A combined oil and gas seal for a delta rotor engine

Abstract

The application discloses a lubricating oil and gas composite sealing structure for a triangular rotor engine, three annular expansion ring grooves are formed in end faces of both ends of a rotor, and an air sealing expansion ring and two-stage oil sealing expansion rings are sequentially accommodated in the radial direction from a combustion chamber side to a rotor inner cavity side; a wave spring is arranged at the bottom of each expansion ring groove, and corresponding expansion rings are axially pressed and attached to the inner surface of a side cylinder cover; a compression rubber ring is arranged on the inner side of each two-stage oil sealing expansion ring to realize radial lubricating oil sealing; a radial matching gap is reserved between the air sealing expansion ring and the expansion ring groove to form a gas self-tightening effect, and the air sealing expansion ring is arranged between a side sealing sheet and the oil sealing expansion ring. The application realizes double lubricating oil blocking and staged gas sealing, effectively reduces lubricating oil consumption and carbon deposition, blocks the gas channeling path of the air inlet and exhaust end faces, and significantly improves the operation reliability and service life of the engine.

Description

Technical Field

[0001] This invention belongs to the field of sealing technology for triangular rotor engines, and in particular, relates to a composite sealing structure for lubricating oil and gas in a triangular rotor engine. Background Technology

[0002] The triangular rotor engine completes its four-stroke working cycle through planetary rotation of a triangular rotor within a double-arc subcycloidal cylinder. It has been applied in automobiles, aerospace, drones, ships, special vehicles, and portable power generation equipment. Especially in the context of the rapid development of the new energy vehicle industry, its miniaturization, high power density, and low vibration characteristics make it an ideal candidate for range extenders in range-extended electric vehicles. The rotor, as part of the engine's combustion chamber, is a high-temperature component. The engine has oil nozzles mounted on an eccentric shaft, which circulate lubricating oil to cool the rotor, resulting in high-pressure lubricating oil within the rotor cavity. If the lubricating oil seal between the rotor and the combustion chamber is poor, a large amount of lubricating oil will enter the rotor area near the combustion chamber or directly into the combustion chamber, leading to high oil consumption. During operation, if high-temperature combustion gases leak from the side, the leaked gas will impair the engine's lubrication and make the lubricating oil more prone to carbon buildup.

[0003] The sealing of triangular rotor engines, including the seal between the rotor and the side cylinder head, is prone to wear and leakage, making it one of the core challenges in developing triangular rotor engines. Compared to traditional four-stroke piston engines, the piston internal combustion engine's expansion ring seal is a surface seal with a large contact area and relatively uniform pressure distribution; while the triangular rotor engine uses a line seal, resulting in very high local pressure. Moreover, the combustion chamber typically has only one main top seal and side seal. Once this seal fails, the performance, lifespan, and reliability of the entire engine will be severely affected.

[0004] Patent application CN120251372A discloses a sealing and lubrication system for a rotary engine, comprising at least one cylinder body, a rotor mounted within the cylinder body, and end caps on both sides of the cylinder body. The rotor is characterized by having a radial sealing system, an end-face gas sealing system, an end-face oil sealing system, and a seal lubrication system. The radial sealing system, located in a radial seal mounting groove at the junction of the two rotor working surfaces, includes: radial sealing rollers, a radial sealing bearing cage, and drag-reducing rollers. The radial sealing rollers are rolling components. The bearing cage is an elastic support structure with drag-reducing rollers mounted on top, tangential to the radial sealing rollers. The elastic support force generated by the radial sealing bearing cage applies a thrust to the radial sealing rollers through the drag-reducing rollers, causing the radial sealing rollers to roll tightly against the inner wall of the cylinder and absorb its vibration energy, thus completing the sealing and isolation between the rotor and the cylinder in the radial airtight section between the working surfaces. Several radial oil guide holes are provided on the radial seal mounting groove, which are connected to the rotor lubricating oil common channel to provide lubrication and cooling for the moving parts of the radial sealing system [1-3]. The end face air seal of this patent is arranged in segments along the contour of the rotor's triangular working surface. There are sealing connection breakpoints at the three apex corners of the rotor, and the end face seal is only achieved by the end sealing top ball. The end seal is weak, and high-temperature and high-pressure gas is prone to leak from the breakpoint. Summary of the Invention

[0005] This invention primarily addresses the sealing issues in existing triangular rotor engines, including the seal between the rotor and the side cylinder head. These seals are prone to wear and leakage, making them one of the core challenges in developing triangular rotor engines. Compared to traditional four-stroke piston engines, the piston internal combustion engine's expansion ring seal is a surface seal with a large contact area and relatively uniform pressure distribution. In contrast, the triangular rotor engine uses a line seal, resulting in extremely high local pressure. Furthermore, the combustion chamber typically has only one main top seal and side seal. If this seal fails, the performance, lifespan, and reliability of the entire engine will be severely affected. This invention proposes a composite sealing structure for lubricating oil and gas in triangular rotor engines.

