CN110552811B - 'square' -shaped mutually-buckled type Stirling engine piston assembly and Stirling engine - Google Patents

Abstract

The invention provides an interlocking type Stirling engine piston assembly and a Stirling engine. The piston ring and the piston top are sequentially arranged on the piston bottom, and the piston bottom is connected with the piston rod. The piston ring main body is an open ring, the opening is of an interlocking structure, a through hole shaped like a Chinese character 'kou' is formed in the middle of the interlocking structure, and the piston ring auxiliary body is embedded into the opening of the piston ring main body. In the whole piston assembly, the outer diameter of the piston ring main body is the largest, and the outer diameters of the piston top and the piston bottom are equal. The interlocking structure of the invention sets the upper limit and the lower limit of the deformation of the piston ring, thereby not only ensuring that the piston ring adjusts the self-tension degree along with the change of the pressure in the cylinder, but also preventing the piston ring from deforming excessively and increasing friction, and simultaneously effectively preventing gas from leaking, ensuring that the cylinder has good sealing property and improving the performance of the Stirling engine.

Description

A "mouth"-shaped interlocking Stirling engine piston assembly and Stirling engine

technical field

The invention relates to the field of engine pistons, in particular to a "mouth"-shaped interlocking Stirling engine piston assembly and a Stirling engine.

Background technique

As an external combustion engine, Stirling engine has the advantages of simple structure, low vibration and noise, and high efficiency. It can utilize a variety of heat sources, such as solar energy, biomass energy, fossil fuels, industrial waste heat, electric energy, etc., and belongs to an environment-friendly heat engine. . The piston ring of the Stirling engine works under high temperature, high pressure and high load conditions, and the friction method between the piston ring and the cylinder wall is dry friction, and the friction and wear are serious, which seriously affects the service life of the piston ring. In addition, the tightness of the piston rings is also critical, both of which can directly affect the performance of the Stirling engine.

The inventions based on the piston of the Stirling engine mainly include: Patent application CN 108661820 A discloses a split-type Stirling engine piston assembly, which is composed of a piston ring main body and a piston ring auxiliary body, and the gap between the two is at the axis of the shaft. It affects the sealing performance of the piston assembly upward, and the gap becomes larger when the piston ring expands, and the effect is more significant. And when the piston ring is worn, the deformation of the piston ring is too large when it expands, which is easy to cause the cylinder to be pulled, which affects the normal operation of the Stirling engine.

SUMMARY OF THE INVENTION

Aiming at the deficiencies of the existing piston in terms of deformation, sealing and friction, the present invention provides a novel piston assembly and a Stirling engine, which can greatly improve the performance of the piston in these aspects. The invention sets an upper limit and a lower limit for the deformation of the piston ring, which can not only ensure that the piston ring adjusts its own tension with the change of the pressure in the cylinder, but also prevent the piston ring from increasing friction due to excessive deformation, and also provides the cylinder with Good sealing can well prevent gas leakage in the radial and axial directions of the cylinder.

The present invention achieves the above technical purpose through the following technical means.

A "mouth"-shaped interlocking type Stirling engine piston assembly, the piston assembly includes a piston top, a piston ring and a piston bottom, wherein the piston ring further includes a main body and a secondary body, and the secondary body is placed at the opening of the piston ring main body Inside. The main body of the piston ring and the top of the piston are sequentially installed on the bottom of the piston, the bottom of the piston is directly connected with the piston rod, and the whole of the piston assembly reciprocates in the cylinder. The main body of the piston ring is a split ring, the opening of the main body of the piston ring is an interlocking structure, and a "mouth"-shaped through hole is formed in the middle of the interlocking structure; the auxiliary body of the piston ring is embedded in the opening of the main body of the piston ring, and the auxiliary body of the piston ring can be Sliding circumferentially along the body of the piston ring.

Further, the outer diameter of the piston ring body is larger than the outer diameters of the piston top and the piston bottom.

Further, the piston ring auxiliary body has a base body in an arc shape, and the outer side of the arc has a convex "convex" structure. The interlocking structure of the ring main body is in the "mouth"-shaped through hole; the radian of the circular arc-shaped base part of the piston ring auxiliary body is 22° to 26°, and the radian of the base part of the piston ring auxiliary body is 20° larger than that of the convex part. ; The inner diameter of the piston ring body is the same as the inner diameter of the main body of the piston ring.

Further, the axial thickness of the protruding portion of the auxiliary body of the piston ring is smaller than the axial thickness of the base portion.

Further, at the opening of the main body of the piston ring, in the radial direction, the difference between the radian of the base part and the convex part is at least 10°; there are two slits between the gap on the outside of the main body of the piston ring and the interlocking structure, and the radian of the slit It can be changed between 0° and 2°; the radian of the "mouth"-shaped through hole at the opening of the main body of the piston ring is changed between 6° and 8°.

