JP2009036062A - Turbo machine rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce imbalance due to eccentricity of a nut of a rotor which is a rotating body, also to reduce unbalance correction time, and to prevent looseness of the nut. <P>SOLUTION: A fastening member of the rotating body fixing and retaining a plurality of parts composing the rotating body is provided with: a fastening bolt which has a screw connection part comprising an external screw part provided with threads and a bar shape part not having threads; a fastening part of which screw connection comprising an internal screw part provided with threads and a hole shape part not having threads and which engages with the screw connection part of the fastening bolt; at least three key grooves formed in parallel with a shaft of the rotating body on either of the bar shape part of the fastening bolt and the hole shape part of the fastening part; and a key inserted between the bar shape part of the fastening bolt and the hole shape part of the fastening part engaging with the fastening bolt so as to fit in the key groove. The key grooves are provided at an even interval on concentric circles of the bar shape part or the hole shape part on which the key grooves are formed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a turbomachine rotor in which a plurality of rotor parts such as a gas turbine and a compressor are fixed and held by fastening bolts.

  When tightening a nut to a fastening bolt in a rotor of a turbomachine such as a centrifugal compressor or a gas turbine, which is generally used and fixed to a plurality of rotor parts by fastening bolts and nuts, the fastening bolt and the nut Since there are manufacturing tolerances, the nut is eccentrically screwed with the fastening bolt. In the above-described centrifugal compressor and gas turbine, since the ratio of the weight of the nut to the weight of the entire rotor is large, the eccentricity of the nut has a significant effect on the rotational balance when the rotor rotates.

  In turbo machines such as centrifugal compressors and gas turbines, in order to correct the imbalance that occurs during rotor assembly, the rotor is mounted on a balance machine, and work such as cutting the rotor or attaching balance weights is performed. However, it takes a lot of time and labor to remove this imbalance accurately.

  As a technique for reducing rotor unbalance with respect to a turbo machine in which a plurality of rotor parts are fixed and held with fastening bolts, for example, Patent Document 1 proposes a residual unbalance removal method for a gas turbine rotor.

  However, Patent Document 1 (WO 01 / 86130A1) does not disclose a means for correcting the rotor unbalance due to the eccentricity of the nut when the nut is tightened when the rotor is assembled.

  Next, when the tightened nut is loosened during the operation of the turbomachine, the rotor parts that have been fixed and held may come off during the operation, leading to large vibrations and damage of the machine.

  As described above, as a technique related to the locking of the nut, as described above, after tightening the nut, methods such as caulking between the fastening bolt and inserting a pin are generally used.

WO01 / 86130A1

  In the turbomachine rotor structure in which the above-described plurality of rotor parts are fixedly held by fastening bolts, a great amount of time and labor are required to accurately remove the unbalance after the rotor is assembled. An object of the present invention is to provide a turbomachine rotor capable of easily correcting a rotor unbalance caused by eccentricity between a fastening bolt and a fastening part when a fastening part such as a nut is screwed onto the fastening bolt.

  In order to achieve the above object, in the turbomachine rotor, the fastening bolts and fastening parts for fixing and holding a plurality of rotor parts, and the fastening bolts so that the fastening bolts and the fastening parts can be centered. Or it has the some key inserted in the some keyway arrange | positioned at the screwing part of the said fastening component.

  A key groove is arranged in the screwing part of the fastening bolt or the screwing part of the fastening part, and the fastening bolt and the fastening part are arranged by arranging the key so that the fastening bolt and the fastening part can be centered. When screwed, centering can be performed simply by inserting a key into the keyway. Further, it is possible to prevent loosening by the contact force of the key instead of the pin. With this configuration, it is possible to easily correct the rotor unbalance due to the eccentricity of the fastening member with respect to the fastening bolt, and it is possible to shorten the time for removing the unbalance after the rotor is assembled and to reduce the labor.

