JPS62203968A - Lubrication mechanism of stirling engine - Google Patents

Abstract

PURPOSE:To obtain a simple, inexpensive lubrication mechanism utilizing pressure variance within a crank case by arranging a partition plate in a bottom part of the crank case to divide the said part into an oil reservoir part and an upper space above the said plate and providing the said plate with both an oil return valve and an oil supply valve. CONSTITUTION:When a power piston connected via a rod 14 to a crosshead 13 reciprocates within a cylinder 16, pressure within a crank case 1 varies. Therefore, dividing the inside of the crank case 1 with a partition plate 30 into a part for holding lubricant oil 21 and a gas space, and providing the partition plate 30 with an oil return valve 32 and an oil supply valve 33, pumping action is performed. Namely, the oil return valve 32 is opened when the pressure in the crank case 1 is higher than its means pressure to drop the lubricant oil 21 into the bottom part of the crank case bottom cover. When the pressure in the crank case 1 is lower than the mean pressure on the other hand, the oil supply valve 33 is opened to raise the lubricant oil 21 via an oil supply pipe 34.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an oil supply mechanism for a Stirling engine, and more particularly to an improvement in a method for supplying oil to an output extraction mechanism.

[Conventional technology]

FIG. 7 is a diagram showing the basic structure of a conventional 1-cylinder, 2-piston type Stirling engine described in, for example, Japanese Patent Laid-Open No. 60-212660. In the figure, 1 is a crankcase, and all the parts of the Stirling engine are assembled based on this part. 2 is a flange fixed to a hole machined in crankcase 1 with a fastening part such as a bolt, 3 is a bearing housing fastened and fixed to crankcase 1 in the same way as flange 2, and 4 is fastened and fixed to crankcase 1. The flange, 5 is the main bearing fixed to the bearing howling 3, 6 is the main bearing fixed to the flange 2, 7 is the crankshaft, which is rotatably held by the main bearings 5 and 6, and the Stirling engine was generated. It transmits power to the outside. Reference numeral 8 denotes a mechanical seal attached to the crankshaft 7, which seals off gas within the crankcase 1. 9 and 10 are balance weights for balancing the rotation of the crankshaft 7, and are fixed to the crankshaft 7.

In addition, 11 and 12 are power piston stove throats connected to the crankshaft 7 by bearings, and 13 is a crosshead that is connected to the power piston stove throats 11 and 12. A rod 14 and a power piston 15 are connected. Further, the outer periphery of the crosshead 13 is fitted to the inner periphery of the cylinder 16 so as to be able to slide back and forth with a bearing function. 17 is a conloft for a displacer piston, and is rotatably connected to the crankshaft 7 via a bearing. 18 is a piston pin,
19 is a displacer rod, which is connected to the displacer connecting rod 17 using the piston pin 1 as a contact point, and is also connected to the cross〉・de 13゜power piston rod 1
4. It passes through the power piston 15 and is fixedly connected to the displacer piston 20.

21 is the moving part of the Stirling engine accumulated at the bottom of crankcase 1? vJ is lubricating oil for sliding, 22 is a lip seal. 23 is an oil pump provided at the end of the crankshaft 7, and 24 is an oil supply hole provided at the bottom of the crankcase 1. In addition, the combustor part of the Stirling engine,
Explanation of structural parts such as the heat exchanger part will be omitted.

Next, the operation of the entire engine will be explained.

In a so-called crankshaft Stirling engine with one cylinder and two pistons arranged in series, as shown in FIG. Power piston rod 14. Rad to the cross 13. The power is transmitted to the power piston connecting rods 11 and 12. The rotational work is then outputted to the outside by the crankshaft 7.

In addition, part of this rotational work is transferred to the displacer piston 2.
0, induces reciprocating motion, and operates as a Stirling engine.

To explain the refueling operation in such an engine,
As the oil pump 23 rotates, the crankcase 1
The lubricating oil 21 at the bottom passes through the oil supply hole 24 to the oil pump 23.
The oil is sent to the crankshaft 7. from this oil pump 23 through an oil supply passage (not shown). Connecting rods 11 and 12 for power pistons, connecting rods for displacer pistons 17° piston vias 18. Crosshead 13th grade R?
Lubricating oil 21 is supplied to %iJ.

