JP2017089595A - Labyrinth piston type reciprocating compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a labyrinth piston type reciprocating compressor capable of preventing compression gas from leaking outside and being contaminated by lube oil, etc. while achieving the simple structure, weight saving, and low cost.SOLUTION: A labyrinth piston type reciprocating compressor comprises a seal device 30 for sealing between a cylinder 11 and a piston rod 21. The seal device 30 includes: a plurality of non-contact seal members 31 each sealing non-contact the outer peripheral surface 21a of the piston rod 21; a contact seal member 32 for sealing the outer peripheral surface 21a of the piston rod 21 by touching the outer peripheral surface 21a; a compression gas exhaust mechanism 33 that communicates with a clearance A between the piston rod 21 and the plurality of non-contact seal members 31 so as to discharge the compression gas flowing into the clearance A outside; and a barrier gas circulation mechanism 36 for circulating barrier gas through a clearance portion which is positioned between the contact seal member 32 and a position with which the compression gas exhaust mechanism 33 communicates out of the clearance A.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a labyrinth piston type reciprocating compressor.

  Conventionally, a labyrinth piston type reciprocating compressor using a labyrinth piston is known as a reciprocating compressor (see, for example, Patent Document 1). The labyrinth piston has a labyrinth groove on its outer peripheral surface, and uses a labyrinth effect generated in a gap with the cylinder to ensure airtightness with the cylinder. Therefore, the labyrinth piston does not use lubricating oil or a piston ring for ensuring airtightness. Therefore, the labyrinth piston type reciprocating compressor has a great advantage that a clean compressed gas that does not contain lubricating oil or piston ring wear powder can be obtained.

  In the labyrinth piston type reciprocating compressor (hereinafter also simply referred to as “compressor”), the labyrinth packing using the labyrinth effect is also used for the sealing device that seals between the cylinder and the piston rod for the reason described above. ing. However, in the sealing device using the labyrinth packing, due to the characteristics of the labyrinth packing, a slight leakage of compressed gas occurs from the compression chamber in the cylinder to the gap between the labyrinth packing and the piston rod. Therefore, especially when compressing toxic and flammable gases, it is necessary to prevent the compressed gas from flowing into the frame through this gap and leaking from there to the outside (atmosphere). Become.

  FIG. 3 is an enlarged cross-sectional view of the vicinity of a sealing device in a conventional labyrinth type reciprocating compressor. 3 includes a plurality of labyrinth packings 131 arranged along the axial direction of the piston rod 121, and a packing box 140 that stores and holds them. The packing box 140 includes a plurality of packing cases 141 for storing and holding the labyrinth packing 131, a packing presser 142 for storing and holding the lowest labyrinth packing 131, and an intermediate provided between the packing cases 141. And a ring 143. The plurality of packing cases 141 and the intermediate ring 143 are fixed to the cylinder 111 by the packing press 142 being fixed to the cylinder 111 by fixing bolts 146.

  Further, the sealing device 130 has a communication groove 133a formed on the inner peripheral surface of the intermediate ring 143, and a through flow formed through the packing case 141 so as to communicate the communication groove 133a with the outside of the compressor. And a path 133b. These function as a compressed gas discharge mechanism 133, and discharge the compressed gas flowing downward from the compression chamber (not shown) in the cylinder 111 into the gap between the piston rod 121 and the labyrinth packing 131 to the outside of the compressor. be able to. The compressed gas discharge mechanism 133 is connected to a recovery line (not shown) so that the compressed gas discharged is recovered and reused in the process.

  In addition, in the sealing device 130, the pressurized barrier gas flows upward from the frame side (the lower side in the figure) into the gap between the piston rod 121 and the labyrinth packing 131 and is discharged through the compressed gas discharge mechanism 133. It is comprised so that. Due to the circulation of the barrier gas, the compressed gas flowing in from the compression chamber in the cylinder 111 is blocked from further inflow when reaching the communication groove 133a, and flows to the compressed gas discharge mechanism 133 together with the barrier gas. be able to. As a result, leakage of compressed gas to the frame (not shown) can be prevented.

JP 2010-71174 A

  In the sealing device 130 shown in FIG. 3, it is necessary to introduce pressurized barrier gas into the frame in order to allow barrier gas to flow into the gap between the piston rod 121 and the labyrinth packing 131. For this reason, when the sealing device 130 shown in FIG. 3 is employed in a compressor, the frame structure becomes complicated, and the frame itself becomes thick, leading to an increase in weight and cost.

