A method for forward design of a squirrel-cage elastic support limiting gap

Abstract

This application belongs to the field of aero-engine structural design technology, and relates to a forward design method for the limiting clearance of a squirrel cage elastic support. The method includes: step S1, determining the maximum radial displacement generated at the squirrel cage spring support bearing seat based on the vibration limit value of the casing vibration measuring point; step S2, determining the vibration displacement generated at the squirrel cage spring support bearing seat based on the maneuvering overload; step S3, determining the initial value of the limiting clearance based on the maximum radial displacement and the vibration displacement; step S4, comparing the initial value of the limiting clearance with the oil film clearance of the squeeze oil film damper, and determining the final limiting clearance based on the comparison result. This application establishes a fast, accurate, and efficient forward design method and process for the limiting clearance of the squirrel cage spring support, improving design efficiency and ensuring reasonable structural design and engine operation safety.

Description

Technical Field

[0001] This application belongs to the field of aero-engine structural design technology, specifically relating to a positive design method for the elastic support limiting gap of a squirrel cage. Background Technology

[0002] In aero-engine dynamics design, the squirrel-cage spring support-squeezed oil film damper is the most commonly used structure for optimizing overall engine vibration characteristics. Combined with the squeezed oil film damper design, it can provide additional damping to suppress vibration. The squirrel-cage spring support is an elastic structure with relatively weak stiffness. When the rotor system experiences significant vibration or the aircraft performs maneuvers, to prevent the squirrel-cage spring support from undergoing large deformations and causing destructive failures, a squirrel-cage spring support limiter is usually designed to restrict the radial displacement of the bearing housing end. Simultaneously, the limiter clearance must be designed reasonably, avoiding excessively large or small clearances that could affect engine safety and rotor system vibration response. Based on this background, the limiter clearance design needs to be carried out simultaneously during the spring support design. Currently, the squirrel-cage spring support limiter clearance is mostly determined using empirical values ​​or the oil film clearance of the squeezed oil film damper. Existing methods for determining the limiter clearance have the following drawbacks:

[0003] 1. When designing the limit gap of the spring support of a new size squirrel cage, the empirical method cannot quickly give a reasonable limit gap value. It usually requires multiple rounds of strength evaluation to determine the value, which is a lot of work.

[0004] 2. If the displacement of the squirrel cage spring support under conditions of large vibration or motor overload cannot be determined, and the oil film design gap of the extrusion oil film damper is directly used as the limiting gap of the squirrel cage spring support, it will directly affect the oil film uniformity and operating status of the extrusion oil film damper, and greatly sacrifice the vibration reduction characteristics of the extrusion oil film damper.

[0005] 3. It is impossible to carry out positive design of the squirrel cage spring support limit gap based on the rotor system and engine operating status, which easily increases the design workload and uncertainty. Summary of the Invention

[0006] To address the aforementioned problems, this application provides a positive design method for the elastic support limiting gap of a squirrel cage, mainly comprising:

[0007] Step S1: Determine the maximum radial displacement generated at the squirrel cage spring support bearing seat based on the vibration limit value of the casing vibration measuring point;

[0008] Step S2: Determine the vibration displacement generated at the squirrel cage spring support bearing seat based on the motor overload.

[0009] Step S3: Determine the initial value of the limiting gap based on the maximum radial displacement and vibration displacement;

[0010] Step S4: Compare the initial value of the limiting gap with the oil film gap of the extrusion oil film damper, and determine the final limiting gap based on the comparison result.

[0011] Preferably, in step S1, the maximum radial displacement generated at the squirrel cage spring support bearing seat is determined by the following formula. :

[0012] ;

[0013] in, This represents the vibration limit value at the casing vibration measuring point. For rotor speed, The signal transmission attenuation coefficient is the signal transmitted from the squirrel cage spring bearing seat to the vibration measuring point of the casing.

[0014] Preferably, in step S2, the vibration displacement generated at the squirrel cage spring support bearing seat is determined by the following formula. :

[0015] ;

[0016] in, For motor overload capacity, The load on the support point of the projectile under unit maneuver overload. This refers to the support stiffness of the squirrel cage spring bearing housing.

[0017] Preferably, step S4 further includes:

[0018] When the initial value of the limiting gap is lower than the oil film gap of the extrusion oil film damper, an independent limiting device is set on one side of the extrusion oil film damper, and the limiting gap between the limiting device and the squirrel cage spring support bearing seat is set as the initial value of the limiting gap. Otherwise, no independent limiting device is set, and the oil film gap of the extrusion oil film damper is directly used as the final limiting gap.

