JP2003206860A - Reciprocating compressor, and piston, piston ring, tension ring, and distance ring used in this reciprocating compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reciprocating compressor, decreasing the number of consumption part items, which simplifies a maintenance work. <P>SOLUTION: This reciprocating compressor compresses gas by a piston 1 moved to reciprocate in a cylinder 41, and the piston 1 is provided with: a distance ring 3 mounted on a piston rod 2; a piston ring 5 mounted in a piston ring mounting groove 11 formed in an external periphery of the distance ring 3 to be divided into a plurality of parts; and a tension ring 6 energizing the piston ring 5 from an inner side to an outer direction. The piston ring 5 is fitted so as to come off in the outer direction relating to the piston ring mounting groove 11 of the distance ring 3, work of assembly/disassembly can be simplified, a long life of the piston ring can be attained, the work is simplified while a period of maintenance can be extended, and a cost of maintenance is held down. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating compressor for compressing gas such as air and nitrogen gas, and a piston, a piston ring, a tension ring and a distance ring used for the reciprocating compressor, which has no refueling mechanism. The present invention relates to a reciprocating compressor suitable for an oil-free type.

[0002]

2. Description of the Related Art Generally, reciprocating compressors are used for compressing air, nitrogen gas and the like in nitrogen gas production plants and the like. In this reciprocating compressor, as shown in FIG. 5, a piston 42 is reciprocally housed inside a cylinder 41, and the piston 42 is connected to a reciprocating device 44 via a piston rod 43. Cylinder 4 above
1, a suction pipe 45 for sucking gas into the cylinder 41.
And the discharge pipe 46 that discharges the gas compressed in the cylinder 41.

The suction pipe 45 is divided into a plurality of parts on the cylinder 41 side, and is located near both ends of the cylinder 41 (piston 42).
The suction valves 47 are connected to the front end side and the rear end side) and are provided near the respective connecting portions. Further, the cylinder 41 side of the discharge pipe 46 is branched into a plurality, and similarly, the cylinder 41
The discharge valves 48 are connected in the vicinity of both end portions (the front end side and the rear end side of the piston 42), and in the vicinity of the respective connecting portions. The suction valve 47 and the discharge valve 48 have a check valve structure in which gas flows only in the suction direction and the discharge direction, respectively.

In the reciprocating compressor, the reciprocating device 44 reciprocates the piston 42 to suck gas into the cylinder 41 and compress the gas in the cylinder 41 to discharge it into the discharge pipe 46.

That is, on the tip side of the piston 42, the gas is sucked into the cylinder 41 by retracting the piston 42 with the suction valve 47 open, and then the suction valve 47 is closed to close the piston 42. To discharge the compressed gas in the cylinder 41 to the discharge pipe 46 by opening the discharge valve 48 after compressing the gas in the cylinder 41. On the other hand, on the rear end side of the piston 42, the gas is sucked into the cylinder 41 by advancing the piston 42 with the intake valve 47 open, and then the intake valve 47 is closed and the piston 42 is retracted. After that, the gas in the cylinder 41 is compressed, and then the discharge valve 48 is opened, whereby the compressed gas in the cylinder 41 is discharged.
6 is to be discharged.

In the reciprocating compressor, a piston 42 as shown in FIG. 6 has been conventionally used. In this piston 42, a piston head 29 to which the rider ring 26 is attached is attached to a tip end portion of a piston rod 43. Further, a plurality of (six in this example) distance rings 33 to which the first and second piston rings 34 and 35 are attached are attached to the base side of the piston head 29. In the figure, 32 is a retaining ring for preventing the piston head 29 and the distance ring 33 from coming off from the tip of the piston rod 43, and 31.
Is a locking ring that prevents the piston head 29 and the distance ring 33 from being displaced toward the base side of the piston rod 43.

The rider ring 26 includes a cylinder 41.
It guides the reciprocating movement of the piston 42 inside, and a metal ring 27 made of stainless steel or the like and a resin ring 28 made of fluororesin or the like are integrated by shrink fitting. .

