WO2016157449A1

WO2016157449A1 - Gas compressor

Info

Publication number: WO2016157449A1
Application number: PCT/JP2015/060244
Authority: WO
Inventors: 大嗣堀内; 笠原　雅之
Original assignee: 株式会社日立産機システム
Priority date: 2015-03-31
Filing date: 2015-03-31
Publication date: 2016-10-06
Also published as: JPWO2016157449A1; JP6482649B2

Abstract

Provided is a gas compressor that can realize improved performance by reducing pressure loss in a discharge passage. The gas compressor comprises: screw rotors (10A, 10B) that engage with each other; a plurality of bearings (15A, 15B, 16A, 16B) that respectively and rotatably support the screw rotors (10A, 10B); timing gears (17A, 17B) that are for causing the screw rotors (10A, 10B) to rotate without contacting each other; and a casing (12, 13). The casing (12, 13) includes: a housing chamber (18) that houses a tooth part (11A) of the male rotor (10A) and a tooth part (11B) of the female rotor (10B) and forms a plurality of compression chambers (S); intake passages (22A, 22B) that are for introducing a gas into the compression chambers (S); and a discharge passage (19) that is for discharging a compressed gas from the compression chambers (S). The discharge passage (19) is formed such that at least part of a discharge port (20) and part of an outlet port (21) overlap projection planes of the timing gears (17A, 17B) in an axial direction.

Description

Gas compressor

The present invention relates to a gas compressor.

For example, an oil-free screw compressor that is one of gas compressors (specifically, the compressor chamber is operated without oil supply) is capable of rotating two screw rotors that mesh with each other and two screw rotors. A plurality of bearings for supporting each, a plurality of timing gears for rotating the two screw rotors in a non-contact manner, and a casing are provided. The casing accommodates the tooth portions of the two screw rotors and forms a plurality of compression chambers in the tooth gaps, a suction passage for sucking gas into the compression chambers, and a compressed gas from the compression chambers. A discharge channel for discharging.

Here, the discharge flow path shown in FIG. 3 of Patent Document 1 is formed so as to be directed substantially in the rotor axial direction. Thereby, compared with the case where it forms so that it may go to a rotor radial direction, it is possible to suppress the change of the flow direction of compressed gas, and to aim at reduction of the pressure loss of a discharge flow path.

Japanese Patent Application Laid-Open No. 2005-232979

However, the discharge flow path shown in FIG. 3 of Patent Document 1 is formed so as not to interfere with the discharge-side timing gear and the bearing. That is, the discharge flow path is formed so that the discharge port which is the compression chamber side opening and the outlet port which is the outlet side opening do not overlap with the axial projection surfaces of the timing gear and the bearing. Therefore, there has been a limit to reducing the compression loss of the discharge flow path.

The present invention has been made in view of the above matters, and an object of the present invention is to improve the performance by reducing the pressure loss of the discharge flow path.

In order to solve the above problems, the configuration described in the claims is applied. The gas compressor of the present invention includes a plurality of means for solving the above-described problems. To give an example, at least two screw rotors that mesh with each other and each of the at least two screw rotors can rotate. A plurality of bearings for supporting, a plurality of timing gears for rotating the at least two screw rotors in a non-contact manner, and a storage chamber for storing the teeth of the at least two screw rotors and forming a plurality of compression chambers A suction flow path for sucking gas into the compression chamber, and a casing having a discharge flow path for discharging compressed gas from the compression chamber, wherein the discharge flow path is a compression chamber of the discharge flow path At least a part of each of the discharge port that is a side opening and the outlet port that is an outlet side opening of the discharge flow path is the timing It is formed so as to overlap with the projected area in the axial direction of Ya.

According to the present invention, compared with the case where the discharge port and the outlet port do not overlap with the axial projection surface of the timing gear, it is possible to reduce the pressure loss of the discharge flow path and improve the performance.

In addition, problems, configurations, and effects other than the above will be clarified by the following description.

