JPH0213147B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piston drive mechanism for reciprocating an air supply piston and a power piston within one cylinder with a predetermined phase difference in a Stirling engine.

A schematic diagram of a conventional piston drive mechanism is shown in FIG. In the figure, 1 surrounded by a dashed line indicates the crankshaft, 1a is the crank main shaft, 1b is the first crank arm, 1c is the first crank pin, 1d is the second crank arm, and 1e is the second crankshaft. Crank pin, 2 is the first piston, 3 and 4 are the first and second piston pins fixed to the first piston 2, 5 is the second piston, 6 is the center shaft of the first piston 2 A second part that can reciprocate as a bearing
a piston rod of the piston 5; 7 is a third piston pin provided at the end of the piston rod 6;
8 is a first connecting rod that links the first piston pin 3 and the first crank pin 1c; 9 is a second connecting rod that links the second piston pin 4 and the first crank pin 1c; 10 is a third link linking the third piston pin 7 and the second crank pin 1e.
The connecting rod 11 is a cylinder in which the first piston 2 and the second piston 5 reciprocate. As can be seen from FIG. 2 showing the side view, the central axis of the second crank pin 1e and the first crank pin 1
The central axis of c has the crank main shaft 1a as the origin,
Since there is a θ degree deviation in the rotational direction of the crank shaft 1a, when the crank shaft 1a rotates in the direction of the arrow in the figure, the second piston 5, e.g., the air supply piston, is out of phase with the first piston 2, e.g., the power piston, by θ degrees. This results in an advanced reciprocating motion. FIG. 3 shows a front sectional view and a side view of the actual crankshaft 1.

Since the piston drive mechanism of the conventional Stirling engine is configured as described above, the crankshaft portion 1 has a complicated configuration, which is difficult to work with, and furthermore, the total length L of the crank pin of the crankshaft portion 1 is extremely long. . For this reason, the first, second and third connecting rods 8,
In order to operate 9 and 10 smoothly over a long period of time, the diameter of the crank main shaft 1a must be increased, which results in increased friction loss at the crank bearing, which reduces the mechanical efficiency of the Stirling engine. It was hot.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional crank pins, and a flange portion whose side surface is larger than the outer diameter of the side surface of the crank arm is provided between the two first crank pins. The object of the present invention is to provide a piston drive mechanism for a Stirling engine that has high mechanical efficiency and can be easily machined by having a second crank pin fixedly attached to the second crank pin.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 4A, reference numeral 12 is a flange portion provided at the center of the two first crank pins 1c, and whose side surface has the same outer diameter as, for example, the side surface of the crank arm 1b. 13, as shown in the side view in FIG. 4B, is a position where the circular shape of the side surface advances by θ degrees in the rotational direction of the crank main shaft 1a from the center axis of the first crank pin 1c, with the central axis of the crank main shaft 1a as the origin. is the central axis, the radius is larger than that which can encompass the first crank pin 1c, and a hole is bored inside in the shape of the flange part 12, for example, by press-fitting or shrink-fitting, etc.
This is a second crank pin fixed to the flange portion 12.

In the Stirling engine piston drive mechanism configured in this manner, when the crank main shaft 1a rotates in the direction of the arrow, the air supply piston 5 connected to the second crank pin 13 is connected to the first crank pin 1c. It performs a reciprocating motion that is θ degrees ahead of the power piston 2 in phase. In this embodiment, since the second crank arm is not provided, the total length L of the piston pin of the crank main shaft 1a can be made shorter than in the conventional piston drive mechanism, and the rigidity of the crank main shaft 1a is increased, resulting in Crank main shaft 1a
can be made thinner, increasing mechanical efficiency. Also,
In the manufacturing process, the crank arm 1b, the first
If the crank pin 1c and the flange 12 are manufactured at the same time, the second crank pin 13 cut out from the shape of the flange 12 is passed through the crank main shaft 1a, and fixed to the flange 12 by press fitting or shrink fitting. You can easily create a piston drive mechanism for a Stirling engine.

Furthermore, the second crank pin 13 can be made of aluminum alloy or the like, which makes it lighter than if it were made of iron or the like, and further reduces the unbalanced force caused by the center spacing.

In addition, the outer diameter of the crank arm 1b and the flange portion 12
Machining time can be shortened by making the outer diameters of the two parts the same and making both center axes the same. That is, when manufacturing the crank arm 1b, the first crank pin 1c, and the collar 12, first the collar 12 and the crank arm 1 are manufactured.
It can be manufactured by simply finishing the outer diameter of b into a cylindrical shape at the same time, and then cutting out the side surface of the crank arm 1b and the first crank pin 1c, which can significantly shorten the machining time of the piston drive mechanism.

As described above, according to the present invention, two first
A flange portion whose side surface is larger than the outer diameter of the side surface of the crank arm is provided between the crank pins, and a second crank pin is fixed to this flange portion, thereby increasing machine efficiency and improving workability. This has the effect of providing a piston drive mechanism of a Stirling engine that can be used.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing the piston drive mechanism of a conventional Stirling engine, Fig. 2 is a side view of Fig. 1, and Fig. 3A is an actual crank in the piston drive mechanism of a conventional Stirling engine. FIG. 3B is a front sectional view showing the shaft, and FIG. 3B is a side view of FIG. 3A. FIG. 4A is a front sectional view showing one embodiment of the present invention, and FIG. 4B is a side view of FIG. 4A. In the figure, 1 is the crankshaft, 1a is the crank main shaft, 1b is the first crank arm, 1c is the first crank pin, 2 is the first piston, 3 is the first piston pin, 4 is the second Piston pin, 5
is the second piston, 7 is the third piston pin, 8
is the first connecting rod, 9 is the second connecting rod, and 10 is the third connecting rod.
connecting rod, 11 is the cylinder, 12 is the collar, 13
indicates the second crank pin. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. First and second pistons configured to be able to reciprocate within a cylinder, first and second piston pins formed on the first piston, and the second piston.
a third piston pin formed on the piston;
first, second, and third connecting rods each having one end connected to the first, second, and third piston pins, and connected to the other end of each of the first, second, and third connecting rods; A piston drive mechanism for a Stirling engine that operates the first and second pistons with a predetermined phase difference,
The total length of the crank pin of the crankshaft, which is composed of a crank main shaft, a crank arm, and a first and second crank pin, is at least two widths of the bearing at the end of the first connecting rod, and a width of the third bearing. The width shall be greater than or equal to the sum of the width of one bearing at the end of the connecting rod, and the width of the two first bearings shall be at least
The third connecting rod is disposed between the crank pins, has a side surface including the side shape of the crank arm, and has a width equal to or larger than the width of the bearing at the end of the third connecting rod. A piston drive mechanism for a Stirling engine, characterized in that a second crank pin serving as a bearing at the end of a connecting rod is fixed. 2. A piston drive mechanism for a Stirling engine according to claim 1, wherein the second crank pin is made of an aluminum alloy. 3. Claim No. 3, characterized in that the shape of the side surface of the crank arm is a circular shape circumscribing the first crank pin and the crank main shaft, and the center of the circular shape of the side surface of the flange is made to coincide with the center of the crank arm. A piston drive mechanism for a Stirling engine according to item 1 or 2.