The oil supply mechanism as described above is used in conventional Stirling engines, but as another example, for example,
There is also a lubrication mechanism as shown in the figure.

That is, as used in internal combustion engines, power piston connecting rods 11 and 12. An oil splasher 25 is provided at the lower part of the connecting rod 17 for the displacer piston. According to this, the oil splasher 25 hits the lubricating oil surface as the crankshaft 7 rotates, and the lubricating oil 21 is blown away and each oil supply section is refilled.

[Problem that the invention seeks to solve]

In the case of a conventional Stirling engine oiling mechanism, for example, the seventh
In the example shown in the figure, since the oil supply pump 23 is provided, there is a problem that the structure is complicated and the cost is high.
In the example shown in the figure, there was a problem that the necessary amount of oil supply could not be obtained when the engine became high speed.

This invention was made to solve the above-mentioned problems, and it is an object of the present invention to provide an oil supply mechanism for a Stirling engine that is inexpensive and can obtain a sufficient amount of oil supply.

In order to solve the above problem, it is sufficient to realize an oil pump with a simple structure, but the inventor of the present invention
As a result of intensive research, they discovered that this could be achieved by utilizing a phenomenon unique to the Stirling institution.

In the Stirling engine, gas is sealed in the crankcase 1, as explained in the example of FIG.
The crank chamber constituted by 5 is a sealed container. Since the power piston 15 reciprocates during engine operation, the volume of the crank chamber changes periodically, and pressure fluctuations occur in the crank chamber accordingly. Therefore, by performing the pumping action using this pressure fluctuation,
It is thought that an oil pump can be realized with a simple structure.

[Means for solving problems]

Therefore, the Stirling engine oil supply mechanism according to this invention is as follows:
A crankcase partition plate is provided at the bottom of the crankcase to partition the lubricating oil reservoir and its upper space, and a valve mechanism for an oil return valve and an oil supply valve is provided on the slope of the partition, and the valve mechanism causes the above-mentioned pressure fluctuation in the crankcase. lubricating oil is supplied to each part using

[Effect]

In this invention, pressure fluctuations accompanying the reciprocating motion of the power piston generated within the crankcase are utilized to
The lubricating action is generated by a 1i1 valve mechanism. That is, when the pressure inside the crankcase is higher than the average pressure inside the crankcase, the oil return valve opens and returns the lubricating oil falling from each part to the bottom of the crankcase, and when the pressure inside the crankcase is lower than the above average pressure. The oil supply valve opens to suck up lubricating oil through the oil supply pipe and supply it to each part.

〔Example〕

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

In FIG. 1, 30 is a crankcase partition plate provided at the bottom of the crankcase and partitions the lubricating oil reservoir and the upper space of the crankcase; 31 is a crankcase bottom cover;
7 is an oil return hole provided in the crankcase partition plate 30, and the lower opening of this oil return hole 37 is provided with a W
An oil return valve 32 is installed to return the slipped oil to the lubricating oil reservoir. 34 is an oil supply pipe for forming an oil supply hole 38, and an oil supply valve 33 for supplying lubricating oil from the ifJ oil reservoir to each oil supply part is attached to the upper opening of 2. 35 is a cover provided to cover the oil supply valve 33; 36 is a oil supply hole formed in the crankcase 1, which is led to the center of the crankshaft 7, through which lubricating oil is supplied to each oil supply part. It has become.

Next, the operation will be explained.

During engine operation, the power piston 15 reciprocates within the cylinder 16, causing the volume within the crankcase 1 to change, and the pressure within the crankcase 1 to change accordingly.
It fluctuates as shown in the figure.

Therefore, in this embodiment, the inside of the crankcase 1 is divided into a part where lubricating oil 21 is stored and a gas space by a partition plate 30, and an oil return valve 32 and an oil supply valve 33 are connected to the partition plate 30.
are provided, and these two valves perform the pumping action by utilizing the above pressure fluctuations.

That is, for example, lubricating oil 21' that falls after finishing lubrication of the movement mechanism section first accumulates on the crankcase partition plate 30. In this state, the pressure inside the crankcase 1 is higher than the average pressure inside the crankcase 1 (X shown in Fig. 2).
range), the oil return valve 32 opens as shown in FIG. 4, and the lubricating oil 21 falls to the bottom of the crankcase bottom cover 31. Next, during the time period when the pressure inside the crankcase 1 is lower than the above average pressure (range Y shown in FIG. 2), the pressure in the lubricating oil reservoir is higher than the pressure in the gas section inside the crankcase 1, so as shown in FIG. As shown in the figure, the oil supply valve 33 opens and the oil supply pipe 3
4, the lubricating oil 21 rises. The lubricating oil 21 then enters the space within the cover 35 and is supplied to each oil supply portion through the oil supply hole 36.