Further, the main body of the piston ring is evenly distributed with convex arcs in the inner direction of the ring.

Further, there are no less than two convex arcs.

Further, the opening of the piston ring body is located between the two convex arcs.

A Stirling engine comprising the above-mentioned "mouth"-shaped interlocking Stirling engine piston assembly.

The beneficial effects of the present invention are:

1. In the "mouth"-shaped interlocking Stirling engine piston-piston assembly of the present invention, the slit existing on the piston ring main body is partially shielded by the base body of the piston ring auxiliary body in the radial direction, and is axially blocked by the piston ring auxiliary body. The interlocking structure of the main body of the piston ring itself is shielded, which avoids the occurrence of air leakage channels and realizes good sealing in the radial and axial directions of the cylinder.

2. The "mouth"-shaped interlocking Stirling engine piston assembly of the present invention sets a deformation upper limit for the piston ring by inserting the "convex" piston ring body into the interlocking piston ring main body, avoiding the Excessive deformation of the piston ring causes failures such as pulling the cylinder, thereby reducing the friction between the piston and the cylinder.

3. The "mouth"-shaped interlocking Stirling engine piston assembly of the present invention, through the cooperation of the main body of the piston ring and the auxiliary body of the piston ring, can realize the adjustment of the tension of the piston ring with the cylinder pressure, which is beneficial to Anti-friction and sealing.

Description of drawings

Fig. 1 is a three-dimensional view of the piston assembly of the "mouth"-shaped interlocking Stirling engine according to the present invention.

FIG. 2 is an assembly diagram of the main body of the piston ring and the auxiliary body of the piston ring according to the present invention.

FIG. 3 is a structural diagram of the interlocking structure at the opening of the main body of the piston ring according to the present invention.

FIG. 4 is a three-dimensional structural diagram of the piston ring auxiliary body according to the present invention.

Fig. 5 is the installation diagram of the piston assembly of the "mouth"-shaped interlocking Stirling engine according to the present invention.

In the picture:

1-piston ring main body; 2-piston ring auxiliary body; 3-piston top; 4-piston bottom; 5-fastening screw; 6-convex arc; 7-piston cylinder.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

As shown in Figures 1 and 5, the "mouth" type interlocking Stirling engine piston assembly of the present invention is mounted on the piston rod, and the piston assembly reciprocates in the piston cylinder 7, and the piston The assembly includes a piston ring main body 1, a piston ring sub-body 2, a piston top 3 and a piston bottom 4; the piston bottom 4 is fixedly connected to the piston rod; the piston ring main body 1 and the piston top 3 are sequentially installed on the piston through tightening screws 5. bottom 4.

As shown in FIG. 2 and FIG. 3 , the piston ring body 1 is a split ring, the opening of the piston ring body 1 is an interlocking structure, and a “mouth”-shaped through hole is formed in the middle of the interlocking structure. The piston ring auxiliary body 2 is placed at the opening of the piston ring main body 1, and the piston ring auxiliary body 2 can slide along the circumferential direction of the piston ring main body 1; as shown in FIG. 4, the piston ring auxiliary body 2 is The base body is in the shape of a circular arc, and the outer surface of the circular arc has a convex "convex" structure, and the axial thickness of the convex part is smaller than the axial thickness of the base body. The stepped surface at the opening of the main body 1 is fitted, and the "convex" piston ring sub-body 2 can slide along the stepped surface at the opening of the piston ring main body 1; the outer diameter of the piston ring main body 1 is larger than that of the piston top 3. The outer diameter of the piston ring body 1 is larger than the outer diameter of the piston bottom 4 .

As shown in FIG. 2 , the piston ring main body 1 is provided with three convex arcs 6 evenly distributed in the inner direction of the ring. The opening of the piston ring main body 1 is located between the two convex arcs 6 . While ensuring the strength of the piston ring main body 1 , the wall thickness of the piston ring main body 1 is controlled to an appropriate value.

As shown in Figs. 1 and 2, the piston ring sub-body 2 is embedded in the opening of the piston ring main body 1, and the two restrict each other. When the piston ring main body 1 contracts, the interlocking structure of the piston ring main body 1 and the base portion of the piston ring auxiliary body 2 will constrain it within a limited range. When the piston ring main body 1 expands to a certain extent, the interlocking structure at the opening of the piston ring main body 1 realizes the interlocking through the convex part of the piston ring auxiliary body 2, so as to limit the piston ring main body. 1 The effect of excessive deformation.