[0019] A second aspect of this application provides a computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the positive design method for the elastic support limiting gap of the mouse cage as described above.

[0020] A third aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor, when executing the program, implements the positive design method for the elastic support limiting gap of the mouse cage as described above.

[0021] This application takes into account the reasonable design of the oil film clearance of the squeeze oil film damper and the limiting clearance of the squirrel cage spring support, and forms a fast, accurate and efficient forward design method and process for the limiting clearance of the squirrel cage spring support, which improves design efficiency and ensures reasonable structural design and safe use of the engine. Attached Figure Description

[0022] Figure 1 This is a flowchart of a preferred embodiment of the positive design method for the elastic support limiting gap of the rat cage in this application.

[0023] Figure 2 This application Figure 1 A schematic diagram of the elastic support structure of the squirrel cage with a squeeze oil film damper and a limiter in the embodiment shown.

[0024] Among them, 1-shaft section, 2-bearing, 3-bearing housing, 4-squirrel cage spring support, 5-extrusion oil film damper, 6-oil film gap, 7-limiting gap, 8-limiter. Detailed Implementation

[0025] 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. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0026] This application provides a positive design method for the elastic support limiting gap of a mouse cage, such as... Figure 1 As shown, it mainly includes:

[0027] Step S1: Determine the maximum radial displacement generated at the squirrel cage spring support bearing seat based on the vibration limit value of the casing vibration measuring point;

[0028] Step S2: Determine the vibration displacement generated at the squirrel cage spring support bearing seat based on the motor overload.

[0029] Step S3: Determine the initial value of the limiting gap based on the maximum radial displacement and vibration displacement;

[0030] Step S4: Compare the initial value of the limiting gap with the oil film gap of the extrusion oil film damper, and determine the final limiting gap based on the comparison result.

[0031] This application establishes a forward design method and process for the limiting gap of a squirrel cage spring support. It comprehensively considers the impact of rotor system vibration response and motor overload during the use of the squirrel cage spring support, and also considers the rationality of the oil film gap design of the extrusion oil film damper, thus completing the forward design of the limiting gap of the squirrel cage spring support.

[0032] The initial value of the limiting gap in this application consists of two parts: the maximum radial displacement calculated by step S1, and the vibration displacement calculated by step S2.

[0033] Vibration displacement generated at the spring support bearing housing due to shaft vibration The vibration velocity generated at the spring bearing seat can be expressed as equation (1). It can be expressed as equation (2):

[0034] (1)

[0035] (2)

[0036] in The amplitude of the vibration displacement. For rotor speed, For time, For phase.

[0037] Accordingly, in step S1 of this application, the vibration limit value of the known casing vibration measuring point can be used. Combined with the signal transmission attenuation coefficient from the bearing to the vibration measuring point of the casing, The maximum radial displacement at the squirrel cage spring bearing housing caused by rotor system vibration is calculated. Specifically, in some optional embodiments, in step S1, the maximum radial displacement at the squirrel cage spring bearing housing is determined by the following formula. :

[0038] ;

[0039] in, This represents the vibration limit value at the casing vibration measuring point. For rotor speed, The signal transmission attenuation coefficient is the signal transmitted from the squirrel cage spring bearing seat to the vibration measuring point of the casing.

[0040] Furthermore, in step S2, the maneuvering overload caused by common flight maneuvers of the engine in its installed state is analyzed, and combined with the results of the dynamic load analysis of the pivot point, the vibration displacement generated by the bearing mounting is determined, that is, the maximum permissible displacement of the squirrel cage missile support bearing housing caused by the maneuvering overload is determined. For example, in some optional embodiments, in step S2, the vibration displacement generated at the squirrel cage missile support bearing housing is determined by the following formula. :

[0041] ;

[0042] in, For motor overload capacity, The load on the projectile support point under a unit motor overload (1g) is the load on the projectile support point. This refers to the support stiffness of the squirrel cage spring bearing housing.

[0043] In step S3, the initial value of the limiting gap is calculated. :

[0044] .