[0006] A composite sealing structure for lubricating oil and gas in a triangular rotor engine is disclosed. The sealing structure is disposed between the engine rotor and the side cylinder head. Multiple annular expansion grooves are respectively formed on the two ends of the triangular rotor. These expansion grooves are arranged radially from the combustion chamber side towards the lubricating oil side of the rotor's inner cavity. A first-stage oil-sealing expansion ring, a second-stage oil-sealing expansion ring, and a gas-sealing expansion ring are sequentially arranged along the expansion grooves. The first-stage and second-stage oil-sealing expansion rings are arranged radially towards the rotor's inner cavity, while the gas-sealing expansion rings are arranged radially towards the combustion chamber side. A sealing layer is provided between the first-stage oil-sealing expansion ring and the radial inner wall of the corresponding expansion groove. A rubber ring is provided between the second-stage sealing oil expansion ring and the radial inner wall of the corresponding expansion ring groove. The rubber ring is compressed radially to achieve a radial lubricating seal between the sealing oil expansion ring and the expansion ring groove. A wave spring is provided at the bottom of each expansion ring groove. The wave spring axially abuts against the lower end face of the corresponding expansion ring, so that one side end face of the corresponding expansion ring is pressed against the inner surface of the side cylinder head. A radial fitting gap is provided between the radial outer wall of the sealing expansion ring and the side wall of the corresponding expansion ring groove. The combustion gas in the combustion chamber can enter the bottom of the expansion ring groove through the radial fitting gap, forming an axial thrust to press the sealing expansion ring against the inner surface of the side cylinder head.

[0007] Furthermore, the first-stage oil sealing ring and the second-stage oil sealing ring, and the axial end faces of the first-stage oil sealing ring and the second-stage oil sealing ring that contact the side cylinder head are all provided with narrow lip edges. The axial width of the narrow lip edge is 0.5mm, and the surface of the narrow lip edge is plated with a chromium-plated wear-resistant layer.

[0008] Furthermore, the top of the narrow lip edge of both the first-stage sealing expansion ring and the second-stage sealing expansion ring is provided with an annular inclined surface with an inclination angle of 2°. The annular inclined surface is used to draw lubricating oil into the lip edge contact area to form a bearing oil film when the cylinder head on the opposite side of the rotor moves circumferentially.

[0009] Furthermore, the cross-sectional diameter ΦR of the rubber ring satisfies the relationship: ΦR>(L r -L m +L n ), wherein the L r L is the radial width of the expansion groove. m For the radial thickness of the sealing oil expansion ring, L n The diameter of the radial section of the rubber ring in its free state; the rubber ring is made of heat- and oil-resistant fluororubber, and in the compressed state, the sealing expansion ring is pressed tightly against the inner wall of the expansion ring groove.

[0010] Furthermore, a radial fitting clearance is provided between the outer end face of the sealing expansion ring and the outer side wall of the expansion ring groove. The radial fitting clearance is less than 0.2mm, which is used to prevent the sealing expansion ring from getting stuck in the expansion ring groove and to allow gas to enter the bottom of the expansion ring groove to assist in pressing and sealing.

[0011] Furthermore, the sealing expansion ring is an annular structure, and the axial end face of the sealing expansion ring that contacts the side cylinder head is provided with a narrow lip. The axial width of the narrow lip on the sealing expansion ring is 0.5mm. One end of the narrow lip on the sealing expansion ring is provided with a slope with an inclination angle of 2°, so that the sealing expansion ring is close to the inner wall of the expansion ring groove.

[0012] Furthermore, it also includes a side sealing sheet, wherein the air sealing expansion ring is arranged radially between the engine side sealing sheet and the second-stage oil sealing expansion ring; the air sealing expansion ring is used to block the air passage connecting the exhaust chamber and the intake chamber through the gap between the rotor and the side cylinder head.

