JPH0774627B2 - Sealing device and Stirling engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sealing device and a Stirling engine.

2. Description of the Related Art Conventionally, this type of sealing device has a structure as shown in FIG.

1 is a cylinder in which a shaft 2 is arranged. Reference numeral 3 denotes a bellows which separates the space 4 and the space 5, and the space 4 is filled with a fluid A and the space 5 is filled with a fluid B. The operation will be described below. During operation, the shaft 2 is moving in the axial direction, and one end of the bellows 3 is moving together with the shaft 2 while the fluid A in the space 4 and the fluid B in the space 5 are in motion.
Prevents and from mixing.

However, with such a structure, the pressure in the space 4 and the space 5
The bellows 3 has a defect that the bellows 3 is broken if the pressure difference exceeds the allowable value. In other words, this method has a drawback that it can be used only when the pressure difference between the space 4 and the space 5 is less than the allowable pressure difference between the bellows 3.

Therefore, the present invention prevents the bellows from breaking even if the pressures of the two kinds of fluids to be sealed are different, thereby expanding the range of use of the sealing device and improving the reliability.

Means for Solving the Problems And the technical means of the present invention for solving the above problems include a wall forming a part of a cylinder arranged so as to separate the inside of the cylinder into a first space and another space. Displacement of the shaft arranged so as to divide the other space into a second space communicating with the first space through a gap between the shaft and the wall and a third space which is the other space. The space between the first space and the second space that communicates with the first space and the second space, and the fluid A disposed in the flow path between the first space and the second space. A pump device for moving between the second space and the third space, a differential pressure detector for detecting a pressure difference between the second space and the third space, and a second space and a third space for receiving an output signal of the differential pressure detector. And a control device that sends a control signal to the pump device so that the pressure difference between the pressure control device and the pressure control device becomes less than or equal to a set value.

Action The action of this technical means is as follows.

That is, the partition wall seals the fluid A in the first and second spaces in the cylinder and the fluid B in the third space in the cylinder.

The control device receives the output signal of the differential pressure detector that detects the pressure difference between the second space and the third space, and is arranged in the flow path that connects the first space and the second space. A control signal is sent to the pump device so that the pressure difference between the second space and the third space is equal to or less than a set value.

The set value of this pressure difference is less than or equal to the allowable pressure difference of the partition wall to prevent the partition wall from breaking.

Example Hereinafter, a sealing device according to a first example of the present invention will be described with reference to FIG.

The purpose of this embodiment is to reliably seal the fluid A sealed in the spaces 10 and 12 and the fluid B sealed in the space 11 in the cylinder 6 regardless of the pressure difference between the spaces 10 and 12. It is to be.

In FIG. 1, 6 is a cylinder, 7 is a shaft arranged in the cylinder 6, 8 is a wall having a hole through which the shaft 7 penetrates, 9 is a space 10 and a space 11. This is a partition wall such as a bellows and a diaphragm which are arranged so as not to communicate with each other, and this embodiment is a case of a bellows.

Further, the fluid A is enclosed in the spaces 10 and 12, and the space 11
A fluid B is enclosed in. A flow path 13 connects the space 10 and the space 12, and a pump device 14 for moving the fluid A between the space 10 and the space 12 is provided on the way. On the other hand, 15
Is a differential pressure detector that detects the pressure difference between the space 10 and the space 11, 16 is a pump device 14 that receives the output signal of the differential pressure detector 15 so that the pressure difference between the space 10 and the space 11 is below a set value. Is a control device that sends a control signal to the.

Further, 17 reduces the flow rate of the fluid A coming and going between the space 10 and the space 12 through the gap between the wall 8 and the shaft 7, and the space 10 and the space 11
Is a rod seal for reducing the flow rate of the pump device 14 required for controlling the pressure difference and reducing the energy consumption.

The operation will be described below. Shaft 7 in cylinder 6 during operation
Is reciprocating in the axial direction. Further, the pressure in the space 11 and the pressure in the space 12 change due to the change in the operating state, and the pressure difference between the space 10 and the space 11 also changes accordingly.

By the way, the control device 16 receives the output signal of the differential pressure detector 15 and sends a control signal to the pump device 14 so that the pressure difference between the space 10 and the space 11 becomes a set value or less. That is, when the pressure difference between the space 10 and the space 11 is larger than the set value, and the pressure in the space 10 is larger than the pressure in the space 11, the control device 16 sends a control signal to the pump device 14 to move from the space 10 to the space 12. Fluid A
Is moved, and when it becomes less than the set value, a control signal is sent to the pump device 14 to stop the movement of the fluid A.

