A grinding repair method for a central drive spline shaft

Abstract

This invention relates to a grinding repair method for a central drive spline shaft, belonging to the field of repair technology. The invention proposes a grinding repair method for a central drive spline shaft. This method involves micro-grinding of the splines on a drive shaft with out-of-tolerance tooth direction but whose spline tooth thickness meets process requirements and has a significant remaining lifespan. This restores the technical condition of the spline teeth on the central drive spline shaft to its original process level, extends the lifespan guarantee capability of the drive shaft, and achieves cost reduction and efficiency improvement.

Description

Technical Field

[0001] This invention relates to the field of repair technology, and specifically to a grinding repair method for a central drive spline shaft. Background Technology

[0002] The central drive spline shaft is installed inside the accessory drive mechanism of a certain type of engine and is a key component of this mechanism. Both ends of the shaft are equipped with splines. The process specifications stipulate that the tooth deviation of a new product should not exceed 0.01mm, and after one overhaul interval, the tooth deviation should not exceed 0.014mm. Due to the impact during startup and cumulative wear during use, the spline surface can become adhered and worn. Therefore, after one overhaul interval, most central drive shafts exhibit tooth deviation exceeding the tolerance. The spline shaft's addendum circle is Ф13.5mm, the dedendum circle is Ф11.5mm, the total tooth height is only 1mm, and the pitch circle groove width is approximately 1.25mm. Due to the small size, and considering that the repair allowance is typically between 0.010mm and 0.015mm, the repair allowance is extremely small. Traditional form grinding and tool setting processes are difficult to observe, and the tool setting process may directly lead to over-grinding and product scrap. For a long time, replacement of parts has been the solution in repairs. Summary of the Invention

[0003] To address the aforementioned technical problems, the purpose of this invention is to provide a grinding repair method for a central drive spline shaft. This invention performs micro-grinding on a central drive spline shaft with out-of-tolerance tooth direction but whose spline tooth thickness meets process requirements and has a relatively large remaining lifespan. This restores the technical condition of the spline teeth of the central drive spline shaft to its original process level, expands the full lifespan guarantee capability of the drive shaft, and achieves cost reduction and efficiency improvement.

[0004] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: The purpose of this invention is to provide a grinding repair method for a central drive spline shaft, the specific steps of which are as follows: (1) Adjust the spline grinding machine and brush a mark on the surface of the involute spline to be ground on the central drive spline shaft; install the central drive spline shaft on both sides of the spline grinding machine, adjust the forming grinding wheel into the tooth groove of the involute spline to be ground, until the grinding wheel contacts the spline, feel the tightness up, down, left and right, so that the resistance of the grinding wheel and the spline is 1N·m-2N·m; (2) Determine the positions of the Z-axis and A-axis of the spline grinder, retract the tool from the direction of the Z-axis, and gradually feed from the Z-axis until the forming grinding wheel contacts one side of the spline tooth of the involute spline to be ground. The Z-axis dimension is related to the diameter of the grinding wheel and the diameter of the workpiece. Record the Z-axis dimension at this time. When the subsequent feed approaches the Z-axis dimension, the feed speed should be reduced, and the contact between the grinding wheel and the workpiece should be observed to avoid collision between the grinding wheel and the workpiece during feed. Deflect the A-axis so that the other side of the spline tooth also contacts the tool. Record the A-axis dimension at this time, and retract the A-axis to ensure that the grinding wheel is in the center position. (3) Fine-tune the Z-axis micro-feed again, feed 4μm~6μm per cut, so that the involute spline to be ground touches the tool again, deflect the A-axis to perform micro-grinding on the worn side of the involute spline to be ground, feed 0.01°~0.03° per cut, then perform non-destructive testing, and finally perform dynamic balancing according to the drawing requirements of the central drive spline shaft.

