Overload protection structure of aero-engine speed reducer

Abstract

According to the overload protection structure of the aircraft engine speed reducer, the speed reducer comprises a box body, an input shaft and an output shaft are arranged in the box body, a small gear is arranged on the input shaft, a large gear is movably arranged on the output shaft in a sleeving mode, the large gear is connected with the small gear in a meshed mode, and a plurality of tooth grooves are evenly distributed in the end face of the large gear in the circumferential direction; a plurality of disc springs and a jaw sliding sleeve are mounted on the output shaft, and the jaw sliding sleeve is in sliding connection with the output shaft through a spline; a plurality of teeth matched with the tooth grooves are evenly distributed at the end of the tooth embedding sliding sleeve in the circumferential direction, and under pushing of the disc spring, the teeth and the tooth grooves are embedded in a staggered mode. When overload occurs, the jaw sliding sleeve overcomes the thrust of the disc spring and retracts backwards, and the jaw sliding sleeve starts to slip. The overload protection device has the overload protection effect, when the load exceeds the safety range, the speed reducer can automatically slip, and the protection effect on the aero-engine is achieved. The size and the number of parts of the reduction gearbox are reduced, and the compactness of the reduction gearbox is improved.

Description

Technical Field

[0001] The invention relates to the technical field of aeroengines, and in particular to an overload protection structure of an aeroengine reducer. Background Art

[0002] According to the use requirements, some aircraft engines need to increase the output torque by reducing speed. In this case, a reduction box should be installed at the output end of the crankshaft, and the propeller should be installed on the output shaft of the reduction box. The current problem is that when the load is overloaded, it will cause damage to the aircraft engine, so an overload protection structure needs to be set in the reduction box. Summary of the invention

[0003] In order to overcome the deficiencies in the background technology, the present invention discloses an overload protection structure for an aircraft engine reducer, the purpose of which is to prevent the reducer from slipping when overloaded, thereby protecting the aircraft engine.

[0004] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0005] An overload protection structure for an aircraft engine reducer, the reducer comprises a housing, an input shaft and an output shaft are arranged in the housing, a small gear is arranged on the input shaft, a large gear is loosely sleeved on the output shaft, the large gear is meshed and connected with the small gear, and a plurality of tooth grooves are evenly distributed along the circumferential direction on the end face of the large gear; a plurality of disc springs and a toothed sleeve are installed on the output shaft, the toothed sleeve is slidably connected with the output shaft through a spline; a plurality of teeth matching the tooth grooves are evenly distributed along the circumferential direction at the end of the toothed sleeve, and the teeth are staggered and engaged with the tooth grooves under the push of the disc spring; when overload occurs, the toothed sleeve retreats backwards to overcome the thrust of the disc spring, and the toothed sleeve begins to slip.

[0006] To further improve the technical solution, bearings are installed at both ends of the input shaft and the output shaft, and the housing is composed of a front housing and a rear housing, and bearing mounting holes corresponding to the input shaft and the output shaft are arranged in the front housing and the rear housing.

[0007] To further improve the technical solution, an inner ring groove is provided in the bearing mounting hole located at the output end of the output shaft, and a hole retaining ring is installed in the inner ring groove, and the hole retaining ring is used to limit the axial movement of the bearing.

[0008] To further improve the technical solution, an oil seal is installed in the bearing mounting hole located at the output end of the output shaft.

[0009] To further improve the technical solution, a hub is provided at the output end of the output shaft, and the hub is used to connect the propeller; an external spline is provided in the middle part of the output shaft, and an internal spline matching the external spline is provided in the hole of the toothed sleeve.

[0010] To further improve the technical solution, a plurality of washers are installed on the output shaft, and the washers are used to adjust the thrust of the disc spring.

[0011] To further improve the technical solution, a stepped shaft is provided at one end of the output shaft, an outer ring groove is provided at the other end of the output shaft, a pair of semicircular baffles are installed in the outer ring groove, and the stepped shaft and the semicircular baffles are used to bear the thrust from the disc spring; a locking ring with an outer flange is also installed on the output shaft, and a pair of semicircular baffles are located inside the outer flange of the locking ring.

[0012] After implementing the above technical solution, compared with the background technology, the beneficial effects produced by the present invention are:

[0013] The reduction gearbox of the present invention has not only a deceleration function, but also an overload protection function. When the load exceeds a safe range, the reducer will automatically slip, thereby protecting the aircraft engine.

