A method for determining gear tooth surface pitting damage for a locomotive

Abstract

This invention provides a method for judging pitting damage on the tooth surface of locomotive gears. The proposed method involves creating two simulated panels corresponding to the tooth surface to be inspected. Critical values ​​for two pitting states are simulated on the two panels, and the pitting area is compared to visually determine whether it meets standard requirements. This method significantly improves production efficiency while ensuring the quality of gear repair. This invention can greatly improve the quality and efficiency of locomotive gear repair, enabling enterprises to reduce costs and increase efficiency.

Description

Technical Field

[0001] This invention relates to rail locomotive maintenance technology, and more particularly to rail locomotive gear inspection technology, specifically a method for determining pitting damage on the tooth surface of locomotive gears. Background Technology

[0002] After railway locomotives enter a major overhaul, especially after two or more overhauls, the gear surfaces generally exhibit varying degrees of pitting. Pitting is a fatigue phenomenon on gear tooth surfaces in rolling contact or mixed rolling and sliding contact, where granular flaking from the damaged surface results in scattered pits on the tooth surface. According to national railway enterprise standards, when railway locomotives enter a major overhaul, the pitting area on the gear tooth surface must not exceed 15%; exceeding 15% indicates failure. If the pitting damage further develops, it will lead to tooth surface peeling. The standard stipulates that the area of ​​single peeled tooth surface on locomotive gears during major overhauls should not exceed 6mm. 2 .

[0003] Since pitting corrosion on tooth surfaces typically presents as scattered, pitted spots, the current method for identifying this pattern relies solely on manual inspection. The specific process involves using a ruler to measure the size of each pit, calculating its area, and finally determining the total pitting area. While accurate, this method is extremely slow. Given the large number of gears on a locomotive, this inspection method significantly impacts the quality and efficiency of gear maintenance. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for judging pitting damage on the tooth surface of locomotive gears. This method uses two simulated pitting panels to determine the pitting condition of locomotive gears. This method is intuitive, efficient, and its testing standards meet the requirements of national railway standards, improving the quality and efficiency of gear maintenance and providing better safety assurance for rail transportation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for determining pitting damage on the tooth surface of locomotive gears includes the following steps:

[0007] Step 1: Fabricate simulation panels A and B, both of which are the same size as the tooth surface to be inspected. Multiple pitting etchings A are created on simulation panel A, with the total area of ​​the pitting etchings A equal to 15% of the area of ​​simulation panel A. The diameter D of each individual pitting etching A is... A The diameter is 0.8–1.2 mm; multiple pitted etchings B are created on the simulation panel B, the total area of ​​the multiple pitted etchings B is equal to 15% of the area of ​​the simulation panel B, and the diameter D of a single pitted etching B is... B It is 2.4–2.7 mm;

[0008] The second step is to set the diameter on the tooth surface to be inspected to be less than or equal to D. A The pitting is small pitting, with a diameter greater than D. A And less than or equal to D B The pitting is large pitting;

[0009] The third step is to compare the simulated panel B with the tooth surface to be inspected. If the area of ​​a single pitting corrosion on the tooth surface to be inspected is larger than the area of ​​a single pitting corrosion B, it is judged as tooth surface peeling, which is unqualified; otherwise, proceed to the fourth step.

[0010] Step 4: Compare the simulated panel B with the tooth surface to be inspected. If the number of large pits on the tooth surface to be inspected is greater than or equal to the number of pits B, the tooth surface pitting damage is deemed unacceptable; otherwise, proceed to step 5.

