JP2014211101A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain an inexpensive screw compressor having high performance and high oil separating efficiency, capable of suppressing the movement in a swirling direction of an upward flow moving inside an inner cylinder part while maintaining the flow velocity of a swirl flow moving outside the inner cylinder part without performing welding work for a swirl intensifying plate and a straightening plate requiring much time and effort when manufactured.SOLUTION: The surface roughness of the outer peripheral face of an inner cylinder part 14 of a cyclone oil separator 4 is different from that of the inner peripheral face thereof. The outer peripheral face has reduced surface roughness to reduce the resistance of the swirl flow, and the inner peripheral face has increased surface roughness to increase the resistance of the swirl flow.

Description

  The present invention relates to the structure of an oil separator installed in a compressor.

  In a compressor, a large amount of oil is supplied to the bearing and the compression chamber for the purpose of lubricating the bearing, cooling the compression heat, and sealing the gap. The supplied oil is discharged from the compression chamber together with the compressed gas. Therefore, oil and gas must be separated by an oil separation mechanism and supplied to the bearing and the compression chamber again. In addition, if the oil discharged to the discharge section is discharged to the cycle side outside the compressor, it will adversely affect the heat exchange in the condenser and evaporator, leading to performance degradation, so before it is discharged to the cycle side In addition, it is necessary to separate and recover the gas with an oil separation mechanism.

  A compressor having an oil separator for separating oil and gas is known. As a method of separating oil and gas, there is a method called cyclone method that separates oil and gas by centrifugal force using a gas-liquid density difference, and its structure is formed by a double cylindrical part, and oil separation is performed. A centrifugal separation part for generating a centrifugal force to be performed, and a passage part that is separated from the oil by the centrifugal force and descends while swirling is swirled up to the inside of the inner cylinder part and discharged to the cycle side.

  In a compressor equipped with a cyclone oil separator, in order to efficiently separate oil and gas, it is necessary to maintain the swirl flow rate by suppressing the centrifugal force in the centrifugal separation part, that is, the decrease in swirl flow rate In order to improve the compressor performance, the flow rate in the swirling direction of the upward flow in the passage portion is suppressed, and the swirling upward flow after separating the oil passes through the outlet portion and the outlet portion where the opening area is reduced. In this case, it is necessary to reduce the pressure loss that occurs when passing through the check valve portion thereafter.

  Therefore, a plate-shaped swirl flow reinforcing plate is provided from the outer periphery of the inner cylinder portion toward the inner wall of the outer cylinder to maintain the swirl flow velocity, and the oil is efficiently separated while suppressing the decrease in swirl flow velocity. The space is vertically divided by a baffle plate in the circumferential direction to make resistance to the swirling upward flow after oil separation, and by reducing the flow velocity in the swirling direction, pressure loss is reduced, and the oil separation efficiency and refrigeration cycle performance are increased. A compressor equipped with an oil separator is known. (For example, refer to Patent Document 1).

Japanese Patent Laying-Open No. 2003-83272 (FIG. 1)

  However, in a compressor equipped with a conventional oil separator, work such as welding is required to provide a swirl flow reinforcing plate that maintains the swirl flow velocity in the centrifugal separation part and a rectifying plate that suppresses the speed of swirl upflow in the passage part. For this reason, there is a problem that manufacturability such as assembling of parts is poor and time and cost are required for manufacturing.

  The present invention has been made to solve the above-described problems, and maintains the swirling flow velocity in the centrifugal separation portion without generating work such as welding for providing a swirl flow reinforcing plate or a rectifying plate. An object of the present invention is to provide a compressor that suppresses the speed of the swirl upward flow in the passage portion, and realizes an improvement in compressor performance by high efficiency oil separation efficiency and pressure loss reduction with an inexpensive and easy structure.

  The compressor according to the present invention has different surface roughness between the outer peripheral surface of the inner cylinder portion and the inner peripheral surface of the cyclone oil separator, and the outer peripheral surface reduces the surface roughness to reduce the resistance of the swirling flow. The peripheral surface is characterized by increasing the surface roughness and increasing the resistance of the swirling flow.

  According to the present invention, by reducing the surface roughness of the outer peripheral surface of the inner cylindrical portion of the oil separator and reducing the resistance to the swirling flow, the swirling flow velocity for performing the centrifugal separation is maintained, and the swirling flow velocity is reduced. In addition to suppressing the flow velocity in the swirling direction in the upward flow after oil separation by increasing the surface roughness of the inner circumferential surface of the inner cylinder of the oil separator and increasing the resistance to the swirling flow Since the pressure loss due to the upward flow can be reduced, it is possible to provide a compressor capable of realizing high-efficiency oil separation efficiency and improved compressor performance by reducing pressure loss with an easy structure and low cost.

