JP5622649B2 - Screw compressor - Google Patents

Description

  The present invention relates to a screw compressor, and more particularly to a screw compressor having a strainer structure for cleaning various oils.

  As a conventional screw compressor, there is one described in Patent Document 1, for example. In this screw compressor, a cylindrical vertical centrifugal oil separator is formed on the back side or the front side of the compressor casing, and an oil reservoir space is integrally formed in the compressor casing at the bottom of the oil separator. The inside of the oil separator is an oil separation space, and an opening communicating with the oil sump space is formed in the lower part of the oil separation space. Oil is supplied by differential pressure through an oil supply passage formed so as to communicate with each bearing from an oil reservoir space.

  Moreover, in the screw compressor of patent document 2, oil is supplied with a differential pressure through an oil supply passage formed so as to communicate from the oil reservoir space to the cylinder chamber of the capacity control device.

  Moreover, in the screw compressor of patent document 3, the oil isolate | separated with the oil separator is stored in the oil sump space formed in the lower part in a casing. An oil flow path for supplying oil is communicated with the oil reservoir space. Oil flows into the oil passage through the built-in oil filter.

JP 2004-232669 A JP 2009-057842 A JP 2001-140780 A

  As a conventional example of an oil strainer used for a compressor or the like, an oil strainer described in Patent Document 3 (internal oil filter in Patent Document 3) is provided in an oil reservoir space described in Patent Document 1 or Patent Document 2. There is what formed. In the above prior art, since the oil level fluctuation in the oil reservoir space becomes extremely unstable due to the gas swirl flow in the oil separation space, the oil strainer cannot be completely immersed in the oil, and gas is mixed in the oil passing through the oil strainer. There is a fear. If this causes a shortage of oil supply and it becomes difficult to form an oil film on the bearing, it may cause a decrease in bearing life due to bearing wear and abnormal noise in the compressor, which may impair the reliability of the screw compressor. .

  An object of this invention is to provide a highly reliable screw compressor.

An object of the present invention is an oil strainer formed in a casing, configured to store lubricating oil, and a pipe member formed with a filtration portion and an oil outflow hole, and immersed in the lubricating oil in the oil storing space. A mounting hole formed in the casing, an oil outflow hole opened below the oil strainer, an oil supply passage formed above the mounting hole, and a sealed space formed by the pipe member and the mounting hole. The lubricating oil in the oil sump space flows out from the oil outflow hole opened below the oil strainer to the sealed space, and then flows into the oil supply passage formed above the sealed space via the sealed space. Achieved by a screw compressor .

  According to the present invention, a highly reliable screw compressor can be obtained.

It is a longitudinal cross-sectional view of the screw compressor which shows the Example of this invention. It is the sectional view on the AA line of FIG. It is sectional drawing which expands and shows the form of the oil strainer structure of FIG. It is sectional drawing which expands and shows the oil outflow hole part of an oil strainer.

  Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals in the drawings of the embodiments indicate the same or equivalent.

  First, the overall structure of the screw compressor of the present embodiment will be described with reference to FIGS.

  The compressor is composed of a motor compressor 1, a compressor section 2, a capacity control mechanism section 3, and a screw compressor provided with a supply / discharge oil passage. The motor unit 1 has a suction port 4, and a driving motor 7 is configured by the motor stator 5 and the motor rotor 6. The driving motor 7 is housed in a motor casing 8. The compressor unit 2 includes a main casing 9, a screw rotor 10, a roller bearing 11, a ball bearing 12, a discharge casing 13, and the like.

  The main casing 9 is formed with a cylindrical bore 9a and a suction port 9b for introducing gas into the cylindrical bore 9a. A pair of male and female screw rotors 10 (female rotor 10A not shown) rotatably supported by the roller bearing 11 and the ball bearing 12 are meshed with each other, and either one of the male or female rotor shafts is stored. A drive motor 7 housed in a motor casing 8 is directly connected. Further, the main casing 9 is integrally formed with an oil separator 14 and an oil reservoir space 15 on the back side or the front side thereof, and the oil separator 14 has an oil separation space 16 inside.

  A discharge port 17 that is a discharge passage from the screw rotor 10 is formed in the main casing 9, and the discharge passage is configured to communicate with the oil separation space 16. An opening 18 communicating with the oil sump space 15 is formed in the lower part of the oil separation space 16. An oil passage is formed in the main casing 9, and is configured to communicate with the oil sump space 15, each bearing, and the capacity control mechanism unit 3.

