Through-shaft double-swash-plate opposite-piston two-stroke internal combustion engine

Abstract

The invention discloses a through-shaft double-swash-plate opposite-piston two-stroke internal combustion engine, and relates to an axial engine. The power platform is composed of a through shaft swash plate movement mechanism and a multifunctional two-stroke internal combustion engine piston assembly (shown in patent application), and the power platform which is high in power density, stable and reliable is obtained. According to the basic method, two sets of swash plate movement mechanisms 2 are arranged on a main shaft 1, a cylinder sleeve 35 and a power cylinder of a multifunctional two-stroke internal combustion engine piston assembly 3 of two opposite pistons are arranged, a center shaft is parallel to the main shaft 1, and a plurality of power cylinders are distributed around the circumference of the main shaft 1. According to the structural layout of the internal combustion engine, the space size is reduced, large cylinder displacement, motion self-balance, independent lubrication and uniflow scavenging are obtained, and the internal combustion engine is suitable for a homogeneous mixed gas pressure combustion technology of various fuels and all working conditions.

Description

Technical Field

[0003] This invention belongs to the field of internal combustion engine engineering, and relates to an axial engine and a flexible combustion chamber, the power-to-weight ratio of the internal combustion engine, its operational stability and reliability, specifically in three aspects: thermal efficiency, mechanical functional component structural combination, and spatial structural size utilization. Background Technology

[0005] To overcome the development goals of achieving a power-to-weight ratio greater than 3 kW / daN and a fuel consumption rate less than 235 g / kWh for general aviation piston engines, and to address the challenges of low thermal efficiency, high vibration, and unstable micro-combustion operation in portable micro-internal combustion engines, this invention proposes a solution. The conventional internal combustion engine structure, with cylinders arranged radially along the output crankshaft, is simple in structure, easy to machine, and widely used in scenarios where power density requirements are not high. However, when emphasizing the power-to-weight ratio, the space utilization of the cylinder layout perpendicular to the crankshaft in conventional internal combustion engines is low, the utilization rate of manufacturing materials is low, and the additional space occupied by motion balancing mechanisms and cooling / lubrication devices makes it difficult to reduce the engine's mass. Crucially, the low compression ratio and low thermal efficiency represent a bottleneck in improving the power-to-weight ratio of conventional internal combustion engines. Under the requirements of miniaturization or ultra-miniaturization of internal combustion engines, the small distance between the combustion chamber formed by the hot wall of the piston top and the cold wall of the cylinder head results in a cooling of the air-fuel mixture compression temperature. This leads to a high probability of misfires and irregular combustion, resulting in significant operational vibration, high fuel consumption, and low thermal efficiency. Reducing engine size is severely limited by the flameout caused by the cold wall of the small combustion chamber. Research indicates that the combustion environment of the constant-volume combustion chamber in modern internal combustion engines is the core issue limiting low thermal efficiency, and that optimizing and integrating the internal combustion engine structure is crucial. Changing the combustion environment and optimizing the internal combustion engine structure are the background technical requirements of this invention. Summary of the Invention

[0007] In the overall layout of the axial engine, two through-shaft swashplate motion mechanisms are set on a main shaft, which drive multiple opposing piston assemblies 3 of two multifunctional two-stroke internal combustion engines of the same mass to reciprocate around the circumference of the main shaft, forming a flexible combustion chamber and its high compression ratio combustion environment. The motion mechanism is constructed with cylindrical sleeve motion pairs to improve thermal efficiency, mechanical efficiency and space utilization, thereby increasing the power-to-weight ratio of the internal combustion engine.

