WO2023112584A1 - Rotary body, device and facility provided with same, method for manufacturing rotary body, and method for preventing noise of rotary body - Google Patents

Abstract

In this rotary body, a hole that is opened in a surface of the rotary body is formed. If noise ascribable to the hole is generated when the rotary body is rotated, the depth of the hole or the inner diameter of the hole is changed so that an acoustic natural frequency determined by the inner diameter of the hole and the depth of the hole is offset from a vortex shedding frequency determined by the circumferential speed of the hole opening at a predetermined number of revolutions.

Description

Rotating body, device and equipment provided with the same, method for manufacturing rotating body, method for preventing noise of rotating body

TECHNICAL FIELD The present disclosure relates to a rotating body, an apparatus and equipment including the same, a method for manufacturing the rotating body, and a method for preventing noise of the rotating body.
This application claims priority based on Japanese Patent Application No. 2021-204323 filed in Japan on December 16, 2021, the content of which is incorporated herein.

A rotating body that rotates about its axis may have a hole recessed from the surface of the rotating body. In such a rotating body, noise may be generated due to the holes as the rotating body rotates.

Patent Document 1 below discloses a lock nut as an example of a rotating body that rotates about its axis. The lock nut is formed with a rotational balance adjustment hole recessed in the axial direction from the surface thereof. The opening of this rotational balance adjustment hole is closed by a screw plug that is screwed into this adjustment hole. Therefore, with the technique described in Patent Document 1, even if the lock nut rotates, noise caused by the rotation balance adjustment hole can be suppressed.

JP 2009-281426 A

Among the holes formed in the rotating body, there are holes that are not used permanently and holes that are not used for a long period of time, but there are also holes that are used frequently. For holes that will not be used permanently or holes that will not be used for a long period of time, in order to suppress noise caused by the holes, the openings of the holes are plugged with plugs or the like, as in the technique described in Patent Document 1 above. Blocking is effective. On the other hand, if the opening of a frequently used hole is closed with a plug or the like as in the technique described in Patent Document 1, the trouble of removing the plug or the like every time the hole is used increases. Further, when the hole is recessed in the radial direction with respect to the axis from the outer peripheral surface of the rotating body, there is a possibility that the plug or the like closing the opening of the hole may come off the rotating body due to the centrifugal force generated by the rotation of the rotating body.

Therefore, an object of the present disclosure is to provide a technology capable of suppressing the trouble of using the holes while suppressing the noise caused by the holes.

A rotating body as one aspect for achieving the above object,
A rotating body rotatable about an axis at a predetermined number of revolutions has a hole opening on the surface of the rotating body, and the acoustic natural frequency determined by the inner diameter of the hole and the depth of the hole is It deviates from the vortex generation frequency determined by the peripheral speed of the opening of the hole at the time of the predetermined rotation speed.

The inventor focused on the fact that when the rotating body rotates, a vortex is generated near the opening of the hole. The inventor believes that when the acoustic natural frequency of the hole is close to the vortex generation frequency of the vortex generated around the opening of the hole, self-excited noise is generated due to the hole, and the acoustic natural frequency deviates from the vortex generation frequency. It was found that the self-excited noise caused by the hole can be suppressed by Therefore, in this aspect, the self-excited noise caused by the holes can be suppressed.

A coupling device as one aspect for achieving the above object,
A spacer, which is a rotating body as the aspect, is rotatable about the axis at the predetermined number of rotations, and is arranged on the first side of the axis, which is one side in the axial direction in which the axis extends with respect to the spacer. and a second coupling that is rotatable about the axis at the predetermined number of rotations and that is arranged on the second side of the axis, which is the other side in the axial direction with respect to the spacer. a connector for interconnecting the first coupling flange, the spacer and the second coupling flange such that the flange, the first coupling flange, the spacer and the second coupling flange are rotatable together; And prepare.

In this aspect, it is possible to suppress the generation of self-excited noise caused by the spacer hole when the first coupling flange, spacer, and second coupling flange rotate together.

Coupling equipment as one aspect for achieving the above object,
and a coupling soundproof chamber that is fixed to a device installation surface on which the coupling device is arranged, is separated from the coupling device, and covers the coupling device. The walls forming the coupling soundproof chamber have sound absorbing material.

In this aspect, the coupling soundproof room can suppress the sound leaking out of the coupling soundproof room.

As one aspect for achieving the above object, a rotating machine equipment includes:
A rotary machine having a coupling device as the aspect, a rotor rotatable about the axis at the predetermined number of revolutions, and a casing that partially covers the rotor, and an enclosure that covers at least the casing of the rotary machine. And prepare. The rotor has a rotor shaft extending in the axial direction around the axis, and a functional member that is fixed to the outer periphery of the rotor shaft and rotates integrally with the rotor shaft to perform functions required of the rotating machine. and said first coupling flange secured to said axial end of said rotor shaft. The casing covers the functional part without covering the first coupling flange. The axis extends in directions including the horizontal direction. The enclosure has an upper coupling noise wall spaced upwardly from the coupling device and a pair of side coupling noise walls spaced laterally from the coupling device perpendicular to the axis. A first side coupling soundproof wall, which is one of the pair of side coupling soundproof walls, is arranged on the first lateral side of the two sides in the lateral direction with respect to the coupling device. there is Of the pair of side coupling soundproof walls, the other second side coupling soundproof wall is arranged on the second side direction side with respect to the coupling device, out of both sides in the side direction. there is The upper coupling noise barrier and the pair of side coupling noise barriers are connected to each other. The upper coupling sound barrier and the pair of side coupling sound barriers have a sound absorbing material.

In this aspect, since the coupling device is covered with the enclosure of the rotating machine, it is possible to suppress the sound leaking from the coupling device to the outside.

A method for manufacturing a rotating body as one aspect for achieving the above object includes:
A manufacturing method for a rotating body that has a hole that opens on its surface and that rotates about an axis at a predetermined number of revolutions. In this manufacturing method, a design step of designing the rotating body having the hole, and an acoustic natural frequency determined by the inner diameter of the hole and the depth of the hole determined in the design step are the same as those of the hole at the predetermined number of revolutions. a determination step of determining whether or not there is a possibility that self-excited noise caused by the hole is generated depending on whether or not the vortex generation frequency is deviated from the vortex generation frequency determined by the peripheral speed of the opening; When it is determined that there is a possibility that self-excited noise caused by a hole is generated, a redesigning step of correcting the size of the hole determined in the designing step, and manufacturing the rotating body determined in the redesigning step. Execute the manufacturing process.

In the rotating body manufactured by the manufacturing method of this aspect, it is possible to suppress self-excited noise caused by the holes, similarly to the rotating body in the above aspect.

A rotating body noise prevention method as one aspect for achieving the above object includes:
A noise prevention method for a rotating body that has a hole that opens on its surface and rotates about an axis at a predetermined number of revolutions. This noise prevention method includes a determination step of determining whether or not self-excited noise caused by the hole is generated when the rotating body is rotated about the axis at the predetermined number of revolutions; and a hole remodeling step of increasing the depth of the hole or increasing the inner diameter of the hole when it is determined that the self-excited noise is generated in the step.

In the rotor whose hole is modified by the noise prevention method of this aspect, self-excited noise caused by the hole can be suppressed, similar to the rotor in the above aspect.

In one aspect of the present disclosure, it is possible to suppress the trouble of using the hole while suppressing the noise caused by the hole when the rotating body is rotated.

1 is a cross-sectional view of a coupling device prior to modification in one embodiment of the present disclosure; FIG. 4 is a flow chart showing a procedure for executing a noise prevention method in one embodiment according to the present disclosure; 1 is an explanatory diagram showing how self-excited noise is generated and a method for suppressing self-excited noise in an embodiment according to the present disclosure; FIG. FIG. 4 is a cross-sectional view of a modified coupling device in accordance with one embodiment of the present disclosure; 4 is a flow chart showing an execution procedure of a method for manufacturing a rotating body in one embodiment according to the present disclosure; 1 is a conceptual diagram showing a configuration of rotating machinery equipment in an embodiment according to the present disclosure; FIG. [0014] Fig. 4 is a perspective view of the rear of the enclosure and the generator in one embodiment of the present disclosure; FIG. 2 is a plan view of the rear of the enclosure and the generator in one embodiment of the present disclosure; FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8; FIG. 10 is a cross-sectional view taken along the line XX in FIG. 9; FIG. 4 is a cross-sectional view of a main part of a coupling cover in one embodiment according to the present disclosure; FIG. 5 is a cross-sectional view of a main part of a coupling cover in a modified example of the embodiment according to the present disclosure; 1 is a cross-sectional view of a coupling arrangement in one embodiment according to the present disclosure; FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 13; FIG.

Various embodiments and various modifications according to the present disclosure will be described below with reference to the drawings.

"Embodiment of Coupling Device"
An embodiment of a coupling device having a rotating body according to the present disclosure will be described with reference to FIGS. 1 to 5. FIG.

As shown in FIG. 1, the coupling device 10 of this embodiment includes a first coupling flange 20, a second coupling flange 30, a first coupling flange 20 and a second cup. It comprises a spacer 40 arranged between the ring flange 30 and a plurality of connectors 11 that connect them to each other so that they can rotate together. It should be noted that the coupling device 10 shown in FIG. 1 is a coupling device before execution of a noise prevention method, which will be described later.

The connector 11 in this embodiment has a bolt 12 and a nut 13 .

