weight reduction of the shroud. Furthermore, by appropriately adjusting the size of the recess 41m, it becomes possible to control a specific vibration mode. This allows for further increased freedom in designing the rotor blade 41c.

[0036] The second embodiment of the present disclosure has been described above. Various changes and modifications can be made to the above configuration without departing from the spirit and scope of the present disclosure. For example, as shown in FIG. 8 as a first modified example, it is possible to form multiple recesses 41o recessed toward the upstream side on the downstream surface 41n, rather than on the upstream surface 41l. Furthermore, as shown in FIG. 9 as a second modified example, it is also possible to form recesses 41m on the upstream surface 41l and recesses 41o on the downstream surface 41n. These configurations also enable a reduction in the weight of the shroud 41e. Furthermore, it is possible to further increase the degree of freedom in design for vibration mode control.

[0037] As explained as a modification of the first embodiment, the shroud 41e according to this embodiment can also be configured so that the tip end face 41j and the outer circumferential surface of the shroud 41e are flush with each other.

[0038] Third Embodiment Next, a third embodiment of the present disclosure will be described with reference to FIG. 10 . Note that the same reference numerals are used to designate the same components as those in the above-described embodiments, and detailed description thereof will be omitted. As shown in FIG. 10 , in this embodiment, the thickness (radial dimension) of the shroud 41e is different between the portion where the blade main body 41d is located and the portion located between the blade main bodies 41d. Specifically, the thickness of the portion 41p located between the blade main bodies 41d is smaller than the thickness of the portion of the shroud 41e where the blade main body 41d is located. It is also desirable that the thickness of the shroud 41e gradually decreases as it moves away from the portion where the blade main body 41d is located (i.e., as it approaches the portion 41p). Note that in the example of FIG. 10 , the thickness is changed by forming recesses on the outer peripheral surface of the shroud 41e. However, as shown in FIG. 11 , similar recesses may also be formed on the inner peripheral surface. Furthermore, recesses may be formed on both the outer peripheral surface and the inner peripheral surface.

[0039] According to the above configuration, it is possible to further reduce the weight of the shroud 41e. Also, by appropriately adjusting the dimensions and size of the shroud 41e, it is possible to more precisely control a specific vibration mode.

[0040] The third embodiment of the present disclosure has been described above. Various changes and modifications can be made to the above configuration without departing from the spirit and scope of the present disclosure. For example, the configuration according to the second embodiment and the configuration according to the third embodiment can be combined and applied. As a second modified example, as shown in FIG. 12 , the shroud 41e can be configured so that its thickness decreases toward the upstream side (leading edge side). In this case, the thickness on the upstream side (leading edge side) can be decreased throughout the entire circumferential direction, or, as in the third embodiment, the thickness on the upstream side (leading edge side) can be decreased only in the portion between the blade bodies 41d. As a third modified example, as shown in FIG. 13 , the thickness can be decreased toward the downstream side (trailing edge side). Alternatively, the thickness on the upstream and downstream sides can be smaller than the thickness in the central portion. Either configuration enables both weight reduction of the shroud 41e and precise control of the vibration mode.

[0041] <Fourth embodiment> Next, a fourth embodiment of the present disclosure will be described with reference to Fig. 14. As shown in Fig. 14, in this embodiment, a shroud 203 is applied to an impeller 200 that is applied to a compressor or a pump.

[0042] The impeller 200 includes a cylindrical disk 201 centered on an axis O2, a plurality of blades 202 (vanes) extending from the outer peripheral surface (main surface 201a) of the disk 201 toward the outer peripheral side, and a shroud 203 covering the outer peripheral surfaces of the plurality of blades 202 from the outside. The main surface 201a of the disk 201 is curved radially outward from one side along the axis O2 (i.e., the side from which the fluid flows: upstream side) to the other side (the side from which the fluid flows away: downstream side). The blades 202 are arranged circumferentially on the main surface 201a at intervals. Each blade 202 has a leading edge 202b facing upstream and a trailing edge 202c facing downstream. Although not shown in detail, each blade 202 is twisted from one circumferential side to the other circumferential side as it moves from the leading edge 202b side to the trailing edge 202c side.

