A single stroke opposed piston engine with a hollow main shaft in-line supercharging duct

Abstract

The application provides a single-stroke opposed-piston engine with a hollow main shaft embedded supercharging duct, and belongs to the technical field of special internal combustion engines and aviation power devices. The single-stroke opposed-piston engine with the hollow main shaft embedded supercharging duct can solve the problem of low natural scavenging efficiency of the single-stroke opposed-piston engine under high altitude environment without increasing the external volume of the engine. The single-stroke opposed-piston engine with the hollow main shaft embedded supercharging duct comprises a body, an end cover and a hollow main shaft, the body is internally provided with a piston, and an air inlet cavity is formed between the body and the end cover; the hollow main shaft is provided with an air inlet hole in the axial direction, and the free end of the hollow main shaft is connected with the air inlet cavity.

Description

Technical Field

[0001] This invention belongs to the technical field of special internal combustion engines and aviation power units, and in particular relates to a single-stroke opposed piston engine with a hollow main shaft and an embedded supercharger duct. Background Technology

[0002] The single-stroke opposed piston engine eliminates the traditional crankshaft and valve mechanism, utilizing the interaction between the wave-shaped cam track and the piston rollers to achieve power conversion. Due to the symmetrical layout of multiple sets of opposed pistons around the central axis, this architecture has extremely high compactness and power-to-weight ratio; during the working cycle, it relies on the phase difference of the opposed pistons to sequentially open the exhaust port and intake port, thereby forming unidirectional scavenging.

[0003] This natural scavenging mechanism, which relies on exhaust pulse vacuum and external absolute atmospheric pressure, has significant limitations: when the engine is mounted on high-altitude drones or similar equipment, the airflow density drops sharply due to the precipitous decrease in ambient atmospheric pressure. The thin external air cannot create a sufficient intake pressure difference, resulting in incomplete scavenging and an extremely low intake volume coefficient, which in turn leads to poor combustion and severe power reduction. If traditional external exhaust gas turbocharging or supercharging solutions are used, it will not only significantly increase the overall size and weight of the powertrain, but also introduce complex lubrication and cooling pipelines, completely undermining the core advantage of this type of engine in terms of extreme lightweight design. Summary of the Invention

[0004] In view of this, the present invention aims to propose a single-stroke opposed piston engine with a hollow main shaft and an embedded supercharging duct, in order to solve the problem of low natural scavenging efficiency of single-stroke opposed piston engines in high-altitude environments without increasing the external volume of the engine.

[0005] To achieve the above objectives, the present invention adopts the following technical solution, providing a single-stroke opposed piston engine with a hollow main shaft and an embedded supercharging duct, comprising a body, an end cover and a hollow main shaft, wherein a piston is provided inside the body, and an intake chamber is formed between the body and the end cover; the hollow main shaft is provided with an intake hole along its axial direction, and the free end of the hollow main shaft is connected to the intake chamber.

[0006] Furthermore, the free end of the hollow spindle is connected to a pressurized micro-duct assembly, which is fixed to the end cover.

[0007] Furthermore, the booster micro duct assembly includes a stator cantilever bracket, a drive motor, and an axial flow booster impeller. One end of the stator cantilever bracket is fixedly connected to the end cover, and the other end extends axially into the hollow main shaft and is suspended in the inner cavity of the hollow main shaft. The drive motor is fixed on the stator cantilever bracket, and the axial flow booster impeller is fixed on the output shaft of the drive motor.

[0008] Furthermore, a radial rotation gap is provided between the outer edge of the axial flow booster impeller and the inner wall of the hollow main shaft.

[0009] Furthermore, the stator cantilever bracket includes an outer flange and an inner motor mount. The outer flange is fixedly connected to the end cover, and the inner motor mount is fixedly connected to the drive motor. Support ribs are arranged circumferentially between the outer flange and the inner motor mount.

[0010] Furthermore, the cross-section of the supporting rib has a teardrop shape.

[0011] Furthermore, the cross-section of the supporting rib has an airfoil-shaped streamlined structure.

[0012] Furthermore, it also includes an adaptive intake control system, which is communicatively connected to both the air pressure sensor and the drive motor to adjust the target speed of the drive motor.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Extreme space utilization: It makes groundbreaking use of the original hollow split-shaft space of the single-stroke engine, achieving zero external volume increase of the pressurization system, which meets the stringent space and weight requirements of aircraft such as drones.

[0014] 2. Decoupling of scavenging performance: The independent electric micro-duct eliminates the dependence of mechanical supercharging on the speed of the hollow spindle, and can actively provide high-density positive pressure air intake, significantly improving the charging efficiency in thermodynamic cycles.

[0015] 3. Fluid dynamics optimization: The internal streamlined support rib design effectively reduces turbulence and boundary layer drag loss generated when high-speed airflow is drawn in. Attached Figure Description

[0016] Figure 1 This is an enlarged cross-sectional view of the hollow spindle front end embedded duct structure of the present invention; Figure 2 This is a three-dimensional structural diagram of the supercharged micro-duct assembly and hollow spindle assembly of the present invention; Figure 3 This is a diagram of the external structure of the present invention; Figure 4 This is a schematic diagram of a single-stroke opposed piston engine.

