JPS6319583Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a rod seal mechanism for a Stirling engine. Specifically, this invention connects an oil tank that communicates with a liquid sealing chamber with a crank chamber, and returns a certain amount of oil from the oil tank to the crank chamber. Regarding the rod seal mechanism for Stirling engines.

In a Stirling engine, working gas is used to reciprocate between an expansion chamber, which is a high temperature part, and a compression chamber, which is a low temperature part, in a cylinder that is partitioned by a working piston. The output is output to the outside via a rod connected to the output mechanism, and this rod is connected to a guide piston that cooperates with the output output mechanism. The guide piston is located on the crank chamber side, which is at atmospheric pressure, and the connection between the rod and the working piston is located on the compression side, where the pressure is high, so a pressure difference is created between the two connections, and the working gas is It is becoming easier 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 working gas from the compression chamber to the crank chamber is important for the purpose of preventing a drop in output. Starting from the chamber side, a gas seal, an intermediate chamber communicating with the compression chamber, an oil scraper, a liquid sealing chamber, and an oil seal are arranged in order, and a seal rod that communicates the oil sealing chamber with the upper part of the oil scraper via an oil tank is installed in the main assembly. The applicant has already provided.

This invention relates to the improvement of the rod seal proposed by the applicant as described above, and furthermore, a pumping seal is disposed between the liquid sealing chamber and the crank chamber, and the oil tank and the crank chamber are made to communicate with each other. An object of the present invention is to provide a rod seal mechanism for a Stirling engine, which enhances the sealing effect by always sealing a predetermined amount of liquid into the rod.

An embodiment of this 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, an intermediate 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. Intermediate room 11
communicates with the compression chamber 5 through a filter case 17 having a fixed orifice 15 and an oil filter 16 and a check valve 18, and maintains the intermediate chamber 11 at the lowest pressure of the working gas by the check valve 18. The oil in the working gas flowing from the compressor to the compression chamber 5 is filtered by a filter 16. The fixed orifice 15 between the filter case 17 and the intermediate chamber 11 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. . moreover,
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 containment chamber 13 with liquid such as oil and water, and also collects the oil separated by the filter 16 and the oil leaked from the oil scraper 12 through a pipe 20 connected just above the oil scraper 12. oil tank 19
Return to. Furthermore, the oil that has been pumped up by the pumping seal 14 and entered the liquid sealing chamber 13 is
An excess amount relative to the volume of the liquid chamber 13 is returned to the oil tank 19.

The liquid sealing 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 compresses the working gas that has leaked into this chamber via the gas seal 10 to become a working space. Since the flow is returned to the chamber 5, 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 oil tank 19 and the inside of the crankcase 9 are connected by a circuit 22 having a solenoid valve 21. An oil level detector 23 is disposed in the oil tank 19, and a signal from the detector 23 is converted and sent to the solenoid valve 21 via an amplification circuit to control the opening and closing of the valve 21. The level detector 23 may be a known one using a metal float, a mercury switch, a change in capacitance, or the like. If the oil in the liquid chamber 13 exceeds a predetermined amount due to the scraping of the pumping seal 14, the oil returned to the oil tank 19 and returned from the oil scraper 12 enters the tank 19, and the oil level in the tank 19 increases. When the predetermined value is exceeded, the level detector 23 sends an instruction signal to the solenoid valve 21 to open it, causing the oil in the oil tank 19 to flow back into the crankcase 9, thereby lowering the oil level in the tank 19.
When the level reaches a predetermined level, the solenoid valve 21 closes, cutting off communication between the oil tank 19 and the crankcase 9. As a result, the oil in the liquid chamber 13 and the oil tank 19 is always kept at a predetermined amount, and the oil management in the chamber 13 and the tank 19 is extremely easy, and the rod sealing effect can be enhanced. Further, the cycle of oil passing from the crankcase 9 through the pumping seal 14, the sealing chamber 13, and the oil tank 19 also makes it possible to dissipate heat from the seal portion 14 and clean the oil.

[Brief explanation of drawings]

The figure is a front view showing the rod seal of the Stirling engine of this invention. In the diagram: 1... Stirling engine, 2... cylinder, 3... working piston, 4... expansion chamber, 5...
Compression chamber, 6... Crank mechanism, 8... Rod, 1
0... Gas seal, 11... Intermediate chamber, 12... Oil scraper, 13... Liquid sealing chamber, 14...
...Pumping seal, 15...Fixed orifice,
16... Oil filter, 17... Filter case, 18... Check valve, 19... Oil tank, 21... Solenoid valve, 23... Level detector.

Claims (1)

[Scope of utility model registration request] A gas seal, an intermediate chamber, an oil scraper, a liquid sealing 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. The intermediate chamber is communicated with the working space via a fixed orifice, an oil filter, and a check valve, and the liquid sealed chamber is communicated with the upper part of the oil scraper via an oil tank, and the oil tank is introduced into the crank chamber. A rod seal mechanism for a Stirling engine, characterized in that communication between the oil tank and the inside of the crank chamber is controlled by a solenoid valve that is opened and closed by a level detector in the oil tank.