JPS5848757B2 - screw fluid machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a screw fluid machine used as a compressor for generating high-pressure gas, a compressor for a refrigerator, a compressor for an air conditioner, or the like.

An example of a conventional screw fluid machine will be explained with reference to FIGS. 1 and 2.

The screw fluid machine shown in the figure is composed of a drive motor 1, a transmission 2, and a compressor 3, and the drive motor 1 and transmission 2 are installed on a common foundation 5.

The compressor 3 includes a low-pressure stage compressor 3l and a high-pressure stage compressor 3h, and is fixed to the casing 6 of the transmission 2 by seven lunges.

The cooler 4 consists of an intercooler 41 and a post-cooler 4a, and the intercooler 41 includes a low pressure stage compressor 3l and a high pressure stage compressor 3.
The post-cooler 4a is inserted in the gas flow path between the
It is inserted into the discharge gas flow path of the high pressure stage compressor 3h.

The transmission 2 has a rotating shaft 9 supported by a casing 6 via bearings 7 and 8 .

A drive gear 10 is fixed to this rotating shaft 9.

Two driven gears 11 and 12 mesh with the drive gear 10, and the driven gear 11 is connected to the rotor shaft 13 of the low-pressure compressor 31.
The driven gears 12 are each fixed to a rotor shaft 14 of the high-pressure compressor 3h.

One end of the rotating shaft 9 penetrates the casing 6 and projects to the outside. A coupling 15 is attached to this projecting end, and the rotating shaft 9 and the drive motor 1 are connected by the coupling 15.

A suction side silencer 16 is installed in the suction gas flow path of the low pressure stage compressor 3L.
is installed, and a discharge side muffler 17 is installed in the discharge gas flow path of the high-pressure stage compressor 3h.

In such a conventional screw fluid machine, the low-pressure stage compressor 31, the high-pressure stage compressor 3h, and the transmission 2 are considered to be integrated, but these and the intercooler 4
i. The postcooler 4a, the suction side muffler 16, the discharge side muffler 17, or although not shown in this embodiment, the auxiliary equipment of the compressor 3 such as an oil separator and an oil cooler are integrated. Moreover, the above-mentioned auxiliary devices are combined appropriately according to the required specifications, which results in a poor space factor and requires a large installation space.

In addition, since the compressor 3, which is the source of noise, is exposed, the sound is directly transmitted to the surroundings and the noise is loud.

An object of the present invention is to provide a screw fluid machine that is low in noise and has a compact structure including auxiliary equipment.

A feature of this invention is that the discharge passage connected to the working space via the discharge port is located inside the inner wall of the main casing, and the auxiliary equipment is housed in the space between the inner wall of the main casing and the inner wall of the main casing.

In this way, when the discharge passage is installed inside the inner wall, the sound generated in the working space during operation is transmitted to the discharge passage through the discharge port, and when it reaches the outside from the discharge passage, it is attenuated by the inner wall, outer wall, and auxiliary equipment. As a result, the noise felt outside can be kept extremely low.

An embodiment of the present invention will be described below with reference to the drawings.

3 to 6 show a first embodiment of the present invention.

The casing consists of a main casing 18, a suction side end face casing 19, and a discharge side end face casing 20, which are connected to each other by bolts and are integrated.

In the main casing 18, an inner wall 22 is arranged inside an outer wall 21 at a certain distance away from the outer wall 21, and both walls 2L22 are connected between the outer wall 21 and the inner wall 22, and the outer wall 21 and the inner wall 22 are connected to each other. A plurality of ribs 23 (23a to 23g) are provided to divide the space between them into a plurality of small spaces.

Inside the inner wall 22, two working spaces each consisting of two intersecting cylindrical holes are installed, and one working space 24 is for a low pressure stage and is formed by a wall 25, a part of which also serves as the inner wall 22. The other working space 26 is for a high pressure stage and is formed by a wall 27, a part of which also serves as the inner wall 22.

A low pressure stage discharge passage 28 is connected to the low pressure stage working space 24 through a low pressure stage discharge port 28a, and a high pressure stage discharge passage 29 is connected to the high pressure stage working space 26 through a high pressure stage discharge port 29a.

Both discharge passages 28 and 29 are installed inside the inner wall 22.

Among the plurality of small spaces between the outer wall 21 and the inner wall 22, each small space 30, 31, 32, 33 has a heat transfer tube group 30t,
31t, 32t, 33t are arranged, and a small space 30
．． 31 is used as an intercooler IC that cools the compressed gas flowing from the low pressure stage to the high pressure stage, and small spaces 32 and 33 are used as postcoolers AC that cool the compressed gas discharged from the high pressure stage.
used as.

