JPH1137583A - Gas compressor/expander - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong the service life of a gas compressor/expander by sustaining the lubricity of a rod seal member over a long term thereby suppressing the abrasion of a sealing member as much as possible. SOLUTION: The gas compressor/expander comprises a piston working chamber 21, a piston driving chamber, a rod sealing unit 9 for passing a piston rod 22 while preventing lubricant in the piston driving chamber from intruding into the piston working chamber 21, wherein the rod sealing unit 9 comprises a sealing member 91 exhibiting higher sealing performance for the lubricant flowing from the piston driving chamber toward the piston working chamber 21 than for the lubricant flowing reversely, and means 92 for coating the piston rod 22 with a semi-solid or solid lubricant 93 disposed on the piston working chamber 21 of the sealing member 91.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas compression / expansion machine such as a Stirling engine used for generating power and a Stirling refrigerator used for generating low temperature, and more particularly to a rod for preventing oil from entering a working space. The present invention relates to a gas compression / expansion machine provided with a sealing device.

[0002]

2. Description of the Related Art In recent years, there has been an urgent need to develop techniques for preserving various samples and various materials at extremely low temperatures in advanced technology fields such as the field of biotechnology and the field of electronic devices. In particular, gas compression / expansion machines such as Stirling refrigerators are attracting attention as means for achieving the extremely low temperatures, and are about to be widely used in various infrared sensors, freezers for cooling and biomedical devices such as superconducting devices, and freezers.

[0003] In this gas compression and expansion machine,
A piston or a displacer for compressing and / or expanding the working gas is configured to reciprocate in the cylinder via a piston rod, into which oil enters the piston working chamber from the piston driving chamber. An oil seal device is provided in order to prevent this from happening.

FIG. 5 shows a conventional oil seal device mounted on a piston rod. In the figure, 101 indicates a cylinder such as an expansion cylinder or a compression cylinder, 102 indicates a piston that reciprocates in the cylinder 101, 103 indicates a piston rod, 104 indicates a cross guide, and 1
Reference numeral 05 denotes a connecting rod connecting the cross guide 104 to a crankshaft accommodated in a crank chamber (not shown).
Reference numeral 06 denotes a guide unit for guiding the cross guide 104. At the upper end of the guide portion 106, a rod seal portion 107 that surrounds the piston rod 103 and that prevents lubricating oil in the crank chamber from entering the rear side of the piston 102 is mounted.

[0005] As the rod seal portion 107, a lip-type seal member is used which has a higher sealing property against a flow in the direction from the crank chamber to the back side of the piston 102 than a reverse flow. . This lip-type seal member is superior in one-way sealability as compared with a resin-type seal member such as a slipper seal having no seal directionality, and is widely used in hydraulic mechanisms and the like.

[0006]

However, unlike one in which one of the sealing members is always in contact with the lubricating oil, such as a hydraulic mechanism, a gas compression expander is designed to prevent oil from entering the working space as much as possible. However, the lubricating oil filled in the crank chamber is not actively supplied to the seal portion, and there is a problem that the wear of the seal member is severe.

For this reason, measures such as applying a lubricant such as grease to the contact portion (seal portion) of the seal member in advance have been taken, but the lubricant applied to the seal portion causes the piston rod 103 to reciprocate. Accordingly, there is a problem that the device life is shortened due to the wear of the seal member.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas compression / expansion device provided with a sealing member having a higher sealing performance against a flow in a direction from a piston drive chamber to a piston working chamber than a reverse flow. The purpose of the present invention is to extend the life of the device by maintaining the lubricating properties of the seal member and minimizing the wear of the seal member.

[0009]

According to the present invention, there is provided a gas compression / expansion machine having a piston working chamber having a piston or displacer reciprocating in a cylinder, and a piston drive mechanism for reciprocating the piston or displacer via a piston rod. And a rod seal device that penetrates a piston rod and prevents lubricating oil in the piston drive chamber from entering the piston working chamber.
Wherein the rod sealing device comprises: a sealing member having a higher sealing property with respect to a flow in a direction from the piston drive chamber toward the piston working chamber than a sealing property with respect to the opposite flow; and the piston working chamber of the seal member. And a lubricant applying means for applying a semi-solid or solid lubricant to the piston rod.

[0010] By using this configuration, the reciprocating motion of the piston rod lubricates the contact portion (seal portion) of the seal member having the directionality of the seal with the piston rod on the piston working chamber side and the piston drive chamber side. It is possible to maintain the performance for a long period of time and to minimize the wear of the seal member to extend the life of the device.

Preferably, the lubricant applying means includes: a lubricant storage container filled with a semi-solid or solid lubricant; and a part of a peripheral surface of the lubricant storage container having a piston rod and the inside of the lubricant storage container. A ball member rotatably supported in a state of contact with the lubricant, and by rotating the ball member with reciprocation of the piston rod, the lubricant in the lubricant container is transferred to the piston rod. It is good also as composition which applies.

