JPS5985451A - Stirling engine - Google Patents

Abstract

PURPOSE:To miniaturize an engine and to prevent lubricating oil from adhering to a piston ring, by intercommunicating the back space of an expansion piston and the back space of a compression piston through a surge tank. CONSTITUTION:An expansion piston 125 is disposed within an expansion cylinder 115 connected to a heating tube 231. A back space 133 is formed between the expansion piston 125 and an expansion rod 121 connected thereto by means of a pin 131. The diameter of the expansion rod 121 is made smaller than that of the expansion piston 125 to reciprocate it within a lower expansion cylinder 117. A back space 173 is formed between the compression piston 165 and a compression rod 161. The two back spaces 133 and 173 are intercommunicated through a surge tank chamber 255. This prevents deterioration in function resulting from adhesion of lubricating oil in a crank chamber 101 to an expansion piston ring 127 and a compression ring 167.

Description

Detailed Description of the Invention C. Technical Field of the Invention The present invention relates to a Stirling engine in which an expansion cylinder and a compression cylinder are respectively attached with a heater and a cooler and are connected to each other by a regenerator. This invention relates to improvements in expansion cylinders, compression cylinders, and ring parts.

[Technical Background of the Invention and Problems Therewith] Generally, the above-mentioned Stirling engine has a thermal cycle section that reciprocates a piston in an expansion cylinder etc. using thermal energy, and a crank mechanism section that extracts the output as rotational force. ing. By the way, the working fluid of the Stirling engine is He, N2. A non-condensable gas such as N2 is used and the working fluid is filled and sealed within the cylinder sections and their connections.

That is, FIG. 1 is a schematic diagram of the Stirling engine, in which an expansion cylinder 2 and a compression cylinder 3 are protruded from the top wall of a machine chamber 1, and the expansion cylinder 2 is heated by a high-temperature heat source. The compression cylinder 3 is connected to a heating unit 4 that is cooled by a cold source, and the compression cylinder 3 is connected to a cooler 5 that is cooled by a cold source.
are connected to each other via a regenerator 6.

On the other hand, an expansion piston 7 and a compression piston 8 are disposed in the expansion cylinder 2 and compression cylinder 3 so as to be able to reciprocate, respectively, and both pistons 7.8 are connected to the machine chamber 1 by means of connecting rods 9 and 10, respectively. The pistons 7.8 are connected to a crankshaft 11 disposed horizontally therein, so that both pistons 7.8 reciprocate with a predetermined phase difference.

By the way, the expansion cylinder 2. Compression cylinder 3° heating section 4. A working fluid such as He, N2, or N2 is sealed in the cooler 5, the regenerator 6, and the piping connecting them. It is sealed by 13.

When the working fluid is heated by the high-temperature heat source in the heating section 4, it expands and the expansion piston 7 is pressed down, causing the crankshaft 11 to rotate. Still above expansion piston 7
When the fluid moves to the upward stroke, the working fluid passes through the heating section 4 and is transferred to the regenerator 6, where it gives heat to the heat storage material filled in the regenerator 6, and flows to the cooler 5 where it is cooled. , is compressed along with the upward stroke of the compression piston 8. The working fluid compressed in this way flows to the heating section 4 side, and on the way, the temperature rises while taking heat from the heat storage material in the regenerator 6, and flows into the heating section 4, where it is heated again to a high temperature. It is heated and expanded by a heat source.

By the way, in this type of Stirling engine, the compression piston 8 of the expansion piston 7 is provided with a cross paddle in the stroke movement mechanism, thereby transmitting the reciprocating motion of the piston to the crankshaft 11 as rotational motion. 8. Generally speaking, oil countermeasures are taken to prevent lubricating oil from the crank chamber 1 from adhering to the piston rings 12 and 13 attached to the expansion piston 7 and reducing their functionality. If the crosshead method is used, the mechanism will be large and structurally complex.

[Purpose of the invention]

In view of these points, it is an object of the present invention to provide a Stirling engine that can minimize the size of the engine, maintain sufficient engine performance, and prevent lubricating oil from adhering to piston rings attached to the pistons. With the goal.

[Summary of the invention]

The present invention provides a Stirling engine in which an expansion cylinder and a compression cylinder are respectively attached with a heater and a cooler, and both are connected to each other by a regenerator.
An expansion piston back space is formed between the expansion piston and the expansion rod, and a compression piston back space is formed between the compression piston and the compression rod. It is characterized in that it is configured so that it communicates through a surge tank.

C Embodiments of the invention] Examples of the invention will be described below with reference to FIGS. 2 to 2. In FIG. 2, the names and functions of the main mold components of the present invention will be explained below.

The crankcase 101 holds the crank mechanism and the entire engine, and contains working gas, lubricating oil, and the like.

