JPH04292560A - Rod seal device for stirling engine - Google Patents

Abstract

PURPOSE:To make a stirling engine compact. CONSTITUTION:In a rod seal device 10 for stirling engine, a cylinder 29 is provided in an intermediate chamber 21 in parallel with a rod 15, and a seal means 30 for sliding on the inner peripheral surface of the cylinder 29 is fixed to the rod 15. Consequently, intrusion of the oil, which intrudes from an oil chamber 23 to the intermediate chamber 21 through a scraper seal 22, to a work space side is hindered by the seal means 30. Engine itself can be thereby made compact in comparison with a conventional one, in which length of an intermediate chamber is made longer than a stroke length of a rod to prevent intrusion of the oil to a work space.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rod seal device for a Stirling engine.

0002

2. Description of the Related Art Conventionally, there is a rod seal device for a Stirling engine disclosed in Japanese Utility Model Publication No. 1-18831. In this prior art, an operating piston that slides within an operating cylinder and a guide piston that slides within a guide cylinder are connected by a rod, and a first piston is connected around the rod in series from the operating piston to the guide piston. A sealing means, an intermediate chamber, a second sealing means, an oil chamber, and a third sealing means are provided.

[0003] The entry of lubricating oil into the working space (compression space to expansion space) of a Stirling engine causes various problems, so the working piston slides in the working cylinder without any lubrication. The guide piston slides inside the guide cylinder while being lubricated with oil.

[0004] Also, generally, the first sealing means is a gas seal, the second sealing means is an oil scraper seal, and the third sealing means is an oil seal.

Further, the intermediate chamber communicates with a compression space, which is a space below the working cylinder, through an oil filter, and with an oil chamber through a high-pressure oil tank.

By adopting the above structure, in the Stirling engine of the prior art, lubricating oil for the guide piston is prevented from penetrating into the working piston side.

[0007]

[Problems to be Solved by the Invention] However, in the above-mentioned prior art, the passage of oil in the oil film cannot be avoided due to the function of the second sealing means, and as the oil film deteriorates, the oil in the oil chamber passes through the second sealing means. It passes through and enters onto the rod in the intermediate chamber. There is a fear that the oil that has entered the intermediate chamber becomes a mist due to the action of the working gas and the like, and may enter the working space from the first sealing means. However, this oil infiltration into the working space adheres to a heat exchanger (not shown) disposed in the working space, and causes carbonization due to the high temperature working gas, which adversely affects the flow of the working gas.

Therefore, the technical objective of the present invention is to prevent oil from entering the working space.

[0009]

[Structure of the invention]

0010

[Means for Solving the Problems] The technical means of the present invention taken to solve the above-mentioned technical problems of the present invention are as follows. A guide piston that is connected and slides within the guide cylinder, and a first sealing means, an intermediate chamber, a second sealing means, an oil chamber, and a third sealing means arranged in series around the rod from the working piston to the guide piston. In a rod sealing device for a Stirling engine having a sealing means, a cylinder is disposed in an intermediate chamber parallel to the rod, and a fourth sealing means that slides on the inner surface of the cylinder is fixed to the rod.

[0011]

[Operation] According to the above-mentioned technical means of the present invention, the lubricating oil that has passed through the second sealing means and entered the intermediate chamber is
Due to the action of the fourth sealing means disposed on the rod and the cylinder, no intrusion into the working piston side occurs.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples embodying the technical means of the present invention will be described below with reference to the accompanying drawings.

In the rod seal device 10 for a Stirling engine according to the embodiment of the present invention shown in FIG.
A rod 15 connects an actuating piston 12 that slides therein and a guide piston 14 that slides inside a crank chamber 25 of a guide cylinder 13. The inside of the working cylinder 11 is divided into an expansion space 16 and a compression space 1 by the working piston 12.
Since the Stirling engine according to the embodiment of the present invention is of a multi-cylinder type, the expansion space 16 is connected to the compression space of another working cylinder (not shown), and the compression space 17 is
It is also connected to the expansion space of another working cylinder (not shown). In addition, a heat sink 1 is installed on the connection line between the compression space and the expansion space.
8 and a regenerator 19 are provided. Furthermore, a working gas such as helium gas is sealed in the working spaces of the compression space to the expansion space, and is reciprocated between the spaces by the action of the working piston 12.