[0011] Step 5: Compare the simulated panel B with the tooth surface to be inspected. If the number of large pits on the tooth surface to be inspected is less than the number of pits B, record the number and calculate the total area S of all large pits. 大 Then proceed to step six;

[0012] Step 6: Compare the simulated panel A with the tooth surface to be inspected and record the number of small pits. If the total number of pits on the tooth surface to be inspected is greater than or equal to the number of pits in panel A, the pitting damage on the tooth surface to be inspected is unacceptable and cannot be used. If the total number of pits on the tooth surface to be inspected is less than the number of pits in panel A, calculate the total area S of all small pits. 小 If S 大 With S 小 If the sum of the pitting corrosion areas does not exceed 15% of the area of ​​the tooth surface to be inspected, then the pitting corrosion is acceptable; otherwise, it is unacceptable.

[0013] Both pitting A and pitting B are through holes, and the diameter D of pitting A is... A The diameter D of pitting B is 1 mm. B It is 2.6 mm.

[0014] The beneficial effects of this invention are as follows: The judgment method proposed in this invention involves creating two simulated panels corresponding to the tooth surface to be inspected. The critical values ​​for two pitting corrosion states are simulated on the two panels respectively. By comparing the values, it is possible to intuitively determine whether the pitting area of ​​the gear meets the standard requirements. This method greatly improves production efficiency while ensuring the quality of gear maintenance. This invention can significantly improve the quality and efficiency of locomotive gear maintenance, enabling enterprises to reduce costs and increase efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the simulated panel A in Example 1.

[0016] Figure 2 This is a schematic diagram of the simulation panel B in Example 1. Detailed Implementation

[0017] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1: The tooth surface of a certain type of gear is a rectangle of 20x100mm. According to the national railway standard, the pitting area on its tooth surface cannot exceed 15%, and the tooth surface cannot have peeling (i.e., an area of ​​6mm). 2 The above-mentioned pitting damage is now being assessed using the method proposed in this invention. The specific steps are as follows:

[0019] Step 1: Fabricate simulation panels A and B. Simulation panels A and B are the same size as the tooth surface to be inspected, i.e., both are rectangular plates of 20x100 mm. Multiple evenly distributed pits A are machined on simulation panel A. Since the total area of ​​the multiple pits A is equal to 15% of the area of ​​simulation panel A, the diameter D of a single pit A is preferably [missing information]. A If the diameter is 1 mm, then the number of pits A is 382.16, which can be rounded down to 383. Multiple evenly distributed pits B are processed on the simulated panel B. Since the total area of ​​the multiple pits B is equal to 15% of the area of ​​the simulated panel B, the preferred diameter D of a single pit B is... B If the diameter is 2.6 mm, then the number of pitting B erosions is 56.6, which is rounded up to 57.

[0020] The second step is to set the diameter on the tooth surface to be inspected to be less than or equal to D. A The pitting is small pitting, with a diameter greater than D. A And less than or equal to D B The pitting is large pitting;

[0021] The third step is to use the simulation panel B to perform a close comparison with the tooth surface to be inspected. If the area of ​​a single pitting corrosion on the tooth surface to be inspected is larger than the area of ​​a single pitting corrosion B, i.e., 5.3 mm... 2 If the tooth surface is peeled off, it is considered unqualified; otherwise, proceed to step four.

[0022] Step 4: Still use the simulation panel B to closely compare with the tooth surface to be inspected. If the number of large pits on the tooth surface to be inspected is greater than or equal to the number of pits B, the tooth surface pitting damage is judged to be unqualified; otherwise, proceed to step 5.

[0023] Step 5: Using the simulation panel B, perform a close comparison with the tooth surface to be inspected. If the number of large pits on the tooth surface to be inspected is less than the number of pits B, record the number and calculate the total area S of all large pits.大 Then proceed to step six;

[0024] Step 6: Use simulation panel A to closely compare the surface of the tooth to be inspected, and record the number of small pits. If the total number of pits on the surface to be inspected is greater than or equal to the number of pits in panel A, the pitting damage on the surface to be inspected is unacceptable and cannot be used. If the total number of pits on the surface to be inspected is less than the number of pits in panel A, calculate the total area S of all small pits. 小 If S 大 With S 小 If the sum of the pitting corrosion areas does not exceed 15% of the area of ​​the tooth surface to be inspected, then the pitting corrosion is acceptable; otherwise, it is unacceptable.