The first coupling flange 20, the second coupling flange 30, and the spacer 40 are all disc-shaped. When the first coupling flange 20, the second coupling flange 30, and the spacer 40 are connected to each other by the plurality of connecting tools 11, the center axis of the disk-shaped first coupling flange 20 and the disk-shaped The central axis of the second coupling flange 30 and the central axis of the disk-shaped spacer 40 are located on the same axis Ar. In this state, the first coupling flange 20, the second coupling flange 30, and the spacer 40 are rotatable about the axis Ar at a predetermined number of revolutions. The predetermined number of revolutions is, for example, a predetermined rated number of revolutions. Here, the direction in which the axis line Ar extends is defined as the axial direction Da, the radial direction with respect to the axis line Ar is defined as the radial direction Dr, and the circumferential direction with respect to the axis line Ar is defined as the circumferential direction Dc. Further, in the axial direction Da, the side on which the first coupling flange 20 is arranged with respect to the spacer 40 is the first side Da1 on the axis, and the side on which the second coupling flange 30 is arranged with respect to the spacer 40 is the axis second side Da2.

The connector 11 in this embodiment has a bolt 12 and a nut 13 .

The disc-shaped first coupling flange 20 includes an outer peripheral surface 21, a contact surface 22, a non-contact surface 23, a plurality of bolt holes 24, a plurality of jack holes 25, one or more balance holes 26, have The outer peripheral surface 21 is the outer peripheral surface of a disc centered on the axis Ar. The contact surface 22 is a surface that spreads from the axis Ar in the radial direction Dr, connects to the edge of the outer peripheral surface 21 on the second side Da2 of the axis, and faces the second side Da2 of the axis. The non-contact surface 23 is a surface that spreads from the axis Ar in the radial direction Dr, connects to the edge of the outer peripheral surface 21 on the axis first side Da1, and faces the axis first side Da1. The plurality of bolt holes 24 are arranged in the circumferential direction Dc around the axis Ar. The bolt hole 24 is a hole penetrating from the non-contact surface 23 to the contact surface 22 . The inner diameter of the bolt hole 24 is a dimension through which the bolt 12 of the connector 11 can be inserted. The plurality of jack holes 25 are arranged in the circumferential direction Dc around the axis Ar. The jack hole 25 is a hole penetrating from the non-contact surface 23 to the contact surface 22 . A female screw 25s is formed in the inner peripheral surface of the jack hole 25 at a portion on the second side Da2 of the axis line. One or more balance holes 26 are holes through from the non-contact surface 23 to the contact surface 22 . When the first coupling flange 20, the second coupling flange 30 and the spacer 40 are connected to each other, the edges of the jacking hole 25 and the balance hole 26 and the non-contact surface 23 are aligned with those of these holes 25 and 26. It becomes the openings 25o and 26o.

The outer diameter of the disk-shaped second coupling flange 30 is the same as the outer diameter of the disk-shaped first coupling flange 20 . This second coupling flange 30 has an outer peripheral surface 31 , a contact surface 32 , a non-contact surface 33 , a plurality of bolt holes 34 and a plurality of jack holes 35 . The outer peripheral surface 31 is the outer peripheral surface of a disc centered on the axis Ar. The contact surface 32 is a surface that spreads from the axis Ar in the radial direction Dr, connects to the edge of the outer peripheral surface 31 on the axis first side Da1, and faces the axis first side Da1. The non-contact surface 33 is a surface that spreads from the axis Ar in the radial direction Dr, connects to the edge of the outer peripheral surface 31 on the second side Da2 of the axis, and faces the second side Da2 of the axis. The plurality of bolt holes 34 are arranged in the circumferential direction Dc around the axis Ar. The bolt hole 34 is a hole penetrating from the non-contact surface 33 to the contact surface 32 . The inner diameter of the bolt hole 34 is the same as the inner diameter of the bolt hole 24 of the first coupling flange 20 so that the bolt 12 of the connector 11 can be inserted. The plurality of jack holes 35 are arranged in the circumferential direction Dc around the axis Ar. The jack hole 35 is a hole penetrating from the non-contact surface 33 to the contact surface 32 . A female screw 35s is formed in the inner peripheral surface of the jack hole 35 at the portion on the first side Da1 of the axis line. One or more balance holes 36 are holes through from the non-contact surface 33 to the contact surface 32 . When the first coupling flange 20, the second coupling flange 30 and the spacer 40 are interconnected, the edges of the jacking hole 35 and the balance hole 36 and the non-contact surface 33 are aligned with those of these holes 35 and 36. They become openings 35o and 36o.

The outer diameter of the disc-shaped spacer 40 is slightly larger than the outer diameter of the first coupling flange 20 and the outer diameter of the second coupling flange 30 . This spacer 40 has an outer peripheral surface 41 , a first contact surface 42 , a second contact surface 43 , a plurality of bolt holes 44 and lifting holes 46 . The outer peripheral surface 41 is the outer peripheral surface of a disc centered on the axis Ar. The first contact surface 42 is a surface that spreads from the axis Ar in the radial direction Dr, connects to the edge of the outer peripheral surface 41 on the axis first side Da1, and faces the axis first side Da1. This first contact surface 42 is in contact with the contact surface 22 of the first coupling flange 20 when the first coupling flange 20 , the second coupling flange 30 and the spacer 40 are interconnected. The second contact surface 43 is a surface that spreads from the axis Ar in the radial direction Dr, connects to the edge of the outer peripheral surface 41 on the second side Da2 of the axis, and faces the second side Da2 of the axis. This second contact surface 43 is in contact with the contact surface 32 of the second coupling flange 30 when the first coupling flange 20 , the second coupling flange 30 and the spacer 40 are interconnected. The plurality of bolt holes 44 are arranged in the circumferential direction Dc around the axis Ar. The bolt hole 44 is a hole penetrating from the first contact surface 42 to the second contact surface 43 . The inner diameter of the bolt hole 44 is a dimension through which the bolt 12 of the connector 11 can be inserted. The lifting hole 46 is a hole recessed in the radial direction Dr from the outer peripheral surface 41 . An edge between the lifting hole 46 and the outer peripheral surface 41 is an opening 46 o of the lifting hole 46 . A female screw is formed on the inner peripheral surface of the lifting hole 46 .

The jack hole 25 of the first coupling flange 20 and the jack hole 35 of the second coupling flange 30 are holes into which the jack bolts 51 can be inserted. The tip of the jack bolt 51 is formed with a male thread that can be screwed into the female threads 25 s and 35 s formed on the inner peripheral surfaces of the jack holes 25 and 35 . These jack holes 25 and 35 are used when the coupling device 10 is disassembled. Specifically, when disassembling the coupling device 10, the jack bolts 51 are inserted into the jack holes 25 and 35, and the jack holes 25 and 35 are inserted so that the tips of the jack bolts 51 protrude from the contact surfaces 22 and 32. The male threads of the jack bolt 51 are screwed into the screws 25s and 35s. As a result, the spacers 40 attached to the contact surfaces 22, 32 of the coupling flanges 20, 30 are removed.

The balance hole 26 of the first coupling flange 20 is a hole for balancing the rotation of rotating parts including the first coupling flange 20. Further, the balance hole 36 of the second coupling flange 30 is also a hole for achieving rotational balance of rotating parts including the second coupling flange 30 .

The lifting hole 46 of the spacer 40 is a hole into which the tip of the eyebolt 54 can be screwed. This lifting hole 46 is used when assembling or disassembling the coupling device 10 . Specifically, when assembling or disassembling the coupling device 10 , the tip of the eyebolt 54 is screwed into the lifting hole 46 , and the spacer 40 is hung at a predetermined position via the eyebolt 54 . As a result, when the coupling device 10 is assembled or disassembled, the position of the spacer 40 can be stabilized and the spacer 40 can be prevented from falling.

The rotating body according to the present invention is the spacer 40 among the components of the coupling device 10 described above. Note that the first coupling flange 20 and the second coupling flange 30 are also a type of rotating body.

Next, a noise prevention method for the coupling device 10 described above will be described.

As shown in the flowchart of FIG. 2, first, the coupling device 10 is rotated at a predetermined number of revolutions about the axis Ar, and it is determined whether or not noise is generated at the predetermined number of revolutions (determination step S1). ). In this determination step S1, it is determined whether self-excited noise caused by the hole formed in the coupling device 10 is generated especially when the coupling device 10 is rotated at a predetermined number of revolutions. Here, for example, when the rotation speed of the coupling device 10 approaches a predetermined rotation speed in the process of increasing the rotation speed of the coupling device 10, the sound from the coupling device 10 suddenly increases. , it is determined that self-excited noise is occurring. The self-excited noise will be explained later in detail.

When it is determined in the determination step S1 that noise has occurred, the hole is remodeled (hole remodeling step S2). The modification of the holes will be explained later in detail. This completes the noise prevention method according to the present embodiment.

Next, self-excited noise when the rotating body 1 is rotating will be described using FIG.

The inventor paid attention to the fact that a vortex 6 is generated near the opening 5 of the hole 3 when the rotating body 1 rotates, and found that the vortex 6 generates self-excited noise.

Here, when the speed of sound is C, the depth of the hole 3 is L, and the inner diameter of the hole 3 is D, the acoustic natural frequency fa of the hole 3 can be expressed by the following equation.
f a = (C/4)/(L+0.85×D/2)

Further, when the peripheral speed of the opening 5 of the hole 3 when the rotating body 1 is rotating at a predetermined number of revolutions is U, and the Strouhal number is St, the vortex generation frequency Fk can be expressed by the following equation. can.
Fk = St x (U/D)
The peripheral speed U of the opening 5 of the hole 3 is determined by the distance from the axis Ar to the opening 5 of the hole 3 (rotational radius of the opening 5) and the rotation speed of the rotating body 1.

