JPS6140451A - Stirling engine - Google Patents

Abstract

PURPOSE:To prevent a displacer from slightly vibrating due to the lateral flex phenomenon of a displacer rod, by making the coupling section between the displacer and the displacer rod movable in the rotational and horizontal directions. CONSTITUTION:A displacer cap 19 is secured to a displacer skirt 20, and the inner race 25 of a lubricationless spherical bearing is attached to a displacer rod 24 by means of a fixture 26. Further, the outer diameter of outer race 27 of the lubricationless spherical bearing is made less than the bore diameter of a spherical bearing holder 20a to allow the spherical bearing to go away in the thrust direction. There are provided horizontally movable lubricationless annular flat bearings 28, 29, and therefore when the displacer rod 24 flexes in accordance with the reciprocating motion thereof, the inner race 25 of the special bearing is inclined and the flat bearings 28, 29 are moved in the horizontal direction, thereby the flex of the rod may be absorbed by the coupling section.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a Stirling engine, and particularly to its piston structure.

[Prior art]

A conventional example of a Stirling engine is shown in FIG. 1, and its configuration and operation will be explained.

Figure 1 is a configuration diagram of a displacer type cooling engine, which is one of the typical configuration examples of a Stirling engine. In Figure 0, l is an expansion cylinder, 2 is a heater tube, 3 is a regenerator, 4 is a tala tube, 5 is an air supply piston generally called a displacer, 6 is a displacer rod, 7 is a tenth seal for sealing the sliding gap between the expansion cylinder 1 and the rondro, 8 is a compression cylinder, and 9 is the compression cylinder 8 and the expansion cylinder. 10 is a power piston, 11 is a power piston ring, and 12 is a second communication pipe for sealing the sliding gap between the compression cylinder 8 and the power piston rod 11.
13 is a first connecting rod for converting the rotational force of the crankshaft into reciprocating motion of the displacer 5; 14;
15 is a second connecting rod for converting the reciprocating motion of the power piston 10 into rotational force of the crankshaft, and 15 is a displacer 5.
and a crankshaft for reciprocating the power piston 10 with a predetermined phase difference and at the same time obtaining rotational force, 16.1
7 is a main bearing of the crankshaft 15; 100 is a crankcase for holding the components 1 to 17 at predetermined positions; and 18 is a buffer chamber.

In the Stirling engine configured in this way,
If the heater tube 2 is continuously heated with a burner or the like, and the cooler tube 4 is continuously cooled with water or the like, pressure fluctuations occur within the cylinder, which causes the power piston 10 to move up and down, allowing power to be extracted.

By the way, generally when operating a Stirling engine at high efficiency and high output, the expansion cylinder 1° and the compression cylinder 8
It is a well-known fact that hydrogen and helium are used as the working gas sealed inside. Therefore, it can be said that the most important consideration in putting the Stirling engine into practical use is the sealing of hydrogen and helium.

However, in the conventional Stirling engine, the displacer 5 and the displacer rod 6 are completely fixed, and therefore, the lateral deflection of the loft 6 that occurs when the displacer rod 6 moves up and down causes the displacer itself to minutely vibrate. . As a result, the piston ring seal used in the displacer 5 comes into irregular contact with the expansion cylinder and the displacer ring land, making it impossible to maintain a stable seal over a long period of time, and causing a significant decrease in engine thermal efficiency. .

[Summary of the invention]

This invention was made to eliminate the above-mentioned conventional drawbacks, and by configuring the connecting portion between the displacer and the displacer rod connected thereto so that both can freely move in the rotational direction and the horizontal direction. To provide a Stirling engine that can prevent minute vibrations of a displacer and stabilize the sealing performance of a piston ring over a long period of time.

[Embodiments of the invention]

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

Fig. 2 shows a sectional view of the main parts of a Stirling engine according to an embodiment of the present invention, and Fig. 0 shows the connection structure of the displacer and displacer rod shown in Fig. 1II. , 20 is the displacer skirt, 19 is this displacer skirt 2
The displacer cap 20a fixed at 0 is a spherical bearing holder. 21.22 is a displacer sliding holding ring, 23 is a piston ring, 24 is a displacer rod, 25 is an inner ring of a non-lubricated spherical bearing, and 26 is an inner ring of this spherical bearing! 25 to the displacer rod 24; 27 is an outer ring of a non-lubricated spherical bearing; the outer diameter of this outer ring is smaller than the hole diameter of the spherical bearing holder 20a; 9 I am now able to escape. 28 and 29 are horizontally movable non-lubricated annular plane bearings. 30 is an opening in the center of the displacer skirt, and the displacer rod 24
The hole diameter is at least 211111 times larger than the diameter of the hole, and the inner ring 25 of the non-lubricated spherical bearing does not come into contact with the inner ring 25 under any circumstances.

