WO2022181296A1

WO2022181296A1 - Oil separator and compressor for cryogenic refrigerator

Info

Publication number: WO2022181296A1
Application number: PCT/JP2022/004514
Authority: WO
Inventors: 祐貴大谷
Original assignee: 住友重機械工業株式会社
Priority date: 2021-02-24
Filing date: 2022-02-04
Publication date: 2022-09-01
Also published as: CN116802444A; TW202234003A

Abstract

This oil separator (20) comprises: an oil separator container (44); a refrigerant gas introduction pipe (52) which is inserted from above the oil separator container (44) and introduces a refrigerant gas into the oil separator container (44); and a filter element (46) which is disposed inside the oil separator container (44) and defines an outer cavity (48) between the oil separator container (44) and the filter element, the filter element (46) having an inner cavity (50) which is connected to the refrigerant gas introduction pipe (52) and to which the refrigerant gas is introduced from the refrigerant gas introduction pipe (52), and separating oil from the refrigerant gas flowing to the outer cavity (48) from the inner cavity (50). The filter element (46) comprises a lower plate-shaped body (60) attached to the lower end thereof, and the oil separator container (44) is joined to the lower plate-shaped body (60) at the bottom part thereof.

Description

Compressors for oil separators and cryogenic refrigerators

The present invention relates to an oil separator and a cryogenic refrigerator compressor.

Refrigerant gas compressors used in cryogenic refrigerators often have an oil separator and an adsorber to remove oil from the compressed and pressurized refrigerant gas. The refrigerant gas entering the oil separator contains some oil. Most of the oil is separated from the refrigerant gas by the oil separator, but a small amount of oil may flow out from the oil separator together with the refrigerant gas. It is adsorbed by the adsorber and removed from the refrigerant gas.

JP 2012-202635 A

After studying the above compressor, the inventor recognized that the filter element in the oil separator had room for improvement from the viewpoint of manufacturing cost reduction.

One exemplary objective of certain aspects of the present invention is to reduce manufacturing costs for filter elements within oil separators.

According to one aspect of the present invention, the oil separator comprises an oil separator container, a refrigerant gas introduction pipe inserted from the top of the oil separator container and introducing refrigerant gas into the oil separator container, and an oil separator arranged in the oil separator container. , the filter element defining an outer cavity between itself and the oil separator container, the filter element having an inner cavity connected to a refrigerant gas introduction pipe and through which refrigerant gas is introduced from the refrigerant gas introduction pipe, the refrigerant flowing from the inner cavity to the outer cavity. a filter element for separating oil from gas. The filter element has a lower dish attached to its lower end, and the oil separator container is joined to the lower dish at its bottom.

According to one aspect of the present invention, the oil separator comprises an oil separator container, a refrigerant gas introduction pipe inserted from the top of the oil separator container and introducing refrigerant gas into the oil separator container, and an oil separator arranged in the oil separator container. , the filter element defining an outer cavity between itself and the oil separator container, the filter element having an inner cavity connected to a refrigerant gas introduction pipe and through which refrigerant gas is introduced from the refrigerant gas introduction pipe, the refrigerant flowing from the inner cavity to the outer cavity. a filter element for separating oil from gas. The filter element is attached to its upper end and has an upper dish-shaped body having a concave portion recessed toward the inner cavity. and recesses.

According to an aspect of the present invention, a cryogenic refrigerator compressor includes any one of the oil separators described above.

According to the present invention, manufacturing costs can be reduced for the filter element in the oil separator.

1 is a diagram schematically showing a cryogenic refrigerator according to an embodiment; FIG. It is a sectional view showing roughly an oil separator concerning an embodiment.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description and drawings, the same or equivalent components, members, and processes are denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate. The scales and shapes of the illustrated parts are set for convenience in order to facilitate explanation, and should not be construed as limiting unless otherwise specified. The embodiment is an example and does not limit the scope of the present invention. All features and combinations thereof described in the embodiments are not necessarily essential to the invention.

FIG. 1 is a diagram schematically showing a cryogenic refrigerator according to an embodiment.

