A high-pressure compressor rotor disc rim axial assembly tolerance calculation method

Abstract

The application provides a high-pressure compressor rotor disc rim axial assembly tolerance calculation method, comprising the following steps: ① calculating centrifugal force component: calculating the centrifugal force axial component of the two end rotor discs; ② calculating rotor disc center shaft spacing: obtaining rotor stiffness, calculating the spacing between the center shafts of the rotor discs through the equation that the axial resultant force of the center wheel disc is zero; ③ calculating rotor disc rim axial gap: calculating the rotor disc rim axial gap through the spacing between the center shafts of the rotor discs; and ④ calculating axial assembly tolerance. The application can obtain the axial gap values of the rotor disc rims of each stage through numerical calculation to determine the axial assembly tolerance, so as to provide a design basis for determining the axial assembly tolerance of the rotor disc rims of each stage after the design improvement of the aero-engine high-pressure compressor rotor wheel disc, thereby effectively avoiding the above-mentioned blade fracture and engine stop working conditions in a low-cost manner.

Description

Technical Field

[0001] This invention relates to a method for calculating the axial assembly tolerance of a high-pressure compressor rotor disc rim. Background Technology

[0002] The high-pressure compressor is a core component of an aero-engine, and the assembly quality of its rotor directly affects the engine's performance. For example, in a certain type of engine, the first two stages of the high-pressure compressor are connected by short bolts, while the rear end face of the first-stage rotor is connected to the second through seventh-stage compressor discs, the front journal, the drum shaft, and the rear sealing grate disc by long bolts. Axial positioning between each stage disc is achieved using a stop-fit, and centering is achieved through cylindrical interference fits, with axial assembly tolerances of clearance or transition. The second-stage disc and the rear sealing grate disc's flanges are tilted forward and backward at certain angles, respectively, using the axial component of centrifugal force to press against each other, thus securing the flange edges connected by long bolts. Since the axial component of the centrifugal force from the second-stage disc and the rear sealing grate disc's flanges is transmitted to the center through each stage flange, if the axial components fail to cancel each other out when they reach the central disc (the "convergence point" of the axial components), it will cause axial displacement of the rotor discs, affecting the stable operation of the high-pressure compressor. When the positional displacement is too large, the engine will vibrate at high speeds, and in severe cases, blades may break, causing the engine to stop working.

[0003] After the high-pressure compressor is assembled, its internal structure is complex, making it difficult to directly calculate the internal tolerances. Considering cost, the ideal approach is to determine the axial assembly tolerances of each stage of the rotor disc rim based on numerical calculations during the design process. However, existing technologies do not provide an effective and usable solution for this, making it impossible to directly determine the axial assembly tolerances of each stage of the rotor disc rim through numerical calculations. This makes it difficult to effectively avoid the aforementioned blade breakage and engine shutdown in a low-cost manner. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for calculating the axial assembly tolerance of a high-pressure compressor rotor rim. This method can obtain the axial clearance of each stage of the rotor rim in an aero-engine high-pressure compressor through numerical calculation, providing a design basis for determining the axial assembly tolerance of each stage of the rotor rim after design improvements to the rotor disk of the aero-engine high-pressure compressor. This can effectively avoid the aforementioned blade breakage and engine shutdown in a low-cost manner.

[0005] The present invention is achieved through the following technical solutions.

[0006] This invention provides a method for calculating the axial assembly tolerance of a high-pressure compressor rotor rim, comprising the following steps: ① Calculate the centrifugal force components: Calculate the axial components of the centrifugal force of the rotor discs at both ends; ② Calculate the spacing between the central shafts of the rotor disks: Obtain the rotor stiffness and calculate the spacing between the central shafts of the rotor disks using the equation that the axial resultant force of the central disk is zero; ③ Calculate the axial clearance of the rotor disk rim: Calculate the axial clearance of the rotor disk rim by measuring the distance between the central shafts of the rotor disks; ④ Calculate axial assembly tolerance: Repeat steps ① to ③ above to calculate the rotor disc axial clearance at the minimum and maximum operating speeds, and then calculate the axial assembly tolerance from the rotor disc axial clearance.

[0007] Step ④ first calculates the rotor rim axial clearance at the lowest operating speed, and then repeats steps ① to ③ to calculate the rotor rim axial clearance at the maximum operating speed.

[0008] In step ②, it is assumed that the resultant force transmitted from the multi-stage rotor disks to the central disk is zero.

[0009] In step ①, the two rotor discs at both ends are the second-stage disc and the rear sealing grate toothed plate.

[0010] In step ②, it is assumed that the spacing between the central shafts of the rotor disks is equal.