[0014] The present invention arranges the tooth groove on the end face of the large gear and adopts a disc spring with small volume and large thrust, which not only reduces the volume and the number of parts of the reduction box, but also improves the compactness of the reduction box. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Attached Figure 1 Shown is an appearance diagram of an aircraft engine reducer.

[0016] Attached Figure 2 The attached Figure 1 Schematic diagram of the cross-sectional structure.

[0017] Attached Figure 3 The attached Figure 1 Exploded diagram.

[0018] Attached Figure 4 Shown is a schematic diagram of the structure of the output shaft, disc spring, toothed sleeve and large gear.

[0019] In the attached drawings: 1. housing; 11. front housing; 12. rear housing; 2. input shaft; 3. pinion; 4. output shaft; 41. propeller hub; 42. external spline; 43. stepped shaft; 5. large gear; 51. tooth groove; 6. toothed sleeve; 61. teeth; 7. disc spring; 8. bearing; 91. retaining ring for hole; 92. oil seal; 93. gasket; 94. semicircular retaining plate; 95. locking ring. DETAILED DESCRIPTION

[0020] 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.

[0021] Attached Figure 1 The figure shows the appearance of an aircraft engine reducer. Figure 1 It can be seen that the reducer includes a housing 1 , which is composed of a front housing 11 and a rear housing 12 , and an input shaft 2 and an output shaft 4 are arranged inside the housing 1 .

[0022] Attached Figure 2 The attached Figure 1 Schematic diagram of the cross-section structure, attached Figure 3 The attached Figure 1 Exploded diagram of Figure 4 The structure diagram of the output shaft 4, the disc spring 7, the toothed sleeve 6 and the large gear 5 is shown. Figure 2 , Attachment Figure 3 and attached Figure 4 It can be seen that a pinion 3 is machined on the input shaft 2, and bearings 8 are installed at both ends of the pinion 3. The pinion and the input shaft can be machined as a whole, or the pinion can be fixed to the input shaft by a key connection.

[0023] A hub 41 is provided at the output end of the output shaft 4, and an external spline 42 is provided at the middle portion of the output shaft 4. The hub 41 has a stop and a connection hole for connecting a propeller. A large gear 5 is installed on the output shaft 4, but the large gear 5 is loosely sleeved on the output shaft 4, and the large gear 5 cannot directly drive the output shaft 4 to rotate when it rotates. The large gear 5 is meshed with the small gear 3, and the large gear 5 is driven to rotate when the input shaft 2 rotates. On the left end face of the large gear 5, four tooth grooves 51 are evenly distributed along the circumferential direction, and the tooth grooves 51 have a concave arc surface.

[0024] A tooth sleeve 6 is also installed on the output shaft 4, and the tooth sleeve 6 is located on the left side of the large gear 5. An internal spline is provided in the hole of the tooth sleeve 6, and the internal spline is matched and connected with the external spline 42 on the output shaft 4. In other words, the tooth sleeve 6 can slide on the output shaft 4 and can drive the output shaft 4 to rotate. Four teeth 61 matching with the tooth groove 51 are evenly distributed along the circumferential direction at the right end of the tooth sleeve 6, and the teeth 61 have a protruding arc surface.

[0025] A plurality of disc springs 7 are also mounted on the output shaft 4, and the disc springs 7 are arranged on the left side of the toothed sleeve 6. The function of the disc springs 7 is to provide an axial thrust for the toothed sleeve 6, so that the teeth 61 are staggered and engaged with the tooth grooves 51 on the large gear 5. The disc springs 7 have the advantages of small size and large thrust.

[0026] A stepped shaft 43 is provided at the output end of the output shaft 4. A bearing 8 and two washers 93 are installed between the stepped shaft 43 and the disc spring 7. The thrust of the disc spring 7 can be adjusted by changing the thickness of the washers 93. An outer ring groove is provided at the other end of the output shaft 4. A pair of semicircular baffles 94 are installed in the outer ring groove. A locking collar 95 with an outer flange is installed between the pair of semicircular baffles 94 and the large gear 5. The pair of semicircular baffles 94 are located in the outer flange of the locking collar 95. The function of the outer flange is to prevent the semicircular baffles 94 from escaping from the outer ring groove. The function of the stepped shaft 43 and the semicircular baffles 94 is to bear the thrust from the disc spring 7, to prevent the thrust from acting on the housing 1 through the bearing 8, and to make the output shaft 4 bear unnecessary axial force.