In addition, the dimensionless flow velocity Vr is calculated by the following equation using the acoustic natural frequency fa, the peripheral velocity U of the opening 5 of the hole 3, and the inner diameter D of the hole 3 described above.
Vr=1/fa×U/D

Whether or not there is a possibility that self-excited noise due to holes is generated depends on the relationship between the acoustic natural frequency fa and the vortex generation frequency Fk, and whether or not the dimensionless flow velocity Vr exists within a predetermined range. conduct. From the relationship between the acoustic natural frequency fa and the vortex generation frequency Fk, the self-excited noise occurs when the acoustic natural frequency fa matches the vortex generation frequency Fk, or when the acoustic natural frequency fa is close to the vortex generation frequency Fk. Occur. Therefore, it is preferable that the acoustic natural frequency fa is separated from the vortex generation frequency Fk to some extent.

Therefore, in order to suppress the self-excited noise, in the hole remodeling step S2, the hole 3 is remodeled so that the acoustic natural frequency fa is somewhat separated from the vortex generation frequency Fk. Specifically, the inner diameter Dx of the hole 3b after modification is made larger than the inner diameter D of the hole 3 before modification so that the acoustic natural frequency fa is somewhat separated from the vortex generation frequency Fk. Alternatively, the depth Lx of the hole 3a after remodeling is made deeper than the depth L of the hole before remodeling so that the acoustic natural frequency fa is somewhat separated from the vortex generation frequency Fk. Further, the corner between the surface 2 of the rotating body 1 and the inner peripheral surface 4 of the hole 3 before modification is chamfered. As a result, the inner peripheral surface of the hole 3a after remodeling consists of a first inner peripheral surface 4a which is a part of the inner peripheral surface 4 before remodeling, an end of the first inner peripheral surface 4a and the surface 2 of the rotating body 1. and a second inner peripheral surface 4b connecting the . The inner diameter of the second inner peripheral surface 4b gradually increases from the connection position with the first inner peripheral surface 4a toward the connection position with the surface 2 (opening 5a after remodeling). By chamfering the corner between the surface 2 of the rotating body 1 and the inner peripheral surface 4 of the hole 3 in this way, the power of the vortex generated due to the hole 3 can be reduced.

In the hole remodeling step S2 of this embodiment, the following remodeling is performed on the hole based on the above.

The coupling device 10 of this embodiment has a plurality of types of holes that are open on the surface. Therefore, in the determination step S1 described above, it is unclear which hole is generating the self-excited noise. Therefore, the following modifications are made to the plurality of types of holes in the coupling device 10 of the present embodiment.

Regarding the lifting hole 46 of the spacer 40, as described above using FIG. . Alternatively, the depth L of the lifting hole 46 before modification is increased so that the acoustic natural frequency fa is somewhat separated from the vortex generation frequency Fk. Here, as shown in FIGS. 1 and 4, the depth Lx of the lifting hole 46a after modification is made deeper than the depth L of the lifting hole 46 before modification. As a result, self-excited noise caused by the lifting hole 46 can be suppressed.

Further, as shown in FIG. 4, the corners between the inner peripheral surface 47 of the lifting hole 46 before modification and the outer peripheral surface 41 of the spacer 40 are ground and chamfered. As a result, the inner peripheral surface of the lifting hole 46a after modification consists of a first inner peripheral surface 47a which is a part of the inner peripheral surface 47 before modification, an edge of the first inner peripheral surface 47a and an outer peripheral surface of the spacer 40. A second inner peripheral surface 47b connecting with 41 is formed. The inner diameter of the second inner peripheral surface 47b gradually increases from the connection position with the first inner peripheral surface 47a toward the connection position with the outer peripheral surface 41 (opening 46oa after remodeling). As a result, the power of the vortex generated due to the lifting hole 46 can be reduced.

Regarding the jack hole 25 and balance hole 26 of the first coupling flange 20 and the jack hole 35 and balance hole 36 of the second coupling flange 30, as shown in FIG. 26o, 35o and 36o are closed with lids. This cover can be attached to and detached from the modified holes 25a, 26a, 35a, 36a. For this reason, threaded plugs 52 and 53 having external threads formed on the outer periphery are used as lids here. Therefore, the remodeled holes 25a, 26a, 35a, 36a to which the threaded plugs 52, 53 are attached are provided with female threads 25sa, 26s, 35sa, 36s into which the male threads of the threaded plugs 52, 53 can be screwed. formed.

By modifying each hole of the coupling device 10 as described above, the noise of the modified coupling device 10a can be suppressed.

By the way, the lifting hole 46a of the spacer 40 is a hole that is used each time the equipment including the coupling device 10a is inspected. For this reason, if the opening 46oa of the lifting hole 46a is closed with a threaded plug or the like, the threaded plug must be removed every time the lifting hole 46a is used, that is, every time the equipment including the coupling device 10a is inspected. work to remove and attach the Further, since the lifting hole 46a is a hole that opens in the outer peripheral surface 41 of the spacer 40, if the opening 46oa of the lifting hole 46a is closed with a plug with a screw or the like, the rotation of the coupling device 10a will The resulting centrifugal force may disengage the threaded plug or the like from the spacer 40 . Therefore, in the present embodiment, the depth of the post-remodeling lifting hole 46a is reduced in order to suppress the noise caused by the pre-remodeling lifting hole 46 and to reduce the labor involved in using the post-remodeling lifting hole 46. deepen. Alternatively, the inner diameter of the lifting hole 46a after remodeling is increased. In addition, the depth of the modified lifting hole 46a may be made shallow or the inner diameter of the modified lifting hole 46a may be decreased so that the acoustic natural frequency fa is separated from the vortex generation frequency Fk to some extent. good.

On the other hand, the balance holes 26a and 36a are holes that are not used permanently. Therefore, even if the openings 26o, 36o of the balance holes 26a, 36a are closed with the threaded plugs 53, it is not necessary to remove the threaded plugs 53 each time the equipment including the coupling device 10a is inspected. Moreover, since the openings 26o, 36o of the balance holes 26a, 36a are formed in the non-contact surfaces 23, 33, the centrifugal force acting on the threaded plug 53 is displaced from the balance holes 26a, 36a. Acting in a direction perpendicular to the detachment direction, this threaded plug 53 is less likely to detach from the coupling flanges 20,30. Therefore, in this embodiment, the openings 26o, 36o of the balance holes 26a, 36a are closed with threaded plugs 53. As shown in FIG.

Also, even if the openings 25o and 35o of the jack holes 25a and 35a are closed with the threaded plugs 52, the centrifugal force acting on the threaded plugs 52 is not in the direction in which the threaded plugs 52 are removed from the jack holes 25a and 35a. Acting in a vertical direction, this threaded plug 52 is less likely to come off the coupling flanges 20,30. Therefore, in the present embodiment, the openings 25o and 35o of the jack holes 25a and 35a are closed with threaded plugs 52. As shown in FIG.

A method for preventing noise caused by holes by modifying various holes in the coupling device 10 has been described above. However, depending on the method of manufacturing the coupling device, it is possible to suppress the noise caused by the holes without modifying the holes.

Therefore, next, a method for manufacturing a coupling device including a rotating body will be described according to the flowchart shown in FIG.

First, a coupling device including a rotating body is designed (design process S10). In this design step S10, for example, the coupling device 10 described with reference to FIG. 1 is designed. Therefore, this coupling device 10 is a device before the holes are modified by the noise prevention method described above. It should be noted that the balance holes 26 and 36 are basically not designed at the end of the design process S10.

Next, it is determined whether or not there is a possibility that noise is generated due to the holes when the coupling device 10 is rotated at a predetermined number of revolutions (determination step S11). In this determination step S11, it is determined whether or not there is a possibility that self-excited noise due to the hole will be generated especially when the coupling device 10 is rotated at a predetermined number of revolutions.

Whether or not there is a possibility that the self-excited noise caused by the hole is generated is determined when the acoustic natural frequency fa of the hole designed in the design step S10, as described above, is is deviated from the vortex generation frequency Fk of . In addition, it is determined that self-excited noise may occur when the aforementioned non-dimensional flow velocity Vt is, for example, 2.7 or more and 5.5 or less, and the non-dimensional flow velocity Vt is less than 2.7. Or, when it is greater than 5.5, it is determined that the possibility of generating self-excited noise is low.

If it is determined in the determination step S11 that there is a possibility that noise will occur, the coupling device 10 is redesigned (redesign step S12). In this redesigning step S12, redesigning is performed as follows.

Regarding the lifting hole 46 of the spacer 40, the dimensionless flow velocity Vt is less than 2.7 or greater than 5.5 with respect to the inner diameter D of the lifting hole 46 before the redesign step S12. The inner diameter Dx of the rear lifting hole 46a is increased. Alternatively, the lifting hole 46a after the redesigning step S12 is adjusted so that the dimensionless flow velocity Vt is less than 2.7 or greater than 5.5 with respect to the depth L of the lifting hole 46 before the redesigning step S12. Increase the depth Lx.

Regarding the jack hole 25 of the first coupling flange 20 and the jack hole 35 of the second coupling flange 30, the openings 25o and 35o of the jack holes 25 and 35 before the redesigning step S12 correspond to the jack holes 25 and 35. It is redesigned so that it can be closed with a removable threaded plug 52. That is, female threads 25sa, 35sa are provided on the inner peripheral surfaces of the redesigned jack holes 25a, 35a.

The balance hole 26 of the first coupling flange 20 and the balance hole 36 of the second coupling flange 30 are basically not designed even at the end of this redesign process S12. However, in this redesign step S12, when these balance holes 26 and 36 are provided, the openings 26o and 36o of these balance holes 26 and 36 are replaced by threaded plugs 53 that can be attached to and removed from the balance holes 26 and 36. In order to be able to block it, specify it in the redesign drawing.

