WO2017030182A1

WO2017030182A1 - Turbo device

Info

Publication number: WO2017030182A1
Application number: PCT/JP2016/074196
Authority: WO
Inventors: 洋平丹野; 剛風間; 松永　裕之; 橋本　泰司; 隆平塚原
Original assignee: 株式会社日立製作所
Priority date: 2015-08-19
Filing date: 2016-08-19
Publication date: 2017-02-23
Also published as: JP6553447B2; JP2017040184A

Abstract

Airtightness is improved, cost is reduced, and installation workability is improved for a nuts-and-bolts structure. In a bolt-fastening structure configured from an upper flange and lower flange having bolt holes, and also configured from studs, upper nuts, and lower nuts, the lower ends of the bolt holes in the lower flange are provided with female screw parts each having at least one screw thread.

Description

Turbo machine

Import by reference

This application claims the priority of Japanese Patent Application No. 2015-161532 filed on Aug. 19, 2015, and is incorporated herein by reference.

The present invention relates to a turbo machine such as a compressor or a pump, which is characterized by its bolt fastening.

With the development of the oil and gas industry, it is necessary to increase the capacity and pressure of gas handled in the industry, and as a result, there is a need to increase the pressure and diameter of turbomachines that handle gas.
As an example of a turbo machine, a rotor part composed of an impeller, a shaft, and the like may be rotatably accommodated in a casing and installed in a horizontal direction. And barrel type. The horizontal split type casing is a structure in which a rotor portion such as an impeller and a shaft is installed between upper and lower casings that are horizontally split in a direction parallel to the rotor shaft, and the flanges of the upper and lower casings are sealed by bolting. . On the other hand, the barrel-type casing has a structure in which an inner casing and a rotor portion are inserted in a cylindrical casing in the axial direction, and head covers at both ends of the cylindrical casing are fastened with bolts.

In the horizontal split type casing, the sealing part of the casing is firmly fastened with bolts to prevent leakage. Typical bolt fastening structures include a built-in bolt structure and a double nut bolt structure. The double bolt nut structure has a greater compression field due to the bolts in the object to be fastened by the bolts, that is, tightened. Therefore, it is an advantageous structure for improving the airtightness of the casing.

As a publicly known example related to this double nut bolt structure, in Patent Document 1, a pressurizing chamber sealed with a flexible member is formed on a mating surface of a horizontal joint flange of a steam turbine casing, and a fluid generated in the pressurizing chamber. It is fastened with both bolts and nuts while improving airtightness by the pressure of. Further, in Patent Document 2, in a structure in which both screw bolts used in a casing horizontal joint flange portion and a lower nut as an upper nut are fastened, the bolt hole diameter of the flange portion is partially reduced so that the bolt does not fall off during disassembly. ing.

JP-A-10-306707 Japanese Utility Model Publication No. 56-139808

In the double nut bolt structure in which the upper flange and the lower flange of the horizontal split type casing are fastened by the upper nut and the lower nut, when disassembling the upper casing for the maintenance inside the casing, the upper nut is removed from the lower casing. Stud and lower nut will come off. Therefore, when reassembling the casing, there is a problem that it is necessary to re-install the stud on the lower casing.

The present invention was made in order to solve the problem of re-installation work that occurs when a stud is detached during assembly and disassembly with respect to a turbo machine having a double nut bolt structure that is a fastening method of a horizontally divided casing. An object of the present invention is to provide a turbo machine having a double nut bolt structure that is inexpensive, has good installation workability, and good airtightness.

The present invention has a horizontally divided type casing including an upper casing and a lower casing, an upper flange formed on the upper casing and having a bolt hole, and a lower flange formed on the lower casing and having a bolt hole. The present invention relates to a turbo machine connected by both nut bolts.
The nut bolts have a male screw portion at the top and bottom, a stud that forms the bolt portion, an upper nut that has a female screw portion that meshes with the male screw portion formed above the stud, and a lower portion of the stud. And a lower nut having a female threaded portion that meshes with the male threaded portion.

