A star type multi-shaft gear transmission system for an aero-engine

Abstract

The application discloses a star type multi-shaft gear transmission system for an aero-engine, mainly comprising an input shaft, a gear transmission system, an output shaft and the like. The gear transmission system mainly comprises a split-flow transmission part and a parallel transmission part installed in an engine case, and a plurality of elastic load sharing shafts for connecting the split-flow transmission part and the parallel transmission part. Engine power is transmitted to a center spline shaft and a center wheel I of the gear transmission system through the input shaft, is split to a plurality of split-flow gear shafts meshed with the center wheel I, is transmitted to a plurality of parallel gear shafts through the elastic load sharing shafts which are constrained together in interference fit with the plurality of split-flow gear shafts, is parallel to a center wheel II meshed with the plurality of parallel gear shafts, and is finally transmitted to the output shaft to output power. The application is a star type gear transmission mechanism adopting the elastic load sharing shafts, realizes a transmission gear box with coaxial input and output shafts, small speed ratio, high speed and large power in a limited space size and weight range, and meets the requirements in the field of aero-engines.

Description

Technical Field

[0001] This invention relates to the field of aero-engine gear transmission technology, and specifically to a star-shaped multi-axis gear transmission system for aero-engines. Background Technology

[0002] In the field of aero-engines, there is a need to achieve low-ratio, high-speed, high-power transmission gearboxes with coaxial input and output shafts within limited space and weight. Existing coaxial input and output structures typically include two-stage parallel herringbone gear drives with the same center distance, or several planetary gear trains. Under the same space constraints, the two-stage parallel herringbone gear drive structure suffers from insufficient power per pair of herringbone teeth, and low motion and contact accuracy with multiple pairs of herringbone teeth in two stages. The several planetary gear train structure suffers from a large transmission ratio, making it difficult to meet design requirements. Summary of the Invention

[0003] The purpose of this invention is to provide a star-shaped multi-axis gear transmission system for aero engines, characterized in that it includes an input shaft, a gear transmission system, and an output shaft.

[0004] The input shaft and output shaft are respectively connected to the power input end and output end of the gear transmission system through an external spline structure.

[0005] The gear transmission system mainly includes a split transmission section and a parallel transmission section installed in the casing, as well as several elastic load-sharing shafts (the elastic load-sharing shafts utilize the elastic deformation and torsion of the metal material itself) for connecting the split transmission section and the parallel transmission section.

[0006] The split-drive section includes a central splined shaft I, a central wheel I, and a number of split-drive gear shafts equal to the number of elastic load-sharing shafts. The inner bores of the split-drive gear shafts I are interference-fitted with the outer diameters of the elastic load-sharing shafts. Gear teeth are machined onto the outer diameters of the split-drive gear shafts to form a gear structure. The central wheel I is mounted on the splined shaft I. The splined shaft I is the power input end of the gear transmission system. The central wheel I is a gear that meshes with the surrounding split-drive gear shafts. The gears are cylindrical herringbone gears.

[0007] The parallel drive system includes a central splined shaft II, a central wheel II, and a number of parallel gear shafts equal to the number of elastic load-sharing shafts. The outer circumference of each parallel gear shaft is machined with teeth to form a gear structure. Each of the parallel gear shafts is designed with an internal spline structure and engages with the elastic load-sharing shafts via splines. The central wheel II is mounted on the splined shaft II. The splined shaft II is the power output end of the gear transmission system. The central wheel II is a gear that meshes with the surrounding parallel gear shafts. The gears are cylindrical herringbone gears.

[0008] By changing the transmission ratio between the central gear I and the split gear shaft, and the transmission ratio between the central gear II and the parallel gear shaft, the gear transmission system can achieve speed increase or deceleration. During operation, power is first transmitted through the central spline shaft I to the central gear I, then to several split gear shafts meshing with the central gear I (i.e., "splitting"), and then transmitted through an elastic load-sharing shaft that is interference-fitted with the split gear shafts to several parallel gear shafts, finally to several parallel gear shafts.

[0009] On the central wheel II that meshes with the external gear shaft, that is, finally "parallel" to the central wheel II that meshes with several parallel gear shafts.