It is a cross-sectional view of the screw compressor which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the oil separator which concerns on Embodiment 1 of this invention. It is a cross-sectional view of the oil separator which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the oil separator which concerns on Embodiment 2 of this invention. It is a cross-sectional view of the oil separator according to Embodiment 2 of the present invention. It is a longitudinal cross-sectional view of the oil separator which concerns on Embodiment 3 of this invention. It is a cross-sectional view of the oil separator which concerns on Embodiment 3 of this invention. It is a longitudinal cross-sectional view of the oil separator which concerns on Embodiment 4 of this invention. It is a cross-sectional view of the oil separator according to Embodiment 4 of the present invention.

Hereinafter, a preferred embodiment of a compressor according to the present invention will be described with reference to the drawings. Note that the present invention is not limited by these embodiments.

Embodiment 1 FIG.
The screw compressor according to the first embodiment will be described with reference to FIGS.
FIG. 1 is a schematic sectional view of a screw compressor according to Embodiment 1 of the present invention. More specifically, the right side (A side) of the two-dot chain line indicates the screw compressor according to Embodiment 1 in the horizontal direction. It is the cut cross-sectional schematic, and the left side (B side) from the dashed-two dotted line is the longitudinal cross-sectional schematic which cut | disconnected the screw compressor which concerns on this Embodiment 1 in the orthogonal | vertical direction.

FIG. 2 is an enlarged view of the cross section of the oil separator in the cross-sectional schematic diagram shown in FIG. 1 of the screw compressor according to the first embodiment, and FIG. 3 is a screw compression according to the first embodiment. It is the figure which showed the mode of the cross section at the time of cut | disconnecting the oil separator of a machine in the horizontal direction and seeing from the lower surface.

  The screw compressor 1 according to Embodiment 1 is a single screw compressor provided with an oil separator, and an oil separator fastened to a compressor main body 2 and a casing 3 constituting the compressor main body 2 by bolts. And a container 4.

As shown in FIG. 1, the compressor main body 2 includes a cylindrical casing 3, a motor 5 accommodated in the casing 3, a screw shaft 6 fixed to the motor 5 and driven to rotate by the motor 5, a screw A screw rotor 7 fixed to the shaft 6 and a bearing 8 that rotatably supports an end portion of the screw shaft 6 that is not fixed to the motor 5 are provided.

Further, the side surface of the screw rotor 7 is provided with a pair of gate rotors 9 arranged so as to be axial objects with respect to the screw shaft 6, and is slidably provided between the side surface of the casing 3 and the screw rotor 7. The slide valve 10 is provided.

The motor 5 includes a stator 5a that is inscribed and fixed in the casing 3, and a motor rotor 5b that is disposed inside the stator 5a. The motor rotor 5b is fixed to the screw shaft 6, and the screw rotor 7 and It is arranged on the same line.

The screw rotor 7 has a cylindrical shape, and a plurality of screw grooves 7 a extending in a spiral shape from one end of the screw rotor 7 to the other end are formed on the outer peripheral surface. The casing 3 is separated from the suction pressure side filled with the low-pressure refrigerant gas and the discharge pressure side filled with the high-pressure refrigerant gas, and one end side of the screw rotor 7 becomes the refrigerant gas suction side and communicates with the suction pressure side. The other end of the rotor 7 becomes the refrigerant gas discharge side, and the screw groove 7a communicates with the discharge pressure side.

The gate rotor 9 has a disk shape, and a plurality of tooth portions 9a are provided on the outer peripheral surface along the circumferential direction. The tooth portion 9a of the gate rotor 9 is disposed so as to mesh with the screw groove 7a of the screw rotor 7, and is surrounded by the screw groove 7a, the tooth portion 9a of the gate rotor 9, the inner peripheral surface of the casing 3, and the slide valve 10. The space is formed as a compression chamber 11 filled with a refrigerant gas to be compressed. Oil for lubricating the bearing 8 and sealing the compression chamber 11 is injected into the compression chamber 11.

The slide valve 10 is slidably provided on the suction pressure side and the discharge pressure side of the screw rotor 7 along the outer peripheral surface of the screw rotor 7, and has an opening 10a at the center.

Further, a discharge port (not shown) connected to the discharge chamber 12 is opened on the inner peripheral surface on the discharge pressure side of the casing 3, and the high-pressure refrigerant gas and oil filled in the compression chamber 11 are transferred to the slide valve 10. Is discharged into the discharge chamber 12 through the opening 10a and the discharge port.

