Transmission roller bearing inner ring out reason and solution

Auto transmission, most of the traditional system of the rotating shaft by rolling bearing support, and to guarantee the stability of the rotation of the rotating shaft, here is the cylindrical roller bearing support the rotating shaft drive, in use process, found that the phenomenon of cylindrical roller bearing inner ring came out. The cause of cylindrical roller bearing inner ring out? If the solution is the best solution? In the following 崋 bearing network (for short ） According to the understanding of the bearings of knowledge, to share the related content. A, cylindrical roller bearing inner ring out fault phenomenon and affect the failure parts from the whole down inspection contents, as shown in figure 1, found that active axle of cylindrical roller bearing inner ring out inside the plane position 3 mm. If the cylindrical roller bearing inner ring out a certain distance, roller and bearing inner ring raceway surface not full length contact, can appear under the load bearing abnormal vibration, the vibration will directly affect the gearbox running the whole case, adverse noise, thus affect the normal use. Figure 1 cylindrical roller bearing inner ring out here is two, cylindrical roller bearing inner ring out the cause of the problem analysis, system structure analysis: 1 as shown in figure 2, according to the structure design, the ends of the active axle bearing, fixed end use deep groove ball bearings, free end USES the cylindrical roller bearing. Deep groove ball bearing caused by the radial steel belt and spindle hydraulic axial force. Cylindrical roller bearing is only from the wheel and axle passed steel belt tension, no axial force applied to the bearing, the cylindrical roller bearing was not influenced by the axial force to make it out. Figure 2 pulley system bearing force diagram 2, cause analysis: from the mechanical principle, two interference fit parts appeared out of the use process, either parts manufacturing error, reduce the fastening force is insufficient, or is the design with the interference of small make fastening force is insufficient, part work of thrust is greater than the binding force, so that the parts to move off. Bearing the emergence reason based on the idea of exploring. 1) Ruler is unqualified, size detection: if parts has lead to risk of bearing inner ring out. Bearing assemblies of two prototype measurement, the results are shown in table 1, comply with the design requirements, component size can be ruled out the impact factors. 2) Binding force calculation: bearing inner ring and the shaft is interference fit, the cause of the inner ring out may be enough for the design of interference. Check the size of the shaft and bearing design, found between the two under the limit state of the minimum interference quantity to zero. 002 mm, the combination of bearing inner ring and shaft can be through the following formula ( 1) Calculation: among them: P - The adhesion strength of the inner ring and shaft, Nd1 - The diameter of the shaft, mmd2 - Bearing inside diameter, mmB - Bearing contact with the inner ring width, mmE - Axial elastic modulus, Mpa according to the calculation, the bearing and axle interference quantity to zero. 002 mm, the combination of fastening force P is 23. 73 n, the value is too small, easy to make active axle of bearing inner ring caused by the insufficient tighten fixed bearing out. But in front of the structure analysis, the cylindrical roller bearing is not subject to axial force, also seems not mean binding force small will emerge problems, issues that need to be further explored. 3) Shaft and bearing load CAE analysis according to the figure 2 structure model, using computer software CAE analysis. According to the results of CAE analysis, axles are steel belt pull state as shown in figure 3; Shaft by steel belt tension state as shown in figure 4, under the action of wheel and axle force will produce certain bending deformation, and axial force on the bearing. Figure 3 axle in not subjected to the strip tension state when a tutu 4 wheel under the strip tension deformation diagram at the same time, the active axle CAE analysis results show that the contact on the cone flange steel strip, deformation, as shown in figure 5, the largest steel belt tensile deformation of bearing position of 0. 084毫米。 Cone flange deformation and axial force on the bearing. Figure 5 wheel shaft bending CAE analysis of cloud picture 3) Reason to confirm according to the above analysis shows that under the influence of the strip tension, not simply does not exist between shaft and roller bearing axial force, plus product manufacturing and assembly error, the axial force increases. When the shaft stress and manufacturing operation error caused by the axial force sum greater than bearing, the combination of fastening force bearing will happen in the original location on the axle sliding. Shaft deformation of axial force of numerical calculation is complicated, here is not for concrete calculation is derived. From the CAE analysis results - — Active shaft cone flange bearing level 0. 084 mm deformation is not too small, axial force bearing and shaft of the minimum interference quantity in combination with 23 fastening force. 73 n compared with must slim. Thus, can confirm that this CVT product active axle in bench test of cylindrical roller bearing inner ring out the cause of the problem, component design is given enough bearing and shaft with interference, has no bearing on the shaft and the structural design of the limit of the structure. Three solutions for the above confirmed that the two aspects of reasons, develop the two measures to solve the problem: a) Increase of the bearing inner ring and the shaft. Adjust the shaft diameter tolerance of bearing fit place, will minimize the wheel and the cylindrical roller bearing with interference quantity by 0. 002 mm up to 0. 011mm。 b) The bearing inner ring increase a limit resistance structure. On the wheel and axle bearing with lateral position to add a ring groove, mount retaining ring, to limit the bearing inner ring, prevents the inner ring out, as shown in figure 6. Figure 6 ring installation sketch map