  The discharge casing 13 in which the roller bearing 11 and the ball bearing 12 are housed is fixed to the main casing 9 by means such as a bolt 19. The capacity control mechanism 3 includes a slide valve 20, a rod 21, a hydraulic piston 22 and a coil spring 23. The rod 21, the hydraulic piston 22 and the coil spring 23 are accommodated in the discharge casing 13. The slide valve 20 is for bypassing a part of the suction refrigerant gas sucked into the meshing portion of the screw rotor 10 to the suction side to control the capacity, and is slidably accommodated in the recess 24 extending in the lateral direction. Yes. The hydraulic piston 22 drives the slide valve 20 left and right via the rod 21 and is slidably accommodated in a cylinder chamber 25 extending in the lateral direction. The coil spring 23 is disposed on the slide valve 20 chamber side of the cylinder chamber 25 and applies a force that always presses the hydraulic piston 22 toward the anti-slide valve 20 side.

  Next, the flow of refrigerant gas and oil will be described. The low-temperature and low-pressure refrigerant gas sucked from the suction port 4 provided in the motor casing 8 is a gas passage formed between the driving motor 7 and the motor casing 8 and an air gap 26 between the motor stator 5 and the motor rotor 6. After cooling the drive motor 7, the suction port 9b formed in the main casing 9 is sucked into the compressor chamber formed by the meshing tooth surfaces of the male and female screw rotors 10 and the cylindrical bore 9a. . As the male rotor directly connected to the drive motor 7 rotates, the refrigerant gas is introduced into the compressor chamber and is gradually compressed as the compressor chamber is reduced to become a high-temperature and high-pressure gas. The oil is discharged to the discharge port 17 provided in the oil passage, passes through the discharge passage, and is discharged to the oil separation space 16 of the oil separator 14.

  Of the compression reaction force acting on the male and female screw rotors 10 during compression, the radial load is supported by the roller bearing 11, and the thrust load is supported by the ball bearing 12. The oil 27 for lubricating and cooling the bearings is supplied by differential pressure through an oil passage formed so as to communicate with each bearing portion from a high-pressure oil reservoir space 15 formed in the lower portion of the main casing 9. The supplied oil is discharged into the oil separation space 16 together with the compressed gas.

  The oil passage is also formed so as to communicate with the cylinder chamber 25 of the capacity control mechanism 3. A solenoid valve 28 is provided in the middle of the oil passage. The electromagnetic valve 28 controls the flow of oil to the cylinder chamber 25 by opening and closing thereof, and moves the hydraulic piston 22 in the left-right direction in FIG. Thereby, the position of the slide valve 20 is controlled, and the capacity control is performed.

  Next, an embodiment of the structure provided with the oil strainer 29 will be described with reference to FIGS.

  On the back side or the front side of the lower part of the main casing 9, a passage forming thick portion 31 that connects the oil reservoir space 15 and the oil supply passage 30 is formed. An oil strainer 29 is provided in the thick reservoir portion 31 in the oil reservoir space 15. A mounting hole 32 that is detachable from the outside is provided, and the mounting hole 32 is formed to communicate with the oil sump space 15. The oil strainer 29 is immersed in the oil 27 in the oil reservoir space 15, and the oil 27 that has passed through the oil strainer 29 is cleaned. The oil 27 is discharged from an oil outflow hole 33 formed in the oil strainer 29 and flows into the sealed space 36 formed by the mounting hole 32, the pipe member 34 of the oil strainer 29, and the two cylindrical plate members 35. The oil flows into an oil supply passage 30 provided above 32 and is supplied to each bearing portion and the capacity control mechanism portion 3.

  The oil strainer 29 has a structure in which a filtering portion 37 and an oil outflow hole 33 are divided into two pipe members 35 in one pipe member 34. The two cylindrical plate members 35 are joined to the pipe member 34 of the oil strainer 29 by means such as welding. A sealed space 36 composed of the mounting hole 32, the pipe member 34 of the oil strainer 29, and the two cylindrical plate members 35 is sealed with the oil reservoir space 15 by an O-ring 38, and is in one direction of the mounting hole 32 (left side in FIG. 2). Is sealed by a closing flange 39 and a gasket 40.

