JPH01280668A - Multicylinder type stirling engine - Google Patents

Abstract

PURPOSE:To prevent an eccentric load from being exerted on the bearing of a crank shaft, by a method wherein two sets, each formed by a pair of expansion pistons and a compression piston, are provided, and each piston is coupled, in particular phase relations, to a crank shaft. CONSTITUTION:A stirling engine S is provided with two compression pistons 2 and 3 driven by a crank shaft and four expansion pistons 4-7. Four expansion cylinders 32-35 horizontally extending in a reverse direction to each other and two compression cylinders 30 and 31 extending in a vertical direction are formed in series to a housing. Connecting rods 13, 10 and 9 of the expansion pistons 4 and 5 and the compression piston 2, respectively, are coupled to a plurality of crank pins 14 and 15 mounted to a crank shaft. This constitution causes reciprocation of the expansion pistons 4 and 5 in an iso-phase and reciprocation of the compression piston 2 in a further delay phase than that in which the expansion pistons 4 and 5 is reciprocated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a multi-cylinder Stirling engine.

(Prior art) Conventionally, this type of Stirling engine was
There is one shown in Japanese Patent No. 9252.

This one has a guide piston that moves up and down vertically, one expansion piston with a diaphragm, and a bank angle of 45 to 90.
Two compression pistons each with a guide piston and a diaphragm are connected to one crankshaft each having an independent crank bin, which changes the volume of two compression chambers in the same phase within a range of By reducing fluctuations in the centers of mass of the two compression pistons, mechanical vibrations are prevented from occurring and lubricating oil is prevented from entering the working fluid.

(Problem to be Solved by the Invention) However, in the conventional configuration described above, the expansion piston is arranged between the recompression pistons whose volume changes in the same phase, and each piston is independent of one crankshaft. Since each crank pin connected to each compression piston is connected to a crank pin, a force from each compression piston acts simultaneously, tending to tilt the crankshaft from its axis of rotation. That is, a coupled moment acts around an axis perpendicular to the crankshaft.

Therefore, this moment becomes an uneven load on the hair ring that supports both ends of the crankshaft, and becomes a force that shakes the hair ring, worsening the durability of the bearing and creating a gap between the hair ring and the housing. If so, there is a problem that noise and vibration will be generated.

Therefore, the technical problem of the present invention is to prevent unbalanced loads from acting on the hair ring that supports the crankshaft.

[Structure of the invention]

(Means for Solving the Problems) The technical means taken to solve the above-mentioned technical problems is to change the configuration of the multi-cylinder Stirling engine to a pair of expansion pistons that reciprocate in opposition to each other in the horizontal direction. and one reciprocating compression piston that reciprocates in the vertical direction, and the expansion pistons of each set are operatively connected to the crankshaft so as to reciprocate in the same phase with each other, It acts on the crankshaft so that each compression piston reciprocates with a predetermined phase difference with respect to each pair of expansion pistons, and so that the axis of each pair of expansion pistons is in the same plane as the axis thereof. It was connected to.

(Operation) According to the above means, the forces acting on the crankshaft from the expansion piston cancel each other out, and only the force from the compression piston acts on the crankshaft. Since the compression piston is of a double-acting type, the force from the compression piston has a small variation range, and as a result, an unbalanced load does not act on the hair ring that supports the crankshaft.

(Example) Hereinafter, as an example of the present invention, an example in which the present invention is used as a prime mover will be described based on the drawings.

In Figures 1 and 2, the Stirling engine S is 1
It has two compression pistons 2, 3 and four expansion pistons 4.5, 6.7 driven by a main crankshaft 1,
The first portions are horizontally opposite to each other and extend in opposite directions.
The expansion cylinder 32 and the second expansion cylinder 33, and the third expansion cylinder 34 and the fourth expansion cylinder 35 are each provided with a housing formed in series. The housing further includes a first compression cylinder 30 and a second compression cylinder extending vertically.
A compression cylinder 31 is formed in series. The axes of the first expansion cylinder 32 and the second expansion cylinder 33 and the third expansion cylinder 34 and the fourth expansion cylinder 35 are concentric, and the axes of the first compression cylinder 30 and the second compression cylinder 31 are concentric with each other. The center is perpendicular to the respective axes of the first expansion cylinder 32 and the second expansion cylinder 33, and the third expansion cylinder 34 and the fourth expansion cylinder 35. Although shown in separate cross sections in FIG. 1 for easy understanding, each set is integrally formed in series.

A first expansion piston 4 (second expansion piston 5) is fitted into the first expansion cylinder 32 (second expansion cylinder 33) so as to be slidable in the axial direction. 2 expansion piston 5) is slidably inserted into the same cylinder as the guide piston 18 (guide piston 2).
0) via a rod 24 (rod 26). The guide piston 18 (guide piston 20)
is connected to a crank mechanism C which will be described later, and when the crank mechanism C is driven, the first expansion piston 4 and the guide piston 18 and the second expansion piston 5 and the guide piston 20 are reciprocated in the same phase. It has become so.