[0027] Bearing mounting holes corresponding to the bearings 8 at both ends of the input shaft 2 and the output shaft 4 are provided in the front housing 11 and the rear housing 12. An inner ring groove is provided in the bearing mounting hole at the output end of the output shaft 4. A hole retaining ring 91 is installed in the inner ring groove. The hole retaining ring 91 is used to limit the axial movement of the bearing.

[0028] The reduction box needs to be added with a certain amount of lubricating oil, and a refueling port and an oil drain port are provided on the front box body 11. In order to seal, an oil seal 92 is installed at the output end of the output shaft 4 and the input end of the input shaft 2.

[0029] Again, refer to the attached Figure 2 and attached Figure 4 . During operation, the crankshaft of the aircraft engine drives the input shaft 2 to rotate through the coupling, and the large gear 5 rotates following the small gear 3. Since both the teeth 61 and the tooth grooves 51 have arc-shaped surfaces, an inclined sliding surface is formed between the teeth 61 and the tooth grooves 51 when they are engaged. When the load torque is less than the output torque of the aircraft engine, the teeth 61 and the tooth grooves 51 are staggered and engaged with each other under the action of the disc spring 7, and no relative sliding occurs. At this time, the tooth sleeve 6 drives the output shaft 4 to rotate. Since the number of teeth of the pinion 3 is less than the number of teeth of the large gear 5, the aircraft engine can increase the deceleration and increase the output torque.

[0030] When the load torque is greater than the output torque of the aircraft engine, under the action of the inclined sliding surface, the teeth 61 begin to slide relative to the tooth groove 51, pushing the tooth sleeve 6 to move backward and causing the disc spring 7 to retract. At this time, the tooth sleeve 6 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 61 re-engage with the tooth groove 51 under the action of the disc spring 7.

[0031] As can be seen from the above, the present invention sets the tooth groove 51 on the end face of the large gear 5 and adopts the disc spring 7 with small volume and large thrust, which not only reduces the volume and number of parts of the reduction box, but also improves the compactness of the reduction box. More importantly, when the load exceeds the safety range, the reducer will automatically slip, which plays a role in protecting the aircraft engine.

[0032] 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. An overload protection structure of an aircraft engine reducer, the reducer comprising a housing, an input shaft and an output shaft being arranged in the housing, wherein: A small gear is provided on the input shaft, and a large gear is loosely sleeved on the output shaft. The large gear is meshed with the small gear, and a plurality of tooth grooves are evenly distributed circumferentially on the end face of the large gear. A plurality of disc springs and a toothed sleeve are installed on the output shaft, and the toothed sleeve is slidably connected to the output shaft through a spline. A plurality of teeth matching the tooth grooves are evenly distributed circumferentially on the end of the toothed sleeve, and the teeth are staggered and engaged with the tooth grooves under the push of the disc spring. When overload occurs, the toothed sleeve retreats backwards to overcome the thrust of the disc spring, and the toothed sleeve begins to slip.

2. The overload protection structure of an aircraft engine reducer according to claim 1, characterized in that: Bearings are installed at both ends of the input shaft and the output shaft. The housing consists of a front housing and a rear housing. The front housing and the rear housing are provided with bearing installation holes corresponding to the input shaft and the output shaft.

3. The overload protection structure of an aircraft engine reducer as claimed in claim 2, characterized in that: An inner ring groove is arranged in the bearing mounting hole at the output end of the output shaft, and a hole retaining ring is installed in the inner ring groove. The hole retaining ring is used to limit the axial movement of the bearing.

4. The overload protection structure of an aircraft engine reducer according to claim 2, characterized in that: An oil seal is installed in the bearing mounting hole located at the output end of the output shaft.

5. The overload protection structure of an aircraft engine reducer according to claim 1, characterized in that: A propeller hub is arranged at the output end of the output shaft, and the propeller hub is used to connect the propeller; an external spline is arranged in the middle part of the output shaft, and an internal spline matching the external spline is arranged in the hole of the tooth-embedded sliding sleeve.

6. The overload protection structure of an aircraft engine reducer according to claim 1, characterized in that: A plurality of washers are also installed on the output shaft, and the washers are used to adjust the thrust of the disc spring.

7. The overload protection structure of an aircraft engine reducer according to claim 1, characterized in that: A stepped shaft is provided at one end of the output shaft, an outer ring groove is provided at the other end of the output shaft, a pair of semicircular baffles are installed in the outer ring groove, and the stepped shaft and the semicircular baffles are used to bear the thrust from the disc spring; a locking ring with an outer flange is also installed on the output shaft, and a pair of semicircular baffles are located inside the outer flange of the locking ring.

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