On the contrary, the pressure difference between the space 10 and the space 11 is larger than the set value,
Moreover, when the pressure in the space 10 is lower than the pressure in the space 11, the control device 16 sends a control signal to the pump device 14, and when the fluid A is moved from the space 12 to the space 10 and becomes less than the set value, the control signal is sent to the pump device 14. To stop the movement of the fluid A.

In this way, the pressure difference before and after the bellows 9 is kept below the allowable pressure difference of the bellows 9 to prevent the bellows 9 from breaking.

As described above, the present embodiment can prevent the bellows 9 from being broken even if the pressures in the space 12 and the space 11 are different, so that there is an effect that the usage range of the entire sealing device is expanded and the reliability is enhanced. .

In the present embodiment, the fluid A is enclosed in the spaces 10 and 12, and the fluid B is enclosed in the space 11.
11 works well even in a vacuum. Also a differential pressure detector
The same effect can be obtained by providing two pressure detectors instead of 15, and when the space 11 is a vacuum, the same effect can be obtained by providing one pressure detector for detecting the pressure in the space 10. .

Next, a sealing device according to the second embodiment of the present invention will be described with reference to FIG.

The purpose of this embodiment is the same as that of the first embodiment. This embodiment is different from the first embodiment in that a deformation amount detector 18 is provided instead of the differential pressure converter 15 in the first embodiment. In the following description, the points different from the first embodiment will be mainly described. Further, parts having the same configurations and effects as those of the first embodiment are designated by the same reference numerals.

In FIG. 2, reference numeral 18 is a deformation amount detector for detecting the deformation amount of the bellows, and more specifically, an eddy current type displacement gauge or the like is used. An example using an eddy current type displacement meter is a detector.
18 outputs a signal of the distance from the bellows 9, which corresponds to the amount of deformation. For example (pressure in space 10-space 11
The bellows 9 expands and the distance between the detector 18 and the bellows 9 decreases. Conversely, the bellows 9 contracts as (pressure in the space 10-pressure in the space 11) decreases, and the distance between the detector 18 and the bellows 9 increases.

By the way, the output signal of the detector 18 varies depending not only on the surface of the bellows 9 (pressure in the space 10-pressure in the space 11) but also in the position of the shaft 7. With proper selection, the influence of the position of the shaft 7 can be made practically acceptable.

The operation will be described below. Shaft 7 in cylinder 6 during operation
Is reciprocating in the axial direction. Further, the pressure in the space 12 and the pressure in the space 11 change due to the change in the operating state, and the pressure difference between the space 10 and the space 11 also changes accordingly.

By the way, the control device 16 receives the output signal of the deformation amount detector 18 and sends the control signal to the pump device 14 so that the deformation amount becomes equal to or less than the set value, that is, the deformation amount is larger than the set value,
Moreover, when the bellows 9 is inflated, the control device 16 sends a control signal to the pump device 14, moves the fluid A from the space 10 to the space 12, and sends a control signal to the pump device 14 when the fluid A is below a set value. Stop moving.

On the contrary, when the deformation amount is larger than the set value and the bellows 9 is contracted, the control device 16 sends a control signal to the pump device 14 to move the fluid A from the space 12 to the space 10 so that the amount of the fluid A becomes less than the set value. For example, a control signal is sent to the pump device 14 to stop the movement of the fluid A.

As described above, the deformation amount of the bellows 9 is kept below the set value to prevent the bellows 9 from breaking.

As described above, the present embodiment can prevent the bellows 9 from being broken even if the pressures in the space 12 and the space 11 are different, so that there is an effect that the usage range of the entire sealing device is expanded and the reliability is enhanced. .

Next, a Stirling engine according to a third embodiment of the present invention will be described with reference to FIG.

The purpose of this embodiment is to provide a structure in which a Stirling engine and a fluid machine driven by the Stirling engine are integrated with each other.The working fluid of the Stirling engine and the fluid in the fluid machine are highly reliable even if the fluid pressure changes. It is to seal.

In this embodiment, a compressor is used as the fluid machine,
More specifically, the compressor is an example in which a refrigerant compressor used in a refrigerator or the like and a free piston type Stirling engine are used as the driving means of the compressor piston, and the whole is composed of an engine part, a seal part, and a compressor part. ing. The structure and operation of the seal portion are the same as those of the first embodiment, and the portions having the same structure and operation as those of the first embodiment have the same reference numerals.