Also, the third expansion cylinder 34 and the fourth expansion cylinder 35)
A third expansion piston 6 (fourth expansion piston 7) is fitted into the cylinder so as to be slidable in the axial direction. It is connected to a movably fitted guide piston 21 (guide piston 23) via a rod 27 (rod 29). The guide piston 21 (guide piston 2
3) is connected to a crank mechanism C which will be described later, and when the crank mechanism C is driven, the third expansion piston 4 and the guide piston 21 and the fourth expansion piston 7 and the guide piston 23 are in the same phase with each other. The first expansion piston 4 and the second expansion piston 5 reciprocate with a phase difference of 180 degrees. In addition, each expansion piston 4
．． A piston ring R is attached to the outer periphery of the pistons 5, 6, and 7.

A first compression piston 2 (second compression piston 3) is fitted into the first compression cylinder 30 (second compression cylinder 31) so as to be slidable in the axial direction. The second compression piston 3) is connected via a rod 25 (rod 28) to a guide piston 19 (guide piston 22) which is slidably fitted into the same cylinder. The guide piston 19 (guide piston 22
) is connected to a crank mechanism C which will be described later, and when the crank mechanism C is driven, the first expansion piston 4 and the second
The expansion piston 5 (the third expansion piston 6 and the fourth expansion piston 7) is reciprocated with a phase difference of 90 degrees. First compression piston 2 and guide piston 19
(The second compression piston 3 and the guide piston 22) are provided with a rod 25 (rod 28
) partition member 68 (partition member 69) sliding on the outer peripheral surface of
are provided in the first compression cylinder 30 (second compression cylinder 31), and an upper compression space 52 and a lower compression space 53 (upper A compression space 54 and a lower compression space 55) are formed.

The upper compression space 52 of the first compression cylinder 30 is connected to the first heat radiator 36 (second heat radiator 37), first heat storage 44 (second heat storage 45), and first heater head 48 (second heater head 49). A first expansion space 32a defined between the tip of the first expansion cylinder 32 (second expansion cylinder 33) and the first expansion piston 4 (second expansion piston 5)
(the second expansion space 33a). As a result, the working fluid such as helium or hydrogen is transferred to the first radiator 36 (
When passing through the second radiator 37), the cooling fluid 40 (41
) is isothermally compressed while exchanging heat with the first heat storage device 44 (second heat storage device 45), and is further cooled by passing through the first heat storage device 44 (second heat storage device 45).
8 (second heater head 49), the first
By pushing down the expansion piston 4 (second expansion piston 5), it expands isothermally and generates power. Similarly, the upper compression space 54 of the second compression cylinder 31 also has a third heat radiator 38 (fourth heat radiator 39), a third heat accumulator 46 (second heat accumulator 47), and a third heater head 5.
0 (the second heater head 51), the third expansion cylinder 34 (the second expansion cylinder 35) has a third expansion defined between its tip end and the third expansion piston 6 (the fourth expansion piston 7). It communicates with the space 34a (fourth expansion space 35a). In addition, the upper compression space 5 of the No. 1 compression cylinder 30
2 communicates with the lower compression space 55 of the second compression cylinder 31, and the lower compression space 53 of the first compression cylinder 30 communicates with the lower compression space 55 of the second compression cylinder 31.

In FIG. 1, the crank space Cs located on the right side of the guide piston 18.21 and on the left side of the guide piston 20.23 is formed by each diaphragm 57, 58, 60.61 disposed in each expansion cylinder 32-35. Each buffer space 70-7 defined between each expansion piston 4-7
3 through respective purifiers 63, 64, 66, 67. In addition, the crank space Cs is for each compression cylinder 3.
Each diaphragm 56, 59 disposed at 0.31 mm communicates with each buffer space 74, 75 defined between each partition member 68, 69 via each purifier 62, 65. This prevents contaminated fluid in the crank space Cs from flowing into the working space and causing the engine to stop, reduces the burden on each diaphragm due to pressure fluctuations, and reduces the burden on each piston. By equalizing the back pressure acting on the piston and the pressure inside the crank space Cs, stable reciprocating operation of each piston can be obtained. Each of the diaphragms 56 to 61 has its inner circumferential edge hermetically fitted to the outer circumferential surface of each rod 24 to 29, and its outer circumferential edge is hermetically fixed to the inner circumferential wall of each cylinder 30 to 35. Thus, the reciprocating motion of each rod 24-29 is followed, and the volume of each buffer space 70-75 is substantially constant regardless of the reciprocating motion of each rod 24-29. Further, as shown in Fig. 2, if the buffer spaces 70, 72 and 71, 73, which have a phase difference of 180 degrees from each other, are made to communicate with each other, it is possible to further reduce pressure fluctuations. It is.

