JP7284045B2 - Fluid machinery - Google Patents

Description

The present invention relates to a fluid machine having a screw rotor.

An air compressor, which is an example of a fluid machine, includes, for example, a pair of male and female screw rotors, and a casing that accommodates the screw rotors and forms compression chambers (working chambers) together with tooth grooves of the screw rotors. The compression chamber moves in the axial direction of the screw rotor as the screw rotor rotates, and performs an intake process of sucking air through an intake port on one side in the axial direction, a compression process of compressing air, and a compression process on the other side in the axial direction. A discharge process of discharging compressed air through the discharge port is sequentially performed. Since compression heat is generated in the compression process, the air temperature rises and the screw rotor and the like are heated and thermally expanded. Therefore, in order to suppress the thermal expansion of the screw rotor, a technology for cooling the screw rotor has been proposed (see, for example, Patent Document 1).

The screw rotor includes a tooth portion having tooth grooves, a suction side shaft portion extending outward from the suction side end surface of the tooth portion, and a discharge side shaft portion extending outward from the discharge side end surface of the tooth portion. It is configured. The tooth portion, the suction-side shaft portion, and the discharge-side shaft portion of the screw rotor described in Patent Document 1 have through holes extending in the axial direction. is now in circulation.

JP 2006-097604 A

In Patent Document 1, the axial distribution of the cooling force of the cooling liquid at the discharge-side shaft portion of the screw rotor is not taken into consideration. More specifically, the through hole of the discharge-side shaft portion has the same radial cross-sectional shape and the same circumferential length at any portion in the axial direction. Therefore, the axial distribution of the cooling force of the coolant flowing through the through hole of the discharge-side shaft portion is uniform. However, generally, a discharge-side air seal and a discharge-side bearing are provided on the outer peripheral side of the discharge-side shaft portion, and hot compressed air flows into the discharge-side air seal. Therefore, a portion of the discharge-side shaft in the axial direction (more specifically, a portion including a range corresponding to the discharge-side air seal and a range from the discharge-side air seal to the discharge-side end face of the tooth) enhances the cooling power of the coolant. However, the remaining axial portion of the discharge-side shaft portion (specifically, the portion including the range corresponding to the discharge-side bearing) does not require as much cooling power.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and one of the objects thereof is to improve the cooling efficiency by the axial distribution of the cooling force of the coolant flowing through the through holes of the screw rotor. .

In order to solve the above problems, the configurations described in the claims are applied. The present invention includes a plurality of means for solving the above-described problems. To give an example, a screw rotor and a casing housing the screw rotor and forming a compression chamber together with tooth grooves of the screw rotor are provided. a suction-side bearing and a discharge-side bearing that rotatably support the screw rotor; and a discharge-side seal that is disposed between the compression chamber and the discharge-side bearing and suppresses leakage of compressed gas from the compression chamber. The screw rotor includes a tooth portion in which the tooth spaces are formed, a suction-side shaft portion extending outward from the suction-side end surface of the tooth portion, and an outer side extension from the discharge-side end surface of the tooth portion. The tooth portion, the suction-side shaft portion, and the discharge-side shaft portion of the screw rotor each have a through hole extending in the axial direction, and the coolant flows through the through hole. In a fluid machine configured to circulate, a part of the axial direction consisting of a range corresponding to the discharge side seal of the discharge side shaft portion and a range from the discharge side seal to the discharge side end surface of the tooth portion is greater than the circumferential length of the radial cross section of the through hole in the remaining portion of the discharge-side shaft portion other than the axial portion of the tooth portion. The peripheral length of the radial cross-section of the through hole in a portion of the axial direction, which is a range from the discharge side end surface of the tooth portion to 3/4 or less of the axial length of the tooth portion, is equal to the shaft of the tooth portion. greater than the perimeter of the radial cross-section of the through-hole in the rest of the direction.

According to the present invention, the cooling efficiency can be improved by the axial distribution of the cooling force of the coolant flowing through the through hole of the screw rotor.

Problems, configurations, and effects other than those described above will be clarified by the following description.