[0043] Of the surface of the blade 202 facing the outer periphery (blade outer periphery surface 202a), the portion on the leading edge 202b side is defined as a leading-edge-side region A1, and the portion on the trailing edge 202c side is defined as a trailing-edge-side region A2. As in the first embodiment, the trailing-edge-side region A2 here refers to a region that is 20% to 80% of the length of the blade 202 in the direction of the axis O2, based on the trailing edge 202c. Desirably, the trailing-edge-side region A2 is a region that is 30% to 70% of the length of the blade 202. Most desirably, the trailing-edge-side region A2 is a region that is 40% to 60% of the length of the blade 202.

[0044] The shroud 203 covers only a portion (trailing edge region A2) of the blade outer peripheral surface 202a, including the edge on the trailing edge 202c side, from the outer peripheral side. In other words, the leading edge region A1 of the blade outer peripheral surface 202a is exposed radially outward. In this embodiment, a step is formed between the leading edge region A1 and the outer peripheral surface 203a of the shroud 203.

[0045] According to the above configuration, vibrations occurring in the blades 202 can be reduced by the shroud 203. Also, weight increase can be suppressed compared to when the shroud 203 is provided over the entire area of ​​the blades 202 in the direction of the axis O2. This allows compressors and pumps equipped with the impeller 200 to operate more stably.

[0046] The fourth embodiment of the present disclosure has been described above. Various changes and modifications can be made to the above configuration without departing from the spirit and scope of the present disclosure. For example, as shown in a modified example in FIG. 15 , the outer circumferential surface 203 a of the shroud 203 can be configured to be flush with the outer circumferential surface 202 a of the blade in the leading edge region A1.

[0047] Furthermore, it is also possible to apply the configurations according to the second and third embodiments and their modifications to the shroud 203 according to this embodiment in combination.

[0048] Furthermore, as a modification common to all the embodiments, the configuration shown in Fig. 16 can be employed. In the above-described embodiments, an example has been described in which the shroud 41e (or the shroud 203) covers the trailing edge side region A2. However, as shown in Fig. 16, it is also possible to employ a configuration in which the shroud 41e covers the leading edge side region A1. In other words, it is sufficient that the shroud 41e covers either the leading edge side region A1 or the trailing edge side region A2.

[0049] <Additional Notes> The blades (moving blade 41c, blade 202) and blisk blades described in each embodiment can be understood, for example, as follows.

[0050] (1) The blade according to the first aspect is a blade exposed to a working fluid flowing in the direction of an axis O, and includes a blade body 41d extending radially relative to the axis O and arranged at intervals in the circumferential direction, the blade body 41d having a tip end face 41j, which is the radially outer end face, on which a leading edge region A1 located upstream and a trailing edge region A2 located downstream are formed, and a shroud 41e provided on the outer periphery of the blade body 41d and covering either the leading edge region A1 or the trailing edge region A2.

[0051] According to the above configuration, the shroud 41e covers only one of the leading-edge region A1 and the trailing-edge region A2. This allows the weight of the shroud 41e itself to be reduced compared to, for example, a configuration in which the shroud 41e covers both the leading-edge region A1 and the trailing-edge region A2. As a result, compared to a free-standing blade, the provision of the shroud 41e reduces the vibration of the blade body 41d. In addition, the lightweight shroud 41e itself prevents an increase in excitation force due to the shroud 41e. Furthermore, by appropriately adjusting the dimensions and size of the shroud 41e, it becomes possible to control a specific vibration mode.

[0052] (2) In the blade according to the second aspect, the shroud 41e covers the trailing edge side region A2, and the leading edge side region A1 is exposed radially outward.

[0053] Here, the trailing edge region A2 of the blade body 41d is thinner than the leading edge region A1, and therefore vibration is particularly likely to occur. With the above configuration, the trailing edge region A2, where vibration is likely to occur, is covered by the shroud 41e, which further actively reduces the occurrence of vibration.

[0054] (3) In the blade according to the third aspect, either one of the leading-edge-side region A1 and the trailing-edge-side region A2 is flush with the outer circumferential surface of the shroud 41e.

[0055] According to the above configuration, the tip end surface 41j of the blade body 41d and the outer peripheral surface of the shroud 41e are flush with each other, so that no step is formed between the casing and the blade, thereby reducing leakage flow occurring between the casing and the blade.