[0008] To achieve the above objectives, the comprehensive solution of the present invention is as follows: On a main shaft 1, two identical swashplate motion mechanisms 2 are set to form a main shaft assembly, including two opposing multifunctional two-stroke internal combustion engine piston assemblies 3 and cylinder liners 35 forming a power cylinder. Its central axis is parallel to the main shaft 1, and several power cylinders are evenly distributed around the circumference of the main shaft 1. The assembly includes an engine body 4, an upper engine body 5, a lower engine body 6, an upper end cover 7, a lower end cover 8, an intake chamber 9, a valve 10, an oil valve 11, an oil pump 12, and an oil cooler 13, including an intake port 27, an exhaust port 28, an air passage 32, a scavenging chamber 33, and a valve port 34, thus constructing an axial two-stroke engine.

[0009] The main shaft 1 is equipped with two swashplate motion mechanisms 2 to form a main shaft assembly. The assembly includes two swashplate motion structures 2 with equal angles, opposite directions, and identical mass and shape on the main shaft 1, a step that is locked onto the main shaft 1, and two fixing nuts 24 that fix it. The assembly includes a timing valve 11 and an oil pump 12 that rotate with the main shaft 1, two axial retaining rings 25 and rolling bearings 26. The assembly includes an upper body 5, a lower body 6, an upper end cover 7, and a lower end cover 8 that fix the rolling bearings 26. The assembly includes a swashplate shaft 31 that is connected to a multifunctional two-stroke internal combustion engine piston assembly 3 via a cylindrical sleeve motion pair. The assembly includes four swashplate holders 16 that rotate with the main shaft assembly and generate torque self-balancing force due to centrifugal force.

[0010] The two opposing, multi-functional two-stroke internal combustion engine piston assemblies 3 include a cross 22 rigidly connected to a scavenging piston 23 within an O-ring spring 21, a fixed O-ring spring 21, a piston top 18 fixed to a piston skirt 20, and a radially movable, non-opening piston ring 19 clamped therein. The piston skirt 20 presses the O-ring spring 21 pre-tightly and is elastically connected to the other end of the cross 22. The piston skirt 20 has a spring working stroke. The opposing piston tops 18 of the two piston assemblies 3 form a flexible combustion chamber, providing a high compression ratio combustion environment and a minimum cold wall surface thermal environment. The O-ring spring 21 is set to enter the cylinder liner 35 using the piston stroke space. The scavenging piston 23, together with the upper engine body 5, lower engine body 6, upper end cover 7, and lower end cover 8, form two scavenging chambers 33. The system includes a cylindrical sleeve kinematic pair with three-dimensional spatial coordinates set in the middle of the cross 22, corresponding to the three-dimensional movement of the swashplate shaft 31, realizing the reciprocating motion of the piston assembly 3. It also includes two opposing, multi-functional two-stroke internal combustion engine piston assemblies 3 with equal mass and opposite directions of motion, whose reciprocating inertia cancel each other out. A non-opening piston ring 19 controls the leakage rate of high-pressure gas, ensuring a high-pressure working environment. The flexible combustion chamber described herein is a process in which the O-ring spring 21 undergoes compression or rebound when the working fluid compression pressure or combustion pressure exceeds the preload pressure of the O-ring spring 21. The thermodynamic state of the volume, pressure, and temperature of the flexible combustion chamber follows the characteristics of spring stiffness. The working stroke of the O-ring spring 21 provides the domain of thermodynamic state change, providing a high compression ratio operating environment and a way to improve thermal efficiency, and adapting to various fuels and homogeneous mixture compression ignition technology.

[0011] The swashplate motion mechanism 2 assembly includes two swashplate holders 16 and two balls and their retainers 17 that clamp the swashplate 15 relative to each other. Two sets of rolling bearings constrain the swashplate 15 to form a rotational motion pair. The mechanism includes maintaining the central axis of the swashplate 15 at an angle θ with the axis of the main shaft 1, allowing the main shaft 1 to pass through. The two swashplate holders 16 are engaged on the main shaft 1 and rotate with the main shaft 1. The swashplate 15 does not rotate with the main shaft 1 and generates its own oscillating motion. The swashplate shaft 31 oscillates back and forth. The swashplate 15 is radially and evenly arranged with the swashplate shaft 31 connected to the intermediate cylindrical sleeve motion pair of the cross 22.