  In addition, a space called a distance chamber is provided in the frame adjacent to the sealing device 130, thereby ensuring a sufficient space between the sealing device 130 and the sliding member in the frame. However, there is a possibility that the lubricating oil used by the sliding member in the frame enters the distance chamber through the piston rod 121. In such a case, in the sealing device 130 shown in FIG. 3, the lubricating oil is mixed in the compressed gas recovered through the barrier gas, and as a result, the lubricating oil is also contained in the compressed gas generated by the compressor. It will be mixed.

  As a structure for preventing the mixture of the lubricating oil into the compressed gas, a structure in which a partition is provided in the distance chamber to form a two-chamber structure so that the lubricating oil does not enter the distance chamber on the cylinder side has been proposed. . However, in order to realize this, a significant change in the design of the frame is required, leading to further cost increase. In addition, if such a significant design change is made, there is a possibility that the original characteristics of the labyrinth piston cannot be utilized. That is, the piston rod of the labyrinth piston is movably supported only by the guide bearing provided in the lower part of the distance chamber. When the two-chamber configuration is used, the distance from the labyrinth piston to the guide bearing becomes long. For this reason, the vibration of the labyrinth piston is disturbed, and contact with the cylinder may occur.

  Accordingly, an object of the present invention is to provide a labyrinth piston that has a simple structure, realizes weight reduction and cost reduction, and prevents leakage of compressed gas to the outside and mixing of lubricating oil into the compressed gas. A reciprocating compressor is provided.

  In order to achieve the above-described object, a labyrinth piston type reciprocating compressor according to the present invention includes a cylinder that forms a compression chamber, a labyrinth piston that is reciprocally movable in the compression chamber, and a cylinder connected to the labyrinth piston. A plurality of piston rods that extend between the cylinder and the piston rod, and the sealing device is disposed on the outer circumferential surface of the piston rod along the axial direction of the piston rod. A plurality of non-contact seal members each sealing the outer peripheral surface in a non-contact manner, a contact seal member disposed at a position furthest from the compression chamber and contacting the outer peripheral surface to seal the outer peripheral surface; A plurality of seal members, a housing for storing and holding the plurality of seal members, and between the piston rod and the plurality of non-contact seal members A compressed gas discharge mechanism that communicates with the formed gap and discharges compressed gas flowing into the gap from the compression chamber to the outside of the labyrinth piston type reciprocating compressor, and the compressed gas discharge mechanism, Of these, a barrier gas flow mechanism for flowing the barrier gas through a gap portion located between the position where the compressed gas discharge mechanism communicates and the contact seal member is provided.

  In such a labyrinth piston type reciprocating compressor, the barrier gas flow mechanism introduces the barrier gas directly into the gap between the piston rod and a plurality of non-contact seal members (labyrinth packing) through the housing (packing box) of the sealing device. be able to. Thereby, unlike the conventional case, it is not necessary to introduce pressurized barrier gas into the frame. As a result, the frame structure of the compressor is not complicated, the frame itself is not thickened, and the apparatus is not increased in weight and cost. In addition, since the barrier gas circulation mechanism and the compressed gas discharge mechanism are provided independently, even if the lubricating oil adhering to the piston rod is discharged through the barrier gas distribution mechanism, it is compressed through the compressed gas discharge mechanism. There is no contact with gas.

  As described above, according to the present invention, a labyrinth piston that has a simple structure, realizes weight reduction and cost reduction, and can prevent leakage of compressed gas to the outside and mixing of lubricating oil into the compressed gas. A reciprocating compressor can be provided.

It is sectional drawing of the labyrinth type reciprocating compressor by one Embodiment of this invention. It is an expanded sectional view near the seal device in the labyrinth type reciprocating compressor according to the present embodiment. It is an expanded sectional view near the sealing device in the conventional labyrinth type reciprocating compressor.

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

  FIG. 1 is a cross-sectional view of a labyrinth type reciprocating compressor according to an embodiment of the present invention.

  A labyrinth piston type reciprocating compressor (hereinafter also simply referred to as “compressor”) 1 includes a gas compression unit 2 that compresses gas by a reciprocating movement of a piston, and a piston drive unit 3 that drives the piston. Yes.

