JPS6323375B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rod seal mechanism for a Stirling engine, and more particularly to a rod seal mechanism for a Stirling engine in which an oil scraper containing a magnetic fluid is disposed between a gas chamber and a liquid chamber.

In a Stirling engine, working gas is reciprocated between an expansion chamber, which is a high-temperature part, and a compression chamber, which is a low-temperature part, in the cylinder, which is divided by a working piston, and the working gas causes the working piston to reciprocate and connect to the working piston. The output is taken out to the outside through a rod, which is connected to a guide piston that cooperates with the output extraction mechanism. The guide piston is located on the crank chamber side, which is at atmospheric pressure, and the connecting part between the rod and the operating piston is located on the compression side, which is at high pressure.
A pressure difference occurs between the two connecting portions, making it easy for working gas to leak from the compression chamber to the crank chamber. On the other hand, since the output of a Stirling engine is proportional to the average pressure of the working gas, leakage of the working gas from the compression chamber to the crank chamber is important for the purpose of preventing a drop in output. Starting from the compression chamber side, the gas seal, gas chamber, oil scraper, liquid chamber, and pumping seal are arranged in order.
The applicant has already proposed a rod seal mechanism that communicates the liquid chamber and the upper part of the oil scraper through an oil tank.

This invention relates to the improvement of the rod seal mechanism proposed by the present applicant as described above, and in particular, a technology in which the oil scraper is composed of a magnetic fluid and a magnet, and the upper and lower parts of the magnetic fluid are made to have approximately equal pressure. The magnetic fluid prevents the oil from rising in the liquid chamber, and also releases the sliding heat of the rod to the outside through the magnetic fluid, thereby promoting the cooling effect of the rod and its sliding parts. present.

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

The inside of the cylinder 2 of the Stirling engine 1 is divided by an operating piston 3 into an expansion chamber 4 serving as a high temperature section and a compression chamber 5 serving as a low temperature section. The expansion chamber 4 is connected to the compression chamber of an adjacent cylinder (not shown) via a heater, a heat storage device, and a cooler, and working gas such as helium or hydrogen is reciprocated between the expansion chamber 4 and the compression chamber of the adjacent cylinder. During this period, isothermal compression, isovolume change, isothermal expansion, and isovolume change are repeated to move the operating piston 3 up and down.

This reciprocating movement of the working piston 3 is extracted as mechanical work to the outside via a rod 8 which is connected to the working piston 3 and to a guide piston 7 which cooperates with the crank mechanism 6.

Between the cylinder 2 and the crankcase 9, in order to seal the rod 8, from the compression chamber 5 side, there is a gas seal 10, a gas chamber 11 maintained at the lowest pressure of the working gas, an oil scraper 12, and a lubricant. A liquid chamber 13 and a pumping seal 14 are provided, which are always filled with oil, water, etc. The intermediate chamber 11 communicates with the compression chamber 5 via a fixed orifice 15 , a filter case 17 having an oil filter 16 , and a check valve 18 .
1 is maintained at the lowest pressure of the working gas, and oil in the working gas flowing from the intermediate chamber 11 to the compression chamber 5 is filtered by a filter 16. Fixed orifice 1 between filter case 17 and intermediate chamber 11
5 acts as a buffer when the operating space pressure fluctuates during output control, etc., and prevents liquids such as oil and water in the oil tank 19 from flowing back. Further, the oil tank 19 described above is arranged between the liquid chamber 13 and the upper part of the oil scraper 12. The oil tank 19 always fills the liquid chamber 13 with oil and returns the oil separated by the filter 16 and the oil leaked from the oil scraper 12 to the oil tank 19 through a pipe 20 connected just above the oil scraper 12. . Furthermore, the liquid chamber 1 is raked up by the pumping seal 14.
3, the excess oil relative to the volume of the liquid chamber 13 is returned to the oil tank 19, and the excess oil in the oil tank 19 is returned to the crankcase 9. The liquid chamber 13 prevents the working gas that has leaked into the intermediate chamber 11 from leaking into the crankcase 9, and the intermediate chamber 11 prevents the working gas that has leaked into this chamber via the gas seal 10 into the compression chamber that becomes the working space. 5
Since the amount of working gas is refluxed, a constant amount of working gas can be maintained in the closed circuit connecting the expansion chamber and the compression chamber, and there is no reduction in output due to leakage of the working gas. The liquid chamber 13 contains oil and working gas, and the pressure of the working gas in the liquid chamber 13 is approximately equal to the pressure of the working gas in the intermediate chamber 11, so that no differential pressure is created between the upper and lower portions of the oil scraper 12.

Oil scraper 12 used in this invention
is composed of a magnetic fluid 21 and a magnet 22.
A slight gap is created between the land between the chamber 23 in which the magnet 22 is arranged and the intermediate chamber 11 and the rod 8, and the magnetic fluid 21 is concentrated in this gap by the magnetic force of the magnet 22. Also, a chamber 23 in which the magnet 22 is arranged and a liquid chamber 1
A slight gap is created between the land and the rod 3, and the magnetic fluid 21 is concentrated in this gap by the magnetic force of the magnet 22. Protrusions are made on the surface of the land facing the rod 8 to increase the magnetic flux density, and the magnetic fluid 2
It is better to increase the sealing effect by crowding 1.

[Brief explanation of the drawing]

The figure is a sectional view showing an example of the present invention. In the diagram: 1... Stirling engine, 2... cylinder,
3... Working piston, 8... Rod, 9... Crank case, 11... Intermediate chamber, 12... Oil scraper,
13...liquid chamber, 19...oil tank, 21...magnetic fluid, 22...magnet.

Claims (1)

[Claims] 1 A gas seal, a gas chamber, an oil scraper, a liquid chamber, and a pumping seal are arranged in order from the working space side around a rod extending from inside the cylinder between the working space in the cylinder and the crank chamber. , a rod seal mechanism for a Stirling engine in which the liquid chamber is communicated with the upper part of the oil scraper through an oil tank, the upper and lower parts of the oil scraper are made to have substantially equal pressure, and the oil tank is communicated with the crank chamber. ,
A rod seal mechanism for a Stirling engine, wherein the oil scraper comprises a magnet and a magnetic fluid, and the magnetic fluid fills a gap between the gas chamber and the liquid chamber by the magnetic force of the magnet to perform a sealing action.