[0005] The beneficial effects of this invention are as follows: This invention provides a method for micro-grinding repair of a central drive spline shaft. Its core lies in addressing the problem of excessive tooth direction tolerance in the central drive spline shaft. First, based on spline parameters such as tooth thickness allowance, repairable parts are selected. Then, through precision tool setting, the grinding wheel is positioned in the center of the tooth groove, combined with a micro-feed by A-axis deflection, to precisely grind away the adhesive protrusions on the worn side of the spline. Finally, through inspection, flaw detection, and dynamic balancing verification, the transmission performance of the central drive spline shaft is restored. This achieves high-precision, controllable, and consistent repair of the spline drive shaft, solving the problem of excessive tooth direction tolerance caused by adhesive wear.

[0006] (1) It completely solves the problem of tooth direction deviation caused by the adhesion and wear of involute splines. The repaired involute spline pair has good contact and smooth transmission. It fundamentally eliminates the acceleration of involute spline wear and improves the transmission reliability of engine accessories.

[0007] (2) The spline shafts that were originally scrapped due to tooth direction deviation but still had remaining life were restored to performance and used again, saving the cost of purchasing new products and achieving cost reduction and efficiency improvement.

[0008] (3) The traditional “craft” that relies on workers’ experience has been transformed into a standardized and replicable process, which solves the problem of repair consistency and provides a valuable technical model for the repair of similar precision parts.

[0009] Based on the above technical solution, the present invention can be further improved as follows.

[0010] Furthermore, in step (2), the maximum grinding allowance L on one side of the involute spline to be ground is... max Greater than or equal to the grinding amount ΔL; The maximum grinding allowance L max The calculation method is as follows: L max=S-(S min +Fr / 2); The grinding amount △L is calculated as follows: △L=F β实max -F β规max ; Where S is the actual pitch arc tooth thickness of the involute spline to be ground; S min The minimum pitch radius tooth thickness is required by the drawing of the involute spline to be ground; Fr is the actual tooth ring runout of the involute spline to be ground; the F... β实max F represents the maximum tooth direction value of the involute spline to be ground; β规max The maximum value of the specified tooth direction of the involute spline to be ground is given by L. max Repair can only be carried out if the value is ≥△L and the repair conditions are met; otherwise, the item must be scrapped.

[0011] The beneficial effects of adopting the above-mentioned further solutions are: the entire repair process is based on measured data such as spline tooth thickness, tooth direction, and gear ring runout, scientifically determining the grinding allowance and grinding amount, eliminating unrepairable parts, and ensuring the success rate and effectiveness of repair.

[0012] Furthermore, the brushing mark mentioned in step (1) specifically involves brushing marks onto the surface of the involute spline to be ground, and then uniformly spraying paint.

[0013] The beneficial effect of adopting the above-mentioned further solutions is that it innovatively uses spray paint and markers as visual aids.

[0014] Furthermore, the thickness of the mark is 0.001mm to 0.002mm, and the thickness of the paint is 0.08mm to 0.12mm.

[0015] Furthermore, the installation method described in step (1) is a two-pin clamping.

[0016] Furthermore, the retraction amount during the retraction in step (2) is 0.10mm~0.15mm.

[0017] The beneficial effect of adopting the above-mentioned further solution is that it ensures that the forming grinding wheel does not come into contact with the spline when the machine tool is started for grinding.

[0018] Furthermore, in step (2), the cutting tool specifically refers to the marking cutting tool brushed onto the surface of the forming grinding wheel and the involute spline to be ground.

[0019] The beneficial effects of adopting the above-mentioned further solution are: the present invention innovatively uses spray paint and markers as visual aids, combined with the linkage of the Z-axis and A-axis of the spline grinding machine, and through the algorithm of "return deflection amount 1 / 2", it realizes the rapid and accurate centering and positioning of the forming grinding wheel in the tiny tooth grooves of the spline.

[0020] Furthermore, in step (2), the A-axis is specifically called back by 1 / 2 of the total A-axis deflection.