The first piston ring 34 and the second piston ring 35 prevent the gas compressed in the cylinder 41 from leaking due to the reciprocating motion of the piston 42 and receive the pressure generated by the compressed gas.

In the piston 42, the six distance rings 33 are arranged so that the front end side and the base side are the target through the partition ring 30. As a result, when the piston 42 advances toward the tip side,
The three first and second piston rings 34, 35 on the tip side mainly receive the pressure generated in the cylinder 41 on the tip side of the piston 42, and conversely, when the piston 42 retracts toward the root side, The pressure generated in the cylinder 41 on the root side of the piston 42 is received by the three first and second piston rings 34, 35 on the root side.

The first piston ring 34 is formed by kneading fluororesin and graphite having self-lubricating properties. The first piston ring 34 has a substantially L-shaped cross section, is divided into a plurality in the circumferential direction, and is urged outward from the inside by a tension ring 36 made of a metal material such as stainless steel. It is adapted to be pressed against the inner surface of the cylinder 41 to prevent gas leakage.

The first piston ring 34 has a piece having an L-shaped cross section, which is fitted into the recessed space 37 formed in the distance ring 33, so that when the wear of the first piston ring 34 progresses, The tension ring 36 is prevented from coming into contact with the inner surface of the cylinder 41, and the damage to the cylinder 41 is prevented.

The second piston ring 35 has the first piston ring 35.
The first piston ring 34 is prevented from being deformed by receiving the pressure of the compressed gas applied to the piston ring 34, and is arranged on the side opposite to the side on which the pressure of the first piston ring 34 is applied. The second piston ring 35 is made of a resin material such as fluororesin.

[0013]

In the above reciprocating compressor, the reciprocating compressor includes the first and second piston rings 3
Since 4 and 35 are consumable parts that are worn away by repeated sliding, maintenance work to be periodically replaced is required.

However, in order to prevent damage to the cylinder 41, a part of the first piston ring 34 is fitted into the hollow space 37 of the distance ring 33, so that the first and second piston rings 34, 35 are formed. When replacing the distance ring 33, once remove all the distance rings 33 from the piston rod 43, replace the first and second piston rings 34 and 35 with new ones, and then assemble all the distance rings 33 to the piston rod 43 again. Since the disassembling and assembling work must be performed, the maintenance work is extremely complicated and the maintenance cost is extremely high.

In the above conventional reciprocating compressor, the first
Since two types of piston rings, the piston ring 34 and the second piston ring 35, are used, the number of consumable parts is large, the cost of the consumable parts is high, and the cost of managing the parts and maintaining inventory is also high. .

The present invention has been made in view of the above circumstances, and provides a reciprocating compressor which has a small number of consumable parts and simplifies maintenance work, and a piston, a piston ring, a tension ring and a distance ring used therein. With the goal.

[0017]

In order to achieve the above object, a reciprocating compressor of the present invention is a reciprocating compressor for compressing gas by a piston that reciprocates in a cylinder.
The piston includes a distance ring attached to a piston rod, a plurality of divided piston rings attached to a piston ring attachment groove formed on the outer circumference of the distance ring, and urges the piston ring outward from the inside. The gist is that the piston ring is fitted to the piston ring mounting groove of the distance ring so as to be disengaged outward.

That is, in the reciprocating compressor of the present invention, the piston ring is fitted in the piston ring mounting groove of the distance ring so as to be disengaged outward. Therefore, the replacement of the piston ring is completed by directly removing the piston ring from the piston ring mounting groove of the distance ring and mounting a new one. In this way, the piston ring can be replaced without removing the distance ring from the piston rod, and therefore the disassembling and assembling work can be simplified. In addition, since the conventional structure is not designed to fit a part of the piston ring into the hollow space of the distance ring, it is possible to increase the contact area of the piston ring with the inner surface of the cylinder and reduce the sliding pressure. The life of the piston ring can be extended. Therefore, the maintenance cycle can be extended, the work can be extremely simplified, and the maintenance cost can be kept low.