1 is a horizontal sectional view showing the structure of an air compressor according to a first embodiment of the invention; FIG. FIG. 2 is a vertical cross-sectional view taken along line II-II in FIG. 1; 1 is an external view showing the structure of a male rotor in the first embodiment of the invention; FIG. FIG. 3 is an axial cross-sectional view showing the structure of the male rotor in the first embodiment of the present invention; FIG. 4 is a radial cross-sectional view of the discharge-side shaft portion taken along the arrow VV in FIG. 3; FIG. 4 is a radial cross-sectional view of the discharge-side shaft portion taken along the arrow VI-VI in FIG. 3; FIG. 3 is an external view showing the structure of the female rotor in the first embodiment of the present invention; FIG. 2 is an axial cross-sectional view showing the structure of the female rotor in the first embodiment of the present invention; FIG. 6 is a radial cross-sectional view of a discharge-side shaft portion in a first modified example of the invention, corresponding to FIG. 5 ; FIG. 6 is a radial cross-sectional view of a discharge-side shaft portion in a second modification of the invention, corresponding to FIG. 5 ; FIG. 6 is a radial cross-sectional view of a discharge-side shaft portion in a third modification of the invention, corresponding to FIG. 5 ; FIG. 5 is an axial cross-sectional view showing the structure of a male rotor in a second embodiment of the invention; FIG. 6 is an axial cross-sectional view showing the structure of a female rotor in a second embodiment of the invention;

A first embodiment in which the present invention is applied to an air compressor will be described with reference to the drawings.

First, the structure of the air compressor of this embodiment will be described. FIG. 1 is a horizontal cross-sectional view showing the structure of an air compressor according to this embodiment, and FIG. 2 is a vertical cross-sectional view taken along line II-II in FIG.

The air compressor of this embodiment comprises a male rotor 1A and a female rotor 1B, which are screw rotors, and a casing 2 that accommodates the male rotor 1A and the female rotor 1B and forms compression chambers (working chambers) in tooth grooves thereof. Prepare.

As the male rotor 1A and the female rotor 1B rotate, the compression chamber moves from one axial side (left side in FIGS. 1 and 2) to the other axial side (right side in FIGS. 1 and 2). An intake process in which air (gas) is sucked in through the intake port (opening) on one side, a compression process in which the air is compressed, and a discharge process in which compressed air is discharged through the discharge port (opening) on the other side in the axial direction. conduct. The air compressor of this embodiment is of a non-liquid supply type (specifically, one that does not supply liquid such as oil or water to the working chamber). Therefore, the temperature of the compressed air is higher than in the case of the liquid supply type (specifically, the case in which liquid such as oil or water is supplied to the working chamber).

As shown in FIG. 3, which will be described later, the male rotor 1A has a tooth portion 3A in which tooth spaces are formed, and extends outward (to the left in FIGS. 1, 2, and 3) from the suction side end surface of the tooth portion 3A. and a discharge-side shaft portion 5A extending outward (to the right in FIGS. 1, 2, and 3) from the discharge-side end surface of the tooth portion 3A. integrally formed by As shown in FIGS. 1 and 2, the male rotor 1A includes a suction side bearing 6A arranged on the outer peripheral side of the suction side shaft portion 4A and a plurality of discharge side bearings arranged on the outer peripheral side of the discharge side shaft portion 5A. 7A is rotatably supported.

As shown in FIG. 7, which will be described later, the female rotor 1B has a tooth portion 3B in which tooth spaces are formed, and extends outward (to the left in FIGS. 1, 2, and 7) from the suction side end surface of the tooth portion 3B. and a discharge-side shaft portion 5B extending outward (to the right in FIGS. 1, 2, and 7) from the discharge-side end surface of the tooth portion 3B. integrally formed by As shown in FIGS. 1 and 2, the female rotor 1B includes a suction side bearing 6B arranged on the outer peripheral side of the suction side shaft portion 4B and a plurality of discharge side bearings arranged on the outer peripheral side of the discharge side shaft portion 5B. 7B is rotatably supported.

A tip side portion of the suction side shaft portion 4A of the male rotor 1A protrudes from the casing 2 and is provided with a pinion gear 8. As shown in FIG. The pinion gear 8 is connected to the rotating shaft of the motor via, for example, a gear mechanism and a belt mechanism (not shown). Male rotor 1A is rotated by transmission of the rotational force of the motor to male rotor 1A via pinion gear 8, gear mechanism, and belt mechanism.