The crank chamber 103 is a space inside the crankcase, and contains a crank mechanism, working gas, lubricating oil, and the like.

The crankshaft 105 is a part of a crank mechanism that converts the reciprocating motion of the expansion piston and the compression piston into rotational motion, and extracts shaft output.

The crankbin 107 rotatably couples the crankshaft and the expansion connecting rod.

The expansion connecting rod 109 connects the crank M and the expansion rod and converts the reciprocating motion of the expansion piston into rotational motion of the crankshaft.

The compression connecting rod 111 connects the crankshaft and the compression rod, and converts the reciprocating motion of the compression piston into rotational motion of the crankshaft.

Lubricating oil 113 is oil for the purpose of lubrication and cooling, and is sealed in the crankcase and supplied to each sliding portion by a lubrication mechanism.

The expansion cylinder 115 contains a reciprocating expansion piston,
This also forms an expansion chamber between the expansion cylinder and the expansion piston.

The l11 tension lower cylinder 117 fixes the expansion side bearing and restricts the direction of reciprocating movement of the expansion rod.

The expansion side peg ring 119 is fixed within the expansion lower cylinder to achieve smooth reciprocating movement of the expansion rod.

The inflation rod 121 reciprocates within the inflation lower cylinder.

Expansion rod bin 123 connects the expansion rod and expansion connecting rod.

The expansion piston 125 reciprocates within the expansion cylinder and forms an expansion chamber between the JI+ piston and the expansion cylinder. Preventing leakage of working gas 0 Expansion rod piston ring 129 is installed in the groove of the expansion rod to prevent lubricating oil from migrating to the back of the expansion piston.

Expansion coupling bin 131 couples the expansion piston and expansion rod.

The expansion piston back space 133 is a space formed between the back surface of the expansion piston and the lower expansion cylinder.

Thermal shield plate 135 is disposed inside the expansion piston to prevent heat radiation from the high temperature source of the expansion piston head.

The support rod 137 is a rod that fixes the heat shield plate to the lower part of the expansion piston.

The passage pipe 139 is a passage pipe that communicates with the surge tank in order to reduce pressure pulsations when the expansion piston reciprocates in the space behind the expansion piston.

The expansion piston back passage 141 is the gas inside the passage tube.

A cooling water inlet pipe 143 supplies water for cooling the expansion piston rings.A cooling water outlet pipe 145 discharges water for cooling the expansion piston rings.

Cooling water 147 is supplied into the cooling jacket and expansion cylinder to cool the expansion piston ring.

The expansion chamber 149 is formed between the expansion piston and the expansion cylinder, and is a space in which the working gas expands. ○ Heater inlet space 1
51 is a space connecting the expansion chamber and the heater.

The expansion piston internal space 153 is a space formed within the expansion piston.

The compression cylinder 155 contains a reciprocating compression piston, and forms a compression chamber between the compression cylinder and the compression piston.

The compression lower cylinder 157 fixes the compression side bearing and restricts the direction of reciprocating movement of the compression rod.

The compression side ring 159 is fixed within the compression lower cylinder to realize smooth reciprocation of the compression rod.

The compression rod 161 reciprocates within the compression lower cylinder.

Compression rod pin 163 connects the compression rod and expansion connecting rod.

The compression piston 165 reciprocates within the compression cylinder and forms a compression chamber between the compression piston and the compression cylinder.

The compression piston ring 167 is mounted within the groove of the compression piston to prevent leakage of working gas within the compression chamber.

A compression rod piston ring 169 is mounted within a groove in the compression rod to prevent lubricating oil from migrating to the back of the compression piston.

A compression coupling bin 171 couples the compression piston and compression rod.

The compression piston back space 173 is a space formed between the back surface of the compression piston and the compression lower cylinder.

The passage pipe 179 is a passage pipe connected to a surge tank and serves to reduce pressure pulsations when the compression piston reciprocates in the space behind the compression piston.

The compression chamber 189 is formed between the compression piston and the compression cylinder and is a space in which one working gas is compressed.

The cooler inlet space 191 is a space connecting the compression chamber and the cooler.

The cooler/cooler bellows 201 forms the outer shell of the cooler.
Absorbs deformation caused by thermal expansion of the entire engine.

A cooler compression side flange 203 connects the compression cylinder and the cooler.

The cooler regeneration side flange 205 connects the regenerator and the cooler.

The cooling pipe 207 is a pipe that connects the compression chamber and the regeneration chamber,
C to cool the working gas.

The cooling tube inner rod 209 is inserted into the cooling tube to reduce the dead space of the working gas within the cooling tube.The cooling tube support plate 211 supports the cooling tube in an appropriate arrangement.

The seal groove 213 is a groove in which an O-ring is installed to prevent leakage of working gas.

An O-ring 215 is installed within the seal groove to prevent leakage of working gas.