[0012] The scavenging process of the multi-functional two-stroke internal combustion engine piston assembly 3 with two opposing pistons is as follows: During the compression stroke, the piston skirt 20 closes the scavenging port 27 and the exhaust port 28. Air mixes with fuel through the intake port 36. The mixture is drawn into the intake chamber axially by the main shaft 1, through the upper end cover 7, and through the valve port 34 that opens at the time of the valve 10 as the main shaft 1 rotates. The mixture passes through the scavenging chamber 9, the upper engine body 5, the lower engine body 6, and the air passages 32 arranged on the engine body 4, and is drawn into the scavenging chamber by the two scavenging pistons 23. 33; Before the power piston of each cylinder reaches the bottom dead center during its power stroke, one end of the power piston opens the exhaust port 28 of the cylinder liner 35 to allow the high-pressure combustion gas to be discharged, and then the other end of the power piston opens the scavenging port 27. The scavenging piston 23 presses in the mixture and then enters the scavenging port 27 on the cylinder liner 35 through the air passage 32 to remove the combustion exhaust gas. The combustion exhaust gas is discharged from the body through the exhaust port 28 on the cylinder liner 35 and the exhaust chamber of the lower engine block 6. This includes utilizing the space between the circumferential distribution of each cylinder liner 35 to configure the air passage 32 and its scavenging port 27 of each cylinder liner 35.

[0013] The air-fuel ratio adjustment method of the air intake chamber 9 and the oil valve 11 is that the fuel is controlled by the rotating oil valve 11 to control the flow area and flow rate of the fuel, and is drawn in and mixed with high-speed air through the air intake port 36.

[0014] The lubrication of the motion mechanism consisting of the oil pump 12 and the oil cooler 13 is a closed and independent circulating cooling lubrication and filtration. It includes two sets of swashplate motion mechanisms 2 with inlet and outlet ports connected to the oil cooler 13. The rotating spindle 1 drives the oil pump to generate an oil flow pressure difference. The oil circulates into the oil cooler 13 through the motion space of the two sets of swashplate motion mechanisms 2 connected to the spindle 1. The engine body 4 has a cooling surface on its outer side to balance the temperature of the cylinder liner 35 when the internal combustion engine is working.

[0015] The beneficial effects of the above solution are:

[0016] 1. The overall layout of the internal combustion engine boasts high space utilization, small axial structural dimensions, and ample room for expansion. Based on the principle that a circle has the largest area and the smallest circumference, by fully utilizing the 360° space around the power output shaft 1 of the internal combustion engine, multiple cylinders can be compactly arranged within a minimal space, increasing the power output per unit volume and the utilization rate of metal materials. A single shaft 1 running through the internal combustion engine can be extended for multiple configurations and combinations, expanding the engine's displacement.

[0017] 2. The functional components have a compact structure, high integration, and high thermo-mechanical integration. For example, in the cylinder liner 35, two sets of opposing piston assemblies 3 form an ideal flexible combustion chamber for direct scavenging and self-controlled combustion. The opposing piston tops 18 have hot walls, which reduce the impact of cold wall flameout and improve combustion stability, doubling the exhaust volume. Functional components are set up using the reciprocating motion space. The two sets of motion inertia are opposite, canceling the motion inertia and eliminating the need for dynamic balancing components. Opposite scavenging pistons 23 provide scavenging pressure and motion guidance. The valve 10, which rotates with the main shaft 1, provides timing scavenging and the oil pump 12 provides oil circulation pressure. The swashplate holders 16 set in opposite directions provide even-even self-balancing centrifugal torque. The swashplate 15's rolling motion space utilizes the idle space of each cylinder layout to form a lubricating oil space. In the engine block 4 and the upper and lower engine blocks 5 and 6, the gaps between multiple cylinder liners 35 and scavenging chambers 33 are provided with air passages 32 and exhaust ports 28.