The small space 34 is used as a return passage for guiding the compressed gas discharged from the small space 31 of the intercooler IC to the suction passage of the high-pressure stage working space 26.

Further, the space 35 is used as a passageway for guiding the compressed gas discharged from the small space 33 of the post-cooler AC to the exhaust port.

These two passages 34 and 35 are not necessarily necessary passages, but are based on the relationship between the outlet of the small space 31 of the intercooler IC and the inlet of the low-pressure stage suction passage, and the outlet of the small space 33 of the postcooler AC. It may not be necessary depending on the positional relationship between the outlet and the outlet.

Gap adjustment holes 36 and 37 pass through the outer wall 21 and the inner wall 22 to form a low pressure stage working space 24 and a high pressure stage working space 2.
6 are arranged in series.

When fitting a timing gear to a male rotor shaft and a female rotor shaft to be described later, these gap adjustment holes 36 and 37 are designed so that the gap between the male and female rotors is the same on both the forward and backward surfaces of the rotor tooth profile. Blind flange 3 is a working hole used when performing work that is normally unnecessary.
It is blocked by 8,39.

The low pressure stage working space 24 houses a male rotor 401 and a female rotor 411 that mesh with each other.

Bearings 421 are installed on the shafts of both rotors 40l and 411.
, 431 are arranged, and the discharge side of the rotor is supported by the main casing 18 via a bearing 421, and the suction side is supported by the suction side end face casing 19 via a bearing 431.

At the shaft part of the male rotor 401 and female rotor 411,
A pair of timing gears 44l and 451 are fitted.

Since the rotor, bearing, and timing gear are the same for the high-pressure stage, they will be indicated by adding an h after the number, and the explanation will be omitted.

Further, a driving gear 461 for transmitting rotor driving force is fitted into the shaft portion of the male rotor 401.

Although not shown, there is a drive gear for the high pressure stage as well.

The suction side casing end face 19 has a low pressure stage suction passage 47l.
, a communication passage 48 that communicates the insides of the tube group 30t and the tube group 31t of the intercooler IC, a high-pressure stage suction passage 47h,
A communication passage 49 is provided that communicates the inside of the tube group 32t and the tube group 33t of the post-cooler AC, and these passages are partitioned by an outer wall 50 and a partition wall 51.

The discharge end face casing 20 includes a communication passage 52 that communicates the low-pressure stage discharge passage 28 with the inside of the tube group 30t of the intercooler IC, and a communication passage 52 that communicates the inside of the tube group 31t of the intercooler IC with the return passage 34. A communication passage 53 communicates the high-pressure stage discharge passage 29 with the inside of the heat exchanger tube group 32t of the post-cooler AC, and a communication passage 54 communicates the inside of the heat exchanger tube group 33t of the post-cooler AC with the return passage 35. A communication passage 55 is provided, and each of these passages is partitioned by an outer wall 56 and a partition wall 57.

Next, the operation of this embodiment will be explained.

A dog gear 58, a driving gear 461 . 46h, the male rotors 401 and 40h are driven.
0h rotation by timing gears 441, 44h, 45L4
5h to the female rotors 411, 41h, and the male rotor 401, the female rotor 411, and the male rotor 40
h and the female rotor 41h are meshed and rotated.

As the rotors 401 and 411 rotate, the suction passage 4
Air or other gas (hereinafter simply referred to as gas) is sucked into the working space 24 from the rotors 401 , 41 .
1 to an intermediate pressure and then discharged into the discharge passage 28 through the discharge port 28a.

The discharged intermediate pressure compressed gas passes through a path between the communication passage 52 - the heat exchanger tube group 30t of the intercooler IC - the communication passage 48 - the heat exchanger tube group 31t of the intercooler IC, and then reaches the heat exchanger tube group 3.
When passing through the interior of 0t and 31t, it is cooled by the cooling liquid flowing outside.

After being cooled, the intermediate pressure compressed gas passes through the path of communication passage 53 - return passage 34 - suction passage 47h and is sucked into working space 26 .

Within this working space 26, the fluid is further compressed to a desired pressure by the rotors 40h and 41h and then discharged into the discharge passage 29 via the discharge port 29a.

