JP2008151086A - Volumetric variation member for stirling engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To devise a Stirling engine preventing leakage of working gas with the usage of a bellows so that deterioration in output and thermal efficiency caused by increase of a dead space can be prevented and a special bellows can be dispensed with. <P>SOLUTION: The volumetric variation member for the Stirling engine comprises a structure for storing the bellows having the working gas in a cylinder fitted with a piston, and filling the whole of a region formed by a wall surface of the bellows and a cylinder inner surface and a piston upper surface with fluid, and forms a series of cycles for pushing out the piston by transmitting elongation movement of the bellows by expansion of the working gas sealed in the bellows to the piston through a filling liquid, and compressing the sealed working gas by transmitting the compression force for pushing the piston from the outside to the bellows through the filling liquid. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a Stirling engine member, and more particularly to a Stirling engine volume fluctuation member that uses a bellows to prevent leakage of working gas.

A Stirling engine is a series of products that enclose a working gas inside, increase the volume by heating and expanding the working gas, and compress the expanded working gas to the original volume while cooling. It is a heat engine that constitutes a cycle and extracts the difference between the work amount obtained during expansion and the work amount required during compression as an output.
Since the theoretical thermal efficiency of a Stirling engine is equal to the thermal efficiency of a Carnot engine, which is the theoretical limit value of a heat engine, research and development have been conducted by many scholars and research institutions to realize a motor with high thermal efficiency. However, the results are not always successful, leakage of working gas from sliding parts such as pistons and rods, excessive heat dissipation from the radiator, unexpectedly low thermal efficiency, and complex processing requiring advanced processing techniques. Many unsolved problems remain, such as insufficient heat exchangers and acceleration / deceleration performance. Among these, a particularly serious problem is related to leakage of working gas from the sliding portion and low thermal efficiency.
Regarding leakage of working gas from sliding parts such as pistons and rods, [Patent Document 1] and [Patent Document 2] disclose a method of using a bellows. However, in the method of [Patent Document 1], an intermediate air chamber acts as a kind of dead space and there is a concern about a decrease in output. In the method of [Patent Document 2], a bellows requires a high pressure resistance, and the cost is high. Both are difficult to put into practical use.

Published patent publication Sho 56-77537 Published Patent Publication Sho 58-150001 Hisashi Ishiki, "Development of Stirling Engine" Industrial Research Committee, published on June 26, 1995 Satoshi Yamashita et al. “Theory and Design of Stirling Engines” Sankaido, July 30, 1999

The present invention is a Stirling engine that uses a bellows to prevent leakage of working gas, eliminates a decrease in output and thermal efficiency due to an increase in dead space, and does not require a special bellows with high pressure resistance. The task was to improve the engine.

In order to solve these problems, the present inventor paid attention to the incompressibility, tolerability, and pressure transmission properties of the liquid, and as a result of repeated research considering that this could be used to solve this problem. The present inventors have found that the problem can be solved by the following method.

This is true not only for Stirling engines, but for reciprocating engines as a whole, but reciprocating engines always have a part that changes in volume like a cylinder fitted with a piston. The difference between the amount of work corresponding to the product of volume (the integration of pressure and volume when pressure changes) and the amount of work necessary for compression is to be taken out as an output.
In the present invention, a component having a function of changing the volume, such as a cylinder fitted with a piston of a general reciprocating engine, is referred to as a volume changing member. Further, a unit in which a piston is fitted to a cylinder and integrated is called a piston / cylinder.

Assume that a bellows is first placed in a piston / cylinder, and the entire region formed by the wall surface of the bellows, the inner surface of the cylinder, and the upper surface of the piston is filled with liquid. In the present invention, the bellows piston is stored in the piston / cylinder in this way, and the entire region formed by the wall surface of the bellows, the cylinder inner surface and the upper surface of the piston is filled with liquid, and the cylinder inner surface and the bellows wall surface and A region filled with the liquid formed by the upper surface of the piston is referred to as a liquid sealing chamber.
Hydrogen gas or helium gas is sealed as working gas inside the bellows of the bellows piston. The sealed pressure of the working gas varies depending on the engine output and is about 0.1 to 20 megapascals. As this working gas, the performance is slightly inferior, but it is also possible to use air or nitrogen gas.

