JP5864286B2 - Oil-free screw compressor - Google Patents

Description

  The present invention relates to an air-cooled and oil-free screw compressor.

  As a screw compressor used in a factory or the like as an air source, Patent Document 1 discloses an oil supply type air compressor. In this air compressor, an air flow is created by a cooling fan provided in the package, and the motor, gas cooler, and oil cooler are cooled in this order by the cooling air taken in from the opening of the package, and the cooled air is Exhausting from the exhaust port. However, in this configuration, the air that has cooled the motor and gas cooler rises in temperature, and not only can the oil cooler be sufficiently cooled, but the air flow is limited to the right half where the motor etc. is located, and the equipment on the left side Can not be cooled.

  Further, in Patent Document 2, a package is divided into two chambers, and an air flow is created by fans provided in the respective chambers. The gas cooler and the oil cooler are cooled in one chamber, and the motor is cooled in the other chamber. A screw compressor of the type is disclosed. However, in this configuration, the fan is too far away from the motor, and the motor cannot be cooled sufficiently, and the opening for taking in cooling air for cooling the gas cooler and the oil cooler needs to be enlarged, and noise from the opening increases. .

JP 2009-138648 A Japanese Utility Model Publication No. 5-7989

  By the way, in an oil-free (oil-free) screw compressor that does not use oil in the compression section, the compressed air is likely to become hot. Therefore, more cooling air is supplied to the gas cooler that cools the compressed air than the oil-fed screw compressor There is a need.

  To capture more cooling air, use a larger fan or increase the fan speed to improve the cooling performance of the fan, increase the intake and exhaust openings, and from the openings to the heat source It is necessary to secure a cooling air path. However, increasing the cooling performance of the fan increases the noise. Further, if the opening for intake and exhaust is enlarged, noise in the package is likely to leak to the outside. Further, if a cooling air path from the opening to the heat source is secured, the path becomes a noise propagation path, and noise is likely to leak from the opening.

  An object of the present invention is to provide an oil-free screw compressor capable of sufficiently cooling a heat source while reducing noise leaking to the outside.

The oil-free screw compressor according to the present invention is an oil that cools air compressed by a compressor body driven by a motor with a gas cooler and cools lubricating oil used in the drive system of the compressor body with an oil cooler. A free screw compressor, a package containing the motor, the compressor body, the gas cooler and the oil cooler, an internal device provided in the package, and an intake opening provided in the package An exhaust opening provided in the package; and cooling air is taken into the package from the intake opening, and the air in the package is discharged from the exhaust opening to the outside. a fan for discharging, has a motor fan for cooling the motor, the intake opening, the first opening, the Opening and consists of at least three openings of the third opening, the cooling air taken into the package from the first opening, through the oil cooler, the fan, the gas cooler in this order The cooling air discharged to the outside from the exhaust opening and taken into the package from the second opening passes through the motor fan, the motor, the fan, and the gas cooler in this order, and is used for the exhaust. Cooling air discharged to the outside through the opening and taken into the package from the third opening passes through the internal device, the fan, and the gas cooler in this order, and is discharged to the outside from the exhaust opening. It is characterized by that.

According to said structure, the cooling air taken in in the package from the 1st opening part mainly cools an oil cooler, and is discharged | emitted outside from the opening part for exhaust. Further, the cooling air taken into the package from the second opening mainly cools the motor and is discharged to the outside through the exhaust opening. In addition, the cooling air taken into the package from the third opening mainly cools the internal device and is discharged to the outside through the exhaust opening. As described above, the package mainly includes a first opening for cooling the oil cooler, a second opening for mainly cooling the motor, and a third opening for mainly cooling the internal equipment. Therefore, each of the oil cooler, the motor, and the internal device, which are heat sources, can be suitably cooled. Then, first opening the intake opening, the second opening, and at least three such from the opening Runode of the third opening, while securing a sufficient open area for the entire air intake opening The noise emitted from each opening can be dispersed and reduced. Thereby, the heat source can be sufficiently cooled while reducing noise leaking to the outside.