Next, the coupling device 10a redesigned in the redesign process S12 is manufactured (manufacturing process S13). In this manufacturing step S13, for example, the coupling device 10a described with reference to FIG. 4 is manufactured.

The coupling device 10a manufactured as described above has the same structure as the coupling device 10a after modifying the hole by the noise prevention method described above. Therefore, even with the coupling device 10a manufactured as described above, the noise of the coupling device 10a including the rotating body (spacer 40) can be suppressed as in the case of the coupling device 10a after the hole has been modified by the noise prevention method described above. can be done.

"Embodiment of Rotating Mechanical Equipment"
Embodiments of rotating machinery according to the present disclosure will be described with reference to FIGS. 6-11.

As shown in FIG. 6, the rotating machine equipment of this embodiment includes a steam turbine 60 as a rotating machine, an enclosure 70 covering the steam turbine 60, a generator 80 capable of generating electricity by rotation of the steam turbine 60, a coupling and a device 10b.

A steam turbine 60 as a rotary machine includes a turbine rotor 61 rotatable about an axis Ar, a turbine casing 65 covering a portion of the turbine rotor 61, a first bearing device 67a rotatably supporting the turbine rotor 61, and a second bearing device 67b. Here, the direction in which the axis Ar extends is defined as the axial direction Da, the radial direction Dr relative to the axis Ar is defined as the radial direction Dr, and the circumferential direction Dc relative to the axis Ar is defined as the circumferential direction Dc.

The turbine rotor 61 includes a turbine rotor shaft 62 extending in the axial direction Da around the axis Ar, a plurality of moving blades 63 provided on the outer circumference of the turbine rotor shaft 62, and a coupling flange 64 provided at the end of the axis second side Da2. The turbine casing 65 covers a portion of the turbine rotor 61 where the multiple moving blades 63 are provided. The multiple moving blades 63 receive the force of the steam ST that has flowed into the turbine casing 65 to rotate the turbine rotor shaft 62 on which the multiple moving blades 63 are provided. Therefore, the plurality of rotor blades 63 are functional members that perform functions required of the steam turbine 60 by integrally rotating with the turbine rotor shaft 62 .

The first bearing device 67a rotatably supports a portion of the turbine rotor 61 on the axial first side Da1 in the axial direction Da. The second bearing device 67b rotatably supports a portion of the turbine rotor 61 that is located on the second side Da2 of the axis relative to the rotor blades 63 and located on the first side Da1 of the axis relative to the coupling flange 64 . Both the first bearing device 67 a and the second bearing device 67 b have a bearing 68 and a bearing casing 69 covering the bearing 68 .

The generator 80 as a rotary machine is arranged on the second side Da2 of the axis in the axial direction Da with respect to the steam turbine 60 . The generator 80 includes a generator rotor 81 rotatable about an axis Ar, a generator casing 85 covering a part of the generator rotor 81, and a coil 86 attached to the inner surface of the generator casing 85. , has

The generator rotor 81 includes a generator rotor shaft 82 extending in the axial direction Da around the axis Ar, magnets 83 fixed to the outer circumference of the generator rotor shaft 82 , and the generator rotor shaft 82 extending in the axial direction Da. a coupling flange 84 provided at the end of the first side Da1 of the axis at . A coil 86 provided on the generator casing 85 and a magnet 83 provided on the generator rotor shaft 82 face each other in the radial direction Dr. The magnet 83 rotates integrally with the generator rotor shaft 82 to cause a coil 86 provided in the generator casing 85 to generate electric power. Therefore, the magnet 83 is a functional member that exhibits the functions required of the generator 80 by integrally rotating with the generator rotor shaft 82 . The generator casing 85 covers a portion of the generator rotor 81 where the magnets 83 are provided.

The coupling device 10b of this embodiment has the modified coupling device 10a described above. That is, the coupling device 10b of the present embodiment includes the first coupling flange 20, the second coupling flange 30, the spacer 40, and the plurality of connectors 11, as described with reference to FIG. Prepare. Here, the first coupling flange 20 is the coupling flange 64 of the steam turbine 60 . Also, the second coupling flange 30 is the coupling flange 84 of the generator 80 .

As described above, the coupling device 10b of the present embodiment includes the modified first coupling flange 20, the modified second coupling flange 30, and the modified spacer 40 shown in FIG. Therefore, it is possible to suppress the noise accompanying the rotation of these.

In addition to the function as the bearing 68, the second bearing device 67b may also function as a clutch. In this case, the rotor projecting from the second bearing device 67b to the second side Da2 of the axis is a separate member from the rotor projecting from the second bearing device 67b to the first side Da1 of the axis. However, in this embodiment, even in such a case, the entire rotor existing on the first side Da1 of the axis line is based on the spacer 40 of the coupling device 10b located on the second side Da2 of the axis line relative to the second bearing device 67b. is treated as the turbine rotor 61 .

The coupling device 10b of this embodiment further has a coupling cover 90 that covers the outer peripheral sides of the first coupling flange 20, the second coupling flange 30, and the spacer 40. The coupling cover 90 is separated from the first coupling flange 20, the spacer 40, and the second coupling flange 30 in the radial direction Dr with respect to the axis Ar, and is spaced apart from the outer periphery of the first coupling flange 20, the outer periphery of the spacer 40, and the second coupling flange 30. It is annular so as to cover the outer periphery of the two coupling flanges 30 .

As shown in FIG. 11, the coupling cover 90 includes a support member 91 having an annular shape centered on the axis Ar, and a sound absorbing portion 92 arranged on the outer peripheral side of the support member 91 and supported by the support member 91. have. The annular support member 91 is formed with a plurality of through holes penetrating from the inner peripheral side to the outer peripheral side. This support member 91 is, for example, expanded metal or punching metal.

The sound absorbing portion 92 of the coupling cover 90 has a plurality of sound absorbing members 93 arranged in a radial direction Dr with respect to the axis Ar, and a sound insulating plate 94 arranged between the plurality of sound absorbing members 93 . Each of the plurality of sound absorbing materials 93 forms an annular shape centering on the axis Ar. In this embodiment, the multiple sound absorbing materials 93 include a first sound absorbing material 93a, a second sound absorbing material 93b, a third sound absorbing material 93c, a fourth sound absorbing material 93d, and a fifth sound absorbing material 93e. Among the plurality of sound absorbing materials 93, the first sound absorbing material 93a is arranged on the innermost side. The first sound absorbing member 93a is in contact with the support member 91 and is supported by the support member 91. As shown in FIG. The second sound absorbing material 93b is arranged on the outer peripheral side of the first sound absorbing material 93a. The third sound absorbing material 93c is arranged on the outer peripheral side of the second sound absorbing material 93b. The fourth sound absorbing material 93d is arranged on the outer peripheral side of the third sound absorbing material 93c. The fifth sound absorbing material 93e is arranged on the outer peripheral side of the fourth sound absorbing material 93d. The first sound absorbing material 93a and the fifth sound absorbing material 93e are made of glass cloth, for example. The second sound absorbing material 93b, the third sound absorbing material 93c and the fourth sound absorbing material 93d are made of rock wool, for example. Note that the sound absorbing portion 92 may further include a sound insulating plate 94 disposed between the support member 91 and the sound absorbing member 93 disposed innermost in the radial direction Dr among the plurality of sound absorbing members 93. good.

The sound insulating plate 94 is arranged between the second sound absorbing material 93b and the third sound absorbing material 93c and between the third sound absorbing material 93c and the fourth sound absorbing material 93d. The sound insulating plate 94 is made of, for example, an iron plate.

As described above, the coupling device 10b of the present embodiment has the coupling cover 90 including a plurality of sound absorbing materials 93, so that sound leaking out of the coupling device 10b can be suppressed.

Also, the coupling cover 90 may further have an inner sound absorbing material 95 as shown in FIG. The inner sound absorbing member 95 is arranged between the support member 91 and the sound absorbing portion 92 in the radial direction Dr. The inner sound absorbing material 95 is made of glass cloth, for example. The inner sound absorbing material 95 may be made of rock wool. By arranging the inner sound absorbing member 95 between the support member 91 and the sound absorbing portion 92 in this way, the inner sound absorbing member 95 prevents the sound from the noise source from reaching the innermost sound insulating plate 94, thereby preventing the sound from the noise source. can absorb some of the sound from Therefore, by arranging the inner sound absorbing material 95, it is possible to effectively suppress the sound leaking out of the coupling device 10b.

As shown in FIGS. 6 and 7, the enclosure 70 has a front soundproof wall 71 arranged on the first side Da1 of the axis relative to the steam turbine 60, and a second side Da2 of the axis relative to the steam turbine 60. It has a pair of rear soundproof walls 73 , a pair of side soundproof walls 72 arranged in the lateral direction Ds of the steam turbine 60 , and an upper soundproof wall 74 . The pair of rear soundproof walls 73 are soundproof walls that are located at the same position in the axial direction Da and both face the axial direction Da. The second rear soundproof wall 73b of the pair of rear soundproof walls 73 is arranged at a position away from the first rear soundproof wall 73a of the pair of rear soundproof walls 73 in the second lateral direction Ds2. Both of the pair of side soundproof walls 72 are soundproof walls facing the side direction Ds. A first side soundproof wall 72a of the pair of side soundproof walls 72 is arranged on the side of the steam turbine 60 in the first lateral direction Ds1. The second side soundproof wall 72b of the pair of side soundproof walls 72 is arranged on the side of the steam turbine 60 in the second lateral direction Ds2. The end of the front soundproof wall 71 in the first side direction Ds1 is connected to the end of the first side soundproof wall 72a on the axis first side Da1. The end of the front soundproof wall 71 in the second side direction Ds2 is connected to the end of the axis line first side Da1 of the second side soundproof wall 72b. The end of the first rear soundproof wall 73a in the first side direction Ds1 is connected to the end of the axis line second side Da2 of the first side soundproof wall 72a. The end of the second rear soundproof wall 73b in the second lateral direction Ds2 is connected to the end of the second lateral soundproof wall 72b on the axial second side Da2. The upper end of the front soundproof wall 71, the upper end of the first rear soundproof wall 73a, the upper end of the second rear soundproof wall 73b, the upper end of the first side soundproof wall 72a, and the upper end of the second side soundproof wall 72b are all It is connected to the upper soundproof wall 74 .