The bellows piston has only one bellows inside the cylinder and encloses the working gas inside it, and the bellows piston that has a bellows on the outside and inside like the one used in the alpha-type Stirling engine. There is.
The function of the bellows piston is to store the working gas in the bellows so that the working gas does not leak, and the expansion of the bellows due to the expansion of the working gas enclosed in the bellows is a liquid filling substance in the liquid seal chamber. When the compression force that pushes out the piston by pushing to the piston from the outside works, this force is transmitted to the bellows via the liquid filling material to compress the sealed gas in the bellows. It is to make.
Thus, the bellows piston transmits the movement of the bellows to the piston or the movement of the piston to the bellows, but it is the liquid that mediates it. Since the volume of liquid does not change with pressure changes unlike gas, displacement of displacement from the piston to the bellows or from the bellows to the piston is instantaneous, and the displacement of the piston and the displacement of the bellows are It has the same feature as volume.

In a conventional Stirling engine, a cylinder fitted with a piston is used as a volume changing member. However, as mentioned at the outset, leakage of working gas from sliding parts such as pistons and rods is a major problem, which is one of the major factors hindering the practical use of Stirling engines. Instead of this problematic piston / cylinder, a bellows / piston is used as a volume changing member of the Stirling engine, and the working gas is sealed inside the bellows, so that the sealed working gas is contained in the piston / cylinder. Therefore, it is possible to prevent the enclosed gas from leaking, which solves the problem imposed on the present invention. Since the piston / cylinder and the bellows piston have almost the same function as the volume changing member, the volume change due to the expansion of the working gas becomes the movement of the bellows piston as in the piston / cylinder. The movement can be taken out as power by the driving device.
As a result, it is possible to eliminate the state in which the working gas touches the sliding portion without lowering the output, thereby eliminating the leakage of the working gas. In this case, since the pressure of the working gas is borne by the piston and the cylinder, the bellows itself is not required to have such a pressure resistance, and the above two problems can be solved. As will be described in detail later, in addition to these, an increase in thermal efficiency due to isothermal expansion and isothermal compression can be expected.

A liquid having a low density and a low viscosity is suitable for the liquid filling chamber of the bellows piston. For bellows and pistons used at low temperatures, use low viscosity oil such as spindle oil. However, it is necessary to pay some attention to the bellows piston used on the high temperature side of the Alpha Stirling engine. For bellows and pistons used at relatively low temperatures, silicone oil with high heat resistance can be used. However, in the bellows piston used at several hundred degrees Celsius, such oils cannot be used because they cause thermal decomposition. In this case, it is necessary to use a substance that is liquid under use conditions, such as metal sodium, in the molten state. Of course, such a molten metal can be used for a bellows piston used at a relatively low temperature as long as it is used at a temperature higher than its melting point.

The fact that the bellows is filled with a liquid is very convenient when the working gas is to be heated or cooled in the volume changing member. This is because an isothermal compression and isothermal expansion Stirling engine can be easily realized by sending and circulating the liquid filled around the bellows to a heat exchanger provided outside as a heat transfer medium. The filled liquid fulfills the function of transferring both pressure and heat and is extremely efficient. The bellows piston in which the filling liquid is circulated in this way is called a circulation type bellows piston. In this case, since the same pressure as the working gas is applied to the filling liquid, a sealed circulation system including no circulation gas including a circulation pump must be provided between the bellows piston and the heat exchanger. The heat exchange with fins for the circulation type is called a fin type.

Another point to note with the bellows piston is that the upper surface of the piston and the lower surface of the bellows should not be fixed over the entire surface. This is because when the bellows is shrunk, there is no place for the filling liquid in the ridges, and the pressure rises abnormally to destroy the bellows. In order to avoid this, it is necessary to allow the filling liquid to go around between the upper surface of the piston and the lower surface of the bellows. If fixed, the fixing point should be only the center and the bottom surface of the bellows should be flexible like a diaphragm so that the filling liquid can be circulated.