It is a horizontal sectional view showing the structure of the gas compressor in a 1st embodiment of the present invention. FIG. 2 is a vertical sectional view taken along section II-II in FIG. FIG. 3 is a partial enlarged cross-sectional view of a part III in FIG. 2 and shows a structure of a discharge channel in the first embodiment of the present invention. It is a three-dimensional figure showing the structure of the lower half of the compressor main body main casing in the 1st Embodiment of this invention. It is a three-dimensional figure showing the structure of the lower half of the compressor main body main casing in the 1st Embodiment of this invention. It is an axial direction projection figure showing the positional relationship of the discharge port in the 1st Embodiment of this invention, an exit port, a storage chamber, a bearing, and a timing gear. It is a partial expanded sectional view which shows the structure of the discharge flow path in the 1st modification of this invention. It is a partial expanded sectional view which shows the structure of the discharge flow path in the 2nd modification of this invention. It is a partial expanded sectional view which shows the structure of the discharge flow path in the 3rd modification of this invention. It is an axial direction projection figure showing the positional relationship of the discharge port in the 4th modification of this invention, an exit port, a storage chamber, a bearing, and a timing gear. It is a partial expanded sectional view which shows the structure of the discharge flow path in the 2nd Embodiment of this invention. It is a three-dimensional figure showing the structure of the lower half of the compressor main body main casing in the 2nd Embodiment of this invention. It is a three-dimensional figure showing the structure of the lower half of the compressor main body main casing in the 2nd Embodiment of this invention. It is an axial direction projection figure showing the positional relationship of the discharge port in the 2nd Embodiment of this invention, an exit port, a storage chamber, a bearing, and a timing gear. It is a partial expanded sectional view which shows the structure of the discharge flow path in the 5th modification of this invention. It is an axial direction projection figure showing the positional relationship of the discharge port in the 5th modification of this invention, an exit port, a storage chamber, a bearing, and a timing gear. It is a partial expanded sectional view which shows the structure of the discharge flow path in the 6th modification of this invention. It is a partial expanded sectional view which shows the structure of the discharge flow path in the 7th modification of this invention. It is a horizontal sectional view showing the structure of the gas compressor in a 3rd embodiment of the present invention. FIG. 20 is a vertical sectional view taken along section XX-XX in FIG. It is a three-dimensional figure showing the structure of the lower half of the compressor main body main casing in the 3rd Embodiment of this invention. It is a three-dimensional figure showing the structure of the lower half of the compressor main body main casing in the 3rd Embodiment of this invention. It is a horizontal sectional view showing the structure of the gas compressor in a 4th embodiment of the present invention.

A first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a horizontal sectional view showing the structure of the gas compressor in the present embodiment. 2 is a vertical cross-sectional view taken along a section II-II in FIG. 1, and FIG. 3 is a partially enlarged cross-sectional view of a portion III in FIG. 4 and 5 are three-dimensional views showing the structure of the lower half of the compressor main body main casing in the present embodiment. FIG. 6 is an axial projection showing the positional relationship among the discharge port, the outlet port, the storage chamber, the bearing, and the timing gear in the present embodiment.

The gas compressor of the present embodiment includes a compressor body 1 and a motor 2 that drives the compressor body 1, and the compressor body 1 and the motor 2 are integrated. In the present embodiment, the compressor body 1 and the motor 2 are placed horizontally so that the rotation shaft of the compressor body 1 and the rotation shaft of the motor 2 described later extend in the horizontal direction, and the compressor body 1 and The motor 2 is connected in the horizontal direction.

The motor 2 includes a rotating shaft 3, a rotor core 4 attached to the rotating shaft 3, a stator core 5 disposed on the outer peripheral side of the rotor core 4, a motor casing 6 to which the stator core 5 is attached, and an axial direction of the motor casing 6 And a motor bracket 7 connected to one side (the right side in FIGS. 1 and 2). A motor cooling jacket 8 is formed on the outer peripheral side of the stator core 5 in the motor casing 6. The motor 2 is cooled by circulating a coolant (oil in this embodiment) through the motor cooling jacket 8. In the present embodiment, a part of the oil supplied to the motor cooling jacket 8 is supplied to a bearing and a timing gear described later.