Further, the lower flange has a female screw portion that meshes with a male screw portion formed below the stud at the lower end of the bolt hole formed in the lower flange.

Further, a non-threaded portion is provided in a part of the male screw portion at the lower end of the stud so as to be sandwiched between the first male screw portion and the second male screw portion, and the upper end portion of the female screw portion in the lower flange and the The lower end portion of the second male screw portion above the non-thread portion of the stud may come into contact. Furthermore, you may provide a non-contact part in a part on contact surface of the said upper flange and the said lower flange.

In addition, the turbo machine of the present invention has a horizontally divided type casing including an upper casing and a lower casing, and is formed in the upper casing and has an upper flange having a bolt hole, and is formed in the lower casing. The nut bolt has a male screw part at the top and bottom, a stud that forms the bolt part, and a female screw that meshes with the male screw part formed above the stud An upper nut having a portion, and the lower flange has a female screw portion that meshes with a male screw portion formed below the stud at a lower end of the bolt hole formed in the lower flange. Also good. Furthermore, you may provide a non-contact part in a part on contact surface of the said upper flange and the said lower flange.

In addition, the turbomachine of the present invention has a horizontally divided casing including an upper casing and a lower casing, and is formed in the upper casing, an upper flange having a bolt hole, and a bolt formed in the lower casing. A lower flange having a hole is connected with a nut bolt, and the nut bolt has a male screw portion at the top and bottom, a stud that forms the bolt portion, and a female screw that meshes with the male screw portion formed above the stud An upper nut having a portion, and the lower flange has a female screw portion that meshes with a male screw portion formed below the stud at a lower end of the bolt hole formed in the lower flange. Also good. Furthermore, you may provide a non-contact part in a part on contact surface of the said upper flange and the said lower flange.

In the both nut bolt structure according to the present invention, even when the upper nut is removed by the female screw portion provided at the lower end of the bolt hole in the lower flange, the stud can be engaged with the female screw portion to prevent the stud and the lower nut from falling. it can. That is, when disassembling and reassembling the casing during maintenance inside the casing, the upper casing can be removed with the stud held on the lower casing, and only the work of attaching and removing the upper nut is required. This eliminates the need to reposition the studs, saving time and labor. In addition, since it is not necessary to provide a special mechanism for the stud, there is no processing cost for the stud. This structure can be applied to a turbo machine having a bolt fastening portion such as a compressor, a pump, and a steam turbine.
Other objects, features and advantages of the present invention will become apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

1 is an external view of a turbo machine to which the present invention is applied. 1 is a configuration diagram of a double nut bolt structure according to Embodiment 1, and is a cross section taken along line AA of FIG. It is an enlarged view of the b section in FIG. It is a block diagram of the both nut bolt structure which concerns on Embodiment 2. FIG. It is an enlarged view of the b section in FIG. It is a block diagram of the both bolt structure which concerns on Embodiment 3. It is an enlarged view of the b section in FIG. It is a block diagram of the both nut bolt structure which concerns on Embodiment 4. It is an arrow view from CC direction in FIG.

Embodiment 1
FIG. 1 is an external view of a turbo machine to which the present invention is applied. 2 and FIG. 3 show a configuration diagram of a double-bolt nut structure according to the first embodiment. 2 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 3 is an enlarged view of a portion b in FIG.

As shown in FIG. 1, the casing is divided in the horizontal direction and includes an upper casing 101, a lower casing 102, and a bolt fastening portion 103. There is an upper flange 104 extending in the horizontal direction around the upper casing 101, and a lower flange 105 in the horizontal direction around the lower casing 102. By fastening the upper and lower flanges with bolts, High pressure gas is sealed. The lower casing 102 is provided with a gas suction pipe 120 and a gas discharge pipe 121. Although not shown in the figure, a compressor 10 that is one of turbomachines is configured in a casing in which a rotor portion of a compressor such as an impeller and a shaft is installed through a bearing installed in a bearing installation unit 130 in a horizontal direction. The

In FIG. 2, both nut bolt structures 100 include a stud 106, an upper nut 107, a lower nut 108, an upper flange 104, a lower flange 105, a bolt hole 109 in the upper flange 104, and a bolt hole 110 in the lower flange 105. The internal thread portion 111 is configured. The upper flange 104 and the lower flange 105 are installed in a horizontal direction, and the bolt hole 109 and the bolt hole 110 are opened in a vertical direction in principle. The female thread portion 111 is provided at the lower end of the lower flange 105, and the number of threads is at least one and is smaller than the number of threads necessary for fastening the lower nut 108 and the stud 106.

