During the use of construction machinery equipment, various problems can not be avoided. Sometimes the turntable bearings suddenly break, which will not only affect the production progress, but also cause huge losses, and may also danger. What is the reason why Hengguan Xiaobian will analyze the reasons why the lower turntable bearing broken phenomenon will be analyzed today.
Reasons for the break of the rotor bearing
1. Material problem
The phenomenon of rotor bearing breaks can be said to be a major quality problem of this part. The rotor bearing breaks refer to the inner and outer ring of the inner and outer circles of such bearing, mainly because the tensile strength, yield strength, and impact toughness of the material are not up to the standard. Mechanical properties of making such bearing materials. The main material of the rotor bearing is carbon structure steel. 50mn and 42CRMO are commonly used in this industry. 50mn mechanical performance: (1) tensile strength σb (MPA): ≥645 (66); (2) Lading strength σs (MPA): ≥390 (40); (3) elongation rate Δ5 (%): ≥13: ≥13 ; (4) Sectional contraction 断 (%): ≥40; (5) impacting AKV (J): ≥31; (6) impact tough value αKV (j/cm2): ≥39 (4). When the turntable bearing work at a normal use temperature (-30 ° C to 70 ° C), it can basically be sure of the factors of the material problem.
2. Processing heat treatment
The production and processing process needs to be heat treatment of the rolling roads. The heat treatment fails, resulting in low surface hardness. The hardness layer penetrates into the wall of the rotary bearing structure or reaches the rotary supporting wall, which changes the mechanical performance of the internal and external circles. The value becomes smaller and the material becomes crispy.
3. Design structural problem
After the design structure of the turntable bearing is caused by heat treatment, the quenching layer is equivalent to the design thickness of the inner and outer circle. At this time, the material anti -tensile strength and the impact toughness value is small, resulting in a break, but this possibility accounted for a low proportion of the broken accident.
There are many reasons for the phenomenon of rotor bearing. When using an unspoken ring forged, the quality of the bearing material is unqualified. Bearing manufacturers, so that the material and design of the bearing can be guaranteed.