Independent lubricating system for aviation piston engine

Abstract

The utility model discloses an independent lubricating system for an aviation piston engine, belongs to the technical field of engines, and is suitable for a two-stroke in-cylinder direct injection piston engine. The lubricating system comprises a lubricating oil tank, a first lubricating oil way, a second lubricating oil way and an electronic control unit. The first lubricating oil way provides lubricating oil for two air cylinders of the engine, and the second lubricating oil way provides lubricating oil for an air pump assembly and a crankcase of the engine. The electronic control unit is electrically connected with the electronic lubricating oil pumps in the two lubricating oil ways and used for controlling the working frequency of the two electronic lubricating oil pumps, and then the pump-out flow is controlled. The lubricating oil access points are arranged on the two air cylinders, the crankcase and the air pump assembly of the engine, the two lubricating oil ways capable of being independently controlled are designed to be communicated with the lubricating oil tank and the lubricating oil access points, the different lubricating oil ways can work independently, the oil amount is controllable, and therefore low-consumption and high-efficiency independent lubrication is achieved; the weight and the size of the lubricating system are reduced.

Description

Technical Field

[0001] This invention belongs to the field of engine technology, specifically relating to an independent lubrication system for an aircraft piston engine. Background Technology

[0002] Two-stroke aero engines typically employ carburetor or port injection fuel supply methods, using mixed lubrication where lubricating oil is dissolved in the fuel in a specific ratio to lubricate the engine's moving parts. Aero piston engines operate under high load and high speed conditions for extended periods, placing high demands on the lubrication of the crankshaft, connecting rod mechanism, and piston-cylinder interface. However, with direct injection technology, fuel is injected directly into the combustion chamber, failing to provide the necessary lubrication to moving parts such as the main bearings and connecting rod bearings within the crankcase. Therefore, a highly efficient and reliable lubrication system must be designed to provide the necessary lubricating oil for engine operation. Furthermore, the extremely stringent weight requirements of aero piston engines necessitate exceptionally high efficiency from the lubrication system.

[0003] Existing direct-injection piston engines employ splash lubrication or pressure lubrication systems, which deliver lubricating oil from the crankcase to various lubrication points within the engine through the movement of internal engine components. These lubrication systems are complex, heavy, and bulky, making them unsuitable for the stringent weight requirements of aero-engine piston engines. Furthermore, the centralized control of these systems prevents targeted lubrication or metered lubrication of specific areas, resulting in low lubrication efficiency, high oil consumption, and the need for large oil volumes, further increasing the size and weight of the lubrication system. Summary of the Invention

[0004] The technical problem to be solved:

[0005] To overcome the shortcomings of existing technologies, this invention provides an independent lubrication system for aircraft piston engines. Lubricating oil access points are set in the two cylinders, crankcase, and air pump assembly of the engine. Two independently controllable lubrication oil circuits are designed to connect the oil tank and each lubrication oil access point. The amount of lubricating oil in different lubrication oil circuits is controllable, achieving low consumption and high efficiency independent lubrication, and reducing the weight and volume of the lubrication system.

[0006] The technical solution of the present invention is: an independent lubrication system for an aircraft piston engine, comprising an oil tank, a first lubrication oil passage, a second lubrication oil passage, and an electronic control unit;

[0007] The oil tank provides lubricating oil to two lubrication lines;

[0008] The first lubrication circuit is used to supply lubricating oil to the two cylinders of the engine. The first lubrication circuit includes a first electronic lubricating oil pump, which is used to supply lubricating oil in the lubricating oil tank to the first lubrication circuit.

[0009] The second lubrication circuit is used to supply lubricating oil to the engine's air pump assembly and crankcase. The second lubrication circuit includes a second electronic oil pump, which supplies lubricating oil from the oil tank to the second lubrication circuit.

[0010] The electronic control unit is electrically connected to each of the two electronic lubricating oil pumps and is used to control the operating frequency of the two electronic lubricating oil pumps to control the flow rate.