  The gas compression unit 2 includes a cylinder 11 that forms a compression chamber 10, a labyrinth piston 12 that is provided in the compression chamber 10 so as to be capable of reciprocating, and a cylinder cover 13 that forms the compression chamber 10 together with the cylinder 11. Yes. The gas compression unit 10 can compress the gas in the compression chamber 10 by the reciprocating movement of the labyrinth piston 12 in the compression chamber 10. The labyrinth piston 12 has a labyrinth groove on the outer peripheral surface thereof, and ensures airtightness with the cylinder 11 by utilizing a labyrinth effect generated in a gap with the cylinder 11. The use of the labyrinth piston 12 eliminates the need for lubricating oil and piston rings for ensuring airtightness, and makes it possible to obtain clean compressed gas that does not contain lubricating oil and piston ring wear powder. In the present specification, the labyrinth piston is also simply referred to as “piston”.

  Further, the gas compression unit 2 includes a suction valve 15 provided in an intake chamber 14 formed in the cylinder 11 and communicating with the compression chamber 10, and a valve cover 16 that closes the intake chamber 14. The suction valve 15 is passively operated by the pressure difference between the intake chamber 14 and the compression chamber 10 to supply the gas introduced into the intake chamber 14 to the compression chamber 10. Open and close the communication port.

  Further, the gas compression unit 2 includes a discharge valve 18 provided in a discharge chamber 17 formed in the cylinder 11 and communicating with the compression chamber 10, and a valve cover 19 that closes the discharge chamber 17. The discharge valve 18 is passively operated by a pressure difference between the compression chamber 10 and the discharge chamber 17 in order to discharge the compressed gas compressed in the compression chamber 10 to the discharge chamber 17, and the compression chamber 10 and the discharge chamber 17. Open and close the communication port.

  The gas compression unit 2 forcibly opens the suction valve 15 to keep the compression chamber 10 open, thereby reducing the discharge capacity of the gas (compressed gas) discharged from the compression chamber 10 to the discharge chamber 17. It further has an unloader 19 for controlling. A known device can be used as the unloader 19. Therefore, description of the detailed configuration of the unloader 19 is omitted here.

  The piston drive unit 3 includes a piston rod 21, a cross head 22, a connecting rod 23, and a crankshaft 24 that are accommodated in the frame 20.

  The piston rod 21 is connected to the cross head 22 at one end, extends through the upper portion of the frame 20 and the lower portion of the cylinder 11, and is connected to the piston 12 at the other end. The cross head 22 is supported by the frame 20 so as to be movable along the axial direction of the piston rod 21. The connecting rod 23 is rotatably connected to the cross head 22 via the cross head pin 25. The crankshaft 24 is eccentrically connected to a rotating shaft of a drive unit (not shown), and supports the connecting rod 23 via a crankpin bearing 26 so as to be rotatable. With such a configuration, the piston drive unit 3 can convert the rotational motion of the crankshaft 24 into linear motion of the crosshead 22 (along the axial direction of the piston rod 21). 12 can be reciprocated.

  The piston rod 21 is supported by a guide bearing 27 provided on the frame 20 so as to be movable in the axial direction. An oil draining ring 28 for preventing the lubricating oil used in the piston drive unit 3 (cross head 22, crankshaft 24, guide bearing 27, etc.) from being lifted along the piston rod 21 is provided above the guide bearing 27. Is provided. Further, the piston rod 21 is provided with an oil retaining ring 29.

  On the upper side of the oil retaining ring 29, a sealing device 30 for sealing between the cylinder 11 and the piston rod 21 is provided. The sealing device 30 is provided with a space 20 a called a distance chamber between the oil draining ring 28. The distance chamber 20a is provided between the sealing device 30 and the oil draining ring 28 in order to ensure an interval equal to or greater than the stroke of the piston rod 21. The sealing device 30 of the present embodiment not only prevents the compressed gas in the compression chamber 10 from leaking into the frame 20, but also assumes that the lubricating oil used in the piston drive unit 3 has entered the above-described distance chamber 20a. Also, it has a function of preventing such lubricating oil from being mixed into the compressed gas in the compression chamber 10. Details of the sealing device 30 of this embodiment will be described later.

  Here, operation | movement of the compressor of this embodiment is demonstrated easily.