Timing gears 9A and 9B are provided on the discharge side shaft portion 5A of the male rotor 1A and the discharge side shaft portion 5B of the female rotor 1B, respectively, and the timing gears 9A and 9B are meshed with each other. The rotational force of the male rotor 1A is transmitted to the female rotor 1B via the timing gears 9A, 9B, thereby rotating the female rotor 1B. As a result, the male rotor 1A and the female rotor 1B rotate so as to mesh with each other without contact.

A suction side air seal 10A and a suction side oil seal 11A are provided on the outer peripheral side of the suction side shaft portion 4A of the male rotor 1A (more specifically, between the compression chamber and the suction side bearing 6A). A suction side air seal 10B and a suction side oil seal 11B are provided on the outer peripheral side of the suction side shaft portion 4B of the female rotor 1B (more specifically, between the compression chamber and the suction side bearing 6B). The suction side air seals 10A and 10B suppress air leakage from the compression chambers, and the suction side oil seals 11A and 11B suppress lubricant leakage from the suction side bearings 6A and 6B.

A discharge-side air seal 12A and a discharge-side oil seal 13A are provided on the outer peripheral side of the discharge-side shaft portion 5A of the male rotor 1A (more specifically, between the compression chamber and the discharge-side bearing 7A). A discharge-side air seal 12B and a discharge-side oil seal 13B are provided on the outer peripheral side of the discharge-side shaft portion 5B of the female rotor 1B (more specifically, between the compression chamber and the discharge-side bearing 7B). The discharge side air seals 12A and 12B suppress leakage of compressed air from the compression chambers, and the discharge side oil seals 13A and 13B suppress leakage of lubricating oil from the discharge side bearings 7A and 7B.

Next, the structure of the male rotor of this embodiment will be described. FIG. 3 is an external view showing the structure of the male rotor in this embodiment. FIG. 4 is an axial sectional view showing the structure of the male rotor in this embodiment. 5 is a radial cross-sectional view along arrow VV in FIG. 3, and FIG. 6 is a radial cross-sectional view along arrow VI-VI in FIG.

The tooth portion 3A, the suction-side shaft portion 4A, and the discharge-side shaft portion 5A of the male rotor 1A have axially extending through holes 14A, 15A, and 16A. communicate with each other. Then, for example, a cooling liquid (more specifically, oil or water) from a liquid supply system (not shown) flows into the through hole 15A through the opening in the end face of the suction side shaft portion 4A, and flows into the through holes 15A, 14A, 16A, and flows out from the through-hole 16A through the opening in the end face of the discharge-side shaft portion 5A.

In this embodiment, the through hole 14A of the tooth portion 3A, the through hole 15A of the suction side shaft portion 4A, and the through hole 16A of the discharge side shaft portion 5A have a circular cross section in the axial direction. is. The diameter of the through hole 14A of the tooth portion 3A in most of the axial direction (more specifically, the portion of the tooth portion 3A excluding the vicinity of the discharge side end surface) is the diameter of the through hole 15A of the suction side shaft portion 4A. is the same as

As a major feature of this embodiment, a portion A1 in the axial direction of the through hole 16A of the discharge side shaft portion 5A (more specifically, the range corresponding to the discharge side air seal 12A and the discharge side of the tooth portion 3A from the discharge side air seal 12A). The diametrical dimension of the portion including the range up to the end surface) is larger than the diametrical dimension of the remaining portion A2 in the axial direction (specifically, the portion including the range corresponding to the discharge side bearing 7A). Therefore, the circumferential length of the radial cross section of the through hole 16A of the discharge-side shaft portion 5A (see FIG. 5) in the axial portion A1 is equal to the circumferential length of the radial cross section of the remaining axial portion A2 (see FIG. 6). reference) is larger. As a result, the cooling power of the coolant in the relatively high temperature portion A1 can be enhanced, while the cooling power of the coolant in the relatively low temperature portion A2 can be suppressed. Therefore, the cooling efficiency can be improved by the axial distribution of the cooling power of the coolant. Moreover, the cooling effect of the discharge side portion of the tooth portion 3A can be enhanced due to the thermal conductivity with the discharge side shaft portion 5A.

In this embodiment, the diameter of the remaining axial portion A2 of the through hole 15A of the discharge side shaft 5A is the same as the diameter of the through hole 14A of the suction side shaft 4A. In this embodiment, the axial portion A1 includes a range corresponding to the entire discharge side air seal 12A, but may include a range corresponding to a portion of the discharge side air seal 12A.