The cryogenic refrigerator 10 includes a compressor 12 and a cold head 14. The compressor 12 is configured to recover the refrigerant gas of the cryogenic refrigerator 10 from the cold head 14 , pressurize the recovered refrigerant gas, and supply the refrigerant gas to the cold head 14 again. Compressor 12 is also referred to as a compressor unit. The cold head 14, also called an expander, has a room temperature section 14a and a cold section 14b, also called a cooling stage. Compressor 12 and cold head 14 constitute a refrigeration cycle of cryogenic refrigerator 10, which cools low temperature section 14b to a desired cryogenic temperature. The refrigerant gas, also called working gas, is typically helium gas, although other suitable gases may be used.

Cryogenic refrigerator 10 is illustratively a single stage or two stage Gifford-McMahon (GM) refrigerator, but may also be a pulse tube refrigerator, Stirling refrigerator, or other type of cryogenic refrigerator. It may be a refrigerator. The coldhead 14 has a different configuration depending on the type of cryogenic refrigerator 10 , but the compressor 12 can have the configuration described below regardless of the type of cryogenic refrigerator 10 .

In general, the pressure of the refrigerant gas supplied from the compressor 12 to the cold head 14 and the pressure of the refrigerant gas recovered from the cold head 14 to the compressor 12 are both significantly higher than the atmospheric pressure. It can be called a second high voltage. For convenience of explanation, the first high pressure and the second high pressure are also simply referred to as high pressure and low pressure, respectively. Typically the high pressure is eg 2-3 MPa. The low pressure is for example 0.5-1.5 MPa, for example about 0.8 MPa.

The compressor 12 includes a compressor body 16, an oil line 18, an oil separator 20, and an adsorber 21. The compressor 12 also includes a discharge port 22 , a suction port 24 , a discharge flow path 26 , a suction flow path 28 , a storage tank 30 , a bypass valve 32 , a refrigerant gas cooling section 34 and an oil cooling section 36 .

The compressor main body 16 is configured to internally compress the refrigerant gas sucked from its suction port and discharge it from its discharge port. The compressor main body 16 may be, for example, a scroll type, rotary type, or other pump that pressurizes the refrigerant gas. Compressor body 16 may be configured to deliver a fixed, constant refrigerant gas flow rate. Alternatively, the compressor main body 16 may be configured to vary the flow rate of the discharged refrigerant gas. Compressor body 16 is sometimes referred to as a compression capsule.

The compressor body 16 uses oil for cooling and lubrication, and the sucked refrigerant gas is directly exposed to this oil inside the compressor body 16 . Therefore, the refrigerant gas is sent out from the discharge port in a state in which oil is slightly mixed.

The oil line 18 includes an oil circulation line 18a and an oil return line 18b. The oil circulation line 18a has an oil cooling portion 36, and is configured such that oil flowing out of the compressor main body 16 is cooled by the oil cooling portion 36 and flows into the compressor main body 16 again. The oil circulation line 18a is provided with an orifice for controlling the flow rate of oil flowing therein. Further, the oil circulation line 18a may be provided with a filter for removing dust contained in the oil. The oil return line 18 b connects the oil separator 20 to the suction flow path 28 in order to return the oil collected by the oil separator 20 to the compressor body 16 . A filter for removing dust contained in the oil separated by the oil separator 20 and an orifice for controlling the amount of oil returned to the compressor body 16 may be provided in the middle of the oil return line 18b.

The oil separator 20 is provided to separate the oil mixed in the refrigerant gas from the refrigerant gas as it passes through the compressor body 16 . The oil separator 20 is connected to the discharge port of the compressor main body 16 through the upstream portion 26a of the discharge passage 26. As shown in FIG. Further, the oil separator 20 is connected to the discharge port 22 through the downstream portion 26b of the discharge flow path 26. As shown in FIG. Details of the oil separator 20 will be described later.

The adsorber 21 is provided to remove, for example, vaporized oil and other contaminants remaining in the refrigerant gas from the refrigerant gas by adsorption. Adsorber 21 is arranged in the middle of downstream portion 26 b of discharge channel 26 .

The discharge port 22 is a refrigerant gas outlet installed in the compressor housing 38 for sending out the refrigerant gas pressurized to a high pressure by the compressor body 16 from the compressor 12, and the suction port 24 is a low pressure refrigerant gas outlet. A refrigerant gas inlet located in the compressor housing 38 for receiving the gas into the compressor 12 . The compressor housing 38 accommodates each component of the compressor 12 such as the compressor main body 16 and the oil separator 20 . A discharge port of the compressor body 16 is connected to the discharge port 22 by a discharge channel 26 , and a suction port 24 is connected to a suction port of the compressor body 16 by a suction channel 28 .