[0021] The beneficial effect of adopting the above-mentioned further solution is that it positions the forming grinding wheel symmetrically with the center of the tooth groove of the spline tooth.

[0022] Furthermore, the dynamic balancing in step (3) specifically involves: performing dynamic balancing according to the drawing requirements of the central transmission spline shaft, with the imbalance not exceeding 0.5 g·mm.

[0023] The beneficial effects of adopting the above-mentioned further solutions are: the repaired spline pair has good contact, the transmission is smooth, the accelerated wear of the spline is eliminated from the root, and the additional transmission reliability of the engine is improved.

[0024] Furthermore, the non-destructive testing in step (3) specifically involves using a magnetic particle flaw detector to perform surface defect detection to ensure that the spline surface is free of defects.

[0025] The beneficial effects of adopting the above-mentioned further solution are: the present invention breaks through the limitations of manual grinding, realizes micro-feed control through program control, and performs precise "point-to-point" removal of adhesive protrusions, ensuring that the grinding amount is controllable and avoiding damage to the spline substrate. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the repair process of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of spline grinding of the central drive spline shaft in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the central drive spline tooth surface grinding and tool setting in Embodiment 1 of the present invention. Detailed Implementation

[0027] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0028] Example 1: Grinding Repair Method for Central Drive Spline Shaft The grinding repair method in this embodiment is as follows: Figure 1 As shown, the specific steps are as follows: (1) Measure the actual pitch arc tooth thickness S of the involute spline to be ground in the central drive spline shaft: 1.199 mm, the actual gear ring runout Fr: 0.025 mm, and the current maximum tooth direction F. β实max 0.023 mm, spline crossbar dimension L: 13.860 mm; S min : 1.168mm; F β规max : 0.014mm.

[0029] Calculate the actual maximum grinding thickness L on one side of the involute spline to be ground in the central drive spline shaft. max The grinding amount ΔL is calculated using the following formulas: Formula ① and Formula ②. L max =S-(S min +Fr / 2) ① L max =0.0185 mm △L=F β实max -F β规max ② △L=0.009 mm; Where S min The theoretical minimum pitch arc tooth thickness; F β规max To specify the maximum value of the tooth direction; when L max If the value is ≥△L, the repair conditions are met and the item can be repaired; otherwise, it is scrapped.

[0030] (2) Use a standard mandrel to check and adjust the axis of the ejector pins on the left and right sides of the spline grinder to ensure that the axis is coaxial. At the same time, check that there are no abnormalities in the ejector pin hole of the involute spline shaft to be ground. Otherwise, use a scraper to locally scrape off the high point of the ejector pin hole until the coaxiality of the axis is less than 0.03 mm. Make process parts or use a scrapped central drive spline shaft to debug the spline grinder. Determine the grinding wheel tooth profile by inspecting the process parts so that the actual tooth profile of the spline shaft ground by the spline grinder is consistent with the parameters required by the spline drawing. The tooth profile Fα is not greater than 0.007 mm.

[0031] (3) Use a black marker to brush a 0.002mm mark on the surface of the involute spline to be ground on the central drive spline shaft, and then evenly spray red paint with a thickness of about 0.08mm~0.12mm. Using a two-pin clamping method, install the central drive spline shaft to be repaired on the spline grinding machine. Adjust the forming grinding wheel into the spline tooth groove of the central drive spline shaft until the grinding wheel contacts the spline. Feel the tightness from top to bottom and left to right; the resistance should be about (1-2) N·m. After initially determining the Z-axis and A-axis positions of the spline grinding machine, retract the tool from the Z-axis direction, controlling the retraction amount to 0.10mm~0.15mm, ensuring that the grinding wheel does not contact the spline when starting the spline grinding machine. Then... Figure 2As shown, the Z-axis is fed sequentially until the forming grinding wheel contacts one side of the involute spline tooth to be ground. The contact process is indicated by the appearance of a black marker on the spline surface. After one side of the spline tooth contacts the tool, the Z-axis dimension is recorded to control the next feed. The Z-axis dimension is related to the grinding wheel diameter and the workpiece diameter. When subsequent feeds approach this dimension, the feed speed should be reduced, and the contact between the grinding wheel and the workpiece observed to avoid collisions. The A-axis is then deflected to ensure the other side of the spline tooth also contacts the tool, and the A-axis deflection is recorded. The deflection is then controlled by adjusting the total deflection by 1 / 2, placing the forming grinding wheel symmetrically with the center of the spline tooth groove. Figure 3 As shown.

