JPH07151404A - Oil sealing device - Google Patents

Abstract

PURPOSE:To prevent lubrication oil from entering an operation part by providing an oil through-hole in a sealed space subject to oil sealing, increasing an interval of the oil sealing than a rod stroke, and setting an interval between the rod in the space and an interval wall to be a size outside a range where the entering lubrication oil rises owing to a capillary action. CONSTITUTION:A body casing 41 is constructed with a casing 42 and a casing 43 in which an oil through-hole 43e is provided. An interval A between two oil sealings 44 provided in the body casing 41 is set to be enough longer than a reciplocation stroke of a piston rod 27. Further, a space 46 formed with hollow parts 42c, 43c has its greater internal diameter to prevent the lubrication oil from rising owing to a capillary action even though a compression piston 13 is directed upward.

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 suitable for preventing entry of lubricating oil from a drive mechanism using lubricating oil such as a gas compression cycle engine into an operating mechanism such as a compressor.

[0002]

2. Description of the Related Art Generally, a gas compression cycle engine reciprocates an in-cylinder piston by a crank to compress or expand a gas. The gas compression engine smoothly operates the crank or the like for a long time. Therefore, lubricating oil is supplied to bearings such as cranks. On the other hand, in a gas compression cycle engine, when lubricating oil enters the gas compression / expansion portion, the efficiency decreases, and an oil seal is provided to prevent this.

Here, a principle of operation of a two-piston type Stirling refrigerator as an oil-sealed representative example will be described with reference to FIG.

The Stirling refrigerator 1 has a gas flow path 5 in which a gas compressor 2 and an expander 3 are interposed, and a regenerator 4 is interposed therebetween.
The radiator 6 and the radiator 7 are arranged on the gas compressor 2 side of the gas flow path 5 on the gas compressor 2 side and the inlet side of the regenerator 4 on the other hand, and the freezing take-out portion 8 is formed on the upper part of the expander 3. Further, a crank mechanism portion 9 is arranged behind the gas compressor 2 and below the expander 3.

The gas compressor 2 is for compressing a refrigerant gas having a cryogenic boiling point such as helium according to a predetermined cycle and supplying the compressed refrigerant gas to the expander 3. In the gas compressor 2, a compression cylinder is used. A compression space 11 for compressing a refrigerant gas is formed inside the main body 10, a compression piston 13 is slidably fitted in a compression cylinder 12, and the compression piston 13 reciprocates by the action of a crank mechanism section 9 described later. It is like this.

The expander 3 expands the compressed refrigerant gas supplied from the gas compressor 2 via the regenerator 4. The expander 3 has an expansion cylinder 15 inside the expander body 14 in the vertical direction. The expansion piston 16 is slidably fitted in the expansion cylinder 15 in the vertical direction, and the freezing generation section 17 is formed inside the expansion machine 3 as an expansion space in which a low temperature is generated.

The regenerator 4 is formed in a cylindrical shape between the inner circumference of the expander body 14 and the outer circumference of the expansion cylinder 15, and is a compressed refrigerant gas supplied to the expander 3 through the gas flow path 5. On the other hand, when the refrigerant gas expanded and cooled in the freezing generation section 17 is returned to the gas compressor 2 while cooling the refrigerant, the refrigerant is cooled and stores cold. Stainless steel, lead, and the like are used, and they are formed into a cylindrical shape having a large number of fine holes through which a refrigerant gas passes.

The gas flow path 5 is a pipe connecting the gas compressor 2 and the expander 3 so that the compressed refrigerant gas evenly passes through the regenerator 4 at the inlet side of the regenerator 4. The radiator 6 and the radiator 7 lower the compressed high-temperature refrigerant gas to near room temperature, and the radiator 6 has a large number of disk-shaped fins provided upright on the outside of the body of the compression cylinder body 10 for heat radiation. Bowl 7
Has a large number of circular fins standing on the outside of the body of the expander body 14. The freezing take-out unit 8 includes the freezing generation unit 17
The cold heat generated in 1 is taken out to a low temperature tank (not shown) or the like, and is covered with a plate-like body such as stainless steel on the upper portion of the expander body 14.

