JPH06100156B2 - Stirling engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a Stirling engine, and more particularly to a Stirling engine using a crankcase as a buffer tank.

[Conventional technology]

Figure 3 shows the Stirling engine (St.
FIG. 9 is a cross-sectional view showing a schematic structure of a conventional displacer type Stirling engine described in irling Engines (Clarendon Press, Oxfourd 1980)) and the like. In the figure, 1 is a crankcase, 2a and 2b are bearings held by the crankcase 1, 3 is a crankshaft rotatably supported by these bearings 2a and 2b, and 3a is a power piston which is a part of the crankshaft 3. The crank pin portion 3b for the air supply piston. 4a and 4b are connecting rods for power pistons, which are connected to the crosshead 5 and convert the reciprocating linear motion of the crosshead 5 into the rotary motion of the crankshaft 3. 6 is a power piston rod, and 7 is a power piston (power piston). Reference numeral 8 is a connecting rod for the air feeding piston, and 9 is a rod for the air feeding piston, which is connected to the connecting rod 8 for the air feeding piston. 10 is an air feeding piston. Reference numeral 11 is a cylinder liner that guides reciprocating sliding movements of the air supply piston 10 and the power piston 7, 12 is a silane block fixed to the crankcase 1, 13 is a burner and heat exchanger of the Stirling engine, and 14 is a crankcase. It is oil that is stored in the lower part of 1 to lubricate the moving part in the crankcase.

Further, 15 is a rod seal for preventing oil in the crankcase 1 from entering the piston portion, and 16 is a rod seal.
This is a holder for fixing 15 to the crankcase 1. Reference numeral 17 is a buffer tank, and 19 is a communication pipe for ventilating the piston lower space 18 (buffer space) and the buffer tank 17. Reference numeral 20 is an operating space composed of the power piston 7, the cylinder liner 11, the cylinder block 13, and the like.

Next, the operation will be described.

The Stirling engine is a type of external combustion and is a highly efficient heat engine. The displacer type Stirling engine causes a pressure fluctuation in the cylinder by a displacer (air supply piston) 10 as a cycle, and causes the pressure fluctuation to act on the power piston 7, and the output thus obtained is externally output by the crankshaft 3. I try to take it out. Usually, in this type of engine, a rod seal 15 is provided to prevent the infiltration of the oil 14 into the operating space 20 for the purpose of improving efficiency and reliability, and fulfills its role. Since this rod seal 5 is provided, the space below the piston
The volume of 18 becomes small and loss due to pressure fluctuation occurs. To prevent this, a buffer tank 17 is usually provided.

However, in the Stirling engine equipped with such a buffer tank 17, the buffer tank 17 has been an obstacle to downsizing and cost reduction of the engine. Therefore, a hot gas engine having a structure in which such a buffer tank can be omitted is proposed in U.S. Pat. No. 3,810,634 and Japanese Patent Publication No. 58-31465. These proposed hot gas engines use a crankcase as a buffer tank, and connect the buffer space under the power piston and the crankcase with a pipe so that gas can flow in and out between the crankcase part and the buffer space. In particular, an oil separation mechanism is provided in the pipe that connects the crankcase portion and the buffer space so that the oil in the crankcase does not enter the lower part of the power piston.

[Problems to be Solved by the Invention]

However, the hot gas engine proposed above does not require a buffer tank, so the engine can be downsized to some extent as compared with a conventional one having a buffer tank, but in the pipe communicating between the crankcase part and the buffer space. Since an oil filter or an oil separation mechanism that combines an oil filter and a float valve mechanism is formed, there is a problem that the communication pipe itself is complicated and large, and the engine cannot be sufficiently downsized.

The present invention has been made to solve the above problems, and can prevent oil from entering the buffer space for a long period of time, and can maintain good efficiency and reliability of the engine for a long period of time. , To obtain a Stirling engine that can make the engine itself smaller than conventional ones.

[Means for Solving the Problems]

A Stirling engine according to the present invention is a Stirling engine in which a pressure fluctuation generated in a cylinder is acted on a power piston, and an output obtained by the fluctuation is taken out by a crankshaft to a buffer space below the power piston. And a communication pipe for ventilating connection between the crankcase and the internal space of the crankcase, and an opening formed in the crankcase for connecting the internal space of the crankcase and the internal space of the communication pipe. The first air permeability allows gas to pass from the inner space to the inner space of the communication pipe, and the second air permeability allows gas to pass from the inner space of the communication pipe to the inner space of the crankcase. Oil that adheres and absorbs oil mist with small particle size generated inside the crankcase The sponge for separation is provided in the opening of the crankcase, and the sponge for oil separation is shut off so that oil mist having a large particle size generated in the internal space of the crankcase does not come into contact with the sponge for oil separation. And, the oil-separating plate member for collecting and collecting the oil mist having the large particle size on the surface thereof and flowing down the collected oil to the bottom of the crankcase, and the opening for the crankcase are attached. An oil escape groove formed on a flange for fixing the oil separating sponge and one end of the communication pipe to the opening, and allowing the oil retained in the oil separating sponge to escape to the bottom of the crankcase. It is characterized by having and.