[0013] Furthermore, the outer walls of both the first-stage and second-stage sealing expansion rings are flat and contact the outer wall of the expansion ring groove; both the first-stage and second-stage sealing expansion rings have a concave annular groove on their radial inner side to accommodate a rubber ring with a circular cross-section; after the rubber ring is assembled, one end of the rubber ring abuts against the inner wall of the annular groove, and the other end abuts against the inner wall of the expansion ring groove, thereby achieving radial sealing.

[0014] Furthermore, a side sealing plate is circumferentially embedded on the outermost radial side of the rotor end face, and the axial end face of the side sealing plate is attached to the inner surface of the side cylinder head. The sealing gas expansion ring is arranged radially between the engine side sealing plate and the second-stage sealing oil expansion ring, forming a two-stage gas sealing structure with the side sealing plate to seal step by step.

[0015] Furthermore, when the triangular rotor moves to the top dead center of the exhaust stroke, and both the intake and exhaust ports are blocked by the rotor end face, the distance between the outer arc of the sealing expansion ring and the inner arc of the exhaust port is 0.2mm. The sealing expansion ring blocks the blow-by passage formed between the exhaust chamber and the intake chamber through the axial gap between the rotor and the side cylinder head in the circumferential direction.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The triangular rotor of the present invention has multiple annular expansion grooves on both ends of its sides. These expansion grooves are arranged radially from the combustion chamber side towards the lubricating oil side of the rotor cavity. A first-stage oil-sealing expansion ring, a second-stage oil-sealing expansion ring, and a gas-sealing expansion ring are sequentially arranged along the expansion grooves. By designing the first-stage and second-stage oil-sealing expansion rings, in conjunction with the rubber rings within the oil-sealing expansion rings, the present invention effectively reduces lubricating oil leakage from the rotor cavity, while also reducing lubricating oil carbon deposits, thereby improving engine reliability and lifespan.

[0017] 2. The sealing expansion ring of this invention is radially arranged in the transition area between the side sealing plate and the sealing oil expansion ring. Its continuous annular structure forms a sealing partition in the end face gap between the rotor and the side cylinder head, precisely cutting off the end face blow-by path between the exhaust chamber and the intake chamber. Under the instantaneous condition where the rotor reaches the top dead center of the exhaust stroke and both the intake and exhaust ports are blocked, it effectively prevents exhaust gas from entering the intake chamber through the side gap. Combined with the engine's non-overlapping intake and exhaust angle design, this ensures intake air purity and optimizes combustion quality. The wear degree of the sealing oil expansion ring and the sealing expansion ring can be determined by directly measuring the axial width of the narrow lip. During engine disassembly and maintenance, only the lip width needs to be measured to determine whether replacement is necessary. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the lateral sealing structure of the triangular rotor engine of the present invention; Figure 2 This is a schematic diagram of the lateral sealing structure of the triangular rotor engine of the present invention; Figure 3 This is a schematic diagram of the structure of the present invention, showing the exhaust gas entering the intake chamber through the side cylinder head (without the sealing expansion ring); Figure 4 This is a schematic diagram of the lateral sealing structure of the triangular rotor engine with a sealing expansion ring according to the present invention. Figure 5 This is a schematic diagram of the structure of the first sealing oil expansion ring and rubber ring of the present invention; Figure 6 This is a schematic diagram of the sealing expansion ring structure of the present invention; In the above diagram, 1. Side cylinder head; 2. Rotor; 3. Air sealing ring; 4. First-stage oil sealing ring; 5. Second-stage oil sealing ring; 6. Wave spring; 7. Rubber ring; 8. Side seal; 9. Intake port; 10. Exhaust port. Detailed Implementation

