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 load any more, and the bearing capacity of the output end of the crankshaft is greatly improved. In addition, the 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 utility model relates to the technical field of aviation engines, in particular to a piston aviation engine. Background Art

[0002] Refer to the attached Figure 1 In existing piston aircraft engines, the main body of the crankshaft 2 is installed in the casing 1, with both ends of the crankshaft 2 extending outside the casing 1. One end of the crankshaft (output end 21) is connected to the propeller, and the other end (connection end 22) is connected to the magneto 6, starting gear 5, and other components. Depending on the needs of use, some aircraft engines also require speed reduction to increase torque. In this case, a reduction gearbox is installed at the output end of the crankshaft, and the propeller is installed on the output shaft of the reduction gearbox. Such aircraft engines have the following problems:

[0003] 1. Installing a reduction gearbox will increase the overall 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 components such as the magneto and starting gear 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 will damage the aircraft engine when overloaded. Utility Model Content

[0006] In order to overcome the deficiencies in 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 starting gear are placed at the output end of the crankshaft to reduce the rotational 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 gearbox, wherein the reduction gearbox 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 gearbox comprises a casing consisting of a front casing, a middle casing, and a rear casing, the rear casing being mounted on the casing, and the output end of the crankshaft extending into the rear casing; a magnetic motor and a starting gear disc are mounted in the space formed by the rear casing and the middle casing, and 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 being connected to the output end of the crankshaft via a coupling, and a clutch being provided 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 washer are installed, and the large gear is loosely sleeved 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 that cooperates with the starting gear disc is installed on the middle box.

[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 rotational 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 load-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] Attachment Figure 1 Shown is a schematic structural diagram of a conventional aircraft engine casing and crankshaft.

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

[0025] Attachment Figure 3 Shown is a schematic diagram of the main structure of the aircraft engine.

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

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

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

[0029] In the accompanying drawings: 1. Casing; 11. Rubber plug; 2. Crankshaft; 21. Output end; 22. Connecting end; 3. Housing; 31. Rear housing; 32. Middle housing; 321. Starting motor mounting hole; 322. Window opening; 33. Front housing; 4. Coupling; 5. Starting gear plate; 6. Magneto; 61. Magnetic steel rotor; 62. Magnetic electrode; 7. Input gear shaft; 71. Input shaft; 72. Pinion; 73. Bearing; 8. Output gear shaft; 81. Output shaft; 82. Gear; 83. Washer; 84. Bearing; 85. Retaining ring; 86. Oil seal; 9. Clutch; 91. Tooth groove; 92. Thread nest; 93. Disc spring. DETAILED DESCRIPTION

[0030] The following describes preferred embodiments of the present invention with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely intended to illustrate 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, terms such as "front," "rear," "up," "down," "left," "right," "vertical," "horizontal," "inside," and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or component must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can mean fixed, detachable, or integral; mechanical or electrical; direct, indirect through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0031] Refer to the 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, and the two ends of the casing 1 have a stopper and a bearing hole. Unlike existing piston-type horizontally opposed four-cylinder aircraft engines, the crankshaft 2 has only one output end 21, which 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] Refer to the attached Figure 3 and attached Figure 4 The reduction gearbox is mounted on the stopper at the left end of the casing 1. The reduction gearbox comprises a housing 3 comprising a front housing 33, a middle housing 32, and a rear housing 31. The rear housing 31 has multiple connection holes and is bolted to the casing 1. A through hole is provided in the middle of the rear housing 31, which mates with the stopper. After the rear housing 31 is connected to the casing 1, the crankshaft output end 21 extends through the through hole into the rear housing 31.

[0033] The right end of the middle case 32 is provided with a plurality of connection holes, and the left end of the rear case 31 is provided with a plurality of threaded holes corresponding to the connection holes. 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 starting gear wheel 5 are installed in the space formed by the rear case 31 and the middle case 32. Figure 1 The connection structure shortens the total length of the aircraft engine and does not require consideration of the dynamic sealing problem between the left end of the crankshaft and the casing 1.