The storage tank 30 is provided as a volume for removing pulsation contained in the low pressure refrigerant gas returning from the cold head 14 to the compressor 12 . The storage tank 30 is arranged in the suction flow path 28 .

The bypass valve 32 connects the discharge passage 26 to the suction passage 28 so as to bypass the compressor body 16 . As an example, the bypass valve 32 branches from the downstream portion 26 b of the discharge flow path 26 between the oil separator 20 and the adsorber 21 and is connected to the suction flow path 28 between the compressor body 16 and the storage tank 30 . The bypass valve 32 is provided for refrigerant gas flow rate control and/or for pressure equalization between the discharge passage 26 and the suction passage 28 when the compressor 12 is stopped.

The refrigerant gas cooling unit 34 and the oil cooling unit 36 constitute a cooling system that cools the compressor 12 using a cooling medium such as cooling water. The refrigerant gas cooling part 34 is arranged in the upstream part 26 a of the discharge passage 26 and is provided to cool the high-pressure refrigerant gas heated by the heat of compression generated as the refrigerant gas is compressed in the compressor main body 16 . ing. The refrigerant gas cooling unit 34 cools the refrigerant gas by heat exchange between the refrigerant gas and the cooling medium. Further, the oil cooling portion 36 cools the oil by heat exchange between the oil flowing out from the compressor main body 16 and the cooling medium. A cooling medium is supplied to the compressor 12 from the outside, passes through the refrigerant gas cooling section 34 and the oil cooling section 36, and is discharged to the outside of the compressor 12. As shown in FIG. In this way, the heat of compression generated in the compressor body 16 is removed out of the compressor 12 along with the cooling medium. The cooling medium may be cooled by, for example, a chiller (not shown) and supplied again.

The cryogenic refrigerator 10 also includes a high pressure port 40 and a low pressure port 41 in the room temperature section 14 a of the cold head 14 . The high pressure port 40 is connected to the discharge port 22 by a high pressure pipe 42 and the low pressure port 41 is connected to the suction port 24 by a low pressure pipe 43 .

Therefore, refrigerant gas recovered from the cold head 14 into the compressor 12 flows from the low pressure port 41 through the low pressure pipe 43 into the suction port 24 of the compressor 12 . The refrigerant gas passes through the storage tank 30 on the suction flow path 28 and is recovered to the suction port of the compressor main body 16 . Refrigerant gas is compressed by the compressor main body 16 and raised in pressure. Refrigerant gas sent out from the discharge port of the compressor main body 16 passes through the refrigerant gas cooling portion 34 on the discharge passage 26 , the oil separator 20 , and the adsorber 21 and exits the compressor 12 from the discharge port 22 . Refrigerant gas is supplied to the inside of the cold head 14 through the high pressure pipe 42 and the high pressure port 40 .

FIG. 2 is a cross-sectional view schematically showing the oil separator 20 according to the embodiment.

The oil separator 20 includes an oil separator container 44 and a filter element 46. A filter element 46 is positioned within the oil separator container 44 and defines an outer cavity 48 therebetween. The filter element 46 also has an inner cavity 50 into which refrigerant gas is introduced to separate the oil from the refrigerant gas flowing from the inner cavity 50 to the outer cavity 48 .

The oil separator 20 is configured as a vertical oil separator. The oil separator 20 has an elongated cylindrical shape and is installed in the compressor 12 so that its longitudinal direction is aligned with the vertical direction. Refrigerant gas (entrained with some oil) entering from the compressor body 16 shown in FIG. The refrigerant gas cleaned by the filter element 46 is discharged from the upper portion of the oil separator 20 to the outside of the oil separator 20 . The oil separated from the refrigerant gas by the filter element 46 flows vertically down inside or on the surface of the filter element 46 and is collected from the bottom of the oil separator 20 .

The oil separator container 44 is a cylindrical container that defines the outer shape of the oil separator 20, and includes a container cylindrical portion 44a, a container upper lid 44b, and a container lower lid 44c. A container upper lid 44b is fixed to the upper end of the container tubular portion 44a, and a container lower lid 44c is fixed to the lower end of the container tubular portion 44a. The container upper lid 44b and the container lower lid 44c are each fixed to the container cylindrical portion 44a by, for example, welding, and the oil separator container 44 is an airtight container.