[Action]

According to the present invention, since the buffer space and the internal space of the crankcase are ventilated and connected by the communication pipe, the crankcase can be used as a buffer tank, and the engine can be used as compared with the conventional engine. Can be small. Further, an oil separation sponge, an oil separation plate member, and an oil relief groove are formed in an opening of the crankcase for connecting the internal space of the crankcase and the internal space of the communication pipe. Since the means is provided, the inflow and outflow of gas performed through the communication pipe between the buffer space and the internal space of the crankcase is influenced by the oil mist generated inside the crankcase for a long period of time. Without receiving the oil mist (without causing the oil mist generated inside the crankcase to enter the buffer space), the efficiency and reliability of the engine can be favorably maintained for a long period of time. Further, since the oil separating means is not provided inside the communication pipe, the communication pipe can be configured by a thin pipe, and the engine can be further downsized.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 2 and FIG. 2 show an embodiment of the present invention, and FIG.
It is the figure which looked at the inside of the crankcase 1 which crossed the crankshaft 3 at right angles to the axial direction in the conventional apparatus of the figure. In the figure, 19 'is a communication pipe for connecting the piston lower space 18 and the internal space of the crankcase 1 in aeration manner, and 21 is an oil separation for preventing the oil 14 in the crankcase 1 from being introduced into the communication pipe 19'. It is a vessel. As described above, the apparatus of this embodiment is not provided with the buffer tank unlike the conventional apparatus, and the function thereof is substituted for the crankcase 1.

FIG. 1 is a view for explaining the details of the oil separator 21. In the figure, 19 'is the above-mentioned communication pipe, 22 is a crank chamber flange attached to the opening of the crankcase 1, and One end of the communication pipe 19 'is fixed to one side thereof, and the internal space of the communication pipe 19' and the internal space of the crankcase 1 are connected by a through hole formed in a predetermined portion thereof. 14 'is an oil mist which is an atomized or granular oil generated in the crankcase 1, 25 is a first sponge that absorbs the oil mist 14', and 27 is a first sponge having a smaller density than the first sponge 25. , 26 are the first sponge 25 and the second sponge
The wire mesh 24 for positioning the sponge 27 is a cover (shielding plate) provided on the first sponge 25 so as not to directly contact the oil mist 14 ′, and the lower portion thereof is notched.
23 is formed in a portion of the crank chamber flange 22 located below the lower end of the second sponge 27.
An oil relief groove for letting the oil staying at 25, 27 escape to the inside of the crankcase 1. Here, the oil separator (21) including the first sponge 25, the wire netting 26, the second sponge 27, and the cover 14 is the communication pipe 1 of the crank chamber flange 22.
The one end of 9'is fixed to the side opposite to the fixed side, that is, the side along the internal space of the crankcase 1. The first sponge 25 and the second sponge 27 are
It has both the air permeability for allowing gas to pass from the internal space of the crankcase 1 to the internal space of the communication pipe 19 'and the air permeability for allowing gas to pass from the internal space of the communication pipe 19' to the internal space of the crankcase 1. Is.

Next, the operation will be described.

The displacer (air supply piston) 10 causes a pressure fluctuation in the cylinder, and this pressure fluctuation is applied to the power piston 7, and the output thus obtained is taken out from the crankshaft 3 to the outside. And in the engine of this embodiment,
By the time the gas containing the oil mist 14 'generated in the crankcase 1 passes through the communication pipe 19', the oil mist with a large particle size in this oil mist 14 'is covered.
When the oil mist having a small particle size in the remaining oil mist 14 'passes through the first and second sponges 25, 27, it is separated from the gas by being attached and collected on the surface of the It is separated from the gas by being attached and absorbed by the first and second sponges 25, 27. The oil mist 14 '(oil) attached and collected on the cover 24 flows down to the bottom of the crankcase 1 due to its own weight, and the oil mist 14' attached to the first and second sponges 25, 27 is When the amount of adhesion increases, the weight of the oil drops to the oil escape groove 23 due to its own weight, and the oil adheres to the bottom of the crankcase 1 through the oil escape groove 23.

Here, the sponges 25 and 27 are gas flows, that is, gas flows from the buffer space 8 side to the crankcase 1,
In addition, it is necessary to select a material that is less likely to cause pressure loss (small pressure loss) when the gas flows from the crankcase 1 side to the buffer space 8 side, and that the oil mist 14 'is easily attached. Further, it is better to select the first sponge 25 having a higher density than that of the second sponge 27 for better oil separation effect.