  The compressed gas is introduced into the intake chamber 14 from an intake pipe (not shown) connected to the intake chamber 14, and when the intake valve 15 is opened due to a pressure difference between the intake chamber 14 and the compression chamber 10, the compression chamber 10. Supplied to. The gas supplied to the compression chamber 10 is compressed by the reciprocating movement of the piston 13 driven by the piston drive unit 3. The compressed gas compressed in the compression chamber 10 is discharged into the discharge chamber 17 by opening the discharge valve 18 due to a pressure difference between the compression chamber 10 and the discharge chamber 17. When the compressed gas in the compression chamber 10 is discharged to the discharge chamber 17, the suction valve 15 is opened again, and the compressed gas is supplied to the compression chamber 10. By repeating such steps, compressed gas is continuously generated by the compressor 1.

  Next, the sealing device of the present embodiment will be described with reference to FIG. FIG. 2 is an enlarged cross-sectional view of the vicinity of the sealing device in the compressor of FIG.

  Referring to FIG. 2, the sealing device 30 includes a plurality of ring-shaped sealing members 31 and 32 disposed on the outer peripheral surface 21 a along the axial direction of the piston rod 21. Specifically, the sealing device 30 includes a plurality of labyrinth packings 31 and a resin packing 32 disposed below the labyrinth packings 31, that is, at a position farthest from the compression chamber 10 (not shown in FIG. 2). Have. Further, the sealing device 30 includes a packing box (housing) 40 that houses and holds the plurality of sealing members 31 and 32.

  The labyrinth packing 31 is a kind of non-contact sealing member that seals the outer peripheral surface 20a of the piston rod 21 in a non-contact manner. The labyrinth packing 31 is provided with a labyrinth groove on the inner peripheral surface facing the outer peripheral surface 20a of the piston rod 21, and utilizes the labyrinth effect generated in the gap. The plurality of labyrinth packings 31 are housed and held in packing cases 41, respectively. In the illustrated embodiment, five labyrinth packings 31 are provided, but the number of labyrinth packings 31 is not limited to this. In the following description, for convenience, the third, fourth, and fifth labyrinth packings 31a, 31b, and 31c from the top are referred to as first, second, and third labyrinth packings, respectively, and packing cases that hold them. 41a, 41b, and 41c are called and distinguished from the first, second, and third packing cases, respectively, but this distinction does not limit the present invention.

  The resin packing 32 is a type of contact seal member that contacts the outer peripheral surface 20a of the piston rod 21 and seals the outer peripheral surface 20a. The resin packing 32 of the present embodiment is preferably a packing made of a fluororesin, particularly polytetrafluoroethylene known as Teflon (registered trademark), because it has high heat resistance and a small friction coefficient. The resin packing 32 is housed and held in the packing presser 42 and slidably contacts the piston rod 21.

  The packing box 40 includes, in addition to the plurality of packing cases 41 and the packing retainers 42 described above, three intermediate rings 43, 44, and 45 provided therebetween. Specifically, the packing box 40 includes a first intermediate ring 43 disposed between the first packing case 41a and the second packing 41b, a second packing case 41b, and a third packing case 41c. And a second intermediate ring 44 disposed between the third packing 41c and the packing retainer 42. The packing box 40 is fixed to the cylinder 11 by the packing presser 42 being fixed to the cylinder 11 by fixing bolts 46.

  Further, the packing box 40 communicates three communication grooves 33 a, 34 a, 35 a formed on the inner peripheral surface facing the piston rod 21, and the communication grooves 33 a, 34 a, 35 a and the outside of the compressor 1. Three through channels 33b, 34b, and 35b are provided.

  The first communication groove 33a is connected to an inner circumference of the first intermediate ring 43 so as to communicate with a gap (hereinafter referred to as “rod gap”) A formed between the piston rod 21 and the plurality of labyrinth packings 31. Formed on the surface. The first through passage 33b is formed through the packing box 40 so as to communicate the first communication groove 33a and a primary vent line (not shown) outside the compressor 1. With such a configuration, the first communication groove 33 a and the first through flow path 33 b serve as a compressed gas discharge mechanism 33 that discharges the compressed gas flowing into the rod gap A from the compression chamber 10 to the outside of the compressor 1. Function.

  In the sealing device 30 of the present embodiment, by using the labyrinth packing 31, a slight leakage of compressed gas from the compression chamber 10 to the rod gap A occurs due to the characteristics. However, most of the compressed gas flowing along the outer peripheral surface 20a of the piston rod 21 flows into the first through passage 33b through the first communication groove 33a, and the compressor through the primary vent line. 1 will flow out to the outside. Thus, most of the compressed gas flowing from the compression chamber 10 into the rod gap A can be appropriately discharged through the compressed gas discharge mechanism 33 without leaking into the frame 20.