Further, in the oil-free screw compressor of the present invention, the intake opening, the first opening, the second opening, the third opening, and, from the four openings of the fourth opening Thus , the cooling air taken into the package from the fourth opening may pass through the fan and the gas cooler in this order and be discharged to the outside from the exhaust opening. According to said structure, the cooling air taken in in the package from the 4th opening part mainly cools a gas cooler, and is discharged | emitted outside from the opening part for exhaust_gas | exhaustion. Thus, since the package is provided with the fourth opening mainly for cooling the gas cooler, the gas cooler as the heat source can be suitably cooled. Then, first opening the intake opening, the second opening, third opening, and, Runode such four openings of the fourth opening, the opening area of the entire air intake opening sufficiently In addition, the noise emitted from each opening can be dispersed and reduced.

Further, in the oil-free screw compressor of the present invention, the sum of the opening area of the opening area and the third opening of the second opening, a 1/3 or less of the opening area of the entire air intake opening It's okay. According to said structure, since the cooling air taken in in a package from a 2nd opening part is drawn in in a package by a motor fan, it exists in the tendency for air volume to increase. Therefore, the sum of the opening area of the second opening and the opening area of the third opening is made smaller than 1/3 of the opening area of the entire intake opening, and the opening area of the first opening is relatively small. Alternatively, the sum of the opening area of the first opening and the opening area of the fourth opening is set to 2/3 or more of the opening area of the entire intake opening, and is taken into the package from each opening. By adjusting the air volume of the cooling air, each heat source can be suitably cooled.

In the oil-free screw compressor according to the present invention, the first opening may be provided in the vicinity of the oil cooler. According to said structure, an oil cooler can be suitably cooled with the cooling air taken in in the package from the 1st opening part by providing a 1st opening part in the vicinity of an oil cooler.

In the oil-free screw compressor according to the present invention, the third opening may be provided on the downstream side of the motor fan and on the upstream side of the internal device. According to the arrangement, a third opening a downstream side of the motor fan, by providing the upstream side of the internal device, the exhaust air of the cooling air taken into the package from the third opening by the motor fan It can be made to flow toward the internal device by force. Thereby, an internal apparatus can be suitably cooled with the cooling air taken in in the package from the 3rd opening part.

  In the oil-free screw compressor according to the present invention, the exhaust opening may be provided in the vicinity of the gas cooler. According to said structure, by providing the opening part for exhaust in the vicinity of a gas cooler, a gas cooler can be suitably cooled with the air discharged | emitted from the opening part for exhaust.

  In the oil-free screw compressor according to the present invention, the motor fan may be built in the motor. According to said structure, while using the motor fan incorporated in the motor, while reducing cost, a package can be reduced in size.

Further, in the oil-free screw compressor according to the present invention, the cooling air provided between the first opening and the compressor body passes through the cooling air taken in from the first opening, and from the compressor body. it may further have a first opening portion side duct for blocking the propagation of sound towards the first opening. According to said structure, propagation of the sound which goes to a 1st opening part from a compressor main body is interrupted | blocked by the 1st opening part side duct provided between the 1st opening part and the compressor main body. Thereby, since the noise from a compressor main body does not leak directly from a 1st opening part, the noise which leaks outside can be reduced.

In the oil-free screw compressor of the present invention, the second opening disposed between the motor, the with cooling air taken in from the second opening passes through said from the motor second opening You may further have the 2nd opening part side duct which interrupts | blocks the propagation of the sound which goes to a part. According to said structure, propagation of the sound which goes to a 2nd opening part from a motor is interrupted | blocked by the 2nd opening part side duct provided between the 2nd opening part and the motor. Thereby, since the noise from a motor does not leak directly from a 2nd opening part, the noise which leaks outside can be reduced.

Further, in the oil-free screw compressor according to the present invention, the cooling air provided between the third opening and the compressor body passes through the cooling air taken in from the third opening, and from the compressor body. it may further have a third opening side duct for blocking the propagation of sound toward the third opening. According to said structure, propagation of the sound which goes to a 3rd opening part from a compressor main body is interrupted | blocked by the 3rd opening part side duct provided between the 3rd opening part and the compressor main body. Thereby, since the noise from a compressor main body does not leak directly from the 3rd opening part, the noise which leaks outside can be reduced. Further, the end of the third opening side duct opposite to the third opening is positioned at the downstream side of the motor fan and at a position where the influence of the fan flow is small (for example, between the motor and the bottom surface of the package). The cooling air taken in from the third opening can be easily flown to the internal device side.