As shown in Figures 1 and 5, the cylinder pressure acts on the inner surface of the piston ring auxiliary body 2, so that the piston ring auxiliary body 2 closely fits on the piston ring main body 1, and seals the working fluid in the cylinder. At the same time, a certain tension is provided for the piston ring body 1 . Cylinder pressure acts on the inner surface of the piston ring body 1, providing a force to tension the piston ring body 1, and the piston ring body 1 is deformed. When the cylinder pressure becomes larger, the outer diameter of the piston ring body 1 becomes larger, the pressure acting on the cylinder wall of the piston cylinder 7 becomes larger, and the friction loss between the piston ring body 1 and the cylinder wall of the piston cylinder 7 becomes larger . When the cylinder pressure is too high or the piston ring main body 1 is worn too much, the piston ring main body 1 tends to be overstretched. At this time, the interlocking structure at the opening of the piston ring main body 1 fastens the piston ring auxiliary body 2, The self-deformation is limited to be too large, and the effect of reducing the friction between the piston and the cylinder is achieved. When the cylinder pressure becomes smaller, the outer diameter of the piston ring body 1 becomes smaller, the pressure acting on the cylinder wall of the piston cylinder 7 becomes smaller, and the friction loss between the piston ring body 1 and the cylinder wall of the piston cylinder 7 becomes smaller.

As shown in Figures 1 and 2, the protruding part of the piston ring auxiliary body 2 is embedded in the "mouth"-shaped through hole of the interlocking structure of the piston ring main body 1, and the base part of the piston ring auxiliary body 2 is placed in the The piston ring main body 1 is radially inward. The slits and gaps existing on the piston ring main body 1 are shielded by the base portion of the piston ring auxiliary body 2 in the radial direction; in the axial direction, they are shielded by the interlocking structure on the piston ring main body 1 . In both radial and axial directions, the occurrence of leakage passages is avoided, a good sealing of the working fluid in the cylinder is achieved, and the performance of the Stirling engine is improved.

The described embodiment is the preferred embodiment of the present invention, but the present invention is not limited to the above-mentioned embodiment, without departing from the essence of the present invention, any obvious improvement, replacement or All modifications belong to the protection scope of the present invention.

Claims (7)

1. A "mouth" type interlocking Stirling engine piston assembly is characterized in that, comprising piston ring main body (1), piston ring auxiliary body (2), piston top (3) and piston bottom (4) The piston ring main body (1) and the piston top (3) are sequentially installed on the piston bottom (4) from bottom to top by tightening screws (5), and the outer diameter of the piston ring main body (1) is larger than the piston top (3) and the outer diameter of the piston bottom (4); the piston ring main body (1) is a split ring, the opening of the piston ring main body (1) is an interlocking structure, and the middle of the interlocking structure forms a "mouth" shape Through holes, there are two slits between the outer notch of the piston ring main body (1) and the interlocking structure, and the radian of the slits can be changed between 0° and 2°; the opening of the piston ring main body (1) has a "mouth" shape The radian of the through hole varies between 6° and 8°; the piston ring auxiliary body (2) is a base body in a circular arc shape, and the outer side of the circular arc has a convex "convex" structure, and the axial thickness of the convex part is less than The axial thickness of the base part, the protruding part of the piston ring auxiliary body (2) is embedded in the "mouth"-shaped through hole of the interlocking structure of the piston ring main body (1), the piston ring auxiliary body (2) can be along the piston ring main body (1) Circumferential sliding, the inner diameter of the piston ring auxiliary body (2) is the same as the inner diameter of the piston ring main body (1). 2. The "mouth"-shaped interlocking Stirling engine piston assembly according to claim 1, characterized in that, the radian of the convex portion of the piston ring auxiliary body (2) is 2° to 6°, so The radian of the circular arc-shaped base part of the piston ring auxiliary body is 22°-26°, and the radian of the base part of the piston ring auxiliary body (2) is 20° larger than that of the convex part. 3. The "mouth"-shaped interlocking Stirling engine piston assembly according to claim 2, characterized in that, at the opening of the piston ring main body (1), along the radial direction, the difference between the base part and the protruding part is The difference in radians is at least 10°. 4. The "mouth"-shaped interlocking Stirling engine piston assembly according to claim 1, characterized in that, the piston ring main body (1) is uniformly provided with convex arcs (6) in the inner direction of the ring . 5. The "mouth"-shaped interlocking Stirling engine piston assembly according to claim 4, characterized in that there are no less than two convex arcs (6). 6. The "mouth"-shaped interlocking Stirling engine piston assembly according to claim 4, wherein the opening of the piston ring body (1) is located between two convex arcs (6). . 7. A Stirling engine comprising the "mouth" interlocking Stirling engine piston assembly of any one of claims 1-6.

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