[0010] Furthermore, the casing also includes an intermediate bearing housing between the split-drive section and the parallel-drive section. The intermediate bearing housing is used to mount bearings that support the split-drive shaft and the parallel-drive shaft.

[0011] Furthermore, the gearbox casing is an overall cylindrical structure with open ends and a substantially hollow interior. The casing has a lubricating oil inlet, a lubricating oil return, a vent, and lubricating oil passages. The front opening of the casing is sealed with bearing housing I and an input end cap. The rear opening of the casing is sealed with bearing housing III and an output end cap.

[0012] Furthermore, the input end cap is fixed to the bearing housing I with screws. The connecting disc and bearing housing I are fixed to the gearbox casing with screws. The plurality of bearings are installed in the bearing holes on the bearing housing I. The bearing outer ring baffle I is fixed to the bearing housing I with screws. The plurality of oil injection pipes I are fixed to the bearing housing I with screws.

[0013] Furthermore, the output end cap is fixed to the bearing housing III with screws. The bearing housing III is fixed to the gearbox casing with screws. The plurality of bearings are installed in the bearing holes on the bearing housing III. The plurality of bearing outer ring baffles III are fixed to the bearing housing III with screws. The plurality of oil injection pipes II are fixed to the bearing housing III with screws.

[0014] The technical effectiveness of this invention is undeniable. The system is based on the theory of "first splitting, then merging," where the elastic load-sharing shaft, through its own torsional deformation, ensures that the transmission power on each splitting gear shaft and merging gear shaft is essentially the same after splitting and before merging, thus improving the consistency of transmission power on each drive shaft before and after splitting. Furthermore, the use of spline and other mating structures creates suitable floating in the axial and radial directions, improving the load-sharing capacity of the gearbox during the splitting and merging processes. Attached Figure Description

[0015] Figure 1This is a schematic diagram of the gearbox of the present invention;

[0016] Figure 2 This is a schematic cross-sectional view of the gearbox structure of the present invention;

[0017] Figure 3 This is a cross-sectional view of the input bearing housing and the shunt drive section of the present invention.

[0018] Figure 4 This is a cross-sectional view of the intermediate bearing housing portion of the present invention;

[0019] Figure 5 This is a cross-sectional view of the output bearing housing and parallel transmission part of the present invention.

[0020] Figure 1-5 In the middle: Input shaft (01), gear transmission system (02), output shaft (03), input end cover (0201), connecting plate (0203), elastic load-sharing shaft (0204), output end cover (0205), casing (0206), input end bearing housing (21), split transmission part (22), parallel transmission part (23), output end bearing housing (24), intermediate bearing housing (25), bearing outer ring baffle I (2101), bearing housing I (2102), several bearings (2103), several oil injection pipes I (2104), several bearing inner ring baffles I (2202), several windshields I (2203), several split gear shafts ( 2204), center wheel I (2205), center spline shaft I (2206), bearing housing II (2301), several bearing outer retaining rings (2302), several bearings (2303), several bearing inner retaining rings (2304), several bearing outer ring baffles II (2305), center spline shaft II (2401), center wheel II (2402), several bearing inner ring baffles II (2403), several parallel gear shafts (2404), several wind shields II (2405), bearing housing III (2501), several bearing outer ring baffles III (2502), several bearings (2503), several lubrication pipes II (2504). Detailed Implementation

[0021] The present invention will be further described below with reference to embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the scope of protection of the present invention.

[0022] Example 1:

[0023] A star-shaped multi-axis gear transmission system for an aircraft engine, characterized in that it includes an input shaft (01), a gear transmission system (02), and an output shaft (03);

[0024] The input shaft (01) and output shaft (03) are respectively connected to the power input end and output end of the gear transmission system (02) through an external spline structure. In the embodiment, the input shaft (01) is connected to the gear transmission system (02) through an external spline structure and is splined with the gear transmission system (02); the output shaft (03) is connected to the gear transmission system (02) through an external spline structure and is splined with the gear transmission system (02). Preferably, the spline structure can have a floating margin in the radial direction, which can improve the load sharing capacity of the gearbox in the process of "splitting" and "parallel driving", that is, improve the load sharing capacity in the circumferential direction in the process of "splitting" and "parallel driving".