According to the oil-free screw compressor of the present invention, as the opening for mainly cooling the one of at least three heat sources are provided for each heat source, opening intake is such at least three openings Runode, Each of the heat sources can be suitably cooled, and noise emitted from each opening can be dispersed and reduced while sufficiently securing an opening area as a whole intake opening. Thereby, the heat source can be sufficiently cooled while reducing noise leaking to the outside.

It is a perspective view which shows an oil-free screw compressor. It is a perspective view which shows an oil-free screw compressor. It is a perspective view which shows an oil-free screw compressor. It is a perspective view which shows a fan.

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

(Configuration of oil-free screw compressor)
The oil-free screw compressor 1 according to the present embodiment cools air compressed by a compressor body 4 driven by a motor 3 with a gas cooler 5 and oils lubricating oil used in a drive system of the compressor body 4. It cools with the cooler 6, Comprising: As shown in FIG. 1, it has the hexahedral package 2 which incorporates the motor 3, the compressor main body 4, the gas cooler 5, and the oil cooler 6. As shown in FIG. In FIG. 1B, the upper surface 2a, the right side surface 2e, the back surface 2d, and the oil cooler 6 of the package 2, an intake duct 11 to be described later, an intake port communicating with the intake duct 11, and an oil cooler opening. The side duct 12 and the internal device opening side duct 14 are not shown.

  The motor 3 is horizontally installed in the center of the package 2 and incorporates a motor fan 3a facing the right side surface 2e of the package 2. The motor fan 3 a cools the motor 3 by sending air toward the main body of the motor 3. That is, the motor fan 3a blows air from the right side 2e side of the package 2 toward the left side 2f.

  The compressor body 4 is a two-stage compression compressor connected to the motor 3 on the left side surface 2f side of the package 2, and the first compressor 4a and the second compressor 4b respectively driven by the motor 3 are connected to the compressor body 4. Have. Lubricating oil circulated by an oil pump (not shown) is supplied to a drive system such as a gear and a bearing in the compressor body 4.

  The gas cooler 5 is disposed above the motor 3 in the package 2, and includes an intercooler 5 a and an aftercooler 5 b that face the upper surface 2 a of the package 2. The oil cooler 6 is disposed in the package 2 on the side of the motor 3 so as to face the back surface 2d of the package 2.

  The oil-free screw compressor 1 has an electromagnetic valve 7 as an internal device provided on the side of the motor 3 in the package 2. The internal device is not limited to the electromagnetic valve 7. The oil-free screw compressor 1 has an intake opening 8 and an exhaust opening 9 provided in the package 2.

  The exhaust opening 9 includes a first exhaust opening 9a that opens to the upper surface 2a of the package 2 above the intercooler 5a, and a second exhaust opening that opens to the upper surface 2a of the package 2 above the aftercooler 5b. 9b. The first exhaust opening 9a is provided adjacent to and above the intercooler 5a. The second exhaust opening 9b is provided adjacent to the upper portion of the aftercooler 5b.

On the other hand, the intake opening 8 includes an oil cooler opening (first opening) 8a that opens on the back surface 2d of the package 2 so as to face the oil cooler 6, and a right side surface of the package 2 below the motor fan 3a. A motor opening (second opening) 8b that opens to 2e, an internal device opening (third opening) 8c that opens to the back surface 2d of the package 2 below the oil cooler 6, and a fan 10 to be described later. The gas cooler opening (fourth opening) 8d opens on the right side surface 2e of the package 2 on the side of. The oil cooler opening 8 a is provided adjacent to the side of the oil cooler 6. The motor opening 8b is provided on the upstream side of the motor fan 3a. The internal device opening 8 c is provided downstream of the motor fan 3 a and upstream of the electromagnetic valve 7. The gas cooler opening 8 d is provided on the side of the fan 10. These openings 8a to 8d are all provided at locations away from the compressor body 4 that is a noise source.

  The oil-free screw compressor 1 has a fan 10 provided in the package 2. The fan 10 is disposed between the motor 3 and the gas cooler 5 and takes in cooling air from the intake opening 8 into the package 2 by blowing air from the bottom surface 2b side to the top surface 2a side of the package 2. Then, the air in the package 2 is discharged to the outside through the exhaust opening 9.

  The oil-free screw compressor 1 has an intake duct 11 that is provided in the package 2 and supplies air taken in from an intake opening that opens to the left side surface 2f of the package 2 to the first compressor 4a.