The discharge chamber 12 is a space in which the high-pressure refrigerant gas and oil in the compression chamber 11 are discharged, and guides the high-pressure refrigerant gas and oil filled in the discharge chamber 12 to the oil separator 4.

  Next, the oil separator 4 will be described in detail with reference to FIGS. The oil separator 4 is a cyclone type oil separator for separating refrigerant gas and oil, and is fastened to the casing 3 of the compressor main body 2 by bolts as shown in FIG.

The oil separator 4 is formed of a double cylinder and covers the outer cylinder part 13, the inner cylinder part 14 provided inside the outer cylinder part 13, and the upper opening part of the outer cylinder part 13 and the inner cylinder part 14. The lid portion 15, a bottom portion 16 that covers the bottom of the outer cylinder portion 13, and a wave plate 17 provided below the outer cylinder portion 13.

The outer cylinder part 13 is fastened to the compressor body part 2 by bolts, and an inlet (not shown) communicating with the discharge chamber 12 of the compressor body part 2 is provided above the inner surface of the outer cylinder part 13. The inner peripheral surface of the outer cylinder portion 13 is machined so that the surface roughness is reduced.

Moreover, the inner cylinder part 14 and the cover part 15 are integrated, and the cover part 15 is fastened by the outer cylinder part 13 with the volt | bolt. The inner cylinder part 14 is processed so that the surface roughness of the outer peripheral surface is different from that of the inner peripheral surface, the outer peripheral surface is cut to reduce the surface roughness, and the inner peripheral surface is a groove that increases the surface roughness. Processing has been applied.

The lid portion 15 has a disk shape, and as shown in FIG. 3, a hole penetrating in the vertical direction and having a diameter smaller than the inner diameter of the inner cylinder portion 14 is provided in the center. This hole is an outlet portion 15a for discharging the refrigerant gas after oil is separated in the oil separator 4 from the screw compressor 1, and a check valve 18 is provided downstream of the outlet portion 15a.

The wave plate 17 extends in parallel with the opening surface of the inner cylinder portion 14 and is a plate that folds down the refrigerant gas descending inside the outer cylinder portion 13 and suppresses disturbance of the oil surface. is there. Furthermore, an oil storage part 19 in which oil separated from the refrigerant gas is stored is formed at the lowermost end inside the outer cylinder part 13.

Next, the flow of refrigerant gas and oil in the screw compressor according to the first embodiment will be described.

  When the motor 5 fixed on the same axis as the screw rotor 7 rotates, the low-pressure refrigerant gas sucked from the suction pressure side of the screw rotor 7 is compressed in the compression chamber 11 and discharged from the screw rotor 7. Sent to the side. The refrigerant gas compressed to a high pressure is discharged from the discharge port to the discharge chamber 12 together with the oil injected into the compression chamber 11, and is led out from the discharge chamber 12 to the oil separator 4.

Refrigerant gas and oil that have reached the oil separator 4 flow in from an inlet opening in the side surface of the outer cylinder part 13 and descend while swirling through the gap between the outer cylinder part 13 and the inner cylinder part 14. At this time, of the refrigerant gas and oil that swirls and descends, oil having a density higher than that of the refrigerant gas is blown to the inner peripheral surface of the outer cylinder portion 13 by centrifugal force, and the oil and the refrigerant gas are separated.

Moreover, since the surface roughness of the inner peripheral surface of the outer cylindrical portion 13 and the outer peripheral surface of the inner cylindrical portion 14 is reduced by machining, a decrease in the flow rate due to the frictional resistance of the swirling flow is suppressed, and the speed of the swirling flow is maintained. Thus, it is possible to prevent the oil separation efficiency from being deteriorated due to a decrease in centrifugal force and to improve the oil separation efficiency.

Further, the oil separated by the swirling flow falls to the oil reservoir 19 due to gravity, and the oil stored in the oil reservoir 19 passes through a path (not shown) provided in the casing 3 and is a compression chamber. 11 and the bearing 8.

On the other hand, the refrigerant gas separated from the oil descends while turning, turns back at the wave plate 17, and flows upward into the inner cylinder portion 14 while continuing the turning. Then, after passing through the inside of the inner cylinder portion 14, it passes through the check valve 18 from the outlet portion 15 a of the lid portion 15 and flows out to the cycle side.

At this time, since the inner peripheral surface of the inner cylinder portion 14 has a large surface roughness by machining, the flow velocity in the swirling direction is suppressed by resisting the flow in the swirling direction, and the oil caused by the rising swirling flow is reduced. The pressure loss at the check valve 18 can be reduced and the compressor performance can be improved.

  As described above, according to the first embodiment, by reducing the surface roughness of the inner peripheral surface of the outer cylindrical portion and the outer peripheral surface of the inner cylindrical portion, and increasing the surface roughness of the inner peripheral surface of the inner cylindrical portion, It is possible to maintain the flow velocity of the swirling flow generated between the outer tube portion and the inner tube portion and to suppress the swirl direction flow flowing inside the inner tube portion.

That is, since the flow velocity of the swirling flow flowing outside the inner cylinder portion can be maintained and the flow in the swirling direction flowing inside the inner cylinder portion can be suppressed without providing the swirl strengthening plate and the rectifying plate. Therefore, it is possible to reduce the manufacturing time and cost, and to easily obtain an inexpensive high-performance and high oil separation efficiency screw compressor.

Embodiment 2
A screw compressor according to the second embodiment will be described with reference to FIGS.
FIG. 4 is an enlarged view of a cross section of the cyclone oil separator in the screw compressor according to the second embodiment, and FIG. 5 shows the oil separator of the screw compressor according to the second embodiment in the lateral direction. It is the figure which showed the mode of the cross section at the time of cut | disconnecting and seeing from the lower surface. The overall cross-sectional structure of the screw compressor according to the second embodiment is substantially the same as FIG. 1 shown in the first embodiment except that the inner cylinder portion and the lid portion are replaced with the cylindrical lid portion. As shown, only the enlarged view of the oil separator is shown and described.

The second embodiment is different from the first embodiment shown in FIG. 2 in that the lid portion and the inner cylinder portion are integrally formed by casting and the boundary surface is formed into a curved surface. Other configurations are the same as or equivalent to those of the first embodiment. In addition, the same code | symbol is attached | subjected about the component which is the same as that of Embodiment 1, or equivalent, and the description is abbreviate | omitted.

As shown in FIG. 4, the oil separator 20 includes an outer cylinder part 21, a cylindrical lid part 22 that covers the upper part of the outer cylinder part 21, a bottom part 16 that covers the bottom of the outer cylinder part 21, and an outer cylinder part 21. It is comprised with the wave plate 17 provided in the internal downward direction.

The cylindrical lid part 22 is integrally formed with a lid part 22a and an inner cylinder part 22b by casting, and is fastened to the outer cylinder part 21 by bolts. The outer peripheral surface of the inner cylindrical portion 22b is machined so as to reduce the surface roughness, but the inner peripheral surface of the inner cylindrical portion 22b is not processed and has a shape that leaves a cast surface. It has become. Furthermore, the outer cylinder part 21 is also formed by casting, and the inner peripheral surface of the outer cylinder part 21 is machined so that the surface roughness becomes small.

As shown in FIG. 5, an outlet portion 22c that penetrates vertically and has a diameter smaller than the inner diameter of the inner cylindrical portion 22b is provided in the center of the lid portion 22a, and the boundary between the lid portion 22a and the inner cylindrical portion 22b is A smooth R-shaped curved surface is formed from the inner peripheral surface of the inner cylindrical portion 22b to the edge of the outlet portion 22c of the lid portion 22a. Since the lid portion 22a and the inner cylinder portion 22b are formed by casting, a curved plate is used to form a curved surface from the upper part of the inner peripheral surface of the inner cylinder portion 22b to the outlet portion 22c of the lid portion 22a. There is no need for troublesome work such as welding or processing to form a curved surface, and it can be easily formed by previously forming a casting mold.

Next, the flow of refrigerant gas and oil in the screw compressor according to the second embodiment will be described.

  When the motor 5 fixed on the same axis as the screw rotor 7 rotates, the low-pressure refrigerant gas sucked from the suction pressure side of the screw rotor 7 is compressed in the compression chamber 11 and discharged from the screw rotor 7. Sent to the side. The refrigerant gas compressed to a high pressure is discharged from the discharge port to the discharge chamber 12 together with the oil injected into the compression chamber 11, and is led out from the discharge chamber 12 to the oil separator 20.

Refrigerant gas and oil that have reached the oil separator 20 flow in from the inlet opening in the side surface of the outer cylinder part 21, and descend while swirling through the gap between the outer cylinder part 21 and the inner cylinder part 22b. At this time, of the refrigerant gas and oil swirling and descending, oil having a density higher than that of the refrigerant gas is blown to the inner peripheral surface of the outer cylinder portion 21 by centrifugal force, and the oil and the refrigerant gas are separated.