First, the engine section will be described. Reference numeral 19 denotes a container in which a working fluid of the Stirling engine such as helium and nitrogen (hereinafter abbreviated as helium) is enclosed. 20 is a heater for heating the working fluid, 21 is a cooler for cooling the working fluid, and 22 is a regenerator. Reference numeral 23 is a displacer that moves up and down while sliding on the inner wall of the container 19, 24 is an output piston that moves up and down while sliding on the inner wall of the container 19, and 25 is a shaft connected to the output piston 24.

Next, the compressor section will be described. 26 is a cylinder, 27 is an axis
A compressor piston which is connected to 25 and slides in the cylinder 26 on the inner wall of the cylinder 26 or moves through a gap with the cylinder 26, 28 is a low-pressure passage through which low-pressure fluid flows, 29 is an intake valve,
30 is a compression chamber, 31 is a discharge valve, 32 is a high pressure passage, 33 is a condenser, 34 is an expansion valve, and 35 is an evaporator. Further, reference numeral 36 is a compression coil spring for preventing the compressor piston 27 from colliding with the cylinder 28 due to the pressure difference between the helium and the refrigerant while the operation is stopped.

The operation will be described below. When the displacer 23 goes down, the volume of the compression space 37 decreases and the volume of the expansion space 38 increases, so that the pressure of the compression space 37 becomes higher than the pressure of the expansion space 38, and the pressure difference between the compression space 37 and the cooler 21 is caused by this pressure difference. The cold helium inside flows through the regenerator 22, the heater 20 towards the expansion space 38, at which time the helium is heated by the regenerator 22 and the heater 20, and the regenerator.
22 is cooled in reverse.

In this way, the low-temperature helium is heated, so the compression space
The pressure of a space (hereinafter, abbreviated as an operating space) that is a combination of 37, the cooler 21, the regenerator 22, the heater 20, and the expansion space 38 increases, and the output piston 24 is pulled down. The output piston 24 then works on the rod 25. On the other hand, the displacer 23
As the pressure continues to decrease, the pressure in the gas spring space 39 gradually increases, and finally the displacer 23 stops decreasing and this time, on the contrary, starts increasing. When the displacer 23 rises, the volume of the compression space 37 in turn increases and the volume of the expansion space 38 decreases, so that the pressure in the expansion space 38 becomes higher than the pressure in the compression space 37, and this differential pressure causes the expansion space 38 and the heater 20 to move. The high temperature helium inside the chamber flows through the regenerator 22 and the cooler 21 toward the compression space 37, at which time the helium is cooled by the regenerator 22 and the cooler 21. And regenerator
22 is heated in reverse. In this way, the high temperature working fluid is cooled, so the pressure in the working space becomes low and the output piston 24
Pull up. The output piston 24 then works on the shaft 25.

On the other hand, if the displacer 23 continues to rise, the pressure in the gas spring space 39 gradually decreases, and finally the displacer 23 stops rising and this time, on the contrary, begins to descend. In the above-described round-trip process, helium converts a part of the heat obtained by the heater 20 into work for the shaft 25 and a part of the cooler.
Discard at 21. Normally, the phase angle at the position of the displacer 23 is 60 ° to 90 ° with respect to the phase angle at the position of the output piston 24.
゜ It is progressing.

By the way, in the compressor section, the compressor piston 27 connected to the shaft 25 driven by the free piston type Stirling engine is moving at the same speed as the output piston 24. As the compressor piston 27 moves up and down, the low-pressure low-temperature gas-phase refrigerant in the low-pressure passage 28 flows into the compression chamber 30 through the suction valve 29, is compressed, becomes high-pressure high-temperature, and passes through the discharge valve 31 and high-pressure passage.
Spill to 32. Further, it flows into the condenser 33, becomes a high-pressure liquid phase, flows into the expansion valve 34, flows out, becomes a low-pressure low-temperature gas-liquid two-phase, is further heated in the evaporator 32, becomes a low-pressure low-temperature gas phase, and flows into the low-pressure flow path 28. To do.

The compressor piston 27
The sum of the work done by the refrigerant as the refrigerant and the heat obtained by the refrigerant in the evaporator 35 is discarded from the refrigerant in the condenser 33, and cold heat and warm heat are available in the evaporator 35 and the condenser 33, respectively.

Next, the seal portion will be described. The seal portion has the same function as in the first embodiment. That is, the bellows 9 has a space 12
The helium inside and the refrigerant in the space 11 are sealed. In addition, the present sealing device uses the bellows 9 to reduce the pressure difference between the space 10 and the space 11.
The pressure difference is kept below the permissible pressure difference to prevent the bellows 9 from breaking. Therefore, for example, even if the operating conditions of the compressor change, the pressure in the low pressure passage 28 and the pressure in the high pressure passage 32 change, and the pressure in the space 11 changes accordingly, the bellows 9 is not destroyed. This is also the case when the pressure in the space 12 changes.

