JP2828947B2 - Oil seal device for gas compression / expansion machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil seal device for a gas compressor / expander which compresses or expands gas by reciprocating a piston.

[0002]

2. Description of the Related Art Conventionally, gas compressors / expanders have been used in Stirling refrigerators, Stirling engines, reciprocating compressors and the like.

FIG. 5 shows a schematic configuration of such a gas compression / expansion machine. The gas compression / expansion machine 100 includes an operating unit 1
10 and a drive unit 120, which are separated by a partition unit 130. The operating section 110 is provided with a piston 111 provided to be able to reciprocate in the operating section 110, and the crank mechanism 121 provided in the driving section 120 is provided with a cross guide 123 via a connecting rod 122. It is connected.

The piston 111 and the cross guide 12
Numeral 3 is connected by a rod 140 that passes through the partition 130, and the rotational movement of the crank mechanism 121 is converted into a reciprocating movement and transmitted to the piston 111. Thus, the working gas in the working unit 110 is compressed or expanded by the reciprocating motion of the piston 111.

[0005] The crank mechanism 121 is lubricated with oil 124. However, if the oil 124 enters the operating part 110 and mixes with the working gas, it deteriorates the compression efficiency and the like. For this reason, the partition member 130 is provided with a seal material 131 that is inserted into the rod 140, and rubs against the rod 140 so that the oil 1 adhering to the rod 140 is removed.
24 is wiped off.

FIG. 6 is a sectional view of a portion where the sealing material 131 is provided. The seal material 131 is used for the seal storage unit 1.
32, and the rod 1
It is biased to the 40 side. As described above, the sealing material 13
The sealing effect of the sealing material 131 and the rod 140
It is achieved by wiping off the oil 124 adhered by the rubbing of the sealing material 131. Therefore, in order to sufficiently wipe off the oil 124, it is necessary to urge the sealing material 131 with a strong backup force.

[0007] However, such a method of removing the oil 124 has a problem that the sealing material 131 is worn out when used for a long time, and the sealing effect is reduced.

Further, when the cross guide 123 reaches the top dead center, the cross guide 123 is substantially in contact with the partitioning portion 130.
The oil 124 adhering to the seal member 131 escapes between the seal member 131 and the rod 140.

Further, the oil 124 attached to the reciprocating cross guide 123 is removed by the sealing material 131 due to the inertial force.
Or the oil 124 accumulates between the cross guide 123 and the partition 130 due to long-time operation, and the oil 124 is kicked off by the cross guide 123 toward the seal material 131.

When the above-mentioned situation occurs, the oil 124 is gradually sent to the operating part 110 side by the reciprocating movement of the rod 140, and finally enters the operating part 110 and mixes with the working gas, so that the gas compression / expansion device is used. Performance will be reduced. Thus, the device is rendered unusable. That is, the life of the device is determined by these factors.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned problems and prevents oil from being mixed into the working gas, thereby providing a highly reliable and long-life gas compressor / expander. It is an object to provide an oil seal device.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an operating portion for accommodating a piston to which one end of a rod is connected in a reciprocating manner, and a cross guide connected to the other end of the rod. An oil seal device of a gas compression / expansion machine having a drive section for housing a drive mechanism for reciprocating the actuator, and a partition section through which the rod is inserted to partition the operating section and the drive section. The intermediate portion is formed so as to include the rod, the length in the rod axial direction is formed longer than the stroke length of the rod, and the size in the rod radial direction is formed larger than the thickness of the oil adhering to the rod. And a pressure fluctuation reducing means for mitigating a fluctuation in the pressure of the intermediate chamber due to a pressure fluctuation in the working chamber.

The pressure fluctuation reducing means may include a buffer chamber communicating with the intermediate chamber or a communication unit including an oil filter for communicating the intermediate chamber with the drive unit and removing oil contained in the atmosphere of the drive unit. It is characterized by being any one of the parts.

Further, a pressure seal member for shutting off the pressure between the operating section and the intermediate chamber is provided in the partition section on the operating section side.

The dimension of the intermediate chamber in the direction of the rod diameter refers to the dimension from the surface of the rod, and the thickness of the oil means that if the thickness of the oil adhering to the rod has a distribution, It means the maximum thickness.