The cooling water inlet pipe 217 supplies water for cooling the working gas in the cooler.

1 cooling water 219 is supplied into the cooler bellows and the cooling pipe to cool the working gas inside the cooler.

The cooling water outlet pipe 221 discharges water for cooling the working gas in the cooler.

The cooling chamber 223 is a space between the cooling pipe and the rod inside the cooling pipe, and cools the working gas.

The regenerator case 225 connects the cooler and the heater and holds a regeneration filler therein.

A fill 227 is retained within the regenerator case and performs the heat regeneration function.

The regeneration chamber 229 is a space through which the working gas in the regenerator passes.

The heating tube 231 is located within the combustor and heats the working gas as it passes therethrough.

The heating chamber 233 is a space between the heating tube and the rod inside the heating tube, and heats the working gas.

A heating tube inner rod 235 is inserted into the heating tube to reduce the dead space of the working gas within the heating tube. A heater flange 237 connects the expansion cylinder and the heater.

Heater support plate 239 supports the heating tubes in the proper arrangement.

The duct 241 keeps the high temperature combustion gas inside and is insulated from the outside air.

The combustion chamber 243 contains high-temperature combustion gas and heats the working gas in the heater.

The combustor 245 mixes fuel and air and ignites them to obtain high-temperature combustion gas.

Fuel 247 is fuel supplied to the combustor.

The exhaust pipe 249 discharges the exhaust gas after the high temperature combustion gas has undergone heat exchange with the heater.

The exhaust gas 251 is low-temperature combustion gas after heat exchange with the heater.

The surge tank 253 has an appropriate volume, has both ends communicating with the expansion piston back space and the compression piston back space, and damps pressure pulsations.

0 The surge tank chamber 255 is a space inside the surge tank where pressure pulsations are attenuated. - The 0 communication pipe 257 is a pipe that communicates the surge tank chamber and the crank chamber.

The O-water cooling jacket 259 cools the expansion cylinder and prevents the expansion piston ring from overheating.

Furthermore, with reference to FIG. 2, the configuration system of the Stirling engine of the present invention will be schematically explained. crank case 10
1 has an expansion cylinder 115 and a compression cylinder 1
55 protrudes, one end of a plurality of heating tubes 231 of the heater 4 is connected to the upper part of the expansion cylinder 115, and the other end of the heating tube 231 is connected to the regenerator 6. Further, a cooler 5 cooled by cooling water is connected to the compression cylinder 155, and the cooler 5 is connected to the regenerator 6.

On the other hand, the expansion cylinder 115 and the compression cylinder 15
5, an expansion piston 125 and a compression piston 165 are disposed so as to be able to reciprocate, and both histones 1
25 and 165 are connecting rods 109, respectively.
, 111 to the crankshaft 105 so that both pistons reciprocate with a predetermined phase difference, for example, 900 degrees.

Therefore, the expansion piston 125 is connected to the expansion rod 121 by the expansion rod pin 123, and an expansion piston back space 133 is formed in the expansion cylinder 115 between the expansion piston 125 and the expansion rod 121. The expansion rod 121 has a smaller diameter than the expansion piston 125 and reciprocates within the lower expansion cylinder 117. The upper surface of the sliding surface of the expansion long piston ring 129 in the expansion lower cylinder 117 on the expansion chamber 149 side is as follows:
It is located closer to the expansion chamber 149 than the lower surface of the sliding surface of the expansion piston ring 127 of the expansion piston 125 on the crank chamber 103 side.

The compression piston 165 is connected to the compression rod 161 by a compression rod 163.
5(!: A compression piston back space 173 is formed in the compression cylinder 155 between the compression rods 161.

As with the expansion piston 125, the compression rod 1
61 is formed to have a smaller diameter than the compression piston 165;
It reciprocates within the compression lower cylinder 157. Also, the compression front piston ring 169 of this compression lower cylinder 157
The upper surface on the compression chamber 189 side of the sliding surface of the crank chamber 103 is the sliding portion of the compression piston ring 167 of the compression piston 165.
It is located on the compression chamber 189 side from the lower side surface.

The expansion piston back space 113 and the compression piston back space 173 are connected to a surge tank chamber 255 in the surge tank 253 via an expansion piston back passage 1411 and a compression piston back passage 181, respectively. It communicates with the upper part of the chamber 103 via a communication pipe 257.

Further, a cooling jacket 301 is installed around the expansion cylinder 115 at a position where the piston ring 127 of the expansion piston 125 is movable. The cooling jacket 301 is also provided with a cooling water inlet pipe 143 for cooling the expansion piston 1j ring 125 and a cooling water outlet pipe 145 for discharging the cooling water.