  According to the present invention, in a turbomachine rotor in which a plurality of rotor parts are fixed and held by fastening members such as fastening bolts and nuts, the rotor unbalance due to the eccentricity of the fastening members with respect to the fastening bolts can be easily corrected, and the rotor assembly It is possible to shorten the time for the subsequent unbalance removal and reduce the labor.

  Hereinafter, the present invention will be described in detail based on the illustrated embodiments.

  FIG. 1 shows an example of the structure of fastening bolts and fastening parts of a turbomachine rotor according to the present invention. In this example, a nut is used as a fastening part.

  FIG. 1 shows an example in which a keyway is provided on the nut side. As shown in FIG. 2, the threaded portion of the fastening bolt 1 shown in FIG. 1 includes a male screw portion L1 provided with a thread and a round bar portion L2 where no screw thread exists. On the other hand, as shown in FIG. 3, the nut 2 also has a threaded portion composed of a female thread portion L3 provided with a thread and a round hole portion L4 having no thread, and the round hole L4 has a key of the same size. Four grooves 3 are formed. The key grooves 3 are preferably arranged at equal intervals, but may be arranged so that the key can be inserted so that the fastening bolt and the fastening component can be aligned concentrically.

  After the nut 2 is screwed onto the fastening bolt 1 and tightened, the keys 4 having the same dimensions are inserted into the key grooves 3 described above. As the shape of the key 4, the flat key shown in FIG. 4 or the curved surface key shown in FIG. 5 is used. In the case of the curved surface key shown in FIG. 5, the contact surface with the bolt has the same shape as the curved surface of the bolt outer diameter. Further, in both the flat key shown in FIG. 4 and the curved surface key shown in FIG. 5, gradient portions L5 and L7 are formed with respect to the key insertion direction so that the key can be easily inserted into the key groove. L6 and L8 are the same cross section.

  The key 4, the fastening bolt 1, and the nut 2 are manufactured with dimensional tolerances such that the key 4, the fastening bolt 1, and the nut 2 are fit together after the key 4 is inserted. Since the key 4 and the fastening bolt 1 and the key 4 and the nut 2 have an interference fit, a contact force acts between the key 4 and the fastening bolt 1 and the key 4 and the nut 2 to prevent the nut from loosening. It is done. Compared with the flat key shown in FIG. 4, the curved key shown in FIG. 5 has a larger contact area, so that the effect of preventing the nut from loosening is increased.

  FIG. 6 shows an example of a procedure for aligning the nut, which is stopped due to the eccentricity of the nut center, with respect to the center of the fastening bolt. The arrow in the figure indicates the direction of movement of the nut.

  As shown in FIG. 6A, initially, the nut 2 is eccentrically stopped with respect to the center of the fastening bolt 1. The key groove 3a in the eccentric direction has a gap that is reduced by the eccentric amount of the nut, but the key 4a is inserted into the key groove 3a as shown in FIG. 6-2. When the key 4a is inserted, the key 4a and the fastening bolt 1, and the key 4a and the nut 2 are manufactured with a dimensional tolerance of the interference fit, so that the nut 2 is moved in the radial direction in which the key 4a is inserted. Next, as shown in FIG. 6-3, the key 4b is inserted into the key groove 3b in a direction shifted by 90 degrees from the above-described key groove. As a result, as shown in FIG. 6-4, the nut also moves in the radial direction deviated 90 degrees from the above. By inserting the keys 4c and 4d into the remaining two key grooves 3c and 3d shown in FIG. 6-5, the center alignment of the final nut and the fastening bolt is performed as shown in FIG. 6-6.

The key groove described above may be provided at three locations. FIG. 7 shows an example of a procedure for aligning the nut, which is stopped when the center of the nut is eccentric, with the center of the fastening bolt in the case of three key grooves. As shown in FIG. 7A, initially, the nut 2 is eccentrically stopped with respect to the center of the fastening bolt 1. As shown in FIG. 7-2, the key 4a is inserted into the key groove 3a. When the key 4a is inserted, since the key 4a and the fastening bolt 1, and the key 4a and the nut 2 are manufactured with dimensional tolerances of interference fit, the nut 2 is moved in the radial direction in which the key 4a is inserted. Next, the key 4b is inserted into the key groove 3b in a direction shifted by 120 degrees from the key groove 3a shown in FIG. As a result, as shown in FIG. 7-4, the nut 2 also moves in the radial direction shifted by 120 degrees from the above.
By inserting the key 4c into the remaining one key groove 3c shown in FIG. 7-5, as shown in FIG. 7-6, the center position of the final nut and the fastening bolt is aligned.

