CN-122013174-A - Gear broken tooth damage repairing method

CN122013174ACN 122013174 ACN122013174 ACN 122013174ACN-122013174-A

Abstract

The invention belongs to the technical field of laser cladding remanufacturing and relates to a gear broken tooth damage repairing method. The method comprises the steps of firstly adopting a machining method to remove all areas of a tooth to be repaired, continuously cutting the areas inwards, obtaining a groove with a flat bottom surface and no defects and parallel to a gear axis in a root circle, collecting gear parameters, preheating a gear matrix, taking the bottom surface as a base surface, determining technological parameters, selecting a scanning mode to carry out basic tooth profile cladding, continuously cladding after the groove is filled, obtaining a basic tooth profile similar to a trapezoid, reserving cladding allowance on a tooth side, adopting a laser head vertical and a tooth side inclined relative position posture, adopting gradient composite powder to carry out tooth side cladding material adding, obtaining a gradient cladding layer, supplementing the cladding allowance reserved for the basic tooth profile, removing the machining allowance of the tooth surface, carrying out finish machining and heat treatment on a repairing layer, improving the precision and the performance of the repaired tooth, and checking the performance of the repaired gear.

Inventors

LI TAO
WANG YUHENG
KONG XIANGLU
MO BIN
Peng Yunchuan
LIU WEIWEI
LIU SHUJIE

Assignees

大连理工大学

Dates

Publication Date: 20260512
Application Date: 20260225

Claims (3)

1. A broken tooth damage repairing method of a gear is characterized in that all areas of the broken tooth to be repaired of the gear are removed through a machining method, the inner side of a tooth root circle is continuously cut, and a groove with the bottom surface parallel to the axis of the gear is obtained; the method comprises the steps of preheating a gear matrix, taking the bottom surface as a base surface, combining original design parameters of a gear, carrying out basic tooth profile cladding in a multi-channel multi-layer mode by adopting optimal technological parameters to obtain a basic tooth profile similar to a trapezoid, reserving cladding allowance for subsequent laser cladding processing, carrying out tooth side cladding material adding by selecting proper technological parameters according to the relative position posture of vertical laser head and inclined tooth side, preparing a gradient cladding layer so as to simultaneously meet the requirements of internal and external performances of the gear, carrying out shaping and heat treatment on a repaired tooth, and finishing repairing broken teeth of the gear.
2. The method for repairing broken tooth damage of gears according to claim 1, comprising the specific steps of: step 1, preprocessing the gear Removing all areas of the gear to be repaired and broken teeth by using a machining method, continuously cutting the areas inwards to obtain a groove with the bottom surface parallel to the axis of the gear in a root circle, grinding the groove by using a grinding wheel, trimming the groove, cleaning by using acetone, and drying to ensure that no waste and solution remain; step 2, carrying out basic tooth profile cladding on the broken gear teeth According to the material of the repaired gear, selecting iron-based powder, preheating alloy powder and a gear matrix to be repaired so as to reduce the generation of cracks, adjusting technological parameters, taking the bottom surface of an obtained groove as a base surface, enabling a laser head to be perpendicular to the base surface, cladding the base tooth form by adopting a multi-layer cladding method, filling the removed part of the inner side of a tooth root circle and obtaining a nearly trapezoidal base tooth form, namely reserving cladding allowance; Step 3, carrying out tooth flank cladding material adding After preheating powder, adopting a mode of overlapping the laser head vertically and the inclined relative position posture of the tooth side surface from bottom to top by unidirectional scanning, avoiding interference between the laser head and the gear and reducing the influence of gravity, keeping a molten pool stable, carrying out laser cladding by using the optimal technological parameters, turning the gear to carry out cladding material adding on the tooth surface on the other side after the completion of laser cladding, and removing the tooth surface machining allowance after the completion of laser cladding; step 4, post-processing and performance testing The method comprises the steps of carrying out heat treatment on the clad gear, improving the strength and hardness properties of the repair layer and reducing residual stress, carrying out finish machining on the repair layer after the heat treatment process, further improving the tooth form precision by adopting machines such as a high-precision milling machine, a forming gear grinding machine and the like, and carrying out performance test on the repair area after finishing the finish machining to ensure that the repair area meets the use standard.
3. The method for repairing broken tooth damage of gear according to claim 2, wherein in step 2, the tooth thickness of the basic tooth form is smaller than the design value.

