Piston type aero-engine

Abstract

A piston type aero-engine comprises a cartridge receiver and a reduction gearbox, the reduction gearbox is installed at one end of the cartridge receiver, a crankshaft is installed in the cartridge receiver, the other end of the cartridge receiver is closed, and the crankshaft is only provided with one output end. The reduction gearbox is provided with a box body consisting of a front box body, a middle box body and a rear box body, the rear box body is mounted on the casing, and the output end of the crankshaft extends into the rear box body; a magneto and a starting fluted disc are installed in the space formed by the rear box body and the middle box body, a speed reduction transmission mechanism composed of an input gear shaft and an output gear shaft is installed in the space formed by the middle box body and the front box body, the input gear shaft is connected with the output end of the crankshaft through a coupler, and a clutch is arranged on the output gear shaft. The supporting structure of the crankshaft is changed, the right end of the crankshaft does not bear rotation loads any more, and the bearing capacity of the output end of the crankshaft is greatly improved. In addition, a clutch with a compact structure is arranged in the reduction gearbox, so that the aero-engine can be effectively prevented from being damaged due to overload.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengines, and in particular to a piston aeroengine. Background Art

[0002] See attached Figure 1 In the existing piston aircraft engine, the main body of the crankshaft 2 is installed in the casing 1, and the two ends of the crankshaft 2 extend out of the casing 1. One end (output end 21) of the crankshaft is connected to the propeller, and the other end (connection end 22) is connected to the magneto 6, the starting gear 5 and other components. According to the use requirements, some aircraft engines also need to increase the torque by reducing speed. At this time, a reduction box needs to be set at the output end of the crankshaft, and the propeller is installed on the output shaft of the reduction box. Such aircraft engines have the following problems:

[0003] 1. The installation of a reduction gearbox will increase the total length of the aircraft engine, which is not conducive to the miniaturization of the aircraft engine;

[0004] 2. The connection end and output end of the crankshaft are both cantilever support structures, and the rotational inertia of the magneto, starting gear and other components is large, which can easily cause fatigue and fracture of the crankshaft connection end;

[0005] 3. The reduction gearbox lacks an overload protection mechanism, which may damage the aircraft engine when overloaded. Summary of the invention

[0006] In order to overcome the shortcomings of the background technology, the present invention discloses a piston aircraft engine, the purpose of which is:

[0007] 1. Shorten the overall length of the aircraft engine;

[0008] 2. The magneto and the starting gear are arranged at the output end of the crankshaft to reduce the rotation load at the crankshaft connection end; the cantilever support structure at the crankshaft output end is changed to a two-end support structure through the reduction gearbox to improve the load-bearing capacity of the crankshaft output end;

[0009] 3. A clutch is installed in the reduction gearbox to prevent the aircraft engine from overloading.

[0010] Specifically, the present invention adopts the following technical solutions:

[0011] A piston aircraft engine comprises a casing and a reduction box, wherein the reduction box is mounted at one end of the casing, a crankshaft is mounted in the casing, the other end of the casing is closed, and the crankshaft has only one output end; the reduction box has a casing consisting of a front casing, a middle casing, and a rear casing, the rear casing is mounted on the casing, and the output end of the crankshaft extends into the rear casing; a magnetic motor and a starting gear plate are mounted in the space formed by the rear casing and the middle casing, a reduction transmission mechanism consisting of an input gear shaft and an output gear shaft is mounted in the space formed by the middle casing and the front casing, the input gear shaft is connected to the output end of the crankshaft through a coupling, and a clutch is arranged on the output gear shaft.

[0012] To further improve the technical solution, the input gear shaft includes an input shaft, on which a small gear and a bearing are installed, and the small gear is fixedly connected to the input shaft; the output gear shaft includes an output shaft, on which a large gear, a clutch, a bearing and a gasket are installed, and the large gear is loosely mounted on the output shaft.

[0013] To further improve the technical solution, the clutch includes a plurality of tooth grooves arranged on the end face of the large gear and evenly distributed along the circumferential direction, and also includes a disc spring and a tooth nest; the tooth nest is installed on the output shaft and is slidingly connected to the output shaft through a spline, and a plurality of teeth matching the tooth grooves are evenly distributed along the circumferential direction at the end of the tooth nest; the disc spring is installed on the output shaft and is used to apply thrust to the tooth nest so that the teeth and the tooth grooves are staggered and engaged.