Next, the structure of the female rotor of this embodiment will be described. FIG. 7 is an external view showing the structure of the female rotor in this embodiment. FIG. 8 is an axial sectional view showing the structure of the female rotor in this embodiment.

The tooth portion 3B, the suction-side shaft portion 4B, and the discharge-side shaft portion 5B of the female rotor 1B have axially extending through holes 14B, 15B, and 16B. communicate with each other. Then, for example, the coolant from the liquid supply system flows into the through hole 15B through the opening in the end face of the suction side shaft portion 4B, flows through the through holes 15B, 14B, and 16B in order, and flows through the end face of the discharge side shaft portion 5B. through the opening of the through hole 16B.

In this embodiment, the through-hole 14B of the tooth portion 3B, the through-hole 15B of the suction-side shaft portion 4B, and the through-hole 16B of the discharge-side shaft portion 5B all have circular cross sections in the axial direction. is. The diameter of most of the through hole 14B of the tooth 3B in the axial direction (specifically, the portion of the tooth 3B excluding the vicinity of the discharge side end face) is the same as the diameter of the through hole 15B of the suction side shaft 4B. is the same as

As a major feature of this embodiment, a portion B1 in the axial direction of the through hole 16B of the discharge side shaft portion 5B (more specifically, the range corresponding to the discharge side air seal 12B and the discharge side of the tooth portion 3B from the discharge side air seal 12B). The diameter of the portion including the range up to the end face) is larger than the diameter of the remaining portion B2 in the axial direction (more specifically, the portion including the range corresponding to the discharge side bearing 7B). Therefore, the circumferential length of the radial cross section of the through hole 16B of the discharge side shaft portion 5B at the axial portion B1 is larger than the circumferential length of the radial cross section of the remaining axial portion B2. As a result, the cooling power of the coolant in the relatively high temperature portion B1 can be enhanced, while the cooling power of the coolant in the relatively low temperature portion B2 can be suppressed. Therefore, the cooling efficiency can be improved by the axial distribution of the cooling power of the coolant. Moreover, the cooling effect of the discharge side portion of the tooth portion 3B can be enhanced due to the thermal conductivity with the discharge side shaft portion 5B.

In this embodiment, the diameter of the remaining portion B2 in the axial direction of the through hole 15B of the discharge side shaft 5B is the same as the diameter of the through hole 14B of the suction side shaft 4B. Further, in the present embodiment, the axial portion B1 includes a range corresponding to the entire discharge side air seal 12B, but may include a range corresponding to a part of the discharge side air seal 12B.

In the first embodiment, the radial cross-section of the through hole 16A of the discharge side shaft portion 5A of the male rotor 1A is circular at a portion A1 in the axial direction, and the discharge side shaft portion 5B of the female rotor 1B is circular. Although the case where the radial cross section of the axial portion B1 of the through hole 16B is circular is described as an example, it is not limited to this, and can be modified within the scope of the gist and technical idea of the present invention. is. For example, as in the modification shown in FIG. 9 or FIG. 10, the radial cross-section of the axial portion A1 or B1 of the through hole of the discharge-side shaft portion has a radial shape (specifically, the center hole and the center hole). A shape consisting of a plurality of grooves extending radially from a hole). In such variations, the plurality of grooves described above may extend linearly in the axial direction, or may extend in a helical shape in the axial direction. Further, for example, as in a modification shown in FIG. 11, the radial cross section of a portion A1 or B1 in the axial direction of the through hole of the discharge-side shaft portion may have a perforated shape. Further, the shape of the radial cross section may be different between the male rotor 1A and the female rotor 1B.

A second embodiment of the present invention will be described with reference to FIGS. 12 and 13. FIG. FIG. 12 is an axial sectional view showing the structure of the male rotor in this embodiment. FIG. 13 is an axial sectional view showing the structure of the female rotor in this embodiment. In addition, in this embodiment, the same code|symbol is attached|subjected to the part equivalent to 1st Embodiment, and description is abbreviate|omitted suitably.