The crank mechanism section 9 reciprocates by the action of a crank motion using a drive motor (not shown) as a drive source for the compression piston 13 and the expansion piston 16. A crank chamber 22 having a guide portion 20 formed at the rear and a guide portion 21 below the expansion cylinder 15 is provided. Lubricating oil 23 is stored at the bottom of the crank chamber 22. A crank mechanism 24 is arranged inside. A connecting rod 25 extending from the crank mechanism 24 has a cross guide 26 slidably fitted in a guide receiver 20a of the guide portion 20, and a piston rod 27 communicating with the cross guide 26 is provided in the guide portion 20. The connecting rod 28 extending from the crank mechanism 24 is slidably fitted to the guide receiver 21a of the guide portion 21 while being connected to the rear portion of the compression piston 13 through the through hole 20b. Cross guide 29
Is connected to the rear part of the expansion piston 16 by penetrating the through hole 21b.

Here, the oil seal 33 is the crank chamber 2
The second lubricating oil 23 is provided to prevent the lubricating oil 23 from entering the space 32, and the oil seal 36 is provided to prevent the lubricating oil 23 in the crank chamber 22 from entering the space 35. In addition, 31 is the compression space 11 and the compression piston 1.
3 is a piston seal that disconnects the space 32 behind the space 3, and 34 is a piston seal that disconnects the space 35 behind the freezing generator 17 and the expansion piston 16.

First, when the crank mechanism 24 of the crank mechanism portion 9 is driven by the rotation of a drive motor (not shown), the compression piston 13 in the compression cylinder 12 of the gas compressor 2 moves to the compression space 11 side and the compression space 11 Refrigerant gas, such as helium or nitrogen, which is difficult to liquefy, is compressed. The compressed refrigerant gas is radiated to the outside by the radiator 6 provided on the outer periphery of the compression cylinder body 10 and cooled to near room temperature, passes through the gas flow path 5, and is further radiated by the radiator 7.
It is cooled by and flows into the regenerator 4.

The refrigerant gas that has flowed into the regenerator 4 is cooled by a material having a large specific heat, for example, a regenerator material such as copper or lead wire mesh or spheres, and the cooled refrigerant gas is used in the freezing generation section 17 of the expander 3. And the freezing generation unit 17 is in a high pressure state.

Thereafter, the expansion piston 16 in the expansion cylinder 15 of the expander 3 descends with a phase difference of about 90 ° with the compression piston 13. Thereby, the freezing generation part 17 as an expansion space is expanded, and the high-pressure refrigerant gas flowing from the regenerator 4 into the freezing generation part 17 is suddenly expanded,
Since the pressure of the refrigerant gas in the freezing generation unit 17 suddenly drops, the refrigerant gas has a low temperature.

When the expansion piston 16 starts to rise and the compression piston 13 retracts, the low temperature refrigerant gas passes through the regenerator 4 and returns to the compression space 11 through the gas flow path 5. At this time, in the regenerator 4, the regenerator material is cooled and cold heat is stored in the regenerator 4.

One thermal cycle is completed by the above steps, and this step is repeated by the reciprocating movement of the crank mechanism 24 of the crank mechanism section 9. As a result, the temperature of the freezing generator 17 and the temperature of the regenerator 4 gradually drop,
The refrigerant gas in the freezing generation unit 17 is set to a low temperature. In this state, in the freezing take-out unit 8, the cold heat of the freezing generation unit 17 is exchanged with an external low temperature tank as a heat utilization unit (not shown) to bring the cooling load of the external low temperature tank to the freezing temperature.

[0016]

However, in the conventional Stirling refrigerator 1 described with reference to FIG. 4, the guide portion 20 is used.
Also, although the guide portion 21 is provided with a seal portion, there is a problem that the seal function is not sufficiently exerted and the gas compressor 2 and the expander 3 as an operating space enter to reduce the refrigerating capacity and the like.