[0014] To further improve the technical solution, the coupling is an elastic coupling.

[0015] To further improve the technical solution, a starting motor cooperating with a starting gear disc is installed on the middle box body.

[0016] To further improve the technical solution, the magnetic motor is mainly composed of a magnetic steel rotor and magnetic electrodes, the magnetic electrodes are installed on the rear box body, and the magnetic steel rotor is installed on the output end of the crankshaft.

[0017] To further improve the technical solution, the other end of the receiver is closed by a rubber plug.

[0018] After implementing the above technical solution, compared with the background technology, the beneficial effects produced by the present invention are:

[0019] 1. The right end of the casing is closed, and the right end of the crankshaft no longer bears the rotation load;

[0020] 2. The overall length of the aircraft engine has been shortened, which is conducive to the miniaturization of the aircraft engine;

[0021] 3. The support structure of the crankshaft output end has been changed from the original cantilever support structure to a two-end support structure, which greatly improves the bearing capacity of the crankshaft output end and is less prone to fatigue and fracture;

[0022] 4. A compact clutch is installed in the reduction gearbox, which can effectively prevent the aircraft engine from being damaged due to overload. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attached Figure 1 Shown is a schematic structural diagram of a conventional aircraft engine casing and crankshaft.

[0024] Attached Figure 2 Shown is a schematic structural diagram of the aircraft engine casing and crankshaft.

[0025] Attached Figure 3 What is shown is the schematic diagram of the main structure of the aircraft engine.

[0026] Attached Figure 4 Shown is an exploded view of the reduction gearbox at an angle.

[0027] Attached Figure 5 Shown is an exploded view of the reduction gearbox at another angle.

[0028] Attached Figure 6 Shown is a schematic diagram of the structure of the large gear and the tooth nesting.

[0029] In the attached drawings: 1. casing; 11. rubber plug; 2. crankshaft; 21. output end; 22. connecting end; 3. casing; 31. rear casing; 32. middle casing; 321. mounting hole for starting motor; 322. window opening; 33. front casing; 4. coupling; 5. starting gear plate; 6. magnetic motor; 61. magnetic steel rotor; 62. magnetic electrode; 7. input gear shaft; 71. input shaft; 72. small gear; 73. bearing; 8. output gear shaft; 81. output shaft; 82. large gear; 83. gasket; 84. bearing; 85. retaining ring; 86. oil seal; 9. clutch; 91. tooth groove; 92. tooth nest; 93. disc spring. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. It should be noted that in the description of the present invention, the terms "front", "rear", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal connection of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0031] See attached Figure 2 A piston-type horizontally opposed four-cylinder aircraft engine includes a casing 1 and a crankshaft 2. The main body of the crankshaft 2 is installed in the casing 1. Both ends of the casing 1 have stoppers and bearing holes. Different from the existing piston-type horizontally opposed four-cylinder aircraft engines, the crankshaft 2 has only one output end 21, and the output end 21 of the crankshaft extends outward from the bearing hole at the left end of the casing 1. For sealing, the bearing hole at the right end of the casing 1 is blocked by a rubber plug 11.

[0032] See attached Figure 3 and attached Figure 4 The reduction box is mounted on the stopper at the left end of the casing 1. The reduction box has a casing 3 consisting of a front casing 33, a middle casing 32, and a rear casing 31. The rear casing 31 has a plurality of connection holes and is mounted on the casing 1 by bolts. A through hole matching the stopper is provided in the middle of the rear casing 31. After the rear casing 31 is connected to the casing 1, the output end 21 of the crankshaft extends into the rear casing 31 through the through hole.

[0033] A plurality of connection holes are provided at the right end of the middle case 32, and a plurality of threaded holes corresponding to the connection holes are provided at the left end of the rear case 31. The middle case 32 is connected to the rear case 31 by bolts. Since the crankshaft has only one output end 21, the magneto 6 and the starter gear 5 are installed in the space formed by the rear case 31 and the middle case 32. Figure 1 The connection structure shortens the overall length of the aircraft engine, and there is no need to consider the dynamic sealing problem between the left end of the crankshaft and the casing 1.