Further, since the contact area between the inner surface of the cylinder and the piston ring can be made large and the contact pressure can be kept small, the deformation resistance of the piston ring can be improved and the conventional deformation prevention can be performed. Eliminates the need to use a two piston ring. Therefore, the number of consumable parts can be reduced, the cost of consumable parts can be reduced, and the cost for managing the parts and maintaining inventory can be reduced.

In the reciprocating compressor of the present invention, when the piston ring is in contact with the inner wall surface of the piston ring mounting groove of the distance ring via the straight surface, the shape of the distance ring and the piston ring is simple. This makes it easier to design and manufacture and avoid unnecessary cost increase. Further, in this case, when the straight surface is a surface that is substantially orthogonal to the sliding direction of the piston, the piston ring is supported by the straight surface, which prevents deformation of the piston ring. It effectively prevents abnormal wear such as uneven wear and is effective in extending the life of the piston ring.

In the reciprocating compressor of the present invention, when a plurality of the distance rings are provided, the plurality of piston rings can prevent the leakage of the high pressure gas, so that the compression at a higher compression rate can be achieved. It will be possible.

In the reciprocating compressor of the present invention, when the piston ring mounting groove of the distance ring is a notched groove formed from the outer peripheral surface of the distance ring to one of the disc surfaces, the shape of the distance ring is Further simplification, design and manufacturing can be facilitated, and unnecessary cost increase can be avoided. In addition, since the piston ring is held between the adjacent distance rings, the thickness ratio of the piston ring to the thickness of the distance ring can be increased, and the contact area with the inner surface of the cylinder is increased to reduce wear and increase the length. The life can be extended.

In the reciprocating compressor of the present invention, when the distance ring is attached so that the tip side and the root side are opposite in the longitudinal direction of the piston rod, when the piston moves forward and backward. Both are suitable for a compressor that compresses gas.

In the reciprocating compressor of the present invention, when the width of the tension ring is set to be smaller than the width of the piston ring, the outward biasing force against the piston ring becomes relatively small. As a result, the sliding pressure of the piston ring can be weakened, wear can be suppressed, and the service life can be extended.

In the reciprocating compressor of the present invention, when the tension ring is provided at the center of the width dimension of the piston ring, the outward biasing force applied to the piston ring is uniform in the width direction of the piston ring. It is possible to prevent abnormal wear such as uneven wear of the piston ring and prolong the service life.

In the reciprocating compressor of the present invention, when the piston ring is composed of fluororesin and molybdenum disulfide, the piston ring exhibits excellent rigidity and excellent self-lubricating property. The wear can be suppressed and the life can be extended.

In the reciprocating compressor of the present invention, when the tension ring is composed mainly of fluororesin, the outward biasing force against the piston ring is reduced and the sliding pressure of the piston ring is weakened. The wear can be suppressed and the life can be extended.

The piston, the piston ring, the tension ring and the distance ring of the present invention are used in the reciprocating compressor according to any one of claims 1 to 9.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail.

1 and 2 are views showing an example of a piston 1 used in a reciprocating compressor according to an embodiment of the present invention.

In this piston 1, a piston head 7 to which a rider ring 4 is attached is attached to the tip of a piston rod 2. Further, a plurality of (six in this example) distance rings 3 to which the piston rings 5 are attached are attached to the base side of the piston head 7. In the figure, 10 is a retaining ring that prevents the piston head 7 and the distance ring 3 from coming off from the tip of the piston rod 2, and 8 is the piston head 7.
The distance ring 3 is a locking ring that prevents the distance ring 3 from being displaced toward the base side of the piston rod 2.