[0032] (4) Fine-tune the Z-axis again, feed a small amount of about 5 μm per cut, so that the forming grinding wheel and spline contact again. After contact, perform a small amount of grinding on the worn side of the spline teeth by deflecting the A-axis. The grinding amount is controlled between 0.009mm and 0.0185mm according to Lmax and ΔL. During the grinding process, ensure that the grinding amount is not greater than the calculated grinding allowance to avoid excessive grinding that leads to dimensional deviation.

[0033] (5) After grinding and repair, the involute spline inspection program of the gear measuring center is used to recheck the spline parameters such as tooth profile and tooth direction after grinding and repair. The tooth direction should not be greater than 0.014 mm, the tooth ring runout should not be greater than 0.03 mm, the tooth thickness should be 1.2470-0.079 mm, and the span bar dimension should not be less than 13.806 mm. Then, the grinding spline part is inspected by magnetic particle testing. No cracks are found. Finally, dynamic balancing is performed according to the requirements of the central drive spline shaft drawing.

[0034] Example 2: Grinding Repair Method Two for Central Drive Spline Shaft The grinding repair method in this embodiment is as follows: Figure 1 As shown, the specific steps are as follows: (1) Measure the actual pitch arc tooth thickness S of the involute spline to be ground in the central drive spline shaft: 1.202 mm, the actual gear ring runout Fr: 0.022 mm, and the current maximum tooth direction F. β实max 0.021 mm, spline crossbar dimension L: 13.864 mm; S min : 1.168mm; F β规max : 0.014mm.

[0035] Calculate the actual maximum grinding thickness L on one side of the involute spline to be ground in the central drive spline shaft. max The grinding amount ΔL is calculated using the following formulas: Formula ① and Formula ②. L max =S-(S min +Fr / 2) ① Lmax =0.023 mm △L=F β实max -F β规max ② △L = 0.007 mm; Where S min The theoretical minimum pitch arc tooth thickness; F β规max To specify the maximum value of the tooth direction; when L max If the value is ≥△L, the repair conditions are met, and repair can be carried out.

[0036] (2) Use a standard mandrel to check and adjust the axis of the ejector pins on the left and right sides of the spline grinder to ensure that the axis is coaxial. At the same time, check that there are no abnormalities in the ejector pin holes of the involute spline shaft to be ground. Otherwise, use a scraper to locally scrape off the high points of the ejector pin holes until the coaxiality of the axis is less than 0.03 mm. Make process parts or use a scrapped central drive spline shaft to debug the spline grinder. Determine the grinding wheel tooth profile by inspecting the process parts so that the actual tooth profile of the spline shaft ground by the spline grinder is consistent with the parameters required by the spline drawing. The tooth profile Fα is not greater than 0.007 mm.