[0025] The gear transmission system (02) mainly includes a split transmission part (22) and a parallel transmission part (23) installed in the casing (0206), as well as several elastic load-sharing shafts (0204) for connecting the split transmission part (22) and the parallel transmission part (23);

[0026] The diversion transmission part includes a central spline shaft I (2206), a central wheel I (2205), and a number of diversion gear shafts (2204) equal to the number of elastic load-sharing shafts (0204); the inner holes of the plurality of diversion gear shafts I (2204) are interference-fitted with the outer circles of the elastic load-sharing shafts (0204); gear teeth are machined on the outer circles of the diversion gear shafts (2204) to form a gear structure; the central wheel I (2205) is mounted on the spline shaft I (2206); the spline shaft I (2206) is the power input end of the gear transmission system (02); the central wheel I (2205) is a gear that meshes with the surrounding plurality of diversion gear shafts (2204); the gear is a cylindrical herringbone gear; furthermore, the diversion transmission part also includes a plurality of bearing inner ring baffles I (2202) and a plurality of wind shields I (2203);

[0027] The parallel drive system includes a central splined shaft II (2401), a central wheel II (2402), and a number of parallel gear shafts (2404) equal to the number of elastic load-sharing shafts (0204). The outer circumference of each parallel gear shaft (2404) is machined with gear teeth to form a gear structure. Each of the parallel gear shafts (2404) is designed with an internal spline structure and splines into contact with the elastic load-sharing shaft (0204). The central wheel II (2402) is mounted on the splined shaft II (2401). The splined shaft II (2401) is the power output end of the gear transmission system (02).

[0028] Wheel II (2402) is a gear that meshes with several parallel gear shafts (2404) around it; the gear is a cylindrical herringbone gear; furthermore, the parallel transmission part also includes several bearing inner ring baffles II (2403) and several windshields II (2405);

[0029] By changing the transmission ratio between the central wheel I (2205) and the split gear shaft (2204) and the transmission ratio between the central wheel II (2402) and the parallel gear shaft (2404), the gear transmission system (02) can be accelerated or decelerated. During operation, the power is first transmitted to the central wheel I (2205) through the central spline shaft I (2206), then to several split gear shafts (2204) that mesh with the central wheel I (2205), then to several parallel gear shafts (2404) through the elastic load-sharing shaft (0204) that is interference-fitted with several split gear shafts (2204), and finally to the central wheel II (2402) that meshes with several parallel gear shafts (2404).

[0030] It is worth noting that the transmission system disclosed in this embodiment is a star-shaped gear transmission mechanism based on the theory of "first splitting and then paralleling". The high-speed, high-power aero-engine star-shaped multi-shaft gear transmission system (02) has an input shaft (01) and an output shaft (03) that are coaxial and rotate in the same direction. The system can adjust the number of splitting gear shafts according to the transmission power, making the gear transmission system (02) more compact and smaller in size and weight. The elastic load-sharing shaft (0204) of the system adopts a structure of "one end with a stepped cylindrical structure interference fit and the other end with a spline", which can improve the motion accuracy and contact accuracy of the gear transmission system. That is, it can adjust the relative angle relationship between the splitting gear shaft (2204) and the paralleling gear shaft (2404), reduce the cumulative error of the machining accuracy of the herringbone teeth at both ends, and improve the motion accuracy and contact accuracy of the gearbox.

[0031] Example 2:

[0032] The main structure of this embodiment is the same as that of embodiment 1. Furthermore, the gear structure of the split transmission part (22) and the parallel transmission part (24) is a cylindrical herringbone gear structure. The input end cover (0201) is fixed to the bearing seat I (2102) by screws; the connecting plate (0203) and the bearing seat I (2102) are fixed to the gearbox housing (0206) by screws; the plurality of bearings (2103) are installed in the bearing holes on the bearing seat I (2102); the bearing outer ring baffle I (2101) is fixed to the bearing seat I (2102) by screws; the plurality of oil injection pipes I (2104) are fixed to the bearing seat I (2102) by screws. The central wheel I (2205) and the central spline shaft I (2206) are splined together, and the axial movement of the central wheel I (2205) and the central spline shaft I (2206) is constrained by a lock nut and bearing spacers. The central wheel I (2205) meshes externally with several split gear shafts (2204). Several bearings are mounted at both ends of the several split gear shafts (2204). The inner holes of the several split gear shafts (2204) are constrained together with several elastic load-sharing shafts (0204) by an interference fit of a stepped cylindrical structure. The inner ring baffles I (2202) of the several bearings are fixed to the several split gear shafts (2204) by screws, restricting the axial displacement of the bearings and the elastic load-sharing shafts (0204). In this embodiment, the central wheel load-sharing at the input and output ends adopts a splined fit structure. The splined fit structure allows for radial floating margin, improving the gearbox's "split" performance.