7-10, the enclosure 70 further includes a post-shift soundproof wall 75, a pair of lead-in side soundproof walls 76, a pair of side coupling soundproof walls 77, and an upper coupling soundproof wall 78. and have 8 is a plan view of the rear part of the enclosure 70 and the generator 80. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. FIG. 10 is a cross-sectional view taken along line XX in FIG. 9. FIG.

A pair of side coupling soundproof walls 77 are soundproof walls facing the side direction Ds. Of the pair of side coupling soundproof walls 77, the first side coupling soundproof wall 77a is arranged on the first side direction Ds1 side of the coupling device 10b. The second side coupling soundproof wall 77b of the pair of side coupling soundproof walls 77 is arranged in the second side direction Ds2 of the coupling device 10b. The first side coupling soundproof wall 77a and the second side coupling soundproof wall 77b face each other in the lateral direction Ds. The end of the axis line second side Da2 of the first side coupling soundproof wall 77a is connected to the end of the first rear soundproof wall 73a on the lower side and in the second side direction Ds2. The end of the axis line second side Da2 of the second side coupling soundproof wall 77b is connected to the end of the second rear soundproof wall 73b on the lower side and in the first lateral direction Ds1.

A pair of lead-in side soundproof walls 76 are soundproof walls facing the side direction Ds. Of the pair of lead-in side soundproof walls 76, the first lead-in side soundproof wall 76a is arranged above the first side coupling soundproof wall 77a and on the first lateral direction Ds1 side. A second lead-in side soundproof wall 76b of the pair of lead-in side soundproof walls 76 is arranged above the second side coupling soundproof wall 77b and on the second side direction Ds2 side. The first lead-in side soundproof wall 76a and the second lead-in side soundproof wall 76b face each other in the lateral direction Ds. The distance between the first lead-in side soundproof wall 76a and the second lead-in side soundproof wall 76b in the lateral direction Ds is equal to the distance between the first side coupling soundproof wall 77a and the second side coupling soundproof wall 77b in the lateral direction Ds. is wider than the interval between The end of the first lead-in side soundproof wall 76a on the second side Da2 of the axis line is connected to the upper side of the first rear soundproof wall 73a and the end of the second side direction Ds2. The end of the second lead-in side soundproof wall 76b on the second side Da2 of the axis line is connected to the upper side of the second rear soundproof wall 73b and the end in the first side direction Ds1.

The upper coupling soundproof wall 78 is a soundproof wall facing up and down. The upper coupling soundproof wall 78 is arranged above the coupling device 10b. The end of the upper coupling soundproof wall 78 in the first side direction Ds1 is connected to the lower end of the first lead-in side soundproof wall 76a. The end of the upper coupling soundproof wall 78 in the second side direction Ds2 is connected to the lower end of the second lead-in side soundproof wall 76b. A portion of the upper coupling soundproof wall 78 in the second side direction Ds2 from the first lead-in side soundproof wall 76a is connected to the upper end of the first side coupling soundproof wall 77a. A portion of the upper coupling soundproof wall 78 in the first side direction Ds1 from the second lead-in side soundproof wall 76b is connected to the upper end of the second side coupling soundproof wall 77b. Of the edges on the axis second side Da2 of the upper coupling soundproof wall 78, an intermediate edge 78m between the first side coupling soundproof wall 77a and the second side coupling soundproof wall 77b in the lateral direction Ds is The intermediate edge 78m is shifted to the axis first side Da1 from the edge portion in the lateral direction Ds.

The post-shift soundproof wall 75 is a soundproof wall facing the axial direction Da. This post-shift soundproof wall 75 is between the first retraction side soundproof wall 76a and the second retraction side soundproof wall 76b in the lateral direction Ds, It is arranged on the axis first side Da1 side of the soundproof wall 76 b and the upper coupling soundproof wall 78 . Therefore, the post-shift soundproof wall 75 is shifted to the axis first side Da1 relative to the pair of rear soundproof walls 73 . The end of the post-shift soundproof wall 75 in the first side direction Ds1 is connected to the end of the first lead-in side soundproof wall 76a on the axis first side Da1. The end of the post-shift soundproof wall 75 in the second side direction Ds2 is connected to the end of the second lead-in side soundproof wall 76b on the axis first side Da1. The lower end of the post-shift soundproof wall 75 is connected to the end of the upper coupling soundproof wall 78 on the axis first side Da1.

Both the upper end of the post-shift soundproof wall 75 and the upper end of the pair of lead-in side soundproof walls 76 are connected to the upper soundproof wall 74 .

Each of the plurality of soundproof walls constituting the enclosure 70 described above has a substrate 79a having rigidity and a sound absorbing material 79b attached to this substrate 79a.

The end of the generator casing 85 on the first side Da1 of the axis line is between the first side coupling soundproof wall 77a and the second side coupling soundproof wall 77b in the axial direction Da, and the first rear soundproof wall 73a and the second rear soundproof wall 73b on the axis first side Da1 and the intermediate edge 78m of the upper coupling soundproof wall 78 on the axis second side Da2. Therefore, the end portion of the generator casing 85 on the first side Da1 of the axis line is arranged at a position retracted between the first side coupling soundproof wall 77a and the second side coupling soundproof wall 77b in the axial direction Da. It is

As described above, the coupling device 10b of the present embodiment is surrounded by the pair of the side coupling soundproof wall 77 and the upper coupling soundproof wall 78 of the enclosure 70, so that the leakage to the outside from the coupling device 10b You can suppress the sound that comes out.

In this embodiment, the coupling device 10b has a coupling cover 90, and the enclosure 70 has a pair of side coupling soundproof walls 77 covering the coupling device 10b and an upper coupling soundproof wall 78. . However, if the coupling device 10b has a coupling cover 90, the pair of side coupling soundproof walls 77 and the upper coupling soundproof wall 78 of the enclosure 70 may be omitted. Further, when the enclosure 70 has a pair of side coupling soundproof walls 77 and an upper coupling soundproof wall 78, the coupling cover 90 of the coupling device 10b may be omitted.

"Embodiment of Coupling Equipment"
An embodiment of a coupling arrangement according to the present disclosure will now be described with reference to FIGS. 13 and 14. FIG.

The coupling equipment 100 of the present embodiment is equipment that is applied when there is no enclosure 70 that covers the steam turbine 60 in the rotating machinery equipment described above. The coupling equipment 100 includes a coupling device 10b, a coupling soundproof chamber 101 covering the coupling device 10b, an intake channel frame 111, and an exhaust channel frame 121.

The coupling device 10b of this embodiment is the same as the coupling device 10b in the rotary machine equipment described above. Therefore, the coupling device 10b of this embodiment also has the first coupling flange 20, the second coupling flange 30, the spacer 40, and the plurality of connectors 11 shown in FIG. Furthermore, the coupling device 10b of this embodiment also has a coupling cover 90. As shown in FIG.

The coupling soundproof room 101 has a front coupling soundproof wall 102 , a rear coupling soundproof wall 103 , a pair of side coupling soundproof walls 104 , and an upper coupling soundproof wall 105 .

Both the front coupling soundproof wall 102 and the rear coupling soundproof wall 103 are soundproof walls facing the axial direction Da. The front coupling soundproof wall 102 is arranged on the axis line first side Da1 from the coupling device 10b and on the axis line second side Da2 from the second bearing device 67b. The rear coupling soundproof wall 103 is arranged on the second axial side Da2 from the coupling device 10b and on the first axial side Da1 from the generator casing 85. As shown in FIG. The front coupling soundproof wall 102 and the rear coupling soundproof wall 103 face each other in the axial direction Da.

A pair of side coupling soundproof walls 104 are soundproof walls facing the side direction Ds. Of the pair of side coupling soundproof walls 104, the first side coupling soundproof wall 104a is arranged on the first side direction Ds1 side of the coupling device 10b. The second side coupling soundproof wall 104b of the pair of side coupling soundproof walls 104 is arranged on the side of the coupling device 10b in the second lateral direction Ds2. The first side coupling soundproof wall 104a and the second side coupling soundproof wall 104b face each other in the lateral direction Ds. The end of the first side coupling soundproof wall 104a on the axis first side Da1 is connected to the end of the front coupling soundproof wall 102 in the first lateral direction Ds1. The end of the first side coupling soundproof wall 104a on the second side Da2 of the axis line is connected to the end of the rear coupling soundproof wall 103 in the first lateral direction Ds1. The end of the second side coupling soundproof wall 104b on the axis first side Da1 is connected to the end of the front coupling soundproof wall 102 in the second side direction Ds2. The end of the second side coupling soundproof wall 104b on the second side Da2 of the axis line is connected to the end of the rear coupling soundproof wall 103 in the second side direction Ds2.

The upper coupling soundproof wall 105 is a soundproof wall facing up and down. The upper coupling soundproof wall 105 is arranged above the coupling device 10b. The upper end of the front coupling soundproof wall 102 , the upper end of the rear coupling soundproof wall 103 , and the upper ends of the pair of side coupling soundproof walls 104 are all connected to the upper coupling soundproof wall 105 .