  When disassembling the fastening bolt 1 and the nut 2 shown in FIG. 1, the diameter D1 of the round bar provided on the bolt shown in FIG. 2 and the diameter D2 of the round hole provided on the nut shown in FIG. A tool such as pliers is inserted into the gap 5 formed by the above, the inserted key 4 is pulled out, and the fastening bolt 1 and the nut 2 are disassembled. When the dimensions of the fastening bolts 1 and nuts 2 are relatively small and the gap 5 is small, the diameter D2 of the round hole provided in the nut 2 is made relatively larger than the diameter D1 of the round bar provided in the bolt. Therefore, the clearance 5 may be secured. In the embodiment shown in FIG. 1, when the gap 5 is small, as shown in FIG. 8, on the nut side, on both sides of the surface facing the key rod round bar L2 among the surfaces constituting the key groove. A groove portion having a length L9 may be formed so as to have a gap between the two surfaces 6a and 6b and the key at the time of insertion, and a space for inserting a tool may be secured.

  According to the present embodiment, the center position of the nut and the fastening bolt can be aligned by inserting the key into the key groove of the fastening part in the fastening parts such as the fastening bolt and nut of the turbomachine rotor. Since the alignment can be performed only by inserting the key, the adjustment process can be simplified. It is possible to reduce the unbalance of the rotor due to the eccentricity of the fastening member with respect to the fastening bolt, to shorten the time for removing the unbalance after the rotor is assembled, and to reduce the labor.

  Next, an embodiment in which a key groove is provided on the fastening bolt side will be described. As shown in FIG. 10, the fastening bolt 7 has a threaded portion composed of a male threaded portion L10 provided with a thread and a round bar portion L11 where no thread is present, and the keyway 9 of the same size is formed in the round bar portion L11. The place is formed. The key grooves 9 are preferably arranged at equal intervals, but may be arranged so that the fastening key and the fastening component can be aligned concentrically by inserting a ¥ key. On the other hand, as shown in FIG. 11, the nut 8 also includes a threaded portion including a female screw portion L12 provided with a screw thread and a round hole portion L13 where no screw thread exists.

  As shown in FIG. 9, after a nut 8 is screwed onto the fastening bolt 7 and tightened, the keys 10 having the same dimensions are inserted into the key grooves 9 described above. A contact force acts between the key 10 and the fastening bolt 7 and between the key 10 and the nut 8, and a nut locking effect is obtained.

  The shape of the key is the flat key shown in FIG. 4 or the curved key shown in FIG. In the case of the curved surface key shown in FIG. 12, the contact surface with the nut has the same shape as the curved surface of the inner diameter of the nut, and a gradient portion L14 is provided in the key insertion direction. Further, the key 10, the fastening bolt 7, and the nut 8 are manufactured with dimensional tolerances such that the key 10 and the fastening bolt 7 and the key 10 and the nut 8 are fitted together after the key 10 is inserted.

  Since the key 10 and the fastening bolt 7 and the key 10 and the nut 8 have an interference fit, a contact force acts between the key 10 and the fastening bolt 7 and between the key 10 and the nut 8 to prevent the nut from loosening. . Compared with the flat key shown in FIG. 4, the curved surface key shown in FIG. 12 has a larger contact area, so that the effect of preventing the nut from loosening is increased.

  In the embodiment of FIG. 9, the procedure shown in FIG. 6 and FIG. 7 described above can be applied to the procedure of aligning the nut, which is stopped due to the eccentricity of the nut center with respect to the center of the fastening bolt.

