JP2823545B2 - Gas compression and expansion machine - Google Patents

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 seal for preventing oil from entering a working space. The present invention relates to a gas compression / expansion machine provided with a 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 temperature, and are going to be widely used for cooling, biomedical freezers, freezers, and the like for various infrared sensors, superconducting devices, and the like.

[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. 4 shows a conventional oil seal device attached to 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 seal-type seal member is used which has higher sealing performance against flow in the direction from the crank chamber to the rear side of the piston 102 than the reverse flow. I have. This lip seal-type seal member has better one-way sealability than 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 lip portion of the seal member in advance are taken, but the lubricant applied to the lip portion is
3 is gradually removed with the reciprocation, and as a result, there is still a problem that the life of the device is caused by wear of the seal member.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas provided with a seal member which is disposed on a piston working chamber side and has a higher sealing property against a flow in a direction from a piston driving chamber toward a piston working chamber than a sealing property against a reverse flow. It is an object of the present invention to extend the life of a compression / expansion device by maintaining the lubrication of a seal member for a long period of time and minimizing wear of the seal member.

[0009]

SUMMARY OF THE INVENTION The present invention provides a gas compression and expansion machine for compressing and / or expanding a working gas, comprising: a piston working chamber having a piston or a displacer reciprocating in a cylinder; A piston drive chamber that houses a piston drive mechanism that reciprocates via a piston rod, and a rod seal device that penetrates the piston rod and prevents lubricating oil in the piston drive chamber from entering the piston working chamber. The rod seal device is provided with a first seal member arranged on the piston drive chamber side and a seal property against a flow from the piston drive chamber to the piston work chamber arranged on the piston working chamber side. A second seal member having a higher sealing performance against the reverse flow, and a second seal member disposed between the first and second seal members. Characterized by comprising a seal lubricant holding portion is, the.

[0010] By using this configuration, the grease applied to the piston rod from the seal lubricant holding portion is:
The stagnation between the first seal member and the second seal member is always maintained, so that the grease is appropriately applied to the lip portions of the first seal member and the second seal member, and wear of the seal member is minimized. You can do it.

[0011] Preferably, the first seal member is formed of a seal member having a higher sealing property against a flow in a direction from the piston working chamber to the piston driving chamber than a reverse flow.

By using this configuration, the grease applied to the piston rod from the seal lubricant holding portion is
Flow through the first seal member to the piston drive chamber side is reliably prevented.

[0013]

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 body 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: Connected to a common crank mechanism (piston drive mechanism) 5
Reciprocating drive is performed with the phase shifted by 0 degrees.

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 16. Next, the working gas is cooled by the lowering of the displacer 6 and then guided to the expansion space 11 which is the working space of the expansion cylinder 2. Thereafter, an expansion step is performed in which the working gas in the apparatus 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.
To cool a not-shown cooler or the like. Subsequently, the working gas is warmed by the rise of the displacer 6 and then guided to the compression space 13 which is the working space of the compression cylinder 3.

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 figure, reference numeral 21 denotes the above-described compression piston 7
, A piston working chamber 22 having one end connected to a compression piston 21 and a piston rod 23
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.

The rod seal device 9 is used for the crank chamber 1
A first seal member 91 disposed on the second side, a second seal member 92 disposed on the piston working chamber 21 side,
And a seal lubricant holding portion 93 disposed between the second seal members 91 and 92.

The first seal member 91 has a direction opposite to that of the seal member 107 shown in FIG.
That is, a lip seal-type sealing member that exhibits particularly excellent sealing performance with respect to the flow in the direction from the back side of the compression piston 7 to the crank chamber 12 is mounted. Also, the second
Of the first seal member 9 as in the prior art.
A lip seal-type seal member having a direction opposite to that of 1, that is, exhibiting particularly excellent sealing performance with respect to the flow in the direction from the crank chamber 12 to the back side of the compression piston 7 is mounted. Further, between the first seal member 91 and the second seal member 92, there is provided a concave portion 94 that faces the piston rod 22 and holds the grease 95. A part 93 is provided.

With this configuration, the seal lubricant holding portion 93 is provided.
The grease 95 applied to the piston rod 22 from
The state where the grease 95 is appropriately applied to the lip portions of the first seal member 91 and the second seal member 92 is maintained, and the seal member always stays between the first seal member 91 and the second seal member 92. Wear can be suppressed as much as possible.

Further, the grease 95 applied to the piston rod 22 is prevented from flowing through the first seal member 91 to the crank chamber 12 side. The description of the above embodiments 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, as shown in FIG. 3, as the first seal member shown in FIG. 2, a slipper seal or the like having no direction of the seal may be used instead of the lip seal type seal member 91 having the above-described direction. Almost the same effect can be obtained by using the resin-type sealing member 91b. However, in this case, the sealing performance against the flow in the direction from the back side of the compression piston 7 to the crank chamber 12 is slightly inferior to the sealing member 91 having the above-described directivity. 3
Reference numeral 1 denotes an O-ring for urging the seal member 91b against the piston rod 22.

In the description of the above embodiment, the case where a lip seal type seal member is used as the seal member has been described. However, the lip seal type seal member is not limited as long as it has the above-described directionality. Absent.

[0026]

As described above, according to the present invention, the sealing performance with respect to the flow in the direction from the piston driving chamber to the piston working chamber disposed on the piston working chamber side is higher than the sealing performance with respect to the opposite flow. In a gas compression / expansion machine provided with a seal member, it is possible to maintain the lubricity of the seal member for a long period of time, minimize wear of the seal member, and extend the life of the device.

[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 cross-sectional view of a main part of a rod seal device diagram according to another embodiment of the present invention.

FIG. 4 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 91 First Seal Member 92 Second Seal Member 93 Seal Lubricant Holder

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takafumi Nakayama 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) F25B 9 / 14 510

Claims (2)

(57) [Claims] In a gas compression / expansion machine for compressing and / or expanding a working gas, a piston working chamber having a piston or displacer reciprocating in a cylinder, and the piston or displacer reciprocating via a piston rod. A piston drive chamber that houses a piston drive mechanism, and a rod seal device that penetrates the piston rod and prevents lubricating oil in the piston drive chamber from entering the piston working chamber. A first seal member arranged on the piston drive chamber side, and a first seal member arranged on the piston working chamber side;
A second seal member having a higher sealing property with respect to the flow in the direction from the piston driving chamber to the piston working chamber than the sealing property with respect to the opposite flow, and the first sealing member and the second sealing member. A gas compression / expansion machine comprising: a seal lubrication material holding unit. 2. The gas according to claim 1, wherein the first seal member has a higher sealing property against a flow in a direction from the piston working chamber to the piston driving chamber than a sealing property against a reverse flow. Compression and expansion machine.