JP2011027113A - Screw compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw compressor capable of adopting a motor with a relatively low rotational speed while suppressing an increase in a diameter of a gear, and thus, reducing costs. <P>SOLUTION: The screw compressor includes pinion gears 12, 14 arranged in a male rotor 2a of a low pressure stage compressor body 2 and a male rotor 3a of a high pressure stage compressor body 3, respectively, a bull gear 10 arranged at a rotary shaft 4a of a motor 4, an intermediate shaft 16 supported so as to be turnable and having a pinion gear 19 meshed with the bull gear 10 and a bull gear 20 meshed with the pinion gears 12, 14, a gear casing 5, a first cooling device 23 cooling compressed air from the low pressure stage compressor body 2, and a second cooling device 24 cooling compressed air from the high pressure stage compressor body 3. The motor 4, the gear casing 5, the low pressure stage compressor body 2, and the high pressure stage compressor body 3 are arranged in the central part of a compressor unit, and the first cooling device 23 and the second cooling device 24 are arranged at one side and at the other side in the longitudinal width direction of the compressor unit. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a screw compressor, and more particularly to a screw compressor that generates large-capacity compressed air.

  The screw compressor includes a male rotor and a female rotor that rotate so that their rotational axes are parallel and mesh with helical teeth, and a casing that houses these male and female rotors. A plurality of compression working chambers are formed by the tooth gap and the inner wall of the casing. While these compression working chambers move in the axial direction along with the rotation of the male rotor and the female rotor, their volumes are reduced to compress the air.

  Conventionally, for example, as a two-stage screw compressor, a low-pressure stage compressor body, an intercooler that cools the compressed air from the low-pressure stage compressor body, and a high-pressure that further compresses the compressed air cooled by the intercooler The structure provided with the stage compressor main body and the aftercooler which cools the compressed air from this high pressure stage compressor main body is disclosed (for example, refer patent document 1). In this prior art, pinion gears are respectively attached to the rotor shafts (one of the male rotor and the female rotor) of the low-pressure stage compressor body and the high-pressure stage compressor body, and these pinion gears are the rotation shafts of the motor (electric motor). It is designed to mesh with the bull gears attached to each. As the motor is driven, the rotational power of the motor is increased and transmitted through the bull gear and the pinion gear, so that the low-pressure stage compressor body and the high-pressure stage compressor body are driven.

JP 2002-155879 A

However, the above prior art has room for improvement as follows.
That is, in the above prior art, the speed increase ratio is determined by the ratio of the meshing pitch diameter of the bull gear on the motor side and the meshing pitch diameter of the pinion gear on the compressor body side, and the rotational power of the motor is determined according to this speed ratio. Are increased in speed in one stage and transmitted to drive the low-pressure compressor main body and the high-pressure compressor main body, respectively. Therefore, for example, in a large-capacity compressor unit with an output of several hundred kw, the diameter of the bull gear on the motor side is increased corresponding to the pinion gear on the compressor body side in order to obtain a predetermined speed increase ratio, or It was necessary to reduce the speed increasing ratio and increase the rotation speed of the motor. When the diameter of the gear is increased, it may be difficult to manufacture due to a problem in manufacturing equipment (for example, the limit of the processing range of a machine tool). As a result, the cost of the gear or motor has increased.

  An object of the present invention is to provide a screw compressor that can be a motor having a relatively low rotation speed while suppressing an increase in the diameter of a gear, and thereby can reduce costs.

  (1) To achieve the above object, the present invention provides a low-pressure stage compressor body, a high-pressure stage compressor body that further compresses compressed air compressed by the low-pressure stage compressor body, and the low-pressure stage compressor body. And a plurality of rotor-side gears respectively provided on the rotor shaft of the high-pressure compressor main body, a motor, and a motor-side gear provided on the rotation shaft of the motor are rotatably supported and meshed with the motor-side gear. An intermediate shaft provided with a first speed increasing gear and a second speed increasing gear meshing with the plurality of rotor side gears, the motor side gear, the first speed increasing gear, the intermediate shaft, and a second speed increasing Gear casing for housing the gear for the rotor and the gear on the rotor side, a first cooling device for cooling the compressed air from the low pressure stage compressor body, and a second for cooling the compressed air from the high pressure stage compressor body A cooling device, and the motor and gear Sing, a low-pressure stage compressor main body, and a high-pressure stage compressor main body are arranged at a central portion of the compressor unit, the first cooling device is arranged on one side in the longitudinal width direction of the compressor unit, and the second Is arranged on the other side in the longitudinal width direction of the compressor unit.