[0037] (3) Use a black marker to brush a 0.002mm mark on the surface of the involute spline to be ground on the central drive spline shaft, and then evenly spray red paint with a thickness of about 0.08mm~0.12mm. Using a two-pin clamping method, install the central drive spline shaft to be repaired on both sides of the spline grinding machine, adjust the forming grinding wheel into the spline tooth groove of the central drive spline shaft until the grinding wheel contacts the spline, feel the tightness up, down, left and right, and the resistance is about (1-2) N·m. After initially determining the Z-axis and A-axis positions of the spline grinding machine, retract the tool from the Z-axis direction, controlling the retraction amount to 0.10mm~0.15mm, to ensure that the grinding wheel does not contact the spline when the spline grinding machine is started. Then as follows Figure 2 As shown, the Z-axis is fed sequentially until the forming grinding wheel contacts one side of the involute spline tooth to be ground. The contact process is indicated by the appearance of a black marker on the spline surface. After one side of the spline tooth contacts the tool, the Z-axis dimension is recorded to control the next feed. The Z-axis dimension is related to the grinding wheel diameter and the workpiece diameter. When subsequent feeds approach this dimension, the feed speed should be reduced, and the contact between the grinding wheel and the workpiece observed to avoid collisions. The A-axis is then deflected to ensure the other side of the spline tooth also contacts the tool, and the A-axis deflection is recorded. The deflection is then controlled to ensure the grinding wheel is centered. At this point, half of the total deflection is reversed to position the forming grinding wheel symmetrically with the center of the spline tooth groove. Figure 3 As shown.

[0038] (4) Fine-tune the Z-axis again, feed a small amount of about 5 μm per cut, so that the forming grinding wheel contacts the spline again. After contact, perform a small amount of grinding on the worn side of the spline teeth by deflecting the A-axis. The grinding amount is based on L. maxThe ΔL is controlled between 0.007mm and 0.023mm. During the grinding process, the grinding amount is ensured not to exceed the calculated grinding allowance to avoid excessive grinding that could lead to dimensional deviations.

[0039] (5) After grinding and repair, the involute spline inspection program of the gear measuring center is used to recheck the spline parameters such as tooth profile and tooth direction after grinding and repair. The tooth direction should not be greater than 0.014 mm, the tooth ring runout should not be greater than 0.03 mm, the tooth thickness should be 1.2470-0.079 mm, and the span bar dimension should not be less than 13.806 mm. Then, the grinding spline part is inspected by magnetic particle testing. No cracks are found. Finally, dynamic balancing is performed according to the requirements of the central drive spline shaft drawing.

[0040] Comparative Example 1: Grinding Repair Method for Central Drive Spline Shaft (1) Measure the actual pitch arc tooth thickness S of the involute spline to be ground in the central drive spline shaft: 1.198 mm, the actual gear ring runout Fr: 0.018 mm, and the current maximum tooth direction F. β实max 0.022 mm, spline crossbar dimension L: 13.858 mm; S min : 1.168mm; F β规max : 0.014mm.

[0041] Calculate the actual maximum grinding thickness L on one side of the involute spline to be ground in the central drive spline shaft. max The grinding amount ΔL is calculated using the following formulas: Formula ① and Formula ②. L max =S-(S min +Fr / 2) ① L max =0.021 mm △L=F β实max -F β规max ② △L=0.008 mm; Where S min The theoretical minimum pitch arc tooth thickness; F β规max To specify the maximum value of the tooth direction When L max If the value is ≥△L, the repair conditions are met, and repair can be carried out.

[0042] (2) Use a standard mandrel to check and adjust the axis of the ejector pins on the left and right sides of the spline grinder to ensure that the axis is coaxial. At the same time, check that there are no abnormalities in the ejector pin hole of the involute spline shaft to be ground. Otherwise, use a scraper to locally scrape off the high point of the ejector pin hole until the coaxiality of the axis is less than 0.03 mm. Make process parts or use a scrapped central drive spline shaft to debug the spline grinder. Determine the grinding wheel tooth profile by inspecting the process parts so that the actual tooth profile of the spline shaft ground by the spline grinder is consistent with the parameters required by the spline drawing. The tooth profile Fα is not greater than 0.007 mm.

