Aero-engine flexible spline coupling with elastic clamping tongue

Abstract

The invention discloses an aero-engine flexible spline coupling with an elastic clamping tongue, and belongs to the technical field of aero-engines. The coupler comprises a fan shaft, a low-pressure turbine shaft, a centering compensation part, a locking part and an elastic clamping tongue, the fan shaft is a hollow shaft, an annular boss is integrally formed in the fan shaft, one end of the low-pressure turbine shaft is inserted into the fan shaft, is in sliding connection with the annular boss and is in transmission connection with the fan shaft, and the other end of the low-pressure turbine shaft is in transmission connection with the locking part. The centering compensation part is located in a radial gap between the fan shaft and the low-pressure turbine shaft, the locking part is arranged on the low-pressure turbine shaft in a sleeving mode, the centering compensation part and the annular boss jointly conduct axial limiting on the centering compensation part, and the elastic clamping tongue is located in a radial gap between the locking part and the low-pressure turbine shaft and conducts rotation stopping on the locking part and the low-pressure turbine shaft. The elastic clamping tongue can bear larger shearing force, and locking of the locking piece is more reliable and effective. And the centering compensation piece is not easy to wear and long in service life. The whole assembling process of the coupler is simple.

Description

Technical Field

[0001] The invention relates to an aero-engine flexible spline coupling with an elastic clamping tongue, belonging to the technical field of aero-engines. Background Art

[0002] The coupling is an important device that connects the driving shaft and the driven shaft to rotate together and transmit motion and torque. The fan shaft and low-pressure turbine shaft in the low-pressure rotor of an aircraft engine are key power transmission components of the engine. They have the characteristics of long span, high operating speed, and large transmission torque. The two shafts are usually connected by a spline coupling. As international military competition intensifies, countries have higher requirements for air supremacy, which requires aircraft engines to have better performance, that is, the low-pressure shaft system must have a higher speed and greater transmission torque. The harsh working environment requires higher locking performance and centering compensation performance of the spline coupling.

[0003] For example, the Chinese patent document with publication number CN111946403A discloses a coupling for connecting aviation rotors, in which the fan shaft and the turbine rotor shaft are sleeved and assembled, and sets of splines are designed on them to realize the function of transmitting torque. The coupling relies on a sleeve nut to tighten the two rotating shafts, relies on spherical washers arranged in pairs to realize the connection compensation for rotor misalignment, and the slidable spline bushing relies on the spring force to stop the tightened sleeve nut. The coupling only needs to realize the connection function. The present invention strips the torque transmission function of the coupling, and the coupling only needs to realize the connection function, with a small working load, a simple structure, high reliability, and easy promotion.

[0004] However, the coupling still has the following shortcomings:

[0005] First, poor reliability: in terms of locking and preventing loosening of the sleeve nut, the shear force is borne by the pin, and the shear force that the pin can withstand is small; in addition, the locking and preventing loosening of the sleeve nut is achieved by the cooperation of the spline bushing, spring, limit bushing and pin. There are many anti-loosening parts. The failure of any part will lead to the failure of the locking and preventing loosening function of the sleeve nut, and the reliability is poor.

[0006] Second, the parts are easy to wear: the rotor centering compensation is achieved through the relative sliding of the concave spherical washer and the convex spherical washer. The concave spherical washer and the convex spherical washer are easy to wear and have a short service life.

[0007] Third, the assembly is complicated: the turbine rotor shaft, limit bushing and spline bushing need to be connected by pins first, and then one end of the turbine rotor shaft is inserted into the fan shaft, and then the spline bushing is pressed into the turbine rotor shaft using a tool. Next, the internal spline is used to rotate the sleeve nut to tighten the turbine rotor shaft and the fan shaft. Finally, the spline bushing is loosened, and the spline bushing is reset under the action of the spring force, and the external spline on it is inserted into the internal spline on the sleeve nut. The entire assembly process is relatively complicated. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides an aircraft engine flexible spline coupling with an elastic tongue.