[0011] A further technical solution of the present invention is as follows: the first lubricating oil circuit further includes a first oil check valve and a first three-way valve; the inlet of the first electronic lubricating oil pump is connected to the lubricating oil tank through an oil pipe, and the outlet of the first electronic lubricating oil pump is connected to the inlet of the first oil check valve through an oil pipe; the outlet of the first oil check valve is connected to the inlet of the first three-way valve through an oil pipe, and the first oil check valve is used to prevent the lubricating oil in its oil circuit from flowing back; one outlet of the first three-way valve is connected to the lubricating oil hole of the first cylinder through an oil pipe, and the other outlet of the first three-way valve is connected to the lubricating oil hole of the second cylinder through an oil pipe, respectively for lubricating the first cylinder and the second cylinder.

[0012] A further technical solution of the present invention is as follows: the second lubricating oil circuit further includes a second oil check valve and a second three-way valve; the inlet of the second electronic lubricating oil pump is connected to the lubricating oil tank through an oil pipe, and the outlet of the second electronic lubricating oil pump is connected to the inlet of the second oil check valve through an oil pipe; the outlet of the second oil check valve is connected to the inlet of the second three-way valve through an oil pipe, and the second oil check valve is used to prevent the lubricating oil in its oil circuit from flowing back; one outlet of the second three-way valve is connected to the lubricating oil hole of the air pump assembly through an oil pipe, and is used to lubricate the bearing inside the air pump assembly; the other outlet of the second three-way valve is connected to the lubricating oil hole of the crankcase through an oil pipe, and is used to lubricate the inside of the crankcase.

[0013] A further technical solution of the present invention is: the lubricating oil hole of the first cylinder and the lubricating oil hole of the second cylinder are respectively provided on the cylinder head of the first cylinder and the cylinder head of the second cylinder.

[0014] A further technical solution of the present invention is: the lubricating oil hole of the air pump assembly is provided on the outer housing of the air pump assembly, located at the outer housing corresponding to the eccentric gear mounting part inside the air pump assembly.

[0015] A further technical solution of the present invention is that the oil hole of the crankcase is located at the upper end of the crankcase of the engine.

[0016] A further technical solution of the present invention is that the oil pipes connected to each section of the first lubrication oil circuit and the second lubrication oil circuit are arranged outside the engine and can be bent arbitrarily.

[0017] A further technical solution of the present invention is that the independent lubrication system is applied to a two-stroke direct injection piston engine.

[0018] Beneficial effects

[0019] The beneficial effects of this invention are as follows: This invention provides an independent lubrication system for aircraft piston engines, suitable for two-stroke direct-injection piston engines. By setting lubrication holes at four points on the engine requiring lubrication, lubricating oil from the oil tank is led out through two main lubrication lines (i.e., the first lubrication line and the second lubrication line). Each main lubrication line is then divided into two branch lines by a three-way valve. The two branch lines of the first lubrication line are connected to the two cylinder blocks of the engine, and the two branch lines of the second lubrication line are connected to the air pump assembly and the crankcase, respectively, thereby achieving targeted lubrication at the four engine points. Simultaneously, the electronic oil pumps in both the first and second lubrication lines are controlled by an electronic control unit, enabling independent operation control and lubrication flow control for both lines. This allows for adjustment of the oil flow according to the lubrication needs of different engine components, resulting in low-consumption and high-efficiency lubrication.

[0020] Compared with the prior art, the present invention has the following main advantages:

[0021] 1. This lubrication system establishes four lubrication circuits for point-to-point lubrication: from the oil tank to the two cylinder blocks, from the oil tank to the crankcase, and from the oil tank to the air pump assembly. These circuits are individually controlled by two electronic oil pumps, allowing for separate lubrication of the two cylinder block circuits or simultaneous, separate lubrication of the crankcase and air pump assembly circuits. Compared to traditional lubrication systems, this invention can control the first and second lubrication circuits separately as needed, reducing fuel injection consumption, improving lubrication efficiency, and indirectly reducing the amount of lubricating oil required, thus lightening the engine weight.

[0022] 2. Compared with traditional aircraft engine lubrication systems, this invention provides point-to-point lubrication for the bearing at the eccentric gear mounting point in the air pump assembly. The lubricating oil is sprayed to various parts inside the crankcase through the high-speed rotation of the eccentric gear. In conjunction with the point-to-point lubrication of the crankcase in this invention, the sufficiency and efficiency of lubrication inside the crankcase are improved.

