JPS6224637B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to an improvement in a casing structure applied to a turbo compressor.

[Conventional technology]

In general, the casing structure of a turbo compressor is provided with a cylindrical body made of a specified material, and leg seats for installation are attached to both sides of the cylindrical body near each end. Each of the flanged nozzles for sucking in and discharging the compressed fluid is arranged in each upper part of the body corresponding to the leg seat position.

The casing structure of a conventional turbo compressor of this type is shown in FIGS. 1a and 1b. Figure a is a partially cutaway side view of the casing, and figure b is a sectional view of the same.

That is, in each of the figures of these conventional examples, reference numeral 1 denotes a cylindrical body, and 2 and 2 denote leg seats attached to both side portions of the cylindrical body 1, respectively, close to both ends.
Reference numerals 3 and 3 designate flanged nozzles attached to the upper parts of the body corresponding to the leg seats 2 and 2, respectively.

Therefore, in the cylindrical body 1, the cross section of the intermediate portion 1a excluding both ends has a predetermined inner diameter D ₀ and a wall thickness t ₀ that maintains normal cylindrical strength, but the influence on the strength of the nozzle hole etc. Thick wall thickness t ₁ (t ₀ <
t _{1 )} , that is, D ₀ +2t ₁ =D ₁ , and the cross section of both ends 1b is the outer diameter D ₂ (D ₁
<D ₂ ), and as described above, each leg seat 2 and each nozzle 3, are welded and attached to each.

[Problem that the invention seeks to solve]

Here, in this conventional structure, the cylindrical body 1
The reason why welding means was employed as described above to attach the leg seats 2, 2 and the nozzles 3, 3 to the base plate is considered to be as follows.

In other words, in the case of high-pressure type casings, it is generally necessary to have a thick wall for strength reasons, so even if mounting methods such as bolting are used, There is no risk of affecting the strength of the bolts, but in the case of medium- and low-pressure type bolts, the wall thickness is relatively thin and it is not possible to tighten them with bolts in this way from the viewpoint of maintaining strength. On the other hand, if these medium-pressure and low-pressure types were given a wall thickness suitable for bolt tightening, the total weight of the entire device would increase, causing various problems, so it would be difficult to make them lighter in weight. This is because it is evaluated as one aspect of technical ability.

However, in this way, when attaching each leg seat 2, 2 and each nozzle 3, 3 to the cylindrical body 1,
When using a conventional structure that uses welding means, unlike the case where mounting means are bolted,
The manufacturing process involves welding, which increases the number of steps.

For example, when installing by welding, it is necessary to carry out so-called non-destructive inspection using radiation irradiation after welding and rework based on the inspection results, annealing treatment, shot blasting, etc. This method not only increases the number of steps, but also makes it difficult to obtain the desired strength calculated in advance, resulting in a lack of reproducibility and reliability.

[Means for solving problems]

This invention was made in view of these circumstances, and provides a casing structure for a turbo compressor that can suppress an increase in the weight of the casing even when the leg seat and nozzle are attached with bolts. . The casing structure according to the present invention makes the inner diameter center of the cylindrical body eccentric downward with respect to the outer diameter center, and provides counterbore surfaces spaced apart in the axial direction on both sides and the upper part of the cylindrical body,
The leg seat and nozzle are attached to these counterbore surfaces with bolts.

[Effect]

In this invention, the leg seat and the nozzle are attached with bolts to a thick portion formed by making the center of the inner diameter of the cylindrical body eccentric with respect to the center of the outer diameter.

〔Example〕

Hereinafter, one embodiment of the casing structure according to the present invention will be described in detail with reference to FIGS. 2a and 2b.

FIGS. 2a and 2b show a casing according to this embodiment structure corresponding to FIGS. 1a and 1b, and in these FIGS.
is a cylindrical body, 12, 12 is this cylindrical body 11
Each leg seat 13, 13 is attached to each side portion near each end of the leg seat 12, 12.
Each flanged nozzle is attached to each upper part of the fuselage corresponding to the following.

Therefore, in the case of this embodiment structure, the intermediate main body portion 11a serving as the main body portion of the cylindrical body 11 is
The inner diameter D ₀ is set _to be the same as in the case of the conventional example, and the interval _{t 1 -} Outer diameter center O ₁ eccentric upward by t ₀
The outer diameter _D1 is the same as that of the conventional example. In other words, the center of the inner diameter of the cylindrical body 11
O ₀ is offset downward by an interval t ₁ -t ₀ with respect to the outer diameter center O ₁ , and the wall thickness at the upper part is thicker than that at the lower part. In addition, this intermediate main body portion 11
Both ends 11b, 11b gently connected to a
, the center of the inner diameter is the same as in the conventional example.
It has an outer diameter D ₂ due to O ₀ , and is thus configured to have an eccentric cylindrical shape at the intermediate main body and a concentric cylindrical shape at both ends.