FIG. 3 shows another embodiment of the invention. An on-off valve mechanism 305 that opens and closes based on the differential pressure between the compression chamber 189 and the surge tank 2530 is installed between the passage pipe 179 that communicates with the passage 303 that communicates with the compression chamber 189 and the surge tank 253 (!). has a valve spring 309 on the back, and is opened and closed by the differential pressure between the back space 311 communicating with the compression chamber 189 and the space 313 communicating with the surge tank 253 and the compression piston back space 73.

The operation of each on-off valve 307 will be briefly explained below. The pressure in the compression chamber 189 fluctuates due to the reciprocating movement of the compression piston 165 and the piston 125. This compression chamber 1 (to)
When the internal pressure is higher than the internal pressure of the surge tank 255, the on-off valve 307 is closed due to the pressure difference, and high pressure gas does not move to the surge tank 255 side.

However, when the pressure in the compression chamber 189 is lower than the pressure in the surge tank 255, the on-off valve 307 opens due to the pressure difference, and the gas in the surge tank 255 moves to the compression chamber 189. Due to this action, the pressure on the surge tank 255 side can be constantly maintained at the lowest pressure on the compression chamber 189 side.

FIG. 4 shows another embodiment of the invention. compression piston 1
The head 65 has a communication hole 405 that communicates with the compression chamber 189 and the compression piston back space 173, and an on-off valve 401 covers the upper part of the communication hole 405. This on-off valve is a valve stop port 40
3 and is fixed to the compression piston 165. In this case as well, the opening/closing valve function is similar to that explained in the embodiment shown in FIG.
9 lowest pressure values can be held.

〔Effect of the invention〕

As explained above, in the present invention, an expansion piston back space is formed between the expansion piston and the expansion rod, and a compression piston back space is formed between the compression piston and the compression rod, and the expansion piston back space is formed between the expansion piston and the expansion rod. Since the rain space between the piston back space and the compression piston back space is configured to communicate through the surge tank, the shapes of the expansion piston and compression piston can be made smaller, and lubricating oil can be prevented from adhering to the piston ring. It can provide an extremely reliable and high performance Stirling engine.

Furthermore, an on-off valve is provided between the passage communicating with the compression chamber and the passage communicating with the surge tank, which opens and closes depending on the differential pressure between the compression chamber and the surge tank. Only force acts on the piston ring, keeping the piston ring in good working order, extending the life of the piston ring, and at the same time reducing the amount of leakage from the piston ring. Furthermore, since it is possible to further prevent oil from adhering to the piston rings, it is possible to provide an extremely reliable Stirling engine.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a Stirling engine, FIG. 2 is a partially sectional side view of the Stirling engine of the present invention, and FIG.
The figure is a partial sectional view showing another embodiment of the Stirling engine of the invention, and FIG. 4 is a longitudinal sectional view of the compression piston portion of the Stirling engine of the invention. 103... Crank chamber, 115... Expansion cylinder,
117... Expansion lower cylinder, 125... Expansion piston, 127... Expansion piston ring, 133... Expansion piston back space, 147... Cooling water, 149... Expansion chamber, 155...
・Compression cylinder, 157... Compression lower cylinder, 16
5... Compression piston, 167... Compression piston ring, 173... Compression piston back space, 189... Compression chamber, 253... Surge tank. Agent: Patent attorney Noriyuki Chika (and 1 other person) Figure 1

Claims (6)

[Claims] (1) In a Stirling engine in which an expansion cylinder and a compression cylinder are each attached with a heater and a cooler, and are connected to each other by a regenerator, the space between an expansion piston having a piston ring and an expansion rod having a piston ring An expansion piston back space is formed between the compression piston having the piston ring and a compression rod having the piston ring, and a rain space between the expansion piston back space and the compression piston back space is formed between the compression piston and the compression rod having the piston ring. A Stirling engine characterized by being configured to communicate through a surge tank. (2) The Stirling engine according to claim 1, wherein the diameter of the expansion rod is smaller than the diameter of the expansion piston, and the expansion rod is configured to reciprocate within the lower expansion cylinder. (3) The Stirling engine according to claim 1, wherein the diameter of the compression rod is smaller than the diameter of the compression piston, and the compression rod is configured to reciprocate within the compression lower cylinder. (4) The Stirling engine according to claim 1, wherein the surge tank chamber and the upper part of the crank chamber are configured to communicate with each other. (5) The Stirling engine according to claim 1, wherein a cooling jacket is provided at a position of the piston ring movable portion of the expansion piston in the expansion cylinder. (6) Claim 1 characterized in that an on-off valve that opens and closes depending on the differential pressure between the compression chamber and the surge tank is installed between the passageway communicating with the compression chamber and the passageway communicating with the surge tank. Stirling engine as described in section. (The passage connecting the force compression chamber and the back space of the compression piston,
2. The Stirling engine according to claim 1, further comprising an on-off valve provided on the compression piston and arranged on the compression piston head to open and close the passage.