  (2) In the above (1), preferably, the rotation shaft of the motor and the rotor shafts of the low-pressure compressor main body and the high-pressure compressor main body are parallel to each other and the axial direction thereof is the short width direction of the compressor unit. The motor, the low-pressure stage compressor main body, and the high-pressure stage compressor main body are vertically arranged on one side in the axial direction.

  (3) In the above (2), preferably, the low-pressure stage compressor body is disposed on one side in the longitudinal width direction of the compressor unit in the gear casing, and the high-pressure stage compressor body is the gear casing. Is disposed on the other side in the longitudinal width direction of the compressor unit.

  (4) In any one of the above (1) to (3), preferably, the first and second cooling devices include a duct provided in a substantially vertical direction and a cooling air provided in the duct. The generated cooling fan and the heat exchange for the compressed air that is arranged on the upstream side of the cooling fan in the duct and exchanges heat with the cooling air to cool the compressed air from the low-pressure compressor main body or the high-pressure compressor main body. Each with a vessel.

  (5) In the above (4), preferably, the duct is connected to an intake port and an exhaust port of the compressor unit, and an intake space is formed between the intake port and the heat exchanger for compressed air. An exhaust space is formed between the cooling fan and the exhaust port.

  Thus, for example, compared with a case where no intake space is formed between the intake port and the heat exchanger for compressed air or an exhaust space is not formed between the cooling fan and the exhaust port, a heat exchanger for compressed air is used. The leakage of generated noise can be reduced.

  (6) In the above (4), and preferably, either one or both of the first and second cooling devices are provided with a plurality of compressed air heat exchangers, and the plurality of compressed air heat exchanges. A vessel is arranged in parallel with the flow of cooling air in the duct.

  (7) In the above (6), preferably, a plurality of the cooling fans are provided so as to form a pair with the plurality of heat exchangers, and are arranged in parallel.

  (8) In the above (6), preferably, the plurality of compressed air heat exchangers are arranged in parallel in a short width direction of the compressor unit.

  (9) In the above (4), preferably, the heat exchanger for compressed air is provided so as to be inclined with respect to the flow of the cooling air in the vertical direction in the duct.

  Thus, the width direction dimension of a compressor unit can be shortened by inclining the heat exchanger for compressed air.

  (10) In the above (4), and preferably, either one or both of the first and second cooling devices are provided with a plurality of compressed air heat exchangers, and the plurality of compressed air heat exchanges. A heat exchanger for oil is provided between the plurality of heat exchangers for compressed air, and the heat exchanger is arranged in parallel so as to be inclined with respect to the flow of the cooling air in the vertical direction in the duct.

  According to the present invention, it is possible to obtain a motor having a relatively low rotational speed while suppressing an increase in the diameter of the gear, thereby reducing costs.

It is a top view showing the structure of 1st Embodiment of the screw compressor of this invention. It is the side view seen from the arrow II direction in FIG. It is the side view seen from the arrow III direction in FIG. It is side surface sectional drawing by the cross section IV-IV in FIG. It is side surface sectional drawing by the cross section VV in FIG. It is an upper surface perspective view of the compressor unit showing the structure of 2nd Embodiment of the screw compressor of this invention. It is an upper surface see-through | perspective side view of the compressor unit showing the structure of 2nd Embodiment of the screw compressor of this invention. FIG. 8 is a side perspective view of the compressor unit as seen from the direction of arrow VIII in FIG. 6. FIG. 7 is a side perspective view of the compressor unit as seen from the direction of arrow IX in FIG. 6. It is side surface perspective drawing of the 1st cooling device seen from the arrow X direction in FIG. It is side surface perspective drawing of the 2nd cooling device seen from the arrow XI direction in FIG.