[0011] In step ②, the stiffness is obtained through the design and finalization scheme of the high-pressure compressor rotor.

[0012] Step ③ is calculated using the following formula: in, The distance between the central shafts of the rotor discs. This refers to the axial component of the centrifugal force of the rear sealing grate tooth plate. This refers to the axial component of the centrifugal force of the second-stage disk. For the stiffness of the third-stage disk, For the stiffness of the fourth-level disk, For the stiffness of the sixth-level disk, The stiffness of the seventh-level disk.

[0013] The central shaft of the rotor disk is the fifth-stage disk.

[0014] The beneficial effects of this invention are as follows: the axial assembly tolerance of each stage of rotor disk edge can be determined by numerical calculation, so as to provide a design basis for determining the axial assembly tolerance of each stage of rotor disk edge after the design improvement of the high-pressure compressor rotor disk of aero-engine. In this way, the above-mentioned situation of blade breakage and engine stoppage can be effectively avoided in a low-cost manner. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating the present invention; Figure 2 yes Figure 1 A schematic diagram of one embodiment of the rotor disk; Figure 3 yes Figure 2 A schematic diagram of the force transmission path of the rotor disc; Figure 4 yes Figure 2 Schematic diagram for solving the axial clearance of the rotor. Detailed Implementation

[0016] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0017] Example 1 like Figure 1 The method for calculating the axial assembly tolerance of a high-pressure compressor rotor disc rim, as shown, includes the following steps: ① Calculate the centrifugal force components: Calculate the axial components of the centrifugal force of the rotor discs at both ends; ② Calculate the spacing between the central shafts of the rotor disks: Obtain the rotor stiffness and calculate the spacing between the central shafts of the rotor disks using the equation that the axial resultant force of the central disk is zero; ③ Calculate the axial clearance of the rotor disk rim: Calculate the axial clearance of the rotor disk rim by measuring the distance between the central shafts of the rotor disks; ④ Calculate axial assembly tolerance: Repeat steps ① to ③ above to calculate the rotor disc axial clearance at the minimum and maximum operating speeds, and then calculate the axial assembly tolerance from the rotor disc axial clearance.

[0018] Example 2 Based on Example 1, step ④ first calculates the axial clearance of the rotor disc rim under the lowest operating speed condition, and then repeats steps ① to ③ to calculate the axial clearance of the rotor disc rim under the maximum operating speed condition.

[0019] Example 3 Based on Example 1, in step ②, it is assumed that the resultant force transmitted from the multi-stage rotor disks to the central disk is zero.

[0020] Example 4 Based on Embodiment 1, in step ①, the two rotor discs at both ends are the second-stage disc and the rear sealing grate toothed plate.

[0021] Example 5 Based on Example 1, in step ②, it is assumed that the spacing between the central shafts of the rotor disks is equal.

[0022] Example 6 Based on Example 1, in step ②, the stiffness is obtained through the design and finalization scheme of the high-pressure compressor rotor.

[0023] Example 7 Based on Example 1, step ③ is calculated using the following formula: in, The distance between the central shafts of the rotor discs. This refers to the axial component of the centrifugal force of the rear sealing grate tooth plate. This refers to the axial component of the centrifugal force of the second-stage disk. For the stiffness of the third-stage disk, For the stiffness of the fourth-level disk, For the stiffness of the sixth-level disk, The stiffness of the seventh-level disk.

[0024] Example 8 Based on Embodiment 1, the central shaft of the rotor disk is a fifth-stage disk.

[0025] Example 9 Based on the above embodiments, the following steps are specifically adopted: 1) Calculate the axial components of the centrifugal force of the second-stage disc and the rear sealing grate under the lowest operating speed condition. F 2 and F h ; 2) Assume that the axial components of the second-stage disk and the rear sealing grate toothed plate are transmitted to the center through each stage of rotor disks, and the resultant force transmitted to the central disk is zero; 3) Assume the spacing between the central shafts of each stage of the rotor disc. x equal; 4) Since the stiffness E of each stage of the high-pressure compressor rotor is determined and known after the design is finalized, the distance between the central shafts of each stage rotor disk can be solved by the equation that the axial resultant force transmitted to the central disk is zero. x ; 5) Utilize the already solved spacing between the central shafts of each stage of the rotor disk x The value obtained by subtracting the rotor dimensions of each stage from this spacing is the axial clearance of the rotor disc rim for each stage. δ imin ; 6) Based on the maximum operating speed, repeat steps 1) to 5) above to calculate the axial clearance of each rotor disc rim at that speed. δ imax The axial assembly tolerance can be determined by the axial clearance of the rotor disc rims at both the lowest and maximum operating speeds.