  Also in the present embodiment, the center position of the nut and the fastening bolt can be adjusted by inserting a key into the key groove of the fastening part in the fastening part such as a fastening bolt or nut of the turbomachine rotor. Since the alignment can be performed only by inserting the key, the adjustment process can be simplified. It is possible to reduce the unbalance of the rotor due to the eccentricity of the fastening member with respect to the fastening bolt, to shorten the time for removing the unbalance after the rotor is assembled, and to reduce the labor.

  Next, the Example which applied the fastening bolt and fastening component of this invention to the rotor of the centrifugal compressor as an example of a turbomachine is described.

  First, the rotor structure of the centrifugal compressor will be described with reference to FIG. The rotor of the centrifugal compressor is mainly composed of a counterweight rotor 12 for supporting the entire rotor, a compressor rotor 13, a fastening bolt 14 for fastening the rotors together, and a nut 15. These parts are integrated on the same axis. It is combined with. Further, a cap 17 is provided at the tip of the fastening bolt 14 in order to allow the working fluid 16 to flow smoothly. One of the fastening bolts 14 is screwed into the counterweight rotor 12 and the other is joined to the entire rotor by tightening the nut 15 at the end face of the compressor rotor. The counterweight rotor 12 and the compressor rotor 13 are provided with an inlay portion 18 that fits to each other, and the center of the counterweight rotor and the compressor rotor is brought out by the fitting tolerance of the inlay portion 18. The fastening bolt 14 is provided with a stepped portion 19, and the center of the fastening bolt 14 and the compressor rotor 13 is brought out by fitting tolerance between the stepped portion 19 and the compressor rotor 13, and the counterweight rotor 12, The three cores of the compressor rotor 13 and the fastening bolt 14 are integrally formed. A washer 20 is inserted between the nut 15 and the compressor rotor 13, and the nut 15 is prevented from loosening by bending the tip of the washer 20 toward the nut 15 and the compressor rotor 13. The cap 17 can be prevented from loosening by caulking the fastening bolt tip 21.

  FIG. 14 shows an example in which a key groove is provided on the nut 15 and cap 17 side, and FIG. 15 shows a key groove on the fastening bolt 14 side. The structure of the cap 17 portion is the same as the structure shown in FIGS. That is, the key groove may be provided on the cap 17 side or may be provided on the fastening bolt 14 side.

  FIG. 16 shows a cap structure in the case where the key groove is provided on the cap side, which is composed of a female screw portion L16 provided with a thread and a round hole portion L17 having no thread, and the round hole portion L17 includes A key groove 26 is formed. FIG. 17 shows a cap structure in the case where the key groove is provided on the fastening bolt side, and is composed of a female screw portion L18 provided with a thread and a round hole portion L19 where no screw thread exists. 6 and 7, the number of keys and key grooves may be four or three.

  After the entire rotor is coupled by the fastening bolt 14, the nut 15, and the cap 17, the key is inserted into the key groove provided in the fastening bolt 14, the nut 15, and the cap 17, thereby the counterweight rotor 12, the compressor rotor 13, The fastening bolt 14, the nut 15, and the cap 17 are all centered together, and the rotor imbalance related to the eccentricity of the nut 15 and the cap 17 can be reduced. Since the alignment can be performed only by the operation of inserting the key, the adjustment process can be simplified, the time relating to the unbalance removal after the rotor assembly can be shortened, and the labor can be reduced.

  Next, an example in which the present invention is applied to a gas turbine as shown in FIG. 18 will be described as another example of a turbo machine.

  A gas turbine shown in FIG. 18 includes a compressor 28 that compresses air 27 sucked from the atmosphere, a combustor 30 that mixes compressed air compressed by the compressor 28 with fuel 29, and generates combustion gas. 28 and a rotor 33, and a turbine 31 that obtains shaft power by combustion gas, and a generator 32 that generates power by transmitting shaft power of the turbine through a shaft 34.

