Method for Selecting, Fitting and Replacing Engine Rotor Fasteners

Abstract

The present invention discloses a method for selecting and replacing fasteners of an engine rotor, which is used to screen out fasteners that match the original fasteners on the engine rotor from new fasteners. The method includes: a data collection step, a preliminary calculation step, a comparison calculation step, and a data output step. After the difference convergence in the data output step ends, a set of selected new fasteners is output. This selection and replacement method can compare the quality of fasteners and the mean value of fasteners in the same batch with the original fasteners from a large number of new fasteners, and quickly narrow down the range and screen out a specific number of fasteners that are relatively close to the original fasteners after multiple iterations and the convergence ends. For the fasteners screened by this method, before and after replacement, it is ensured that the static moment generated by the new fasteners is not much different from that of the old fasteners, which can avoid the influence of the unbalance amount generated by replacing the fasteners on the overall rotor and avoid the huge waste caused by rebalancing.

Description

Technical Field

[0001] The present invention relates to a method for selecting and replacing fasteners of an engine rotor. Background Art

[0002] During the development of an aeroengine, fasteners (such as bolts and nuts) of the engine rotor are involved. Due to reasons such as tests or product quality, it is necessary to replace the fasteners to meet the requirements of the new engine test performance. However, if a set of fasteners is randomly selected from a batch of fasteners to replace the fasteners on the original rotor mounting flange, it will have a great unbalance impact on the overall rotor. At this time, it is necessary to re-check the unbalance amount of the engine rotor and correct the unbalance amount so that the unbalance amount of the engine rotor is within the qualified range. This approach wastes a lot of time, and during the scientific research stage of the engine, the replacement of fasteners occurs frequently. If the replacement of fasteners occurs in the state of the whole machine assembly, the workload involved in the disassembly, reassembly, and rotor balancing of the whole machine will be extremely large. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defect of large workload when the fasteners of the engine rotor are replaced as a whole in the prior art, and provide a method for selecting and replacing fasteners of the engine rotor.

[0004] The present invention solves the above technical problem through the following technical solutions:

[0005] A method for selecting and replacing fasteners of an engine rotor, which is used to screen out fasteners that match the original fasteners on the engine rotor from new fasteners, and is characterized in that it includes:

[0006] Data collection step: Measure the mass of all the original fasteners on the engine rotor and the mass of all the new fasteners to be selected respectively, wherein the number of new fasteners is greater than the number of original fasteners;

[0007] Preliminary calculation step: Calculate the average value of the masses of all the original fasteners, and then calculate the difference between the mass of each original fastener and the average value of the original fasteners;

[0008] Comparison calculation step: Calculate the average value of the masses of all the new fasteners, and then calculate the difference between the mass of each new fastener and the average value of the new fasteners; Screen out the new fasteners with the differences closest to the differences of each original fastener from all the new fasteners, then calculate the average value of the masses of the selected new fasteners, and then calculate the difference between the masses of all the new fasteners and the average value of the selected new fasteners;

[0009] Data output step: Repeat the comparison calculation step until the difference in the average value of the masses is 0 and then end. After the difference converges and ends, output the set of the selected new fasteners.

[0010] The method for selecting and replacing the engine rotor fasteners can compare a large number of new fasteners with the original fasteners based on the quality of the fasteners and the mean value of the fasteners in the same batch, and quickly narrow down the range and screen out a specific number of fasteners that are relatively close to the original fasteners from a batch of new fasteners after multiple iterations and convergence.

[0011] Moreover, in the case of a large number of new fasteners (large sample data), the amount of calculation data only increases linearly for the above iterative calculation method, enabling the method for selecting and replacing the engine rotor fasteners to be applicable to selecting the fasteners that best match the original fasteners from a large number of new fasteners, so as to obtain the fasteners that match the original fasteners by increasing the number of new fasteners.

[0012] For the fasteners screened by this method, before and after replacement, it is ensured that the static torque generated by the new fasteners is not much different from that of the old fasteners, which can avoid the influence of the unbalance amount on the overall rotor caused by replacing the fasteners, and avoid the huge waste brought by rebalancing.

[0013] Preferably, in the data collection step, it further includes: obtaining the pitch circle diameter of each original fastener assembly;

[0014] After the data output step, it further includes a replacement and assembly step: calculating the static torque of the screened new fasteners and the static torque of the original fasteners according to the quality of the original fasteners, the quality of the screened new fasteners, and the pitch circle diameter of the assembly; reordering the set of the screened new fasteners so that the static torque of the reordered set of the screened new fasteners is closest to the static torque of the original fasteners, and replacing the original fasteners on the engine rotor with the screened new fasteners according to the sorting result.