In such a Stirling engine of this embodiment, the internal space of the crankcase 1 and the lower portion (buffer space) 18 of the power piston 7 are communicated with each other by a communication pipe 19 ', and the crankcase 1 is used as a buffer tank. Therefore, the engine can be downsized. In addition, the first and second sponges 2 for adsorbing and absorbing the oil mist having a small particle size at the opening of the crankcase 1, that is, the boundary between the internal space of the crankcase 1 and the internal space of the communication pipe 19 '.
5,27 and the first and second sponges 25,27 are prevented from being directly applied with the oil mist having a large particle diameter, and the oil mist having a large particle diameter is adhered and collected on the surface of the oil mist. A plate-shaped cover 24 for allowing oil to flow down to the bottom of the crankcase 1 and an oil relief groove 23 for allowing oil retained in the first and second sponges 25, 27 to escape to the bottom of the crankcase 1 are provided. Therefore, the inflow and outflow of gas performed between the lower portion (buffer space) 18 of the power piston 7 and the internal space of the crankcase via the communication pipe 19 'is generated in the empty space inside the crankcase for a long period of time. The oil mist 14 ′ is stably operated without entering the lower part (buffer space) 18 of the power piston 7, and as a result, the efficiency and reliability of the engine are kept good for a long time. Further, unlike the conventional device, an oil separator (oil separation mechanism) is not provided inside the communication pipe 19 ', so that the communication pipe 1'
9'can be made thinner and the engine can be made even smaller.

Although the sponge is divided into two in the above embodiment, the number may be one. The type of sponge is not limited, and an oil filter or the like may be attached instead of the sponge. However, in any case, it is preferable not to use a type that increases the pressure loss.

〔The invention's effect〕

As described above, according to the Stirling engine according to the present invention, in the Stirling engine in which the pressure fluctuation generated in the cylinder is acted on the power piston, and the output obtained by this is taken out to the outside by the crankshaft, A communication pipe for connecting the buffer space below the power piston and the internal space of the crankcase to each other by ventilation, and an opening formed in the crankcase for connecting the internal space of the crankcase and the internal space of the communication pipe. First ventilation that is provided and allows gas to pass from the internal space of the crankcase to the internal space of the communication pipe, and second ventilation that allows gas to pass from the internal space of the communication pipe to the internal space of the crankcase. Oil mist with small particle size that is generated inside the crankcase The oil separating sponge that adheres and absorbs, and the oil separating sponge that is provided in the opening of the crankcase and that does not come into contact with the oil mist having a large particle size generated in the internal space of the crankcase The sponge is shielded, and the oil mist having a large particle diameter is attached and collected on the surface of the sponge, and the collected oil is allowed to flow down to the bottom of the crankcase. The oil separating sponge attached to the opening is formed on a flange for fixing one end of the communication pipe to the opening, and the oil retained in the oil separating sponge is transferred to the bottom of the crankcase. An oil relief groove is provided to allow the engine to maintain its efficiency and reliability for a long time. Rutotomoni, there is an effect that can be largely smaller than the engine itself conventional.

[Brief description of drawings]

FIG. 1 is a diagram showing in detail an oil separation mechanism of a Stirling engine according to an embodiment of the present invention, FIG. 2 is a partial sectional view of a Stirling engine according to an embodiment of the present invention, and FIG. It is sectional drawing of the oil separation mechanism of a displacer type Stirling engine which uses a buffer tank. 1 is a crankcase, 18 is a piston lower space, 19 'is a communication pipe, 21 is an oil separator, 25 is a first sponge, and 27 is a second sponge. The same reference numerals in the drawings indicate the same or corresponding parts.

Front page continuation (72) Inventor Tetsuya Honda 8-1-1 Tsukaguchi Honcho, Amagasaki City, Hyogo Prefecture Sanryo Electric Co., Ltd. Central Research Laboratory (72) Inventor Joh Mu 1-1-1, Tsukaguchi Honcho, Amagasaki City, Hyogo Prefecture Sanryo Electric Co., Ltd. Central Research Laboratory (72) Inventor Tadahiro Yoshida 8-1-1 Tsukaguchi Honcho, Amagasaki City, Hyogo Prefecture Sanryo Electric Co., Ltd. Central Research Laboratory (56) Reference JP-A-58-158353 (JP, A) ) U.S.A. 57-59911 (JP, U) U.S.A. 60-3213 (JP, U) JP-B-58-31465 (JP, B2) US Patent 3810634 (US, A)

Claims (1)

[Claims] 1. A Stirling engine in which a pressure fluctuation generated in a cylinder is applied to a power piston, and an output obtained by the fluctuation is taken out to the outside by a crankshaft, wherein a buffer space below the power piston and a crankcase. A communication pipe for ventilating and connecting the internal space of the crankcase and an opening formed in the crankcase for connecting the internal space of the crankcase and the internal space of the communication pipe to each other. A first breathability that allows gas to pass into the internal space of the communication pipe;
An oil-separating sponge that has a second air permeability that allows gas to pass from the internal space of the communication pipe to the internal space of the crankcase, and that attaches and absorbs oil mist having a small particle size generated inside the crankcase. And so as to prevent the oil mist having a large particle diameter generated in the internal space of the crankcase from coming into contact with the oil separating sponge provided in the opening of the crankcase,
The oil separation sponge is shielded, and the oil mist having a large particle size is attached and collected on the surface thereof,
The plate member for oil separation that allows the collected oil to flow down to the bottom of the crankcase, the sponge for oil separation attached to the opening of the crankcase, and one end of the communication pipe are connected to the opening. A Stirling engine, comprising: an oil escape groove formed on a flange for fixing the oil to the oil separation sponge and allowing oil retained in the oil separation sponge to escape to the bottom of the crankcase.