Further, since the surface roughness of the inner peripheral surface of the outer cylindrical portion 21 and the outer peripheral surface of the inner cylindrical portion 22b is reduced by machining, a decrease in flow velocity due to the frictional resistance of the swirling flow is suppressed, and the speed of the swirling flow is maintained. Thus, it is possible to prevent the oil separation efficiency from being deteriorated due to a decrease in centrifugal force and to improve the oil separation efficiency.

Further, the oil separated by the swirling flow falls to the oil reservoir 19 due to gravity, and the oil stored in the oil reservoir 19 passes through a path (not shown) provided in the casing 3 and is a compression chamber. 11 and the bearing 8.

On the other hand, the refrigerant gas separated from the oil descends while turning, turns back at the wave plate 17, and flows upward into the inner cylinder portion 22 b while continuing the turning. Then, it passes through the inner cylinder portion 22b, passes through the check valve 18 from the outlet portion 22c of the lid portion 22a, and flows out to the cycle side.

At that time, the inner peripheral surface of the inner cylindrical portion 22b is left as it is, so that the surface roughness is large, and the swirling flow is suppressed by resisting the flow in the swirling direction. And the pressure loss at the outlet portion 22c of the lid portion 22a and the check valve 18 can be reduced, and the performance of the compressor can be improved.

In addition, since a smooth curved surface is formed from the inner peripheral surface of the inner cylindrical portion 22b to the edge of the outlet portion 22c of the lid portion 22a, the occurrence of pressure loss due to contraction due to a sudden change in the opening area is suppressed. The upward flow that has flowed into the inner cylindrical portion 22b can flow out of the oil separator 20 without resistance, and the pressure loss due to the rapid contraction of the flow path can be further suppressed.

  As described above, according to the second embodiment, by integrally forming the lid portion and the inner cylindrical portion by casting, the surface roughness of the inner peripheral surface of the inner cylindrical portion can be increased without processing, and welding or the like can be performed. The boundary between the lid portion and the inner cylinder portion can be finished into a curved surface without performing the above operation. Therefore, since it is possible to save the process of increasing the surface roughness of the inner peripheral surface of the inner cylinder part and the troublesome work of welding and forming a curved plate at the boundary between the lid part and the inner cylinder part, It is possible to reduce the number of manufacturing steps, and it is possible to obtain a high-performance, high oil separation efficiency screw compressor having a structure that is more easily and cheaper than that of the first embodiment and that is excellent in productivity.

Embodiment 3
A screw compressor according to the third embodiment will be described with reference to FIGS.
FIG. 6 is an enlarged view of a cross section of the oil separator in the screw compressor according to Embodiment 3 of the present invention, and FIG. 7 shows the oil separator of the screw compressor according to Embodiment 3. It is the figure which showed the mode of the cross section at the time of cut | disconnecting to a horizontal direction and seeing from the lower surface. The cross-sectional structure of the entire screw compressor according to the third embodiment is substantially the same as that of FIG. 1 shown in the first embodiment except that the inner cylinder portion and the lid portion are replaced with the cylindrical lid portion and the presence or absence of the current plate. Therefore, only an enlarged view of the oil separator is shown and described as shown in FIG.

The third embodiment is different from the second embodiment shown in FIG. 4 in that a rectifying plate is provided inside the inner cylinder portion. Other configurations are the same as or equivalent to those of the second embodiment. In addition, the same code | symbol is attached | subjected about the component which is the same as that of Embodiment 2, or equivalent, and the description is abbreviate | omitted.

As shown in FIG. 6, the oil separator 30 includes an outer cylinder part 21, a cylindrical lid part 31 that covers the upper part of the outer cylinder part 21, a bottom part 16 that covers the bottom of the outer cylinder part 21, and an outer cylinder part 21. It is comprised with the wave plate 17 provided in the internal downward direction.

In the cylindrical lid portion 31, a lid portion 31a and an inner cylinder portion 31b are integrally formed by casting, and as shown in FIG. 7, the center of the lid portion 31a penetrates vertically and is smaller than the inner diameter of the inner cylinder portion 31b. An outlet portion 31c having a diameter is provided, and a smooth R-shaped curved surface is formed at the boundary between the lid portion 31a and the inner cylinder portion 31b from the inner peripheral surface of the inner cylinder portion 31b to the edge of the outlet portion 31c of the lid portion 31a. ing.

A rectifying plate 31d formed integrally with the inner cylinder portion 31b by casting is provided below the inner cylinder portion 31b so as to divide the opening cross section of the space inside the inner cylinder portion 31b. The inner peripheral surface of the inner cylinder portion 31b is not processed and has a shape that leaves a cast surface.

In addition, since the current plate 31d is integrally formed with the lid portions 31a and 31b by casting, work such as welding does not occur, no troublesome work is required, and it is easy to form in a casting mold in advance. Can be formed.