[0033] The load-sharing capacity during the "parallel" process is improved, that is, the load-sharing capacity in the circumferential direction is increased during the "diversion" and "parallel" processes. The plurality of bearings (2303), the plurality of bearing outer retaining rings (2302), and the plurality of bearing inner retaining rings (2304) are installed in the bearing holes of bearing housing II (2301); the plurality of bearing outer ring baffles II (2305) are fixed to bearing housing II (2301) by screws to constrain the axial movement of the bearings; the plurality of wind deflectors I (2203) and the plurality of wind deflectors II (2405) are fixed to bearing housing III (2501) by screws to reduce the wind resistance generated by the high-speed rotation of the plurality of diversion gear shafts (2204) and the plurality of parallel gear shafts (2404), which is beneficial to the return of lubricating oil and the reduction of wind resistance loss. The central spline shaft II (2401) and the central wheel II (2402) are splined together, and the axial movement of the central wheel II (2402) and the central spline shaft II (2401) is constrained by the locking nut and the bearing spacer. The central wheel II (2402) meshes externally with a plurality of parallel gear shafts (2404). A plurality of bearings are mounted at both ends of the plurality of parallel gear shafts (2404). The internal splines of the plurality of parallel gear shafts (2404) are splined together with a plurality of elastic load-sharing shafts (0204). The inner ring baffles II (2403) of the plurality of bearings are fixed to the plurality of parallel gear shafts (2404) by screws to restrict the axial movement of the bearings. In this embodiment, an elastic load-sharing shaft (0204) is used to transmit power and speed between the split gear shaft (2204) and the parallel gear shaft (2404). The elastic load-sharing shaft (0204) ensures that the transmission power on each split gear shaft (2204) and the parallel gear shaft (2404) is basically the same through its own torsional deformation, that is, it improves the consistency of the transmission power on each transmission shaft before "splitting" and "parallelizing". The output end cover (0205) is fixed to the bearing housing III (2501) with screws; the bearing housing III (2501) is fixed to the gearbox casing (0206) with screws; the plurality of bearings (2503) are installed in the bearing holes on the bearing housing III (2501); the plurality of bearing outer ring baffles III (2502) are fixed to the bearing housing III (2501) with screws; the plurality of fuel injection pipes II (2504) are fixed to the bearing housing III (2501) with screws.

[0034] Example 3:

[0035] The main structure of this embodiment is the same as that of Embodiment 1 or 2. Further, the casing (0206) also includes an intermediate bearing housing between the split-drive section (22) and the parallel-drive section (23); the intermediate bearing housing is used to install bearings supporting the split-drive shaft (2204) and the parallel-drive shaft (2404). The intermediate bearing housing includes bearing housing II (2301), several bearings (2303), several outer bearing retaining rings (2302), several inner bearing retaining rings (2304), and several outer bearing retaining plates II (2305); the bearing housing II (2301) is designed with lubrication channels; the bearing housing II (2301) is designed with static sealing grooves.

[0036] The gearbox housing (0206) is a cylindrical structure with open ends and a basically hollow interior. The housing (0206) has a lubricating oil inlet, a lubricating oil return, a vent, and a lubricating oil passage. The front opening of the housing (0206) is sealed by bearing housing I (2102) and an input end cover (0201). The input end cover (0201) is designed with a static sealing groove, a dynamic sealing groove, and a return oil hole. The rear opening of the housing (0206) is sealed by bearing housing III (2501) and an output end cover (0205). The output end cover (0205)...

[0037] The design includes a static sealing groove and a dynamic sealing mounting groove.