The lower end of the front coupling soundproof wall 102, the lower end of the rear coupling soundproof wall 103, and the lower ends of the pair of side coupling soundproof walls 104 are fixed to the device installation surface P on which the coupling device 10b is arranged. . Therefore, the coupling soundproof chamber 101 is fixed to the installation surface P of the device.

The first side coupling soundproof wall 104a is formed with a first through hole 106 penetrating from the inside to the outside of the coupling soundproof chamber 101 in the lower part of the first side coupling soundproof wall 104a. A second through hole 107 is formed in the upper coupling soundproof wall 105 so as to penetrate from the inside to the outside of the coupling soundproof chamber 101 .

Each of the plurality of soundproof walls forming the coupling soundproof room 101 has a substrate 109a having rigidity and a sound absorbing material 109b attached to this substrate 109a.

The intake channel frame 111 is fixed to the outer surface of the first side coupling soundproof wall 104a. The air intake channel frame 111 is formed with an air intake channel 112 into which air from the outside can flow. The air intake passage 112 meanders in the vertical direction and communicates with the first through hole 106 . Therefore, external air can be led into the coupling soundproof chamber 101 via the intake passage 112 . The exhaust channel frame 121 is fixed to the outer surface of the upper coupling soundproof wall 105 . An exhaust channel 122 capable of discharging air to the outside is formed in the exhaust channel frame 121 . The exhaust flow path 122 meanders in the side direction Ds and communicates with the second through hole 107 . Therefore, the air in the coupling soundproof chamber 101 can be exhausted to the outside via the exhaust flow path 122 . Both the intake channel frame 111 and the exhaust channel frame 121 have a rigid substrate 129a and a sound absorbing material 129b attached to the substrate 129a.

As described above, since the coupling device 10b of the present embodiment is surrounded by the coupling soundproof chamber 101, the sound leaking out of the coupling soundproof chamber 101 can be suppressed.

When the first coupling flange 20, the second coupling flange 30, the spacer 40, and the plurality of connectors 11 rotate within the coupling soundproof chamber 101, the temperature inside the coupling soundproof chamber 101 rises. Therefore, in the present embodiment, the intake channel frame 111 and the exhaust channel frame 121 are provided in the coupling soundproof chamber 101 so that the inside of the coupling soundproof chamber 101 and the outside can be communicated, and the inside of the coupling soundproof chamber 101 can be ventilated. I'm trying

By the way, if the inside of the coupling soundproof chamber 101 and the outside are communicated, the sound inside the coupling soundproof chamber 101 is likely to leak to the outside. Therefore, in the present embodiment, the intake channel 112 and the exhaust channel 122 meander so that the sound from the coupling soundproof chamber 101 does not go straight and leak to the outside. Furthermore, in the present embodiment, the air intake channel 112 and the exhaust channel 122 are meandered to increase the length of these channels, thereby increasing the amount of sound absorbed by the sound absorbing material 129b.

In this embodiment, the coupling device 10b has a coupling cover 90. However, if the coupling device 10b has the coupling cover 90, the coupling soundproof chamber 101 may be omitted. Further, when the coupling soundproof chamber 101 is provided, the coupling cover 90 of the coupling device 10b may be omitted.

"Variation"
The spacer 40 of the coupling device 10b is the rotating body according to the present invention. However, when the first coupling flange 20 and the second coupling flange 30 have holes and the rotation of these coupling flanges 20 and 30 generates self-excited noise caused by the holes, or the self-excited noise caused by the holes If there is a possibility of generating vibration, these coupling flanges 20, 30 may be treated as rotating bodies according to the present invention.

Also, any rotating body other than the spacer 40, the first coupling flange 20, and the second coupling flange 30 may be treated as the rotating body of the present invention as long as it rotates about the axis Ar. For example, in the above embodiments, the turbine rotor shaft 62 and the generator rotor shaft 82 have holes, and the rotation of these rotor shafts 62 and 82 generates self-excited noise caused by the holes. If there is a possibility of generating self-excited vibration, these rotor shafts 62, 82 may be treated as rotating bodies according to the present invention.

In the above embodiment, the steam turbine 60 having the moving blades 63 as the functional members and the generator 80 having the magnets 83 as the functional members are exemplified as the rotary machines. However, the rotating machine is not limited to these, and may be a gas turbine having rotor blades as a functional member, a pump having an impeller as a functional member, a water turbine having an impeller as a functional member, or a wind turbine having blades as a functional member. There may be.

Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above embodiments. Various additions, changes, replacements, partial deletions, etc. are possible without departing from the conceptual idea and spirit of the present invention derived from the content defined in the claims and equivalents thereof.

"Appendix"
For example, the rotating bodies in the above embodiments and modifications are grasped as follows.

(1) The rotating body in the first aspect is
Rotating bodies 1, 40 rotatable at a predetermined number of revolutions about an axis Ar have holes 3a, 3b, 46a opened at surfaces 2, 41 of the rotating bodies 1, 40, respectively. The acoustic natural frequency fa determined by the inner diameter of the holes 3a, 3b, 46a and the depth of the holes 3a, 3b, 46a is the circumference of the openings 5, 5a, 46oa of the holes 3a, 3b, 46a at the predetermined rotation speed. It deviates from the vortex generation frequency Fk determined by the speed U.

The inventor paid attention to the fact that when the rotors 1 and 40 rotate, eddies 6 are generated near the openings 5, 5a and 46oa of the holes 3a, 3b and 46a. Then, the inventor found that when the acoustic natural frequency fa of the holes 3a, 3b, 46a is close to the vortex generation frequency Fk of the vortex 6 generated around the openings 5, 5a, 46oa of the holes 3a, 3b, 46a, the holes 3a, 3b, 46a It was found that self-excited noise caused by holes 3a, 3b, and 46a can be suppressed when self-excited noise caused by holes 3b and 46a is generated and acoustic natural frequency fa is deviated from vortex generation frequency Fk. Therefore, in this aspect, the self-excited noise caused by the holes 3a, 3b, 46a can be suppressed.

(2) The rotating body in the second aspect is
In the rotors 1 and 40 in the first aspect, when the speed of sound is C, the depth of the holes 3a, 3b, and 46a is L, and the inner diameter of the holes 3a, 3b, and 46a is D, the acoustic natural frequency fa is , is expressed by the following equation.
f a = (C/4)/(L+0.85×D/2)
Assuming that U is the peripheral speed U of the openings 5, 5a, and 46oa rotating at the predetermined rotational speed, and St is the Strouhal number, the vortex generation frequency Fk is expressed by the following equation.
Fk = St x (U/D)

(3) The rotating body in the third aspect is
In the rotary bodies 1 and 40 according to the first aspect or the second aspect, the holes 3a and 46a are composed of cylindrical first inner peripheral surfaces 4a and 47a, ends of the first inner peripheral surfaces 4a and 47a, and the and second inner peripheral surfaces 4b, 47b connecting the surfaces 2, 41 of the rotating bodies 1, 40. The inner diameters of the second inner peripheral surfaces 4b, 47b gradually increase from the position of connection with the first inner peripheral surfaces 4a, 47a to the position of connection with the surfaces 2, 41. As shown in FIG.

In this aspect, the rotation of the rotors 1 and 40 can reduce the power of the vortex 6 generated near the openings 5a and 46oa of the holes 3a and 46a.

For example, the coupling devices in the above embodiments and modifications are understood as follows.
(4) The coupling device in the fourth aspect is
A spacer 40, which is a rotating body 40 according to any one of the first to third aspects, and a spacer 40 that is rotatable at the predetermined number of rotations about the axis Ar and that is based on the spacer 40. A first coupling flange 20 arranged on an axis first side Da1, which is one side in the axial direction Da in which the axis Ar extends, and a spacer 40 rotatable about the axis Ar at the predetermined number of rotations and the spacer 40 as a reference. Then, the second coupling flange 30 arranged on the second axial side Da2, which is the other side in the axial direction Da, the first coupling flange 20, the spacer 40, and the second coupling flange 30 are integrated. a connector 11 for rotatably connecting the first coupling flange 20, the spacer 40 and the second coupling flange 30 to each other;

In this aspect, when the first coupling flange 20, the spacer 40, and the second coupling flange 30 rotate together, the occurrence of self-excited noise caused by the hole 46a of the spacer 40 can be suppressed.

(5) The coupling device in the fifth aspect,
In the coupling devices 10a and 10b according to the fourth aspect, at least one of the first coupling flange 20 and the second coupling flange 30 is It has holes 25a, 26a, 35a, 36a which open at surfaces 23, 33 of 20, 30. The openings of the holes 25a, 26a, 35a, 36a are closed with lids 52, 53 that are removable from the holes 25a, 26a, 35a, 36a.

In this aspect, the holes 25a, 26a, 35a, 36a of the first coupling flange 20 or the second coupling flange 30 when the first coupling flange 20, the spacer 40, and the second coupling flange 30 rotate together. It is possible to suppress the generation of noise caused by

(6) The coupling device in the sixth aspect,
In the coupling device 10b according to the fourth aspect or the fifth aspect, the second An annular coupling cover 90 is provided to cover the outer circumference of the first coupling flange 20 , the outer circumference of the spacer 40 and the outer circumference of the second coupling flange 30 . The coupling cover 90 has a sound absorbing portion 92 containing a sound absorbing material 93 .

In this aspect, the coupling cover 90 can suppress sound leaking out of the coupling cover 90 .

