A grommet connection structure and a cantilevered support rotor system

Abstract

The application provides a toothed sleeve connecting structure and a cantilever support rotor system, and belongs to the field of aeroengines. The toothed sleeve connecting structure comprises a toothed sleeve outer shaft fixedly connected with a turbine rotor, a limiting protrusion is arranged on the outer surface of the side of the toothed sleeve outer shaft away from the turbine rotor, a rear support column is arranged on the inner surface of the side of the toothed sleeve outer shaft close to the turbine rotor, and a first tooth is arranged on the inner surface of the toothed sleeve outer shaft; a toothed sleeve inner shaft is arranged, a second tooth matched with the first tooth is arranged on the outer surface of the toothed sleeve inner shaft, step structures are arranged on the outer surface of the toothed sleeve inner shaft on both sides of the second tooth, the end of the toothed sleeve outer shaft and the rear support column are arranged at the two step structures of the toothed sleeve inner shaft to form matched front and rear column surfaces, the toothed sleeve inner shaft extends a tensioning part towards the side of the turbine rotor; a limiting ring is arranged on the outside of the tensioning part of the toothed sleeve inner shaft, and the limiting ring is abutted on the rear support column through an axial compression nut; a rear support point bearing is installed on the toothed sleeve outer shaft and located at the connecting interface position of the toothed sleeve outer shaft and the toothed sleeve inner shaft, and the rear support point bearing is axially limited through the limiting protrusion.

Description

Technical Field

[0001] This application belongs to the field of aero-engines, and specifically relates to a toothed connection structure and a cantilevered rotor system. Background Technology

[0002] Aero engines typically use a two-point support for the rotor, with the cantilever rotor system employing a 1-1-0 support being a common design. For example... Figure 1 The diagram shows a typical cantilever rotor system. The compressor rotor 1 on the left is supported by the first fulcrum 41 and the second fulcrum 42, while the turbine disk 2 on the right is cantilevered. The two are connected by a toothed connection structure 3. In this cantilever rotor system, the compressor rotor 1 has a small span between its fulcrums, while the turbine disk 2 has a large mass and is cantilevered. In order to drive the compressor rotor 1 with the large torque output from the turbine, a toothed connection structure 3 with strong torque transmission capability is required. During engine operation, the toothed connection structure 3 bears the aerodynamic axial load F1 of the compressor rotor 1, the initial assembly load of the turbine disk 3 (nut preload F4 and the tightness of the centering surface), centrifugal load, aerodynamic axial force F3, and bending load F2 caused by the inertial offset of the turbine disk's main shaft. Under this operating condition, the bending load F2 is prone to cause local circumferential separation of the toothed connection structure 3, which leads to a decrease in the interface constraint capacity of the toothed connection structure 3, loss of stiffness of the toothed connection structure 3, and insufficient working stability of the compressor rotor 1 at high speed. In addition, the bending load F2 is prone to cause excessive bending deformation of the toothed connection structure 3, and strong axial deformation incoordination between the inner and outer shafts of the toothed connection structure 3, resulting in axial slippage. Long-term operation will lead to interface fatigue damage and constraint damage. Summary of the Invention

[0003] The purpose of this application is to provide a toothed connection structure and a cantilevered rotor system to solve or mitigate at least one of the problems in the prior art.

[0004] The technical solution of this application is: a toothed connection structure, the toothed connection structure comprising:

[0005] A geared outer shaft is fixedly connected to a turbine rotor. The outer surface of the geared outer shaft away from the turbine rotor is provided with a limiting protrusion. The inner surface of the geared outer shaft near the turbine rotor is provided with a rear support column. The inner surface of the geared outer shaft is provided with a first tooth, which is located between the rear support column and the end.

[0006] The inner shaft with a gear sleeve has a second tooth on its outer surface that is adapted to the first tooth. The outer surface of the inner shaft with a gear sleeve has a stepped structure on both sides of the second tooth. The end of the outer shaft with a gear sleeve and the rear support are respectively located at the two stepped structures of the inner shaft with a gear sleeve to form a mating front cylindrical surface and a rear cylindrical surface. The inner shaft with a gear sleeve extends to one side of the turbine rotor with a tensioning part.