The function of the present invention will be described according to the procedure at the time of assembly. The stud 106 is inserted into the bolt hole 110 of the lower flange 105 of the lower casing 102 installed at a specified location, and the lower male screw portion 113 is screwed into the female screw portion 111 at the lower end of the bolt hole 110 of the lower flange 105. The male screw portion 113 is protruded to the outside of the lower flange 105 by a length necessary for fastening with the lower nut 108, and the lower nut 108 is attached. At this time, all the studs 106 are installed in the lower casing 102. Next, the upper casing 101 is installed so that the contact surface 112 contacts while adjusting the stud 106 so that the stud 106 enters the bolt hole 109. Then, the upper nut 107 is attached to the stud 106, and the upper nut 107 and the lower nut 108 are tightened while adjusting the tightening state while confirming the tightening state with the lower nut 108 to complete the tightening. At the time of fastening, as shown in FIG. 3, the stud 106 is fastened by the female screw portion 111 and the screw portion of the lower nut 108. In the both nut bolt structure 100, as shown in FIG. 3, since the lower male screw portion 113 of the stud 106 and the female screw portion 111 in the lower flange 105 are engaged with each other, even when the upper nut 107 is removed, The nut 108 cannot be removed. That is, in the double nut bolt structure 100 of the present invention, when the casing is disassembled and reassembled during maintenance inside the casing, the state in which the stud 106 is installed in the lower casing 102 can be maintained. Only the removal work is required, and the installation workability of the bolt fastening portion is improved. In particular, in large casings where large-diameter bolts are used, the weight of the bolts is large, so a crane may be required to install the bolts in the bolt fastening part, but the studs can be held in the lower casing. The use frequency of the crane can be reduced and workability can be improved. Moreover, it is not necessary to provide a special structure for preventing the fall of the stud, and the stud processing cost does not occur.

2 and 3 show the structure in which the upper casing is removed when the casing is disassembled, but when the casing is disassembled, the upper casing 101 side is not removed, but the lower casing 102 side is removed. There is. In the case of a structure in which the lower casing is removed, an internal thread portion corresponding to the internal thread portion 111 may be provided at the upper end of the upper flange 104. In this case, when the lower nut is removed for disassembly, the stud is supported by the internal thread portion provided in the bolt hole of the upper casing and held by the upper casing. At the time of assembly, the stud held by the upper casing is inserted into the bolt hole of the lower casing, installed, and fastened with the lower nut, so that the rearrangement of the stud is unnecessary.

Embodiment 2
4 and 5 show a block diagram of a double nut bolt structure according to Embodiment 2 of the present invention. 4 shows the entire structure of both bolts and nuts 400, and FIG. 5 is an enlarged view of part b in FIG. In the double nut bolt structure 400, the description of the portion having the same configuration and function as the double nut bolt structure 100 of FIG.

The double nut bolt structure 400 is a structure in which a non-threaded portion 403 is added in the lower male screw portion 402 of the stud 401 with respect to the double nut bolt structure 100. The first male screw portion 404 is installed on the lower end side, the non-screw portion 403 is installed above the first male screw portion 404, and the second male screw portion 405 is installed above the first male screw portion 403. The length of the non-threaded portion 403 is made longer than the female threaded portion 406 below the lower flange 416. Further, the diameter of the non-threaded portion 403 is smaller than the outer diameter of the first male screw portion 404 and the second male screw portion 405.