  19, the rotor structure of the gas turbine shown in FIG. 18 will be described in more detail. FIG. 19 shows a rotor structure mainly used for a medium / small capacity gas turbine. The gas turbine rotor is mainly composed of a front rotor 35, compressor rotors 36 and 37, intermediate rotor 38, turbine rotors 39 and 40, fastening bolts 41, nuts 42 and 43, and these parts are on the same axis. It is composed of one piece. Gear couplings 44, 45, 46, 47, and 48 are provided between the front rotor 35, the compressor rotors 36 and 37, the intermediate rotor 38, and the turbine rotors 39 and 40. In the rotor 35 and the turbine rotor 40, the entire rotor is coupled by tightening the fastening bolt 41 and the nuts 42 and 43. The fastening bolt 41 is provided with stepped portions 49, 50, 51, 52, 53, 54, and centering with each rotor is performed by fitting tolerance with each rotor. Pins 55 and 56 are inserted between the nut 42 and the front rotor 35, and between the nut 43 and the turbine rotor 40 to prevent the nut from loosening.

  FIG. 20 is a diagram in which the present invention is applied to a rotor of a gas turbine. In FIG. 20, key grooves are provided in the nuts 43 on the front rotor 35 side and the turbine rotor 40 side of the fastening bolt 41, and keys 57 and 58 are inserted into the key grooves, but the key grooves may be provided in the nut 42. The fastening bolt 41 on the turbine rotor 40 side may be provided. 6 and 7, the number of keys and key grooves may be four or three. After the entire rotor is coupled by the fastening bolt 41 and the nuts 42 and 43, the front rotor 35, the compressor rotors 36 and 37, the intermediate rotor 38, and the turbine rotor are inserted by inserting a key into the fastening bolt 41 and the nuts 42 and 43. 39, 40, the fastening bolt 41, and the nuts 42, 43 are all centered together, and the rotor unbalance related to the eccentricity of the nuts 42, 43 can be reduced. Thereby, since it can align only by the operation | work which inserts a key, an adjustment process can be simplified. Therefore, the assembly time of a rotor can be shortened and a highly reliable gas turbine can be provided.

  Incidentally, by applying the centrifugal compressor rotor of the embodiment shown in FIG. 14 or FIG. 15 to the centrifugal compressor as shown in FIG. 21, a highly stable centrifugal compressor with less vibration can be provided. .

  The fastening member of the present invention is applicable not only to a centrifugal compressor and a rotor of a gas turbine, but also to a rotating body composed of a plurality of rotating body parts.

Schematic showing the fastening bolt and nut tightening structure (when the keyway is on the nut side). The side view and front view of a fastening bolt (when a keyway is on the nut side). The side sectional view and front view of a nut (when a keyway is on the nut side). The perspective view of a key (flat key). The perspective view of a key (curved surface key). Explanatory drawing of a key insertion procedure (when there are four keyways). Explanatory drawing of a key insertion procedure (when there are three keyways). Side surface sectional drawing and front view of a nut (when a keyway is on the nut side, groove addition). Schematic showing the fastening bolt and nut tightening structure (when the keyway is on the fastening bolt side). The side view and front view of a fastening bolt (when a keyway exists in the fastening bolt side). Side surface sectional drawing and front view of a nut (when a keyway is on the fastening bolt side). The perspective view of a key (curved surface key). Centrifugal compressor rotor structure (prior art). The side view which shows a centrifugal compressor rotor structure (this invention, when a keyway exists in a nut side). The side view which shows a centrifugal compressor rotor structure (when this invention, a keyway exists in the fastening bolt side). The side view and front view of a cap (when a keyway is on the nut side). The side view and front view of a cap (when a keyway exists in the fastening bolt side). 1 is a schematic view of a gas turbine to which the present invention is applied. Gas turbine rotor structural drawing (prior art). Schematic which shows the structure (this invention) of a gas turbine rotor. Schematic diagram of a centrifugal compressor.