The discharged compressed gas at the desired pressure passes through the communication passage 54 = inside the heat exchanger tube group 32t of the post-cooler AC = the communication passage 50 - the path inside the heat exchanger tube group 33t of the post-cooler AC, and then the heat exchanger tube group 32
t, 33t, it is cooled by the cooling liquid flowing outside.

After being cooled, the compressed gas at the desired pressure is sent via the return passage 35 to the discharge passage 58 to the point of use.

In the above embodiment, intercooler IC and postcooler A
The heat exchanger tube group 31 t has been described above.
, 33t are removed and the inner walls of the small spaces 31 and 33 are lined with sound absorbing material instead, it is possible to provide a discharge side muffler in addition to the intermediate and post-coolers.

In addition, by changing the positions of the partition walls 51 and 57 of the suction side end face casing L1 and the discharge side end face casing 20, or by changing the arrangement of each small space of the main casing 18 in addition to this change, it is possible to It may be equipped with a silencer on the suction side.

FIG. 7 shows another embodiment of the invention, and is a cross-sectional view of the main casing.

Inside the outer wall 21, a working space 60 is defined by a partition wall 59.
, a discharge passage 61, spaces 62 and 63 for post-cooler AC, and a discharge passage 64 are formed.

The discharge passage 61 is located in the center of the outer wall 21.

The rotor, timing gear, drive gear, etc. housed in the working space 60 are the same as in the previous embodiment.

Further, heat transfer tube groups 62t and 63t are arranged inside the heat exchanger spaces 62 and 630 of the post-cooler AC.

Although not shown in the figure, the suction side casing is provided with a communication passage that communicates the suction passage and the inside of the tube group 62t and the tube group 63t of the post-cooler AC, and the discharge side casing k is provided with a communication passage that communicates with each other the inside of the tube group 62t and the tube group 63t of the post-cooler AC. 61 and the inside of the tube group 62t of the post-cooler AC, and a communication path that connects the inside of the tube group 63t of the post-cooler AC with the discharge passage 64 are provided.

Since the operation of this embodiment is substantially the same as the explanation up to the intercooler IC of the previous embodiment (or the explanation after gas is sucked into the high-pressure stage working space 26), the explanation of the operation will be given here. Omitted.

In FIG. 7, the gap measuring hole and the blind flange that closes this hole are designated by the same reference numerals 36 and 38 as in the previous embodiment.

FIGS. 8 and 9 show another embodiment of the present invention, which is an example applied to an oil injection type screw fluid machine.

The casing consists of a main casing 18, a suction side end casing 11, and a discharge side end casing 11, which are joined together by bolts or the like.

Inside the outer wall 21 of the main casing 19 are a working space 60 consisting of two cylindrical holes that intersect with each other, two spaces 65 and 66 for oil coolers, an oil tank 67, and an oil separator 68.
, discharge passage 61, oil jacket 69, and suction passage 7
5 are provided, and each of these spaces is partitioned by a partition wall.

In the working space 60, there are male rotors 7 that mesh with each other and rotate.
0, a female rotor 71 is housed.

The shaft portions of both rotors 70 and 710 are supported by the main casing 18 via a bearing 72 and by the suction side casing 1 via a bearing 73.

The oil jacket 69 and the working space 60 are communicated through an oil injection port 74.

Groups of tubes 65t, 66t are arranged in spaces 65, 66 for oil coolers.

A filter element 68f is arranged in the oil separator 68.

The suction side end face casing 19 is provided with a suction passage 75, a communication passage 76 that communicates the oil jacket 69 with the inside of the tube groups 65t and 66t of the oil cooler, and a discharge pipe 77.

Although it is not shown in the figure, on the second side of the discharge side end casing,
Oil is supplied from the gear pump (not shown) to the oil cooler tube bank 65.
A passage is provided leading into the t t 66t.

Next, the operation of this embodiment will be explained.

The male rotor 70 is driven by a driver (not shown), and the female rotor 71 meshed with the male rotor 70 is directly driven by the male rotor 70.

Meanwhile, a gear pump (not shown) is also driven at the same time.

(Gear pumps are often attached to the shaft end of the rotor, so there is often no need to specifically drive the gear pump.) Due to the meshing rotation of the male and female rotors 70 and 71, air (or Other gases) are sucked in, compressed to a desired pressure, and then discharged into the discharge passage 61 through the discharge port 61a.

On the other hand, the oil sucked from the oil tank 67 by the gear pump is pumped into the tube groups 65t and 66t of the oil cooler.
While passing through tube group 66t, it is cooled by the cooling liquid outside tube groups 65t and 66t.