[0007] A limiting ring is provided on the outside of the tensioning part of the inner shaft of the sleeve gear, and the limiting ring is abutted against the rear support by an axial clamping nut;

[0008] The rear pivot bearing is mounted on the outer shaft of the sleeve gear and located at the connection interface between the outer shaft and the inner shaft of the sleeve gear. The rear pivot bearing is axially limited by the limiting protrusion.

[0009] In a preferred embodiment of this application, both the front cylindrical surface and the rear cylindrical surface are interference fits.

[0010] In a preferred embodiment of this application, the rear cylindrical surface has a tightness δ, which is the maximum value according to the standard.

[0011] In at least one embodiment of this application, the tightening torque of the axial clamping nut is M, which causes the outer shaft of the sleeve to be axially positioned on the vertical plane of the left step portion of the inner shaft of the sleeve.

[0012] In a preferred embodiment of this application, the tightening torque M is taken as the maximum value according to the standard.

[0013] In a preferred embodiment of this application, the front cylindrical surface and the rear cylindrical surface form an axial span L, which is as large as possible within the limits of structural space.

[0014] In at least one embodiment of this application, the thickness of the tensioning portion is less than the thinnest position of the inner shaft step structure of the sleeve tooth, thereby forming an elastic structure of the tensioning portion.

[0015] On the other hand, the technical solution provided in this application is: a cantilevered rotor system, the cantilevered rotor system including a compressor rotor and a turbine rotor, the compressor rotor and the turbine rotor being connected by a sleeve tooth connection structure as described above.

[0016] The sleeve-tooth connection structure and cantilever-supported rotor system provided in this application have the following advantages:

[0017] 1) It can reduce the stiffness loss of the sleeve tooth connection caused by bending load when the rotor is working at high speed, improve the interface constraint ability of the sleeve tooth connection structure, and improve the robustness.

[0018] 2) It can reduce the slippage of the sleeve tooth connection interface when the rotor is working at high speed, avoid fatigue damage and constraint damage at the contact interface, and improve robustness.

[0019] 3) By setting the sleeve tooth connection interface at the rear support bearing position, the stiffness of the sleeve tooth connection can be increased, the local deformation at the sleeve tooth connection can be reduced, and the centering interface can be guaranteed to have a good contact state, thereby reducing the axial slippage and interface deformation of the centering interface.

[0020] 4) By placing the axial position of the rear support bearing (hot end) close to the bending mode node, the front support bearing (cold end) bears a larger dynamic load of support constraint in the high speed range of the rotor, while the rear support bearing, which is in a higher ambient temperature, is subjected to a smaller dynamic load, which is beneficial to the stable operation of the rotor system. Attached Figure Description

[0021] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0022] Figure 1 This is a schematic diagram of a typical cantilevered rotor system using a toothed connection.

[0023] Figure 2 This is a schematic diagram of the toothed connection structure of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0025] To prevent the circumferential partial separation of the sleeve tooth connection structure caused by bending load during high-speed operation of the compressor rotor, resulting in a loss of stiffness in the sleeve tooth connection structure, and to prevent the inner and outer shafts of the sleeve tooth connection structure from axially slipping due to bending load during high-speed operation of the compressor rotor, resulting in fatigue damage and constraint damage at the contact interface, this application provides a sleeve tooth connection structure.

[0026] like Figure 2 As shown, the sleeve tooth connection structure 100 provided in this application includes a sleeve tooth outer shaft 110, a sleeve tooth inner shaft 120, an axial clamping nut 130, a turbine rotor 140, a rear support bearing 150, and a limiting ring 160.