[0038] The input end bearing housing (21) includes a bearing housing I (2102), a plurality of bearings (2103), a plurality of oil injection pipes I (2104), and a bearing outer ring baffle I (2101); the bearing housing I (2102) is designed with a lubrication oil passage; the bearing housing I (2102) is designed with a static sealing groove; the input end cover (0201) is fixed to the bearing housing I (2102) with screws; the connecting plate (0203) and the bearing housing I (2102) are fixed to the gearbox housing (0206) with screws; the plurality of bearings (2103) are installed in the bearing holes on the bearing housing I (2102); the bearing outer ring baffle I (2101) is fixed to the bearing housing I (2102) with screws; the plurality of oil injection pipes I (2104) are fixed to the bearing housing I (2102) with screws.

[0039] The output end cap (0205) is fixed to the bearing housing III (2501) with screws; the bearing housing III (2501) is fixed to the gearbox casing (0206) with screws; the plurality of bearings (2503) are installed in the bearing holes on the bearing housing III (2501); the plurality of bearing outer ring baffles III (2502) are fixed to the bearing housing III (2501) with screws;

[0040] The plurality of fuel injection pipes II (2504) are fixed to bearing housing III (2501) by screws.

[0041] Example 4:

[0042] The main structure of this embodiment is the same as any one of embodiments 1 to 3. Further, the central spline shaft I (2206) and the central wheel I (2205) are spline-fitted. The spline fit structure can have a floating margin in the radial direction, which improves the load-sharing capacity of the gearbox during the "splitting" process, that is, improves the load-sharing capacity in the circumferential direction during the "splitting" process. Several bearings are installed at both ends of the several splitting gear shafts (2204). The central wheel I (2205) meshes externally with the several splitting gear shafts (2204). The inner ring baffles I (2202) of the several bearings are fixed to the several splitting gear shafts (2204) by screws, which restricts the axial displacement of the bearings and the elastic load-sharing shaft (0204).

[0043] The center spline shaft II (2401) and the center wheel II (2402) are installed with a spline fit;

[0044] The spline fit structure can have a floating margin in the radial direction, which improves the load-sharing capacity of the gearbox during the "parallel operation" process, that is, improves the load-sharing capacity in the circumferential direction during the "parallel operation" process.

[0045] Several bearings are installed at both ends of the plurality of parallel gear shafts (2404); the central wheel II (2402) meshes externally with the plurality of parallel gear shafts (2404); the inner ring baffles II (2403) of the plurality of bearings are fixed to the plurality of parallel gear shafts (2404) by screws to restrict the axial movement of the bearings.

[0046] A plurality of split-type gear shafts (2204) and a plurality of parallel-type gear shafts (2404) are connected by an elastic load-sharing shaft (0204) for power and speed transmission. The inner bores of the plurality of split-type gear shafts (2204) and the plurality of elastic load-sharing shafts (0204) are constrained together by an interference fit of a stepped cylindrical structure. The splines inside the plurality of parallel-type gear shafts (2404) are connected to the plurality of elastic load-sharing shafts (0204) by a spline fit. The elastic load-sharing shaft (0204) has a structure of "one end with an interference fit of a stepped cylindrical structure and the other end with a spline" at both ends, which can adjust the relative angle relationship between the split-type gear shafts (2204) and the parallel-type gear shafts (2404), reduce the cumulative error of the machining accuracy of the herringbone teeth at both ends, and improve the motion accuracy and contact accuracy of the gearbox. The elastic load-sharing shaft (0204) ensures the connection between each split-type gear shaft (2204) and the parallel-type gear shaft (2404) through its own torsional deformation.

[0047] The transmission power on the gear shaft (2404) is basically consistent, that is, the consistency of transmission power on each transmission shaft is improved after "splitting" and before "parallel driving".

[0048] Bearing housing III (2501) is fixed to the output end cover (0205). The bearing housing III (2501) and the output end cover (0205) are fitted with a shaft hole. The output end cover (0205) and the bearing housing III (2501) are fitted with a shaft hole. The outer rings of the plurality of bearings (2503) are fitted and installed with the bearing housing III (2501).