[0009] The present invention is achieved through the following technical solutions:

[0010] A flexible spline coupling for an aircraft engine with an elastic tongue comprises a fan shaft, a low-pressure turbine shaft, a centering compensating piece, a locking piece and an elastic tongue, wherein the fan shaft is a hollow shaft, and an annular boss is integrally formed in the fan shaft, one end of the low-pressure turbine shaft is inserted into the fan shaft, is slidably connected to the annular boss, and is drivingly connected to the fan shaft, the centering compensating piece is located in a radial gap between the fan shaft and the low-pressure turbine shaft, the locking piece is sleeved on the low-pressure turbine shaft, and together with the annular boss, axially limits the centering compensating piece, the elastic tongue is located in a radial gap between the locking piece and the low-pressure turbine shaft, and stops the locking piece and the low-pressure turbine shaft from rotating.

[0011] The cylindrical positioning surface C on the low-pressure turbine shaft is in clearance fit with the annular boss.

[0012] An annular groove A is circumferentially provided on the cylindrical positioning surface C of the low-pressure turbine shaft, and a sealing ring is installed at the annular groove A to seal the radial gap between the cylindrical positioning surface C and the annular boss.

[0013] An inner spline is arranged on the inner wall of the fan shaft, and the inner spline is located on the side of the annular boss away from the locking member. An outer spline is arranged on the low-pressure turbine shaft, and the outer spline is meshed with the inner spline.

[0014] When the centering compensating member is in contact with the locking member and the annular boss, an axial clearance N exists between the external spline on the low-pressure turbine shaft and the annular boss.

[0015] The centering compensation piece is an elastic ring, which is clearance-matched with the fan shaft, and a plurality of annular grooves are provided on the inner wall and the outer wall of the elastic ring.

[0016] The locking member is a nut, which is threadedly connected to the external thread on the low-pressure turbine shaft.

[0017] The inner wall of the nut is provided with a plurality of slots M in a circumferential array, and the outer circumferential surface of the low-pressure turbine shaft is also provided with a plurality of long slots H in a circumferential array;

[0018] The inner wall of the nut is provided with an inner diameter surface X 1 , and the inner diameter surface X 1 A tongue groove P is provided in the middle of the circumferential direction, and the diameter of the tongue groove P is φ 2 The outer diameter surface X is provided on the outer diameter surface of the low pressure turbine shaft. 2 .

[0019] The elastic tongue includes a tongue block K, which is arc-shaped and has an outer diameter of φ 1 A clamping block J is integrally formed in the middle of the tongue block K. The outer diameter and inner diameter of the clamping block J are consistent with the outer diameter and inner diameter of the tongue block K, and the axial width of the clamping block J is greater than the axial width of the tongue block K. A stop block L is integrally formed at one axial end of the clamping block J.

[0020] The outer diameter φ of the tongue K 1 Than the diameter of the tongue groove Pφ 2 big.

[0021] The beneficial effects of the present invention are:

[0022] 1. The coupling locking form is novel and suitable for high-speed, high-torque aircraft engines. After the locking piece is mounted on the low-pressure turbine shaft, the locking piece is prevented from loosening by the elastic tongue; the stop block L on the elastic tongue is inserted into the long strip slot H on the low-pressure turbine shaft and the slot M on the locking piece to achieve circumferential stopping, and the tongue block K on the elastic tongue is ejected and inserted into the tongue slot P on the locking piece to achieve axial stopping, that is, the circumferential stopping and axial stopping are respectively undertaken by different parts of the elastic tongue, which can withstand greater shear force than the pin in the prior art, and the locking piece can be prevented from loosening by a single-part elastic tongue, which is more reliable and effective in locking the locking piece.

[0023] 2. The centering compensation part realizes compression and bending and torsion performance through multiple annular grooves on its inner and outer walls. When the engine is working, the axial forces of the fan shaft and the low-pressure turbine shaft are opposite, and the elastic ring is compressed. If the fan shaft and the low-pressure turbine shaft are eccentric, the annular grooves on the elastic ring can be used to realize the centering compensation of the two connected rotors. The centering compensation part can realize the centering compensation of the two connected rotors through a single part, and the centering compensation part is not easy to wear and has a long service life.

[0024] 3. After pressing the centering compensation part into the fan shaft along the G direction, insert one end of the low-pressure turbine shaft into the fan shaft, then put the locking part on the low-pressure turbine shaft, and then insert the elastic tongue into the radial gap between the locking part and the low-pressure turbine shaft. The locking part and the low-pressure turbine shaft are stopped to complete the assembly. The whole assembly process is relatively simple.