That is, in this cylindrical body 11, the cross-sectional thickness of the intermediate main body portion 11a to which each leg seat 12, 12 and each nozzle 13, 13 are attached is as large as the lower part.
It is formed into an eccentric cylindrical cross-section with a width of t ₀ , which gradually becomes thicker toward the top corresponding to the eccentric spacing t ₁ -t ₀ , and a width of 2t ₁ -t ₀ on the upper side.

Further, the cylindrical body 11 is provided with counterbore surfaces 14, 14 spaced apart in the axial direction from each other on both sides of the cylindrical body 11, which are located close to both ends of the cylindrical body 11. Counterbore surfaces 15, 15 are formed in the counterbore surfaces 15, 15, and the wall thickness at each of these counterbore surfaces 14, 14 and 15, 15, especially the wall thickness at the counterbore surfaces 15, 15 for nozzle installation, is as follows. , this is made to be equal to or greater than the wall thickness t ₁ set as the predetermined strength.

Next, for the cylindrical body 11 in which each part is formed as described above, counterbore surfaces 1 on both sides of the body 11 are formed.
4, 14, the mounting flanges 12a, 12a of the respective leg seats 12, 12 are attached and fixed by bolts 16, 16, and the counterbore surfaces 15, 15 of the upper portions are provided with the respective flanges. The mounting flanges 13a, 13a of the nozzles 13, 13 are fixed by bolts and nuts 17, 17. In addition, in this example figure, 18 is
The flanged nozzles and their mounting nozzle holes extending through the body are shown.

Therefore, in the case of the casing structure according to this embodiment, the thickness of the cross section forming the intermediate main body portion 11a of the cylindrical body 11 is the same as that of the attached members, that is, each leg seat 12, 12 and each nozzle 13,
The wall thickness is sufficient to satisfy the normal cylindrical strength on the lower half side where there is no need to attach No. 13, and the wall thickness is made to satisfy the normal cylindrical strength without affecting the casing strength on both side sections where attachment members need to be attached and on the upper half side. In addition, the wall thickness can be increased to a level that allows mounting and fixing by tightening the respective bolts.

〔Effect of the invention〕

As explained above, according to the present invention, the center of the inner diameter of the cylindrical body is eccentrically downward with respect to the center of the outer diameter, and counterbore surfaces spaced apart in the axial direction are provided on both sides and the upper part of the cylindrical body, Since the leg seat and nozzle were attached to these counterbore surfaces with bolts,
The leg seats and the nozzle are attached with bolts to a thick portion formed by eccentrically centering the inner diameter center of the cylindrical body with respect to the outer diameter center.

Therefore, since it is possible to suppress the increase in the outer diameter of the cylindrical body due to the provision of the part into which the bolt is screwed, the weight of the casing can be reduced by welding even if the leg seat and nozzle are attached with bolts. The relative increase can be suppressed compared to the structure where

[Brief explanation of the drawing]

Figures 1a and 1b are partially cutaway side views showing a conventional casing structure;
2 is a sectional view taken along line b-1b, and FIGS. 2a and 2b are partially cutaway side views showing a casing structure to which an embodiment of the present invention is applied, and a cross-sectional view taken along line bb-b. It is a diagram. DESCRIPTION OF SYMBOLS 11... Cylindrical body of casing, 11a... Intermediate main part of cylindrical body, 11b... Both ends of cylindrical body, 12... Leg seat for installation, 12a... Mounting flange of leg seat, 13... Suction of compressed fluid , discharge nozzle, 13a... nozzle mounting flange, 14...
Counterbore surface for attaching the leg seat, 15... Counterbore surface for attaching the nozzle, 16, 17... Bolts and nuts for attachment. D ₀ ...Inner diameter of intermediate main body part, O ₀ ...Center of inner diameter, D ₁
...Outer diameter of the intermediate main body part, O ₁ ...Outer diameter center, t ₀ ...Normal cylindrical strength-maintaining wall thickness, t ₁ ...Wall thickness considering the influence of nozzle holes, etc., t ₁ - _{t 0} ... Eccentric spacing, D ₂ ...Outer diameter of both ends.

Claims (1)

[Claims] 1. In a turbo compressor casing in which leg seats 12, 12 are provided on both sides of a cylindrical body 11, and nozzles 13, 13 are provided in the upper part for sucking in and discharging fluid to be compressed, the inner diameter of the cylindrical body 11 is The center is eccentrically downward with respect to the outer diameter center, and countersunk surfaces 14 and 15 are provided on both sides and the top of the cylindrical body 11 and are spaced apart in the axial direction. A casing structure for a turbo compressor characterized in that a nozzle 13 is attached with bolts 16 and 17.