[0034] Specifically, the magnetic motor 6 is mainly composed of a magnetic steel rotor 61 and two magnetic electrodes 62. The two magnetic electrodes 62 are symmetrically mounted on the rear housing 31, and the magnetic steel rotor 61 is mounted on the output end 21 of the crankshaft. The starting gear plate 5 is coaxially mounted on the output end 21 of the crankshaft. A starting motor mounting hole 321 is provided on the middle housing 32. The starting motor (not shown in the figure) is mounted on the starting motor mounting hole 321. When the aircraft engine is started, the gear at the head end of the starting motor is meshed and connected with the starting gear plate 5 to drive the crankshaft to rotate. The space formed by the rear housing 31 and the middle housing 32 is a non-sealed space. A window opening 322 is provided in the middle housing 32, and the installation state and rotation angle of the magnetic steel rotor 61 can be observed through the window opening 322.

[0035] A plurality of connection holes are provided at the right end of the front housing 33, and a plurality of threaded holes corresponding to the connection holes are provided at the left end of the middle housing 32. The front housing 33 is connected to the middle housing 32 by bolts. A reduction transmission mechanism consisting of an input gear shaft 7 and an output gear shaft 8 is installed in the space formed by the middle housing 32 and the front housing 33. The input gear shaft 7 is connected to the output end 21 of the crankshaft through a coupling 4, and a clutch 9 is provided on the output gear shaft 8.

[0036] See attached Figure 5 . Specifically, the input gear shaft 7 includes an input shaft 71, and the input shaft 71 is coaxially connected to the output end 21 of the crankshaft through a coupling 4. In this embodiment, the coupling 4 is an elastic coupling. A pinion 72 and a pair of bearings 73 are installed on the input shaft 71, and the pinion 72 is connected to the input shaft 71 as a whole or through a key. The output gear shaft 8 includes an output shaft 81, and the front end of the output shaft 81 is provided with a connecting plate for connecting the propeller. A large gear 82, a pair of bearings 84, a retaining ring 85 and a plurality of washers 83 are installed on the output shaft 81, wherein the large gear 82 is loosely sleeved on the output shaft 81, and the large gear 82 is meshed and connected with the pinion 72. The space formed by the middle box body 32 and the front box body 33 is a sealed space, and oil seals 86 are provided at both ends of the input shaft 71 and the output shaft 81, and a certain amount of lubricating oil is injected into the sealed space through the oil filling port.

[0037] The input shaft 71 is connected to the output end 21 of the crankshaft through the coupling 4. First, the connection between the reduction transmission mechanism and the crankshaft is realized, and the power is transmitted to the output shaft 81, thereby improving the output torque of the aircraft engine; second, the support structure of the crankshaft output end 21 is changed, and the cantilever support structure of the crankshaft output end 21 is changed to a two-end support structure, which greatly improves the load-bearing capacity of the crankshaft output end 21 and can bear the rotational inertia of the magneto 6 and the starting gear 5; third, the coupling 4 has a coaxiality tolerance, which protects the connection between the input shaft 71 and the crankshaft output end 21.

[0038] In order to protect the aircraft engine from overload, a clutch is also provided on the output shaft 81. When the load torque is greater than the output torque of the aircraft engine, the clutch starts to slip.

[0039] Refer to the attached Figure 6 Specifically, the clutch 9 includes four tooth grooves 91 arranged on the end surface of the large gear 82 and evenly distributed in the circumferential direction, and also includes a plurality of disc springs 93 and a tooth nest 92. An external spline is provided in the middle portion of the output shaft 81, and an internal spline is provided in the tooth nest 92. The tooth nest 92 is installed on the output shaft 81 and is slidably connected to the output shaft 81 through the spline. In other words, the tooth nest 92 can slide on the output shaft 81 and can drive the output shaft 81 to rotate. The disc spring 93 is installed on the output shaft 81 and presses against one end of the tooth nest 92. The disc spring 93 is used to apply thrust to the tooth nest 92 so that the tooth nest 92 and the tooth groove 91 are staggered and interlocked.