[0016]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a Stirling refrigerator when the oil seal device according to the present invention is applied to a displacer type Stirling refrigerator. In the following description, upper, lower, left, and right directions may be defined. However, these directions generally indicate the directions in FIG. 1, and in other cases, the directions are described. For the reference numerals, for example, the cross guide 42
When (42a, 42b) is described, number 42 is number 4
Each of 2a and 42b is a general number.

The Stirling refrigerator 10 includes a compression section (operating section) 20 having a compression piston 21 and a displacer 3.
1 and a drive unit 40 having a crank mechanism 41. The compression unit 20 and the displacer unit 30 are communicated by a gas flow path 60.

The compression piston 21 has a rod 49a.
And the rod 49a is connected to the cross guide 42a of the drive unit 40 through the partition 50a.
Similarly, the displacer 31 is connected to the rod 49b,
The rod 49b is inserted through the partition 50b and
Is connected to the cross guide 42b.

The displacer 31 is provided with a regenerator 33, and the regenerator 33 is made of a material having a large specific heat, for example, a regenerator made of a wire mesh or sphere of copper, lead, or stainless steel.

The cross guide 42 (42a, 42b)
The cross guides 43 are guided by cross guides 43 (43a, 43b), and the cross guides 42 are connected by connecting rods 44.
It is connected to the crank mechanism 41 via (44a, 44b). The driving force from the crank mechanism 41 provided in the driving section 40 is transmitted to the cross guide 42 via the connecting rod 44. At this time, the two connecting rods 44a and 44b receive the driving force from the crank mechanism 41 at the same point of action. As a result, the compression piston 21 and the displacer 31 move synchronously.

A cross guide space 45 is provided between the cross guide 42 and the partition portion 50 in order to avoid these contacts.
(45a, 45b) are provided. As a result, the contact between the cross guide 42a reaching the left end dead center and the partition 50a and the cross guide 42b reaching the top dead center and the partition 50 are made.
b is prevented from contacting.

The dimension of the cross guide space 45 in the axial direction of the rod 49 is set to be larger than the thickness of the oil 46 attached to the surface of the cross guide 42 to which the rod 49 is connected.

Since the displacer section 30 is provided upright, the surface of the cross guide 42b to which the rod 49b is connected can be approximated to a substantially horizontal plane, whereby the oil 46 adhering to the surface can be approximated. Can be regarded as uniform. However, since the compression section 20 is disposed in the horizontal direction, the oil 46 is urged by the cross guide 4 due to gravity.
2a is gathered on the lower side, and the adhering oil 4
A distribution occurs in the thickness of No. 6. Accordingly, in such a case, the thickest portion of the oil 46 is the thickness of the oil 46.

A crank mechanism 41 is provided below the drive section 40.
An oil tank 47 for storing oil 46 for lubricating the oil is provided, and the cross guide space 45a on the compression section 20 side and the oil tank 47 are communicated by an oil return path 48a. The side surface of the cross guide 42b on the side of the displacer 30 is partially notched to form an oil return gap 48b. A dotted area in FIG. 2 indicates a notched area.

The oil return path 4 is connected to the cross guide guide 43a.
8a, and an oil return gap 48b is provided in the cross guide 42b.
Is provided for the following reason. That is, in the present embodiment, since the displacer section 30 is disposed in the upright state, the oil 46 in the cross guide space 45b can be dropped from the oil return gap 48b by gravity and returned to the oil tank 47. The arrows in FIG. 2 indicate the flow of the oil dropped in this way.

On the other hand, since the compression section 20 is disposed in the horizontal direction, the oil 46 in the cross guide space 45a cannot return to the oil tank 47 due to gravity. For this reason, an oil return path 48a passing through the inside of the cross guide guide 43a is provided so that the oil 46 accumulated in the cross guide space 45a is returned to the oil tank 47.

The shape of the oil return gap is not limited to the one shown in FIG. 2, but may be a groove formed on the side surface of the cross guide 42b, or a groove formed on the cross guide guide portion. It may be.

A rod 49 (49) is provided inside the partition 50.
a, 49b) to include the intermediate chamber 51 (51a, 51b).
b), and a seal member 52 (52a, 52b) that is inserted into the rod 49 and rubs against the rod 49 is provided. And the sealing material 52 made of a member such as PTFE,
The oil 46 adhering to the rod 49 is wiped off by sliding on the rod 49.

