KR20180096998A - Integrally Geared Compressor - Google Patents

Abstract

According to an embodiment of the present invention, a centrifugal compressor comprises: a power generation unit generating rotation power; a bull shaft receiving the rotation power from the power generation unit; a bull gear setting the bull shaft as a rotation shaft and rotating in accordance with the rotation of the bull shaft; a pinion gear engaged to the bull gear and rotating in accordance with the rotation of the bull gear; a pinion shaft acting as a rotation shaft of the pinion gear and rotating in accordance with the rotation of the pinion gear; an impeller stage having an impeller formed on one end of the pinion shaft and rotating in accordance with the rotation of the pinion shaft and shroud covering the impeller; and a stopper assembled with the pinion shaft and fixed to a gearbox, in which the bull gear and the pinion gear are installed.

Description

A centrifugal compressor {Integrally Geared Compressor}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal compressor, and more particularly, to a centrifugal compressor that prevents a clearance between an impeller and a shroud from increasing due to a stopper being installed on a pinion shaft even when a thrust is generated in a part of an impeller stage, .

Generally, a compressor is a high pressure fluid compression device that increases the pressure by compressing a fluid such as air and has a compression ratio (discharge pressure ratio to suction pressure) of a certain value or more. Such a compressor receives power from a power generating device such as an electric motor or a turbine, compresses a fluid such as air, a refrigerant or other gas, and supplies the compressed fluid at a high pressure. The compressor compresses an air compressor or an air conditioner It is widely used. Compressors can be classified into reciprocating type by piston reciprocating motion, rotary type by special type of rotating body, centrifugal type by centrifugal force of wing, axial flow type by using axial thrust of wing etc. .

Hereinafter, a conventional centrifugal compressor (Integrally Geared Compressor) will be briefly described with reference to FIG.

1 is a schematic diagram of a conventional centrifugal compressor 2;

The conventional centrifugal compressor 2 is an apparatus for compressing a fluid by applying a centrifugal force to the fluid using an impeller 27 that performs rotational motion. In particular, as shown in FIG. 1, a plurality of impeller stages 26 are provided for gearing to compress the fluid to a high compression ratio.

As an example of the centrifugal compressor 2 shown in FIG. 1, a four-stage compressor having four impeller stages 26a, 26b, 26c, and 26d may be formed. At this time, thrusts due to the rotation of the plurality of impellers 27 are generated in the longitudinal direction of the pinion shaft 25, respectively. Specifically, thrusts generated in the first and second impeller stages 26a and 26b act in the direction of the first pinion shaft 25a, and thrusts generated in the third and fourth impeller stages 26c and 26d act in the direction of the first pinion shaft 25a. 2 pinion shaft 25b. 1, when the thrust acts in the direction in which the first impeller stage 26a and the fourth impeller stage 26d are formed, the first and second pinion gears 24a and 24b, The gear 23 is tilted. Then, the first and second pinion shafts 25a and 25b move finely in the direction in which the thrust acts. A clearance is generated between the second and third impellers 27b and 27c and the second and third shrouds 28b and 28c in the second impeller stage 26b and the third impeller stage 26c . This clearance lowers the compression efficiency, and tilting of the bull gear 23 may occur, causing deformation of the gear. And there is a problem that a coupling failure occurs between the bull gear 23 and the pinion gear 24, thereby decreasing the durability of the compressor.

In order to solve this problem, a technique for installing a thrust bearing has been proposed. Thrust bearings are bearings used when the thrust acts in the axial direction. However, when thrust bearings are installed, the number of parts of the centrifugal compressor as a whole increases, resulting in an increase in cost. In addition, there is a problem that the structure is complicated, the design is not easy, the risk of failure is increased, and the service life is shortened.

Korean Laid-Open Publication No. 2015-0140320 Korean Laid-Open Publication No. 2013-0001221

A problem to be solved by the present invention is to provide a centrifugal compressor that prevents a clearance between an impeller and a shroud from being increased by providing a stopper on a pinion shaft even when thrust is generated in a part of the impeller stage and the bull gear is tilted .