A refrigerant gas inlet pipe 52, a refrigerant gas outlet pipe 54, and a return oil pipe 56 are provided on the container upper lid 44b. The refrigerant gas introduction pipe 52 corresponds to a portion where the upstream portion 26a of the discharge passage 26 shown in FIG. The refrigerant gas lead-out pipe 54 corresponds to a portion where the downstream portion 26b of the discharge flow path 26 is connected to the oil separator 20 . The return oil pipe 56 corresponds to a portion where the oil return line 18 b of the oil line 18 connects to the oil separator 20 .

The refrigerant gas introduction pipe 52 is inserted from the top of the oil separator container 44 and introduces the refrigerant gas into the oil separator container 44 . The refrigerant gas introduction pipe 52 is provided through the container top lid 44b. Refrigerant gas introduction pipe 52 extends along the central axis of oil separator 20 . A refrigerant gas introduction pipe 52 passing through the container top lid 44b extends to the inner cavity 50 of the filter element 46 and is connected to the inner cavity 50 . Refrigerant gas is introduced from the outside of the oil separator 20 into the inner cavity 50 of the filter element 46 through the refrigerant gas introduction pipe 52 .

In the example shown in FIG. 2, the refrigerant gas introduction pipe 52 extends to the vicinity of the bottom of the inner cavity 50. When the tip 52a of the refrigerant gas introduction pipe 52 is positioned below half the height of the inner cavity 50 as described above, the tip 52a of the refrigerant gas introduction pipe 52 is positioned half the height of the inner cavity 50. The amount of oil discharged from the refrigerant gas lead-out pipe 54 without being separated and collected from the refrigerant gas by the oil separator 20 (also referred to as the amount of oil rise) tends to be smaller than when positioned above.

The refrigerant gas lead-out pipe 54 is provided through the container upper lid 44b. The refrigerant gas lead-out pipe 54 passing through the container top cover 44b opens in the outer cavity 48 near the container top cover 44b, for example, between the container top cover 44b and the filter element 46 in the axial direction of the oil separator 20. Refrigerant gas flowing from the inner cavity 50 through the filter element 46 to the outer cavity 48 is discharged to the outside of the oil separator 20 through the refrigerant gas lead-out pipe 54 .

The return oil pipe 56 is provided through the container upper lid 44b. A return oil pipe 56 passing through the container upper lid 44b extends along the container cylindrical portion 44a to the vicinity of the container lower lid 44c. The return oil pipe 56 opens in the outer cavity 48 near the lower container lid 44c, for example, between the filter element 46 and the lower container lid 44c in the axial direction of the oil separator 20. As shown in FIG. Oil separated from the refrigerant gas by the filter element 46 is discharged to the outside of the oil separator 20 through the return oil pipe 56 .

The filter element 46 includes a filter body 58, and a lower dish-shaped body 60 and an upper dish-shaped body 62 that sandwich the filter body 58 from above and below. The filter body 58 includes an inner cylinder member 58a, a filter member 58b, and an outer cylinder member 58c.

The lower dish-shaped body 60 is attached to the lower end of the filter body 58 and joined to the bottom of the oil separator container 44, for example, the container lower lid 44c. The upper dish-shaped body 62 is attached to the upper end of the filter body 58 and joined to the refrigerant gas introduction pipe 52 . The refrigerant gas introduction pipe 52 extends through the central portion of the upper dish-shaped body 62 and into the inner cavity 50 . The upper dish-shaped body 62 and the lower dish-shaped body 60 are disc-shaped members made of metal such as stainless steel.

The filter element 46 is joined to the oil separator container 44 by fitting. Specifically, the lower dish-shaped body 60 has a first fitting portion 60a, and the bottom portion of the oil separator container 44 has a second fitting portion 64 that fits with the first fitting portion 60a. The first fitting portion 60 a is formed in the lower dish-shaped body 60 as a concave portion recessed toward the inner cavity 50 . The second fitting portion 64 is a convex portion protruding upward from the center portion of the container lower lid 44c of the oil separator container 44 .