Furthermore, during the time period when the internal pressure of the crankcase 1 is higher than the average pressure (X in Fig. 2), as described earlier, the oil return valve 3
2 opens, and the lubricating oil 21 returns to the bottom of the crankcase bottom cover 31.

In this way, the lubricating oil 21 is supplied to each part by utilizing the pressure fluctuation accompanying the reciprocating movement of the power piston 15, and the llI21
perform a slip.

In such an embodiment, there is no need to use an expensive oil supply pump as in the prior art, and the oil supply mechanism can be realized at low cost. In addition, a sufficient amount of oil can be obtained compared to the conventional oil-scraping plate that performs WA lubrication.

In the above embodiment, the setting position of the oil supply valve 33 was set near the crankcase partition Fi30, but as shown in FIG. 5, the same oil supply effect can be achieved even if it is provided at the lower part of the oil supply pipe 34.

Further, in the above embodiment, the oil return valve and the oil supply valve are basically of a flat plate type valve structure, but other valve structures may be used and the same effects as in the above embodiment can be obtained. FIG. 6 shows another valve structure. In the figure, 41 is a spring support pipe of the oil supply pipe, and 3Q'a is a crankcase partition plate 30.
' , 39 is a ball, and 40 is a spring. The ball 39 is brought into close contact with the oil return hole 30a of the crankcase partition plate 30' due to the load of the spring 40.

Such a valve structure also performs the same function as a flat plate valve. That is, when the j pressure inside the crankcase 1 increases,
The force due to the pressure becomes greater than the force of the spring 40, the spring 40 contracts, and the ball 39 moves downward. The oil return hole 30"a of the crankcase partition plate is then opened, and the lubricating oil falls to the bottom of the crankcase bottom cover 31. Note that this valve structure can also be easily applied to the oil supply valve side. .

Furthermore, so-called check valves other than the valve structures described in each of the above embodiments also have the same effects as those of the above embodiments.

〔Effect of the invention〕

As described above, according to the present invention, when refueling a Stirling engine, a valve structure that utilizes pressure fluctuations within the crankcase is provided at a fixed location within the crankcase, and each part is supplied with oil using the valve structure. Therefore, compared to conventional oil supply pumps and oil scrapers that supply oil, it is possible to provide stable oil supply at a lower cost.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the oil supply mechanism of a Stirling engine according to an embodiment of the present invention, FIG. 2 is a diagram showing pressure fluctuations in the crankcase, and FIGS. 3 and 4 are the oil supply mechanism of the above embodiment. 5 and 6 are diagrams showing valve structures according to other embodiments of the present invention, respectively.
FIG. 7 is a sectional view showing a conventional oil supply mechanism for a Stirling engine, and FIG. 8 is a sectional view showing another conventional oil supply mechanism. DESCRIPTION OF SYMBOLS 1... Crank case, 30... Crank case partition plate, 31... Crank case bottom cover, 32... Oil return valve, 33... Oil supply valve, 34... Oil supply pipe, 3
5... Cover, 37... Oil return hole, 38... Oil supply hole. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (3)

[Claims] (1) In a Stirling engine that generates pressure fluctuations in the cylinder due to the reciprocating motion of the displacer piston, which acts on the power piston to generate power, the
a crankcase partition plate that partitions the storage portion from the space above the storage portion; a first valve structure that opens and closes depending on the pressure difference between the upper and lower sides of the crankcase partition plate and causes lubricating oil to flow toward the lubricant storage portion; and the opposite direction thereof. An oil supply mechanism for a Stirling engine, comprising: a second valve structure that allows lubricant oil to flow out from the second valve structure; and an oil supply passage that supplies lubricant oil from the second valve structure to each movement mechanism section. (2) The oil supply mechanism for a Stirling engine according to claim 1, wherein the first and second valve structures are flat valve structures. (3) The oil supply mechanism for a Stirling engine according to claim 1, wherein the first and second valve structures are check valve structures.