Next, the process of refrigerant gas and oil flow in the screw compressor according to the third embodiment will be described.

  When the motor 5 fixed on the same axis as the screw rotor 7 rotates, the low-pressure refrigerant gas sucked from the suction pressure side of the screw rotor 7 is compressed in the compression chamber 11 and discharged from the screw rotor 7. Sent to the side. The refrigerant gas compressed to a high pressure is discharged from the discharge port to the discharge chamber 12 together with the oil injected into the compression chamber 11, and is led out from the discharge chamber 12 to the oil separator 30.

Refrigerant gas and oil that have reached the oil separator 30 flow from the inlet opening in the side surface of the outer cylinder part 21, and descend while swirling through the gap between the outer cylinder part 21 and the inner cylinder part 31b. At this time, of the refrigerant gas and oil swirling and descending, oil having a density higher than that of the refrigerant gas is blown to the inner peripheral surface of the outer cylinder portion 21 by centrifugal force, and the oil and the refrigerant gas are separated.

In addition, since the surface roughness of the inner peripheral surface of the outer cylindrical portion 21 and the outer peripheral surface of the inner cylindrical portion 31b is reduced by machining, a decrease in the flow velocity due to the frictional resistance of the swirling flow is suppressed, and the speed of the swirling flow is maintained. Thus, it is possible to prevent the oil separation efficiency from being deteriorated due to a decrease in centrifugal force and to improve the oil separation efficiency.

Further, the oil separated by the swirling flow falls to the oil reservoir 19 due to gravity, and the oil stored in the oil reservoir 19 passes through a path (not shown) provided in the casing 3 and is a compression chamber. 11 and the bearing 8.

On the other hand, the refrigerant gas separated from the oil descends while turning, turns back at the wave plate 17, and flows upward into the inner cylinder portion 31 b while continuing the turning. Then, it passes through the inner cylinder portion 31b, passes through the check valve 18 from the outlet portion 31c of the oil separator 30, and flows out to the cycle side.

At that time, since the rectifying plate 31d is provided inside the inner cylinder portion 31b, the swirling of the upward flow is suppressed, and the cast surface is left as it is on the inner peripheral surface of the inner cylinder portion 31b. Therefore, the surface roughness is high, and the swirling flow is further suppressed by the flow resistance in the swirling direction, the oil entrainment due to the rising swirling flow is suppressed, and the pressure loss at the outlet portion 31c of the lid portion 31a and the check valve 18 The compressor performance can be improved.

In addition, since a smooth curved surface is formed from the inner peripheral surface of the inner cylinder portion 31b to the edge of the outlet portion 31c of the lid portion 31a, the occurrence of pressure loss due to contraction due to a sudden change in the opening area is suppressed. The upward flow that has flowed into the inner cylinder portion 31b can be allowed to flow out of the oil separator 30 without resistance, and the pressure loss due to the rapid contraction of the flow path can be further suppressed.

  As described above, according to the third embodiment, the lid part and the inner cylinder part are integrally formed by casting, and further, the rectifying plate is integrally formed inside the inner cylinder part by casting, so that the lid part and the inner cylinder part are formed. Since the rectifying plate can be manufactured together with the process of integrally forming by casting, the rectifying plate can be created inside the inner cylinder part without performing welding work inside the inner cylinder part, which is troublesome to manufacture. . That is, since the current plate can be provided with the same number of manufacturing steps as in the second embodiment, a screw compressor with higher performance and higher separation efficiency can be obtained while maintaining excellent productivity.

Embodiment 4
A screw compressor according to the fourth embodiment will be described with reference to FIGS.
FIG. 8 is an enlarged view of a cross section of the oil separator in the screw compressor according to Embodiment 4 of the present invention, and FIG. 9 shows the oil separator of the screw compressor according to Embodiment 4. It is the figure which showed the mode of the cross section at the time of cut | disconnecting to a horizontal direction and seeing from the lower surface. The cross-sectional structure of the entire screw compressor according to the fourth embodiment is substantially the same as FIG. 1 shown in the first embodiment except that the inner cylinder portion and the lid portion are replaced with the cylindrical lid portion and the presence or absence of the rectifying plate. Therefore, as shown in FIG. 8, only an enlarged view of the oil separator is described and described.

The fourth embodiment is different from the third embodiment shown in FIG. 6 in that the position where the rectifying plate is provided is not inside the inner cylinder part but inside the outer cylinder part, and between the inner cylinder part and the wave plate. It is a point provided in the space. Other configurations are the same as or equivalent to those of the fourth embodiment. In addition, the same code | symbol is attached | subjected about the component which is the same as that of Embodiment 3, or equivalent, and the description is abbreviate | omitted.