Further, as shown in FIG. 2, the oil-free screw compressor 1 has an oil cooler opening side duct (first opening side duct) provided between the oil cooler opening 8a and the compressor body 4. 12. The oil cooler opening side duct 12 is disposed adjacent to the oil cooler 6, and has an opening that contacts the oil cooler 6 as an inlet and an opening that faces the upper surface 2 a of the package 2 as an outlet. Therefore, as shown by the arrow, the cooling air taken in from the oil cooler opening 8a flows toward the upper surface 2a of the package 2 after passing through the oil cooler 6, thereby opening the oil cooler opening side duct. 12 passes through the fan 10. Further, the propagation of sound from the compressor body 4 toward the oil cooler opening 8a is blocked by the wall surface of the oil cooler opening side duct 12. In FIG. 2, illustration of the upper surface 2a, front surface 2c, back surface 2d, right side surface 2e, and left side surface 2f of the package 2 is omitted.

The oil-free screw compressor 1 has a motor opening side duct (second opening side duct) 13 provided between the motor opening 8b and the motor 3, as shown in FIG. ing. The motor opening side duct 13 is disposed adjacent to the right side surface 2e of the package 2, and has an intermediate outlet 13a that opens toward the front surface 2c (back side of the paper surface) of the package 2 with the motor opening 8b as an inlet. And an outlet 13b that opens toward the left side 2f (the right side of the page) of the package 2. Therefore, as shown by the arrow, the cooling air taken in from the motor opening 8b first flows toward the front surface 2c of the package 2 and exits the intermediate outlet 13a, and then toward the left side surface 2f of the package 2. By flowing, it passes through the motor opening side duct 13 and flows out from the outlet 13b. The flow of the cooling air flowing out from the outlet 13b is roughly divided into two, one flows into the fan 10 through the upper side of the motor 3, and the other passes through the lower side of the motor 3 to the electromagnetic valve 7 by the motor fan 3a. And then flows into the fan 10. Further, the propagation of sound from the motor 3 or the compressor body 4 toward the motor opening 8b is blocked by the wall surface of the motor opening duct 13. In FIG. 3, the back surface 2d of the package 2, the oil cooler 6, and the oil cooler opening side duct 12 are not shown.

Also, oil-free screw compressor 1 has an internal device opening duct (third opening duct) 14 provided et the between the compressor body 4 and the opening 8c for internal equipment . The internal device opening side duct 14 is disposed adjacent to the back surface 2d of the package 2, and the internal device opening 8c is used as an inlet, and an outlet 14a opened toward the upper surface 2a (upper side of the sheet) of the package 2 is provided. Have. Therefore, the cooling air taken in from the opening 8c for the internal device flows toward the front surface 2c of the package 2 and then flows toward the upper surface 2a of the package 2 as indicated by an arrow, thereby It passes through the opening side duct 14 and flows out from the outlet 14a. The cooling air flowing out from the outlet 14a is moved toward the solenoid valve 7 by the motor fan 3a and then flows into the fan 10. The propagation of sound from the compressor body 4 toward the internal device opening 8c is blocked by the wall surface of the internal device opening side duct 14.

  As shown in FIG. 4, the fan 10 is attached to a propeller-shaped fan main body 10a rotated by a motor (not shown), a steel fan cover 10b surrounding the fan main body 10a, and an inner surface of the fan cover 10b. You may have the sound-absorbing material 10c which consists of the worn urethane foam etc. By surrounding the fan body 10a with a fan cover 10b with a sound absorbing material 10c, noise from the fan body 10a is reduced. As a result, noise leaking to the outside from the exhaust opening 9, the oil cooler opening 8a, and the gas cooler opening 8d is reduced.

(Operation of oil-free screw compressor)
Next, the operation of the oil-free screw compressor 1 will be described. When the oil-free screw compressor 1 is operated, air is supplied to the first compressor 4a through the intake duct 11 as shown in FIG. The air supplied to the first compressor 4a is compressed by the first compressor 4a, sent to the intercooler 5a, and cooled by the intercooler 5a. Thereafter, this air is supplied to the second compressor 4b and further compressed by the second compressor 4b. Then, this air is sent to the aftercooler 5b, cooled by the aftercooler 5b, and then discharged to the outside of the package 2 through an exhaust port (not shown). The lubricating oil supplied to the drive system such as gears and bearings in the compressor body 4 is circulated by an oil pump (not shown), cooled by the oil cooler 6, and then supplied to the drive system again.