[0025] Both pitting A and pitting B are through holes. Pitting A was chosen with a diameter of 1 mm for ease of calculation and observation; pitting B was chosen with a diameter of 2.6 mm, with an area of ​​5.3 mm². 2 This corresponds to the criterion for peeling, which is that the area of ​​a single pitting corrosion is no greater than 6mm. 2 The value chosen here is slightly smaller than the stripping criterion, mainly to prevent misjudgment during visual inspection.

[0026] It should be noted that in reality, the shape of most pitting on gears is approximately circular, but there are also irregularly shaped pitting. When comparing, the area of ​​irregularly shaped pitting can be calculated and included in the total area of ​​pitting on the tooth surface.

[0027] The principle of the invention is explained below with reference to Example 1: The invention first uses a simulation panel to determine two extreme cases. Gear pitting can be large or small, with scattered pitting being the most common. In Example 1, simulation panels A and B already cover both large and small pitting. In special cases, the size of a single pitting area is determined by the standard for peeling, with a single area not exceeding 6mm. 2 This represents another extreme case. In Example 1, the diameter of a single pit is set at 2.6 mm, which is both for cases with a large pit area and covers the criteria for peeling. After the two extreme cases are determined, most pit states can usually be identified. The remaining cases belong to the third case, that is, pits of varying sizes, which can also be identified according to the present invention.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0029] The parts of this invention not described in detail are prior art.

Claims

1. A method for determining pitting damage on the tooth surface of locomotive gears, characterized in that: Includes the following steps: Step 1: Fabricate simulation panels A and B, both of which are the same size as the tooth surface to be inspected. Multiple pitting etchings A are created on simulation panel A, with the total area of ​​the pitting etchings A equal to 15% of the area of ​​simulation panel A. The diameter D of each individual pitting etching A is... A The diameter is 0.8–1.2 mm; multiple pitted etchings B are created on the simulation panel B, the total area of ​​the multiple pitted etchings B is equal to 15% of the area of ​​the simulation panel B, and the diameter D of a single pitted etching B is... B It is 2.4–2.7 mm; The second step is to set the diameter on the tooth surface to be inspected to be less than or equal to D. A The pitting is small pitting, with a diameter greater than D. A And less than or equal to D B The pitting is large pitting; The third step is to compare the simulated panel B with the tooth surface to be inspected. If the area of ​​a single pitting corrosion on the tooth surface to be inspected is larger than the area of ​​a single pitting corrosion B, it is judged as tooth surface peeling, which is unqualified; otherwise, proceed to the fourth step. Step 4: Compare the simulated panel B with the tooth surface to be inspected. If the number of large pits on the tooth surface to be inspected is greater than or equal to the number of pits B, the tooth surface pitting damage is deemed unacceptable; otherwise, proceed to step 5. Step 5: Compare the simulated panel B with the tooth surface to be inspected. If the number of large pits on the tooth surface to be inspected is less than the number of pits B, record the number and calculate the total area S of all large pits. 大 Then proceed to step six; Step 6: Compare the simulated panel A with the tooth surface to be inspected and record the number of small pits. If the total number of pits on the tooth surface to be inspected is greater than or equal to the number of pits in panel A, the pitting damage on the tooth surface to be inspected is unacceptable and cannot be used. If the total number of pits on the tooth surface to be inspected is less than the number of pits in panel A, calculate the total area S of all small pits. 小 If S 大 With S 小 If the total area of ​​pitting does not exceed 15% of the area of ​​the tooth surface to be inspected, then the pitting is acceptable; otherwise, it is unacceptable.

2. The method for determining pitting damage on the tooth surface of locomotive gears according to claim 1, characterized in that: Both pitting A and pitting B are through holes, and the diameter D of pitting A is... A The diameter D of pitting B is 1 mm. B It is 2.6 mm.

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