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a centrifugal compressor including: a power generating unit generating a rotational power; A fire shaft receiving the rotational power from the power generating unit; A bull gear which rotates together with the rotation shaft of the bull shaft and serves as a rotation shaft; A pinion gear engaged with the bull gear and rotated together with the rotation of the bull gear; A pinion shaft which serves as a rotation shaft of the pinion gear and rotates together with the rotation of the pinion gear; An impeller stage formed at one end of the pinion shaft, the impeller stage including an impeller rotating together with rotation of the pinion shaft and a shroud covering the impeller; And a stopper assembled to the pinion shaft and fixed to the gear box in which the bull gear and the pinion gear are installed.

Other specific details of the invention are included in the detailed description and drawings.

The embodiments of the present invention have at least the following effects.

It is possible to prevent the clearance between the impeller and the shroud from increasing due to the provision of the stopper on the pinion shaft even if thrust is generated in some of the impeller stages and the bull gear is tilted.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the specification.

1 is a schematic diagram of a conventional centrifugal compressor.
2 is a schematic block diagram of a centrifugal compressor according to an embodiment of the present invention.
Fig. 3 is an enlarged view of the area R in Fig. 2 enlarged.
4 is a perspective view of a stopper according to an embodiment of the present invention.
5 is a perspective view showing a stopper according to an embodiment of the present invention assembled to a pinion shaft.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. The terms " comprises "and / or" comprising "used in the specification do not exclude the presence or addition of one or more other elements in addition to the stated element.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a schematic diagram of a centrifugal compressor 1 according to an embodiment of the present invention, and FIG. 3 is an enlarged view of an enlarged R region of FIG.

2, the centrifugal compressor 1 according to an embodiment of the present invention includes a power generating unit 11 for generating power, a plurality of gears meshed with each other to transmit the generated power, A plurality of shafts for transmitting the power, a plurality of impeller stages (16) for receiving the power and compressing the fluid, a stopper (19) for preventing the tilting of the plurality of gears, and a plurality of shafts And a gear box 10 installed inside.

The power generating section 11 generates a rotational power to cause the impeller 17 to rotate. At this time, the power generating unit 11 receives a different power from the outside and generates rotational power. The power generating portion 11 may be variously formed as long as it can generate unrestricted rotational power, such as an internal combustion engine such as a gas turbine, an electric motor using electric power, and the like.

The plurality of gears includes a bull gear (13) and a plurality of pinion gears (14). In the example shown in Fig. 2, two pinion gears 14 are formed. The bull gear 13 and the pinion gear 14 may each be a helical gear having a tooth profile formed to be inclined from the rotational axis. In the case of a helical gear, the inclined directions of the teeth are opposite to each other so that the bull gear 13 and the respective pinion gears 14 can be easily engaged with each other and rotated. However, the present invention is not limited to this, and may be various gears such as a spur gear whose tooth profile is formed in parallel with the rotating shaft.

The plurality of shafts include a pin shaft (pinion shaft) 15 serving as a rotary shaft of the pinion gear 14 and a bull shaft 12 serving as a rotary shaft of the bull gear 13. 2, since the number of the pinion gears 14 is two, two pinion shafts 15 are also formed.

A plurality of impeller stages 16 are formed on the both ends of the pinion shaft 15, respectively, so as to compress and discharge the inflow fluid. For example, in the centrifugal compressor 1 shown in FIG. 2, a four-stage compressor having four impeller stages 16 may be formed. The impeller stage 16 reduces the dynamic pressure component of the fluid discharged from the impeller 17 rotating together with the rotation of the pinion shaft 15, the scroll supporting the impeller 17, And a shroud 18 which forms an inner space through which the fluid flows and which covers the impeller 17, and a shroud 18 which cooperates with the scroll to form an inner space through which the fluid flows.

The impeller 17 uses the rotational power transmitted from the pinion shaft 15 to increase the pressure of the fluid. The impeller 17 may be a radial impeller having an inlet port formed in the axial direction and a discharge port formed in the radial direction.