Explanation of symbols

1, 7, 14, 41 Fastening bolts 2, 8, 15, 42, 43 Nuts 3, 9, 26 Keyway 4, 10, 22, 23, 24, 25 Key 12 Counterweight rotor 13 Compressor rotor 17 Cap 18 Inlay Part 19 Stepped part 28 Compressor 30 Combustor 31 Turbine 32 Generator 33 Rotor

Claims (9)

Fastening bolts and fastening parts for fixing and holding a plurality of rotor parts;
A plurality of keys inserted into a plurality of key grooves disposed in the fastening bolts or screwed portions of the fastening parts so that the fastening bolts and the fastening parts can be centered;
A turbomachine rotor comprising: The turbomachine rotor according to claim 1,
The fastening bolt has a threaded portion composed of a male thread portion provided with a thread and a round bar portion where no thread exists.
The fastening component has a threaded portion that is threadedly engaged with a threaded portion of the fastening bolt that includes a female thread portion provided with a thread and a round hole portion where no thread exists.
A turbomachine rotor comprising the key groove in one of a round bar portion of the fastening bolt and a round hole portion of the fastening part. The turbomachine rotor according to claim 1 or 2,
The turbomachine rotor according to claim 1, wherein there are three or more key grooves, and the key grooves are arranged at equal intervals. The turbomachine rotor according to claim 1,
The turbomachine rotor according to claim 1, wherein the key is a flat key or a curved key having a gradient portion in a key insertion direction. The turbomachine rotor according to claim 1,
A turbomachine rotor, wherein the key, the fastening bolt, and the fastening part are formed with a dimensional tolerance such that the key, the fastening bolt, and the key and the fastening part are an interference fit. The turbomachine rotor according to claim 2,
Has the key groove in the round hole portion of the fastening part,
The round hole portion has a groove portion that forms a gap between the two surfaces on both sides of the surface facing the rod-shaped portion and the inserted key among the surfaces that form the key groove. Features a turbomachine rotor. A compressor that compresses intake air, a combustor that combusts compressed air and fuel compressed by the compressor, a turbine that is driven by combustion gas generated by the combustor, a front rotor, and the compressor In a gas turbine having a compressor rotor, an intermediate rotor, and a gas turbine rotor configured by fixing and holding the turbine rotor constituting the turbine with fastening bolts and nuts,
The fastening bolt has a threaded portion composed of a male thread portion provided with a thread and a round bar portion where no thread exists.
The nut has a threaded portion that is threadedly engaged with a threaded portion of the fastening bolt that is configured by a female thread portion provided with a thread and a round hole portion where no thread exists.
A plurality of keys inserted into a plurality of key grooves disposed in a round bar portion of the fastening bolt or a round hole portion of the nut so that the fastening bolt and the nut can be aligned at the center;
A gas turbine comprising: In a centrifugal compressor having a centrifugal compressor rotor in which a counterweight rotor and a compressor rotor are fixedly held by fastening bolts, nuts, and caps, and a casing that houses the centrifugal compressor rotor,
The counterweight and the compressor rotor have an inlay portion that is fitted and centered with each other,
The fastening bolt includes an end screwed into the counterweight rotor, a stepped portion that fits and aligns with the compressor, a screwed portion into which the nut is screwed, and a screw into which a cap is screwed. One end formed with a joint part, and the threaded part of the fastening bolt has a male thread part provided with a thread and a round bar part where there is no thread,
The screwed portion of the nut and cap has a female screw portion provided with a screw thread and a round hole portion where no screw thread exists,
Either one of the round hole part of the nut and the cap or the round bar part of the fastening bolt has a plurality of key grooves arranged so that a key can be inserted and centered with the fastening bolt.
A centrifugal compressor having a key inserted into the keyway. A turbomachine rotor imbalance correcting method configured by fixing and holding a plurality of rotor parts with fastening bolts and fastening parts,
A key is inserted into a plurality of key grooves provided in either the fastening bolt or the screwing portion of the fastening component, and the eccentric amount of the fastening bolt and the fastening component screwed into the fastening bolt is adjusted. A method for correcting an unbalance of a turbomachine rotor, comprising:

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