[0025] 4. The torque transmission, axial force transmission and centering compensation functions of the coupling are undertaken by different components, which can effectively improve the reliability and life of the engine. The overall structure is simple, the installation space requirement is small, it is easy to design and reference, easy to assemble and maintain, and the use cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention;

[0027] Figure 2 for Figure 1 A partial enlarged view at position Ⅰ;

[0028] Figure 3 for Figure 1 Along H 1 A partial enlarged view of a location where a long strip-shaped slot H is opened on the low-pressure turbine shaft;

[0029] Figure 4 It is a schematic structural diagram of the elastic latch tongue of the present invention;

[0030] Figure 5 It is a schematic diagram of the front view structure of the elastic latch of the present invention;

[0031] Figure 6 for Figure 5 A schematic diagram of a top view structure;

[0032] Figure 7 It is a schematic diagram of the main structure of the nut of the present invention;

[0033] Figure 8 It is a partial view of the nut of the present invention.

[0034] In the figure: 1-fan shaft, 10-annular boss, 2-elastic tongue, 3-locking piece, 4-centering compensation piece, 40-annular groove, 5-sealing ring, 6-low-pressure turbine shaft.

[0035] C-cylindrical locating surface, D-connecting thread between nut and low-pressure turbine shaft, E-connecting spline between fan shaft and low-pressure turbine shaft, H-long slot, J-block, K-tongue block, L-stop block, M-slot, N-axial clearance, P-tongue slot, X 1 -Inner diameter surface, X 2 -Outer diameter surface, φ 1 -Outer diameter of tongue K φ 1 ,φ 2 - Diameter of the tongue groove P. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0037] like Figures 1 to 8As shown, an aircraft engine flexible spline coupling with an elastic tongue described in the present invention comprises a fan shaft 1, a low-pressure turbine shaft 6, a centering compensating piece 4, a locking piece 3 and an elastic tongue 2, wherein the fan shaft 1 is a hollow shaft, and an annular boss 10 is integrally formed in the fan shaft 1, one end of the low-pressure turbine shaft 6 is inserted into the fan shaft 1, is slidably connected to the annular boss 10, and is transmission-connected to the fan shaft 1, the centering compensating piece 4 is located in the radial gap between the fan shaft 1 and the low-pressure turbine shaft 6, the locking piece 3 is sleeved on the low-pressure turbine shaft 6, and together with the annular boss 10, axially limits the centering compensating piece 4, the elastic tongue 2 is located in the radial gap between the locking piece 3 and the low-pressure turbine shaft 6, and stops the locking piece 3 and the low-pressure turbine shaft 6 from rotating. When in use, after the locking piece 3 is mounted on the low-pressure turbine shaft 6, the locking piece 3 is prevented from loosening by the elastic latch 2; the elastic latch 2 can withstand a large shear force, and the locking piece 3 can be prevented from loosening by a single elastic latch 2, which has good reliability. When the fan shaft 1 is eccentric relative to the low-pressure turbine shaft 6, the centering compensation piece 4 can be used to compensate for the centering of the two connected rotors. The centering compensation piece 4 is not easy to wear and has a long service life. Figure 1 As shown, after the centering compensation part 4 is pressed into the fan shaft 1 along the G direction, one end of the low-pressure turbine shaft 6 is inserted into the fan shaft 1, and then the locking part 3 is put on the low-pressure turbine shaft 6, and then the elastic tongue 2 is inserted into the radial gap between the locking part 3 and the low-pressure turbine shaft 6, and the locking part 3 and the low-pressure turbine shaft 6 are stopped to complete the assembly. The whole assembly process is relatively simple.

[0038] The cylindrical positioning surface C on the low-pressure turbine shaft 6 is matched with the annular boss 10 with a small clearance.

[0039] The cylindrical positioning surface C of the low-pressure turbine shaft 6 is provided with an annular groove A along the circumferential direction, and a sealing ring 5 is installed at the annular groove A to seal the radial gap between the cylindrical positioning surface C and the annular boss 10. Figure 1 As shown, the lubricating oil flows into the radial clearance between the fan shaft 1 and the low-pressure turbine shaft 6 along the F direction to lubricate the inner splines and the outer splines, and the radial clearance between the cylindrical positioning surface C and the annular boss 10 is sealed by the sealing ring 5 to prevent the lubricating oil from flowing to the centering compensation part 4.

