JPH0645093Y2 - Gas seal device for Stirling engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a gas seal device for a Stirling engine.

(Prior Art) As shown in FIG. 7, a Stirling engine has an expansion chamber 3 in a cylinder 1 by an operating piston 2 in the cylinder 1.
And the compression chamber 4 are separated from each other, and a heater (not shown) for the both chambers 3 and 4,
It has a structure in which it is connected through a heat storage device and a cooler, and a working gas such as helium gas is sealed in the working space. In the Stirling engine having such a structure, in order to minimize the leakage of the working gas from one of the two chambers 3 and 4 to the other chamber, a plurality of longitudinally-spaced working pistons are provided on the outer peripheral surface of the working piston 2. The gas seal device 6 is attached to the ring groove 5 of.

As shown in FIGS. 8 and 9, the gas seal device 6 mounted in the ring groove 5 of the working piston 2 of the Stirling engine is generally a thermoplastic resin such as tetrafluoroethylene or a thermosetting resin such as polyimide. Ring 7 made of a composite material that is made of a conductive resin as a main material and is filled with another material for the purpose of improving wear resistance, heat resistance or strength, and the inner peripheral surface of the ring 7. , Cylinder inner peripheral surface 8 of ring 7
And the expander ring 9 made of steel for ensuring the contact pressure to the. The stepped ring 7 has the facing end faces 10, 11
A protrusion 10a extending in the circumferential direction from the upper surface of one of the ones 10 is provided, a protrusion 11a extending in the circumferential direction from the lower surface of the other end 11 of the mating end face is provided, and both protrusions 10a, 11a are superposed. And As a result, gaps A and B are secured between the end surface 10 and the protruding portion 11a and between the end surface 11 and the protruding portion 10a during mounting.

The high-pressure gas from the expansion chamber 3 or the compression chamber 4 is transferred to the step ring 7
The ring 7 is pressed against the wall surface 12 of the ring groove 5, and the working gas entering the bottom of the ring groove 5 cannot be diverted to the gap B by the expander ring 9, so that the sealing effect is high.

(Problems to be solved by the present invention) In a Stirling engine, a lubrication oil is mixed in a working gas, and the oil adheres to a cooler, a heat storage device, etc., and a non-lubricated seal is provided to prevent a decrease in heat exchange efficiency. Use a ring. In many cases, a seal ring 7 made of tetrafluoroethylene is used, but such a seal ring 7 made of resin is used.
Wears more than metal seal rings. For this reason, the thickness of the seal ring 7 becomes thinner with use, so that the gaps A and B become larger than in the initial stage of use. In addition, for example, since the working gas in the expansion chamber 3 has a high temperature as well as a high pressure, the high temperature and high pressure working gas acts on the seal ring 7. When the high temperature of the working gas acts on the seal ring 7, it causes the seal ring 7 itself to be easily softened. However, despite such a state, high pressure acts on the protruding portions 10a and 11a of the seal ring 7,
As shown in FIG. 10, the protruding portion 10a or 1 of the seal ring 7
1a is deformed, and sometimes the protrusion 10a or 11a is damaged. As a result, the sealing efficiency is lowered and the engine is not operated.

Further, the high-pressure working gas flows into the land between the seal rings 7, but if this inflow gas does not return, the working gas only flows into the land, and the gas pressure in the land becomes extremely high. Since the maximum pressure of the working gas or a gas pressure close to the maximum pressure acts on the seal ring 7, the protrusion 10a or 11a of the seal ring is further deformed or damaged.

Therefore, it is an object of the present invention to solve the above-mentioned problems of the prior art.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention basically sets a surface on which high-pressure working gas acts as a flat first surface,
The expander ring is a seal ring made of a non-lubricating material, which is a portion including a second surface and an outer peripheral surface on the opposite side thereof, and which has a protruding portion and a concave portion for receiving the protruding portion on the facing end faces of the facing ports. A combination of the technical means is used.

Furthermore, the cross-sectional shape of the protruding portion may be any of a triangle, a rectangle, and an arc, and the cross-sectional shape of the expander ring is a rectangle,
It may be circular. When a plurality of seal rings are used, the top ring may be a right angled seal ring.

(Operation) Although the high-pressure gas acts on the first surface of the seal ring, the high pressure is always received by the wall surface of the ring groove via the second surface, and the high pressure gas is not received only by the protruding portion. There is no deformation or damage to the protruding part.

(Embodiment) An example of use of the seal ring device 6 is as shown in FIG. 7, but the seal ring 13 made of a non-lubricating material used in the seal ring device 6 is flat and directed toward the high pressure gas side. The first surface 14 and the second surface 15 on the opposite side, which contacts the wall surface 12 of the ring groove 5 when a high pressure is applied to the seal ring 13, and the inner and outer peripheral surfaces 16 and 17, and which face each other. From the end face, a part of the second surface 15 and the outer peripheral surface 16 are included in a protruding portion 18
And a concave portion 19 including the second surface 15 and the outer peripheral surface 16 and having a similar shape to the protruding portion 18 is provided on the facing end surfaces.
To receive at.

The telescopic fitting of the protrusion 18 and the recess 19 is the first
When a high pressure is applied to the surface 14 of the ring, this pressure is applied to the wall surface of the ring groove 5.
Since it is possible to receive with 12, there is no deformation or damage of the protruding portion as in the past. The sectional shape of the protrusion 18 is not limited to the triangular shape shown in FIGS. 1-4, and may be rectangular as shown in FIG. 5 or arc-shaped as shown in FIG.