The rider ring 4 guides the reciprocating motion of the piston 1 in the cylinder 41, and is made of a resin-bonded composite material in which fluororesin, molybdenum disulfide and carbon are bonded by a thermosetting resin (trade name: " Graflon HY-
50 "; Morganite Carbon Co., Ltd.). This piston ring 5 is formed by extruding or compression-pressing fluororesin, molybdenum disulfide, carbon and thermosetting resin, cutting it to a predetermined size, rolling it, putting it in a thermosetting jig, and firing it. It is manufactured by adding machining according to. The piston ring 5 thus obtained exists in a state in which the fluororesin is dispersed in a relatively small amount. As the piston ring 5, an extruded product having a fibrous structure and having excellent transverse rupture strength is preferably used.

The above-mentioned rider ring 4 is not a metal ring and a resin ring integrated by shrink fitting as in the prior art, but is divided into a plurality of pieces in the circumferential direction (two divisions in this example).
The piston head 7 is fitted into the rider ring mounting groove 12 so as to be disengaged outward. As a result, the replacement of the rider ring 4 is completed by directly removing the rider ring 4 from the rider ring mounting groove 12 and mounting a new one. Therefore, the disassembling and assembling work can be simplified, and the maintenance cost can be kept low.

In this example, the rider ring 4 is in contact with the inner wall surface of the rider ring mounting groove 12 via a straight surface. By doing so, the shapes of the piston head 7 and the rider ring 4 are simplified,
Designing and manufacturing can be facilitated and unnecessary cost increase can be avoided. Further, since the straight surface is a surface substantially perpendicular to the sliding direction of the piston, the rider ring 4 is supported by the straight surface, so that the rider ring 4 is prevented from being deformed and uneven wear or the like is prevented. Effectively prevent abnormal wear, rider ring 4
It is effective for prolonging the service life of.

The piston ring 5 prevents the gas compressed in the cylinder 41 from leaking due to the reciprocating motion of the piston 1 and receives the pressure generated by the compressed gas.

The piston ring 5 is mounted in a piston ring mounting groove 11 formed on the outer circumference of the distance ring 3 mounted on the piston rod 2. As shown in FIG. 2, the piston ring 5 is divided into a plurality of pieces (three pieces in this example) in the circumferential direction. As a mode of division, for example, it may be divided into a radial cut shape as shown in FIG. 2 (a) or a tangent cut shape as shown in FIG. 2 (b). Although the piston ring 5 is divided into three parts in this example, the present invention is not limited to this and may be divided into two parts or four or more parts.

On the inner peripheral surface of the piston ring 5, a tension ring 6 is formed at a substantially central portion in the thickness direction (width direction) thereof.
The tension ring fitting groove 13 for fitting is engraved.
The piston ring 5 has a tension ring fitting groove 1
The tension ring 6 fitted into the shaft 3 urges it outward from the inside. As a result, the piston ring 5 is pressed against the inner surface of the cylinder 41 to prevent the compressed gas from leaking.

The piston ring 5 is fitted in the piston ring mounting groove 11 of the distance ring 3 so as to be disengaged outward. That is, the piston ring mounting groove 11 of the distance ring 3
Is a notch-shaped groove formed from the outer peripheral surface of the distance ring 3 to the one board surface, and the distance ring is formed in a substantially L-shaped cross section. Then, the piston ring 5 is fitted into the piston ring mounting groove 11, so that the piston ring 5 becomes the distance ring 3
The inner wall surface of the piston ring mounting groove 11 and the board surface of the adjacent distance ring 3 are in contact with each other via a straight surface.

By doing so, the shape of the distance ring 3 is further simplified, designing and manufacturing are facilitated, and unnecessary increase in cost can be avoided.
Moreover, since the surface along the radial direction of the straight surface is a surface that is substantially orthogonal to the sliding direction of the piston 1, the piston ring 5 is supported by the straight surface, so that the piston ring 5 It is effective in extending the life of the piston ring 5 by preventing deformation of the piston ring 5 and abnormal wear such as uneven wear.

Further, since the piston ring 5 is held between the adjacent distance rings 3, the ratio of the thickness of the piston ring 5 to the thickness of the distance ring 3 can be increased and the contact area with the inner surface of the cylinder 41 can be increased. Is increased, wear is suppressed, and life can be extended.

