After long-term use of the truck crane, the cycloid pinwheel deceleration may cause abnormal noise, heating, oil leakage and other conditions. The wear and fracture of the bearing seat and the falling off of the outer ring of the bearing indicate that the reducer shell is made of cast steel with poor weldability, and it is easy to produce pores and cracks during welding. When the crane rotates, the bearing seat hole bears certain vibration and impact, and the material hardness is required to be moderate, with certain impact and vibration resistance.
1. Partial replacement method
Surveying and mapping the bearing seat of the reducer, and processing a new bearing seat with high-strength materials; Use the lathe to cut off the bearing seat from the rotary reducer housing, and turn the interface and thread connected with the newly made bearing seat; Connect the newly made bearing seat with the reducer housing through threads, fill the reinforcing ribs on the reducer housing with welding methods, and then weld the interface parts; Finish the new bearing seat hole to the design size.
2. Inlay method
Clean the bearing seat hole, and then bore the seat hole with a boring machine to enlarge the seat hole; The outer diameter of the turned cast steel insert is an interference fit with the bored seat hole; Install the insert into the enlarged seat hole and finish it to the design size. The method is simple and the repair time is short. The disadvantage is that the clearance requirements are high.
3. Welding method
The reducer uses a boring machine to bore the seat hole, and then appropriately increase the diameter of the seat hole; Put the shell into the oven and preheat it to about 400 ℃, and then heat the seat hole to a red hot state (about 900~950 ℃); Surfacing with copper alloy electrode to the predetermined thickness, and then put it into the oven for cooling, and finish the surfacing seat hole to the design size. The advantages are that the repaired bearing seat hole has good impact and vibration resistance, stable quality and long service life. The disadvantages are complex 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 the repair of the shell bearing seat of cycloid pinwheel reducer.