Compressor body 1 is an oil-free screw compressor. The compressor body 1 includes a pair of male and

female screw rotors

10A and 10B that are engaged with each other, a compressor main body casing 12 that houses the tooth portions 11A of the male rotor 10A and the tooth portions 11B of the female rotor 10B, and the main body of the compressor. A compressor main body suction side casing 13 connected to one axial side of the casing 12 (right side in FIGS. 1 and 2) is provided. The portion on the other side in the axial direction of motor casing 6 (left side in FIGS. 1 and 2) is a portion corresponding to a gear casing, and stores compressor body suction side casing 13 and the like, and also includes a compressor body main casing. 12 is connected.

The shaft portion 14A (rotating shaft) of the male rotor 10A is provided only on one side in the axial direction (in other words, the suction side) with respect to the tooth portion 11A, and is integrally formed with the rotating shaft 3 of the motor 2. The shaft portion 14A of the male rotor 10A is rotatably supported by a bearing 15A provided on the compressor body suction side casing 13, and the rotating shaft 3 of the motor 2 is rotatable by a bearing 16A provided on the motor bracket 7. It is supported. That is, the shaft portion 14A of the male rotor 10A is indirectly supported by the bearing 16A so as to be rotatable. The bearing 15A supports a radial load, and the bearing 16A supports a radial load and a thrust load. The male rotor 10 A is rotated by driving the motor 2.

The shaft portion 14B (rotating shaft) of the female rotor 10B is provided only on one side in the axial direction (in other words, the suction side) with respect to the tooth portion 11B. The shaft portion 14B of the female rotor 10B is rotatably supported by a bearing 15B provided in the compressor main body suction side casing 13 and a bearing 16B provided in the motor casing 6. The bearing 15B supports a radial load, and the bearing 16B supports a radial load and a thrust load.

Timing shafts

17A and 17B are provided on the shaft portion 14A of the male rotor 10A and the shaft portion 14B of the female rotor 10B, and the rotational force of the male rotor 10A is transmitted to the female rotor 10B by the engagement of the timing gears 17A and 17B. As a result, the male rotor 10A and the female rotor 10B rotate synchronously without contact.

The compressor body main casing 12 accommodates the tooth portion 11A of the male rotor 10A and the tooth portion 11B of the female rotor 10B, and forms a plurality of compression chambers S in the tooth gaps (in detail, a part of Two cylindrical bores), and a discharge passage 19 for discharging compressed gas from the compression chamber S. The discharge port 20, which is the compression chamber side opening of the discharge flow channel 19, is formed only in the rotor axial direction with respect to the compression chamber S. An outlet port 21 that is an outlet side opening of the discharge flow channel 19 is formed on a side surface of the casing 12.

Here, as one of the major features of this embodiment, the discharge flow path 19 is formed to extend linearly in the rotor axial direction. As shown in FIG. 6, a part of each of the discharge port 20 and the outlet port 21 is formed so as to overlap with the axial projection surfaces of the timing gears 17A and 17B or the

bearings

15A and 15B.

The

casings

12 and 13 of the compressor body 1 have

suction passages

22A and 22B for sucking gas into the compression chamber S. The suction port 23 that is the compression chamber side opening of the suction passage 22B is formed only in the rotor axial direction with respect to the compression chamber S. An inlet port 24 that is an inlet side opening of the suction flow path 22 A is formed on the upper surface of the casing 12.

And with the rotation of the male rotor 10A and the female rotor 10B, the compression chamber S moves in the rotor axial direction. At this time, the compression chamber S sucks gas (specifically, for example, air) from the

suction flow paths

22A and 22B via the suction port 23, compresses the gas, and enters the discharge flow path 19 via the discharge port 20. Compressed gas is discharged.

