After long-term use of truck cranes, ring windmill deceleration may cause abnormal noise, heating, oil leaks and other conditions.The wear and tear of the bearing seat and the drop of the bearing outer ring indicate that the reduction shell is made of cast steel with poor welding, and pores and cracks are easily produced during the welding process.When the crane rotates, the bearing seat hole will have a certain vibration and impact force, and the material hardness needs to be medium, with a certain impact and vibration.
1. Partial replacement method
Measure and map reducer housings and process new bearing housings with high-strength material; use a lathe to cut bearing housings for rotary reducer housings, then interface and thread to newly made bearing housings; thread newly manufactured bearing housings The finished bearing seat is connected with the restored shell, the steel bar is filled on the restored shell by welding method, and then the interface parts are welded; the new bearing seat hole is completed to the design size.
2. Mosaic method
Clean the bearing seat hole, then drill the seat hole with a boring machine to enlarge the seat hole; the outer diameter of the cast steel insert of the turn is the interference with the boring seat hole.Fit the insert into the enlarged housing hole and finish it to design size.The method is simple and the maintenance time is very short.The downside is that the removal requirements are high.
3. Welding method
The reducer uses a boring machine to drill the seat hole, then increases the diameter of the seat hole appropriately; put the shell in the oven, preheat it to about 400°C, and heat the seat hole to a red hot state (about 900 ~950℃); paved with copper alloy electrodes to a predetermined thickness, then put it in an oven for cooling, and then complete the transverse seat hole to the design size.The advantage is that the repaired bearing seat hole has good impact and vibration, stable quality and long service life.The disadvantages are complicated welding repair process, long cycle, high cost and easy wear after repair.
According to the comprehensive analysis, the latter two methods have many advantages, but they are not suitable for repairing the shell bearing seat of the annular windmill reducer.