Conventionally, in the gas compressor 2, the crank mechanism 2 is used.
The connecting rod 25 extending from
No. 0 guide receiver 20a is slidably fitted to the cross guide 26, and the piston rod 27 of the cross guide 26 penetrates through the through hole 20b. The piston rod 27 is provided with an oil seal 33, and the compression piston 13 It is attached to the rear of the.

With this structure, the crank motion of the crank mechanism 24 is converted into the reciprocating motion of the compression piston 13, and
The lubricating oil 23 in the crank chamber 22 is prevented from entering the space 32 behind the compression piston 13.

However, it is difficult to completely seal the lubricating oil 23 with only the oil seal 33, and the lubricating oil 23 enters the space 32 at the rear. Therefore, there is a problem that the invading lubricating oil 23 mixes with the refrigerant gas to reduce the refrigerating capacity, and mixes with the regenerator material of the regenerator 4 to deteriorate the regenerator capacity.

The above is the compression piston 1 of the expander 3.
The same applies to 3 and the guide portion 21.

Therefore, it is an object of the present invention to provide an oil seal device that very effectively prevents invasion of lubricating oil into the operating portion.

[0022]

DISCLOSURE OF THE INVENTION The present invention provides an oil seal device for preventing the inflow of lubricating oil from a driving portion side filled with lubricating oil of a rod connected to a piston reciprocating in a cylinder to the piston side. A sealed space with oil seals is formed inside both ends where the rod penetrates, an oil drain hole is provided to discharge the lubricating oil accumulated in this space to the outside, and the oil seal interval is made larger than the stroke due to the reciprocating motion of the rod. In addition, the lubricating oil that has entered the space between the rod and the inner wall of the space has a size outside the range in which it rises due to the capillary phenomenon.

[0023]

With the above structure, since the distance between the oil seals provided at both ends is larger than the stroke due to the reciprocating motion of the rod, it is possible to prevent the lubricating oil from entering the cylinder side. Moreover, the lubricating oil that has entered the space between the rod and the inner wall of the space rises outside the range that rises based on the capillary phenomenon. Lubrication oil is greatly reduced from entering the cylinder side to discharge it through the oil vent hole. Therefore, it is possible to avoid the functional deterioration and the capacity deterioration of the part on the cylinder side and maintain the function and the capacity.

[0024]

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

FIG. 1 is a schematic diagram in which an oil seal device showing an embodiment of the present invention is applied to a Stirling refrigerator. The same reference numerals as those in FIG. 4 showing a conventional example indicate the same or corresponding portions. In this embodiment, the oil seal device 37 is applied to the compression cylinder 12 side of the gas compressor 2 and the expansion cylinder 15 of the expander 3 is used. An example in which the oil seal device 38 is applied to the side will be described. The configuration other than the oil seal device 37 and the oil seal device 38 is almost the same as the conventional example shown in FIG.

In FIG. 1, the oil seal device 37 on the gas compressor 2 side is fitted to one end side of the guide portion 20 to form a through hole 39 through which the piston rod 27 penetrates, and the expander 3 side. The oil seal device 38 of the
A through hole 40 is formed which is fitted on the upper end side of the through hole 40 to penetrate the piston rod 30.

Specifically, the oil seal device 37 is shown in FIG.
As shown in FIG.
The case 42 has a hole 42a at one end on the compression piston 13 side, and the step 42 communicates with the hole 42a.
and a case 4 at the other end with a cylindrical body having b and a hollow portion 42c.
Forming an annular convex portion 42d for fitting with one end of 3,
On the other hand, the case 43 has a hole 4 at the other end on the crank chamber 22 side.
3a having a stepped portion 43b and a hollow portion 4 communicating with the inside thereof.
3c and a cylindrical body formed with an oil drain hole 43e described later, and an annular recess 43 fitted to the case 42 described above at one end side.
and d.

In the case 42, the piston rod 27 is passed through the center of the case 42 and the oil seal 4 is provided at the step 42b.
4, and the oil seal 44 is fixed by an oil seal pressing plate 45 provided at the end edge of the hollow portion 42c. Correspondingly, in the case 43, the piston rod 27 is also penetrated in the center, and the oil seal 4 is attached to the step 43b.
4, the oil seal 44 is fixed by an oil seal holding plate 45 provided at the end edge of the hollow portion 43c.