In the compressor main body 12, a compressor main body cooling jacket 25 is formed on the outer peripheral portion (except for the suction flow path 22 A) of the tooth portion 11 A of the male rotor 10 A and the tooth portion 11 B of the female rotor 10 B. Has been. The compressor main body 1 is cooled by circulating a coolant (oil in this embodiment) through the compressor main body cooling jacket 25.

Next, the function and effect of this embodiment will be described.

In the present embodiment, the shaft portion 14A of the male rotor 10A is only on the suction side with respect to the tooth portion 11A, the shaft portion 14B of the female rotor 10B is only on the suction side with respect to the tooth portion 11B, and the shaft portion on the discharge side is eliminated. As a result, it is possible to eliminate bearings and seals that should be provided around the shaft portion on the discharge side. Therefore, the structure on the discharge side of the casing 12 can be simplified, and the degree of freedom in design can be increased. Therefore, the discharge channel 19 is formed so that a part of each of the discharge port 20 and the outlet port 21 overlaps with the timing gears 17A and 17B or the axial projection surfaces of the

bearings

15A and 15B. Therefore, compared with the case where the discharge port 20 and the outlet port 21 do not overlap with the axial projection surfaces of the timing gears 17A and 17B or the

bearings

15A and 15B, the pressure loss of the discharge passage 19 is reduced and the performance is improved. Can do. Moreover, discharge noise can also be reduced.

Also, by reducing the number of bearings, mechanical loss (rotation loss) due to the bearings can be reduced. Further, by eliminating the discharge-side shaft portion, the gap itself generated around the shaft portion is eliminated, so that gas leakage from the discharge-side compression chamber S can be reduced. Therefore, the performance can be improved. Cost can also be reduced.

In the first embodiment, in detail, the discharge path 19 extends in a straight line shape in the rotor axial direction, and each radial cross section from the discharge port 20 to the outlet port 21 (however, the discharge port 20 And the outlet port 21 are formed in the same shape and size, and the radial positions thereof are the same. However, the present invention is not limited to this, and the gist and technology of the present invention Modifications can be made without departing from the concept. That is, it is sufficient that at least a part of each of the discharge port 20 and the outlet port 21 is formed so as to overlap with the axial projection surfaces of the timing gears 17A and 17B or the

bearings

15A and 15B, and various modifications are possible. is there.

Specifically, for example, as in the first modification shown in FIG. 7, the discharge flow path 19 is formed so that the radial cross section gradually increases from the discharge port 20 toward the outlet port 21 as a whole. May be. Alternatively, for example, as in the second modification shown in FIG. 8, the discharge flow path 19 has a partial radial cross section from the discharge port 20 toward the outlet port 21 (in this modification, the lower portion is). You may form so that it may expand gradually. In the first embodiment and the first and second modified examples, when the outlet port 21 is projected in the axial direction, it overlaps with most of 80% or more of the discharge port 20.

Further, for example, as in the third modification shown in FIG. 9, the discharge flow path 19 may be formed to be slightly inclined with respect to the rotor axial direction. Specifically, although the shape and size of each radial cross section (including the discharge port 20 and the outlet port 21) from the discharge port 20 to the outlet port 21 are the same, their radial positions change. May be formed. In this modification, the discharge channel 19 is formed so as to incline radially outward (downward in FIG. 9) from the discharge port 20 toward the outlet port 21. Therefore, the overlapping area between the outlet port 21 and the axial projection surfaces of the timing gears 17A and 17B is smaller than the overlapping area between the discharge port 20 and the axial projection surfaces of the timing gears 17A and 17B. Further, the overlapping area between the outlet port 21 and the axial projection surfaces of the

bearings

15A and 15B is smaller than the overlapping area between the discharge port 20 and the axial projection surfaces of the

bearings

15A and 15B.