[0040] Four teeth matching the tooth grooves are evenly distributed along the circumferential direction at the end of the tooth nest 92. Since both the teeth and the tooth groove 91 have arc surfaces, an inclined sliding surface is formed between the teeth and the tooth groove 91 when they are engaged. During operation, the crankshaft 2 drives the input shaft 71 to rotate through the coupling 4, and the pinion 72 drives the large gear 82 to rotate. Since the number of teeth of the pinion 72 is less than the number of teeth of the large gear 82, the aircraft engine can increase the deceleration and increase the output torque.

[0041] When the load torque is less than the output torque of the aircraft engine, the teeth and the tooth grooves 91 are staggered and interlocked under the action of the disc spring 93, and no relative sliding occurs. At this time, the tooth nest 92 drives the output shaft 81 to rotate. When the load torque is greater than the output torque of the aircraft engine, under the action of the inclined sliding surface, the teeth begin to slide relative to the tooth groove 91, pushing the tooth nest 92 to move backward and causing the disc spring 93 to retract. At this time, the tooth nest 92 begins to slip, which protects the aircraft engine. When the load torque is less than the output torque of the aircraft engine again, the teeth and the tooth groove 91 are re-engaged under the action of the disc spring 93. Since the present invention sets the tooth groove 91 on the end face of the large gear 82 and adopts a disc spring 93 with a small volume and large thrust, it not only reduces the volume and number of parts of the reduction box, but also improves the compactness of the reduction box, which is conducive to the miniaturization of the aircraft engine.

[0042] During assembly, first install the rear housing 31 on the casing 1, then install the two magnetic electrodes 62 symmetrically on the rear housing 31, and then install the magnetic steel rotor 61, the starting gear plate 5, and the coupling 4 on the output end 21 of the crankshaft in turn. Finally, insert the input shaft 71 into the coupling 4, and connect the reduction gear box body composed of the middle housing 32 and the front housing 33 to the rear housing 31 by bolts to form a complete reduction gear box integrating the magnetic motor 6, the starting gear plate 5, and the starting motor.

[0043] Although the embodiments of the present invention have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A piston aircraft engine, comprising a casing and a reduction box, wherein the reduction box is mounted at one end of the casing, and a crankshaft is mounted in the casing, wherein: The other end of the casing is closed, and the crankshaft has only one output end; the reduction box has a casing composed of a front casing, a middle casing, and a rear casing, the rear casing is installed on the casing, and the output end of the crankshaft extends into the rear casing; a magnetic motor and a starting gear plate are installed in the space formed by the rear casing and the middle casing, and a reduction transmission mechanism composed of an input gear shaft and an output gear shaft is installed in the space formed by the middle casing and the front casing, the input gear shaft is connected to the output end of the crankshaft through a coupling, and a clutch is arranged on the output gear shaft.

2. A piston aircraft engine according to claim 1, characterized in that: The input gear shaft comprises an input shaft, on which a small gear and a bearing are installed, and the small gear is fixedly connected to the input shaft; the output gear shaft comprises an output shaft, on which a large gear, a clutch, a bearing and a washer are installed, and the large gear is loosely sleeved on the output shaft.

3. A piston aircraft engine as claimed in claim 2, characterized in that: The clutch includes a plurality of tooth grooves arranged on the end face of the large gear and evenly distributed along the circumferential direction, and also includes a disc spring and a tooth nest; the tooth nest is installed on the output shaft and is slidingly connected to the output shaft through a spline, and a plurality of teeth matching the tooth grooves are evenly distributed along the circumferential direction at the end of the tooth nest; the disc spring is installed on the output shaft and is used to apply thrust to the tooth nest so that the teeth and the tooth grooves are staggered and embedded.

4. A piston aircraft engine according to claim 1, characterized in that: The coupling is an elastic coupling.

5. A piston aircraft engine according to claim 1, characterized in that: A starting motor matched with a starting gear disc is installed on the middle box body.

6. A piston aircraft engine according to claim 1, characterized in that: The magnetic motor is mainly composed of a magnetic steel rotor and magnetic electrodes. The magnetic electrodes are installed on the rear box body, and the magnetic steel rotor is installed on the output end of the crankshaft.

7. A piston aircraft engine according to claim 1, characterized in that: The other end of the receiver is closed by a rubber plug.

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