The width dimension of the tension ring 6 is set to be smaller than the width dimension of the piston ring 5, and the tension ring 6 is provided at the center of the width dimension of the piston ring 5. Therefore, the outward biasing force on the piston ring 5 becomes relatively small, the sliding pressure of the piston ring 5 is weakened, and the outward biasing force applied to the piston ring 5 is reduced.
The width of the piston ring 5 becomes almost uniform, and abnormal wear such as uneven wear of the piston ring 5 can be prevented to prolong the service life.

The piston ring 5 is made of a resin-bonded composite material (trade name "Graflon HY-
50 "; Morganite Carbon Co., Ltd.). This piston ring 5 is formed by extruding or compression-pressing fluororesin, molybdenum disulfide, carbon and thermosetting resin, cutting it to a predetermined size, rolling it, putting it in a thermosetting jig, and firing it. It is manufactured by adding machining according to. The piston ring 5 thus obtained exists in a state in which the fluororesin is dispersed in a relatively small amount. As the piston ring 5, an extruded product having a fibrous structure and having excellent transverse rupture strength is preferably used. By doing so, the piston ring 5 exhibits excellent rigidity as well as excellent self-lubricating property, wear can be suppressed, and life can be extended.

The tension ring 6 is made of a composite material containing fluorocarbon resin as a main component and kneading graphite or carbon as a self-lubricating material. In this example, both graphite and carbon were mixed,
The present invention is not limited to this, and either one can be mixed, or other self-lubricating material such as graphite can be used. By doing so, the outward biasing force against the piston ring 5 is reduced, the sliding pressure of the piston ring 5 is weakened, wear is suppressed, and the life can be extended.

In the piston 1, the six distance rings 3 are attached in the longitudinal direction of the piston rod 2 so that the tip end side and the root side are opposite to each other with the partition ring 9 as a boundary. That is, the three distance rings 3 on the tip side of the partition ring 9 are notched grooves formed by the piston ring mounting groove 11 extending from the outer peripheral surface to the base surface on the root side.
1, a piston ring 5 is attached. On the other hand, the three distance rings 3 on the base side of the partition ring 9
Is a notch-shaped groove in which the piston ring mounting groove 11 is formed from the outer peripheral surface to the board surface on the tip side, and the piston ring 5 is mounted in the piston ring mounting groove 11.

By doing so, as will be described later, it becomes suitable for a compressor that compresses gas both when the piston 1 advances and when it retracts. Further, since the plurality of piston rings 5 can prevent the high-pressure gas from leaking further, it is possible to perform compression at a higher compression rate.

The piston 1 is used in the reciprocating compressor shown in FIG. 5 to form the reciprocating compressor of the present invention. Hereinafter, the reciprocating compressor of the present invention will be described with reference to FIG.

That is, in this reciprocating compressor, the piston 1 is reciprocally housed in the cylinder 41, and the piston 1 reciprocates via the piston rod 2.
Are linked to. The cylinder 41 includes the cylinder 4
1, a suction pipe 45 for sucking gas and a discharge pipe 46 for discharging the gas compressed in the cylinder 41 are communicated with each other.

The suction pipe 45 is divided into a plurality of parts on the cylinder 41 side, and is located near both ends of the cylinder 41 (piston 42).
The suction valves 47 are connected to the front end side and the rear end side) and are provided near the respective connecting portions. Further, the cylinder 41 side of the discharge pipe 46 is branched into a plurality, and similarly, the cylinder 41
The discharge valves 48 are connected near both ends (on the front end side and the rear end side of the piston 1) and near the respective connecting parts. The suction valve 47 and the discharge valve 48 have a check valve structure in which gas flows only in the suction direction and the discharge direction, respectively.

In the reciprocating compressor, the reciprocating device 44 reciprocates the piston 1 to suck the gas into the cylinder 41 and compress the gas in the cylinder 41 to discharge it into the discharge pipe 46.