[0040] The inner wall of the fan shaft 1 is provided with an inner spline, and the inner spline is located on the side of the annular boss 10 away from the locking member 3. The low-pressure turbine shaft 6 is provided with an outer spline, and the outer spline meshes with the inner spline. When in use, the inner spline on the fan shaft 1 cooperates with the outer spline on the low-pressure turbine shaft 6 to achieve motion and torque transmission.

[0041] When the centering compensating member 4 is in contact with the locking member 3 and the annular boss 10, there is an axial clearance N between the external spline on the low-pressure turbine shaft 6 and the annular boss 10. When in use, the axial clearance N is designed between the external spline of the low-pressure turbine shaft 6 and the annular boss 10 to prevent the external spline from colliding with the annular boss 10.

[0042] The centering compensating member 4 is an elastic ring, which is loosely matched with the fan shaft 1, and a plurality of annular grooves 40 are provided on the inner and outer walls of the elastic ring. When in use, the centering compensating member 4 realizes compression and bending and torsion performance through the plurality of annular grooves 40 on the inner and outer walls. When the engine is working, the axial forces of the fan shaft 1 and the low-pressure turbine shaft 6 are opposite, and the elastic ring is compressed. If the fan shaft 1 and the low-pressure turbine shaft 6 are eccentric, the centering compensation of the two connected rotors can be realized through the annular grooves 40 on the elastic ring.

[0043] The locking member 3 is a nut which is threadedly connected to an external thread on the low-pressure turbine shaft 6 .

[0044] The inner wall of the nut is provided with a plurality of slots M in a circumferential array, and the outer circumferential surface of the low-pressure turbine shaft 6 is also provided with a plurality of long slots H in a circumferential array;

[0045] The inner wall of the nut is provided with an inner diameter surface X 1 , and the inner diameter surface X 1 A tongue groove P is provided in the middle of the circumferential direction, and the diameter of the tongue groove P is φ 2 The outer diameter surface X is provided on the outer circumference of the low-pressure turbine shaft 6. 2 When in use, the width of the card slot M is consistent with that of the long strip card slot H, and is slightly wider than the width of the stop block L. The width of the card tongue slot P along the axial direction is slightly wider than the width of the tongue block K along the axial direction.

[0046] The elastic tongue 2 includes a tongue block K, which is arc-shaped and has an outer diameter of φ 1 A clamping block J is integrally formed in the middle of the tongue block K. The outer diameter and inner diameter of the clamping block J are consistent with the outer diameter and inner diameter of the tongue block K, and the axial width of the clamping block J is greater than the axial width of the tongue block K. A stop block L is integrally formed at one axial end of the clamping block J.

[0047] The outer diameter φ of the tongue K 1 Than the diameter of the tongue groove Pφ 2 big.

[0048] The assembly process of the flexible spline coupling of an aero-engine with an elastic tongue of the present invention is as follows:

[0049] Before assembly, apply HR-5211 high-temperature grease on the threads and spline surfaces of the fan shaft 1, locking piece 3, and low-pressure turbine shaft 6.

[0050] During assembly, first install the sealing ring 5 into the annular groove A at the cylindrical positioning surface C on the low-pressure turbine shaft 6, then press the centering compensation part 4 into the fan shaft 1 along the G direction, and then insert one end of the low-pressure turbine shaft 6 with the sealing ring 5 into the fan shaft 1. The fan shaft 1 and the low-pressure turbine shaft 6 are connected through internal splines and external splines. Next, thread the locking piece 3 and the low-pressure turbine shaft 6, and after pre-tightening the locking piece 3 according to the torque requirement, check whether any of the long strip slots H are aligned with any of the slots M. If not, continue to adjust the torque to align the long strip slots H with any of the slots M. If yes, place the stop block L of the elastic latch 2 in the corresponding long strip slot H, and then adjust the tongue block K and the block J, press them into the annular gap formed by the locking piece 3 and the low-pressure turbine shaft 6, and then push the elastic latch 2 to the bottom along the G direction. After the elastic latch 2 is pushed into place, the tongue block K pops up and embeds into the tongue groove P on the inner surface of the locking piece 3 to play a locking role. The width of the tongue block K is slightly narrower than the width of the tongue groove P, and the outer diameter of the tongue block K is φ 1 Diameter of tongue groove P 2 The width of the slot M is consistent with that of the long strip slot H, and is slightly wider than the width of the stopper L, which not only ensures the pushing property of the elastic tongue 2, but also plays a circumferential limiting role on the locking member 3 and the low-pressure turbine shaft 6 through the stopper L; the block J is locked by the inner diameter surface X of the locking member 3. 1 and the outer diameter surface X on the low-pressure turbine shaft 6 2 Press tightly to ensure the installation stability and installation reliability of the elastic tongue 2. After the elastic tongue 2 is assembled in place, it is necessary to pull the elastic tongue 2 in the opposite direction of the G direction to check whether the tongue block K is stuck.