[0027] The inner surface of the geared outer shaft 110 is provided with an axially extending first tooth 111, and the inner surface of the toothed outer shaft near the turbine disk 140 is provided with a radially extending rear support 112. Exemplarily, the rear support 112 can be a rear support formed by an annular protrusion, or it can be a rear support formed by circumferentially spaced bosses. Preferably, the rear support 112 is an annular protrusion. The right side of the geared outer shaft 110 is fixedly connected to the turbine rotor 140, which has a turbine disk in a cantilevered state. Exemplarily, the geared outer shaft 110 and the turbine rotor 140 can be fixedly connected by bolts, or they can be fixedly connected by welding.

[0028] The outer surface of the inner gear shaft 120 is provided with an axially extending second tooth 121, which is used to engage with the first tooth 111 on the outer gear shaft 110 to achieve torque transmission. Stepped structures are provided on both sides of the second tooth 121 on the outer surface of the inner gear shaft 120. The left end and rear support 112 of the outer gear shaft 110 engage with the two stepped structures of the inner gear shaft 120, thus forming a mating front cylindrical surface Q and a rear cylindrical surface H. The outer gear shaft 110 and the inner gear shaft 120 are centered through the front cylindrical surface Q and the rear cylindrical surface H, and both the front cylindrical surface Q and the rear cylindrical surface H formed by the outer gear shaft 110 and the inner gear shaft 120 are interference fits with tightnesses of β and δ, respectively. The axial span between the front cylindrical surface Q and the rear cylindrical surface H is L.

[0029] The right end of the right stepped portion of the inner gear shaft 120 is provided with an axially extending tensioning portion 122. A limiting ring 160 is sleeved on the outside of the tensioning portion 122, with one end abutting against the rear support column 112 of the outer gear shaft 110, and the other end locked by an axial clamping nut 130. The tightening torque of the axial clamping nut 130 is M, which causes the outer gear shaft 110 to be axially positioned in the vertical plane S of the left stepped portion of the inner gear shaft 120.

[0030] The outer surface of the geared outer shaft 110 is provided with a radially extending limiting protrusion 113. The rear pivot bearing 150 is axially installed on the connection interface between the geared outer shaft 110 and the geared inner shaft 120, and is limited by the limiting protrusion 113.

[0031] The sleeve-tooth connection structure provided in this application, by placing the rear support bearing 150 at the connection interface between the outer sleeve-tooth shaft 110 and the inner sleeve-tooth shaft 120 near the bending mode node, allows the front support bearing (cold end) to bear a larger support constraint dynamic load in the high speed range of the compressor rotor, while reducing the dynamic load on the rear support bearing 150 which is in a higher ambient temperature, thereby facilitating the stable operation of the cantilever rotor system.

[0032] In the preferred embodiment of this application, the sleeve tooth connection structure is centered by the front cylindrical surface Q and the rear cylindrical surface H with an interference fit. Under the premise of meeting the strength requirements and the assemblability of the components, the tightness δ should be selected as large as possible according to relevant standards, and the dispersion between each part should be ensured to increase the initial assembly preload. This ensures that the front cylindrical surface Q and the rear cylindrical surface H of the sleeve tooth outer shaft 110 will not be circumferentially separated from the sleeve tooth inner shaft 120 during the working process, thereby reducing the stiffness loss of the sleeve tooth connection structure.

[0033] Furthermore, under the premise of meeting the strength requirements and the assemblability of the components, the tightening torque M of the axial clamping nut 130 should be selected as large as possible according to relevant standards, and the dispersion between each part should be ensured. The right step of the inner shaft 120 of the sleeve tooth is provided with an axially extended and thinner tensioning part 122 to form an elastic clamping part, which can reduce the axial tensile and compressive stiffness, increase the pre-deformation of the assembly, and reduce the stiffness loss of the sleeve tooth connection structure.

[0034] In this application, in order to control the slippage between the front cylindrical surface Q and the rear cylindrical surface H, and to avoid fatigue damage caused by interface contact stress and constraint damage caused by interface slippage, the axial span L between the front cylindrical surface Q and the rear cylindrical surface H can be set as large as possible within the limits of structural space. By increasing the axial span L between the front and rear centering surfaces to a certain extent, under the same bending load, the larger the span, the smaller the load burden borne by a single cylindrical contact surface, and thus the less likely interface slippage will occur.