The impeller 17 is provided at each end of the pinion shaft 15, respectively. 2, the first impeller stage 16a and the second impeller stage 16b are respectively provided at both ends of the first pinion shaft 15a, and the third impeller stage 16c and the fourth impeller stage 16b are provided at both ends of the first pinion shaft 15a, The impeller stage 16d is installed at both ends of the second pinion shaft 15b. That is, a pair of impeller stages 16 are supported by a common pinion shaft 15. [

Although the four impeller stages 16 are shown in FIG. 2, the centrifugal compressor 1 according to an embodiment of the present invention is not limited, and various numbers of impeller stages 16 may be formed. The impeller stage 16 may be provided with an odd number of teeth. In this case, one of the plurality of pinion shafts 15 may support only one impeller stage 16 at one end. In order to balance the weight with the impeller stage 16, a balance weight may be provided at the other end.

First and second pinion gears 14a and 14b are formed at the centers of the first and second pinion shafts 15a and 15b, respectively. On the other hand, the power generating portion 11 is provided at one end of the bull shaft 12, and the bull gear 13 is provided at the other end of the bull shaft 12. The first and second pinion gears 14a and 14b are respectively engaged with one bull gear 13. When the power generating portion 11 generates rotational power, the bull gear 13 rotates while the bull shaft 12 rotates. ) Together. The first and second pinion gears 14a and 14b are rotated and the first and second pinion shafts 15a and 15b are rotated to rotate the first to fourth impeller stages 16a to 16d The first to fourth impellers 17a, 17b, 17c, and 17d included therein are rotated. Therefore, the power generating section 11 rotates the bull gear 13, the pinion gear 14, and the pinion shaft 15 at the same time, respectively, so that the impellers 17 rotate to multi-stage the air.

As described above, when the centrifugal compressor 1 is operated, thrusts due to the rotation of the plurality of impellers 17 are generated in the longitudinal direction of the pinion shaft 15, respectively. Specifically, the flow rate of the fluid flowing in and out of each of the plurality of impeller stages 16, the rotating speed of the impeller 17, the radius of the impeller 17, and the like are different. This is because the fluid is compressed step by step through the plurality of impeller stages 16, respectively. For example, when the fluid introduced into the fourth impeller stage 16d is compressed and discharged under the first pressure, it flows into the third impeller stage 16c. When the fluid is compressed and discharged under a second pressure larger than the first pressure, it flows into the second impeller stage 16b. When the fluid is compressed and discharged under a third pressure larger than the second pressure, it flows into the first impeller stage 16a. Then, it is compressed and discharged by receiving a fourth pressure larger than the third pressure. The fluid can thus be compressed to a fourth pressure, which is ultimately a very large pressure.

In order to make the magnitude of the pressure acting on each of the plurality of impeller stages 16 different from each other, the flow rate of the fluid flowing in and out of each of the plurality of impeller stages 16, the rotational speed of the impeller 17, And the like. By multiplying the magnitude of this pressure by the area of the rotor of the impeller 17 under pressure, a thrust is generated. 1, the thrust generated in the first and second impeller stages 16a and 16b acts in the direction of the first pinion shaft 15a and the thrust generated in the third and fourth impeller stages 16c and 16d, The thrust generated in the second pinion shaft 15b acts in the direction of the second pinion shaft 15b. At this time, if the thrust acts on the thrust in the direction in which the first impeller stage 16a and the fourth impeller stage 16d are formed, as shown in Fig. 1, the first and second pinion gears 14a And 14b are tilted. Then, the first and second pinion shafts 15a and 15b move finely in the direction in which the thrust acts.

The first and fourth impellers 17a and 17d and the first and fourth shrouds 18a and 18d may contact each other in the first impeller stage 16a and the fourth impeller stage 16d. Therefore, all of the first to fourth impeller stages 16a, 16b, 16c, and 16d are designed to have a certain distance between the impeller 17 and the shroud 18 from the beginning.

This gap is also present in the second impeller stage 16b and the third impeller stage 16c. When the thrust acts in the direction in which the first impeller stage 16a and the fourth impeller stage 16d are formed, the second and third impellers 17b and 17c and the second and third shrouds 18b, and 18c, a clearance greater than the designed spacing is generated. This clearance lowers the compression efficiency and tilting of the bull gear 13 may cause the gear to be deformed and a coupling failure may occur between the bull gear 13 and the pinion gear 14 resulting in poor durability of the compressor .