[0017] In the figure: 10 - end cover; 20 - hollow spindle; 110 - stator cantilever bracket; 120 - drive motor; 130 - axial flow booster impeller; 100 - assembly position of the hollow spindle front end embedded duct structure. Detailed Implementation

[0018] See appendix Figures 1 to 4This embodiment provides a single-stroke opposed piston engine with a hollow main shaft and an embedded supercharging duct, comprising: an externally stationary engine end cap 10 that does not rotate, and an internally rotating hollow main shaft 20 driven by a piston.

[0019] The supercharged micro-duct assembly is suspended and embedded inside the intake end of the hollow main shaft 20. Specifically, the outer flange of the stator cantilever bracket 110 is rigidly fixed to the stationary end cover 10 of the engine by fastening bolts. The stator cantilever bracket 110 has several support ribs, the cross-section of which is designed as an airfoil-shaped streamlined structure, converging towards the center and connecting to the inner motor mount.

[0020] The drive motor 120 is fixedly clamped in the inner motor housing. The axial flow booster impeller 130 is mounted on the output shaft of the drive motor 120. In terms of assembly, a specific radial aerodynamic rotational clearance is reserved between the outer edge of the axial flow booster impeller 130 and the smooth inner wall of the hollow main shaft 20. This clearance ensures both fluid sealing to reduce tip leakage and prevents mechanical interference with the booster duct that operates independently of the main shaft.

[0021] During engine operation, the drive motor 120, which is in operation, drives the booster impeller 130 to rotate independently at high speed. The external atmosphere first passes through the streamlined support ribs of the stator cantilever bracket 110, where the boundary layer transitions smoothly, minimizing airflow resistance. Subsequently, the air is drawn into the axial-flow booster impeller 130 for pressurization, increasing the kinetic and pressure potential energy of the airflow. The drive motor 120 is a high-speed brushless DC motor.

[0022] The pressurized, high-density air flows through the sealed channel formed inside the hollow main shaft 20, reaching the intake port of the cylinder under high pressure. At this time, due to the positive pressure actively established on the intake side, when the opposed pistons alternately open the exhaust and intake ports, the high-density intake charge can powerfully sweep out the residual exhaust gas in the cylinder, completing a highly efficient one-way scavenging process and providing sufficient air mass for the next compression and combustion stroke.

[0023] As a preferred implementation, to adapt to complex flight conditions, the engine booster system is also connected to an adaptive intake control system. This system includes a pressure sensor and a control unit. The control unit has a pre-established mapping model between different altitudes and the engine's optimal intake compensation. During flight, the system collects external pressure data in real time. When the pressure drops, the control algorithm calculates the required target intake pressure and outputs a corresponding speed control signal to the drive motor 120. As the altitude increases, the impeller speed increases adaptively, forming a precise closed-loop fluid control compensation, enabling the engine to maintain stable power output. The specific control logic is existing technology and will not be described in detail here. The pressure sensor is installed on the outer surface of the engine stationary end cover (10) and is adjacent to the intake of the booster micro-duct assembly.

[0024] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A single-stroke opposed piston engine with a hollow main shaft and embedded supercharging duct, comprising a body, end caps (10) and a hollow main shaft (20), wherein a piston is disposed inside the body, characterized in that, An air intake chamber is formed between the body and the end cover (10); the hollow main shaft (20) is provided with an air intake hole along its axial direction, and the free end of the hollow main shaft (20) is connected to the air intake chamber.

2. A single-stroke opposed piston engine with a hollow main shaft and embedded supercharger duct according to claim 1, characterized in that: The hollow spindle (20) is connected to a pressurized micro duct assembly at its free end, and the pressurized micro duct assembly is fixed on the end cap (10).

3. A single-stroke opposed piston engine with a hollow main shaft and embedded supercharging duct according to claim 2, characterized in that: The booster micro duct assembly includes a stator cantilever bracket (110), a drive motor (120), and an axial flow booster impeller (130). One end of the stator cantilever bracket (110) is fixedly connected to the end cover (10), and the other end extends axially into the hollow main shaft (20) and is suspended in the inner cavity of the hollow main shaft (20). The drive motor (120) is fixed on the stator cantilever bracket (110), and the axial flow booster impeller (130) is fixed on the output shaft of the drive motor (120).

4. A single-stroke opposed piston engine with a hollow main shaft and embedded supercharging duct according to claim 3, characterized in that: A radial rotation gap is provided between the outer edge of the axial flow booster impeller (130) and the inner wall of the hollow main shaft (20).

5. A single-stroke opposed piston engine with a hollow main shaft and embedded supercharging duct according to claim 4, characterized in that: The stator cantilever bracket (110) includes an outer flange and an inner motor mount. The outer flange is fixedly connected to the end cover (10), and the inner motor mount is fixedly connected to the drive motor (120). Support ribs are arranged circumferentially between the outer flange and the inner motor mount.

6. A single-stroke opposed piston engine with a hollow main shaft and embedded supercharging duct according to claim 5, characterized in that: The cross-section of the supporting rib is teardrop-shaped.

7. A single-stroke opposed piston engine with a hollow main shaft and embedded supercharging duct according to claim 5, characterized in that: The cross-section of the supporting rib has an airfoil-shaped streamlined structure.

8. A single-stroke opposed piston engine with a hollow main shaft and embedded supercharger duct according to any one of claims 1 to 7, characterized in that: It also includes an adaptive intake control system, which is communicatively connected to the air pressure sensor and the drive motor (120) to adjust the target speed of the drive motor (120).

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