[0015] For the method for selecting and replacing the engine rotor fasteners, after outputting the set of the screened new fasteners, calculate the static torque of each new fastener based on the pitch circle diameter of the original fastener assembly on the engine rotor, and sort according to the calculated static torque to obtain the best one-to-one correspondence between the screened new fasteners and the original fasteners, thereby obtaining a method for selecting and replacing the engine rotor fasteners based on the optimal static torque target, and further reducing the influence cost of the unbalance amount on the overall rotor caused by replacing the fasteners.

[0016] Preferably, in the data collection step, it further includes: numbering all the original fasteners and recording the corresponding numbers after measuring the quality of all the original fasteners; numbering all the new fasteners and recording the corresponding numbers after measuring the quality of all the new fasteners.

[0017] The method for selecting and replacing engine rotor fasteners facilitates the statistics and calculation of the original fasteners and new fasteners.

[0018] Preferably, in the data collection step, the number of new fasteners is more than twice the number of original fasteners.

[0019] The method for selecting and replacing engine rotor fasteners further improves the matching degree between the selected new fasteners and the original fasteners by increasing the number of new fasteners to be calculated.

[0020] A method for selecting and replacing engine rotor fasteners, which is used to select fasteners that match the original fasteners on the engine rotor from new fasteners, includes:

[0021] Data collection step: Obtain the pitch circle diameters of the assemblies of each original fastener, and respectively measure the masses of all the original fasteners on the engine rotor and the masses of all the new fasteners to be selected. Among them, the number of new fasteners is greater than the number of original fasteners;

[0022] Preliminary calculation step: Calculate the average value of the masses of all the original fasteners, and then calculate the difference between the mass of each original fastener and the average value of the original fasteners;

[0023] Comparison and calculation step: Calculate the average value of the masses of all the new fasteners, and then calculate the difference between the mass of each new fastener and the average value of the new fasteners; Select the new fasteners with the differences closest to the differences of each original fastener from all the new fasteners, then calculate the average value of the masses of the selected new fasteners, and then calculate the difference between the masses of all the new fasteners and the average value of the masses of the selected new fasteners; At the same time, calculate the static torque of the selected new fasteners and the static torque of the original fasteners according to the mass of the original fasteners, the mass of the selected new fasteners, and the pitch circle diameter of the assembly, and reorder the set of selected new fasteners so that the difference between the static torque of the reordered set of new fasteners and the static torque of the original fasteners in the original installation order is minimized;

[0024] Data output step: Repeat the comparison and calculation step until the average value of the mass is 0, and output the set of selected new fasteners after the difference converges.

[0025] The method for selecting and replacing engine rotor fasteners can compare the original fasteners with a large number of new fasteners based on the mass of the fasteners and the average value of the fasteners in the same batch, and quickly narrow down the range from a batch of new fasteners after multiple iterations and convergence, and select a preliminary set of new fasteners.

[0026] In addition, for the newly selected set of fasteners, it is also necessary to compare them with the old fasteners based on the static torque to verify the conclusion of the matching situation between the newly selected set of fasteners and the original fasteners, so as to more quickly narrow down the scope and obtain a specific number of fasteners that are relatively close to the original fasteners.

[0027] Moreover, in the case where the number of new fasteners is large (the sample data is large), the amount of calculated data only increases linearly with the above iterative calculation method. This enables the method for selecting and replacing the fasteners of the engine rotor to be applicable to selecting the fasteners that best match the original fasteners from a large number of new fasteners, so as to obtain the fasteners that match the original fasteners by increasing the number of new fasteners.

[0028] The fasteners screened by this method can ensure that the static torque generated by the new fasteners is not much different from that of the old fasteners before and after replacement, avoiding the influence of the imbalance caused by replacing the fasteners on the overall rotor and the huge waste brought by rebalancing.

[0029] Preferably, after the data output link, there is also a replacement and assembly link: calculate the static torque of the newly selected fasteners and the static torque of the original fasteners according to the mass of the original fasteners, the mass of the newly selected fasteners, and the pitch circle diameter of the assembly; reorder the set of newly selected fasteners so that the static torque of the reordered set of newly selected fasteners is closest to the static torque of the original fasteners, and replace the original fasteners on the engine rotor with the newly selected fasteners according to the sorting result.