In the oil seal device 37 described above, the gap A between the two oil seals 44 provided in the body case 41 is set to be sufficiently longer than the stroke due to the reciprocating movement of the piston rod 27, and the hollow portion 4
The space 46 formed by 2c and 43c has a large inner diameter so that the lubricating oil 23 does not rise due to a capillary phenomenon even if the compression piston 13 side is directed upward.

That is, the height hc of the liquid that rises in the capillary when the liquid is upright in the liquid is expressed by the following functional expression (1).

[0031]

## EQU00001 ## hc = f (.rho., G, D, .sigma..alpha.) ......... (1)

Where ρ: density of liquid g: acceleration of gravity D: diameter of capillary tube σ: surface tension α: contact angle

If the inner diameter of the space 46 is increased by the above function, the rise of the lubricating oil 23 due to the capillary phenomenon can be prevented.

On the other hand, the oil seal device 38, as shown in FIG.
7 comprises a case 48 and a case 49, and a case 4
8 has a hole 48a at one end on the expansion piston 16 side,
A cylindrical body communicating with the inside thereof and having a step portion 48b and a hollow portion 48c is formed with an annular convex portion 48d at the other end portion for fitting with one end portion of the case 49. Is a cylindrical body having a hole 49a at the other end on the side and having a step 49b, a hollow 49c, and an oil drain hole 49e which will be described later in communication therewith, and is fitted to the case 48 at one end. An annular recess 49d is formed.

In the case 48, the piston rod 30 is passed through the center of the case 48 and the oil seal 5 is attached to the step 48b.
0, and the oil seal 50 is fixed by the oil seal holding plate 51 provided at the edge of the hollow portion 48c. Correspondingly, in the case 49, the piston rod 30 is also penetrated in the center and the oil seal 5 is attached to the step portion 49b.
0 is applied, and the oil seal 50 is fixed by an oil seal holding plate 51 provided on the edge of the hollow portion 49c.

Like the above-described oil seal device 37, the oil seal device 38 described above has a structure in which the distance B between the two oil seals 50 provided in the main body case 47 is sufficiently longer than the stroke due to the reciprocating motion of the piston rod 30. Further, the space 53 formed by the hollow portions 48c and 49c has a large inner diameter dimension so that the lubricating oil 23 does not rise due to the capillary phenomenon.

With the above structure, when the crank mechanism 24 is rotated by the drive motor as the drive source to perform the crank motion, the connecting rod 25 extended to the crank mechanism 24 slides in the guide receiving recess 20a formed in the guide portion 20. The movably fitted cross guide 26 reciprocates, and the piston rod 27 connected to the cross guide 26 reciprocates the compression piston 13.

As a result, the lubricating oil 23 filled in the crank chamber 22 is transmitted through the cross guide 26 and the like to the guide portion 2.
No. 0 guide receiving recess 20a, the lubricating oil 23 penetrates through the through hole 39 of the oil seal device 37 and the oil seal 44 as the cross guide 26 reciprocates, and the lubricating oil 23 enters the inside of the oil seal device 37. To do.

At this time, the lubricating oil 23 accumulated on the crank chamber 22 side in the space 46 of the oil seal device 37 described with reference to FIG. 2 first travels along the piston rod 27 and gradually moves toward the compression piston 13 side in accordance with the reciprocating motion thereof. Moving. In this case, the distance A between the oil seals 44 provided at both ends of the oil seal device 37 is set sufficiently larger than the stroke associated with the reciprocating movement of the piston rod 27, so that the piston rod 2
The lubricating oil 23 is prevented from moving to the oil seal 44 on the side of the compression piston 13 along the path 7.

Moreover, even if the compression piston 13 side faces upward, the lubricating oil 23 falls by gravity and collects at the bottom of the space 46 because the inner diameter of the space 46 is sufficiently larger than the inner diameter that rises due to the capillary phenomenon. . As a result, the oil is collected in the crank chamber 22 from the oil escape hole 43e.