With this configuration, a constant amount of lubricant is applied from the ball member to the piston rod over a long period of time as the piston rod reciprocates. Further, the seal member may be constituted by a lip-shaped seal member. With this configuration, it is possible to achieve high sealing performance against the flow in the direction from the piston drive chamber to the piston working chamber.

Further, a gas seal member may be disposed on the piston working chamber side of the rod seal device. By using this configuration, the lubricating means can maintain the lubricating property of the seal portion of the gas seal member for a long period of time, minimize the wear thereof, and extend the life of the device.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a gas compression expander to which a rod seal device according to an embodiment of the present invention is applied. In the description of the present embodiment, a case of a displacer type Stirling refrigerating apparatus as a gas compression and expansion machine will be described as an example.

An expansion cylinder 2 and a compression cylinder 3 are attached to the main housing 1 at an angle difference of 90 degrees. A displacer 6 built in the expansion cylinder 2 and a compression piston 7 built in the compression cylinder 3 are: It is connected to a common crank mechanism (piston drive mechanism) 5 and is driven to reciprocate with a certain phase difference from each other.

The displacer 6 is filled with a regenerator 14 made of, for example, a sintered metal, and the working gas flowing from one opening of the displacer 6 is filled with the regenerator 14.
In the process of passing through the inside of the
Heat exchange with the cold storage material 14 is performed.

The displacer 6 also has a function as a regenerative heat exchanger, and its heat exchange performance greatly affects the coefficient of performance of the refrigeration system. The expansion cylinder 2 and the compression cylinder 3 are separated from a crank chamber (piston drive chamber) 12 by rod seal devices 8 and 9 described later, respectively. Are communicated with each other by a gas flow path 4. Thus, the compression space 13 formed in the compression cylinder 3 and the expansion space 11 formed in the expansion cylinder 2 are communicated by the gas flow path 4 via the cold storage material 14. On the other hand, oil 10 is injected into the crank chamber 12.

With the above configuration, the compression piston 7 and the displacer 6 reciprocate with a certain phase difference by the crank mechanism 5 driven by the rotation of the drive motor. First, the compression piston 7 moves to compress the working gas such as helium filling the inside of the apparatus main body, and the compressed and heated working gas is radiated by the radiation fins (not shown).
Next, after the working gas is cooled by the lowering of the displacer 6, the expansion space 1 serving as the working space of the expansion cylinder 2 is cooled.
It is led to 1. Thereafter, an expansion step is performed in which the working gas in the apparatus main body expands due to the movement of the compression piston 7, and the working gas is cooled to a low temperature by the expansion of the working gas, thereby cooling a cooler (not shown) via the cold head 15. Subsequently, the working gas is warmed by the rise of the displacer 6, and then the compression space 13 which is the working space of the compression cylinder 3 is heated.
Led to.

The above steps are sequentially repeated, and when the working gas in the expansion space 11 expands, the cooler is cooled to gradually reach the freezing temperature. Next, the structure of the rod seal device of the present invention will be described with reference to FIG. FIG. 2 is a cross-sectional view showing a part of the rod seal device 9 in the Stirling refrigerating device described above. Although only the specific configuration of the rod seal device 9 shown in FIG. 1 will be described below in detail, the same applies to the specific configuration of the rod seal device 8.

In the drawing, reference numeral 21 denotes the above-mentioned compression piston 7
, A piston rod 22 having one end connected to the compression piston 7, 23 a piston rod 2
A cross guide 24 connected to the other end of the connecting rod 2; a connecting rod 24 connected to a crankshaft housed in the crank chamber 12;
Reference numeral 25 denotes a guide unit for guiding the cross guide 23. A rod seal device 9 is mounted on the upper end of the guide portion 25 to surround the piston rod 22 and prevent the lubricating oil in the crank chamber 12 from entering the rear side of the compression piston 7.

This rod seal device 9 is used for the crank chamber 1.
A seal member 91 of a lip-type seal, which has a higher sealing property against the flow in the direction from 2 to the piston working chamber 21 than the reverse flow, and is disposed on the piston working chamber 21 side of the sealing member 91, And a lubricant applying means 92 for applying a lubricant 93 to the rod 22.

The lubricant applying means 92 includes a lubricant container 920 filled with semi-solid or solid grease as the lubricant 93, and a part of the peripheral surface of the
And a ball member 921 rotatably supported in contact with the grease 93 in the lubricant container 920.

A weight member 922 for urging the filled grease 93 toward the ball member 921 is provided in the lubricant storage container 920, and the grease 93 is always fed into the ball member 921. The structure is In this embodiment, four ball members 9 are used.
21 are arranged at equal intervals on the outer circumference of the piston rod 22,
The ball member 921 rotates with the reciprocation of the piston rod 22, and the grease 93 is applied to the piston rod 22 via a contact portion with the ball member 921.