  The compressed gas discharged from the compressed gas discharge mechanism 33 is preferably recovered and reused in the process. Therefore, in this embodiment, the compressed gas discharge mechanism 33 is connected to a recovery line for returning the compressed gas to the compressor 1 through the primary vent line.

  On the other hand, the second communication groove 34 a is formed on the inner peripheral surface of the second intermediate ring 44 so as to communicate with the rod gap A. The second through channel 34b is formed through the packing box 40 so as to communicate the second communication groove 34a and a secondary vent line (not shown) outside the compressor 1. Further, the third communication groove 35 a is formed on the inner peripheral surface of the third intermediate ring 45 so as to communicate with the rod gap A. The third through passage 35b is formed through the packing box 40 so as to communicate the third communication groove 35a and a barrier gas supply line (not shown) outside the compressor 1.

  With such a configuration, the second communication groove 34 a and the second through flow path 34 b, and the third communication groove 35 a and the third through flow path 35 b include the third labyrinth packing in the rod gap A. It functions as a barrier gas circulation mechanism 36 that circulates the barrier gas through a gap with 31c. More specifically, the third communication groove 35a and the third through passage 35b function as a barrier gas supply mechanism 35 that supplies a barrier gas to the gap portion, and the second communication groove 34a and the second through passage are provided. 34 b functions as a barrier gas discharge mechanism 34 that discharges the barrier gas supplied to the gap portion to the outside of the compressor 1.

  The barrier gas circulation mechanism 36 has two functions: a function of blocking the compressed gas in the compression chamber 10 from flowing into the frame 20 and a function of blocking the lubricating oil in the frame 20 from being mixed into the compressed gas. doing. Hereinafter, these two functions will be described.

  As described above, most of the compressed gas flowing from the compression chamber 10 is appropriately discharged through the compressed gas discharge mechanism 33, that is, recovered. On the other hand, the remaining portion passes through the first communication groove 33a and flows into the gap between the piston rod 21 and the second labyrinth packing 31b. However, such compressed gas is blocked from further inflow by the barrier gas flowing through the barrier gas flow mechanism 36 and appropriately discharged together with the barrier gas to the outside of the compressor 1. In this way, the compressed gas flowing into the rod gap A from the compression chamber 10 that has not been discharged through the compressed gas discharge mechanism 33 can be appropriately discharged without leaking into the frame 20. In the present embodiment, the resin packing 32 prevents the barrier gas supplied to the gap portion through the barrier gas supply mechanism 35 from leaking into the frame 20.

  The compressed gas discharged together with the barrier gas from the barrier gas discharge mechanism 34 is discharged out of the system without being recovered, but may be recovered and reused in the process as necessary.

  On the other hand, the lubricating oil used in the piston drive unit 3 such as the cross head 22, the crankshaft 24, and the guide bearing 27 travels on the piston rod 21, and in some cases, the distance chamber 20a in the frame 20 (see FIG. 1). ). However, such lubricating oil may also be discharged out of the compressor 1 together with the barrier gas by blocking the contact with the compressed gas recovered through the compressed gas discharge mechanism 33 by the barrier gas flowing through the barrier gas distribution mechanism 36. it can. Furthermore, the presence of the barrier gas can also prevent the wear powder of the resin packing 32 from being mixed into the compressed gas. In this way, the compressed gas recovered through the compressed gas discharge mechanism 33 does not include the lubricating oil used in the frame 20, and as a result, the compressor 1 of the present embodiment does not contain the lubricating oil. Simple compressed gas can be produced. Therefore, in the present embodiment, it is important that the barrier gas circulation mechanism 36, particularly the barrier gas discharge mechanism 34, is provided independently of the compressed gas discharge mechanism 33.

  Thus, in the sealing device 30 of this embodiment, the barrier gas distribution mechanism 36 can supply and distribute the barrier gas directly into the packing box 40. Therefore, unlike the prior art, it is not necessary to introduce pressurized barrier gas into the frame 20. Therefore, the frame structure of the compressor 1 does not become complicated and the frame itself does not become thick, and as a result, the weight and cost of the apparatus can be suppressed. Also, the supply pressure of the barrier gas is sufficient to block the flow of the compressed gas that has not been discharged through the compressed gas discharge mechanism 33 into the frame 20, and the sealing device 30 of the present embodiment is also in this respect. It is advantageous.

  The barrier gas used in the present embodiment is preferably an inert gas, and particularly preferably nitrogen gas. In some cases, the same gas as the compressed gas can be used as the barrier gas.