Similar to the operation of the oil seal device 37 described above, when the lubricating oil 23 enters the oil seal device 38 shown in FIG. 3 through the through hole 40, first, the piston rod 30 is moved in accordance with the reciprocating motion of the piston rod 30. The lubricating oil 23 moves to the expansion piston 16 side. in this case,
Oil seals 50 provided at both ends of the oil seal device 38
Since the distance B is sufficiently larger than the stroke of the piston rod 30, the lubricating oil 23 is prevented from moving to the oil seal 50 on the expansion piston 16 side along the piston rod 30.

It is conceivable that the lubricating oil 23 accumulated in the space 53 rises due to the capillary phenomenon.
By sufficiently setting the inner diameter of the lubricating oil 23, the lubricating oil 23 falls due to gravity and collects at the bottom of the space 53.
Is collected in the crank chamber 22 through the oil vent hole 49e.

As described above, the space between the oil seals provided at both ends of the space portion of the oil seal device is made sufficiently longer than the stroke due to the reciprocating movement of the piston rod, and the internal space having the inner diameter dimension in which the lubricating oil does not rise due to the capillary phenomenon. It is possible to prevent the invading lubricating oil from reaching the oil seal on the piston side along the piston rod due to the provision of.

Further, the accumulated lubricating oil can be recovered from the oil vent hole. Therefore, it is possible to significantly reduce the penetration of lubricating oil into the working space of the compression cylinder and expansion cylinder, significantly reduce the deterioration of the cold storage capacity and the deterioration of the heat exchanger capacity, and maintain the refrigeration capacity for a long time. can do.

In the present embodiment, the example in which the oil seal device is applied to the Stirling refrigerator has been described, but the present invention is not limited to this, and the drive unit using the lubricating oil and the operating unit operated by the rod by the driving unit are the lubricating oil. It can be applied when the function is deteriorated by the intrusion of

[0046]

As described above, according to the present invention, the space between the oil seals in the space is larger than the stroke due to the reciprocating motion of the rod, and the space between the rod and the inner wall in the space is made larger to invade the lubrication. Since the oil is prevented from rising due to the capillary phenomenon, it is possible to greatly reduce the intrusion of lubricating oil into the cylinder side, and it is possible to maintain the capacity and function by avoiding the deterioration of the capacity and function of the operating part on the cylinder side. To be

[Brief description of drawings]

FIG. 1 is a schematic view of a Stirling refrigerator to which an oil seal device according to an embodiment of the present invention is applied.

FIG. 2 is a sectional view showing an oil seal device on the compression piston side of FIG.

FIG. 3 is a sectional view showing an oil seal device on the expansion piston side of FIG.

FIG. 4 is a schematic view of a Stirling refrigerator with an oil seal showing a conventional example.

[Explanation of symbols]

 1 Stirling Refrigerator 9 Crank Mechanism 12 Compression Cylinder 13 Compression Piston 15 Expansion Cylinder 16 Expansion Piston 20 Guide 37,38 Oil Seal Device 39,40 Through Hole 41,47 Body Case 42,43,48,49 Case 42a, 43a , 48a, 49a Hole portion 42b, 43b, 48b, 49b Step portion 42c, 43c, 48c, 49c Hollow portion 42d, 48d Annular convex portion 43d, 49d Annular concave portion 43e, 49e Oil escape hole 44, 50 Oil seal 45, 51 Oil seal Holding plate 46,53 space

Claims (1)

[Claims] 1. An oil seal device for preventing the inflow of lubricating oil from a driving portion side filled with lubricating oil of a rod connected to a piston reciprocating in a cylinder to the piston side, wherein both ends of the rod penetrate inside An oil seal is formed to form a sealed space, an oil drain hole for discharging the lubricating oil accumulated in this space to the outside is provided, and the interval between the oil seals is made larger than the stroke due to the reciprocating motion of the rod, and the space is The oil seal device is characterized in that the size of the lubricating oil that has entered the space between the rod and the inner wall is outside the range where it rises based on the capillary phenomenon.