The main effects obtained by the present invention are as follows.
(1) The working gas is in the bellows and does not come into contact with sliding parts connected to the outside air such as pistons and rods. Therefore, the working gas does not leak from sliding parts such as pistons and rods.
(2) The liquid has the property that the volume hardly changes even if the pressure changes, and the volume of the liquid filled in the piston / cylinder hardly changes even if the pressure of the working gas changes. The pressure change of the working gas in the bellows can be immediately transmitted to the piston and the driving device connected thereto. Therefore, there is no increase in the dead space and the output does not decrease.
(3) Since the bellows is housed in a piston / cylinder filled with liquid, a pressure approximately equal to the internal pressure of the bellows is generated inside the cylinder to cancel the pressure. Therefore, even if the pressure of the working gas is high, The withstand voltage of is not so high. For this reason, bellows can be made of thin metal. This means that the thermal resistance of the bellows is reduced.
(4) When oil is used as the filling liquid, the sliding portion between the piston and the cylinder is oil-lubricated, so that the piston is lubricated and the side thrust problem is solved. For this reason, it is not necessary to use a complicated mechanism such as a Lombic mechanism, a crosshead mechanism, or a Scotch yoke mechanism for the drive device, and a crank mechanism used in a normal engine can be used. Of course, the above-described various mechanisms that have been used in the past can also be used.
(5) An isothermal compression and isothermal expansion Stirling engine can be easily realized by sending the liquid filling the liquid seal chamber around the bellows to an external heat exchanger and circulating it. As a result, improvement in thermal efficiency can be expected, so that the problem of “excessive heat radiation from the radiator and low thermal efficiency” described at the beginning can be solved. In this case, an improvement in heat transfer performance can be expected because the heat transfer area is increased by the bellows rod.
(6) Since only the liquid flows through the heat exchanger and the working gas does not flow, there is no increase in dead space due to the heat exchanger. For this reason, for a combustion gas having a low heat transfer coefficient, a large heat exchanger having a large heat transfer area can be used to improve the heat exchange performance.
(7) Since no rod seal or mechanical seal with large power loss is required, the thermal efficiency is improved.

Among these effects, the first and seventh terms are the same for a known bellows-type Stirling engine, and are not limited to the present invention. However, the second to sixth terms are characteristic of the Stirling engine according to the present invention and are not found in known Stirling engines. In particular, the second, third, fifth, sixth and seventh terms play an extremely important role in increasing the output and thermal efficiency of the Stirling engine.

Here, the reason why isothermal compression and isothermal expansion are required to increase the thermal efficiency of the Stirling engine will be briefly described.
In the conventional Stirling engine, when the compressed working gas is heated, the working gas passes through the low temperature heat exchanger before passing through the high temperature heat exchanger and the regenerative heat exchanger. This is because the heat of the working gas whose temperature has increased due to compression is cooled by a low-temperature heat exchanger and discarded. In the case of adiabatic expansion, there is no heat loss, but the working gas that has fallen in temperature due to adiabatic expansion is heated before being sent to the regenerative heat exchanger, so extra heat must be stored in the regenerative heat exchanger. As a result, the capacity of the regenerative heat exchanger must be increased.
In order to solve these problems, it is necessary to return to the basics of the Stirling engine and realize isothermal expansion and isothermal compression of the working gas.

The reason why a conventional Stirling engine cannot be isothermally compressed or expanded is simply explained. A conventional Stirling engine sends a working gas to a heat exchanger that is provided separately from a variable volume member such as a cylinder or bellows. It is because it is doing. This point will be briefly described. Consider the case where the power piston is in the compression stroke. When cooling and compressing with a heat exchanger provided separately from the volume variable member, the working gas that was cooled at an early stage and entered the low temperature chamber side of the cylinder was first cooled even if the pressure later increased. However, since the pressure increases without cooling after that, it becomes adiabatic compression and not isothermal compression. For this reason, the temperature of working gas rises from the time of entering a cylinder. In the expansion stroke, on the contrary, the working gas that is heated at an early stage and enters the high temperature chamber side of the cylinder is adiabatic expansion and does not become isothermal expansion because the pressure is lowered without being heated.

To achieve isothermal expansion and isothermal compression, the working gas that has entered the volume variable member in the initial stage of the expansion stroke is always heated during expansion, and the operation that has entered the volume variable member in the initial stage of the compression stroke. It is necessary to keep the gas cool during compression. For this purpose, it is necessary to heat and cool the working gas in the volume changing member in the volume changing member. In the present invention, heating the working gas inside the volume changing member is called internal heating, and cooling the working gas inside the volume changing member is called internal cooling. When this term is used, it can be said that internal heating and internal cooling are necessary to achieve isothermal expansion and isothermal compression.