That is, at the tip end side of the piston 1, the piston 1 is retracted with the intake valve 47 open to suck gas into the cylinder 41, and then the intake valve 47 is closed to close the piston 1. To discharge the compressed gas in the cylinder 41 to the discharge pipe 46 by opening the discharge valve 48 after compressing the gas in the cylinder 41. On the other hand, on the rear end side of the piston 1, by advancing the piston 1 with the intake valve 47 open, gas is sucked into the cylinder 41, and then the intake valve 47 is closed and the piston 1 is retracted. Let the cylinder 41
The compressed gas inside the cylinder 41 is discharged to the discharge pipe 46 by opening the discharge valve 48 after compressing the gas inside.

At this time, in the piston 5, since the six distance rings 3 are arranged so that the front end side and the base side are symmetrical with the partition ring 9 interposed therebetween,
When the piston 1 advances toward the tip side, the three piston rings 5 on the tip side mainly receive the pressure generated in the cylinder 41 on the tip side of the piston 1, and conversely, the piston 1 moves toward the root side. When retreating, the three piston rings 5 on the root side mainly receive the pressure generated in the cylinder 41 on the root side of the piston 1.

As described above, in the reciprocating compressor, the replacement of the piston ring 5 is completed by directly removing the piston ring 5 from the piston ring mounting groove 11 of the distance ring 3 and mounting a new one. In this way, the piston ring 5 can be replaced without removing the distance ring 3 from the piston rod 2, so that the disassembling and assembling work can be simplified. In addition, since the structure is not such that a part of the piston ring 5 is fitted into the hollow space of the distance ring 3 unlike the conventional case, it is possible to increase the contact area of the piston ring 5 with the inner surface of the cylinder 41, and to slide the piston ring 5. The pressure is reduced and the life of the piston ring 5 can be extended. Therefore, the maintenance cycle can be extended, the work can be extremely simplified, and the maintenance cost can be kept low.

Further, since the contact area between the inner surface of the cylinder 41 and the piston ring 5 can be made large and the contact pressure can be kept small, the deformation resistance of the piston ring 5 is improved and the conventional deformation prevention is possible. It is no longer necessary to use a second piston ring 35 for. Therefore,
The number of consumable parts can be reduced, the cost of consumable parts can be reduced, and the cost for managing parts and maintaining inventory can be reduced.

FIG. 3 shows another example of the piston used in the reciprocating compressor. 4A shows an example in which the side wall surface of the piston ring mounting groove 11 of the distance ring 3 is a tapered surface, and FIG. 3B shows a stepped portion on the side wall surface of the concave piston ring mounting groove 11. It is an example of being formed. Other than that, it is the same as that shown in FIG. 1, and has the same effect.

FIG. 4 shows another example of the piston used in the reciprocating compressor. In FIG. 4A, a concave piston ring mounting groove 11 is formed in the distance ring 3,
The piston ring is fitted in the piston ring mounting groove 11. FIG. 4B is an example in which both side wall surfaces of the concave piston ring mounting groove 11 are tapered surfaces.
(C) is an example in which step portions are formed on both side wall surfaces of the concave piston ring mounting groove 11. Other than that, it is the same as that shown in FIG. 1, and has the same effect.

In each of the above-mentioned embodiments, the six distance rings 3 are arranged so that the tip side and the root side are targeted via the partition ring 9, and when the piston 1 moves forward and backward. However, the present invention is not limited to this, and the plurality of distance rings 3 may be arranged only in one direction so that the gas is compressed only when the piston 1 moves forward. Good.

[0057]

As described above, according to the reciprocating compressor of the present invention, the replacement of the piston ring is completed by directly removing the piston ring from the piston ring mounting groove of the distance ring and mounting a new one. In this way, the piston ring can be replaced without removing the distance ring from the piston rod, and therefore the disassembling and assembling work can be simplified. In addition, unlike the conventional structure, a part of the piston ring is not fitted into the hollow space of the distance ring, so that it is possible to increase the contact area of the piston ring with the inner surface of the cylinder and reduce the sliding pressure. The life of the piston ring can be extended. Therefore, the maintenance cycle can be extended, the work can be extremely simplified, and the maintenance cost can be kept low.