Further, for example, as in the fourth modification shown in FIG. 10, the discharge flow path 19 may be formed so that the shapes of the discharge port 20 and the outlet port 21 are different and the shape of the radial cross section gradually changes. Good.

Also in the first to fourth modifications described above, as in the first embodiment, the pressure loss of the discharge flow path 19 can be reduced and the performance can be improved.

A second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the description of the same parts as in the first embodiment will be omitted as appropriate.

FIG. 11 is a partially enlarged sectional view showing the structure of the discharge flow path 19 in the present embodiment, and corresponds to FIG. 3 described above. FIG.12 and FIG.13 is a three-dimensional figure showing the structure of the lower half of the compressor main body main casing 12 in this embodiment. FIG. 14 is an axial projection showing the positional relationship among the discharge port, the outlet port, the storage chamber, the bearing, and the timing gear in the present embodiment.

In this embodiment, an axial discharge port 20A that opens in the axial direction with respect to the compression chamber S and a radial discharge port 20B that opens in the radial direction with respect to the compression chamber S are provided. The discharge flow path 19 includes a discharge pocket 26 formed outside the radial discharge port 20B, and is formed to extend linearly from the axial discharge port 20A and the discharge pocket 26 in the rotor axial direction. And as shown in FIG. 14, each of discharge port 20A and exit port 21 is formed so that it may overlap with the axial direction projection surface of

timing gear

17A, 17B or bearing 15A, 15B.

In the present embodiment configured as described above, similarly to the first embodiment, the discharge port 20A and the outlet port 21 are compared with the case where the timing gears 17A, 17B or the axial projection surfaces of the

bearings

15A, 15B do not overlap. The pressure loss of the discharge channel 19 can be reduced and the performance can be improved.

Note that, in the second embodiment, the discharge flow path 19 is, in detail, each radial cross section from the discharge port 20A to the outlet port 21 (however, the discharge port 19) so as to extend linearly in the rotor axial direction. 20A is included and the outlet port 21 is included), and the shape and size thereof are the same and the radial positions thereof are the same. However, the present invention is not limited thereto, and the present invention is not limited thereto. Modifications are possible without departing from the spirit and technical idea of the present invention. That is, it is sufficient that at least a part of each of the discharge port 20A and the outlet port 21 is formed so as to overlap the axial projection surface of the timing gears 17A and 17B or the

bearings

15A and 15B, and various modifications are possible. is there.

Specifically, as in the fifth modification shown in FIGS. 15 and 16, for example, the discharge flow path 19 gradually increases in overall radial cross section from the discharge port 20A toward the outlet port 21. May be formed. Alternatively, for example, as in the sixth modification shown in FIG. 17, the discharge flow path 19 has a partial radial cross section from the discharge port 20 A toward the outlet port 21 (in this modification, the lower portion is). You may form so that it may expand gradually. In the second embodiment and the fifth and sixth modified examples (and the seventh modified example described later), when the outlet port 21 is projected in the axial direction, most of the discharge port 20A is 80% or more. It is supposed to overlap.

Further, for example, as in the seventh modification shown in FIG. 18, the discharge flow path 19 may be formed to be slightly inclined with respect to the rotor axial direction. In detail, although the shape and size of each radial section from the discharge port 20A to the outlet port 21 (but not including the discharge port 20A and including the outlet port 21) are the same, their radial positions are It may be formed to change. In the present modification, the discharge channel 19 is formed so as to incline radially outward (downward in FIG. 18) from the discharge port 20A toward the outlet port 21. Therefore, the overlapping area between the outlet port 21 and the axial projection surfaces of the timing gears 17A and 17B is smaller than the overlapping area between the discharge port 20A and the axial projection surfaces of the timing gears 17A and 17B. Further, the overlapping area between the outlet port 21 and the axial projection surfaces of the

bearings

15A and 15B is smaller than the overlapping area between the discharge port 20A and the axial projection surfaces of the

bearings

15A and 15B.