It is quite difficult to realize these with a conventional Stirling engine. Usually, heating is performed by a heat exchanger provided outside, and external heating and cooling are performed by an external heat exchanger. Internal cooling can be realized relatively easily. This is because the liquid filled in the bellows piston is sent to an external heat exchanger and returned to the bellows piston for circulation, so that the bellows surface is brought to a temperature close to that of the external heat exchanger. This is because the working gas that is maintained and sealed inside is also heated or cooled to a temperature close to this. Unlike the conventional Stirling engine, it is not necessary to draw the working gas out of the volume variable member and send it to the heat exchanger, and the dead space can be reduced accordingly. Furthermore, the heat exchange between the working gas and the bellows to the heat transfer medium has a large heat transfer coefficient because the liquid and metal are between the heat transfer medium and the bellows, and the heat gas pressure is also high between the bellows and the working gas. Since the transfer coefficient is large, the result is excellent heat exchange performance. Moreover, since the thickness of the bellows can be reduced as described in paragraph 3 of paragraph [0013], the thermal resistance of the bellows can be reduced, and further, as described in paragraph 5 of paragraph [0013]. This contributes to an increase in the heat transfer area and increases the amount of heat transfer.

A structure of a bellows piston and a method of constructing a Stirling engine using the bellows piston will be described based on embodiments.

FIG. 1 is a sectional view showing the structure of a double bellows piston used in a beta type Stirling engine.
This machine is different from the known beta type Stirling engine in that power is generated by the bellows piston and the working gas is cooled in the bellows piston. It is the same as the beta type Stirling engine. A known Lombic mechanism or the like can be used as the driving device, but it is not an object of the present invention, and thus the description thereof is omitted. The structure of this machine will be described below with reference to the drawings.
An outer bellows 101 and an inner bellows 102 made of a thin stainless steel plate are accommodated in a space created by the cylinder 111 and the power piston 113, and the liquid seal chamber 115 between the outer bellows 101 and the cylinder 111 has a viscosity. Machine oil such as low spindle oil is filled as a filling liquid, and helium gas or hydrogen gas is sealed in the low temperature space 116 between the outer bellows 101 and the inner bellows 102. The low temperature space 116 and the high temperature space 117 are connected as will be described later, and this gas is simultaneously enclosed in the high temperature space. This gas functions as a working gas for the Stirling engine, and air or nitrogen gas may be used if the performance may be slightly sacrificed.

In a normal Stirling engine, the working gas is led to an external heat exchanger and heated and cooled there. However, if the working gas is heated and cooled through the cylinder wall or bellows wall without drawing the working gas to the outside as in this machine, improvement in thermal efficiency is expected. it can. Although the high-temperature space 117 and the low-temperature space 116 are separated by the displacer piston 110, the displacer piston 110 also serves as a regenerative heat exchanger, and is formed by laminating a disk-shaped wire mesh. The working gas can pass freely with low pressure loss.
When the hot working gas is pushed by the displacer piston 110 toward the low temperature space 116, the heat of the working gas is given to the displacer piston 110, and conversely, the cold working gas is pushed by the displacer piston 110 into the high temperature space 117. When heading, the applied heat is received from the displacer piston 101. The method of passing the working gas through the displacer piston 110 as described above is also described in [Non-Patent Document 1] and is known.

The diameter of the displacer piston 110 is slightly smaller than the inner diameter of the cylinder 111 so that the displacer piston 110 and the cylinder wall do not contact each other. Naturally, a part of the working gas passes through this gap, but the displacer piston 110 is a type in which the working gas passes through the inside and functions as a regenerative heat exchanger, and between the displacer piston 110 and the cylinder 111. The slight gap does not have a significant adverse effect on the performance of the Stirling engine.

The fins 112 provided on the outer wall surface on the high temperature space 117 side of the cylinder 111 are for efficiently receiving the heat of the combustion gas applied to the outer wall and transmitting it to the working gas. In this example, the high temperature side directly heats the cylinder outer wall.
This machine has no sliding surface for working gas and does not require sealing, but the sliding surface between the cylinder 111 and the power piston 113 and the sliding surface between the power piston rod 114 and the displacer piston rod 118 are sealed. is required. However, this seal may be used to prevent liquid leakage and is much simpler than an oilless seal against hydrogen gas or helium gas.