[0056] (4) In the blade according to the fourth aspect, the trailing edge region A2 includes a throat position S where the distance between the pair of adjacent blade bodies 41d is smallest.

[0057] According to the above configuration, the trailing edge side region A2 including the throat position S is covered by the shroud 41e, so that it is possible to prevent the working fluid from flowing radially outward at the throat position S (it is possible to improve sealing performance), thereby further improving the performance of the blade.

[0058] (5) In the blade according to the fifth aspect, the shroud 41e covers a range of 20% to 80% of the blade length of the blade main body 41d in the direction of the axis O.

[0059] According to the above configuration, it is possible to reduce the vibration of the blade main body 41d while minimizing the weight increase due to the provision of the shroud 41e. In addition, by appropriately adjusting the dimensions and size of the shroud 41e, it is possible to control a specific vibration mode.

[0060] (6) In the blade of the sixth aspect, the length of the portion of the shroud 41e located between the blade main bodies 41d in the direction of the axis O is set to be smaller than the length of the portion of the shroud 41e in the direction of the axis O where the blade main bodies 41d are located.

[0061] According to the above configuration, the length of the portion of the shroud 41e located between the blade bodies 41d in the direction of the axis O is smaller than that of the other portions, and therefore the weight of the shroud 41e can be further reduced.

[0062] (7) In the blade according to the seventh aspect, the upstream end surface of the shroud 41e is recessed downstream in a portion located between the blade bodies 41d.

[0063] According to the above configuration, it is possible to further reduce the weight of the shroud 41e. Also, by appropriately adjusting the dimensions and size of the shroud 41e, it is possible to control a specific vibration mode.

[0064] (8) In the blade according to the eighth aspect, the downstream end surface of the shroud 41e is recessed toward the upstream side in a portion located between the blade bodies 41d.

[0065] According to the above configuration, it is possible to further reduce the weight of the shroud 41e. Also, by appropriately adjusting the dimensions and size of the shroud 41e, it is possible to control a specific vibration mode.

[0066] (9) In the blade of the ninth aspect, the radial thickness of the portion of the shroud 41e located between the blade main bodies 41d is set to be smaller than the radial thickness of the portion of the shroud 41e where the blade main bodies 41d are located.

[0067] According to the above configuration, it is possible to further reduce the weight of the shroud 41e. Also, by appropriately adjusting the dimensions and size of the shroud 41e, it is possible to control a specific vibration mode.

[0068] (10) In the blade according to the tenth aspect, the radial thickness of the shroud 41e on the leading edge side becomes smaller toward the upstream side.

[0069] According to the above configuration, it is possible to further reduce the weight of the shroud 41e. Also, by appropriately adjusting the dimensions and size of the shroud 41e, it is possible to control a specific vibration mode.

[0070] (11) In the blade according to the eleventh aspect, the radial thickness of the shroud 41e on the trailing edge side becomes smaller toward the downstream side.

[0071] According to the above configuration, it is possible to further reduce the weight of the shroud 41e. Also, by appropriately adjusting the dimensions and size of the shroud 41e, it is possible to control a specific vibration mode.

[0072] (12) A blisk blade (row of rotor blades 41) according to a twelfth aspect includes a blade according to any one of the above aspects and a disk 41a integrally formed radially inside the blade and having a disk shape centered on the axis.

[0073] According to the above configuration, it is possible to obtain a blisk blade that has reduced vibration and is lightweight. [Explanation of symbols]

[0074] 100 rocket engines 1 Liquid hydrogen turbopump 2 Liquid oxygen turbopump 3 Engine body 4 fuel lines 5. Oxidizer Line 6 Cooling Line 7. Collection Line 8 Fuel Valve 9 Oxidizer Valve 10 Coolant Valve 11,21 Pump body 12,22 Turbine 31 Combustion chamber 32 nozzles 40 shaft 41 Moving blade row 41a Disc 41b Platform 41c Moving blade (wing) 41d Wing body 41e Shroud 41f leading edge 41g trailing edge 41h ventral surface 41i back 41j Chip end face 41k outer surface 41l Upstream face 41m recess 41n downstream surface 41o recess 41p part 200 impeller 201 Disc 201a Main surface 202 Blade (Wing) 202a Blade outer surface 202b leading edge 202c trailing edge 203 Shroud 203a Outer surface A1 Leading edge area A2 Posterior edge area O,O2 axis S throat position