Also in the fifth to seventh modified examples described above, as in the second embodiment, the pressure loss of the discharge flow path 19 can be reduced and the performance can be improved.

A third embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the description of the same parts as in the first embodiment will be omitted as appropriate.

FIG. 19 is a horizontal sectional view showing the structure of the gas compressor in the present embodiment. 20 is a vertical sectional view taken along a section XX-XX in FIG. FIG.21 and FIG.22 is a three-dimensional figure showing the structure of the lower half of the compressor main body main casing in this embodiment.

In this embodiment, as described above, the structure on the discharge side of the casing 12 can be simplified, and the degree of freedom in design can be increased, so the cooling jacket 25A is enlarged. That is, the cooling jacket 25A includes not only the outer peripheral portion of the tooth portion 11A of the male rotor 10A and the tooth portion 11B of the female rotor 10B (however, the portion excluding the suction flow path 22A), as well as the tooth portion 11A of the male rotor 10A. The upper end surface and the upper end surface of the tooth portion 11B of the female rotor 10B are also formed in a portion (however, a portion excluding the discharge passage 19).

Thereby, the discharge side portion can be efficiently cooled, and the discharge side gap caused by thermal expansion can be reduced. Therefore, the gas leakage from the compression chamber S on the discharge side can be suppressed and the performance can be improved.

A fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the description of the same parts as in the first embodiment will be omitted as appropriate.

FIG. 23 is a horizontal sectional view showing the structure of the gas compressor in the present embodiment.

The gas compressor of the present embodiment includes a flat motor 2A having a shaft dimension smaller than the diameter dimension. The motor 2A is, for example, an axial gap type, and includes two rotor cores 4A attached to the rotation shaft 3A and a stator core 5A disposed between the two rotor cores 4A. By adopting this flat motor 2A, it is possible to reduce the axial dimension of the entire compressor. Alternatively, as the axial dimension of the motor becomes smaller, the distance between the

bearings

15B and 16B that support the female rotor 10B can be increased, and thereby the swing of the female rotor 10B may be suppressed.

In the third and fourth embodiments, the case where the structure of the discharge channel 19 of the first embodiment is adopted is illustrated as an example, but the present invention is not limited to this, and the second embodiment and the first to first embodiments are illustrated. You may employ | adopt the structure of the discharge flow path in either of the 7th modification.

In the first to fourth embodiments, the case where the compressor body 1 is an oil-free type and the male rotor 10A and the female rotor 10B are rotated in a non-contact manner by the timing gears 17A and 17B has been described as an example. Not limited to this. That is, for example, the compressor body 1 is an oil supply type or a water supply type (specifically, the compressor chamber S is operated in an oil supply state or a water supply state), and the male rotor 10A and the female rotor are not provided without the timing gears 17A and 17B. 10B may be contacted and rotated. In this case as well, the discharge channel 19 is formed so that at least a part of each of the discharge port 20 (or 20A) and the outlet port 21 overlaps the axial projection surface of the

bearings

15A and 15B. An effect can be obtained.

In the first to fourth embodiments, the case where the shaft portion 14A of the male rotor 10A is integrally formed with the rotating shaft 3 of the motor 2 has been described as an example. However, the present invention is not limited to this. That is, although the shaft portion 14A of the male rotor 10A and the rotating shaft 3 of the motor 2 are molded separately, they may be connected coaxially. Further, instead of the shaft portion 14A of the male rotor 10A, the shaft portion 14B of the female rotor 10B may be integrally formed with the rotating shaft 3 of the motor 2 or connected coaxially.

In the first to fourth embodiments, the compressor body 1 and the shaft portion 14A of the male rotor 10A, the shaft portion 14B of the female rotor 10B, and the rotating shaft 3 of the motor 2 extend in the horizontal direction. The case where the motor 2 is placed horizontally has been described as an example, but is not limited thereto. That is, the compressor body 1 and the motor 2 are placed vertically so that the shaft portion 14A of the male rotor 10A, the shaft portion 14B of the female rotor 10B, and the rotating shaft 3 of the motor 2 extend in the vertical direction, and the compressor The main body 1 may be disposed on the upper side of the motor 2. In this case, the same effect as described above can be obtained.