The filling liquid in the liquid sealing chamber 115 needs to function as a carrier for removing heat generated during compression of the working gas in order to realize isothermal compression, and a circulation pump ( It is sent to a heat exchanger (not shown) by a not-shown), where it is returned to the liquid return port 121 after cooling the filling liquid. Since the pressure of the working gas is applied as it is in this circulation system, it is completely sealed so that the pressure is not released, and further, no gas is contained. The circulating pump used here needs to have a sealing property that can withstand the pressure of the working gas, although the lift does not have to be so large. In the above heat exchanger, only the filling liquid flows and the working gas does not flow, so there is no need to worry about an increase in the dead space, and a large heat transfer area can be used.

The point that the phase of the displacer piston 110 is advanced by 90 degrees from the power piston 113 is the same as that of a normal Stirling engine, and the operation principle and the like are not different from those of a normal Stirling engine.
When the working gas is fed into the high temperature space 117 by the displacer piston 110, the pressure of the working gas increases and pushes down the lower surface 103 of the bellows. This movement is immediately transmitted to the filling liquid filled in the liquid sealing chamber 115 and pushes down the power piston 113. These are transmitted to a driving device (not shown) through the power piston rod 114 and taken out as an output from the driving device, but these are the same as the known Stirling engine.

FIG. 2 is a partial cross-sectional view showing a circulating bellows piston used in a Stirling engine. This bellows piston can constitute an engine imitating a gamma-type Stirling engine or a rotary swash plate type double-acting four-cylinder Stirling engine in addition to an alpha-type Stirling engine.
A bellows 201 made of a thin stainless steel plate is accommodated in a space created by the cylinder 211 and the piston 213, and helium gas is sealed in the gas space 216 inside the bellows 201. The liquid filled in the liquid sealing chamber 215 between the bellows 201 and the inner surface of the cylinder 211 is as described in paragraph [0010].

The liquid sealing chamber 215 is provided with a plurality of liquid outlets 220 for sending out the filling liquid therein and a plurality of liquid return ports 221 for returning the liquid, and there is one liquid outlet 220 for the same bellows piston. Are combined into a circulation pump (not shown), sent from there to a heat exchanger (not shown) for heat exchange, and then returned to each liquid return port 221. This circulatory system must be a closed system containing no gas, as in [Example 1]. A part of the liquid outlet 220 or the liquid return port 221 is blocked by the upward movement of the piston 213, but not all the liquid outlets 220 or the liquid return ports 221 are blocked.

The upper part of the cylinder 211 is slightly depressed, and a vent hole 210 is attached at the center. The upper depression is for reducing the amount of working gas remaining in the bellows when it shrinks. The piston rod 214 is connected to a driving device (not shown).
This bellows piston heats or cools the filling liquid with a heat exchanger provided separately. However, since the working gas is heated or cooled inside the volume changing member, the Stirling engine using this is operatively operated. Is an internal heating / cooling type.

FIG. 3 is a partial cross-sectional view showing a fin-type bellows piston used in a Stirling engine. [Embodiment 2] is a type in which heat is exchanged by circulating between a heat exchanger separately provided with a filling liquid and the cylinder 211. In this example, heat is exchanged by attaching fins 312 to the upper part of the cylinder 311. It is like that.
This is basically the same as [Embodiment 2], and includes a bellows 301, a cylinder 311, a piston 313, a liquid sealing chamber 315, and a gas space 316. The filling liquid only transmits pressure and heat, and does not have a liquid outlet or liquid return port for circulation. Since the filling liquid is not circulated, the heat transfer performance is slightly inferior. However, since the filling liquid is swung by the vertical movement of the piston, a certain degree of heat transfer can be secured. The filling liquid needs to be changed depending on the use temperature as in [Example 2].
In this bellows piston, the outer wall of the cylinder 311 is directly heated or cooled, but the working gas is heated or cooled inside the volume changing member via the filling liquid. The operation is the internal heating / cooling type as in 2].

FIG. 4 is a partial cross-sectional view showing a bellows piston used in a Stirling engine of the type heated or cooled by a high temperature heat exchanger or a low temperature heat exchanger separately provided with a working gas. If there is a fin, the heat is dissipated from the fin and the heat efficiency is lowered, so the fin is not attached. However, the rest is structurally the same as in [Example 3], and is the same as the bellows 401, cylinder 411, piston 413, liquid sealing chamber. 415 and a gas space 416. The filling liquid needs to be changed depending on the use temperature as in [Example 2].
Since the working gas is heated and cooled by a heat exchanger provided outside, the Stirling engine using this is an external heating and cooling type.