  While the oil-free screw compressor 1 is in operation, the fan 10 is rotated so that cooling air is taken into the package 2 from the intake opening 8 and the air in the package 2 is discharged to the outside through the exhaust opening 9. Is done. Heat sources such as the motor 3, the oil cooler 6, the gas cooler 5, and the electromagnetic valve 7 are cooled by this air flow.

  Here, in this embodiment, as shown in FIG. 2, the oil cooler opening 8 a is provided in the vicinity of the oil cooler 6. Specifically, the oil cooler opening 8 a is provided adjacent to the side of the oil cooler 6. Therefore, as shown by the arrows, the cooling air taken into the package 2 from the oil cooler opening 8a is pulled by the fan 10, so that the oil cooler 6, the oil cooler opening side duct 12, the fan 10, It passes through the gas cooler 5 in this order and is discharged to the outside from the exhaust opening 9. Accordingly, the cooling air taken into the package 2 from the oil cooler opening 8a mainly cools the oil cooler 6 and is discharged to the outside through the exhaust opening 9.

  As shown in FIG. 3, the motor opening 8b is provided on the upstream side of the motor fan 3a. Therefore, as indicated by an arrow, the cooling air taken into the package 2 from the motor opening 8b is first pulled by the motor fan 3a after passing through the motor opening-side duct 13, and then by the fan 10. By being pulled, the motor fan 3a, the motor 3, the fan 10, and the gas cooler 5 are passed through in this order and discharged from the exhaust opening 9 to the outside. As a result, the cooling air taken into the package 2 from the motor opening 8b mainly cools the motor 3 and is discharged to the outside through the exhaust opening 9.

  The internal device opening 8 c is provided on the downstream side of the motor fan 3 a and on the upstream side of the electromagnetic valve 7. Therefore, as indicated by the arrows, the cooling air taken into the package 2 from the internal device opening 8c passes through the internal device opening side duct 14, and then is driven by the force of the exhaust air generated by the motor fan 3a. 7 and flows through the solenoid valve 7, the fan 10, and the gas cooler 5 in this order, and is discharged to the outside from the exhaust opening 9. Thus, the cooling air taken into the package 2 from the internal device opening 8c mainly cools the electromagnetic valve 7 and is discharged to the outside through the exhaust opening 9.

  The gas cooler opening 8 d is provided on the side of the fan 10. Therefore, as indicated by an arrow, the cooling air taken into the package 2 from the gas cooler opening 8d is pulled by the fan 10 and passes through the fan 10 and the gas cooler 5 in this order from the exhaust opening 9. It is discharged outside. Thereby, the cooling air taken into the package 2 from the gas cooler opening 8d mainly cools the gas cooler 5 and is discharged to the outside through the exhaust opening 9.

  As described above, the package 2 mainly includes an oil cooler opening 8 a for cooling the oil cooler 6, a motor opening 8 b for mainly cooling the motor 3, and mainly for cooling the electromagnetic valve 7. The internal device opening 8c and the gas cooler opening 8d mainly for cooling the gas cooler 5 are provided, so that the oil cooler 6, the motor 3, the electromagnetic valve 7, and the gas cooler 5 as heat sources are provided. Each can be suitably cooled. Since the intake opening 8 is divided into four parts, namely, an oil cooler opening 8a, a motor opening 8b, an internal device opening 8c, and a gas cooler opening 8d, the intake opening 8 It is possible to disperse and reduce noise emitted from each opening while ensuring a sufficient opening area as a whole. Thereby, the heat source can be sufficiently cooled while reducing noise leaking to the outside.

  Further, by providing the oil cooler opening 8a in the vicinity of the oil cooler 6, the oil cooler 6 can be suitably cooled by the cooling air taken into the package 2 from the oil cooler opening 8a.

  Further, by providing the internal device opening 8c on the downstream side of the motor fan 3a and upstream of the electromagnetic valve 7, the cooling air taken into the package 2 from the internal device opening 8c is generated by the motor fan 3a. It can be made to flow toward the solenoid valve 7 by the force of the exhaust air. Thereby, the solenoid valve 7 can be suitably cooled by the cooling air taken into the package 2 from the opening 8c for internal devices.

  Further, by providing the exhaust opening 9 in the vicinity of the gas cooler 5, the gas cooler 5 can be suitably cooled by the air discharged from the exhaust opening 9 to the outside.