The intermediate chamber 51 has a communication passage 56 (56a, 5a).
6b) and the buff chamber 57 (57a, 57b)
b) is provided, and a pressure sealing material 5 is provided in a partition 50 between the intermediate chamber 51 and the compression section 20 and the displacer section 30.
8 (58a, 58b) are provided.

The intermediate chamber 51 has a dimension in the axial direction of the rod 49 longer than the stroke length of the rod 49.
Nine radial dimensions are formed larger than the thickness of the oil 46 attached to the rod 49 located in the intermediate chamber 51.

The above dimensions are set in consideration of the installation direction of the compression section 20 and the displacer section 30, the stroke length of the rod 49, the diameter and material of the rod 49, the sealing force of the sealing material 52, and the like. is there.

The Stirling refrigerator 10 of this embodiment is configured as described above, and a driving force is transmitted from the crank mechanism 41 to the compression piston 21 and the displacer 31 by rotation of a drive motor (not shown).

At this time, since the compression piston 21 and the displacer 31 are disposed orthogonally to each other, the compression unit 2
When the 0-side connecting rod 44a is substantially horizontal, the compression piston 21 hardly moves, but the displacer 31 moves the most. Conversely, when the connecting rod 44b on the displacer section 30 side is substantially vertical, the displacer 31 hardly moves, but the compression piston 21 moves the most. Thus, the compression piston 21 and the displacer 31 are synchronously moved out of phase.

Next, the operation of the above-structured Stirling refrigerator 10 will be described. As described above, the compression piston 21
It should be noted that the phase of the compression process and the expansion process, which will be described later, cannot be strictly distinguished because the phases of the compression process and the displacer 31 are shifted.

When the compression piston 21 moves from the left end dead center to the right end dead center, the working gas in the working space 22 of the compression section 20 is isothermally compressed by the compression piston 21.

During this time, the displacer 31 moves upward, and moves downward after reaching the top dead center. The working gas compressed due to the upward movement of the displacer 31 is sent to the displacer unit 30 through the gas flow path 60, and
When 1 moves downward, the working gas passes through the regenerator 33, radiates heat to the regenerator 33, and is sent to the expansion space 32.

As the displacer 31 reaches the bottom dead center, the compression piston 21 moves from the right end dead center to the left end dead center, and the working gas expands and cools down. Since the expansion process at this time is an isothermal expansion process, external heat is absorbed as much as the temperature is reduced by the expansion. That is, it can be cooled.

As the compression piston 21 approaches the left dead center, the displacer 31 starts to move upward, and the working gas passes through the displacer 31 and absorbs heat from the regenerator 33 to 1.
The cycle ends.

In the Stirling refrigerator 10 that performs the above-described cycle, when the oil 46 is mixed into the working gas, the cooling efficiency is reduced. That is, the oil 46 attached to the cross guide 42 enters the cross guide space 45 by the reciprocating motion of the cross guide 42, and gradually advances between the partition portion 50 and the rod 49 with the reciprocating motion of the rod 49. Eventually, it reaches the compression section 20 or the displacer section 30 and mixes into the working gas.

Therefore, the oil 46 attached to the rod 49
Is wiped off by the sealing material 52 rubbing against the rod 49. However, with such a mechanical removal method,
In order to remove the oil 46, it is necessary to urge the sealing member 52 against the rod 49 with a strong force, and there is a problem that the sealing member 52 is significantly worn due to long-time use and the sealing force is reduced.

In order to solve such a problem, the dimension of the intermediate chamber 51 in the axial direction of the rod 49 is adjusted so that the oil 46 adhering to the rod 49 is reduced by the side wall 53 (5) of the intermediate chamber 51.
3a, 53b), that is, longer than the stroke length of the rod 49. The size of the rod 49 in the radial direction is determined by the amount of oil 4 remaining on the rod 49.
6 is set so as not to contact the cylindrical surface 54 (54a, 54b) of the intermediate chamber 51. Thereby, even if the oil 46 is not completely removed, the tip of the oil 46 (the point closest to the compression unit side and the displacer unit side) does not reach the side wall 53 of the partition unit 50. Therefore,
It is not sent to the compression section 20 and the displacer section 30 through the side wall 53.