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

A first embodiment of the present invention will be described with reference to FIGS.
1 is a top view showing the configuration of the screw compressor according to the present embodiment, FIG. 2 is a side view seen from the direction of arrow II in FIG. 1, and FIG. 3 is seen from the direction of arrow III in FIG. 4 is a side sectional view taken along section IV-IV in FIG. 1. FIG. 5 is a side sectional view taken along section V-V in FIG. 1 (however, only the inside of the gear casing is shown). is there.

  1 to 5, a low-pressure compressor main body 2 that compresses air sucked through a suction throttle valve 1 (not shown in the present embodiment, refer to the drawings described later) to a predetermined intermediate pressure, and the low pressure A high pressure stage compressor body 3 that compresses the compressed air compressed by the stage compressor body 2 to a predetermined discharge pressure, a motor (electric motor) 4, and the rotational power of the motor 4 is reduced to the low pressure stage compressor body 2 and the high pressure. A gear casing 5 that houses a gear mechanism (details will be described later) for transmitting to the stage compressor body 3 is provided. An oil sump (not shown) is provided in the lower part of the gear casing 5.

  The motor 4 is fixed to a motor mount 6, and the motor mount 6 is mounted on a base 7 via a plurality of vibration isolating rubbers 8. The rotating shaft 4a of the motor 4 includes, for example, a radial bearing 4b provided on the load side (right side in FIG. 2, left side in FIG. 3) and, for example, a thrust bearing provided on the non-load side (left side in FIG. 2, right side in FIG. 3). 4c and is rotatably supported via 4c. The flange 4d of the motor 4 is fixed to the side surface of one side (the lower side in FIG. 1, the left side in FIG. 2, the right side in FIG. 3) of the gear casing 5 with a bolt 9. An opening is formed on one side surface of the gear casing 5 so as to correspond to the flange 4d of the motor 4. A bull gear is provided at the tip of the rotating shaft 4a of the motor 4 in the gear casing 5 inserted through the opening. 10 is fitted.

  The low-pressure compressor body 2 is, for example, an oil-free screw compressor (operating in a compression working chamber without oil supply), and has a male rotor 2a that rotates so that its rotation axis is parallel and helical teeth mesh with each other. And a female rotor 2b, and a timing gear (not shown) is fitted to one end (the lower side in FIG. 1, the left side in FIG. 2) of each of the male rotor 2a and the female rotor 2b. Yes. Thereby, the male rotor 2a and the female rotor 2b rotate without contact and without lubrication. The flange 2c of the low-pressure stage compressor body 2 is fixed to the one side surface of the gear casing 5 with bolts 11 so as to be positioned above the flange 4d of the motor 4 (upper side in FIGS. 2 to 4). At this time, the male rotor 2a is disposed on the inner side (left side in FIG. 4) and the female rotor 2b is disposed on the outer side (right side in FIG. 4) so as to be parallel to the rotation shaft 4a of the motor 4. Further, an opening is formed on one side surface of the gear casing 5 corresponding to the flange 2c of the low-pressure stage compressor body 2, and the other side of, for example, the male rotor 2a inserted through the opening (in FIG. 1). A pinion gear 12 is fitted to the front end (upper side, right side in FIG. 2).

  Similarly, the high-pressure stage compressor body 3 is, for example, an oil-free screw compressor, and includes a male rotor 3a and a female rotor 3b that rotate so that the rotation axes are parallel and the helical teeth mesh with each other. Timing gears (not shown) are respectively fitted to one end (the lower side in FIG. 1, the right side in FIG. 3) of the male rotor 3a and the female rotor 3b. Thereby, the male rotor 3a and the female rotor 3b rotate without contact and without lubrication. The flange 3 c of the high-pressure compressor main body 3 is fixed to the one side surface of the gear casing 5 with a bolt 13 so as to be positioned above the flange 4 d of the motor 4. At this time, the male rotor 3a is disposed on the inner side (right side in FIG. 4) and the female rotor 3b is disposed on the outer side (left side in FIG. 4) so as to be parallel to the rotation shaft 4a of the motor 4. Further, an opening is formed on one side surface of the gear casing 5 corresponding to the flange 3c of the high-pressure compressor main body 3, and the other side of the male rotor 3a (for example, in FIG. 1) inserted through this opening. A pinion gear 14 is fitted to the tip (upper side, left side in FIG. 3).