The lower dish-shaped body 60 and the upper dish-shaped body 62 may be formed, for example, by pressing a metal plate. The second fitting portion 64 is prepared as a component separate from the container lower lid 44c of the oil separator container 44, and may be fixed to the container lower lid 44c by an appropriate method such as screwing or spot welding. Alternatively, the second fitting portion 64 may be formed integrally with the container bottom lid 44c by, for example, cutting a base material.

The upper dish-shaped body 62 is attached to the upper end of the filter body 58 and has a concave portion 62a recessed toward the inner cavity 50. The refrigerant gas introduction pipe 52 is inserted into the inner cavity 50 from the recess 62a of the upper dish-shaped body 62 and is bonded to the upper dish-shaped body 62 at the recess 62a. An insertion hole for inserting the refrigerant gas introduction pipe 52 into the inner cavity 50 is formed in the bottom surface of the recess 62a, and the refrigerant gas introduction pipe 52 inserted here is adhered to the side surface of the recess 62a. Agent 66 is filled. The adhesive 66 may be a sealing agent such as an epoxy adhesive or a silicon adhesive.

In this embodiment, the upper dish-shaped body 62 has the same shape as the lower dish-shaped body 60 except that the concave portion 62a of the upper dish-shaped body 62 has an insertion hole for the refrigerant gas introduction pipe 52 . By forming a through hole in the first fitting portion 60 a of the lower dish-shaped body 60 , this can be used as the upper dish-shaped body 62 . Since the same parts as the lower dish-shaped body 60 can be used for the upper dish-shaped body 62, the manufacturing cost can be reduced as compared with the case where they are designed as separate parts.

The lower dish-shaped body 60 and the upper dish-shaped body 62 are respectively adhered to the upper and lower portions of the filter body 58 with an adhesive, for example. Adhesive-impregnated portions 68 are formed in the upper and lower portions of the filter member 58b. As with the adhesive 66 described above, the adhesive may be an epoxy-based adhesive, a silicone-based adhesive, or the like, which has sealing properties. Thereby, it is possible to prevent the occurrence of gaps between the filter body 58 and the upper dish-shaped body 62 and between the filter body 58 and the lower dish-shaped body 60 . It is possible to prevent the refrigerant gas introduced into the inner cavity 50 from the refrigerant gas introduction pipe 52 and the oil separated from the refrigerant gas and liquefied from flowing out to the outer cavity 48 through the gap while containing the oil.

The lower dish-shaped body 60 has an annular depression that serves as a reservoir for the adhesive between the outer edge 60b of the lower dish-shaped body 60 and the first fitting portion 60a. When an uncured liquid adhesive is applied to this recess in the manufacturing stage, the first fitting portion 60a acts as an inner wall to prevent the adhesive from entering the inner cavity 50, and the outer edge 60b serves as an adhesive. Acts as an outer dike to prevent leakage to the outside. The end (lower end) of the filter body 58 is inserted into this adhesive receiving tray, and the filter body 58 is adhered to the lower dish-shaped body 60 . Therefore, as illustrated, the height of the first fitting portion 60a (and the height of the outer edge 60b) in the axial direction of the oil separator 20 (vertical direction in the figure) is higher than the height of the adhesive-impregnated portion 68. It's becoming Further, the adhesive-impregnated portion 68 is radially sandwiched between the first fitting portion 60a and the outer edge 60b.

By setting the height of the first fitting portion 60a in the axial direction to be the same as or slightly higher than the height of the outer edge 60b, the penetration of the adhesive into the inner cavity 50 can be more reliably suppressed. .

Similarly, the upper plate-like body 62 is also formed with an annular recess serving as a receiving tray for the adhesive between the outer edge 62b and the recess 62a. 58 is adhered to the upper plate-like body 62 .

The inner tubular member 58a of the filter body 58 is a tubular (for example, cylindrical) member formed of a punching plate made of stainless steel or carbon steel, for example. The inner cylindrical member 58 a is arranged coaxially with the central axis of the oil separator 20 so as to surround the refrigerant gas lead-out pipe 54 . The inner cylindrical member 58a is provided to support the filter member 58b from inside. The internal space of the inner cylinder member 58 a is the inner cavity 50 , and the inner cavity 50 is surrounded by the inner cylinder member 58 a, the upper dish-shaped body 62 and the lower dish-shaped body 60 .