Accordingly, the centrifugal compressor 1 according to an embodiment of the present invention further includes a stopper 19, as shown in FIGS. The stopper 19 is formed on the first or second pinion shaft 15a or 15b. In particular, as shown in Figs. 2 and 3, it is preferable to be formed in the vicinity of the pinion gear 14. 2, a stopper 19 according to an embodiment of the present invention is illustrated as being formed on the first pinion shaft 15a, but it is not limited thereto and may be formed on the second pinion shaft 15b, 2 pinion shafts 15a and 15b, respectively. Furthermore, a total of four gears may be formed in front of and behind the first pinion gear 14a and one before and after the second pinion gear 14b. That is, if the thrust prevents the clearance between the impeller 17 and the shroud 18 from increasing further than the original spacing, the stopper 19 can be formed in various numbers.

FIG. 4 is a perspective view of a stopper 19 according to an embodiment of the present invention, and FIG. 5 is a perspective view showing a state where a stopper 19 according to an embodiment of the present invention is assembled to a pinion shaft 15. FIG.

As shown in FIG. 4, the stopper 19 according to an embodiment of the present invention may have a round disc shape. A rounded hole may be formed in the center of the stopper 19. The pinion shaft 15 can be inserted into the hole formed in the stopper 19 and assembled. Therefore, it is preferable that the inner diameter of the stopper 19 has a size corresponding to the diameter of the pinion shaft 15 so that the pinion shaft 15 can be easily inserted.

The stopper 19 is installed in the gear box 10 after the pinion shaft 15 is inserted. At this time, as shown in FIG. 4, a plurality of fastening holes may be recessed at predetermined intervals along the circumferential direction of the stopper 19 so as to be fixed to the gear box 10. When the stopper 19 is installed in the gear box 10, a plurality of fastening portions may be formed in the gear box 10 so as to be inserted into the plurality of fastening holes. In this case, the plurality of fastening portions are preferably formed to correspond to the number, spacing, and size of the plurality of fastening holes. However, the present invention is not limited to this, and a coupling tool such as a bolt or a rivet may be coupled to the coupling hole. That is, various methods can be used if the stopper 19 can be fixed to the gear box 10.

The stopper 19 is preferably formed in the vicinity of the pinion gear 14 in the pinion shaft 15 as described above. 5, a thrust collar 151 for supporting the first pinion gear 14a or the second pinion gear 14b, and a radial bearing (not shown) for supporting a load acting in a direction perpendicular to the shaft, Bearing 152, as shown in Fig. Therefore, since the pinion shaft 15 can be fixed to the stopper 19, it is possible to prevent the pinion shaft 15 from sliding in a state where the pinion shaft 15 is inserted into the stopper 19. [

The stopper 19 is more durable and wear resistant than the gear box 10. That is, the stopper 19 is made of a material having higher strength and hardness than the gear box 10 such as stainless steel, titanium, and the like. Accordingly, the centrifugal compressor 1 according to the embodiment of the present invention can prevent the increase of the clearance more effectively and prolong the life span of the pinion shaft 15, as compared with the case where the gear box 10 itself fixes the pinion shaft 15. [ have.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

1: Centrifugal compressor
11:
12: Fire shaft
13: bull gear
14: Pinion gear
15: Pinion shaft
16: Impeller stage
17: Impeller
18: Shuraud
19: Stopper
151: Thrust collar
152: Radial bearing

Claims (3)

A power generator for generating a rotational power;
A fire shaft receiving the rotational power from the power generating unit;
A bull gear which rotates together with the rotation shaft of the bull shaft and serves as a rotation shaft;
A pinion gear engaged with the bull gear and rotated together with the rotation of the bull gear;
A pinion shaft which serves as a rotation shaft of the pinion gear and rotates together with the rotation of the pinion gear;
An impeller stage formed at one end of the pinion shaft, the impeller stage including an impeller rotating together with rotation of the pinion shaft and a shroud covering the impeller; And
And a stopper that is assembled to the pinion shaft and is installed to be fixed to a gear box in which the bull gear and the pinion gear are installed. The method according to claim 1,
The stopper
A thrust collar for supporting the pinion gear, and a radial bearing for enduring a load acting in a direction perpendicular to the axial direction of the pinion shaft. The method according to claim 1,
The stopper
And has a hardness greater than the hardness of the gearbox.

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