[0023] 3. Because the first and second lubrication circuits of this invention can be independently controlled for lubrication, and the flow rate is controllable, combined with four fixed-point lubrication points on the engine, this lubrication system features low consumption and high efficiency, effectively reducing the amount of lubricating oil required and the size of the lubrication system. This lubrication system has a simple structure and is easy to operate; furthermore, the connecting oil pipes can be bent to conform to the engine's shape, saving space. Attached Figure Description

[0024] Figure 1 This is a block diagram of the overall structure of the lubrication system of the present invention;

[0025] Figure 2 Diagram showing the location of the lubricating oil holes in the air pump assembly;

[0026] Figure 3 This is a diagram showing the location of the lubricating oil hole in the first cylinder.

[0027] Figure 4 This is a diagram showing the location of the oil holes in the crankcase.

[0028] Explanation of reference numerals in the attached drawings: 1. Oil tank; 2. Electronic control unit; 3. First electronic oil pump; 4. Second electronic oil pump; 5. First oil check valve; 6. First three-way valve; 7. Oil port of the first cylinder; 8. Oil port of the second cylinder; 9. Second oil check valve; 10. Second three-way valve; 11. Oil port of the air pump assembly; 12. Oil port of the crankcase. Detailed Implementation

[0029] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0030] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0031] This embodiment provides an independent lubrication system for an aircraft piston engine, suitable for a two-stroke direct injection piston engine. It is a low-consumption, high-efficiency independent lubrication system that can provide lubricating oil to four lubrication holes on the engine in a fixed and controllable manner. It can effectively reduce the amount of lubricating oil carried by the engine, reduce the weight and volume of the lubrication system, and at the same time, the fixed and controllable lubrication method improves the sufficiency and efficiency of lubrication inside the cylinder block and crankcase.

[0032] See Figure 1-4 This embodiment of an independent lubrication system for an aircraft piston engine includes an oil tank 1, a first lubrication oil passage, a second lubrication oil passage, and an electronic control unit 2. The oil tank 1 serves as a storage tank for lubricating oil, providing lubricating oil to both lubrication oil passages.

[0033] See Figure 1The first lubrication circuit includes a first electronic oil pump 3, a first oil check valve 5, a first three-way valve 6, and connecting oil pipes. The inlet of the first electronic oil pump 3 is connected to the oil tank 1 via an oil pipe, and the outlet of the first electronic oil pump 3 is connected to the inlet of the first oil check valve 5 via an oil pipe. The first electronic oil pump 3 pressurizes and pumps the lubricating oil from the oil tank 1 into the first lubrication circuit. The outlet of the first oil check valve 5 is connected to the inlet of the first three-way valve 6 via an oil pipe, and the first oil check valve 5 is used to prevent backflow of lubricating oil in its circuit. The first three-way valve 6 has two outlets: one outlet is connected to the lubricating oil port 7 of the first cylinder via an oil pipe, and the other outlet is connected to the lubricating oil port 8 of the second cylinder via an oil pipe. By diverting the flow through the first three-way valve 6, the first lubricating oil circuit is divided into two fixed-point lubrication branches, one of which supplies oil to the first cylinder and the other to the second cylinder, thereby achieving lubrication of the first and second cylinders.

[0034] See Figure 1 The second lubrication circuit includes a second electronic oil pump 4, a second oil check valve 9, and a second three-way valve 10. The inlet of the second electronic oil pump 4 is connected to the oil tank 1 via an oil pipe, and the outlet of the second electronic oil pump 4 is connected to the inlet of the second oil check valve 9 via an oil pipe. The second electronic oil pump 4 pressurizes and pumps the lubricating oil from the oil tank 1 into the second lubrication circuit. The outlet of the second oil check valve 9 is connected to the inlet of the second three-way valve 10 via an oil pipe, and the second oil check valve 9 is used to prevent backflow of lubricating oil in its circuit. The second three-way valve 10 has two outlets. One outlet of the second three-way valve 10 is connected to the lubricating oil hole 11 of the air pump assembly via an oil pipe, used for lubricating the bearings inside the air pump assembly. The other outlet of the second three-way valve 10 is connected to the lubricating oil hole 12 of the crankcase via an oil pipe, used for lubricating the inside of the crankcase. The second lubricating oil circuit is divided into two lubrication branches by the second three-way valve 10. One branch supplies oil to the lubricating oil hole 11 of the air pump assembly, and the other branch supplies oil to the lubricating oil hole 12 of the crankcase.