[0030] After outputting the set of newly selected fasteners, the method for selecting and replacing the fasteners of the engine rotor calculates the static torque of each new fastener based on the pitch circle diameter of the assembly of the original fasteners on the engine rotor and sorts them according to the calculated static torque to obtain the best one-to-one correspondence between the newly selected fasteners and the original fasteners, thereby obtaining a method for selecting and replacing the fasteners of the engine rotor based on the optimal static torque target, further reducing the influence cost of the imbalance caused by replacing the fasteners on the overall rotor.

[0031] The positive and progressive effects of the present invention are as follows:

[0032] The method for selecting and replacing the fasteners of the engine rotor can compare the original fasteners with a large number of new fasteners based on the mass of the fasteners and the mean value of the fasteners in the same batch, and quickly narrow down the scope and screen out a specific number of fasteners that are relatively close to the original fasteners after multiple iterations and convergence.

[0033] Moreover, in this iterative calculation method, when the number of new fasteners is large, the amount of calculation data only increases linearly, enabling the method for selecting and replacing the fasteners of the engine rotor to be applicable to selecting the fastener that best matches the original fastener from a large number of new fasteners, so as to obtain, by increasing the number of new fasteners, the fastener that matches the original fastener.

[0034] The fasteners selected by this method can ensure that the static torque generated by the new fasteners is not much different from that of the old fasteners before and after replacement, avoiding the influence of the imbalance caused by replacing the fasteners on the overall rotor and the huge waste brought about by rebalancing. Brief Description of the Drawings

[0035] Figure 1 It is a schematic diagram of the method for selecting and replacing the fasteners of the engine rotor in Embodiment 1 of the present invention.

[0036] Figure 2 It is a schematic flow chart of the method for selecting and replacing the fasteners of the engine rotor in Embodiment 1 of the present invention. Detailed Embodiments

[0037] The present invention will be further described below by way of embodiments, but the present invention is not limited to the scope of the described embodiments.

[0038] Embodiment 1

[0039] The present invention provides a method for selecting and replacing the fasteners of an engine rotor, aiming to select the parts that match the original fasteners on the engine rotor from a batch of new fasteners to replace the original fasteners and reduce or avoid the influence of the imbalance caused by replacing the fasteners on the overall rotor. Among them, as Figure 1 shown, the original assembled fasteners are regarded as an ordered set B, and a batch of new fasteners (the number is greater than the original fasteners) are regarded as an ordered set A. The purpose of this method is to select new fasteners from set A to replace the original fasteners in set B. The flow of the method for selecting and replacing the fasteners of the engine rotor is as Figure 2 shown, and the specific implementation process is as follows:

[0040] The first step, the data collection link:

[0041] 1. Number all the original fasteners on the engine rotor according to the assembly order of the original fasteners.

[0042] 2. Weigh all the original fasteners with an electronic mass scale and record them together with the numbers.

[0043] 3. Number a batch of new fasteners. The number of new fasteners is at least twice or more than the number of the original assembled fasteners, and the more the better.

[0044] 4. Weigh this batch of new fasteners and record them together with their numbers.

[0045] 5. Obtain the pitch circle diameter d of each original fastener assembled on the engine rotor.

[0046] The second step, preliminary calculation link:

[0047] Put the mass m of the original fasteners i into an ordered set B according to their numbers, and obtain the average value of the masses of all elements in set B and label all the masses as the difference Δm from the average mass i , and the specific formula is as follows:

[0048]

[0049] In formula (1), is the average mass, and m i is the mass of the i-th number.

[0050] The third step, comparison and calculation link:

[0051] Put the mass M of the new fasteners i into an ordered set A according to their numbers, and obtain the average value of the masses of all elements in set A and label all the masses as the difference ΔM from the average mass i , and the specific formula is as follows:

[0052]

[0053] In formula (2), is the average mass of set A, and M i is the mass of the i-th number.

[0054] Among all the new fasteners in set A, screen out the batch of new fasteners whose difference ΔM i is closest to the difference Δm i of the original fasteners in set B to form set Mx i , and then calculate the average value of the masses of the screened new fasteners in set Mx i The specific formula is as follows: The specific formula is as follows:

[0055]

[0056] In formula (3), [] represents a set; and chose([x],y,z) means selecting the value closest to y from set x and adding this value to z.

[0057] Among them, the number of new fasteners in set Mx i is the same as the number of original fasteners.

[0058] Step 4, data output stage: Substitute the mean value calculated in the comparison and calculation stage into formula (2) to obtain the difference ΔM between each new fastener in the ordered set A and the new quality mean value . i .