Furthermore, since the contact area between the inner surface of the cylinder and the piston ring can be made large and the contact pressure can be kept small, the deformation resistance of the piston ring can be improved and the conventional deformation prevention Eliminates the need to use a two piston ring. Therefore, the number of consumable parts can be reduced, the cost of consumable parts can be reduced, and the cost for managing the parts and maintaining inventory can be reduced.

[Brief description of drawings]

FIG. 1 is a side view showing a piston used in an embodiment of a reciprocating compressor of the present invention.

FIG. 2 is a plan view showing a piston ring used in the reciprocating compressor.

FIG. 3 is a second piston used in the reciprocating compressor of the present invention.
It is a figure which shows an example-a 3rd example.

FIG. 4 is a fourth piston of the reciprocating compressor of the present invention.
It is a figure which shows an example-5th example.

FIG. 5 is a sectional view showing a conventional reciprocating compressor.

FIG. 6 is a side view showing a piston used in the conventional reciprocating compressor.

[Explanation of symbols]

1 piston 2 piston rod 3 distance ring 4 rider ring 5 piston rings 6 tension ring 7 piston head 8 Locking ring 9 partition ring 10 retaining ring 11 Piston ring mounting groove 12 Rider ring mounting groove 13 Tension ring fitting groove 26 Rider Ring 27 metal ring 28 resin ring 29 piston head 30 partition rings 31 Locking ring 32 retaining ring 33 distance ring 34 First Piston Ring 35 Second Piston Ring 36 tension ring 37 Numizumi space 41 cylinders 42 piston 43 Piston rod 44 Reciprocating device 45 Inhalation tube 46 Discharge pipe 47 suction valve 48 discharge valve

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takuji Yamamura             2-6-40 Chikko Shinmachi, Sakai City, Osaka Prefecture             Water Maintenance Co., Ltd. F term (reference) 3H003 AA02 AC03 AD03 CB08                 3J044 AA02 AA18 BA06 CB09 CB18                       DA07 EA05

Claims (13)

[Claims] 1. A reciprocating compressor that compresses gas by a piston that reciprocates in a cylinder, wherein the piston is a distance ring attached to a piston rod, and a piston ring formed on the outer circumference of the distance ring. A plurality of divided piston rings mounted in the mounting groove and a tension ring for urging the piston ring from the inside to the outside are provided, and the piston ring is arranged in an outward direction with respect to the piston ring mounting groove of the distance ring. A reciprocating compressor, which is fitted so as to come off. 2. The reciprocating compressor according to claim 1, wherein the piston ring is in contact with the inner wall surface of the piston ring mounting groove of the distance ring via a straight surface. 3. The reciprocating compressor according to claim 1, further comprising a plurality of the distance rings. 4. The reciprocating compressor according to claim 3, wherein the piston ring mounting groove of the distance ring is a notched groove formed from the outer peripheral surface of the distance ring to one of the disc surfaces. 5. The reciprocating compressor according to claim 4, wherein the distance ring is attached so that the tip end side and the root side are opposite in the longitudinal direction of the piston rod. 6. The reciprocating compressor according to claim 1, wherein a width dimension of the tension ring is set smaller than a width dimension of the piston ring. 7. The reciprocating compressor according to claim 6, wherein the tension ring is provided at a central portion in a width dimension of the piston ring. 8. The piston ring is configured to contain a fluororesin and molybdenum disulfide.
The reciprocating compressor according to any one of 1. 9. The reciprocating compressor according to claim 1, wherein the tension ring is mainly composed of a fluororesin. 10. A piston used in the reciprocating compressor according to any one of claims 1 to 9. 11. A piston ring used in the reciprocating compressor according to any one of claims 1 to 9. 12. A tension ring used in the reciprocating compressor according to claim 1. 13. A distance ring used in the reciprocating compressor according to any one of claims 1 to 9.