[0034] Specifically, the magnetic motor 6 primarily consists of a magnetic steel rotor 61 and two magnetic poles 62. The two magnetic poles 62 are symmetrically mounted on the rear housing 31. The magnetic steel rotor 61 is mounted on the output end 21 of the crankshaft. The starting gear 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) is mounted in the starting motor mounting hole 321. When the aircraft engine is started, the gear at the head end of the starting motor engages with the starting gear 5, driving the crankshaft to rotate. The space formed by the rear housing 31 and the middle housing 32 is an unsealed space. A window opening 322 is provided in the middle housing 32, through which the installation status and rotation angle of the magnetic steel rotor 61 can be observed.

[0035] The right end of the front housing 33 is provided with a plurality of connection holes, and the left end of the middle housing 32 is provided with a plurality of threaded holes corresponding to the connection holes. The front housing 33 is connected to the middle housing 32 by bolts. The reduction transmission mechanism consisting of the input gear shaft 7 and the 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 via the coupling 4, and the output gear shaft 8 is provided with a clutch 9.

[0036] Refer to the attached Figure 5 . Specifically, the input gear shaft 7 includes an input shaft 71, which 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 small gear 72 and a pair of bearings 73 are installed on the input shaft 71, and the small gear 72 is integrally connected to the input shaft 71 or connected by 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 to 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 mounted on the output shaft 81, and the large gear 82 is meshed with the small gear 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, it realizes the connection between the reduction transmission mechanism and the crankshaft, transmits power to the output shaft 81, and improves the output torque of the aircraft engine; second, it changes the support structure of the crankshaft output end 21, and changes the cantilever support structure of the crankshaft output end 21 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 magnetic motor 6 and the starting gear disc 5; third, the coupling 4 has a coaxiality tolerance, which plays a protective role in 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 provided on the output shaft 81. When the load torque is greater than the aircraft engine output torque, the clutch begins to slip.

[0039] Refer to the attached Figure 6 Specifically, the clutch 9 includes four tooth grooves 91 arranged on the end face of the large gear 82 and evenly distributed along the circumferential direction, as well as multiple 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 mounted on the output shaft 81 and is slidably connected to the output shaft 81 via 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 mounted 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, causing the tooth nest 92 to interlock with the tooth groove 91.

[0040] Four teeth, evenly spaced along the circumference of the tooth insert 92, mate with the tooth grooves. Because both the teeth and the tooth grooves 91 have curved surfaces, an inclined sliding surface is formed between the teeth and the tooth grooves 91 when engaged. During operation, the crankshaft 2 rotates the input shaft 71 through the coupling 4, while the pinion 72 drives the gear 82. Because the number of teeth on the pinion 72 is smaller than that on the gear 82, the aircraft engine can achieve increased deceleration and higher output torque.

[0041] When the load torque is less than the output torque of the aircraft engine, the teeth and tooth grooves 91 interlock 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 backward and causing the disc spring 93 to retract. At this time, the tooth nest 92 begins to slip, protecting the aircraft engine. When the load torque is again less than the output torque of the aircraft engine, the teeth and tooth groove 91 re-engage under the action of the disc spring 93. Because the present invention sets the tooth groove 91 on the end face of the large gear 82 and uses a disc spring 93 with a small volume and high thrust, it not only reduces the size and number of parts of the reduction gearbox, but also improves the compactness of the reduction gearbox, 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 sequence. 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] Parts not described in detail are prior art. Although the embodiments of the present invention have been shown and described, it will be 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 scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A piston aircraft engine comprising a casing and a reduction gearbox, wherein the reduction gearbox is mounted at one end of the casing and a crankshaft is mounted within the casing, wherein: The other end of the casing is closed, and the crankshaft has only one output end; the reduction gear box has a casing consisting 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 consisting 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 provided on the output gear shaft.

2. A piston aircraft engine according to claim 1, characterized in that: 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 washer are installed, and the large gear is loosely sleeved on the output shaft.

3. A piston aircraft engine according to 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, as well as 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.

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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