(7) The coupling device in the seventh aspect,
In the coupling device 10b according to the sixth aspect, the coupling cover 90 has an annular shape centered on the axis Ar, and is formed with a plurality of through holes penetrating from the inner peripheral side to the outer peripheral side. It has a support member 91 that rests on it. The sound absorbing portion 92 is arranged on the outer peripheral side of the support member 91 and supported by the support member 91 .

(8) The coupling device in the eighth aspect,
In the coupling device 10b according to the seventh aspect, the sound absorbing portion 92 includes a plurality of sound absorbing members 93 arranged in a radial direction Dr with respect to the axis Ar, and a sound insulating plate 94 arranged between the plurality of sound absorbing members 93. , has

In this aspect, the coupling cover 90 can effectively suppress sound leaking out of the coupling cover 90 .

(9) The coupling device in the ninth aspect,
In the coupling device 10b according to the eighth aspect, the sound absorbing portion 92 is arranged between the support member 91 and the sound absorbing member 93 arranged innermost in the radial direction Dr among the plurality of sound absorbing members 93. It has a sound insulation plate 94 positioned thereon.

(10) The coupling device in the tenth aspect,
The coupling device 10b in the ninth aspect has an inner sound absorbing member 95 arranged between the support member 91 and the sound absorbing portion 92 in the radial direction Dr.

In this aspect, the inner sound absorbing material 95 can absorb part of the sound from the noise source before the sound from the noise source reaches the innermost sound insulating plate 94 . Therefore, in this aspect, by arranging the inner sound absorbing material 95, it is possible to effectively suppress the sound leaking out of the coupling device 10b.

For example, the coupling equipment in the above embodiments and modifications is grasped as follows.

(11) The coupling equipment in the eleventh aspect,
The coupling devices 10a and 10b according to any one of the fourth to tenth aspects and the coupling devices 10a and 10b are fixed to a device installation surface P on which the coupling devices are arranged. A coupling soundproof chamber 101 that covers the coupling device 10b apart from 10a and 10b. A wall forming the coupling soundproof chamber 101 has a sound absorbing material 109b.

In this aspect, the coupling soundproof chamber 101 can suppress the sound leaking out of the coupling soundproof chamber 101 .

(12) The coupling equipment in the twelfth aspect is
In the coupling device 100 according to the eleventh aspect, an intake passage frame 111 is arranged outside the coupling soundproof chamber 101 and is formed with an intake passage 112 through which air from the outside can flow; and an exhaust channel frame 121 arranged outside the ring soundproof chamber 101 and formed with an exhaust channel 122 capable of exhausting air to the outside. The coupling soundproof chamber 101 has a first through hole 106 and a second through hole 107 penetrating from the inside to the outside of the coupling soundproof chamber 101 . The intake passage 112 meanders and communicates with the first through hole 106 . The exhaust flow path 122 meanders and communicates with the second through hole 107 . Both the intake channel frame 111 and the exhaust channel frame 121 have a sound absorbing material 129b.

In this aspect, the air inside the coupling soundproof chamber 101 can be ventilated. If the air in the coupling soundproof chamber 101 can be ventilated in this way, the sound in the coupling soundproof chamber 101 can easily leak to the outside. Therefore, in this embodiment, the intake channel 112 and the exhaust channel 122 meander so that the sound from the coupling soundproof chamber 101 does not go straight and leak to the outside. Furthermore, in this embodiment, the air intake channel 112 and the exhaust channel 122 are meandered to increase the length of these channels, thereby increasing the amount of sound absorbed by the sound absorbing material 129b.

For example, the rotating mechanical equipment in the above embodiments and modifications can be grasped as follows.

(13) The rotary machine equipment in the thirteenth aspect,
The coupling devices 10a and 10b according to any one of the fourth to tenth aspects, the rotor 61 rotatable at the predetermined rotation speed about the axis Ar, and part of the rotor 61 It comprises a rotary machine 60 having a casing 65 that covers it, and an enclosure 70 that covers at least the casing 65 of the rotary machine 60 . The rotor 61 is fixed to a rotor shaft 62 extending in the axial direction Da about the axis Ar and fixed to the outer periphery of the rotor shaft 62. Rotating together with the rotor shaft 62, the rotor 61 is required for the rotary machine 60. It has a functional member 63 that performs a function and the first coupling flange 20 that is fixed to the end of the rotor shaft in the axial direction Da. The casing 65 covers the functional member 63 without covering the first coupling flange 20 . The axis Ar extends in directions including the horizontal direction. The enclosure 70 comprises an upper coupling soundproof wall 78 spaced upwardly from the coupling device 10b and a pair of side coupling soundproof walls spaced apart from the coupling device 10b in a lateral direction Ds perpendicular to the axis Ar. a wall 77; One of the pair of side coupling soundproof walls 77, a first side coupling soundproof wall 77a, is located on both sides of the side direction Ds in the first side direction Ds1 with the coupling device 10b as a reference. placed on the side. Of the pair of side coupling soundproof walls 77, the other second side coupling soundproof wall 77b is located on both sides of the side direction Ds in the second side direction Ds2 with the coupling device 10b as a reference. placed on the side. The upper coupling soundproof wall 78 and the pair of side coupling soundproof walls 77 are connected to each other. The upper coupling soundproof wall 78 and the pair of side coupling soundproof walls 77 have sound absorbing materials 79b.

In this aspect, since the coupling devices 10a and 10b are covered with the enclosure 70 of the rotary machine, it is possible to suppress the sound leaking out from the coupling devices 10a and 10b.

For example, the manufacturing method of the rotating body in the above embodiments and modifications is grasped as follows.
(14) The manufacturing method of the rotating body in the fourteenth aspect includes:
A manufacturing method for rotating bodies 1 and 40 which have holes 3a, 3b and 46a opened at surfaces 2 and 41 and rotate at a predetermined number of revolutions about an axis line Ar. In this manufacturing method, a design step S10 for designing the rotating bodies 1 and 40 having the holes 3 and 46, and the inner diameters of the holes 3 and 46 determined in the design step S10 and the depths of the holes 3 and 46 are determined. Depending on whether or not the acoustic natural frequency fa deviates from the vortex generation frequency Fk determined by the peripheral speed U of the openings 5 and 46o of the holes 3 and 46 at the predetermined rotation speed, the noise caused by the holes 3 and 46 Determination step S11 for determining whether or not there is a possibility that self-excited noise will occur; A redesign step S12 for correcting the sizes of the holes 3 and 46 determined in the design step S10 and a manufacturing step S13 for manufacturing the rotors 1 and 40 determined in the redesign step S12 are executed.

In the rotating bodies 1, 40 manufactured by the manufacturing method of this aspect, self-excited noise caused by the holes 3a, 3b, 46a can be suppressed, like the rotating bodies 1, 40 in the first aspect.

(15) The manufacturing method of the rotating body in the fifteenth aspect includes:
In the manufacturing method of the rotating body in the fourteenth aspect, when the speed of sound is C, the depth of the holes 3 and 46 is L, and the inner diameter of the holes 3 and 46 is D, the acoustic natural frequency fa is as follows: is represented by the formula
f a = (C/4)/(L+0.85×D/2)
The vortex generation frequency Fk is expressed by the following equation, where U is the peripheral speed U of the openings 5 and 46o when rotating at the predetermined number of revolutions, and St is the Strouhal number.
Fk = St x (U/D)

For example, the method for preventing noise from rotating bodies in the above embodiments and modifications is grasped as follows.
(16) The method for preventing noise from rotating bodies in the sixteenth aspect,
A noise prevention method for rotating bodies 1 and 40 which have holes 3 and 46 opening at surfaces 2 and 41 and rotate at a predetermined number of revolutions about an axis line Ar. In this noise prevention method, it is determined whether self-excited noise caused by the holes 3 and 46 is generated when the rotors 1 and 40 are rotated at the predetermined number of revolutions about the axis Ar. and a hole remodeling step S2 of increasing the depth of the holes 3, 46 or increasing the inner diameter of the holes 3, 46 when it is determined that the self-excited noise is generated in the determination step S1. and run

In the rotors 1, 40 in which the holes 3, 46 are modified by the noise prevention method of this aspect, self-excited noise caused by the holes 3, 46 can be suppressed, as in the rotors 1, 40 in the first aspect.

(17) The rotating body noise prevention method in the seventeenth aspect includes:
In the method for preventing noise from rotating bodies according to the sixteenth aspect, in the hole remodeling step S2, the inner diameters of the holes 3 and 46 gradually increase as they approach the surfaces 2 and 41. The corners of the holes 3, 46 and the inner peripheral surfaces are ground.

In the rotors 1, 40 in which the holes 3, 46 are modified by the noise prevention method of this aspect, the vortices generated near the openings 5a, 46oa of the holes 3a, 46a are similar to the rotors 1, 40 in the fourth aspect. power can be reduced.

According to one aspect of the present disclosure, it is possible to suppress the trouble of using the hole while suppressing the noise caused by the hole when the rotating body is rotated.