[0035] See Figure 1 The electronic control unit 2 is electrically connected to the first electronic lubricating oil pump 3 and the second electronic lubricating oil pump 4, respectively, and is used to control the operating frequency of the two electronic lubricating oil pumps, thereby precisely adjusting the different lubricating oil volume requirements of the first and second lubricating oil circuits. The electronic control unit 2 can independently control the first and second lubricating oil circuits, allowing either the first or second lubricating oil circuit to operate independently as needed, and can control the lubricating oil volume of each lubricating oil circuit separately, thereby reducing oil injection consumption and improving lubrication efficiency.

[0036] See Figure 3The oil lubrication hole 7 of the first cylinder and the oil lubrication hole 8 of the second cylinder are respectively located on the cylinder heads of the first and second cylinders. The first and second cylinders of the two-stroke direct injection piston engine are symmetrically arranged. Figure 3 Only the location of the oil hole 7 on the first cylinder is shown. Considering that when the piston moves within the cylinder, the combustible gas mixed with gasoline is compressed to near top dead center and ignited, resulting in gas detonation and consuming a large amount of lubricating oil, this invention places the oil holes of both cylinders on the cylinder head to conserve lubricating oil. Simultaneously, the electronic control unit 2 controls the first electronic oil pump 3 to operate independently, thereby achieving independent lubrication of the two cylinder lubrication points.

[0037] See Figure 2 The oil lubrication hole 11 of the air pump assembly is located on the housing of the air pump assembly, at the outer housing corresponding to the eccentric gear mounting position inside the air pump assembly, so that lubricating oil can flow to the bearing mounting position of the air pump assembly. During engine operation, the eccentric gear and bearing in the air pump assembly rotate at high speed, and lubricating oil is sprayed at this point, which can drive the lubricating oil into various positions of the crankcase, greatly improving the uniformity and efficiency of crankcase lubrication.

[0038] See Figure 4 The oil hole 12 of the crankcase is located at the upper end of the crankcase of the engine. The oil is directly injected into the inside of the crankcase and is driven to various parts of the crankcase by the movement of the internal components.

[0039] The lubricating oil entering the air pump assembly lubricating hole 11 and the crankcase lubricating hole 12 is supplied by the same electronic lubricating pump (second electronic lubricating pump 4), and both lubricate simultaneously. The second electronic lubricating pump 4 can be controlled to operate independently by the electronic control unit 2, and its flow rate can be adjusted according to the lubricating oil demand.

[0040] See Figure 1 When using this lubrication system, the lubricating oil that needs to flow into the first and second cylinders flows from the oil tank 1 to the first electronic oil pump 3, then through the first oil check valve 5, and then through the first three-way valve 6. The oil is then split into two paths at the two outlets of the first three-way valve 6, flowing into the oil holes 7 of the first cylinder and 8 of the second cylinder respectively, thus lubricating the two cylinder bodies. The lubricating oil that needs to flow into the air pump assembly and crankcase flows from the oil tank 1 to the second electronic oil pump 4, then through the second oil check valve 9, and then through the second three-way valve 10. The oil is then split into two paths at the two outlets of the second three-way valve 10, flowing into the oil holes 11 of the air pump assembly and 12 of the crankcase respectively.

[0041] The lubrication system of this invention is located outside the engine. All connecting oil pipes in both the first and second lubrication circuits are arranged outside the engine, with each pipe length determined by requirements and allowing for arbitrary bending. Specifically, in the first lubrication circuit, the oil pipes connecting the oil tank 1 and the first electronic oil pump 3, the first electronic oil pump 3 and the first oil check valve 5, the first oil check valve 5 and the first three-way valve 6, and the first three-way valve 6 and the two cylinder blocks are all located outside the engine, and each pipe segment can be bent arbitrarily. Similarly, in the second lubrication circuit, the oil pipes connecting the oil tank 1 and the second electronic oil pump 4, the second electronic oil pump 4 and the second oil check valve 9, the second oil check valve 9 and the second three-way valve 10, the oil port 11 connecting the second three-way valve 10 and the air pump assembly, and the oil port 12 connecting the second three-way valve 10 and the crankcase are all located outside the engine, and each pipe segment can be bent arbitrarily. This allows the two lubrication circuits to conform to the engine's shape, saving installation space.