The filter member 58b has a cylindrical shape and surrounds the inner cavity 50. The filter member 58b is also arranged coaxially with the central axis of the oil separator 20 . The filter member 58b has the inner cylinder member 58a as a core, and is provided by winding a filter material in a cylindrical shape around the inner cylinder member 58a. Filter member 58 b occupies most of the volume of filter body 58 . The filter member 58b is made of mineral fiber such as glass wool or other filter material.

The outer cylindrical member 58c is a tubular (for example, cylindrical) member formed of a punching plate made of stainless steel or carbon steel, for example, and is arranged coaxially with the central axis of the oil separator 20 so as to surround the filter member 58b. . The outer cavity 48 is adjacent just outside the outer cylinder member 58c. The outer cylinder member 58c reinforces the filter member 58b from the outside, and the inner cylinder member 58a reinforces the filter member 58b from the inside. It should be noted that it is not essential that the inner cylindrical member 58a and the outer cylindrical member 58c are perforated plates, and a wire mesh, a plate provided with slits, a member in which bars are arranged in a lattice, or the like, can be used as a filter without hindering the flow of gas. Any structure may be used as long as it supports the member 58b.

In FIG. 2, for ease of understanding, the flow of refrigerant gas within the oil separator 20 is indicated by a white arrow G, and the flow of oil is indicated by a dark arrow OL. Refrigerant gas (G, OL) mixed with oil flows from the refrigerant gas introduction pipe 52 into the inner cavity 50 of the filter element 46 . Refrigerant gas G and oil OL are separated by the filter body 58 . Refrigerant gas G is delivered from the oil separator 20 through the refrigerant gas lead-out pipe 54 . Oil OL flows down to the bottom of oil separator container 44 and is collected through return oil pipe 56 .

By the way, in the existing oil separator, the filter element is suspended and supported in the oil separator container only by the refrigerant gas introduction pipe. Therefore, there is a concern that the filter element may shake within the oil separator container or hit the side of the container due to a strong external force during assembly of the oil separator or transportation to the site where it is used.

In order to avoid this, it is conceivable to add a reinforcing member to the oil separator. For example, the filter element may be provided with ribs projecting radially outward from the side surface of the filter element toward the side surface of the oil separator container, or vice versa. may be attached to the oil separator container to regulate the amount of displacement of the filter element due to shaking.

Alternatively, there is concern that the filter element may receive an axial load when the pressure loss of the gas passing through the filter element becomes excessive for some reason. To withstand such loads, a support bar may be provided that axially connects the upper and lower ends of the filter element.

However, such anti-vibration and load countermeasures increase the number of parts of the oil separator, resulting in an increase in manufacturing costs.

In the oil separator 20 according to the embodiment, the filter element 46 has a lower dish-shaped body 60 attached to its lower end. The oil separator container 44 is joined to the lower dish-shaped body 60 at its bottom. For joining purposes, the lower dish 60 has a first fitting portion 60a, and the bottom of the oil separator container 44 has a second fitting portion 64 that fits with the first fitting portion 60a.

In this way, the filter element 46 is supported by the refrigerant gas introduction pipe 52 at its upper end, and is also supported at its lower end by the fitting between the first fitting portion 60a and the second fitting portion 64. As shown in FIG. As a result, vibrations that may occur in the filter element 46 can be suppressed. It can also withstand axial loads that may occur on the filter element 46 . Compared to the case where additional members such as ribs and support bars are provided as described above, anti-vibration countermeasures can be realized with a simple structure, and manufacturing costs can be suppressed.

In addition, in the oil separator 20 according to the embodiment, the filter element 46 is attached to its upper end and provided with an upper plate-like body 62 having a concave portion 62 a recessed toward the inner cavity 50 . The refrigerant gas introduction pipe 52 is inserted into the inner cavity 50 from the recess 62a of the upper dish-shaped body 62 and is bonded to the upper dish-shaped body 62 at the recess 62a.

In existing oil separators, the refrigerant gas introduction pipe is often attached to the upper end of the filter element by welding. In this case, an additional member is required, such as providing an auxiliary plate for welding on the upper end of the filter element. However, according to the embodiment, the refrigerant gas introduction pipe 52 can be adhered to the upper dish-shaped body 62, and such an additional member is not required. Therefore, the manufacturing cost can be suppressed.

In addition, in the case of welding, an additional process separate from the bonding process is performed. This can be done at the same time as bonding to 60 and upper dish 62 and drying. This also leads to a reduction in manufacturing costs.