Next, the crank mechanism C will be explained. In FIG. 2, a crank mechanism C includes a crankshaft 1 driven by a drive source such as an electric motor (not shown) and rotatably supported by a housing via a pair of bearings 76 and 77. The crankshaft 1 includes a first crank pin 14, and the first crank pin 14 is 180 degrees from each other.
The second crank pin 14 has a phase difference of .degree. and is located on both sides of the first crank pin 14. the third crank pins 15, 15, the fourth crank pin 16 in the same phase as the first crank pin 14, and the fourth crank pin 15,
The fifth crank pin 16 is located on both sides of the fourth crank pin 16 and has a phase difference of 180° from each other. It has sixth crank pins 17, 17. As shown in FIG.
The connecting rod 9 of the first compression piston 2 and the connecting rod 10 of the second expansion piston 5 are rotatably connected.

The connecting rod 10 of the second expansion piston 5 is bifurcated and is rotatably connected to each first crank pin 15, and the connecting rod of the first expansion piston 4 is rotatably connected to the first crank pin 14. 13 and the connecting rod 9 of the first compression piston 2 swing within the bifurcated portions 10a and 10b. As a result, the first expansion piston 4,
The axes of the second expansion piston 5 and the first compression piston 2 are on the same plane, and the first expansion piston 4 and the second expansion piston 5 reciprocate in the same phase, and the first compression piston 2 is connected to each expansion piston. 4.5, it can be arranged to reciprocate with a phase difference of 90° behind that of 4.5. Note that the connecting rod 9 of the first compression piston 2 is rotatably connected to the connecting rod 13 of the first expansion piston 4, which is rotatably connected to the first crank pin 14. In addition, 3rd. Fourth expansion piston 6
．． 7 connecting rod 13.11 and the connecting rod 12 of the second compression piston 3 are similarly connected to the fourth crank pin 16 and the fifth
．． It is rotatably connected to the sixth crank pins 17, 17.

With the above configuration, the forces acting on the crankshaft 1 from each set of three pistons (two expansion pistons, one compression piston) are applied to each of the three pistons on the crankshaft 1 as a resultant force.
In addition, the forces from the two expansion pistons are equal and in phase, so they cancel each other out, and each compression piston 2.3
Only the force from is acting on the crankshaft 1. The force from each compression piston 2.3 is equal to
By being driven with a phase difference of 80 degrees, it forms a couple, and although it does not become an excitation force that pushes the crankshaft 1 in one direction, it acts as a force that tries to tilt the crankshaft 1 from its rotation axis. It acts on the crankshaft 1. However, in this embodiment, each compression piston 2
, 3 are double-acting types, so the variation in the way the force is applied is smaller than that of normal single-acting types, and as a result, the force is transferred to the bearing 76°77 that supports the crankshaft 1.
This prevents the bearing from acting as an unbalanced load, becoming a force that shakes the bearing 76, 77, deteriorating the durability of the bearing, and causing noise and vibration if there is a gap between the bearing 76, 77 and the housing. .

As described above, according to the present invention, it is possible to provide a multi-cylinder Stirling engine in which the movable parts as a whole are balanced and the movement of the entire center of gravity is extremely small and the vibrations are low.

〔Effect of the invention〕

According to the present invention, the forces acting on the crankshaft from the expansion piston cancel each other out, so that only the force from one compression piston acts on the crankshaft, and the force from the compression piston causes the compression piston to move backward. Since it is a molded type, the range of variation in the way force is applied is small, so there is no unbalanced load acting on the hair ring that supports the crankshaft, and no noise or vibrations are caused. Further, according to the present invention, a diaphragm is disposed between each piston and the crank space in which the crankshaft is disposed to define a buffer space, and between each buffer space and the crank space. Since the purifier is installed, the back pressure acting on each piston and the pressure in the crank space are equalized, ensuring stable operation of each piston and preventing engine damage due to oil etc. entering the working space. Stops, etc. can be reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of a multi-cylinder Stirling engine according to the present invention, FIG. 2 is a cross-sectional view of FIG. 1, and FIG. 3 is a schematic diagram of the crank mechanism in the present invention. . ■... Crankshaft, 2... First compression piston, 3... Second compression piston, 4... First expansion piston, 5... Second expansion piston, 6... Third expansion Piston, 7... Fourth expansion piston, 8, 9, 10, 11
,12.13 ・ ・Conrod, 14...1st
Crank bottle, 15...2nd. 3rd crank pin, 1
6...4th crank pin, 17...5th crank pin. 6th crank pin, 18-23... Guide piston, 52
, 54... Upper compression space, 53.55... Lower compression space, 56-61... Diaphragm, 70-75...
- Buffer space, 62-67...purifier.

Claims (2)

[Claims] (1) In a multi-cylinder Stirling engine, each set consists of a pair of expansion pistons that reciprocate in opposition to each other in the horizontal direction, and a double-acting compression piston that reciprocates in the vertical direction. The expansion pistons are operatively connected to a crankshaft so as to reciprocate in phase with each other, and each compression piston is reciprocated with respect to each pair of expansion pistons with a predetermined phase difference; A multi-cylinder Stirling engine in which a pair of expansion pistons are operatively connected to the crankshaft so that their axes lie on the same plane. (2) A diaphragm is disposed between each of the pistons and a crank space in which the crankshaft is disposed to define a buffer space, and a diaphragm is provided between each of the buffer spaces and the crank space. Claim 1 in which a container is provided
The described multi-cylinder Stirling engine.