  In the gear casing 5, for example, an intermediate shaft 16 that is rotatably supported via a thrust bearing 15 </ b> A and a radial bearing 15 </ b> B is provided. The intermediate shaft 16 includes a rotating shaft 4 a of the motor 4, a low-pressure compressor. It is parallel to the male rotor 2a of the main body 2 and the male rotor 3a of the high-pressure compressor main body 3. The radial bearing 15B is provided, for example, on one side surface of the gear casing, and the thrust bearing 15A is, for example, a bearing support attached to the side surface opposite to the gear casing 5 (upper side in FIG. 1, right side in FIG. 2, left side in FIG. 3). The unit 17 is provided. A cover 18 is attached to the bearing support portion 17.

  The intermediate shaft 16 includes a pinion gear 19 (first speed increasing gear) that meshes with the bull gear 10 of the rotating shaft 4a of the motor 4, the pinion gear 12 of the male rotor 2a of the low pressure stage compressor body 2, and the high pressure stage compressor. A bull gear 20 (second speed increasing gear) that meshes with the pinion gear 14 of the male rotor 3a of the main body 3 is fitted. The meshing pitch diameter of the pinion gear 19 of the intermediate shaft 16 is smaller than the meshing pitch diameter of the bull gear 10 of the rotating shaft 4 a of the motor 4, and the rotational power of the rotating shaft 4 a of the motor 4 via these bull gear 10 and the pinion gear 19. Is increased and transmitted to the intermediate shaft 16. Further, the meshing pitch diameter of the bull gear 20 of the intermediate shaft 16 is the meshing pitch diameter of the pinion gear 12 of the male rotor 2a of the low pressure stage compressor body 2 and the meshing of the pinion gear 14 of the male rotor 3a of the high pressure stage compressor body 3. The rotational diameter of the intermediate shaft 16 is increased through the bull gear 20 and the pinion gears 12 and 14 through the bull gear 20 and the pinion gears 12 and 14, and the male rotor 2a of the low-pressure stage compressor body 2 and the male rotor 3a of the high-pressure stage compressor body 3 Is transmitted to each.

  As described above, in the present embodiment, the pinion gear 19 that meshes with the bull gear 10 provided on the rotating shaft 4 a of the motor 4, the pinion gear 12 provided on the male rotor 2 a of the low pressure stage compressor body 2, and the high pressure stage compressor body 3. An intermediate shaft 16 including a bull gear 20 that meshes with a pinion gear 14 provided on the male rotor 3a is provided. The rotational power of the rotating shaft 4a of the motor 4 is increased in two stages by the speed increasing ratio between the bull gear 10 and the pinion gear 19 and the speed increasing ratio between the bull gear 20 and the pinion gear 12 (or the bull gear 20 and the pinion gear 14). To rotate the male rotor 2a of the low-pressure stage compressor body 2 (or the male rotor 3a of the high-pressure stage compressor body 3).

  Thereby, for example, compared with the case where the bull gear provided on the rotating shaft 4a of the motor 4 and the pinion gear provided on each of the male rotors 2a and 3a mesh with each other to increase the speed in one step, the increase in the diameter of the gear is suppressed. The motor 4 having a relatively low rotational speed can be obtained. That is, for example, in a compressor unit having a large capacity of several hundreds kw, even when the size of the gear is limited due to a problem in manufacturing equipment, it can be easily manufactured. For example, a 4-pole motor can be used as the motor 4 having a relatively low rotational speed. Therefore, cost can be reduced.

  Moreover, the enlargement of the gear casing 5 can be suppressed by suppressing the increase in the diameter of the gear. Moreover, by reducing the rotational speed of the motor 4, the load can be reduced and the reliability of components such as bearings can be improved.

  Further, by providing the motor 4, the low-pressure stage compressor body 2, and the high-pressure stage compressor body 3 on one side surface of the gear casing 5 (in other words, one side in the axial direction of the rotating shaft 4a and the male rotors 2a and 3a). For example, compared with the case where the motor 4 is disposed on one side surface of the gear casing 5 and the low-pressure stage compressor body 2 and the high-pressure stage compressor body 3 are disposed on the opposite side surface, the motor 4 and the low-pressure stage compressor body. 2 and the overall axial dimension of the high-pressure compressor body 3 and the like can be shortened. Therefore, it is possible to increase the degree of freedom of arrangement layout in a compressor unit (see the second embodiment) described later.