  In the illustrated embodiment, five labyrinth packings 31 are provided, but as described above, the number of labyrinth packings 31 is not limited to this. For example, two or more labyrinth packings 31 may be provided between the first intermediate ring 43 and the second intermediate ring 44, and the second intermediate ring 44 and the third intermediate ring 45 Two or more labyrinth packings 31 may be provided between them. Also, four or more labyrinth packings 31 may be provided on the upper side of the first intermediate ring 43.

  Further, the arrangement of the through channels 33b, 34b, and 35b is not limited to the illustrated embodiment, and can be changed as appropriate. For example, the second through passage 34b of the barrier gas discharge mechanism 34 passes through the third packing case 41c, the third intermediate ring 45, and the packing retainer 42, similarly to the first through passage 33b. It may be formed.

DESCRIPTION OF SYMBOLS 1 Labyrinth piston type reciprocating compressor 2 Gas compression part 3 Piston drive part 10 Compression chamber 11 Cylinder 12 Labyrinth piston 13 Cylinder cover 14 Intake chamber 15 Intake valve 16, 19 Valve cover 17 Discharge chamber 18 Discharge valve 19 Unloader 20 Frame 21 Piston Rod 21a Outer peripheral surface 22 Cross head 23 Connecting rod 24 Crank shaft 25 Cross head pin 26 Crank pin bearing 27 Guide bearing 28 Oil retaining ring 29 Oil draining ring 30 Packing system A Rod clearance

Claims (8)

A labyrinth piston reciprocating compressor,
A cylinder that forms a compression chamber; a labyrinth piston that is reciprocally movable in the compression chamber; a piston rod that is coupled to the labyrinth piston and extends through the cylinder; and between the cylinder and the piston rod A sealing device for sealing,
The sealing device is
A plurality of seal members disposed on an outer peripheral surface of the piston rod along the axial direction of the piston rod, each of the non-contact seal members sealing the outer peripheral surface in a non-contact manner; and from the compression chamber A plurality of seal members including a contact seal member disposed at a farthest position and contacting the outer peripheral surface to seal the outer peripheral surface;
A housing for storing and holding the plurality of seal members;
Compressed gas communicating with a gap formed between the piston rod and the plurality of non-contact seal members and discharging compressed gas flowing into the gap from the compression chamber to the outside of the labyrinth piston type reciprocating compressor A discharge mechanism;
A barrier gas distribution mechanism that is provided independently of the compressed gas discharge mechanism, and that circulates the barrier gas in a gap portion located between the position where the compressed gas discharge mechanism communicates and the contact seal member in the gap. ,
Labyrinth piston type reciprocating compressor.   The labyrinth piston type reciprocating compressor according to claim 1, wherein the barrier gas flow mechanism supplies the barrier gas to the gap portion from the contact seal member side.   The barrier gas circulation mechanism includes a barrier gas supply mechanism that supplies the barrier gas to the gap portion, and a barrier gas discharge mechanism that discharges the barrier gas supplied to the gap portion to the outside of the labyrinth piston reciprocating compressor. The labyrinth piston type reciprocating compressor according to claim 1 or 2.   The barrier gas supply mechanism is formed on an inner peripheral surface of the housing facing the piston rod, and communicates with a communication groove that communicates with the gap, and the communication groove and the outside of the labyrinth piston reciprocating compressor. The labyrinth piston type reciprocating compressor according to claim 3, further comprising a through passage formed so as to penetrate through the housing.   The barrier gas discharge mechanism is formed on an inner peripheral surface of the housing facing the piston rod, and communicates with a communication groove that communicates with the gap portion, and the communication groove and the outside of the labyrinth piston reciprocating compressor. The labyrinth piston type reciprocating compressor according to claim 3, further comprising a through passage formed so as to penetrate the housing.   The compressed gas discharge mechanism is formed on an inner peripheral surface of the housing facing the piston rod, and communicates with a communication groove communicating with the gap, and the communication groove and the outside of the labyrinth piston reciprocating compressor. The labyrinth piston type reciprocating compressor according to any one of claims 1 to 5, further comprising a through passage formed so as to penetrate the housing.   The labyrinth piston type reciprocating compressor according to any one of claims 1 to 6, wherein the non-contact seal member is a labyrinth packing.   The labyrinth piston type reciprocating compressor according to any one of claims 1 to 7, wherein the contact seal member is a packing made of a fluororesin.

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