In addition, by bonding the refrigerant gas introduction pipe 52 to the upper dish-shaped body 62 together with bonding the lower end of the filter element 46 and the bottom of the oil separator container 44, stress concentration on the adhesive 66 can be suppressed. can.

Furthermore, in the oil separator 20 according to the embodiment, the first fitting portion 60 a is formed in the lower dish-shaped body 60 as a concave portion recessed toward the inner cavity 50 . In this case, it becomes easy to dispose the tip 52 a of the refrigerant gas introduction pipe 52 close to the bottom of the oil separator 20 . This improves the oil separation performance of the oil separator 20 as described above.

If the lower dish-shaped body 60 does not have the first fitting portion 60a and the lower dish-shaped body 60 is flat, when the filter body 58 is pressed against the lower dish-shaped body 60 for adhesion, the filter body 58 extrudes some of the adhesive into the inner cavity 50 causing the adhesive to build up in the inner cavity 50 . If the tip 52a of the refrigerant gas introduction pipe 52 is arranged sufficiently close to the bottom of the inner cavity 50, there is a concern that the swelling adhesive may reach the tip 52a and further block the tip 52a. In this way, when the surface facing the tip 52a is covered with adhesive, the distance between this facing surface (that is, the surface of the solidified adhesive) and the tip 52a depends on the amount of adhesive applied and how the bonding work is performed. Depends. To prevent the tip 52a from reaching the adhesive, it is necessary to raise the tip 52a to some extent. The tip 52a is separated from the bottom of the inner cavity 50, and the performance of the oil separator 20 may be affected.

However, in this embodiment, the tip 52a of the refrigerant gas introduction pipe 52 faces the first fitting portion 60a, and the height of the first fitting portion 60a is higher than the adhesive impregnated portion 68. As a result, the upper surface of the first fitting portion 60a facing the tip 52a is not covered with the adhesive and is exposed to the inner cavity 50. As shown in FIG. Since the adhesive has been removed from the upper surface of the first mating portion 60a opposite the tip 52a, the tip 52a can be positioned closer to the bottom of the inner cavity 50, which as described above is the oil separator 20. This leads to improved performance.

The refrigerant gas introduction pipe 52 may be provided with a positioning portion 52b. The positioning portion 52 b protrudes radially outward from the outer peripheral surface of the refrigerant gas introduction pipe 52 . The positioning portion 52 b may be formed in a flange shape around the entire circumference of the refrigerant gas introduction pipe 52 . Only by abutting the positioning portion 52b against the concave portion 62a, the tip 52a can be easily arranged at a specified distance from the upper surface of the first fitting portion 60a.

It should be noted that the positioning portion 52b is not limited to a specific shape. For example, the refrigerant gas introduction pipe 52 may have a large diameter at the top and a small diameter at the bottom, and the step between the large diameter portion and the small diameter portion may abut against the concave portion 62 a of the upper plate-like body 62 .

The present invention has been described above based on the examples. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that various design changes and modifications are possible, and that such modifications are within the scope of the present invention. By the way. Various features described in relation to one embodiment are also applicable to other embodiments. A new embodiment resulting from combination has the effects of each of the combined embodiments.

In the above-described embodiment, the second fitting portion 64 is a cylindrical convex portion protruding from the container lower lid 44c, but the second fitting portion 64 may have other shapes. . For example, the second fitting portion 64 may have a large diameter portion protruding from the container bottom lid 44c and a small diameter portion further projecting from the large diameter portion, and the small diameter portion fits with the first fitting portion 60a. may be combined. The upper surface of the large diameter portion may contact the lower surface of the lower dish 60 around the first fitting portion 60 a to support the filter element 46 .

The joining position by fitting the lower dish-shaped body 60 and the container lower lid 44c is not limited to the central portion of the lower dish-shaped body 60, but may be on the outer peripheral portion of the lower dish-shaped body 60. For example, the first fitting portion 60a may be formed in the lower dish-shaped body 60 as a recess outside the inner cavity 50 and recessed toward the filter member 58b. The second fitting portion 64 may be a convex portion projecting upward from the lower lid 44c of the oil separator container 44 at a position corresponding to the first fitting portion 60a.