However, the oil 46
Is contained, the atmosphere can enter the operating section (the compression section 20 or the displacer section 30), and it is necessary to prevent this. Working parts 20 and 30 in such an atmosphere
Intrusion occurs because the pressure in the intermediate chamber 51 temporarily becomes higher than the pressure in the operation units 20 and 30. FIG. 3 shows pressure fluctuations in the intermediate chamber 51, the actuating sections 20, 30 and the drive chamber 40. FIG. 3A shows a case where no buffer chamber is provided.
(B) shows a case where a buffer chamber is provided. In the operating parts 20 and 30, the piston 21 or the displacer 31
Since the working gas is compressed / expanded, the working portion 2
The pressure in 0,30 fluctuates periodically.

Ideally, the intermediate chamber 51, the operating parts 20, 30
The drive unit 40 and the drive unit 40 form independent systems, so that the pressures in the intermediate chamber 51 and the drive unit 40 are not affected by pressure fluctuations in the operation units 20 and 30. However, in reality, the intermediate chamber 51 and the operating units 20 and 30, and the intermediate chamber 51 and the driving unit 40
Are secured by a very narrow clearance between the rod 49 and the partition 50, so that they are not completely independent systems. When the clearance is made smaller, the conductance of the gas passing through the clearance becomes smaller, so that the pressure fluctuation width of the intermediate chamber 51 can be made smaller than the pressure fluctuation width of the operating portions 20 and 30.

However, if the clearance is too small, a large driving force is required to drive the rod 49, and the friction between the rod 49 and the partition 50 becomes large, so that the clearance cannot be reduced without limit.

Further, because of the small conductance, the cycle of the pressure fluctuation of the intermediate chamber 51 has the same cycle as the cycle of the pressure fluctuation of the operating portions 20 and 30, but the phase is shifted. For the above reasons, there occurs a time period in which the pressure in the intermediate chamber 51 is temporarily higher than the pressure in the operating units 20 and 30,
In this time zone, the gas containing the oil 46 in the intermediate chamber 51 flows toward the operation units 20 and 30.

As described above, a gas flow always flows from the operating portions 20 and 30 to the intermediate chamber 51 and vice versa, but a finite time is required for the gas to move, and the time is the conductance. And the intermediate chamber 51 and the operating part 2
It depends on the pressure difference between 0 and 30.

Therefore, if the pressure in the intermediate chamber 51 is reduced, the gas containing the oil 46 is transferred from the intermediate chamber 51 to the operating section 2.
Even if the gas moves toward 0,30, the gas remains
It takes a long time to reach 30 and the gas is
Before reaching the working part 30, the pressure on the side of the working parts 20, 30 becomes higher than the pressure in the intermediate chamber 51, so that the gas containing the oil 46 cannot reach the working parts 20, 30 after all.

Therefore, in the present invention, the clearance is set to a realistic size from the viewpoint of increasing the size of the device by reducing the clearance and effectively utilizing the driving force, and the partition portion is set to reduce the conductance only. 50
The pressure seal material 58 (58a, 5)
8b). Further, a buffer chamber having a large space capacity is provided in order to reduce the pressure of the intermediate chamber 51 and the pressure fluctuation width.

With such a configuration, the operating section 20,
Even if the working gas flows in from the 30 side and the pressure in the intermediate chamber 51 fluctuates, the fluctuation in the pressure is absorbed by the buffer chamber, so that the pressure fluctuation in the intermediate chamber 51 is reduced. Therefore, even if the pressure in the intermediate chamber 51 temporarily becomes higher than the pressure in the operation units 20 and 30, the gas including the oil 46 does not flow into the operation units 20 and 30 from the intermediate chamber 51. Further, since the pressure value of the intermediate chamber 51 can be reduced by the buffer chamber 57, the pressure in the space between the intermediate chamber 51 and the drive unit 40 can be maintained at substantially the same pressure. Therefore, from the driving unit 40 to the intermediate chamber 51, and to the operating unit 20,
It is possible to prevent the oil 46 from entering the 30.