  Further, by using the motor fan 3a built in the motor 3, the cost can be reduced and the package 2 can be made compact.

  Further, the oil cooler opening side duct 12 provided between the oil cooler opening 8a and the compressor body 4 blocks the propagation of sound from the compressor body 4 toward the oil cooler opening 8a. Thereby, since the noise from the compressor main body 4 does not leak directly from the opening part 8a for oil coolers, the noise leaking outside can be reduced. Further, since the compressor body 4 is removed from the air path as a noise propagation path, the noise from the compressor body 4 as a noise source is not easily emitted from the exhaust opening 9.

  The motor opening side duct 13 provided between the motor opening 8b and the motor 3 blocks the propagation of sound from the motor 3 toward the motor opening 8b. Thereby, since the noise from the motor 3 does not leak directly from the motor opening 8b, the noise leaking to the outside can be reduced.

  Further, the internal device opening side duct 14 provided between the internal device opening 8c and the compressor main body 4 blocks the propagation of sound from the compressor main body 4 toward the internal device opening 8c. Thereby, since the noise from the compressor main body 4 does not leak directly from the opening part 8c for internal apparatuses, the noise which leaks outside can be reduced. Further, the end of the internal device opening side duct 14 opposite to the internal device opening 8c is positioned downstream of the motor fan 3a and is less influenced by the flow of the fan 10 (for example, the motor 3 and the bottom surface 2b of the package 2), the cooling air taken in from the internal device opening 8c can be easily flowed to the electromagnetic valve 7 side.

  Here, since the cooling air taken into the package 2 from the motor opening 8b is drawn into the package 2 by the motor fan 3a, the air volume tends to increase. Therefore, in order to sufficiently cool not only the motor 3 and the electromagnetic valve 7 but also the oil cooler 6 and the gas cooler 5, the sum of the opening area of the motor opening 8b and the opening area of the internal device opening 8c is: The sum of the opening area of the oil cooler opening 8a and the opening area of the gas cooler opening 8d is relatively smaller than 1/3 or less of the opening area of the entire intake opening 8. 8 is larger than 2/3 of the total opening area. By doing so, the air volume of the cooling air taken into the package 2 from the oil cooler opening 8a and the gas cooler opening 8d is reduced to 1 / of the air volume of the cooling air taken into the package 2 from the entire intake opening 8. The air volume of the cooling air taken into the package 2 from the motor opening 8b and the internal device opening 8c is ½ of the air volume of the cooling air taken into the package 2 from the entire intake opening 8 Since it becomes the following, each heat source can be cooled suitably.

  In addition, since the intake opening 8 is divided into four parts, an oil cooler opening 8a, a motor opening 8b, an internal device opening 8c, and a gas cooler opening 8d, noise leakage is particularly large. If noise countermeasures are taken only at the opening, noise leaking to the outside can be easily reduced. In addition, since the cooling air taken in from the openings 8a to 8d is configured to intensively cool one of the heat sources, the opening of the opening that takes in the cooling air mainly for cooling the heat source that particularly needs to be cooled. If the area is increased to improve the cooling performance and noise measures are taken at the opening, it is easy to maintain a constant amount of noise leaking outside while improving the cooling performance.

(Evaluation of noise reduction)
Next, the amount of noise reduction was evaluated with the oil-free screw compressor 1 of the present embodiment and the conventional machine. There are some structural differences between the oil-free screw compressor 1 of the present embodiment and the conventional machine, and these differences contribute to noise reduction.

  First, the difference between the oil-free screw compressor 1 of the present embodiment and the conventional machine will be described with reference to FIG. In the conventional machine, the internal device opening 8c is provided at a position facing the compressor body 4 on the back surface 2d, whereas in the oil-free screw compressor 1 of the present embodiment, the internal device opening 8c. Is provided downstream of the motor fan 3 a and upstream of the electromagnetic valve 7. In the conventional machine, the intake port communicating with the intake duct 11 is provided in the back surface 2d, whereas in the oil-free screw compressor 1 of the present embodiment, the intake port is provided in the left side surface 2f. Further, in the conventional machine, the gas cooler opening 8d is not provided.

  Table 1 shows the results of evaluating the amount of noise reduction between the oil-free screw compressor 1 of the present embodiment and the conventional machine. Here, the evaluation point refers to a portion having a height of 1 m that is 1.5 m away from each surface of the package 2.