In the present embodiment, a portion C1 of the through hole 14A of the tooth portion 3A of the male rotor 1A in the axial direction (more specifically, the axial length of the tooth portion 3A from the discharge-side end face of the tooth portion 3A to 3/4 or less of the axial length of the tooth portion 3A). ) is larger than the diameter of the remaining portion C2 in the axial direction. Therefore, the circumferential length of the radial cross section of the axial portion C1 of the through hole 14A of the tooth portion 3A is larger than the circumferential length of the radial cross section of the remaining axial portion C2. As a result, the cooling power of the coolant in the relatively high temperature portion C1 can be enhanced, while the cooling power of the coolant in the relatively low temperature portion C2 can be suppressed. Therefore, the cooling efficiency can be improved by the axial distribution of the cooling power of the coolant. Also, the difference between the amount of thermal expansion of the tooth portion 3A on the discharge side and the amount of thermal expansion on the suction side can be reduced, and the gap between the tooth portion 3A and the inner wall of the casing 2 can be reduced. Therefore, compression performance can be improved.

Further, in this embodiment, a portion D1 of the through hole 14B of the tooth portion 3B of the female rotor 1B in the axial direction (more specifically, 3/3 of the axial length of the tooth portion 3B from the discharge side end surface of the tooth portion 3B). 4 or less) is larger than the diameter of the remaining portion D2 in the axial direction. Therefore, the peripheral length of the radial cross-section of the through hole 14B of the tooth portion 3B at the axial portion D1 is larger than the peripheral length of the radial cross-section of the remaining axial portion D2. As a result, the cooling power of the coolant in the relatively high temperature portion D1 can be enhanced, while the cooling power of the coolant in the relatively low temperature portion D2 can be suppressed. Therefore, the cooling efficiency can be improved by the axial distribution of the cooling power of the coolant. Further, the difference between the amount of thermal expansion of the tooth portion 3B on the discharge side and the amount of thermal expansion on the suction side can be reduced, and the gap between the tooth portion 3B and the inner wall of the casing 2 can be reduced. Therefore, compression performance can be improved. The reason why the axial portion C1 or D1 is defined as a portion within 3/4 of the axial length of the tooth portion from the discharge side end face of the tooth portion is that air This is because the temperature increases exponentially.

In the second embodiment, the radial cross-section of the axial portion C1 of the through hole 14A of the tooth portion 3A of the male rotor 1A is circular, and the through hole 14B of the tooth portion 3B of the female rotor 1B is circular. Although the case where the radial cross-section at a portion D1 in the axial direction is circular has been described as an example, it is not limited to this, and modifications are possible without departing from the gist and technical idea of the present invention. For example, a radial cross-section of a portion C1 or D1 in the axial direction of the through-hole of the tooth portion has a radial shape (more specifically, a shape consisting of a central hole and a plurality of grooves radially extending from the central hole). may be In such variations, the plurality of grooves described above may extend linearly in the axial direction, or may extend in a helical shape in the axial direction. Further, for example, the radial cross section of the axial portion C1 or D1 of the through hole of the tooth portion may be porous. Further, the shape of the radial cross section may be different between the male rotor 1A and the female rotor 1B.

In the above description, an oil-free air compressor has been described as an example of application of the embodiments of the present invention. Further, as an application object of the present invention, an air compressor having two screw rotors, the male rotor 1A and the female rotor 1B, has been described as an example. Alternatively, it may be a single screw type in which one screw rotor and one or more gear-shaped rotors (also called gate rotors) are engaged. Or it may be an air compressor with three or more screw rotors. Moreover, in an air compressor provided with a plurality of screw rotors, all of the plurality of screw rotors may have the features of the present invention, or only some of them may have the features of the present invention.

In addition, the present invention is not limited to air compressors, and can be applied to other various gas compressors such as oxygen, nitrogen, and Freon gas. Furthermore, what is pumped by the screw rotor may be anything other than gas, and the present invention is applicable to fluid machinery that conveys fluid, such as pumps, fans, blowers, and expanders.

In the case of an expander, high-pressure gas flows into the interior from the part corresponding to the discharge side of the compressor, and the expansion force rotates the screw rotor to generate mechanical torque, and the gas is then sucked into the compressor. It is designed to be exhaled from the part corresponding to the side. When the inflowing high-pressure gas has a high temperature, there is also a problem of improving the cooling efficiency of the inflow side of the screw rotor (corresponding to the discharge side of the compressor). Therefore, by applying the rotor configuration that is applied to the compressor to the expander, it is possible to improve the cooling efficiency of the inflow-side shaft of the screw rotor (equivalent to the discharge-side shaft of the compressor), which is subject to high temperatures. is.