  A second embodiment of the present invention will be described with reference to FIGS. The present embodiment is an embodiment of a compressor unit equipped with the first embodiment.

  FIG. 6 is a top perspective view of the compressor unit representing the configuration of the screw compressor according to the present embodiment (however, for convenience, a cooling fan, a fan motor, and an oil cooler are not shown), and a compressed air system is illustrated. FIG. 7 is a top perspective view of the compressor unit representing the configuration of the screw compressor according to the present embodiment (however, for the sake of convenience, the suction throttle valve, the cooling fan, and the fan motor are not shown), and the oil system is illustrated. Yes. 8 is a side perspective view of the compressor unit viewed from the direction of arrow VIII in FIG. 5 and illustrates the compressed air system and the oil system. FIG. 9 is a compressor unit viewed from the direction of arrow IX in FIG. The side air perspective view (however, the suction throttle valve is not shown for convenience) shows the compressed air system. 10 is a side perspective view of the first cooling device viewed from the direction of arrow X in FIG. 5, and FIG. 11 is a side perspective view of the second cooling device viewed from the direction of arrow XI in FIG. However, for convenience, the supply piping is not shown). 6 to 11, parts equivalent to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  In the present embodiment, for example, a large capacity type (output is about several hundred kW) compressor unit 21 is a package type compressor unit covered with a soundproof cover 22 or the like, and includes the motor 4, gear casing 5, low pressure stage. A compressor main body 2 and a high-pressure stage compressor main body 3 are installed at the center of the base 7. As described in the first embodiment, since the overall axial dimension of the motor 4, the low-pressure stage compressor body 2, the high-pressure stage compressor body 3 and the like is relatively short, the motor 4 The axial direction of the rotary shaft 4a, the male rotor 2a and the female rotor 2b of the low-pressure compressor body 2 and the male rotor 3a and the female rotor 3b of the high-pressure compressor body 3 is the short width direction of the compressor unit 21 (see FIG. 6 and the vertical direction in FIG. 7. That is, even in such an arrangement, the transverse width dimension W of the compressor unit 21 can be made relatively short.

  Then, the motor 4, the gear casing 5, the low-pressure stage compressor body 2, the high-pressure stage compressor body 3, and the like are sandwiched between one side in the longitudinal width direction of the compressor unit 21 (right side in FIGS. 6 to 8, in FIG. 9). On the left side, a first cooling device 23 for cooling the compressed air from the low-pressure stage compressor body 2 is installed on the base 7, and the other side in the longitudinal width direction of the compressor unit 21 (left side in FIGS. 6 to 8). In the right side in FIG. 9, a second cooling device 24 for cooling the compressed air from the high-pressure compressor body 3 is installed on the base 7. As described above, by separately separating and arranging the first cooling device 23 and the second cooling device 24, the devices in the compressor unit 21 can be arranged efficiently and in a balanced manner.

  The low-pressure stage compressor body 2 is disposed on one side in the longitudinal width direction of the compressor unit 21 in the gear casing 5. Thereby, the connection piping (the discharge piping 25 etc. mentioned later) between the low pressure stage compressor main body 2 and the 1st cooling device 23 can be made comparatively short. The high-pressure stage compressor body 3 is disposed on the other side in the longitudinal direction of the compressor unit 21 in the gear casing 5. As a result, the connection piping (such as a discharge piping 26 described later) between the high-pressure compressor body 3 and the second cooling device 24 can be made relatively short.

  The first cooling device 23 is provided in a substantially vertical direction (vertical direction in FIGS. 8 to 10), connected to a first exhaust port 22 a provided on the upper surface of the soundproof cover 22, and the duct 27. Fan motors 29A and 29B respectively provided with cooling fans 28A and 28B that are provided above the inside (upper in FIGS. 8 to 10) and generate upward cooling air (shown by arrows in FIG. 10), and ducts Intercoolers 30A, 30B provided on the upstream side (lower side in FIG. 10) of the cooling fans 28A, 28B in the engine 27 and cooling the compressed air from the low-pressure stage compressor body 2 by exchanging heat with cooling air, An intake duct 31 connected to the lower side of the duct 27 and connected to a first intake port 22 b provided at the lower side of the soundproof cover 22 is provided.