Preferably, the seal ring 13 is made of tetrafluoroethylene resin, and the surface of the protrusion 18 in contact with the wall surface of the ring groove is the second surface.
More than half of 15.

The expander ring 9 is preferably made of steel,
By attaching a resin film layer to the surface of the seal ring 13, it is possible to minimize the wear of the inner peripheral surface of the seal ring 13 due to the expander ring 9. The cross-sectional shape of the expander ring 9 is
A vertically long rectangle as shown in FIGS. 2, 5, and 6 may also be used.
It may be circular as shown in the figure. When the cross section is circular, as shown in FIG. 4, a semicircular recess 20 on the inner peripheral surface of the seal ring 13 is formed.
The expander ring 9 may be attached to the.

In the example shown in FIG. 7, two gas seal devices 13 are used, but three or more gas seal devices 13 may be used, and the top ring therein may be a seal ring having a right-angled mating port. For example, four seal ring devices (6) can be used, and the ring closest to each of the expansion chamber and the compression chamber can be used as the right angled mouth.

The land pressure between the seal rings 13 increases and the second surface 15
When high pressure acts on the first surface 14 of the seal ring 13 against the wall surface of the ring groove, the gap 21 between the first surfaces 14 communicates with the land, so that the high pressure at the land can be immediately reduced.

(Effect) According to the present invention, even if the thickness of the ring becomes thin due to wear of the outer peripheral surface of the ring and the gap between the end faces of the ring becomes large,
Since the high pressure is always received by the ring groove wall surface without being received only by the protruding portion, the protruding portion is not deformed or damaged. further,
When the land pressure increases, the first surface of the ring contacts the ring groove wall surface, and the land pressure is released through the gap, so the land pressure does not increase.

[Brief description of drawings]

FIG. 1 is a partial perspective view of a seal ring used in an example of the present invention, FIG. 2 is a sectional view thereof, and FIGS. 3-6 are sectional views showing respective embodiments in which a sectional shape of a protrusion or an expander ring is changed. FIG. 7 is a sectional view showing a working piston of a Stirling engine, FIG. 8 is a partial perspective view of a conventional seal ring,
FIG. 9 is a sectional view thereof, and FIG. 10 is a front view showing deformation of the ring. In the figure: 1 ... Cylinder, 2 ... Working piston, 3 ... Expansion chamber, 4 ... Compression chamber, 5 ... Ring groove, 6 ... Gas seal device, 9 ... Expander ring, 13 ... Seal Ring, 14 ... first surface, 15 ... second surface, 18 ... protrusion,
19 ... recess.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsunesaku Itaba 1-37 Hokuto-cho, Kashiwazaki-shi, Niigata Riken Kashiwazaki Plant (72) Inventor Momose Toyo 2-chome, Asahi-cho, Kariya city, Aichi prefecture Aisin Seiki Co., Ltd. (72) Inventor Satoshi Mizuno 2-1, Asahi-cho, Kariya city, Aichi Aisin Seiki Co., Ltd. (56) Reference JP-A-60-65959 (JP, A) JP-A-62 -184275 (JP, A) Actually open 58-106540 (JP, U) Actually open 2-469 (JP, U)

Claims (2)

[Scope of utility model registration request] 1. A gas sealing device for a Stirling engine, which is mounted in a ring groove provided on an outer peripheral surface of an operating piston that divides a cylinder into an expansion chamber and / or a compression chamber, wherein the gas sealing device is made of a non-lubricated material. And a expander ring arranged on the inner peripheral surface side of the seal ring, wherein the seal ring faces the ring first surface that is flat in the thickness direction and is in contact with the high-pressure side working gas. A projecting portion extending in the circumferential direction including a part of the second surface contacting one outer peripheral surface of the mouth end surface and the ring groove lower side wall surface, and the other outer peripheral surface of the facing mating end surface. A second surface of the protrusion when the high pressure working gas acts on the first surface of the seal ring, and a recess for receiving the projection including a part of the second surface of the ring. And the phosphorus adjacent to the protrusion The ring including the second surface and almost the entire area of the second surface are in contact with the wall surface of the ring groove, and the cross-sectional shape of the protrusion is triangular, arcuate or rectangular, and the cross-sectional shape of the expander ring is circular. A gas seal device for a Stirling engine, characterized in that 2. A gas seal device for a Stirling engine, which is mounted in a plurality of ring grooves provided on an outer peripheral surface of an operating piston which divides a cylinder into an expansion chamber and / or a compression chamber, wherein the gas seal device is non-lubricated. A seal ring made of a material, and an expander ring arranged on the inner peripheral surface side of the seal ring, and the shape of the seal ring to be mounted in the groove on the high pressure side of the seal ring is a right angled mouth. The other seal ring has an abutment shape in which the ring first surface that is flat in the thickness direction and that contacts the high-pressure side working gas, and the second outer surface of one of the facing abutment end surfaces and the ring groove lower side wall surface that are in contact with each other A protrusion extending in the circumferential direction in a form including a part of the surface of the ring, and the protrusion in a form including a part of the other outer peripheral surface of the facing mating end surface and the ring second surface. Has a recess for receiving, Said ring second containing the ring second surface pressure working gas to a first face of the serial seal ring adjacent to the second surface and the projecting portion of the projecting portion when acted
For substantially the entire surface of the ring groove wall surface, the cross-sectional shape of the protrusion is triangular, arc-shaped or rectangular, and further, the cross-sectional shape of the expander ring is circular, for a Stirling engine Gas seal device.