[0019] To clearly illustrate the technical features of the present invention, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0020] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0021] Furthermore, in the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] Example 1 like Figure 1 and Figure 2 As shown, a composite sealing structure for lubricating oil and gas in a triangular rotor engine 2 is disclosed. The sealing structure is disposed between the engine rotor 2 and the side cylinder head 1. Multiple annular expansion grooves are respectively formed on the two ends of the triangular rotor 2. These expansion grooves are arranged radially from the combustion chamber side towards the lubricating oil side of the rotor 2's inner cavity. A first-stage oil-sealing expansion ring 4, a second-stage oil-sealing expansion ring 5, and a gas-sealing expansion ring 3 are sequentially arranged along the expansion grooves. The first-stage oil-sealing expansion ring 4 and the second-stage oil-sealing expansion ring 5 are arranged radially towards the inner cavity side of the rotor 2, while the gas-sealing expansion ring 3 is arranged radially towards the combustion chamber side. The first-stage oil-sealing expansion ring 4 and the corresponding radial inner wall of the expansion groove... A rubber ring 7 is provided between the second-stage sealing expansion ring 5 and the radial inner wall of the corresponding expansion ring groove. The rubber ring 7 is compressed radially to achieve radial lubrication seal between the sealing expansion ring and the expansion ring groove. A wave spring 6 is provided at the bottom of each expansion ring groove. The wave spring 6 abuts axially against the lower end face of the corresponding expansion ring, so that one side end face of the corresponding expansion ring is pressed against the inner surface of the side cylinder head 1. A radial fitting gap is provided between the radial outer wall of the sealing expansion ring 3 and the side wall of the corresponding expansion ring groove. The combustion gas in the combustion chamber can enter the bottom of the expansion ring groove through the radial fitting gap, forming an axial thrust to press the sealing expansion ring 3 against the inner surface of the side cylinder head 1.

[0023] In this embodiment, a wave spring 6 is provided at the bottom of the groove of the sealing expansion ring 3, and an annular sealing expansion ring 3 is installed above the wave spring 6; the wave spring 6 provides axial elastic force to axially press the top end face of the sealing expansion ring 3 against the inner surface of the side cylinder head 1; a radial fitting clearance is left between the radial outer wall of the sealing expansion ring 3 and the outer wall of the expansion ring groove, and the clearance value is less than 0.2mm.

[0024] Wave springs 6 are placed at the bottom of the expansion ring grooves. Above the wave springs 6, the second-stage sealing expansion rings 5 ​​and the first-stage sealing expansion rings 4 are installed. The second-stage sealing expansion rings 5 ​​and the first-stage sealing expansion rings 4 have the same structure. The radial inner side of both sealing expansion rings is provided with a concave annular groove, and a fluororubber ring 7 with a circular cross section is installed in the groove. After assembly, the rubber ring 7 is in a radially compressed state, with one side abutting against the inner wall of the annular groove and the other side abutting against the inner wall of the expansion ring groove, so as to achieve radial lubricating oil sealing between the sealing expansion ring and the expansion ring groove.

[0025] like Figure 3 and Figure 4 As shown, a side sealing plate 8 is circumferentially embedded at the outermost radial edge of the rotor 2 end face. The axial end face of the side sealing plate 8 is pressed against the inner surface of the side cylinder head 1, forming the first sealing defense line of the high temperature and high pressure combustion gas in the combustion chamber. The sealing gas expansion ring 3 is located radially between the side sealing plate 8 and the two-stage sealing oil expansion ring, forming the second sealing defense line of the combustion gas, together forming a two-stage combustion gas sealing structure that seals step by step.

[0026] In this embodiment, a dual seal for lubricating oil is achieved through a two-stage oil sealing ring in conjunction with a rubber ring 7, and a two-stage seal for combustion gas is achieved through a sealing gas sealing ring 3 in conjunction with a side sealing sheet 8. At the same time, the sealing gas sealing ring 3 can also block the blow-by passage between the exhaust chamber and the intake chamber, thus comprehensively improving the sealing performance of the triangular rotor 2 engine.

[0027] Example 2 like Figure 1 and Figure 2 As shown, a composite sealing structure for lubricating oil and gas in a triangular rotor engine 2 is disclosed. The sealing structure is disposed between the engine rotor 2 and the side cylinder head 1. Multiple annular expansion grooves are respectively formed on the two ends of the triangular rotor 2. These expansion grooves are arranged radially from the combustion chamber side towards the lubricating oil side of the rotor 2's inner cavity. A first-stage oil-sealing expansion ring 4, a second-stage oil-sealing expansion ring 5, and a gas-sealing expansion ring 3 are sequentially arranged along the expansion grooves. The first-stage oil-sealing expansion ring 4 and the second-stage oil-sealing expansion ring 5 are arranged radially towards the inner cavity side of the rotor 2, while the gas-sealing expansion ring 3 is arranged radially towards the combustion chamber side. The first-stage oil-sealing expansion ring 4 and the corresponding radial inner wall of the expansion groove... A rubber ring 7 is provided between the second-stage sealing expansion ring 5 and the radial inner wall of the corresponding expansion ring groove. The rubber ring 7 is compressed radially to achieve radial lubrication seal between the sealing expansion ring and the expansion ring groove. A wave spring 6 is provided at the bottom of each expansion ring groove. The wave spring 6 abuts axially against the lower end face of the corresponding expansion ring, so that one side end face of the corresponding expansion ring is pressed against the inner surface of the side cylinder head 1. A radial fitting gap is provided between the radial outer wall of the sealing expansion ring 3 and the side wall of the corresponding expansion ring groove. The combustion gas in the combustion chamber can enter the bottom of the expansion ring groove through the radial fitting gap, forming an axial thrust to press the sealing expansion ring 3 against the inner surface of the side cylinder head 1.