  The closing flange 39 is attached so as to be detachable by closing the opening in one direction (left side in FIG. 2) of the attachment hole 32 formed in the main casing 9 by means such as a bolt 41. Is configured to be pressed in the other direction (the right side in FIG. 2) by the closing flange 39, and is thus sealed from the oil sump space 15 by the O-ring 38. Further, a notch 42 is provided in the cylindrical plate member 35 at one end of the oil strainer 29 so that the oil outflow hole 33 of the oil strainer 29 is always opened directly below, and a positioning pin 43 is provided on the closing flange 39.

  The compressed refrigerant gas inlet of the oil separator 14 having an open discharge passage is opened in a direction substantially tangential to the inner wall of the oil separation space 16 so that the mixture of compressed refrigerant gas and oil follows the inner wall of the oil separator. It flows into a swirl flow along the cylindrical inner wall, and the oil is separated from the gas by centrifugal action. The separated oil falls along the wall surface, and is stored in the oil reservoir space 15 through the opening 18 that connects the oil separation space 16 and the oil reservoir space 15 in the compressor. The compressed refrigerant gas after oil separation is discharged from the discharge port 44 to the outside of the compressor.

  In this embodiment, the oil strainer 29 is divided into one pipe member 34, and the filtering portion 37 and the oil outflow hole 33 are divided by two cylindrical plate members 35, and the oil outflow hole 33 opens directly below the pipe member 34. It was. Therefore, even when the oil level fluctuation in the oil reservoir space becomes extremely unstable due to the gas swirling flow in the oil separation space of the oil separator 14 and the oil strainer cannot be completely immersed in the lubricating oil, the oil outlet hole 33 is formed. Since the fluid that passes through is only oil, oil can be reliably supplied to the oil supply passage 30 formed in the main casing 9. It is also effective when the amount of oil retained in the oil sump space decreases, especially when the oil strainer cannot be completely immersed in the oil.

  Furthermore, according to the present embodiment, the oil that has passed through the oil outflow hole 33 bypasses the sealed space 36 formed by the mounting hole 32, the pipe member 34 of the oil strainer 29, and the two cylindrical plate members 35, and the mounting hole 32. Since the oil flows into the oil supply passage 30 formed above the oil reservoir space 15, the oil is introduced into the sealed space 36 separated from the oil reservoir space 15, so that even when the oil level fluctuation in the oil reservoir space is significant, Variations can be reduced. This makes it less susceptible to oil level fluctuations in the oil reservoir space 15 and enables stable oil supply to the oil supply passage 30 formed in the main casing 9.

  As can be seen from FIG. 2, oil is also supplied from the oil supply passage 30 to the capacity control mechanism. If the oil to the cylinder chamber 25 is also mixed with gas, there is a possibility that the amount of oil supply will be insufficient. If this happens, the hydraulic control of the capacity control valve will be hindered and the movement speed of the capacity control valve will be delayed, that is, the response will be poor. There is a risk of doing. However, this can be avoided by the above.

  As described above, according to the oil strainer of the present embodiment, it is possible to suppress the inflow of the mixed fluid of oil and gas into the oil supply passage even in a situation where the oil level fluctuation in the oil sump space is extremely unstable, and reliably Since only the oil is supplied, it is possible to remove the causes of bearing life reduction and compressor abnormal noise due to bearing wear, and to improve the reliability of the compressor. In addition, the hydraulic control performance of the capacity control valve can be enhanced.

DESCRIPTION OF SYMBOLS 1 Motor part 2 Compressor part 3 Capacity | capacitance control mechanism part 4 Inlet 5 Motor stator 6 Motor rotor 7 Drive motor 8 Motor casing 9 Main casing 10 Screw rotor 11 Roller bearing 12 Ball bearing 13 Discharge casing 14 Oil separator 15 Oil reservoir space 16 Oil separation space 17 Discharge port 18 Opening 19 Bolt 20 Slide valve

Claims (3)

  An oil sump space formed in the casing for storing lubricating oil;
  An oil strainer formed by forming a filtration part and an oil outflow hole in the pipe member, and immersed in the lubricating oil in the oil reservoir space;
  Mounting holes formed in the casing;
  The oil outflow hole opened below the oil strainer;
  An oil supply passage formed above the mounting hole;
  A sealed space formed by the pipe member and the mounting hole;
With
  Lubricating oil in the oil reservoir space flows out from the oil outlet hole opened below the oil strainer to the sealed space, and then formed above the sealed space via the sealed space. A screw compressor that flows into the oil supply passage.   2. The screw compressor according to claim 1, wherein the filtering part and the oil outflow hole are divided by two cylindrical plate members.   The screw compressor according to claim 2, wherein the cylindrical plate member is a member for fixing to the mounting hole.

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