1: rotating body 2: surfaces 3, 3a, 3b: hole 4: inner peripheral surface 4a: first inner peripheral surface 4b: second inner peripheral surface 5, 5a: opening 6: vortex 10, 10a, 10b: coupling device 11: Connector 12: Bolt 13: Nut 20: First Coupling Flange 21: Peripheral Surface 22: Contact Surface 23: Non-Contact Surface (Surface)
24: bolt holes 25, 25a: jack holes 25s, 25sa: female screw 25o: openings 26, 26a: balance holes 26s: female screw 26o: opening 30: second coupling flange 31: outer peripheral surface 32: contact surface 33: non Contact surface (surface)
34: bolt holes 35, 35a: jack holes 35s, 35sa: female screw 35o: openings 36, 36a: balance hole 36s: female screw 36o: opening 40: spacer (rotating body)
41: outer peripheral surface (surface)
42: first contact surface 43: second contact surface 44: bolt hole 46: lifting holes 46o, 46oa: opening 47: inner peripheral surface 47a: first inner peripheral surface 47b: second inner peripheral surface 51: jack bolt 52 , 53: Threaded plug (lid)
54: Eye bolt 60: Steam turbine 61: Turbine rotor 62: Turbine rotor shaft 63: Moving blade (functional member)
64: Coupling flange 65: Turbine casing 67a: First bearing device 67b: Second bearing device 68: Bearing 69: Bearing casing 70: Enclosure 71: Front soundproof wall 72: Side soundproof wall 72a: First side soundproof wall 72b: Second side soundproof wall 73: Rear soundproof wall 73a: First rear soundproof wall 73b: Second rear soundproof wall 74: Upper soundproof wall 75: Post-shift soundproof wall 76: Retraction Side soundproof wall 76a: First retraction Side soundproof wall 76b: Second lead-in side soundproof wall 77: Side coupling soundproof wall 77a: First side coupling soundproof wall 77b: Second side coupling soundproof wall 78: Upper coupling soundproof wall 78m: Middle Edge 79a: Substrate 79b: Sound Absorbing Material 80: Generator 81: Generator Rotor 82: Generator Rotor Shaft 83: Magnet 84: Coupling Flange 85: Generator Casing 86: Coil 90: Coupling Cover 91: Support Material 92 : Sound absorbing portion 93: Sound absorbing material 93a: First sound absorbing material 93b: Second sound absorbing material 93c: Third sound absorbing material 93d: Fourth sound absorbing material 93e: Fifth sound absorbing material 94: Sound insulating plate 95: Inner sound absorbing material 100: Coupling Equipment 101: Coupling soundproof room 102: Front coupling soundproof wall 103: Rear coupling soundproof wall 104: Side coupling soundproof wall 104a: First side coupling soundproof wall 104b: Second side coupling soundproof wall 105 : Upper coupling soundproof wall 106: First through hole 107: Second through hole 109a: Substrate 109b: Sound absorbing material 111: Intake channel frame 112: Intake channel 121: Exhaust channel frame 122: Exhaust channel 129a: Substrate 129b: Sound absorbing material Ar: Axis Da: Axial direction Da1: Axis first side Da2: Axis second side Dc: Circumferential direction Dr: Radial direction Ds: Lateral direction Ds1: First lateral direction Ds2: Second lateral direction P: Device Installation surface

Claims (17)

1. In a rotating body that can rotate at a predetermined number of revolutions about an axis,
   Having a hole that opens on the surface of the rotating body,
   The acoustic natural frequency determined by the inner diameter of the hole and the depth of the hole deviates from the vortex generation frequency determined by the peripheral speed of the opening of the hole at the predetermined rotational speed.
   Rotating body.
2. In the rotating body according to claim 1,
   When the speed of sound is C, the depth of the hole is L, and the inner diameter of the hole is D, the acoustic natural frequency fa is expressed by the following formula,
   f a = (C/4)/(L+0.85×D/2)
   When the peripheral speed of the opening when rotating at the predetermined number of revolutions is U, and the Strouhal number is St, the vortex generation frequency Fk is expressed by the following equation.
   Fk = St x (U/D)
   Rotating body.
3. In the rotating body according to claim 1,
   The hole has a cylindrical first inner peripheral surface and a second inner peripheral surface connecting an end of the first inner peripheral surface and the surface of the rotating body,
   The inner diameter of the second inner peripheral surface gradually increases from the position of connection with the first inner peripheral surface toward the position of connection with the surface.
   Rotating body.
4. A spacer that is a rotating body according to any one of claims 1 to 3;
   a first coupling flange that is rotatable about the axis at the predetermined number of rotations and that is arranged on the first side of the axis, which is one side in the axial direction in which the axis extends with respect to the spacer;
   a second coupling flange rotatable about the axis at the predetermined number of rotations and arranged on the second side of the axis, which is the other side in the axial direction with respect to the spacer;
   a connector that interconnects the first coupling flange, the spacer, and the second coupling flange so that the first coupling flange, the spacer, and the second coupling flange can rotate together;
   A coupling device comprising a
5. A coupling device according to claim 4,
   At least one of the first coupling flange and the second coupling flange has a hole opening on the surface of the at least one coupling flange,
   The opening of the hole is closed with a lid that is removable from the hole,
   coupling device.
6. A coupling device according to claim 4,
   The outer circumference of the first coupling flange, the outer circumference of the spacer, and the outer circumference of the second coupling flange are separated from the first coupling flange, the spacer, and the second coupling flange in a radial direction with respect to the axis. Equipped with an annular coupling cover that covers
   The coupling cover has a sound absorbing portion containing a sound absorbing material,
   coupling device.
7. A coupling device according to claim 6, wherein
   The coupling cover has a support member which is annular about the axis and has a plurality of through holes penetrating from the inner peripheral side to the outer peripheral side,
   The sound absorbing portion is arranged on the outer peripheral side of the support member and supported by the support member,
   coupling device.
8. A coupling device according to claim 7, wherein
   The sound absorbing portion has a plurality of sound absorbing materials arranged in a radial direction with respect to the axis, and a sound insulating plate disposed between the plurality of sound absorbing materials.
   coupling device.
9. A coupling device according to claim 8, wherein
   The sound absorbing portion has a sound insulating plate disposed between the support member and the sound absorbing member disposed innermost in the radial direction among the plurality of sound absorbing members.
   coupling device.
10. A coupling device according to claim 9, wherein
    an inner sound absorbing material disposed radially between the support and the sound absorbing portion;
    coupling device.
11. A coupling device according to claim 4;
    a coupling soundproof chamber fixed to a device installation surface on which the coupling device is arranged, separated from the coupling device and covering the coupling device;
    with
    A wall forming the coupling soundproof chamber has a sound absorbing material,
    coupling equipment.
12. A coupling installation according to claim 11,
    an air intake channel frame disposed outside the coupling soundproof chamber and formed with an air intake channel through which air from the outside can flow;
    an exhaust channel frame disposed outside the coupling soundproof chamber and formed with an exhaust channel capable of exhausting air to the outside;
    with
    The coupling soundproof chamber has a first through hole and a second through hole penetrating from the inside to the outside of the coupling soundproof chamber,
    the intake flow path meanders and communicates with the first through hole,
    The exhaust flow path meanders and communicates with the second through hole,
    Both the intake channel frame and the exhaust channel frame have a sound absorbing material,
    coupling equipment.
13. A coupling device according to claim 4;
    a rotating machine having a rotor rotatable about the axis at the predetermined number of revolutions and a casing covering a portion of the rotor;
    an enclosure covering at least the casing of the rotating machine;
    with
    The rotor has a rotor shaft extending in the axial direction around the axis, and a functional member that is fixed to the outer periphery of the rotor shaft and rotates integrally with the rotor shaft to perform functions required of the rotating machine. , said first coupling flange secured to said axial end of said rotor shaft;
    the casing covers the functional member without covering the first coupling flange;
    the axis extends in a direction including a horizontal direction;
    The enclosure has an upper coupling noise wall spaced upwardly from the coupling device and a pair of side coupling noise walls spaced laterally from the coupling device perpendicular to the axis. ,
    One of the pair of side coupling soundproof walls, a first side coupling soundproof wall, is arranged on the side in the first lateral direction with respect to the coupling device, out of both sides in the lateral direction, the other second side coupling soundproof wall of the pair of side coupling soundproof walls is arranged on the second side direction side with respect to the coupling device, out of both sides in the lateral direction;
    the upper coupling noise barrier and the pair of side coupling noise barriers are connected to each other;
    the upper coupling sound barrier and the pair of side coupling sound barriers having a sound absorbing material;
    Rotating mechanical equipment.
14. In a method for manufacturing a rotating body that has a hole that opens on its surface and that rotates about an axis at a predetermined number of revolutions,
    a design step of designing a rotating body having the hole;
    Depending on whether the acoustic natural frequency determined by the inner diameter of the hole and the depth of the hole determined in the design process deviates from the vortex generation frequency determined by the peripheral speed of the opening of the hole at the predetermined rotation speed , a determination step of determining whether there is a possibility that self-excited noise caused by the hole is generated;
    a redesigning step of correcting the size of the hole determined in the designing step when it is determined in the determining step that there is a possibility that self-excited noise caused by the hole is generated;
    a manufacturing process for manufacturing the rotating body determined in the redesigning process;
    A method of manufacturing a rotating body that performs
15. In the method for manufacturing a rotating body according to claim 14,
    When the speed of sound is C, the depth of the hole is L, and the inner diameter of the hole is D, the acoustic natural frequency fa is expressed by the following formula,
    f a = (C/4)/(L+0.85×D/2)
    When the peripheral speed of the opening when rotating at the predetermined number of revolutions is U, and the Strouhal number is St, the vortex generation frequency Fk is expressed by the following equation.
    Fk = St x (U/D)
    A manufacturing method of a rotating body.
16. In a noise prevention method for a rotating body having a hole opening on the surface and rotating at a predetermined number of revolutions about an axis,
    a determination step of determining whether or not self-excited noise caused by the hole is generated when the rotating body is rotated about the axis at the predetermined number of revolutions;
    a hole remodeling step of increasing the depth of the hole or increasing the inner diameter of the hole when it is determined in the determination step that self-excited noise is occurring;
    A rotating body noise prevention method that performs
17. In the rotating body noise prevention method according to claim 16,
    In the hole modification step, the corner between the surface and the inner peripheral surface of the hole is ground so that the inner diameter of the hole gradually increases as it approaches the surface.
    A rotating body noise prevention method.

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