With this configuration, as shown in FIG. 3, the grease 93 applied to the piston rod 22 from the seal lubricant applying means 92 is lowered by the piston rod 22 (downward in the drawing). 22
Is applied to the contact portion, that is, the seal portion.

The seal member 91 is connected to the crank chamber 12.
Is arranged such that the sealing performance against the flow in the direction from the piston working chamber 21 to the piston working chamber 21 is higher than the sealing performance against the opposite flow, so that the lubricant applying means 92 is disposed on the piston working chamber 21 side. As a result, with the reciprocating motion of the piston rod 22, not only the seal portion of the seal member 91 on the piston working chamber 21 side but also the seal portion on the crank chamber 12 side is maintained in a state where the grease 93 is appropriately applied. . Thereby, the wear of the seal member 91 can be suppressed as much as possible, and the life of the device can be prolonged.

Next, as shown in FIG. 4, when a gas seal member 41 for preventing the working gas from flowing to the crank chamber 12 is provided on the piston working chamber 21 side of the rod seal device 9, As the piston rod 22 reciprocates, the grease 93 is appropriately applied to the seal portion of the gas seal member 41 by the lubricant applying means 92, and wear of the gas seal member 41 can be suppressed as much as possible. still,
In this embodiment, a resin-type sealing member such as a T-ring having no directionality of the seal is used as the gas seal member 41, but a lip-type seal having directionality in the sealing property is used similarly to the seal member 91. It does not matter. However, in this case, the seal member 91 is disposed in the opposite direction, that is, the sealing property against the flow in the direction from the piston working chamber 21 to the piston driving chamber 12 is higher than the sealing property against the reverse flow. Need to be placed.

The description of the above embodiment is for the purpose of describing the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof.
Further, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.

For example, in the above-described embodiment, the case where a lip-type seal member is used as the seal member 91 has been described. However, the present invention is not limited to the lip-type seal member as long as it has the above-described directionality. .

[0029]

As described above, according to the present invention, as a rod seal device for preventing oil from entering into the working space, sealing performance against flow in the direction from the piston driving chamber to the piston working chamber is obtained. In a gas compression / expansion machine provided with a sealing member having a higher sealing performance against the reverse flow, the lubrication of the sealing member is maintained for a long period of time, and the wear of the sealing member is suppressed as much as possible to extend the life of the device. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a displacer type Stirling refrigerating apparatus to which the present invention is applied.

FIG. 2 is a sectional view of a main part of the rod seal device according to the embodiment of the present invention.

FIG. 3 is a perspective view of a main part for explaining the operation of the rod seal device.

FIG. 4 is a sectional view of a main part of a rod seal device according to another embodiment of the present invention.

FIG. 5 is a sectional view of a conventional rod sealing device.

[Explanation of symbols]

 2 Expansion cylinder 3 Compression cylinder 4 Gas flow path 5 Crank mechanism (piston drive mechanism) 6 Displacer 7 Compression piston 8, 9 Rod seal device 11 Expansion space 12 Crank chamber (piston drive chamber) 13 Compression space 21 Piston working chamber 22 Piston rod 23 Cross Guide 24 Connecting Rod 41 Gas Seal Member 91 Seal Member 92 Lubricant Applying Unit 93 Grease (Lubricant) 920 Lubricant Storage Container 921 Ball Member 922 Weight Member

Claims (4)

[Claims] 1. A gas compression / expansion device for compressing and / or expanding a working gas, comprising: a piston working chamber having a piston or displacer reciprocating in a cylinder; and a piston for reciprocating the piston or displacer via a piston rod. A piston drive chamber accommodating a drive mechanism; and a rod seal device that penetrates a piston rod and prevents lubricating oil in the piston drive chamber from entering the piston working chamber. A sealing member having a higher sealing property against the flow in the direction from the driving chamber to the piston working chamber than the sealing property against the opposite flow, and a seal member disposed on the piston working chamber side of the sealing member, and a semi-solid Or a lubricant applying means for applying a solid lubricant. Gas compression and expansion machine for. 2. The lubricant supply means includes: a lubricant storage container filled with a semi-solid or solid lubricant; a part of a peripheral surface of the lubricant storage container being a piston rod and a lubricant in the lubricant storage container. A ball member rotatably supported in a state of contact with the piston rod, and applying the lubricant in the lubricant container to the piston rod by rotation of the ball member accompanying reciprocation of the piston rod. The gas compression / expansion machine according to claim 1, wherein: 3. The gas compression / expansion machine according to claim 1, wherein the seal member is a lip-type seal member. 4. The gas compression / expansion machine according to claim 1, wherein a gas seal member is arranged on the piston working chamber side of the rod seal device.