After cooling, this oil is pumped to the oil jacket 69 via the communication passage 76.

From here, the oil is injected through the injection port 74 to the position of the compression process in the working space 60 to cool the compressed gas, lubricate it, and create airtightness between the rotors and between the rotor and the casing. is discharged.

This oil and the compressed gas enter the oil tank 67 from the discharge passage 61, where relatively large droplets of oil are removed.

The compressed gas containing small oil droplets enters the oil separator 68, most of the oil droplets in the compressed gas are removed by the filter element 68f, and is sent from the discharge pipe 77 to the point of use.

Although this embodiment has been described with reference to an oil cooler, part of the oil cooler can also be used as a compressed gas cooler.

In each of the above-described embodiments, a cooler is described in which compressed gas flows inside the heat exchanger tube and coolant flows outside the heat exchanger tube, but the reverse may be used.

Furthermore, when obtaining high-pressure gas, the required state of the gas differs depending on its use, and the same auxiliary equipment as in the above-mentioned embodiments is not necessarily provided.

Therefore, even if a necessary auxiliary device is selected depending on the application, and the type of the selected auxiliary device is different from that shown in the embodiments, it is still within the scope of the present invention.

As described above in detail, the present invention uses a common casing that houses the compressor and auxiliary equipment such as a muffler, cooler, oil separator, and oil tank, and also forms a gas flow path within the casing. Therefore, the number of parts constituting the fluid machine can be reduced by about 20 to 30% compared to conventional ones, and the number of processing steps, assembly steps, etc. can be reduced by 30 to 40%.

At the same time, miniaturization can also be achieved.

Furthermore, this invention arranges auxiliary equipment such as a cooler, a silencer, an oil separator, and an oil tank so as to cover the working space of the compressor, and also includes a conventional joint part in the gas passage. Since there is almost no sound and the discharge passage is located inside the inner wall or in the center of the casing, the sound propagating to the outside can be extremely low.

It has been experimentally confirmed that the noise level of a screw compressor is highest in the discharge passage, so the noise damping effect of placing the discharge passage inside the inner wall or in the center of the casing is extremely significant, and compared to conventional This is more than 10dB lower than that of screw fluid machines.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams of a conventional screw fluid machine, FIGS. 3 to 9 are explanatory diagrams of the present invention, and FIG. 3 is a longitudinal sectional view of a main casing of one embodiment. , 4th
The figure is a cross-sectional view taken along the line IV-IV in Figure 3, Figure 5 is a cross-sectional view taken along the ■-V line in Figure 3, Figure 6 is a cross-sectional view taken along the line Vl-vi in Figure 3, and Figure 7 is a cross-sectional view taken along the line Vl-vi in Figure 3. Example main casing cross-section,
FIG. 8 is a cross-sectional view of the main casing of still another embodiment, and FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. 8. 18... Main casing, 19...
Suction side end casing, 20...Discharge side end casing, 21...Outer wall, 22...Inner wall, 23...Riff, 24, 26, 60. ...
...Working space, 2B, 29, 61...Discharge passage, 30,3L62,63...Intercooler space, 32,33...Post-cooler space space, 34,3
5...Return passage, 401, 40h, 70...
...Male rotor, 41 l, 41h, 71...
...Female rotor, 421, 42h, 431, 43
h, 72, 73...Bearing, 44l, 44h,
4sl, 45h... timing gear, 461,
46h... Drive gear, 471, 47h...
... Suction passage, 53, 54, 55... Communication passage, 64... Discharge passage, 65, 66...
・Space for oil cooler, 67...Oil tank, 68
... Oil separator, 69 ... Oil jacket, 74 ... Oil injection port.

Claims (1)

[Claims] 1. A main casing having a working space, an end face casing coupled to an end face of the main casing, and a screw rotor rotatably housed in the working space, in which gas passes through an inlet. The main casing includes an outer wall, an inner wall formed inside the outer wall at a distance from the outer wall, and the inner wall. and an outer wall, and a rib that partitions a space formed between the inner wall and the outer wall into a plurality of small spaces, and a discharge passage connected to the working space via a discharge port is located inside the inner wall. , the end casing has a passage connecting two or more of the small spaces with each other when the main casing is connected to the main casing, and the small space of the main casing has a passage selected from auxiliary equipment for screw fluid machines. done1
A screw fluid machine characterized by containing the above auxiliary equipment.