FIG. 5 is a schematic view showing an example in which an internal heating / cooling type Stirling engine is configured using a bellows piston.
In this example, only the regenerative heat exchanger is attached to the outside, and the working gas is heated and cooled inside the bellows, which is an internal heating and cooling type alpha Stirling engine. Since the working gas can be heated and cooled inside the volume varying member, it becomes isothermal expansion and isothermal compression.
In this figure, the bellows piston is fin-shaped, the high temperature side bellows piston 501 is heated by the external high temperature heat source 511, and the low temperature side bellows piston 502 is cooled by the external low temperature heat source 513. The filling liquid can also be heated or cooled by a heat exchanger provided separately using the circulation type bellows piston shown. The high temperature side bellows piston 501 and the low temperature side bellows piston are connected with a regenerative heat exchanger 512 interposed therebetween. This type of Stirling engine is an internal heating and cooling type in order to heat and cool the working gas existing inside the volume changing member through the filling liquid.
The high temperature side bellows piston 501 and the low temperature side bellows piston 502 are connected to the crankshaft 532 by a connecting rod 531 to drive the flywheel 533. The phase of the high temperature side bellows piston 501 is set to advance 90 ° with respect to the phase of the low temperature side bellows piston 502.

An example in which an external heating / cooling type Stirling engine is constructed using a bellows piston is shown in FIG. The heating / cooling method shown here is generally widely used, and the high temperature side bellows piston 601 and the low temperature side bellows piston 602 include a high temperature heat exchanger 611, a regenerative heat exchanger 612, and a low temperature heat exchanger 613. Is an external heating and cooling alpha type Stirling engine. Since the working gas is heated and cooled by a heat exchanger provided outside, isothermal expansion and isothermal compression cannot be expected.
As the high temperature side bellows piston 601, the type shown in FIG. 4 without fins is used. When the object with fins shown in FIG. 3 is used, heat is dissipated from the fins in the high temperature side bellows piston, and the thermal efficiency is lowered.
Replacing the bellows piston with a piston / cylinder is the same as a normal Stirling engine. The drive device is the same as in [Embodiment 5], and the phase of the high temperature side bellows piston is advanced by 90 ° with respect to the low temperature side bellows piston.

FIG. 7 is a schematic view showing a method of constructing a gamma-type Stirling engine using a bellows piston. To construct a gamma-type Stirling engine with a bellows piston, two bellows pistons replace the double-acting piston, one bellows piston replaces the output piston, and a total of three bellows pistons. is necessary.
The high temperature side bellows piston 701 and the low temperature side bellows piston 702 are connected with a high temperature heat exchanger 711, a regenerative heat exchanger 712, and a low temperature heat exchanger 713 interposed therebetween. The output bellows piston 703 is connected in parallel with the low temperature side bellows piston 702 as shown in FIG. The high temperature side bellows piston 701 and the low temperature side bellows piston 702 have a complementary relationship with a phase difference of 180 °. The phase of the output bellows piston 703 is delayed by 90 ° with respect to the high temperature side bellows piston 701. These are realized by a crankshaft, but the crankshaft itself is a known technique and will not be described in detail.
This example is structurally the same as that of the [alpha] type Stirling engine of [Embodiment 6] with one bellows piston added.

The fact that the function of a double-acting piston can be realized by two bellows pistons having a phase difference of 180 ° as described above constitutes a Stirling engine corresponding to a rotating swash plate type double-acting four-cylinder Stirling engine. It means you can do it.
A Stirling engine equivalent to a rotary swash plate type double-cylinder four-cylinder Stirling engine has four high temperature side bellows pistons arranged at equal intervals on one side of the rotary swash plate and faces the opposite side of the rotary swash plate. It can be configured by deploying four low temperature side bellows pistons. Each high temperature side bellows piston is connected to the adjacent low temperature side bellows piston with a regenerative heat exchanger in between. It may be connected to either the right side or the left side, but if the connection is reversed, the rotation is reversed. These bellows pistons may be any of circulation type, fin type, or external heating / cooling type, but when using the external heating / cooling type shown in FIG. It is necessary to install an exchanger and a low-temperature heat exchanger. In the case of the circulation type, the temperature or pressure fluctuation pattern differs for each bellows / piston. Therefore, a circulation pump and a heat exchanger are required for each bellows / piston, and the circulation pump and heat exchanger are shared. I can't do it.