Around the rod 15, a gas seal (first seal means) 20, an intermediate chamber 21, an oil scraper seal (second seal means) 22, and an oil chamber 23 are arranged in series from the operating piston 12 toward the guide piston 14. , an oil seal (third seal means) 24 are provided. In this embodiment, the oil scraper seal 22 is of a two-stage series type.

Further, the intermediate chamber 21 communicates with the compression space 17 via an oil filter 26 and a one-way valve 28, and also communicates with the oil chamber 23 via a first high-pressure oil tank 27.

Furthermore, a cylinder 29 is disposed in the intermediate chamber 21 in parallel with the rod 15, and an oil stopper (fourth sealing means) 30 that slides on the inner surface of the cylinder 29 is attached to the rod 1.
It is fixed at 5. Note that the cylinder 29 has a communication hole 31.
is formed so that no pressure difference occurs between the chamber 32 and the intermediate chamber 21.

Furthermore, the intermediate chamber 21 communicates with a second high-pressure oil tank 34 via a conduit 33. The liquid level of the second high pressure oil tank 34 is determined by the float 35 and the control valve 3.
6, it is limited to a certain value or less. Although not shown, this liquid level limiting mechanism is also employed in the first high-pressure oil tank 27.

The operation of the Stirling engine rod seal device 10 having the above configuration will be explained below.

If lubricating oil or the like gets mixed into the working space (expansion space 16 to compression space 17) of the Stirling engine, it will cause various problems.
The operating piston 12 slides within the guide cylinder 13 without lubrication, and the guide piston 1 slides within the guide cylinder 13 with oil lubrication.
4 is sliding.

Furthermore, by the action of the gas seal 20 and the one-way valve 28, the intermediate chamber 21 and the first high pressure oil tank 27 are
is maintained at a pressure approximately close to the lowest pressure of the fluctuating pressure in the working space.

Further, the pressure difference between the intermediate chamber 21 and the oil chamber 23 connected via the first high-pressure oil tank 27 is kept small, and leakage of working gas from the intermediate chamber 21 to the crank chamber 25 is prevented by a scraper. This is prevented by a seal 22. At the same time, the scraper seal 22 also prevents the oil in the oil chamber 23 from entering the intermediate chamber 21, but its sealing performance is not perfect, and the oil equivalent to the thickness of the oil film adheres to the surface of the rod 15 and is removed from the intermediate chamber. It will infiltrate into 21.

[0022] Here, the oil adhering to the rod 15 and the oil in the form of mist in the intermediate chamber are prevented from penetrating into the gas seal 20 side from the oil stopper 30 due to the action of the cylinder 29 and the oil stopper 30. It is scraped up and falls to the lower surface of the intermediate chamber 21 in the drawing. Thereafter, these oils flow out to the second high-pressure oil tank 34 via the conduit 33, and flow out into the crank chamber 25 along with the control valve 36.

[0023]

As described above, in the present invention, the lubricating oil that has passed through the second sealing means and entering the intermediate chamber is activated by the action of the fourth sealing means disposed on the rod and the cylinder. It will not get into the piston side. Therefore, lubricating oil does not enter the working cylinder and does not adversely affect the output performance of the Stirling engine.

[Brief explanation of drawings]

FIG. 1 shows a configuration diagram of a rod seal device 10 of a Stirling engine 11 according to an embodiment of the present invention.

[Explanation of symbols]

10 Stirling engine rod seal device, 1
1 Working cylinder, 12 Working piston, 13
Guide cylinder, 14 Guide piston, 15 Rod, 20 Gas seal (first sealing means), 21
Intermediate chamber, 22 Oil scraper seal (second seal means), 23 Oil chamber, 24 Oil seal (
3rd sealing means), 29 cylinder, 30 oil stopper (4th sealing means).

Claims (1)

[Claims] Claims: 1. A working piston that slides within a working cylinder; a guide piston that is connected to the working piston via a rod and slides within a guide cylinder; In a rod sealing device for a Stirling engine, the rod sealing device has a first sealing means, an intermediate chamber, a second sealing means, an oil chamber, and a third sealing means arranged in series toward the rod, and a cylinder is provided in the intermediate chamber in parallel with the rod. In addition to arranging
A rod sealing device for a Stirling engine, characterized in that a fourth sealing means that slides on the inner surface of the cylinder is fixed to the rod.