In the above description, the case where the two

screw rotors

10A and 10B mesh with each other has been described as an example. However, the present invention is not limited to this, and it is needless to say that three or more screw rotors meshing with each other may be included.

DESCRIPTION OF

SYMBOLS

2,2A ... Motor, 10A, 10B ... Screw rotor, 11A, 11B ... Tooth part, 12 ... Compressor body main casing, 13 ... Compressor body suction side casing, 14A, 14B ... Shaft part, 15A, 15B, 16A, 16B ... Bearing, 17A, 17B ... Timing gear, 18 ... Storage chamber, 19 ... Discharge flow path, 20 ... Discharge port, 20A ... Axial discharge port, 20B ... Radial discharge port, 21 ... Outlet port, 22A, 22B ... Suction flow Road, 25, 25A ... Cooling jacket

Claims

At least two screw rotors meshing with each other;
A plurality of bearings respectively rotatably supporting the at least two screw rotors;
A plurality of timing gears respectively provided on the at least two screw rotors for rotating the at least two screw rotors without contact with each other;
A storage chamber for storing the teeth of the at least two screw rotors and forming a plurality of compression chambers, a suction passage for sucking gas into the compression chamber, and a discharge for discharging compressed gas from the compression chamber A casing having a flow path,
In the discharge flow path, at least a part of the discharge port that is the compression chamber side opening of the discharge flow path and the outlet port that is the outlet side opening of the discharge flow path overlaps the axial projection surface of the timing gear. A gas compressor characterized by being formed as described above.
At least two screw rotors meshing with each other;
A plurality of bearings respectively rotatably supporting the at least two screw rotors;
A storage chamber for storing the teeth of the at least two screw rotors and forming a plurality of compression chambers, a suction passage for sucking gas into the compression chamber, and a discharge for discharging compressed gas from the compression chamber A casing having a flow path,
In the discharge flow path, at least a part of each of the discharge port which is the compression chamber side opening of the discharge flow path and the outlet port which is the outlet side opening of the discharge flow path overlaps the axial projection surface of the bearing. A gas compressor formed as described above.
The gas compressor according to claim 1, wherein
The gas compressor, wherein the discharge flow path is formed so that the shape and size of each radial cross section from the discharge port to the outlet port are the same.
The gas compressor according to claim 1, wherein
The gas compressor, wherein the discharge flow path is formed so that a radial cross section gradually increases from the discharge port toward the outlet port.
The gas compressor according to claim 1, wherein
The gas compressor according to claim 1, wherein the discharge passage is formed so as to overlap most of 80% or more of the discharge port when the outlet port is projected in the axial direction.
The gas compressor according to claim 1, wherein
The discharge flow path is formed so that an overlapping area between the outlet port and the axial projection surface of the timing gear is smaller than an overlapping area between the discharge port and the axial projection surface of the timing gear. Characteristic gas compressor.
The gas compressor according to claim 2, wherein
The discharge flow path is formed such that an overlapping area between the outlet port and the axial projection surface of the bearing is smaller than an overlapping area between the discharge port and the axial projection surface of the bearing. Gas compressor.
The gas compressor according to claim 1, wherein
The gas compressor according to claim 1, wherein the shaft portion of the at least two screw rotors is provided only on the suction side which is one side in the axial direction with respect to the tooth portion.
The gas compressor according to claim 8, wherein
The said casing has a cooling jacket formed at least in the part which the discharge side end surface of the said tooth | gear part opposes, The air compressor characterized by the above-mentioned.
The gas compressor according to claim 8, wherein the motor is a flat type in which an axial dimension of the motor is smaller than a diameter dimension of the motor.