In the above-described embodiment, the first fitting portion 60a is a concave portion and the second fitting portion 64 is a convex portion. The portion 64 may be a recess. The first fitting portion 60a may be a projection projecting from the lower dish-shaped body 60 toward the container bottom lid 44c, and the second fitting portion 64 may be a recess formed in the container bottom lid 44c. may

The joint between the lower portion of the filter element 46 and the bottom portion of the oil separator container 44 is not limited to a fitting structure. For example, the joint between the lower portion of the filter element 46 and the bottom of the oil separator container 44 is such that the lower surface of the filter element 46 (eg lower dish 60) and the bottom surface of the oil separator container 44 (eg container Support may be provided by contact with the lower lid 44c).

Although the present invention has been described using specific terms based on the embodiment, the embodiment only shows one aspect of the principle and application of the present invention, and the embodiment does not include the claims. Many variations and rearrangements are permissible without departing from the spirit of the invention as defined in its scope.

The present invention can be used in the fields of oil separators and compressors for cryogenic refrigerators.

10 cryogenic refrigerator, 12 compressor, 20 oil separator, 44 oil separator container, 46 filter element, 48 outer cavity, 50 inner cavity, 52 refrigerant gas introduction pipe, 60 lower dish-shaped body, 62 upper dish-shaped body.

Claims

an oil separator container;
a refrigerant gas introduction pipe that is inserted from the top of the oil separator container and introduces refrigerant gas into the oil separator container;
A filter element disposed within the oil separator container and defining an outer cavity between itself and the oil separator container, the filter element being connected to the refrigerant gas introduction pipe and into which the refrigerant gas is introduced from the refrigerant gas introduction pipe. a filter element for separating oil from the refrigerant gas flowing from the inner cavity to the outer cavity;
An oil separator, wherein said filter element has a lower dish-shaped body attached to its lower end, and said oil separator container is joined to said lower dish-shaped body at its bottom.
2. The lower dish-shaped body has a first fitting portion, and the bottom portion of the oil separator container has a second fitting portion that fits with the first fitting portion. Oil separator as described.
The oil separator according to claim 2, wherein the first fitting portion is formed in the lower dish-shaped body as a concave portion recessed toward the inner cavity.
The oil separator according to claim 3, wherein the second fitting portion has a projection projecting from the bottom cover of the oil separator container to the recess of the lower dish-shaped body.
5. The oil according to any one of claims 2 to 4, wherein the second fitting portion is in contact with the lower surface of the lower dish-shaped body around the first fitting portion to support the filter element. separator.
The filter element comprises a filter body having an adhesive-impregnated portion at its lower end,
The lower dish-shaped body has an outer edge forming an annular recess between itself and the first fitting portion, and the adhesive-impregnated portion is housed in the annular recess. The oil separator according to any one of claims 2 to 5.
The oil separator according to claim 6, wherein the first fitting portion and the outer edge of the lower dish-shaped body are higher than the adhesive-impregnated portion.
The filter element has an upper plate-like body attached to its upper end and having a concave portion recessed toward the inner cavity, and the refrigerant gas introduction pipe is inserted into the inner cavity from the concave portion of the upper plate-like body. 8. The oil separator according to any one of claims 1 to 7, wherein the oil separator is inserted and adhered to the upper dish-shaped body at the recess.
8. The refrigerant gas introduction pipe has a positioning portion that abuts against the concave portion of the upper dish-shaped body to position the tip of the refrigerant gas at a specified distance from the lower dish-shaped body. oil separator described in .
an oil separator container;
a refrigerant gas introduction pipe that is inserted from the top of the oil separator container and introduces refrigerant gas into the oil separator container;
A filter element disposed within the oil separator container and defining an outer cavity between itself and the oil separator container, the filter element being connected to the refrigerant gas introduction pipe and into which the refrigerant gas is introduced from the refrigerant gas introduction pipe. a filter element for separating oil from the refrigerant gas flowing from the inner cavity to the outer cavity;
The filter element has an upper plate-like body attached to its upper end and having a concave portion recessed toward the inner cavity, and the refrigerant gas introduction pipe is inserted into the inner cavity from the concave portion of the upper plate-like body. An oil separator characterized in that the oil separator is embedded and adhered to the upper plate-like body at the recess.
The oil separator according to claim 10, wherein the oil separator container has a bottom surface that supports the lower part of the filter element.
A cryogenic refrigerator compressor comprising the oil separator according to any one of claims 1 to 11.