By providing the non-threaded portion 403, when the stud 401 is installed in the lower flange 416, the first male threaded portion 404 of the lower male threaded portion 402 is screwed into the female threaded portion 406, and then the non-threaded portion 403 is Without contacting the portion 406, the lower end portion of the second male screw portion 405 of the lower male screw portion 402 contacts the upper end portion of the female screw portion 406. That is, after the first male threaded portion 404 passes through the female threaded portion 406, the second male threaded portion 405 automatically contacts the female threaded portion 406 by the weight of the stud 401, thereby preventing the stud 401 from falling. Since the position where the female screw portion 406 and the second male screw portion 405 contact is always constant, the relative position between the stud 401 and the lower flange 416 can always be determined to be constant. At that time, the first male screw portion 404 of the stud 401 can be held in a state of protruding from the lower flange 416. Even if the upper casing 101 is removed, the stud 401 is held by the lower flange 416 of the lower casing 102. The rearrangement of the stud 401 is not necessary. Further, the protruding amount of the first male screw portion 404 from the casing is constant, and a lower nut 407 is assembled to the first male screw portion 404 to fasten the upper flange 415 and the lower flange 416. Further, since the non-threaded portion 403 is not engaged, the first male threaded portion 404 and the female threaded portion 406 are not engaged with each other.

Embodiment 3
6 and 7 show a block diagram of a double bolt structure according to Embodiment 3 of the present invention. 6 shows the entire bolt-nut structure 500, and FIG. 7 is an enlarged view of a portion b in FIG. In the double bolt structure 500, the description of the parts having the same configuration and function as the double nut bolt structure 100 of FIG. The double bolt structure 500 has a female screw portion 503 in which the length of the female screw portion 111 in the double nut bolt structure 100 is set to a length that secures a thread necessary for bolt fastening, and the lower nut 108 is omitted. In the both bolt structure 500, the stud 501 and the female threaded portion 502 are engaged with each other, and the length of the female threaded portion 502 is determined so that the number of threads necessary for strength is obtained at the engaging portion.

In the present embodiment, by providing the female screw portion 502 at the lower end in the lower flange 503 with a length close to the lower end portion of the lower flange 503, it is possible to obtain a tightening effect equivalent to that of both nut bolt structures. Since the stud 501 can be held by the lower flange 503 of the lower casing 102 even if the upper casing 101 is removed, it is not necessary to rearrange the stud 501. Further, since the lower nut is not necessary, the material, production, work cost, etc. can be reduced. Note that the lowermost end of the female thread portion 502 in the lower flange 503 may penetrate the lower flange lower end, or a positioning hole smaller than the bolt diameter may be left or not penetrated for positioning.

Embodiment 4
8 and 9 show a block diagram of a double nut bolt structure 300 according to Embodiment 4 of the present invention. FIG. 8 shows the entire structure of both bolts and nuts 300, and FIG. 9 is a view of the lower flange 303 in FIG. In the double nut bolt structure 300, the description of the parts having the same configuration and function as the double nut bolt structure 100 of FIG. Both nut bolt structures 300 are configured by adding a non-contact portion 301 to the both nut bolt structures 100.

8 and 9, as the non-contact part 301, a part of the contact part 304 of the upper flange 302 and the lower flange 303 is contacted so as to be a circular and concave part coaxially with the centers of the bolt holes 309 and 310. An example in which a step which is lower than the surface 304 is provided is shown. By providing the non-contact portion 301, the contact area of the contact portion 304 is reduced, so that the surface pressure, which is a force per unit area generated in the contact portion 304 due to the bolt axial force, is increased and the airtightness is improved. is there. By improving the airtightness per bolt, it is possible to reduce the number of bolts required for fastening as a whole casing, reducing bolt costs, producing bolt fastening parts by reducing bolt holes, working costs, etc. There is an economic effect of reduction. The shape of the non-contact portion 304 is not limited to a circle, and the arrangement position of the non-contact portion 304 may be symmetric or asymmetric with respect to the circumferential direction around the axis of the stud 305. Further, the depth d in the flange of the non-contact portion 304 is arbitrary as long as there is no problem with the strength of the flange, and the non-contact portion 304 may be provided on the upper flange 302 side. In FIG. 8, the non-contact portion is provided for the first embodiment shown in FIG. 2, but the present invention can be similarly applied to the other second and third embodiments.