[0028] In this embodiment, the first-stage sealing ring 4 and the second-stage sealing ring 5 are integrally formed with a raised annular narrow lip on their axial end faces toward the side cylinder head 1. The axial width of the lip is 0.5 mm. The working surface of the narrow lip is plated with a hard chrome wear-resistant layer with a thickness of 0.02 to 0.05 mm to improve wear resistance. The top of the narrow lip is machined with an annular inclined surface with an angle α1 of 2°, which faces the lubricating oil side of the rotor 2 cavity and forms a wedge-shaped oil film inlet together with the surface of the side cylinder head 1. When the rotor 2 moves circumferentially relative to the side cylinder head 1, the annular inclined surface can provide a "wedge effect" for the lubricating oil film, allowing the lubricating oil to be drawn into the lip contact area, generating a load-bearing oil film, and reducing friction and wear. The narrow lip is similar to an "oil scraper," which can scrape excess oil between the cavity and the working wall back into the oil groove, preventing excessive lubricating oil from causing carbon deposits and making it easier for impurities to be discharged.

[0029] The narrow lip has strong self-adaptive wear capability, automatically compensating for wear and maintaining a tight seal against the side cylinder head 1. During engine disassembly and repair, the lip width Lc is measured. If the width exceeds the allowable range, the sealing ring is replaced; otherwise, it can continue to be used.

[0030] like Figure 5 As shown, the outer walls of both the first-stage sealing expansion ring 4 and the second-stage sealing expansion ring 5 are flat, contacting the outer wall of the expansion ring groove. Both the first-stage sealing expansion ring 4 and the second-stage sealing expansion ring 5 have a concave annular groove on their radially inner sides to accommodate the circular cross-section rubber ring 7. After assembly, one end of the rubber ring 7 abuts against the inner wall of the annular groove, and the other end abuts against the inner wall of the expansion ring groove, achieving radial sealing. The annular groove on the radially inner side of the first-stage sealing expansion ring 4 has a rectangular cross-section. The rubber ring 7 is made of temperature- and oil-resistant fluororubber, and its cross-sectional diameter ΦR satisfies the relationship: ΦR>(Lr-Lm+Ln), where Lr is the radial width of the expansion ring groove, Lm is the radial thickness of the sealing expansion ring, and Ln is the cross-sectional diameter of the rubber ring 7 in its free state. When the rubber ring 7 is in a compressed state within the sealing expansion ring groove, it allows the sealing expansion ring to better fit the expansion ring groove of the rotor 2, improving the sealing performance of the lubricating oil.

[0031] This embodiment further improves the lubricating sealing effect and wear resistance of the oil sealing ring, and extends the service life of the sealing structure.

[0032] Example 3 like Figure 1 and Figure 2As shown, a composite sealing structure for lubricating oil and gas in a triangular rotor engine 2 is disclosed. The sealing structure is disposed between the engine rotor 2 and the side cylinder head 1. Multiple annular expansion grooves are respectively formed on the two ends of the triangular rotor 2. These expansion grooves are arranged radially from the combustion chamber side towards the lubricating oil side of the rotor 2's inner cavity. A first-stage oil-sealing expansion ring 4, a second-stage oil-sealing expansion ring 5, and a gas-sealing expansion ring 3 are sequentially arranged along the expansion grooves. The first-stage oil-sealing expansion ring 4 and the second-stage oil-sealing expansion ring 5 are arranged radially towards the inner cavity side of the rotor 2, while the gas-sealing expansion ring 3 is arranged radially towards the combustion chamber side. The first-stage oil-sealing expansion ring 4 and the corresponding radial inner wall of the expansion groove... A rubber ring 7 is provided between the second-stage sealing expansion ring 5 and the radial inner wall of the corresponding expansion ring groove. The rubber ring 7 is compressed radially to achieve radial lubrication seal between the sealing expansion ring and the expansion ring groove. A wave spring 6 is provided at the bottom of each expansion ring groove. The wave spring 6 abuts axially against the lower end face of the corresponding expansion ring, so that one side end face of the corresponding expansion ring is pressed against the inner surface of the side cylinder head 1. A radial fitting gap is provided between the radial outer wall of the sealing expansion ring 3 and the side wall of the corresponding expansion ring groove. The combustion gas in the combustion chamber can enter the bottom of the expansion ring groove through the radial fitting gap, forming an axial thrust to press the sealing expansion ring 3 against the inner surface of the side cylinder head 1.