[0026] Example 10 Based on the above embodiments, for example Figure 2 The calculations for the high-pressure compressor rotor disk shown are performed using the following specific steps: 1) Known parameters: mass m of each rotor stagei (kg), rotor stiffness E at each stage i (N / m), minimum operating speed n min (r / min), maximum operating speed n max (r / min), distance r from the center of gravity of each rotor stage to the axis of rotation i (m), second-stage disk tilt angle α2 (°), rear sealing grate disk width plate tilt angle α h (°). The subscript i indicates each stage of the rotor; 2) Based on the rotor mass m i (kg), minimum operating speed n min (r / min) and the distance from the center of gravity to the axis of rotation r i (m) Calculate the centrifugal force of the second-stage disc and the rear sealing grate plate. , Then the axial component of the second-stage disk... The axial component of the rear sealing grate toothed plate ; 3) Assuming the high-pressure compressor has seven rotor stages, its power transmission path diagram is as follows: Figure 3 As shown. The axial force transmitted from the second-stage disk to the third-stage rotor is... The axial force transmitted from the rear sealing grate tooth plate to the seventh-stage rotor is The same principle applies to all other levels; 4) Because the axial component of the centrifugal force of the second-stage disc and the rear sealing grate toothed plate is transmitted to the central rotor (the "convergence point" of the axial components—the fifth-stage rotor), it is necessary to ensure that the resultant axial force is 0. The axial clearance of each rotor stage can be calculated using this equation. ; 5) Since the axial clearance of each stage of the rotor is based on the centerline of each stage of the rotor, the axial clearance of the disk rims of adjacent stages of the rotor can be calculated based on the dimensions of the preceding and following stages of the rotor within this clearance. .by Figure 4 For example, the axial clearance between the rotor disk rims of the second and third stages. (in this equation) x , , (All of which are known), and so on, the axial clearances of the rotor disk rims of the other stages can be solved. δ imin ; 6) Based on the maximum operating speed n max Repeat steps 2) to 5) above to calculate the rotor rim clearance at each stage under this speed condition. δ imax The axial assembly tolerance of each rotor stage can be determined from the axial clearance of the rotor disc rims at the lowest and maximum operating speeds. δ imin ~ δ imax 。

Claims

1. A method for calculating the axial assembly tolerance of a high-pressure compressor rotor rim, characterized in that: Includes the following steps: ① Calculate the centrifugal force components: Calculate the axial components of the centrifugal force of the rotor discs at both ends; ② Calculate the spacing between the central shafts of the rotor disks: Obtain the rotor stiffness. Assuming that the spacing between the central shafts of the rotor disks is equal, calculate the spacing between the central shafts of the rotor disks using the equation that the axial resultant force of the central disk is zero. ③ Calculate the axial clearance of the rotor disk rim: Calculate the axial clearance of the rotor disk rim by measuring the distance between the central shafts of the rotor disks; ④ Calculate axial assembly tolerance: Repeat steps ① to ③ above to calculate the rotor disc axial clearance at the minimum and maximum operating speeds, and then calculate the axial assembly tolerance from the rotor disc axial clearance.

2. The method for calculating the axial assembly tolerance of the high-pressure compressor rotor flange as described in claim 1, characterized in that: Step ④ first calculates the rotor rim axial clearance at the lowest operating speed, and then repeats steps ① to ③ to calculate the rotor rim axial clearance at the maximum operating speed.

3. The method for calculating the axial assembly tolerance of the high-pressure compressor rotor flange as described in claim 1, characterized in that: In step ①, the two rotor discs at both ends are the second-stage disc and the rear sealing grate toothed plate.

4. The method for calculating the axial assembly tolerance of the high-pressure compressor rotor flange as described in claim 1, characterized in that: In step ②, the stiffness is obtained through the design and finalization scheme of the high-pressure compressor rotor.

5. The method for calculating the axial assembly tolerance of the high-pressure compressor rotor flange as described in claim 1, characterized in that: Step ③ is calculated using the following formula: in, The distance between the central shafts of the rotor discs. This refers to the axial component of the centrifugal force of the rear sealing grate tooth plate. This refers to the axial component of the centrifugal force of the second-stage disk. For the stiffness of the third-stage disk, For the stiffness of the fourth-level disk, For the stiffness of the sixth-level disk, The stiffness of the seventh-level disk.

6. The method for calculating the axial assembly tolerance of the high-pressure compressor rotor flange as described in claim 1, characterized in that: The central shaft of the rotor disk is the fifth-stage disk.

Images