Reference numeral 31 denotes a fixing fitting for fixing the outer ring 27 of the non-lubricated spherical bearing to the displacer skirt 20.

Here, this fixture 31 is the outer ring 27 of the spherical bearing.
is fixed so as to be movable in the axial direction by approximately 20 μm or more and 50 μm or less. 32.33 is the displacer cap 19. This is an O-ring seal provided on each of the fixing fittings 31.

The operation of the thus constructed connection structure between the displacer and the displacer rod will be explained using FIG. 3.

In FIG. 3, the same reference numerals as in FIG. 2 indicate the same functional members. The central axis of the expansion cylinder and the central axis of the displacer are indicated by line segment A-A. The rod center axis at the time of maximum axial vibration of the rod due to the reciprocating movement of the displacer rod is shown on line 0-A. At this time, the inner ring 25 of the spherical bearing has the center axis A
-A, while at the same time the outer ring 27 of the spherical bearing can move horizontally β relative to the non-lubricated planar annular thrust bearing 28,29.

According to the embodiments T and -C, the deflection of the rod due to the reciprocating movement of the displacer rod can be absorbed by the connecting portion with the displacer, and the displacer central axis always reciprocates up and down the central axis of the expansion cylinder. becomes possible. As a result, irregular contact of the piston ring with the cylinder and piston ring land, which has been a problem in the past, can be completely eliminated, the sealing performance of the piston ring seal can be improved, and the engine thermal efficiency can also be improved. Therefore, it is a very effective means for putting the Stirling engine into practical use.

FIG. 4 is a diagram showing another embodiment of the present invention, showing only the connecting portion between the displacer and the rod. In the figure, the same reference numerals as in FIG. 2 indicate the same functional members. 34 is a displacer rod fixed to the outer ring 27 of the non-lubricated spherical bearing, 35 is a piston pin inserted through the displacer skirt 20, 36 and 37 are fittings for preventing piston pin removal, 25 is an inner ring of the non-lubricated spherical bearing, Reference numeral 39 denotes a horizontally movable lubricant-free bearing bushing provided at a penetrating portion between the piston pin 35 and the inner ring 25. Further, in such a configuration, the penetrating direction of the piston pin 35 is the same direction as the axial deflection direction of the displacer rod 34.

In this embodiment, when axial vibration of the displacer rod 34 occurs, the outer ring 27 of the non-lubricated spherical bearing tilts.
In addition, the inner ring 25 is displaced in the axial direction of the piston pin, and it goes without saying that the same effects as in the above embodiment can be obtained.

In addition, in the above embodiment, a Stirling engine (composed of a displacer, a power source, and a stone) is used.
Although a so-called gamma-type Stirling engine is shown, it goes without saying that the same effects as in the above-mentioned embodiments can also be obtained in a so-called beta-type Stirling engine having a displacer and a power piston in one cylinder.

〔Effect of the invention〕

As described above, according to the present invention, the connecting portion between the displacer and the displacer rod, which was conventionally completely fixed, is configured with a non-lubricated spherical bearing and a horizontally movable non-lubricated bearing, so that the displacer can always operate stably. This has the effect of improving the sealing performance of the piston ring seal.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a typical configuration example of a conventional Stirling engine, FIG. 2 is a sectional configuration diagram of essential parts of a Stirling engine according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a diagram showing another embodiment of the present invention. 5... Displacer, 6, 24.34... Displacer rod, 10... Working piston, 25.27
...Inner ring and outer ring of non-lubricated spherical bearing, 28.29...
Non-lubricated annular plane bearing, 35... Piston pin, 39
...Lubricant-free bearing bushing. -The same reference numerals in the figures indicate the same or corresponding parts. Agent Ken Hayase - Figure 1 Figure 2 - Figure 3 ↑ Figure 4

Claims (3)

[Claims] (1) In a Stirling engine in which the reciprocating movement of the displacer causes pressure fluctuations in the cylinder and the pressure fluctuations are applied to the power piston to obtain output, the displacer and the displacer rod are movable in the horizontal direction using non-lubricated spherical bearings. A Stirling engine characterized by being connected using non-lubricated bearings. (2) The horizontally movable non-lubricated bearing is installed inside the skirt of the displacer, and the non-lubricated spherical bearing is installed between the horizontally movable non-lubricated bearing and the side surface of the distal end of the displacer rod. A Stirling engine according to claim 1, characterized in that: (3) The non-lubricated spherical bearing is fixed to the tip of the displacer rod, and the non-lubricated spherical bearing is fitted between the piston pin of the displacer via the horizontally movable non-lubricated bearing. The Stirling engine according to claim 1, characterized in that: