Study On Fracture Splitting Process Of Reducer Bearing Seat Of Medium And Heavy Duty Truck

The rapid development of the vehicle industry raises a higher requirement to the manufacture of car components. Study on the new production method of the the bearing seat, an important transmission component, is of certain practical significance. Reducer bearing seat, under both sides of the axial force during the driving, is mainly used to support the gear and transmission shaft.The bearing seat is easy to cover dislocation under the severe cyclic loading. The reducer bearing seat which is processed through the method of fracture splitting is able to bear the severe cyclic loading without dislocation. Compared with the traditional method, the technique has remarkable advantages, such as good meshing performance, high positioning precision, less working procedures, low cost, strong carrying capacity and reliable quality, so the article focuses on the new manufacture method. The method of fracture splitting process is as follow:firstly, the crack groove is preprocessed on the material, forming high stress concentration, then cracks are created under the applied load, ultimately the separation of the material is approached. Since the crack groove parameters is a factor of the fracture splitting process, which has a greater effect on the bearing seat’s fracture splitting than any other factors, we mainly focus on the numerical simulation of broaching, wire-electrode cutting, laser processing prefabricated crack groove.The main research contents and conclusions are as follows:1. Broaching prefabricated crack groove’s numerical simulation:firstly, the article designs a three-factor-and-four-level orthogonal test table of depth, angle and curvature radius to analyze its significant effect on the cracking load. Then it explores the effects of depth, curvature radius, angle on the J integral value, crack tip’s splitting time, S 33, cracking load. The most significant effect of the groove depth on the cracking load, influence of curvature radius on it significantly, but insignificantly affect the angle of it.Groove depth is deeper, the J integral value is greater, crack tip’s initiation time is shorter, the S 33 is greater and the cracking load is smaller; with the increase of the curvature radius, the J integral value and the S 33 fall quickly at first, then remain unchanged. The crack tip’s initiation time and cracking load gradually increased and then sustain the same level; overall, angle has little effect on the J integral value, crack tip’s splitting time, and cracking load. The depth has a greater effect than the curvature radius on them.2. The numerical simulation of wire-electrode cutting and laser processing prefabricated crack groove, exploring the influence of depth on J integral, crack tip’s splitting time, S 33, cracking load. Along with the increase of the groove depth, the J integral value of the two crack slots and the S 33 are gradually increased, and the crack initiation time and the cracking load decrease gradually. The effect of laser prefabricated crack groove depth on them is more significant.3. The starting position of the crack in reducer bearing seat is the tenth node of the crack tip, which has nothing to do with the processing methods of the crack groove. The deviation between the actual cracking load and simulated cracking load is 4.30% through the experiment of 1.0mm laser prefabricated crack groove, which verified the accuracy of the simulation results. The average change of specimens’ inner diameter is 0.27mm, which is within the acceptable range. Combined with the actual production conditions and the results of the analysis, the laser optimum crack groove parameters are as follows:depth ranges from 0.8mm to 1.0 mm and the corresponding cracking loads are:603.72 KN,586.92 KN, 575.12KN.