As described above, the present embodiment is a combination of the sealing device and the Stirling engine for driving the compressor in the first embodiment, so that the bellows 9 is destroyed even if the pressures in the space 12 and the space 11 are different. Since it is possible to prevent this, the range of use of the entire sealing device is expanded and reliability is also increased. That is, even if the helium pressure in the space 12 of the Stirling engine and the refrigerant pressure in the space 11 of the compressor are operated under different conditions, the bellows 9 will not be destroyed, and the utilization range of the entire Stirling engine and the compressor will be expanded. This has the effect of increasing reliability.

EFFECTS OF THE INVENTION According to the present invention, even if the pressures of the fluid A and the fluid B are different, the partition wall is not broken, and as a result, the utilization range of the sealing device is expanded and the reliability is improved.

[Brief description of drawings]

1 is a vertical sectional view of a sealing device according to a first embodiment of the present invention, FIG. 2 is a vertical sectional view of a sealing device according to a second embodiment of the present invention, and FIG. 3 is a third sectional view of the present invention. FIG. 4 is a vertical sectional view of the Stirling engine in the embodiment, and FIG. 4 is a vertical sectional view of the conventional sealing device. 6 ... Cylinder, 7 ... Shaft, 9 ... Bellows, 13 ... Flow path, 14 ... Pump device, 15 ... Differential pressure detector, 16 ... Control device, 18 ... Deformation amount detector, 19 ...... Container, 20 ...... Heater, 21 ...... Cooler, 22 ...... Regenerator, 23 ...... Displacer, 24 ...... Output piston, 25 ...... Shaft, 27 ...... Compressor piston, 26 ...... Cylinder, 29 ... Suction valve, 31 ... Discharge valve, 33
...... Condenser, 34 …… Expansion valve, 35 …… Evaporator, 36 …… Compression coil spring.

Claims (3)

[Claims] 1. A cylinder, a shaft disposed in the cylinder, and a hole through which the shaft penetrates in a part of the cylinder so as to divide the inside of the cylinder into a first space and another space. A wall that is provided and forms a part of the cylinder; a second space that communicates the other space with the first space through a gap between the shaft and the wall; and a third space that is the other space. A partition wall whose shape changes with the displacement of the shaft arranged so as to be divided into two parts; a fluid A enclosed in the first space and the second space;
The fluid B sealed in the third space, the flow passage that connects the first space and the second space, and the fluid A disposed in this flow passage are used for the first space and the second space. A pump device for moving between the second space and the third space, a differential pressure detector for detecting a pressure difference between the second space and the third space, and a second space and a third space for receiving an output signal of the differential pressure detector. And a control device that sends a control signal to the pump device so that the pressure difference between the seal device and the pump device becomes less than or equal to a set value. 2. A cylinder, a shaft arranged in the cylinder, and a hole through which the shaft penetrates, which are arranged so as to separate the inside of the cylinder into a first space and another space. A wall that is provided and forms a part of the cylinder; a second space that communicates the other space with the first space through a gap between the shaft and the wall; and a third space that is the other space. A partition wall whose shape changes with the displacement of the shaft arranged so as to be divided into two parts; a fluid A enclosed in the first space and the second space;
The fluid B sealed in the third space, the flow passage that connects the first space and the second space, and the fluid A disposed in this flow passage are used for the first space and the second space. A pump device to be moved between them, a deformation amount detector for detecting the deformation amount of the partition wall, and an output signal of the deformation amount detector for receiving a control signal to the pump device so that the deformation amount becomes equal to or less than a set value. A sealing device comprising a feeding control device. 3. A container, an engine space in which the shaft is disposed in the container, a hole through which the shaft penetrates, and a working fluid E of the engine is enclosed in the container, and the like. Is provided so as to be separated from the space, the heating means for heating the working fluid E, the cooling means for the working fluid E, and the shaft that is fixed integrally with the shaft and is moved from the working fluid E while moving with respect to the container. An output piston that works on the shaft, and the other space is divided into a second space that communicates with the engine space through a gap between the shaft and the wall and a third space that is the other space. A partition wall whose shape changes with the displacement of the shaft disposed in the third space, a fluid B sealed in the third space, a flow path connecting the first space and the second space, and this flow path. A pump device disposed in the passage for moving the fluid A between the first space and the second space; and a second space. When a differential pressure detector for detecting a pressure difference between the third space, the receiving an output signal of the differential pressure detector 2
And a controller for sending a control signal to the pump device so that the pressure difference between the space and the third space is equal to or less than a set value.