The male rotor 1A and the female rotor 1B can also be manufactured by, for example, dividing them axially or radially and fixing the cast divided parts by welding, crimping, bolts, or the like. It is also preferable to use lamination molding or the like using a three-dimensional molding machine. That is, the teeth or the teeth and the shaft are three-dimensionally formed as a continuous integral structure. As a result, the thickness and shape of the tooth portion can be formed more complicatedly and accurately, and the strength can be ensured because the rotor is a continuous integral structure by chemical bonding.

As the layered manufacturing method, a stereolithography method, a powder sintering layered manufacturing method, an inkjet method, a raw material melting layering method, a gypsum powder method, a sheet molding method, a film transfer image lamination method, a metal stereolithography composite processing method, and the like can be applied. Further, the material of the screw rotor may be resin or metal. Furthermore, the stacking direction may be horizontal, vertical or oblique.

The electronic data for lamination molding is generated by processing three-dimensional data generated by CAD or CG software or a three-dimensional scanner into NC data by CAM. Three-dimensional modeling is performed by inputting the data into a three-dimensional modeling machine. NC data may be generated directly from three-dimensional data using CAD/CAM software.

1A Male rotor 1B Female rotor 2 Casing 3A, 3B Teeth 4A, 4B Suction side shaft 5A, 5B Discharge side shaft 6A, 6B Suction side bearing 7A, 7B Discharge-side bearings 12A, 12B Discharge-side air seals 14A, 14B Through-holes of teeth 15A, 15B Through-holes of suction-side shaft 16A, 16B Through-holes of discharge-side shaft

Claims (6)

a screw rotor, a casing housing the screw rotor and forming a compression chamber together with tooth grooves of the screw rotor, a suction-side bearing and a discharge-side bearing rotatably supporting the screw rotor, the compression chamber and the discharge. a discharge side seal disposed between the side bearings and suppressing leakage of compressed gas from the compression chamber;
The screw rotor includes a tooth portion in which the tooth spaces are formed, a suction-side shaft portion extending outward from the suction-side end surface of the tooth portion, and a discharge-side shaft portion extending outward from the discharge-side end surface of the tooth portion. It consists of a shaft and
The tooth portion, the suction-side shaft portion, and the discharge-side shaft portion of the screw rotor each have a through hole extending in the axial direction, and a cooling liquid is configured to flow through the through hole. in the machine
The circumferential length of the radial cross-section of the through-hole in a part of the axial direction, which is the range corresponding to the discharge-side seal of the discharge-side shaft portion and the range from the discharge-side seal to the discharge-side end surface of the tooth portion, is larger than the circumferential length of the radial cross section of the through hole in the remaining portion of the discharge-side shaft portion other than the axial portion,
The peripheral length of the radial cross section of the through hole in a part of the axial direction, which is a range of 3/4 or less of the axial length of the tooth portion from the discharge side end surface of the tooth portion, is the same as the tooth. fluid machine, wherein the circumference of the through hole in the remaining portion other than the portion in the axial direction of the portion is larger than the circumferential length of the radial cross section of the through hole. In the fluid machine according to claim 1,
a radial cross-section of the through-hole in the remaining portion of the discharge-side shaft portion in the axial direction is circular;
A radial cross section of the through hole in a portion of the discharge side shaft portion in the axial direction is circular, and the diameter of the through hole in the remaining portion of the discharge side shaft portion in the axial direction is circular. A fluid machine characterized by a diameter dimension larger than a directional cross section. In the fluid machine according to claim 1,
a radial cross-section of the through-hole in the remaining portion of the discharge-side shaft portion in the axial direction is circular;
A fluid machine according to claim 1, wherein a radial cross-section of the through-hole in a portion of the discharge-side shaft portion in the axial direction has a radial shape. In the fluid machine according to claim 1,
A fluid machine, wherein the tooth portion, the suction-side shaft portion, and the discharge-side shaft portion of the screw rotor are integrally formed. In the fluid machine according to claim 4,
A fluid machine, wherein each portion of the screw rotor is divided and integrally formed by welding, bonding, bolting, or a combination of two or more of these. In the fluid machine according to claim 4,
A fluid machine according to claim 1, wherein said screw rotor comprises an integral structure in which each part is continuous by chemical bonding.

Images