  In the conventional machine, the noise from the back surface 2d provided with the oil cooler opening 8a and the internal equipment opening 8c was loud, whereas in the oil-free screw compressor 1 of the present embodiment, the oil cooler opening By providing the oil cooler opening side duct 12 in the portion 8a and the internal device opening side duct 14 in the internal device opening 8c, noise is reduced by about 9 dB from the conventional machine at the rear evaluation point. In the oil-free screw compressor 1 of the present embodiment, the layout of each opening is optimized, and the fan opening 10 with the motor opening side duct 13 and the sound absorbing material 10c is provided. The noise is also lower than the previous model. In particular, even when the gas cooler opening 8d, which was not provided in the conventional machine, is provided on the right side 2e, the noise does not deteriorate at the right side evaluation point, and the noise is reduced on the 65 kW machine.

(effect)
As described above, according to the oil-free screw compressor 1 according to the present embodiment, the cooling air taken into the package 2 from the oil cooler opening 8a mainly cools the oil cooler 6 and is used for exhaust. It is discharged from the opening 9 to the outside. The cooling air taken into the package 2 from the motor opening 8b mainly cools the motor 3 and is discharged to the outside through the exhaust opening 9. The cooling air taken into the package 2 from the internal device opening 8c mainly cools the electromagnetic valve 7 and is discharged to the outside through the exhaust opening 9. The cooling air taken into the package 2 from the gas cooler opening 8d mainly cools the gas cooler 5 and is discharged to the outside through the exhaust opening 9. As described above, the package 2 mainly includes an oil cooler opening 8 a for cooling the oil cooler 6, a motor opening 8 b for mainly cooling the motor 3, and mainly for cooling the electromagnetic valve 7. The internal device opening 8c and the gas cooler opening 8d mainly for cooling the gas cooler 5 are provided, so that the oil cooler 6, the motor 3, the electromagnetic valve 7, and the gas cooler 5 as heat sources are provided. Each can be suitably cooled. Since the intake opening 8 is divided into four parts, namely, an oil cooler opening 8a, a motor opening 8b, an internal device opening 8c, and a gas cooler opening 8d, the intake opening 8 The noise emitted from each of the openings 8a to 8d can be dispersed and reduced while sufficiently securing the overall opening area. Thereby, the heat source can be sufficiently cooled while reducing noise leaking to the outside.

  Moreover, since the cooling air taken into the package 2 from the motor opening 8b is drawn into the package 2 by the motor fan 3a, the air volume tends to increase. Therefore, the sum of the opening area of the motor opening 8b and the opening area of the internal device opening 8c is set to be smaller than 1/3 of the entire opening area of the intake opening 8 and is relatively used for the oil cooler. The sum of the opening area of the opening 8a and the opening area of the gas cooler opening 8d is set to be larger than 2/3 of the entire opening area of the intake opening 8 so that the openings 8a to 8d can enter the package 2 from the openings 8a to 8d. Each heat source can be suitably cooled by adjusting the air volume of the cooling air taken in.

  Further, by providing the oil cooler opening 8a in the vicinity of the oil cooler 6, the oil cooler 6 can be suitably cooled by the cooling air taken into the package 2 from the oil cooler opening 8a.

  Further, by providing the internal device opening 8c on the downstream side of the motor fan 3a and upstream of the electromagnetic valve 7, the cooling air taken into the package 2 from the internal device opening 8c is generated by the motor fan 3a. It can be made to flow toward the solenoid valve 7 by the force of the exhaust air. Thereby, the solenoid valve 7 can be suitably cooled by the cooling air taken into the package 2 from the opening 8c for internal devices.

  Further, by providing the exhaust opening 9 in the vicinity of the gas cooler 5, the gas cooler 5 can be suitably cooled by the air discharged from the exhaust opening 9 to the outside.

  Further, by using the motor fan 3a built in the motor 3, the cost can be reduced and the package 2 can be made compact.

  Further, the oil cooler opening side duct 12 provided between the oil cooler opening 8a and the compressor body 4 blocks the propagation of sound from the compressor body 4 toward the oil cooler opening 8a. Thereby, since the noise from the compressor main body 4 does not leak directly from the opening part 8a for oil coolers, the noise leaking outside can be reduced.