As shown in FIG. 8, the oil separator 40 includes an outer cylinder part 41, a cylindrical lid part 31 that covers the upper part of the outer cylinder part 41, a bottom part 16 that covers the bottom of the outer cylinder part 41, and an outer cylinder part 41. It is comprised with the wave plate 17 provided in the internal downward direction.

In the cylindrical lid portion 31, a lid portion 31a and an inner cylindrical portion 31b are integrally formed by casting. As shown in FIG. 9, the cylindrical lid portion 31 vertically penetrates the center of the lid portion 31a and is smaller than the inner diameter of the inner cylindrical portion 31b. An outlet portion 31c having a diameter is provided, and a smooth R-shaped curved surface is formed at the boundary between the lid portion 31a and the inner cylinder portion 31b from the inner peripheral surface of the inner cylinder portion 31b to the edge of the outlet portion 31c of the lid portion 31a. ing.

Further, by casting the outer cylinder part 41 and the outer cylinder part 41 so as to divide the opening cross section of the space inside the outer cylinder part 41 into a space part located between the inner cylinder part 31 b and the wave plate 17. An integrally formed rectifying plate 41d is provided. The position where the rectifying plate 41d is provided is provided at a distance that does not affect the centrifugal separation of the oil by the flow of the swirling flow that flows into the inner cylinder portion 31b. The upper surface of the plate 17 is provided below the middle position of the lower end surface of the inner cylinder portion 31b.

In addition, since the current plate 41d is integrally formed with the outer cylinder portion 41 by casting, work such as welding does not occur and troublesome work is not necessary, and it is easily formed by pre-molding into a casting mold. can do.

Next, the flow of refrigerant gas and oil in the screw compressor according to Embodiment 4 will be described.

  When the motor 5 fixed on the same axis as the screw rotor 7 rotates, the low-pressure refrigerant gas sucked from the suction pressure side of the screw rotor 7 is compressed in the compression chamber 11 and discharged from the screw rotor 7. Sent to the side. The refrigerant gas compressed to a high pressure is discharged from the discharge port to the discharge chamber 12 together with the oil injected into the compression chamber 11, and is led out from the discharge chamber 12 to the oil separator 40.

Refrigerant gas and oil that have reached the oil separator 40 flow from the inlet opening in the side surface of the outer cylinder portion 41, and descend while swirling through the gap between the outer cylinder portion 41 and the inner cylinder portion 31b. At this time, of the refrigerant gas and oil swirling and descending, oil having a density higher than that of the refrigerant gas is blown to the inner peripheral surface of the outer cylinder portion 41 by centrifugal force, and the oil and the refrigerant gas are separated.

Moreover, since the surface roughness of the inner peripheral surface of the outer cylindrical portion 41 and the outer peripheral surface of the inner cylindrical portion 31b is reduced by machining, a decrease in the flow velocity due to the frictional resistance of the swirling flow is suppressed, and the speed of the swirling flow is maintained. Thus, it is possible to prevent the oil separation efficiency from being deteriorated due to a decrease in centrifugal force and to improve the oil separation efficiency.

Further, the oil separated by the swirling flow falls to the oil reservoir 19 due to gravity, and the oil stored in the oil reservoir 19 passes through a path (not shown) provided in the casing 3 and is a compression chamber. 11 and the bearing 8.

On the other hand, the refrigerant gas separated from the oil descends while turning, but a rectifying plate 41d is provided between the inner cylinder portion 31b and the wave plate 17 so as to divide the cross section of the space inside the outer cylinder portion 41. Thus, the flow in the turning direction is suppressed by the rectifying plate 41d. Then, the wave is turned back by the wave plate 17 and is turned into an upward flow in a state where the turning is suppressed, and flows into the inner cylinder portion 31b. And it passes through the check valve 18 from the outlet 31c of the oil separator 40 and flows out to the cycle side via the inside of the inner cylinder part 31b.

At that time, since the rectifying plate 41d is provided between the inner cylindrical portion 31b inside the outer cylindrical portion 41 and the wave rectifying plate 17, the swirling of the upward flow is suppressed before flowing into the inner cylindrical portion 31b, and the rising swirl It is possible to improve the performance of the compressor by suppressing oil entrainment due to the flow and reducing pressure loss at the outlet 31c of the lid 31a and the check valve 18 more effectively.