[0043] (3) Use a black marker to apply a 0.002mm thick mark to the surface of the involute spline to be ground on the central drive spline shaft. Using a two-pin clamping method, install the central drive spline shaft to be repaired on both sides of the spline grinder. Adjust the forming grinding wheel into the spline groove of the central drive spline shaft until the grinding wheel contacts the spline. Feel the tightness from top to bottom and left to right; the resistance should be approximately (1-2) N·m. After initially determining the Z-axis and A-axis positions of the spline grinder, retract the tool from the Z-axis direction, controlling the retraction amount to 0.10mm~0.15mm, ensuring that the grinding wheel does not contact the spline when starting the spline grinder. Then, as... Figure 2 As shown, the Z-axis is fed sequentially until the forming grinding wheel contacts one side of the involute spline tooth to be ground. The contact process is indicated by the appearance of a black marker on the spline surface. After one side of the spline tooth contacts the wheel, the Z-axis dimension is recorded to control the next feed. The Z-axis dimension is related to the grinding wheel diameter and the workpiece diameter. When subsequent feeds approach this dimension, the feed speed should be reduced, and the contact between the grinding wheel and the workpiece observed to avoid collisions. The A-axis is then deflected to ensure the other side of the spline tooth contacts the wheel, and the A-axis deflection is recorded. The deflection is then controlled by adjusting the total deflection by half to position the forming grinding wheel symmetrically with the center of the spline tooth groove. Figure 3 As shown.

[0044] (4) Fine-tune the Z-axis again, and feed a small amount (about 5 μm per cut) to make the forming grinding wheel contact the spline again. After contact, perform a small amount of grinding on the worn side of the spline teeth by deflecting the A-axis. The grinding amount is based on L. max The ΔL is controlled between 0.008mm and 0.021mm. During the grinding process, the grinding amount is ensured not to exceed the calculated grinding allowance to avoid excessive grinding that could lead to dimensional deviations.

[0045] (5) After grinding repair, the involute spline inspection program of the gear measuring center was used to recheck the spline tooth profile, tooth direction, and other related spline parameters after grinding repair. The spline tooth direction should not exceed 0.014 mm, the tooth ring runout should not exceed 0.03 mm, the tooth thickness should be 1.2470-0.079 mm, and the span bar dimension should not be less than 13.806 mm as specified in the drawing. The actual measured span bar distance after repair was 13.794 mm, and the span bar dimension exceeded the drawing requirements.

[0046] Comparative Example 2: Grinding Repair Method for Central Drive Spline Shaft (1) Measure the actual pitch arc tooth thickness S of the involute spline to be ground in the central transmission spline shaft: 1.203 mm, the actual gear ring runout Fr: 0.028 mm, and the current maximum tooth direction F. β实max : 0.037 mm, spline crossbar dimension L: 13.866 mm; S min : 1.168mm; F β规max 0.014mm. Calculate the actual maximum grinding thickness L on one side of the involute spline to be ground in the central drive spline shaft. max The grinding amount ΔL is calculated using the following formulas: Formula ① and Formula ②. L max =SS min ① L max =0.035 mm; △L=F β实max -F β规max ② △L=0.023 mm; Where S min The theoretical minimum pitch arc tooth thickness; F β规max To specify the maximum value of the tooth direction When L max If the value is ≥△L, the repair conditions are met, and repair can be carried out.

[0047] (2) Use a standard mandrel to check and adjust the axis of the ejector pins on the left and right sides of the spline grinder to ensure that the axis is coaxial. At the same time, check that there are no abnormalities in the ejector pin hole of the involute spline shaft to be ground. Otherwise, use a scraper to locally scrape off the high point of the ejector pin hole until the coaxiality of the axis is less than 0.03 mm. Make process parts or use a scrapped central drive spline shaft to debug the spline grinder. Determine the grinding wheel tooth profile by inspecting the process parts so that the actual tooth profile of the spline shaft ground by the spline grinder is consistent with the parameters required by the spline drawing. The tooth profile Fα is not greater than 0.007 mm.