[0045] Step S4 is used to determine the final limiting gap based on the initial value of the limiting gap and the oil film gap of the extrusion oil film damper. In some optional embodiments, step S4 further includes:

[0046] When the initial value of the limiting gap is lower than the oil film gap of the extrusion oil film damper, an independent limiting device is set on one side of the extrusion oil film damper, and the limiting gap between the limiting device and the squirrel cage spring support bearing seat is set as the initial value of the limiting gap. Otherwise, no independent limiting device is set, and the oil film gap of the extrusion oil film damper is directly used as the final limiting gap.

[0047] In this embodiment, the system with the added limiter is as follows: Figure 2 As shown, the system mainly includes a rotating shaft (shaft segment 1), bearing 2, squirrel cage spring support 4, extrusion oil film damper 5, and limiter 8.

[0048] The squirrel cage spring support 4, the extrusion oil film damper 5, and the limiter 8 are respectively fixed on the stator housing. A bearing seat 3 is provided at the cantilever end of the squirrel cage spring support 4, and the shaft section 1 is connected via a bearing 2. An oil film gap 6 is formed between the extrusion oil film damper 5 and the bearing seat 3, and a limiting gap 7 is formed between the limiter 8 and the bearing seat 3. Based on the comparison of the oil film gap of the extrusion oil film damper... Initial value of the limit gap Determine the final limit gap based on the size. :

[0049] ;

[0050] That is, when the initial value of the limit gap is calculated Oil film gap below the squeezing oil film damper When using a limit switch, a separate limit switch is set, and the limit gap is [missing information]. When the initial value of the limit gap is calculated Low to high oil film gap of the extrusion oil film damper At this time, the oil film gap of the extrusion oil film damper is taken as the limiting gap, and no separate limiter is set.

[0051] A second aspect of this application provides a computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the positive design method for the elastic support limiting gap of the mouse cage as described above.

[0052] A third aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor, when executing the program, implements the positive design method for the elastic support limiting gap of the mouse cage as described above.

[0053] This application comprehensively considers the impact of rotor system vibration response and motor overload during the use of the squirrel cage spring support, ensuring that the design of the squirrel cage spring support limiting clearance and the design of the oil film clearance of the extrusion oil film damper are both in their most reasonable state. A method for calculating and determining the squirrel cage spring support limiting clearance is established, taking into account the reasonable design of the oil film clearance of the extrusion oil film damper and the squirrel cage spring support limiting clearance. A fast, accurate and efficient forward design method and process for the squirrel cage spring support limiting clearance is formed, which improves design efficiency, ensures reasonable structural design, and ensures engine safety.

[0054] 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 method for positive design of elastic support limiting gap in a rat cage, characterized in that, include: Step S1: Determine the maximum radial displacement generated at the squirrel cage spring support bearing seat based on the vibration limit value of the casing vibration measuring point; Step S2: Determine the vibration displacement generated at the squirrel cage spring support bearing seat based on the motor overload. Step S3: Determine the initial value of the limiting gap based on the maximum radial displacement and vibration displacement; Step S4: Compare the initial value of the limiting gap with the oil film gap of the extrusion oil film damper, and determine the final limiting gap based on the comparison result.

2. The positive design method for the elastic support limiting gap of the rat cage according to claim 1, characterized in that, In step S1, the maximum radial displacement generated at the squirrel cage spring support bearing seat is determined by the following formula. : ； in, This represents the vibration limit value at the casing vibration measuring point. For rotor speed, The signal transmission attenuation coefficient is the signal transmitted from the squirrel cage spring bearing seat to the vibration measuring point of the casing.

3. The positive design method for the elastic support limiting gap of the rat cage according to claim 1, characterized in that, In step S2, the vibration displacement generated at the squirrel cage spring support bearing seat is determined by the following formula. : ； in, For motor overload capacity, The load on the support point of the projectile under unit maneuver overload. This refers to the support stiffness of the squirrel cage spring bearing housing.

4. The positive design method for the elastic support limiting gap of the rat cage according to claim 1, characterized in that, Step S4 further includes: When the initial value of the limiting gap is lower than the oil film gap of the extrusion oil film damper, an independent limiting device is set on one side of the extrusion oil film damper, and the limiting gap between the limiting device and the squirrel cage spring support bearing seat is set as the initial value of the limiting gap. Otherwise, no independent limiting device is set, and the oil film gap of the extrusion oil film damper is directly used as the final limiting gap.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the positive design method for the elastic support limiting gap of the mouse cage as described in any one of claims 1 to 4.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the positive design method for the elastic support limiting gap of the mouse cage as described in any one of claims 1 to 4.

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