  As described above, according to the fourth embodiment, since the current plate is integrally formed with the outer cylinder part by casting, the current plate can be manufactured together with the step of forming the outer cylinder part. The rectifying plate can be created inside the outer cylinder part without performing labor-intensive welding work inside the outer cylinder part. Therefore, as in the third embodiment, the baffle plate can be provided with the same number of manufacturing steps as in the second embodiment, so that a screw compressor with higher performance and higher separation efficiency while maintaining excellent productivity. Can be obtained.

Further, since the rectifying plate is provided not in the inner cylinder part but in a space located between the inner cylinder part inside the outer cylinder part and the wave plate, the swirl direction of the swirling flow descending before flowing into the inner cylinder part The flow in the swirling direction and the upward swirling flow can both be suppressed, so that the oil entrainment due to the rising swirling flow and the pressure loss at the outlet of the lid and the check valve are more effective. The performance of the compressor can be improved.

In the second, third, and fourth embodiments, a smooth R-shaped curved surface is formed at the boundary between the lid portion and the inner cylindrical portion from the inner peripheral surface of the inner cylindrical portion toward the edge of the outlet portion of the lid portion. However, the shape of the boundary between the lid part and the inner cylinder part is not limited to a curved surface, but a throat shape that tapers conically from the inner peripheral surface of the inner cylinder part toward the edge of the outlet part of the lid part. Even in this case, troublesome work such as welding and processing is unnecessary, pressure loss due to rapid contraction of the flow path can be prevented, and the same effects as those of the second, third, and fourth embodiments can be obtained.

1 Screw compressor, 2 Compressor body, 3 Casing, 4 Oil separator, 5 Motor, 5a Stator, 5b Motor rotor, 6 Screw shaft, 7 Screw rotor, 7a Screw groove, 8 Bearing, 9 Gate rotor, 9a Teeth Part, 10 slide valve, 10a opening part, 11 compression chamber, 12 discharge chamber, 13 outer cylinder part, 14 inner cylinder part, 15 lid part, 15a outlet part, 16 bottom part, 17 wave plate, 18 check valve, 19 Oil reservoir, 20 Oil separator, 21 Outer cylinder, 22 Cylindrical lid, 22a Lid, 22b Inner cylinder, 22c Outlet, 30 Oil separator, 31 Cylindrical lid, 31a Lid, 31b Inner cylinder 31c outlet part, 31d current plate, 40 oil separator, 41 outer cylinder part, 41d current plate

Claims (8)

A compressor body,
An oil separator that is configured integrally with the compressor main body, and that separates the gas and oil discharged from the compressor main body by swirling,
The oil separator includes an outer cylinder part that swirls and lowers the gas and oil discharged from the compressor main body part, and the gas separated from the oil is provided outside the oil separator. An inner cylinder part to be led to
The compressor characterized in that the inner peripheral surface of the inner cylinder part has a larger surface roughness than the outer peripheral surface of the inner cylinder part. The inner cylinder part is formed by casting,
The compressor according to claim 1, wherein an inner peripheral surface of the inner cylinder portion remains a cast surface. Provided so as to cover the upper opening of the outer cylinder part, provided with a lid part integrally formed by casting with the inner cylinder part,
The boundary between the lid part and the inner cylinder part forms a smooth curved surface from an edge of an upper and lower through hole provided in the center of the lid part to an inner peripheral surface of the inner cylinder part. The compressor according to claim 1 or 2. Provided so as to cover the upper opening of the outer cylinder part, provided with a lid part integrally formed by casting with the inner cylinder part,
The boundary between the lid part and the inner cylinder part forms a throat shape that spreads in a conical shape from the edge of the upper and lower through holes provided in the center of the lid part to the inner peripheral surface of the inner cylinder part. The compressor according to any one of claims 1 to 3. 2. A rectifying plate that is integrally formed with the inner cylinder part by casting and that divides an opening cross section of the inner space in the inner cylinder part is provided below the inner cylinder part. 4. The compressor according to any one of 4. A wave plate that is provided in the lower part of the outer cylinder part and extends in parallel with the opening surface of the inner cylinder part,
It is integrally formed with the outer cylinder by casting,
6. The compression according to claim 1, further comprising: a rectifying plate provided to divide an opening cross section of the outer cylinder portion in a space between the inner cylinder portion and the wave plate. Machine. The compressor according to claim 6, wherein the rectifying plate is provided at a position lower than an intermediate position of a lower end surface of the inner cylinder portion from an upper surface of the wave shaping plate. The compressor is a screw compressor having a casing constituting an outer shell, a screw rotor disposed rotatably in the casing, and a compression chamber partitioned by the casing and the screw rotor, A compressor according to any one of claims 1 to 7, wherein a check valve for preventing a backflow of gas from the oil separator is provided on the outlet side of the oil separator.

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