[0033] like Figure 6 As shown, the sealing expansion ring 3 is an annular structure. The axial end face of the sealing expansion ring 3 that contacts the side cylinder head 1 also has a narrow lip. The axial width Lc of the narrow lip on the sealing expansion ring 3 is 0.5 mm. This narrow lip reduces the contact area between the sealing expansion ring 3 and the side cylinder head 1, thereby reducing heat generation and wear, and has strong adaptive wear compensation capability. When the lip width Lc exceeds the allowable range, the sealing expansion ring 3 is replaced. One end of the narrow lip on the sealing expansion ring 3 has a 2° inclined surface α2. This inclined surface allows the gas pressure force to generate an axial component, making the sealing expansion ring 3 fit more tightly against the inner wall of the expansion ring groove, improving sealing performance. A radial fitting clearance of less than 0.2 mm is provided between the sealing expansion ring 3 and the expansion ring groove of the rotor 2. This gap can prevent the sealing expansion ring 3 from "getting stuck" in the expansion ring groove, and at the same time allow gas to enter the bottom of the expansion ring groove of the rotor 2, using gas pressure to make the sealing expansion ring 3 fit more tightly against the side cylinder head 1.

[0034] The sealing expansion ring 3 is radially arranged between the engine side sealing plate 8 and the second-stage sealing expansion ring 5, serving as a supplementary sealing function for the side sealing plate 8. The side sealing plate 8 is the first line of defense against the overflow of high-temperature and high-pressure combustion gases from the combustion chamber, and the sealing expansion ring 3, as the second line of defense, continues to prevent combustion gases from entering the rotor 2. At the same time, the sealing expansion ring 3 can also effectively prevent the gas discharged from the exhaust chamber from flowing into the intake chamber. When the triangular rotor 2 moves to the top dead center of the exhaust stroke, both the intake port 9 and the exhaust port 10 are blocked by the end face of the rotor 2. The distance between the outer arc of the sealing expansion ring 3 and the inner arc of the exhaust port 10 is 0.2mm. At this time, the sealing expansion ring 3 circumferentially blocks the blow-by channel formed between the exhaust chamber and the intake chamber through the axial clearance between the rotor 2 and the side cylinder head 1.

[0035] In this embodiment, the gas-sealing expansion ring 3 can automatically enhance the sealing effect under the action of gas pressure, and prevent it from getting stuck in the expansion ring groove, thereby improving the reliability and sealing performance of the gas-sealing expansion ring 3.

[0036] Obviously, the embodiments described above are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A composite sealing structure for lubricating oil and gas in a triangular rotor engine, the sealing structure being disposed between the engine rotor and the side cylinder head, characterized in that, Multiple annular expansion grooves are respectively formed on both ends of the triangular rotor. These expansion grooves are arranged radially from the combustion chamber side towards the lubricating oil side of the rotor cavity. A first-stage oil-sealing expansion ring, a second-stage oil-sealing expansion ring, and a gas-sealing expansion ring are sequentially arranged along the expansion grooves. The first-stage and second-stage oil-sealing expansion rings are arranged radially towards the rotor cavity, while the gas-sealing expansion ring is arranged radially towards the combustion chamber side. A rubber ring is provided between the first-stage oil-sealing expansion ring and the radial inner wall of its corresponding expansion groove. A rubber ring is also provided between the second-stage oil-sealing expansion ring and the radial inner wall of its corresponding expansion groove. A rubber ring is provided between the inner walls. The rubber ring is compressed radially to achieve a radial oil seal between the sealing expansion ring and the expansion ring groove. A wave spring is provided at the bottom of each expansion ring groove. The wave spring abuts axially against the lower end face of the corresponding expansion ring, so that one side end face of the corresponding expansion ring is pressed against the inner surface of the side cylinder head. A radial fitting gap is provided between the radial outer wall of the sealing expansion ring and the side wall of the corresponding expansion ring groove. The combustion gas in the combustion chamber can enter the bottom of the expansion ring groove through the radial fitting gap, forming an axial thrust to press the sealing expansion ring against the inner surface of the side cylinder head.