In the case of a rotary swash plate type double-acting four-cylinder Stirling engine using a conventional double-action cylinder, force in both directions is alternately applied to the piston rod, so the gap between the shoe at the tip of the piston rod and the rotary swash plate If this adjustment is performed incorrectly, noise may be generated. However, if the high temperature side bellows piston and the low temperature side bellows piston are placed facing each other on both sides of the rotating swash plate as shown in this example, the high temperature side bellows piston Although the force acting on the piston rod and the piston rod of the low-temperature side bellows piston has a difference in strength, they both push the rotating swash plate, and there is no gap between the rotating swash plate and the shoe. There is no fear of occurrence.

It is sectional drawing which shows a double bellows piston. It is a partial sectional view showing a liquid circulation type bellows piston. It is a partial sectional view showing a fin type bellows piston. It is a partial cross section figure which shows the bellows piston which does not have a heating-cooling mechanism. It is the schematic diagram which comprised the internal heating cooling alpha type Stirling engine. It is the schematic diagram which comprised the external heating cooling type alpha type Stirling engine. It is the schematic diagram which comprised the gamma type Stirling engine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Outer bellows 102 Inner bellows 103 Bellows lower surface 110 Displacer piston 111 Cylinder 112 Fin 113 Power piston 114 Power piston rod 115 Liquid seal chamber 116 Low temperature space 117 High temperature space 118 Displacer piston rod 120 Liquid outlet 121 Liquid return port 201 Bellows 203 Bellows lower surface 210 Vent 211 211 Cylinder 213 Piston 214 Piston rod 215 Liquid sealed chamber 216 Gas space 220 Liquid outlet 221 Liquid return port 301 Bellows 311 Cylinder 312 Fin 313 Piston 315 Liquid sealed chamber 316 Gas space 401 Bellows 411 Cylinder 413 Piston 415 Liquid sealed chamber 416 Gas Space 501 High temperature side bellows piston 502 Low temperature side bellows piston 511 External high temperature heat source 5 2 regenerative heat exchanger 513 external cold heat source 531 connecting rod 532 crankshaft 533 flywheel 601 high temperature side bellows piston 602 cold side bellows piston 611 high temperature heat exchanger 612 regenerative heat exchanger 613 cold heat exchanger
701 High temperature side bellows piston 702 Low temperature side bellows piston 703 Output piston 711 High temperature heat exchanger 712 Regenerative heat exchanger 713 Low temperature heat exchanger

Claims (2)

Enclose the working gas inside, increase the volume by heating and expanding the working gas, constitute a series of cycles to cool and compress the expanded working gas back to its original volume, A working gas consisting of a cylinder fitted with a piston used in a so-called Stirling engine, which takes out the difference between the work amount obtained at the time of expansion and the work amount required at the time of compression as an output, is enclosed. Used as a volume variable member in place of a volume variable member, wherein a bellows is accommodated in a cylinder fitted with a piston, and is used over the entire region formed by the wall surface of the bellows, the inner surface of the cylinder and the upper surface of the piston. A volume varying member having a structure in which a liquid substance is filled and a working gas is sealed inside the bellows, The expansion movement of the bellows due to the expansion of the working gas sealed inside is transmitted to the piston through the liquid filling material to push out the piston, and the compression force for pushing the piston from the outside is applied to the liquid filling material. A series of cycles for compressing the working gas that is transmitted to the bellows through the bellows and sealed in the bellows, and the work amount obtained when the working gas is expanded and the working gas is compressed A variable volume member used for a Stirling engine that takes out the difference from the required work as an output. A substance that is liquid under operating conditions filled over the entire area formed by the wall surface of the bellows housed in the cylinder fitted with the piston, the inner surface of the cylinder, and the upper surface of the piston, is transferred to the outside of the area and the cylinder. The volume fluctuation used in the Stirling engine according to claim 1, wherein the working gas enclosed in the bellows is heated or cooled by circulating between the high temperature heat exchanger or the low temperature heat exchanger provided. Element.

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