[0048] (3) Use a black marker to mark the surface of the involute spline to be ground on the central drive spline shaft, then evenly spray red paint with a thickness of about 0.08mm~0.12mm. Using a two-pin clamping method, install the central drive spline shaft to be repaired on both sides of the spline grinder. Adjust the forming grinding wheel into the spline groove of the central drive spline shaft until the grinding wheel contacts the spline. Feel the tightness from top to bottom and left to right; the resistance should be about (1-2) N·m. After initially determining the Z-axis and A-axis positions of the spline grinder, retract the tool from the Z-axis direction, controlling the retraction amount to 0.10mm~0.15mm, ensuring that the grinding wheel does not contact the spline when starting the spline grinder. Then, as... Figure 2As shown, the Z-axis is fed sequentially until the forming grinding wheel contacts one side of the involute spline tooth to be ground. The contact process is indicated by the appearance of a black marker on the spline surface. After one side of the spline tooth contacts the tool, the Z-axis dimension is recorded to control the next feed. The Z-axis dimension is related to the grinding wheel diameter and the workpiece diameter. When subsequent feeds approach this dimension, the feed speed should be reduced, and the contact between the grinding wheel and the workpiece observed to avoid collisions. The A-axis is then deflected to ensure the other side of the spline tooth also contacts the tool, and the A-axis deflection is recorded. The deflection is then controlled by adjusting the total deflection by 1 / 2, placing the forming grinding wheel symmetrically with the center of the spline tooth groove. Figure 3 As shown.

[0049] (4) Fine-tune the Z-axis again, feed a small amount of about 5 μm per cut, so that the forming grinding wheel contacts the spline again. After contact, perform a small amount of grinding on the worn side of the spline teeth by deflecting the A-axis. The grinding amount is based on L. max The ΔL is controlled between 0.023mm and 0.035mm. During the grinding process, the grinding amount is ensured not to exceed the calculated grinding allowance to avoid excessive grinding that could lead to dimensional deviations.

[0050] (5) After grinding repair, the involute spline inspection program of the gear measuring center was used to recheck the spline tooth profile, tooth direction, and other related spline parameters after grinding repair. The spline tooth direction should not exceed 0.014 mm, the tooth ring runout should not exceed 0.03 mm, the tooth thickness should be 1.2470-0.079 mm, and the span bar dimension should not be less than 13.806 mm as specified in the drawing. The actual measured span bar distance after repair was 13.788 mm, and the span bar dimension exceeded the drawing requirements.

[0051] Experimental example: The tooth direction and tooth thickness in Examples 1-2 and Comparative Examples 1-2 were tested using the ECON30 gear measuring center from Harbin Measuring & Cutting Tool Co., Ltd. The test data are shown in Table 1.

[0052] Table 1. Detection data before and after repair From Table 1, we can obtain: (1) This invention solves the problem of tooth direction deviation caused by adhesive wear of involute splines. The repaired involute spline pair has good contact and smooth transmission, fundamentally preventing the accelerated wear of involute splines and improving the transmission reliability of the engine. It restores the performance of spline shafts that were originally scrapped due to tooth direction deviation but still had remaining service life, saving the cost of purchasing new products and achieving cost reduction and efficiency improvement.

[0053] (2) During the implementation of Comparative Example 1, it was found that because no paint was sprayed as a buffer during the tool setting process in step (3), although the grinding amount in the subsequent grinding process was controlled between 0.008mm and 0.021mm, the actual grinding amount was greater than the feed amount, which caused the tooth surface to be over-grinded during the tool setting process, resulting in the product being scrapped.

[0054] (3) During the implementation of Comparative Example 2, it was found that when the tooth grinding was qualified, the tooth thickness was exceeded when the tooth thickness was tested. This was because the tooth ring runout was not considered in the calculation process, which led to an incorrect judgment on whether the product could be repaired. The scrapped product was repaired, resulting in a waste of resources.