Claims

1. a blade exposed to a working fluid flowing in an axial direction; a disk provided integrally with the blade radially inside and centered on the axis; A blisk blade comprising: a blade body extending in a radial direction relative to the axis and arranged at intervals in a circumferential direction, the blade body having a tip end surface, which is an end surface on the outer side in the radial direction, formed with a leading edge region located upstream and a trailing edge region located downstream; a shroud provided on an outer circumferential side of the blade body and covering either the leading edge side region or the trailing edge side region; Equipped with The shroud is a blisk blade integrally formed in a range of 30% to 70% of the blade length of the blade body in the axial direction based on the trailing edge of the blade body.

2. The blisk blade according to claim 1, wherein the shroud is integrally formed in a range of 40% to 60% of the blade length of the blade body in the axial direction based on the trailing edge of the blade body.

3. The blisk vane according to claim 1 , wherein the shroud covers the trailing edge region and the leading edge region is exposed radially outward.

4. The blisk blade according to claim 1 , wherein one of the leading edge side region and the trailing edge side region is flush with an outer circumferential surface of the shroud.

5. The blisk blade according to claim 1 , wherein the trailing edge side region includes a throat position where a distance between a pair of adjacent blade bodies is smallest.

6. 6. The blisk vane according to claim 1, wherein a length in the axial direction of a portion of the shroud located between the blade bodies is set to be smaller than a length in the axial direction of a portion of the shroud where the blade bodies are located.

7. The blisk blade according to claim 6 , wherein an end surface of the shroud facing the upstream side is recessed toward the downstream side in a portion located between the blade bodies.

8. 8. The blisk blade according to claim 6, wherein an end surface of the shroud facing the downstream side is recessed toward the upstream side in a portion located between the blade bodies.

9. The blisk vane according to any one of claims 1 to 8, wherein a radial thickness of the shroud on a leading edge side becomes smaller toward an upstream side.

10. A blade exposed to a working fluid flowing in an axial direction, a blade body extending in a radial direction relative to the axis and arranged at intervals in a circumferential direction, the blade body having a tip end surface, which is an end surface on the outer side in the radial direction, formed with a leading edge region located upstream and a trailing edge region located downstream; a shroud provided on an outer circumferential side of the blade body and covering either the leading edge side region or the trailing edge side region; Equipped with The shroud is integrally formed in a range of 30% to 70% of the blade length of the blade body in the axial direction based on the trailing edge of the blade body, A blade in which the radial thickness of a portion of the shroud located between the blade bodies is set smaller than the radial thickness of a portion of the shroud where the blade bodies are located.

11. A blade exposed to a working fluid flowing in an axial direction, a blade body extending in a radial direction relative to the axis and arranged at intervals in a circumferential direction, the blade body having a tip end surface, which is an end surface on the outer side in the radial direction, formed with a leading edge region located upstream and a trailing edge region located downstream; a shroud provided on an outer circumferential side of the blade body and covering either the leading edge side region or the trailing edge side region; Equipped with A blade in which the radial thickness of a portion of the shroud located between the blade bodies is set smaller than the radial thickness of a portion of the shroud where the blade bodies are located.

12. A blade exposed to a working fluid flowing in an axial direction, a blade body extending in a radial direction relative to the axis and arranged at intervals in a circumferential direction, the blade body having a tip end surface, which is an end surface on the outer side in the radial direction, formed with a leading edge region located upstream and a trailing edge region located downstream; a shroud provided on an outer circumferential side of the blade body and covering either the leading edge side region or the trailing edge side region; Equipped with A blade in which the radial thickness of the shroud at a portion located between the blade bodies is set smaller than the radial thickness of the shroud at a portion where the blade bodies are located, and the radial thickness of the shroud at a trailing edge side becomes smaller toward the downstream side.

13. A blade according to any one of claims 10 to 12; a disk provided integrally with the blade radially inside and centered on the axis; Blisk wing with.

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