[0018] 3. The self-controlled combustion technology of the flexible combustion chamber is adapted to high compression ratio combustion and various fuels and their homogeneous mixture compression ignition technology, which provides a guarantee for achieving high thermal efficiency and power density and their application, and simplifies or eliminates the fuel ignition system.

[0019] 4. The reciprocating inertial force and rotational torque are completely balanced, resulting in smooth operation and a reasonable stress distribution in the structure.

[0020] 5. A sealed, independent lubrication system provides excellent lubrication and cooling, improving the reliability and durability of moving parts. Attached Figure Description

[0022] Figure 1 Through-shaft double swashplate opposed piston two-stroke internal combustion engine

[0023] Figure 2 Spindle assembly

[0024] Figure 3 Swashplate Motion Mechanism

[0025] Figure 4 Multifunctional Piston Assembly Detailed Implementation

[0027] The following detailed description of the embodiments, in conjunction with the accompanying drawings, further illustrates the present invention.

[0028] Figure 1 The through-shaft double swashplate opposed piston two-stroke internal combustion engine is an axial engine. The term "through-shaft" refers to the main shaft 1 running through the entire engine. Two sets of swashplate motion structures 2 are arranged at opposite angles on the main shaft 1. Multiple swashplate shafts 31 are mounted on the swashplates 15 (see...). Figure 3The two sets of piston assemblies 3 in the cylinder liner 35, which are arranged parallel to the main shaft 1, form a cylindrical sleeve kinematic pair with the cross 22 in the piston assembly 3. The piston tops 18 of the two sets of piston assemblies 3 (see...) Figure 4 The pistons are arranged opposite each other in the cylinder liner 35, forming a flexible combustion chamber with minimal cold wall surface. The rotation of the main shaft 1 drives the swashplate holder 16 to rotate, forcing the relatively fixed swashplate 15 to produce a rolling motion. The swashplate shaft 31 reciprocates, driving the two sets of piston assemblies 3 to reciprocate in opposite directions (see...). Figure 2 , Figure 3 An intake port 27 and an exhaust port 28 are provided on the cylinder liner 35 to form a direct scavenging system for the two-stroke engine. In the upper engine block 5, engine block 4, and lower engine block 6, multiple cylinder liners 35 are evenly arranged around the main shaft 1, with air passages 31 connecting the scavenging chambers 33 and scavenging ports 27 of the scavenging pistons 23 on the two sets of piston assemblies 3. During the compression stroke of the piston assembly 3, the piston skirt 20 closes the scavenging ports 27 and the exhaust port 28. The scavenging piston 23 draws in air from the valve port 34 opened by the valve 10. The air is then drawn in through the smallest diameter throat of the intake port 36 to mix with fuel. The air-fuel ratio of the mixture is adjusted by the fuel flow area of ​​the fuel valve 11. During the power stroke of piston assembly 3, valve 10 rotates to close valve port 34, and scavenging piston 23 compresses the air-fuel mixture in scavenging chamber 33. Before the bottom dead center of the power stroke of piston assembly 3, one set of piston assemblies 3 first opens exhaust port 28 to allow combustion exhaust gas to be discharged. Subsequently, another set of piston assemblies 3 opens scavenging port 27 to allow the compressed air-fuel mixture to enter cylinder liner 35, scavenging the combustion exhaust gas. Because the upper engine block 5, engine block 4, and lower engine block 6 form a relatively closed space with piston assembly 3 for power stroke and scavenging and its air passage 32, two sets of swashplate motion structures 2 are located in independent sealed spaces. The sealed spaces are provided with passages to oil cooler 13, including oil pump 12 providing circulation pressure, forming an independent lubrication system.