In the above description, the buffer chamber is provided externally to the apparatus. However, the buffer chamber may be provided inside the apparatus, and the buffer chamber 57a on the compression section 20 side and the displacer section 3 may be provided.
Although the zero-side buffer chamber 57b is provided independently, the pressure fluctuation in each intermediate chamber 51 may be reduced by one buffer chamber.

Although an independent buffer chamber is provided, FIG.
As shown in (2), the intermediate chamber 51 and the drive unit 40 can be communicated with each other through the communication path 61, and the space in the drive unit 40 can be used as a buffer space. In this case, since the oil 46 is contained in the atmosphere of the drive unit 40, an oil filter 62 may be provided in the communication passage 61 to remove the oil 46. By adopting such a configuration, there is an advantage that the buffer chamber described above does not need to be separately provided and the apparatus can be downsized.

The compression section 20 and the displacer section 3
The communication paths 61 that communicate the 0 and the drive unit 40 may be provided independently of each other.

Furthermore, the case where the oil seal device is applied to a displacer type Stirling refrigerator has been described. However, the present invention is not limited to this, and an expansion piston type Stirling refrigerator, a Stirling engine, and a reciprocating compressor. Etc. may be used.

[0054]

According to the present invention, the influence on the pressure of the intermediate chamber due to the pressure fluctuation of the operating section is absorbed by the pressure reducing means, so that the pressure fluctuation of the intermediate chamber is suppressed and the pressure between the intermediate chamber and the drive section is reduced. The difference can be eliminated. Therefore, oil can be prevented from entering the intermediate chamber from the drive unit, and even if oil is contained in the atmosphere of the intermediate chamber, the atmosphere can be prevented from entering the working chamber and being mixed into the working gas, It has become possible to increase the reliability of the device and extend its life.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram when a gas compression / expansion machine having a buffer chamber according to the present invention is applied to a Stirling refrigerator.

FIG. 2 is a partial perspective view of a cross guide for explaining an oil return gap.

FIG. 3 is a diagram showing pressure fluctuations in an intermediate chamber, a working chamber, and a driving chamber.

FIG. 4 is a conceptual configuration diagram of a Stirling refrigerator in a case where a driving room is a buffer space.

FIG. 5 is a conceptual configuration diagram of a gas compression / expansion machine applied to a description of a conventional technique.

FIG. 6 is a partial cross-sectional view for explaining a sealing effect of a sealing material.

[Explanation of symbols]

 Reference Signs List 20 compression section (operating section) 21 piston 30 displacer section (operating section) 31 displacer 33 regenerator 40 drive section 42 (42a, 42b) cross guide 43 (43a, 43b) cross guide guide section 45 (45a, 45b) cross guide Space 46 Oil 48a Oil return path (oil return means) 48b Oil return gap (oil return means) 49 (49a, 49b) Rod 50 (50a, 50b) Partition part 51 (51a, 51b) Intermediate chamber 57 (57a, 57b) Intermediate chamber (pressure relief means) 58 (58a, 58b) Pressure seal material 61 (61a, 61b) Communication path (pressure relief means)

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F25B 9/14 510 F04B 39/00 104

Claims (4)

(57) [Claims] An actuator for reciprocating a piston connected to one end of a rod; a driving unit for accommodating a drive mechanism for reciprocating a cross guide connected to the other end of the rod; and the rod. An oil seal device of a gas compression / expansion machine having a partition part for inserting the operating part and the driving part, and including the rod inside the partition part, the dimension in the rod axial direction. Is formed longer than the stroke length of the rod, and the dimension in the radial direction of the rod is formed larger than the thickness of the oil adhering to the rod. An oil seal device for a gas compression / expansion machine, characterized by comprising means. 2. An oil seal device for a gas compression / expansion machine according to claim 1, wherein said pressure fluctuation reducing means is a buffer chamber communicating with said intermediate chamber. 3. The communication unit according to claim 1, wherein the pressure fluctuation reducing unit communicates with the intermediate chamber and the drive unit and includes an oil filter that removes oil contained in an atmosphere of the drive unit. Oil seal device for gas compression / expansion machines. 4. An oil seal device for a gas compression / expansion machine according to claim 1, wherein a pressure seal member for shutting off pressure between the operation section and the intermediate chamber is provided in the partition section on the operation section side.