2. The composite sealing structure for lubricating oil and gas in a triangular rotor engine according to claim 1, characterized in that, Both the first-stage and second-stage oil sealing rings have narrow lip edges on their axial end faces that contact the side cylinder head. The axial width of the narrow lip edge is 0.5 mm, and the surface of the narrow lip edge is plated with a chromium-plated wear-resistant layer.

3. The oil and gas composite sealing structure for a triangular rotor engine according to claim 3, characterized in that, The top of the narrow lip edge of both the first-stage sealing oil expansion ring and the second-stage sealing oil expansion ring is provided with an annular inclined surface with an inclination angle of 2°. The annular inclined surface is used to draw lubricating oil into the lip edge contact area to form a bearing oil film when the cylinder head on the opposite side of the rotor moves circumferentially.

4. The oil and gas composite sealing structure for a triangular rotor engine according to claim 1, characterized in that, The cross-sectional diameter ΦR of the rubber ring satisfies the following relationship: ΦR > (L r -L m +L n ), where L r L is the radial width of the expansion groove. m For the radial thickness of the sealing oil expansion ring, L n The diameter of the radial section of the rubber ring in its free state; the rubber ring is made of heat- and oil-resistant fluororubber, and in the compressed state, the sealing expansion ring is pressed tightly against the inner wall of the expansion ring groove.

5. The oil and gas composite sealing structure for a triangular rotor engine according to claim 1, characterized in that, A radial fitting clearance is provided between the outer end face of the sealing expansion ring and the outer side wall of the expansion ring groove. The radial fitting clearance is less than 0.2mm, which is used to prevent the sealing expansion ring from getting stuck in the expansion ring groove and to allow gas to enter the bottom of the expansion ring groove to assist in pressing and sealing.

6. The oil and gas composite sealing structure for a triangular rotor engine according to claim 1, characterized in that, The sealing expansion ring is an annular structure. The axial end face of the sealing expansion ring that contacts the side cylinder head is provided with a narrow lip. The axial width of the narrow lip on the sealing expansion ring is 0.5mm. One end of the narrow lip on the sealing expansion ring is provided with a slope with an inclination angle of 2°, so that the sealing expansion ring is close to the inner wall of the expansion ring groove.

7. The oil and gas composite sealing structure for a triangular rotor engine according to claim 1, characterized in that, It also includes a side sealing sheet, wherein the air sealing expansion ring is arranged radially between the engine side sealing sheet and the second-stage oil sealing expansion ring; the air sealing expansion ring is used to block the air passage between the exhaust chamber and the intake chamber through the gap between the rotor and the side cylinder head.

8. The oil and gas composite sealing structure for a triangular rotor engine according to claim 1, characterized in that, The outer walls of both the first-stage and second-stage sealing expansion rings are flat and contact the outer wall of the expansion ring groove. Both the first-stage and second-stage sealing expansion rings have a concave annular groove on their radial inner side to accommodate a rubber ring with a circular cross-section. After the rubber ring is assembled, one end of the rubber ring abuts against the inner wall of the annular groove, and the other end abuts against the inner wall of the expansion ring groove, thus achieving radial sealing.

9. The oil and gas composite sealing structure for a triangular rotor engine according to claim 1, characterized in that, A side sealing plate is circumferentially embedded on the outermost radial side of the rotor end face. The axial end face of the side sealing plate is attached to the inner surface of the side cylinder head. The sealing gas expansion ring is arranged radially between the engine side sealing plate and the second-stage sealing oil expansion ring, forming a two-stage gas sealing structure with the side sealing plate to seal step by step.

10. The oil and gas composite sealing structure for a triangular rotor engine according to claim 9, characterized in that, When the triangular rotor moves to the top dead center of the exhaust stroke, and both the intake and exhaust ports are blocked by the rotor end face, the distance between the outer arc of the sealing expansion ring and the inner arc of the exhaust port is 0.2mm. The sealing expansion ring blocks the blow-by passage formed between the exhaust chamber and the intake chamber through the axial gap between the rotor and the side cylinder head in the circumferential direction.

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