By adopting the embodiments described above, it is possible to reduce the cost and improve the installation workability with respect to the double nut bolt structure effective for improving the airtightness of the casing. By improving the airtightness, it is possible to reduce the number of bolts necessary for fastening, leading to reduction of the material, production, work cost, etc. of the bolt fastening portion.
While the above description has been made with reference to exemplary embodiments, it will be apparent to those skilled in the art that the invention is not limited thereto and that various changes and modifications can be made within the spirit of the invention and the scope of the appended claims.

DESCRIPTION OF SYMBOLS 10 Compressor 100 Double nut bolt structure 101 Upper casing 102 Lower casing 103 Bolt fastening part 104 Upper flange 105 Lower flange 106 Stud 107 Upper nut 108 Lower nut 109 Upper flange inner bolt hole 110 Lower flange inner bolt hole 111 Female thread part 112 Contact part 113 Lower male screw portion 300 Double nut bolt structure 301 Non-contact portion 302 Upper flange 303 Lower flange 304 Contact portion 305 Stud 307 Upper nut 308 Lower nut 309 Upper flange inner bolt hole 310 Lower flange inner bolt hole 311 Female screw portion 400 Dual nut bolt structure 401 Stud 402 Lower male screw portion 403 Non-threaded portion 404 First male screw portion 405 Second male screw portion 406 Female screw portion 407 Lower nut 408 Upper nut 409 Upper flange inner bolt hole 10 the lower flange in the bolt holes 415 on flange 416 under flange 417 contacts portion 500 both bolt structure 501 below the male screw portion 502 internally threaded portion 503 the lower flange 508 on the flange 509 on the nut 510 on the flange in the bolt holes 511 in the bottom flange bolt holes 512 contact portion

Claims

A horizontally divided casing including an upper casing and a lower casing;
An upper flange formed in the upper casing and having a bolt hole; and
A turbomachine formed in the lower casing and connecting a lower flange having a bolt hole with both nut bolts,
Both nut bolts are
A stud having a male threaded portion on the top and bottom and forming a bolt portion;
An upper nut having a female threaded portion that meshes with a male threaded portion formed above the stud;
A lower nut having a female threaded portion that meshes with a male threaded portion formed below the stud;
Have
In the lower flange,
At the lower end of the bolt hole formed in the lower flange,
A turbomachine having a female threaded portion that meshes with a male threaded portion formed below the stud.
In claim 1,
A non-threaded part is provided in a part of the male threaded part at the lower end of the stud so as to be sandwiched between the first male threaded part and the second male threaded part vertically, and the upper end part of the female threaded part in the lower flange and the stud A turbomachine, wherein a lower end portion of the second male screw portion above the non-screw portion is in contact.
In claim 1 and claim 2,
A turbomachine characterized in that a non-contact portion is provided on a part of a contact surface between the upper flange and the lower flange.
In Claim 1 to Claim 3,
The turbo machine characterized in that the shape of the non-contact portion is symmetrical in the circumferential direction about the axis of the stud.
A horizontally divided casing including an upper casing and a lower casing;
An upper flange formed in the upper casing and having a bolt hole; and
A turbomachine that is formed in the lower casing and connects a lower flange having a bolt hole with a nut bolt,
The nut bolt is
A stud having a male threaded portion on the top and bottom and forming a bolt portion;
An upper nut having a female threaded portion that meshes with a male threaded portion formed above the stud;
Have
In the lower flange,
At the lower end of the bolt hole formed in the lower flange,
A turbomachine having a female threaded portion that meshes with a male threaded portion formed below the stud.
In claim 5,
A turbomachine characterized in that a non-contact portion is provided on a part of a contact surface between the upper flange and the lower flange.
In claim 6,
The turbo machine characterized in that the shape of the non-contact portion is symmetrical in the circumferential direction about the stud axis.