[0042] Because this lubrication system has two oil pumps, and each pump is controlled independently by an ECU (Electronic Control Unit), the flow rate of either pump can be increased individually if it is necessary to increase the oil volume in two cylinders or the crankcase. Therefore, compared with traditional aircraft engine lubrication systems, this system reduces oil consumption and improves oil utilization during the lubrication process.

[0043] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. An independent lubrication system for an aircraft piston engine, characterized in that, It includes an oil tank, a first lubrication circuit, a second lubrication circuit, and an electronic control unit; The oil tank provides lubricating oil to two lubrication lines; The first lubrication circuit is used to supply lubricating oil to the two cylinders of the engine. The first lubrication circuit includes a first electronic lubricating oil pump, which is used to supply lubricating oil in the lubricating oil tank to the first lubrication circuit. The second lubrication circuit is used to supply lubricating oil to the engine's air pump assembly and crankcase. The second lubrication circuit includes a second electronic oil pump, which supplies lubricating oil from the oil tank to the second lubrication circuit. The electronic control unit is electrically connected to each of the two electronic lubricating oil pumps and is used to control the operating frequency of the two electronic lubricating oil pumps to control the flow rate.

2. The independent lubrication system for an aircraft piston engine according to claim 1, characterized in that, The first lubrication circuit also includes a first oil check valve and a first three-way valve; the inlet of the first electronic lubricating pump is connected to the lubricating oil tank through an oil pipe, and the outlet of the first electronic lubricating pump is connected to the inlet of the first oil check valve through an oil pipe; the outlet of the first oil check valve is connected to the inlet of the first three-way valve through an oil pipe, and the first oil check valve is used to prevent the lubricating oil in its oil circuit from flowing back; one outlet of the first three-way valve is connected to the lubricating oil hole of the first cylinder through an oil pipe, and the other outlet of the first three-way valve is connected to the lubricating oil hole of the second cylinder through an oil pipe, respectively for lubricating the first cylinder and the second cylinder.

3. The independent lubrication system for an aircraft piston engine according to claim 1, characterized in that, The second lubrication circuit also includes a second oil check valve and a second three-way valve; the inlet of the second electronic lubricating pump is connected to the lubricating oil tank through an oil pipe, and the outlet of the second electronic lubricating pump is connected to the inlet of the second oil check valve through an oil pipe; the outlet of the second oil check valve is connected to the inlet of the second three-way valve through an oil pipe, and the second oil check valve is used to prevent the lubricating oil in its oil circuit from flowing back; one outlet of the second three-way valve is connected to the lubricating oil hole of the air pump assembly through an oil pipe, and is used to lubricate the bearings inside the air pump assembly; the other outlet of the second three-way valve is connected to the lubricating oil hole of the crankcase through an oil pipe, and is used to lubricate the inside of the crankcase.

4. The independent lubrication system for an aircraft piston engine according to claim 2, characterized in that, The oil lubrication holes of the first cylinder and the second cylinder are respectively located on the cylinder heads of the first cylinder and the second cylinder.

5. The independent lubrication system for an aircraft piston engine according to claim 1, characterized in that, The lubricating oil hole of the air pump assembly is located on the outer housing of the air pump assembly, at the location on the outer housing corresponding to the eccentric gear mounting position inside the air pump assembly.

6. The independent lubrication system for an aircraft piston engine according to claim 1, characterized in that, The oil hole of the crankcase is located at the upper end of the crankcase of the engine.

7. The independent lubrication system for an aircraft piston engine according to claim 1, characterized in that, The connecting oil pipes in the first and second lubrication circuits are all located outside the engine and can be bent arbitrarily.

8. The independent lubrication system for an aircraft piston engine according to claim 1, characterized in that, The independent lubrication system is applied to a two-stroke direct injection piston engine.

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