  When the cooling fans 28A and 28B rotate as the fan motors 29A and 29B are driven, outside air from the first intake port 22b is introduced into the intake duct 31 as cooling air, and the cooling air in the duct 27 is directed upward. To the first exhaust port 22a through the intercoolers 30A and 30B and the cooling fans 28A and 28B. At this time, the intake duct 31 forms an intake passage 32 (intake space) between the first intake port 22b and the intercoolers 30A and 30B, and the cooling fans 28A and 28B in the duct 27 and the first exhaust air. An exhaust passage 33 (exhaust space) is formed between the opening 22a. Thereby, for example, when the intake flow path 32 and the exhaust flow path 33 are not formed (specifically, for example, when an intercooler is provided in contact with the first intake port 22b or when a cooling fan is provided in the first exhaust port 22a) As compared with the case of being provided in contact, noise leakage generated in the intercoolers 30A, 30B and the like can be reduced.

  The cooling fans 28A and 28B are arranged in parallel in the short width direction (left and right direction in FIG. 10) of the compressor unit 21, and the intercoolers 30A and 30B are compressed so as to be paired with the cooling fans 28A and 28B, respectively. The machine units 21 are arranged in parallel in the short width direction (in other words, the intercoolers 30A and 30B are arranged in parallel with the flow of the cooling air in the duct 27). The intercoolers 30A and 30B are respectively connected to the branch pipes 25a and 25b of the discharge pipe 25 connected to the discharge side of the low-pressure stage compressor body 2 and connected to the suction side of the high-pressure stage compressor body 3 The suction pipes 34 are connected to branch pipes 34a and 34b, respectively. The intercoolers 30 </ b> A and 30 </ b> B cool the compressed air from the low-pressure stage compressor body 2 by the cooling air passing through the fin portions 30 a and supply the cooled compressed air to the high-pressure stage compressor body 3. It has become. By providing the two systems of intercoolers 30A and 30B in this way, the intercooler 30A or 30B alone can be made small, for example, even if the size is limited by existing manufacturing equipment or the like, the manufacture thereof is easy. It can be. Further, by arranging the intercoolers 30A and 30B in parallel to the flow of the cooling air, for example, pressure loss can be reduced and the required power of the fan motors 29A and 29B can be reduced as compared with the case where they are arranged in series.

  Further, the intercoolers 30A and 30B are provided so as to be inclined with respect to the flow of the cooling air in the vertical direction in the duct 27 (specifically, upward toward the outside in the short width direction of the compressor unit 21). It is provided so as to be inclined and is arranged in a V-shape). Thereby, the width dimension of the 1st cooling device, ie, the width direction dimension W of a compressor unit, can be shortened. The intercoolers 30A and 30B may be provided so as to incline upward in the short width direction of the compressor unit 21 and to be parallel to each other.

  And in order to arrange | position efficiently, the jacket type oil cooler 35 is provided between the intercoolers 30A and 30B. The jacket-type oil cooler 35 cools the oil supplied from the oil reservoir in the gear casing 5 through the oil pipe 37a by heat exchange with the cooling air by the oil pump 36, and the cooled oil is sent through the oil pipe 37b. The liquid cooling jacket portion 1d of the low pressure stage compressor body 2 is supplied. The oil that has cooled the liquid cooling jacket portion 1d of the low-pressure stage compressor body 2 is introduced into the liquid cooling jacket portion 3d of the high-pressure stage compressor body 3 through the oil pipe 37c to be cooled, and then the gear through the oil pipe 37d. It returns to the oil sump in the casing 5.

  The second cooling device 24 has the same configuration as the first cooling device 23, is provided in a substantially vertical direction (vertical direction in FIGS. 8, 9, and 11), and is provided on the upper surface of the soundproof cover 22. A duct 38 connected to the second exhaust port 22c, and an upper portion of the duct 38 (upper in FIGS. 8, 9, and 11) and cooling air directed upward (illustrated by an arrow in FIG. 11). ) Are provided on the upstream side (lower side in FIG. 11) of the cooling fans 39A and 39B in the duct 38, respectively. The cooler 41 is connected to the lower side of the duct 38 and the second intake port 22d provided at the lower side of the side of the soundproof cover 22. And an intake duct 42 There.