[0035] In addition, this application also provides a cantilevered rotor system, which includes a compressor rotor and a turbine rotor 140. The turbine rotor 140 has a cantilevered turbine disk. The turbine rotor 140 and the compressor rotor are connected by the toothed connection structure 100 of this application. The front end of the compressor rotor is supported by a front pivot bearing, and the rear end of the compressor rotor is supported by a rear pivot bearing 150 in the toothed connection structure 100 of this application.

[0036] The sleeve-tooth connection structure and cantilever-supported rotor system provided in this application have the following advantages:

[0037] 1) It can reduce the stiffness loss of the sleeve tooth connection caused by bending load when the rotor is working at high speed, improve the interface constraint ability of the sleeve tooth connection structure, and improve the robustness.

[0038] 2) It can reduce the slippage of the sleeve tooth connection interface when the rotor is working at high speed, avoid fatigue damage and constraint damage at the contact interface, and improve robustness.

[0039] 3) By setting the sleeve tooth connection interface at the rear support bearing position, the stiffness of the sleeve tooth connection can be increased, the local deformation at the sleeve tooth connection can be reduced, and the centering interface can be guaranteed to have a good contact state, thereby reducing the axial slippage and interface deformation of the centering interface.

[0040] 4) By placing the axial position of the rear support bearing (hot end) close to the bending mode node, the front support bearing (cold end) bears a larger dynamic load of support constraint in the high speed range of the rotor, while the rear support bearing, which is in a higher ambient temperature, is subjected to a smaller dynamic load, which is beneficial to the stable operation of the rotor system.

[0041] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A toothed connection structure, characterized in that, The toothed connection structure (100) includes: A geared outer shaft (110) is fixedly connected to the turbine rotor (140). The outer surface of the geared outer shaft (110) away from the turbine rotor is provided with a limiting protrusion (113). The inner surface of the geared outer shaft (110) near the turbine rotor is provided with a rear support column (112). The inner surface of the geared outer shaft (110) is provided with a first tooth (111). The first tooth (111) is located between the rear support column (112) and the end. A geared inner shaft (120) is provided with a second tooth (121) on its outer surface to adapt to the first tooth (111). The outer surface of the geared inner shaft (120) is provided with a stepped structure on both sides of the second tooth (121). The end of the geared outer shaft (110) and the rear support (112) are respectively provided at the two stepped structures of the geared inner shaft (120) to form a mating front cylindrical surface and a rear cylindrical surface. The diameters of the front cylindrical surface, the outer surface of the geared inner shaft, and the rear cylindrical surface decrease in sequence. The geared inner shaft (120) has a tensioning part (122) extending toward the turbine rotor (140). A limiting ring (160) is provided on the outside of the tensioning part (122) of the inner shaft (120) of the sleeve gear, and the limiting ring (160) is abutted against the rear support (112) by an axial clamping nut (130); The rear pivot bearing (150) is mounted on the outer shaft (110) and located at the connection interface between the outer shaft (110) and the inner shaft (120). The rear pivot bearing (150) is axially limited by the limiting protrusion (113).

2. The toothed connection structure as described in claim 1, characterized in that, Both the front and rear cylindrical surfaces are interference fits.

3. The toothed connection structure as described in claim 1, characterized in that, The tightening torque of the axial clamping nut (130) is M, which causes the outer sleeve shaft (110) to be axially positioned on the vertical plane of the left step portion of the inner sleeve shaft (120).

4. The toothed connection structure as described in claim 1, characterized in that, The thickness of the tensioning part (122) is less than the thinnest position of the stepped structure of the inner shaft (120) of the sleeve, thereby making the tensioning part (122) an elastic structure.

5. A cantilevered rotor system, characterized in that, The cantilevered rotor system includes a compressor rotor and a turbine rotor, which are connected by a toothed connection structure as described in any one of claims 1 to 4.

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