  The motor opening side duct 13 provided between the motor opening 8b and the motor 3 blocks the propagation of sound from the motor 3 toward the motor opening 8b. Thereby, since the noise from the motor 3 does not leak directly from the motor opening 8b, the noise leaking to the outside can be reduced.

  Further, the internal device opening side duct 14 provided between the internal device opening 8c and the compressor main body 4 blocks the propagation of sound from the compressor main body 4 toward the internal device opening 8c. Thereby, since the noise from the compressor main body 4 does not leak directly from the opening part 8c for internal apparatuses, the noise which leaks outside can be reduced.

(Modification of this embodiment)
The embodiment of the present invention has been described above, but only specific examples are illustrated, and the present invention is not particularly limited, and the specific configuration and the like can be appropriately changed in design. Further, the actions and effects described in the embodiments of the invention only list the most preferable actions and effects resulting from the present invention, and the actions and effects according to the present invention are described in the embodiments of the present invention. It is not limited to what was done.

  For example, although the gas cooler opening 8d is provided on the right side surface 2e of the package 2, the gas cooler opening 8d may not be provided.

DESCRIPTION OF SYMBOLS 1 Oil free screw compressor 2 Package 2a Upper surface 2b Bottom surface 2c Front surface 2d Rear surface 2e Right side surface 2f Left side surface 3 Motor 3a Motor fan 4 Compressor body 4a 1st compressor 4b 2nd compressor 5 Gas cooler 5a Intercooler 5b After cooler 6 Oil cooler 7 Solenoid valve 8 Intake opening 8a Oil cooler opening 8b Motor opening 8c Internal device opening 8d Gas cooler opening 9 Exhaust opening 9a First exhaust opening 9b Second exhaust opening Part 10 Fan 10a Fan body 10b Fan cover 10c Sound absorbing material 11 Air intake duct 12 Oil cooler opening side duct 13 Motor opening side duct 14 Internal equipment opening side duct

Claims (10)

An oil-free screw compressor that cools air compressed by a compressor body driven by a motor with a gas cooler and cools lubricating oil used in the drive system of the compressor body with an oil cooler,
A package containing the motor, the compressor body, the gas cooler, and the oil cooler;
An internal device provided in the package;
An intake opening provided in the package;
An exhaust opening provided in the package;
A fan that is provided in the package, takes cooling air into the package from the intake opening, and discharges the air in the package to the outside from the exhaust opening;
A motor fan for cooling the motor;
Have
The intake opening includes at least three openings, a first opening, a second opening, and a third opening ,
Cooling air taken into the package from the first opening is exhausted from the exhaust opening through the oil cooler, the fan, and the gas cooler in this order,
Cooling air taken into the package from the second opening is exhausted from the exhaust opening through the motor fan, the motor, the fan, and the gas cooler in this order,
Cooling air taken into the package from the third opening passes through the internal device, the fan, and the gas cooler in this order and is discharged to the outside from the exhaust opening. Screw compressor. The intake opening includes four openings, the first opening, the second opening, the third opening, and the fourth opening .
The cooling air taken into the package from the fourth opening is discharged to the outside from the exhaust opening through the fan and the gas cooler in this order. Oil-free screw compressor. The total of the opening area of the second opening and the opening area of the third opening is 1/3 or less of the entire opening area of the intake opening. Oil-free screw compressor. The oil-free screw compressor according to any one of claims 1 to 3, wherein the first opening is provided in the vicinity of the oil cooler. 5. The oil-free screw compression according to claim 1, wherein the third opening is provided downstream of the motor fan and upstream of the internal device. Machine.   The oil-free screw compressor according to any one of claims 1 to 5, wherein the exhaust opening is provided in the vicinity of the gas cooler.   The oil-free screw compressor according to any one of claims 1 to 6, wherein the motor fan is built in the motor. Provided between the first opening and the compressor body, the cooling air taken in from the first opening passes and blocks the propagation of sound from the compressor body toward the first opening. The oil-free screw compressor according to any one of claims 1 to 7, further comprising a first opening side duct. Provided between the second opening motor, together with the cooling air taken in from the second opening passes, the second opening for blocking the propagation of sound toward the second opening from the motor The oil-free screw compressor according to any one of claims 1 to 8, further comprising a side duct. Provided between the third opening and the compressor body, the cooling air taken in from the third opening passes and blocks the propagation of sound from the compressor body toward the third opening. The oil-free screw compressor according to any one of claims 1 to 9, further comprising a third opening side duct.

Images