Claims

1. An aircraft engine flexible spline coupling with an elastic tongue, characterized in that: The invention comprises a fan shaft (1), a low-pressure turbine shaft (6), a centering compensating member (4), a locking member (3) and an elastic latch (2); the fan shaft (1) is a hollow shaft, and an annular boss (10) is integrally formed in the fan shaft (1); one end of the low-pressure turbine shaft (6) is inserted into the fan shaft (1), is slidably connected to the annular boss (10), and is transmission-connected to the fan shaft (1); the centering compensating member (4) is located in a radial gap between the fan shaft (1) and the low-pressure turbine shaft (6); the locking member (3) is sleeved on the low-pressure turbine shaft (6), and together with the annular boss (10) axially limits the centering compensating member (4); the elastic latch (2) is located in a radial gap between the locking member (3) and the low-pressure turbine shaft (6), and stops the locking member (3) and the low-pressure turbine shaft (6) from rotating.

2. The flexible spline coupling of an aircraft engine with an elastic tongue as claimed in claim 1, characterized in that: The cylindrical positioning surface C on the low-pressure turbine shaft (6) is clearance-matched with the annular boss (10).

3. The flexible spline coupling of an aircraft engine with an elastic tongue as claimed in claim 2, characterized in that: An annular groove A is provided on the cylindrical positioning surface C of the low-pressure turbine shaft (6) along the circumferential direction, and a sealing ring (5) is installed at the annular groove A to seal the radial gap between the cylindrical positioning surface C and the annular boss (10).

4. The flexible spline coupling of an aircraft engine with an elastic tongue as claimed in claim 1, characterized in that: An internal spline is provided on the inner wall of the fan shaft (1), and the internal spline is located on the side of the annular boss (10) away from the locking member (3). An external spline is provided on the low-pressure turbine shaft (6), and the external spline meshes with the internal spline.

5. The flexible spline coupling of an aircraft engine with an elastic tongue as claimed in claim 1, characterized in that: When the centering compensating member (4) is in contact with the locking member (3) and the annular boss (10), an axial clearance N exists between the external spline on the low-pressure turbine shaft (6) and the annular boss (10).

6. The flexible spline coupling of an aircraft engine with an elastic tongue as claimed in claim 1, characterized in that: The centering compensation piece (4) is an elastic ring which is clearance-matched with the fan shaft (1), and a plurality of annular grooves (40) are provided on the inner wall and the outer wall of the elastic ring.

7. The flexible spline coupling of an aircraft engine with an elastic tongue as claimed in claim 1, characterized in that: The locking member (3) is a nut which is threadedly connected to an external thread on the low-pressure turbine shaft (6).

8. The aircraft engine flexible spline coupling with elastic tongue according to claim 7, characterized in that: The inner wall of the nut is provided with a plurality of slots M in a circumferential array, and the outer circumferential surface of the low-pressure turbine shaft (6) is also provided with a plurality of long strip slots H in a circumferential array; An inner diameter surface X1 is provided on the inner wall of the nut, and a latch tongue groove P is provided in the middle of the inner diameter surface X1 along the circumferential direction. The diameter of the latch tongue groove P is φ2. An outer diameter surface X2 is provided on the outer circumferential surface of the low-pressure turbine shaft (6).

9. The aircraft engine flexible spline coupling with elastic tongue according to claim 8, characterized in that: The elastic tongue (2) comprises a tongue block K, which is in an arc shape and has an outer diameter of φ1. A clamping block J is integrally formed in the middle of the tongue block K. The outer diameter and inner diameter of the clamping block J are consistent with those of the tongue block K, and the axial width of the clamping block J is greater than the axial width of the tongue block K. A stop block L is integrally formed at one axial end of the clamping block J.

10. The aircraft engine flexible spline coupling with elastic tongue according to claim 9, characterized in that: The outer diameter φ1 of the tongue block K is larger than the diameter φ2 of the tongue groove P.

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