Description

Gear broken tooth damage repairing method Technical Field The invention belongs to the technical field of laser cladding remanufacturing and relates to a gear broken tooth damage repairing method. Background Gears are typical transmission elements and are widely used in various fields such as aerospace, automobile manufacturing and the like. The gear manufacturing mode is complex, the manufacturing cost is high, but the gear is often in service under severe conditions such as high temperature and high load, and is extremely easy to generate failures such as abrasion, pitting and the like due to improper manual operation, and serious broken teeth and huge economic losses are generated due to direct scrapping. The gear broken teeth are repaired, so that economic benefits can be obtained, and the environment is facilitated. The laser cladding technology is an advanced remanufacturing technology, and is a main stream means for repairing the current gear due to the advantages of small heat affected zone, good combination property and the like. Aiming at broken teeth restoration, the patent 'a gear laser cladding restoration method' (CN 114686878A) provides a laser cladding gear broken teeth restoration method, cladding layer by layer and milling to meet the height requirement of each layer so as to finish broken teeth restoration, and the gear laser cladding restoration method has the advantages that through calibrating the height of each layer of a cladding layer, residual stress is reduced, the problems of interlayer accumulated error and light spot dispersion in the later period of restoration are solved, and the gear laser cladding/height calibration and milling are needed to be alternately carried out layer by layer, so that the calculation and operation are complex, the processing efficiency is lower, and the involute surface precision is difficult to guarantee. The patent 'broken tooth repairing method based on laser cladding technology' (CN 120608278A) invents a broken tooth repairing method of a coal mine mechanical gear, which has the advantages of prolonging the service life of the gear and expanding the life cycle of the gear, but has the disadvantages of undefined repairing process path and scheme and different properties of a matrix and powder. In summary, the existing broken tooth repairing method still has the problems of low machining efficiency, difficult guarantee of tooth form precision and the like, and is difficult to meet different performance requirements of the inner side and the outer side of the gear at the same time, so that the broken tooth repairing method capable of realizing continuous transition of materials and performance is required to be invented, tooth form precision and gear performance after repairing are improved, and efficient utilization of resources is realized. Disclosure of Invention In order to solve the problems in the prior art and improve the tooth form precision after the broken tooth repair of the involute gear and the bonding strength between a gear matrix and a repair layer, the invention provides a broken tooth damage repair method of a gear. The method comprises the steps of firstly completely removing all areas of broken teeth of a gear by using a machining method, continuously cutting the areas inwards, constructing a groove which is parallel to the axis of the gear and smooth and flawless on the inner side of a root circle, collecting gear parameters, taking the bottom surface as a base surface, continuously carrying out laser cladding after the groove is filled, obtaining a basic tooth form similar to a trapezoid, and reserving certain cladding allowance on two sides of the edge of a cladding layer. And (3) carrying out gradient component design on the iron-based powder and the nickel-based powder, carrying out tooth side cladding and material adding to obtain a gradient cladding layer with gradually changed powder concentration, carrying out shape modification treatment on the tooth surface after cladding is finished, removing redundant cladding parts of the tooth surface, and carrying out heat treatment. The gradient cladding layer can realize continuous transition of components and performances and reduce the generation of cracks, so that the high-efficiency and high-performance repair of the broken tooth damage of the gear is realized. The repairing method can enable the tooth profile of the gear to be more in accordance with the involute shape, reduce the collapse of the cladding edge, reduce the tooth profile error, reduce the subsequent milling finish machining man-hour, improve the performance of the repaired gear, and can adapt to the repairing of different gears, thereby realizing the saving of resources and the efficient utilization of materials. The technical scheme adopted by the invention is as follows: A method for repairing broken tooth of gear includes such steps as machining all the areas of broken tooth of gear to be repaired, cutting