[0055] In summary, this invention transforms the traditional "craft" that relies on worker experience into a standardized and replicable process, solving the problem of repair consistency and providing a valuable technical model for the repair of similar precision parts.

[0056] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0057] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0058] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0059] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A grinding repair method for a central drive spline shaft, characterized in that, The specific steps are as follows: (1) Adjust the spline grinding machine and brush a mark on the surface of the involute spline to be ground on the central drive spline shaft; install the central drive spline shaft on both sides of the spline grinding machine, adjust the forming grinding wheel into the tooth groove of the involute spline to be ground, until the grinding wheel contacts the spline, and feel the tightness up, down, left and right so that the resistance between the grinding wheel and the spline is 1N·m-2N·m; (2) Determine the positions of the Z-axis and A-axis of the spline grinding machine, retract the tool from the direction of the Z-axis, feed from the Z-axis to the side of the forming grinding wheel and the spline tooth of the involute spline to be ground, deflect the A-axis so that the other side of the spline tooth also contacts the tool, and retract the A-axis. (3) Fine-tune the Z-axis micro-feed again, feed 4μm~6μm per cut, so that the involute spline to be ground touches the tool again, deflect the A-axis to perform micro-grinding on the worn side of the involute spline to be ground, feed 0.01°~0.03° per cut, then perform non-destructive testing, and finally perform dynamic balancing according to the drawing requirements of the central drive spline shaft.

2. The grinding and repair method for a central drive spline shaft according to claim 1, characterized in that, The maximum grinding allowance L on one side of the involute spline to be ground in step (2) max Greater than or equal to the grinding amount ΔL; The maximum grinding allowance L max The calculation method is as follows: L max =S-(S min +Fr / 2); The grinding amount △L is calculated as follows: △L=F β实max -F β规max； Where S is the actual pitch arc tooth thickness of the involute spline to be ground; S min The minimum pitch radius tooth thickness is required by the drawing of the involute spline to be ground; Fr is the actual tooth ring runout of the involute spline to be ground; the F... β实max F represents the maximum tooth direction value of the involute spline to be ground; β规max The specified maximum value of the tooth direction of the involute spline to be ground.

3. The grinding and repair method for a central drive spline shaft according to claim 1, characterized in that, The brushing marking mentioned in step (1) specifically involves brushing markings onto the surface of the involute spline to be ground, followed by uniformly spraying paint.

4. The grinding and repair method for a central transmission spline shaft according to claim 3, characterized in that, The thickness of the marking is 0.001mm to 0.002mm, and the thickness of the paint is 0.08mm to 0.12mm.

5. The grinding and repair method for a central drive spline shaft according to claim 1, characterized in that, The installation method described in step (1) is a two-pin clamping.

6. The grinding and repair method for a central drive spline shaft according to claim 1, characterized in that, The retraction amount during retraction in step (2) is 0.10mm~0.15mm.

7. The grinding and repair method for a central drive spline shaft according to claim 1, characterized in that, In step (2), the contact tool is specifically the marking contact tool brushed on the forming grinding wheel and the surface of the involute spline to be ground.

8. The grinding and repair method for a central drive spline shaft according to claim 1, characterized in that, In step (2), the A-axis is specifically reverted by 1 / 2 of the total A-axis deflection, so that the forming grinding wheel is in a position symmetrical to the center of the tooth groove of the spline tooth.

9. A grinding repair method for a central drive spline shaft according to any one of claims 1 to 8, characterized in that, The dynamic balancing in step (3) specifically involves performing dynamic balancing according to the drawing requirements of the central transmission spline shaft, with the imbalance not exceeding 0.5 g·mm.

10. A grinding repair method for a central drive spline shaft according to any one of claims 1 to 8, characterized in that, The non-destructive testing in step (3) specifically involves using a magnetic particle flaw detector to perform surface defect detection to ensure that the spline surface is free of defects.

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