Claims

1. A star-shaped multi-axis gear transmission system for an aero-engine, characterized in that: Includes input shaft (01), gear transmission system (02), and output shaft (03); The input shaft (01) and output shaft (03) are respectively connected to the power input end and output end of the gear transmission system (02) through an external spline structure; The gear transmission system (02) mainly includes a split transmission part (22) and a parallel transmission part (23) installed in the casing (0206), as well as a number of elastic load-sharing shafts (0204) for connecting the split transmission part (22) and the parallel transmission part (23). The split-drive section includes a central spline shaft I (2206), a central wheel I (2205), and a number of split-drive gear shafts (2204) equal to the number of elastic load-sharing shafts (0204); the inner holes of several split-drive gear shafts I (2204) are interference-fitted with the outer circles of the elastic load-sharing shafts (0204); gear teeth are machined on the outer circles of the split-drive gear shafts (2204) to form a gear structure; the central wheel I (2205) is mounted on the spline shaft I (2206); the spline shaft I (2206) is the power input end of the gear transmission system (02); the central wheel I (2205) is a gear that meshes with several surrounding split-drive gear shafts (2204); the gear is a cylindrical herringbone gear; The parallel drive system includes a central spline shaft II (2401), a central wheel II (2402), and a number of parallel gear shafts (2404) equal to the number of elastic load-sharing shafts (0204). The outer circumference of each parallel gear shaft (2404) is machined with gear teeth to form a gear structure. Each parallel gear shaft (2404) is designed with an internal spline structure and splines into contact with the elastic load-sharing shaft (0204). The central wheel II (2402) is mounted on the spline shaft II (2401). The spline shaft II (2401) is the power output end of the gear transmission system (02). The central wheel II (2402) is a gear that meshes with the surrounding parallel gear shafts (2404). The gear is a cylindrical herringbone gear. By changing the transmission ratio between the central wheel I (2205) and the split gear shaft (2204) and the transmission ratio between the central wheel II (2402) and the parallel gear shaft (2404), the gear transmission system (02) can be accelerated or decelerated. During operation, the power is first transmitted to the central wheel I (2205) through the central spline shaft I (2206), then to several split gear shafts (2204) that mesh with the central wheel I (2205), then to several parallel gear shafts (2404) through the elastic load-sharing shaft (0204) that is interference-fitted with several split gear shafts (2204), and finally to the central wheel II (2402) that meshes with several parallel gear shafts (2404).

2. The star-shaped multi-axis gear transmission system for an aero-engine according to claim 1, characterized in that: The casing (0206) also includes an intermediate bearing housing between the split drive section (22) and the parallel drive section (23); the intermediate bearing housing is used to install bearings supporting the center spline shaft I (2206), the split gear shaft (2204), the parallel gear shaft (2404) and the center spline shaft II (2401).

3. The star-shaped multi-axis gear transmission system for an aero-engine according to claim 1, characterized in that: The casing (0206) is a cylindrical structure with open ends and a basically hollow interior. The casing (0206) has a lubricating oil inlet, a lubricating oil return, a vent, and a lubricating oil passage. The front end of the casing (0206) is sealed with a bearing seat I (2102) and an input end cover (0201). The rear end of the casing (0206) is sealed with a bearing seat III (2501) and an output end cover (0205).

4. A star-shaped multi-axis gear transmission system for an aero-engine according to claim 3, characterized in that: The input end cap (0201) is fixed to the bearing housing I (2102) with screws; the connecting plate (0203) and the bearing housing I (2102) are fixed to the gearbox casing (0206) with screws; a number of bearings (2103) are installed in the bearing holes on the bearing housing I (2102); the bearing outer ring baffle I (2101) is fixed to the bearing housing I (2102) with screws; a number of oil injection pipes I (2104) are fixed to the bearing housing I (2102) with screws.

5. A star-shaped multi-axis gear transmission system for an aero-engine according to claim 4, characterized in that: The output end cap (0205) is fixed to the bearing housing III (2501) by screws; the bearing housing III (2501) is fixed to the gearbox casing (0206) by screws; a number of bearings (2503) are installed in the bearing holes on the bearing housing III (2501); a number of bearing outer ring baffles III (2502) are fixed to the bearing housing III (2501) by screws; a number of oil injection pipes II (2504) are fixed to the bearing housing III (2501) by screws.

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