[0029] Figure 2 Main spindle assembly. The main spindle 1 shown is continuous. First, the oil pump 12 is locked onto the main spindle 1, then the inner swashplate holder 16 of the two sets of swashplate motion mechanisms 2 with opposite angles (θ) is locked. Two fixing nuts 24 respectively abut against the outer swashplate holder 16, two axial retaining rings 25 respectively block the fixing nuts 24, the inner rings of the two rolling bearings 26 respectively abut against the axial retaining rings 25, and the outer rings of the rolling bearings 26 are respectively abutted by the upper end cover 7 and the lower end cover 8, thus fixing the main spindle assembly. When the main spindle 1 rotates, the air valve 10 fixed on the main spindle 1 opens or closes at the appropriate time for the intake and scavenging of each cylinder surrounding the main spindle 1. The oil pump 12 fixed on the main spindle 1 provides oil flow pressure. The four swashplate holders 16 fixed on the main spindle 1 respectively push two swashplates 15 to roll and swing in opposite directions. The two swashplate shafts 31 in each cylinder liner 35 swing in opposite directions. The two sets of piston assemblies 3 in the cylinder liner 35 (see...) Figure 1 , 4The inertial forces of the opposing reciprocating motion cancel each other out, and the opposing piston tops 18 provide the minimum cooling surface. The centrifugal forces generated by the four swashplate holders 16 rotating with the main shaft 1, which are offset from the main shaft 1, cancel each other out. Five swashplate shafts 31 are set on the two sets of swashplates 15 in the figure, and five cylinder liners 35 are set at 72° intervals around the main shaft 1. Each swashplate shaft 31 is equipped with a cylindrical sleeve kinematic pair component, which is assembled on ten pairs of opposing piston assemblies 3 (see...). Figure 4 On the cross 22 in ) .

[0030] Figure 3 Swashplate motion mechanism. In swashplate motion mechanism 2, the two swashplate holders 16 should be engaged at the corresponding steps of the main shaft 1 (see...). Figure 2 Two sets of balls and cages 17 are clamped on the two end faces of the swashplate 15. The central axis of the swashplate 15 intersects the spindle 1's spindle at a fixed angle θ, and the swashplate 15 is in a state of one degree of rotational freedom. When the radial swashplate shaft 31 on the swashplate 15 is in a plane that is fixed relative to the axis of the spindle 1, the spindle 1 rotates one revolution, the swashplate 15 rolls one revolution, the swashplate shaft 31 oscillates once, and the piston assembly 3 reciprocates once, realizing two strokes. Conversely, it drives the spindle 1 to rotate one revolution. In the figure, the swashplate 15 is equipped with five swashplate shafts 31, corresponding to the five piston assemblies 3 in the cylinder liner 35.

[0031] Figure 4A multi-functional piston assembly. The cross-shaped piston 22 has a power piston and a scavenging piston 23 coaxially opposed at both ends. The power piston includes a piston crown 18 and a piston skirt 20 that holds a closed piston ring 19. The closed piston ring 19 moves radially to fit the cylinder liner 35, controlling the working fluid leakage. The length of the piston skirt 20 is designed to keep the power piston closed at top dead center, closing the scavenging port 27 and exhaust port 28. A universal piston ring and a pin groove through which a locating pin can pass can be provided. The length of the pin groove determines the spring's working stroke. The piston skirt 20 presses against the O-spring 21, creating a pre-deformation, and elastically connects to the cross-shaped piston 22. The piston crown 18 forms a flexible combustion chamber. At the other end of the cross-shaped piston 22, a locating pin passes through a locating pin hole on the scavenging piston 23, rigidly connecting the O-spring 21 to the cross-shaped piston 22. A cylindrical sleeve kinematic pair component of a swashplate shaft 31 is arranged in the middle of the cross-shaped piston 22, forming three cylindrical sleeve kinematic pairs to accommodate the three rotations and three movements generated by the swashplate shaft 31's oscillation. The cross-shaped piston 22 is positioned in the middle of the O-spring 21. During the compression stroke, the compression pressure in the flexible combustion chamber is less than the preload of the O-spring 21, resulting in adiabatic compression of the working fluid. Before the piston reaches top dead center, the cross 22 remains relatively stationary. When the compression or combustion pressure in the flexible combustion chamber exceeds the preload of the O-spring 21, the O-spring 21 is compressed, increasing the volume of the flexible combustion chamber formed by the piston top 18. After the piston reaches top dead center, when the combustion pressure is at its maximum, the O-spring 21 achieves its maximum working stroke, and the flexible combustion chamber volume reaches its maximum. Before the expansion process, when the pressure in the flexible combustion chamber is less than the rebound force of the O-spring 21, the O-spring 21 returns the absorbed mechanical work, increasing the internal energy of the working fluid. The changes in combustion pressure and volume in the flexible combustion chamber follow the characteristics of spring stiffness, controlling the heating process to ensure combustion stability and increase the internal energy of the working fluid. This provides a solution for improving the thermal efficiency of internal combustion engines by adopting high compression ratios and homogeneous mixture compression ignition technology.