  When the cooling fans 39A and 39B rotate as the fan motors 40A and 40B are driven, the outside air from the second intake port 22d is introduced into the intake duct 42 as cooling air, and the cooling air in the duct 38 is directed upward. It flows through the after-coolers 41A and 41B and the cooling fans 39A and 39B and is discharged from the second exhaust port 22c. At this time, the intake duct 42 forms an intake passage 43 (intake space) between the second intake port 22d and the aftercoolers 41A and 41B, and the cooling fans 39A and 39B and the second exhaust in the duct 38. An exhaust passage 44 (exhaust space) is formed between the opening 22c. Thereby, for example, when the intake flow path 43 and the exhaust flow path 44 are not formed (specifically, for example, when an aftercooler is provided in contact with the second intake port 22d, or when a cooling fan is provided in the second exhaust port 22c). As compared with the case of being provided in contact with each other, leakage of noise generated by the aftercoolers 41A, 41B and the like can be reduced.

  The cooling fans 39A and 39B are arranged in parallel in the short width direction (left and right direction in FIG. 11) of the compressor unit 21, and the aftercoolers 41A and 41B are compressed so as to be paired with the cooling fans 39A and 39B, respectively. The machine units 21 are arranged in parallel in the short width direction (in other words, the aftercoolers 41A and 41B are arranged in parallel to the flow of the cooling air in the duct 38). The aftercoolers 41A and 41B are connected to the branch pipes 26a and 26b of the discharge pipe 26 connected to the discharge side of the high-pressure stage compressor body 3 via check valves 45, respectively, and compressed air is supplied to the user side. Are connected to the branch pipes 46a and 46b of the supply pipe 46 for supplying. The aftercoolers 41A and 41B cool the compressed air from the high-pressure compressor main body 3 by the cooling air passing through the fin portions 41a, and supply the cooled compressed air to the user side. By providing the two systems of aftercoolers 41A and 41B in this way, the aftercooler 41A or 41B alone can be made small, for example, even if the size is limited by existing manufacturing equipment or the like, the manufacture thereof is easy. It can be. Further, by arranging the aftercoolers 41A and 41B in parallel with the flow of the cooling air, for example, pressure loss can be reduced and the required power of the fan motors 40A and 40B can be reduced as compared with the case where they are arranged in series.

  The aftercoolers 41A and 41B are provided so as to be inclined with respect to the flow of the cooling air in the vertical direction in the duct 38 (specifically, upward toward the outside in the short width direction of the compressor unit 21). It is provided so as to be inclined and is arranged in a V-shape). Thereby, the width dimension of the 2nd cooling device 24, ie, the width direction dimension W of the compressor unit 21, can be shortened. The aftercoolers 41A and 41B may be provided, for example, so as to incline upward in the short width direction of the compressor unit 21 and to be parallel to each other.

  And in order to arrange | position efficiently, the lubrication system oil cooler 47 is provided between the aftercoolers 41A and 41B. The lubrication system oil cooler 47 cools the oil supplied from the oil reservoir in the gear casing 5 through the oil pipe 48a by heat exchange with the cooling air by the oil pump 36, and the cooled oil is cooled by the oil pipe 48b, The bearings and timing gears of the low-pressure stage compressor body 2 and the high-pressure stage compressor body 3 are respectively supplied via 48c. And the oil which lubricated the bearing and the timing gear part of the low pressure stage compressor main body 2 and the high pressure stage compressor main body 3 returns to the oil sump in the gear casing 5 through the oil piping 48d.

  As described above, in the present embodiment, the entire unit can be reduced in size, and in particular, the effect can be greatly obtained in the large capacity compressor unit 21. Further, the size of the compressor unit 21 can be reduced, so that the transport means can be reduced in size.