[0059] Then substitute the recalculated difference ΔM i into formula (3) to reform a new set Mx i . Then calculate the mean value of the quality of the newly determined set Mx of new fasteners i . Substitute the mean value obtained from this calculation repeatedly into formula (2) and formula (3) until the mean value converges (i.e., the difference from the mean value in the previous calculation is 0), then the selection and matching of new fasteners are completed. At this time, output the set Mx of new fasteners obtained from the last calculation i .

[0060] Step 5, replacement and assembly stage: According to the mass m of the original fastener i , the mass M of the selected new fasteners i and the pitch circle diameter d of the assembly i calculate the static torque of the selected new fasteners and the static torque of the original fasteners, compare the static torque of the new fasteners with the static torque of the original fasteners, and obtain the preferred sorting order of the new fasteners. The specific formula is as follows:

[0061]

[0062] In formula (4), re - sort the set of selected new fasteners so that the static torque of the sorted set of fasteners installed on the engine rotor in sequence is closest to the static torque of the original fasteners installed on the engine rotor in sequence.

[0063] Finally, replace the original fasteners on the engine rotor with the sorted new fasteners in sequence.

[0064] This method for selecting and replacing fasteners of the engine rotor can compare the mass of fasteners and the mean value of fasteners in the same batch with the original fasteners from a large number of new fasteners, and quickly narrow down the range and screen out a specific number of fasteners that are relatively close to the original fasteners after multiple iterations and convergence.

[0065] Moreover, in the case where the number of new fasteners is relatively large (i.e., there is a large amount of data in the ordered set A), the overall amount of data calculated by this iterative calculation method only increases linearly, rather than exponentially. Therefore, the method for selecting and replacing the engine rotor fasteners can be applied to select the fastener that best matches the original fastener from a large number of new fasteners. Furthermore, by increasing the number of selectable new fasteners, it is possible to better select and obtain a fastener that more closely matches the original fastener from these new fasteners.

[0066] The fasteners screened by this method can ensure that the static torque generated by the new fasteners is not significantly different from that of the old fasteners before and after replacement, avoiding the impact of replacing the fasteners on the overall imbalance of the rotor and the huge waste caused by rebalancing.

[0067] The following takes a set of actual data as an example to illustrate the method for selecting and replacing the engine rotor fasteners provided by the invention. Among them, Table 1 and Table 2 respectively show the data of the original fasteners and the new fasteners for replacement:

[0068] Table 1 Data of the original fasteners

[0069]

[0070]

[0071] Table 2 Data of the new fasteners

[0072]

[0073]

[0074] In this embodiment, the pitch diameter d of the original fastener is 300. After calculation using the method for selecting and replacing the engine rotor fasteners provided by the present invention, the serial numbers selected from the new fasteners and the corresponding numbers of the old fasteners are shown in Table 3. The difference in the static torque of the set of new fasteners calculated is 0.6643 gmm compared to the original fastener, which can avoid the impact of replacing the fasteners on the overall imbalance of the rotor.

[0075] Table 3 Screening results of the new fasteners

[0076]

[0077] Example 2

[0078] This embodiment also provides a method for selecting and replacing engine rotor fasteners. The specific process of this method is generally the same as the method for selecting and replacing engine rotor fasteners provided in Embodiment 1. The difference is that in this embodiment, in the comparison and calculation step of the selection and replacement method, after obtaining the set Mx of new fasteners with the same quantity as the original fasteners based on formula (3) i it is also necessary to calculate the static moments of the selected new fasteners and the original fasteners according to the mass m of the original fasteners i , the mass M of the selected new fasteners i and the pitch circle diameter d of the assembly i . Then reorder the set of selected new fasteners to minimize the difference between the static moment of the reordered set of new fasteners and the static moment of the original fasteners in the original installation order. The specific formula is as follows:

[0079]

[0080] In formula (3.1), reorder the set of selected new fasteners so that the static moment of the reordered set of fasteners installed on the engine rotor in sequence is closest to (i.e., the difference is minimized) the static moment of the original fasteners installed on the engine rotor in sequence

[0081] In the comparison and calculation step of the method for selecting and replacing engine rotor fasteners provided in this embodiment, the set of new fasteners selected through formula (3) is also compared with the old fasteners based on the static moment to verify the matching situation between the set of selected new fasteners and the original fasteners, so as to more quickly narrow down the range and obtain a specific number of fasteners closer to the original fasteners