Claims

1. A through-shaft double swashplate opposed piston two-stroke internal combustion engine is characterized in that two sets of swashplate motion mechanisms 2 are set on a main shaft 1 to form a main shaft assembly, and a multi-functional two-stroke internal combustion engine piston assembly 3 including two opposed pistons forms a power cylinder, including a power cylinder spindle parallel to the main shaft 1, and several power cylinders are evenly distributed around the circumference of the main shaft 1, including an engine body 4, an upper engine body 5, a lower engine body 6, an upper end cover 7, a lower end cover 8, an intake chamber 9, an oil cooler 13, including a scavenging port 27, an exhaust port 28, an air passage 32, a scavenging chamber 33, a cylinder liner 35, an intake port 36, and a heat dissipation surface is provided on the outer side of the engine body 4.

2. The spindle assembly according to claim 1 is characterized in that the spindle 1 is provided with two swashplate motion structures 2 with equal angles, opposite directions and the same mass and shape, comprising a timing valve 10 and an oil pump 12, two fixing nuts 24, two axial retaining rings 25 and two rolling bearings 26, and including an upper body 5, a lower body 6, an upper end cover 7, a lower end cover 8 to fix the rolling bearings 26.

3. The characteristic of the kinematic pair connecting the swashplate motion mechanism 2 and the piston assembly 3 according to claim 1 is that the kinematic pair is connected by a cylindrical sleeve.

4. The intake and exhaust characteristics of a power cylinder according to claim 1 are that the air valve 10 fixed on the main shaft 1 rotates to allow air intake and direct current scavenging.

5. The scavenging chamber 33 and scavenging piston 23 as described in claim 1 constitute a stroke volume feature in that the upper end cover 7 and the upper body 5, the lower end cover 8 and the lower body 6, together with the two scavenging pistons 23, form two scavenging chambers 33, including a guide for the reciprocating motion of the piston assembly 3.

6. The motion bearing of the swashplate motion mechanism 2 according to claim 1 is a rolling bearing.

7. The air-fuel ratio adjustment feature of the intake chamber 9 and the oil valve 11 as described in claim 1 is that rotating the oil valve 11 controls the flow area of ​​the fuel and adjusts the air-fuel mixture ratio at the intake port 36.

8. The lubrication feature of the motion mechanism consisting of the oil pump 12 and the oil cooler 13 as described in claims 1 and 2 is a closed-loop circulating cooling lubrication, including the rotation of the main shaft 1 driving the oil pump to generate an oil flow pressure difference, the oil passing through a channel set between the machine body 4 and the main shaft 1 to lubricate and cool the moving parts of the two swashplate motion mechanisms 2 and their piston assemblies 3, and circulating cooling and filtration purification through the oil cooler 13.

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