2 Low pressure stage compressor body 2a Male rotor (rotor shaft)
3 High pressure stage compressor body 3a Male rotor (rotor shaft)
4 Motor 4a Rotating shaft 5 Gear casing 10 Bull gear (motor side gear)
12 Pinion gear (rotor side gear)
14 Pinion gear (rotor side gear)
16 Intermediate shaft 19 Pinion gear (first speed increasing gear)
20 Bull gear (second speed increasing gear)
21 Compressor unit 22a First exhaust port 22b First intake port 22c Second exhaust port 22d Second intake port 23 First cooling device 24 Second cooling device 27 Ducts 28A, 28B Cooling fans 30A, 30B Intercooler (heat exchanger for compressed air)
32 Intake channel (intake space)
33 Exhaust flow path (exhaust flow path)
35 Jacketed oil cooler (oil heat exchanger)
38 Duct 39A, 39B Cooling fan 41A, 41B After cooler (heat exchanger for compressed air)
43 Intake channel (intake space)
44 Exhaust flow path (exhaust space)
47 Lubricating oil cooler (heat exchanger for oil)

Claims (10)

A plurality of low pressure stage compressor bodies, a high pressure stage compressor body that further compresses compressed air compressed by the low pressure stage compressor body, and a plurality of rotor shafts provided on the low pressure stage compressor body and the high pressure stage compressor body, respectively. The rotor side gear, the motor, the motor side gear provided on the rotating shaft of the motor, the first gear for speed increasing and the plurality of rotor side gears that are rotatably supported and mesh with the motor side gear. An intermediate shaft provided with a second speed increasing gear; a gear casing that houses the motor side gear, the first speed increasing gear, the intermediate shaft, the second speed increasing gear, and the rotor side gear; A first cooling device that cools the compressed air from the low-pressure stage compressor body, and a second cooling device that cools the compressed air from the high-pressure stage compressor body,
The motor, the gear casing, the low-pressure stage compressor main body, and the high-pressure stage compressor main body are arranged in the center of the compressor unit, and the first cooling device is arranged on one side in the longitudinal width direction of the compressor unit. The screw compressor, wherein the second cooling device is arranged on the other side in the longitudinal width direction of the compressor unit.   2. The screw compressor according to claim 1, wherein a rotation shaft of the motor and a rotor shaft of the low-pressure compressor main body and the high-pressure compressor main body are parallel to each other and an axial direction thereof is directed in a short width direction of the compressor unit. The screw compressor is characterized in that the motor, the low-pressure stage compressor body, and the high-pressure stage compressor body are vertically arranged on one side in the axial direction.   3. The screw compressor according to claim 2, wherein the low-pressure stage compressor body is disposed on one side in a longitudinal width direction of the compressor unit in the gear casing, and the high-pressure stage compressor body is disposed in the gear casing. A screw compressor, which is disposed on the other side in the longitudinal width direction of the compressor unit.   The screw compressor according to any one of claims 1 to 3, wherein the first and second cooling devices include a duct provided in a substantially vertical direction and a cooling fan provided in the duct to generate cooling air. And a heat exchanger for compressed air that is arranged on the upstream side of the cooling fan in the duct and cools the compressed air from the low pressure stage compressor body or the high pressure stage compressor body by exchanging heat with cooling air, respectively. A screw compressor characterized by comprising.   5. The screw compressor according to claim 4, wherein the duct is connected to an intake port and an exhaust port of the compressor unit, and forms an intake space between the intake port and the heat exchanger for compressed air, A screw compressor characterized in that an exhaust space is formed between a cooling fan and the exhaust port.   5. The screw compressor according to claim 4, wherein either one or both of the first and second cooling devices are provided with a plurality of the heat exchangers for compressed air, A screw compressor characterized by being arranged in parallel with a flow of cooling air in a duct.   The screw compressor according to claim 6, wherein a plurality of the cooling fans are provided so as to be paired with the plurality of heat exchangers, and are arranged in parallel.   The screw compressor according to claim 6, wherein the plurality of heat exchangers for compressed air are arranged in parallel in a short width direction of the compressor unit.   The screw compressor according to claim 4, wherein the heat exchanger for compressed air is provided so as to be inclined with respect to a flow of cooling air in a vertical direction in the duct.   5. The screw compressor according to claim 4, wherein either one or both of the first and second cooling apparatuses are provided with a plurality of the heat exchangers for compressed air, A screw compressor characterized in that the oil compressor is provided between the plurality of compressed air heat exchangers so as to be inclined with respect to the flow of the cooling air in the vertical direction in the duct and arranged in parallel. .

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