[0082] Although the specific implementation manners of the present invention have been described above, those skilled in the art should understand that this is only for illustration. The protection scope of the present invention is defined by the appended claims. Without departing from the principles and essence of the present invention, those skilled in the art can make various changes or modifications to these implementation manners, but these changes and modifications all fall within the protection scope of the present invention

Claims

1. A method for selecting and replacing fasteners of an engine rotor, which is used to screen out fasteners that match the original fasteners on the engine rotor from new fasteners, and is characterized in that, It includes: Data collection stage: Measure the mass of all original fasteners on the engine rotor and the mass of all new fasteners to be selected respectively. Among them, the number of new fasteners is greater than the number of original fasteners. Preliminary calculation stage: Calculate the average value of the mass of all original fasteners, and then calculate the difference between the mass of each original fastener and the average value of the original fasteners. Comparison calculation stage: Calculate the average value of the mass of all new fasteners, and then calculate the difference between the mass of each new fastener and the average value of the new fasteners; Screen out the new fasteners with the difference closest to the difference of each original fastener from all the new fasteners, then calculate the average value of the mass of the screened new fasteners, and then calculate the difference between the mass of all the new fasteners and the average value of the screened new fasteners. Data output stage: Repeat the above comparison calculation stage until the difference between the mass of the new fasteners and the average value of the screened new fasteners is 0 and then end. After the difference converges and ends, output the set of the screened new fasteners.

2. The method for selecting and replacing the engine rotor fastener according to claim 1, characterized in that, In the data collection stage, it also includes: Obtain the pitch circle diameter of each original fastener assembly. After the data output stage, it also includes a replacement and assembly stage: Calculate the static torque of the screened new fasteners and the static torque of the original fasteners according to the mass of the original fasteners, the mass of the screened new fasteners and the pitch circle diameter of the assembly; Reorder the set of the screened new fasteners so that the static torque of the reordered set of the screened new fasteners is closest to the static torque of the original fasteners, and replace the original fasteners on the engine rotor with the screened new fasteners according to the sorting result.

3. The method for selecting and replacing the engine rotor fastener according to claim 1, wherein In the data collection stage, it also includes: Number all the original fasteners, and record the corresponding numbers of the original fasteners after measuring the mass of all the original fasteners; Number all the new fasteners, and record the corresponding numbers of the new fasteners after measuring the mass of all the new fasteners.

4. The method for selecting and replacing the engine rotor fastener according to claim 1, characterized in that In the data collection stage, the number of new fasteners is more than twice the number of original fasteners.

5. A method for selecting and replacing engine rotor fasteners, which is used to screen out fasteners that match the original fasteners on the engine rotor from new fasteners, and is characterized in that, It includes: Data collection stage: Obtain the pitch circle diameter of each original fastener assembly, and measure the mass of all the original fasteners on the engine rotor and the mass of all the new fasteners to be selected respectively. Among them, the number of new fasteners is greater than the number of original fasteners. Preliminary calculation stage: Calculate the average value of the mass of all original fasteners, and then calculate the difference between the mass of each original fastener and the average value of the original fasteners. Comparison calculation stage: Calculate the average value of the mass of all new fasteners, and then calculate the difference between the mass of each new fastener and the average value of the new fasteners; Screen out the new fasteners with the difference closest to the difference of each original fastener from all the new fasteners, calculate the average value of the mass of the screened new fasteners, and then calculate the difference between the mass of all the new fasteners and the average value of the screened new fasteners; At the same time, calculate the static torque of the screened new fasteners and the static torque of the original fasteners according to the mass of the original fasteners, the mass of the screened new fasteners and the pitch circle diameter of the assembly, and reorder the set of the screened new fasteners so that the difference between the static torque of the reordered set of new fasteners and the static torque of the original fasteners in the original installation order is the smallest. Data output stage: Repeat the comparison and calculation stage until the difference between the mass of the new fasteners and the mean value of the selected new fasteners is 0, and end. After the difference converges and ends, output the set of selected new fasteners.

6. The method for selecting and replacing the engine rotor fastener according to claim 5, wherein After the data output stage, there is also a replacement and assembly stage: Calculate the static torque of the selected new fasteners and the static torque of the original fasteners according to the mass of the original fasteners, the mass of the selected new fasteners, and the pitch circle diameter of the assembly; Reorder the set of selected new fasteners so that the static torque of the reordered set of selected new fasteners is closest to the static torque of the original fasteners, and replace the original fasteners on the engine rotor with the selected new fasteners according to the sorting result.

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