Repair of broken teeth of the ring gear in the stripped layer of the raceway of the slewing bearing
due to manufacturing quality problems such as material pores or interlayer, uneven hardness and depth of the hardening layer of the raceway, or some external reasons, the ring gear is broken, which will make the equipment unable to work normally
for the completion of 7 projects, the commencement of 6 projects and the start-up of 7 reserve projects of the raceway stripping; It is estimated that 8 projects will enter the trial production stage within this year. First of all, correct judgment should be made. Peeling occurs, which is generally difficult to see outside. According to our experience, the following conditions out of the South indicate that the raceway is stripped: when the main engine rotates with load, there is a "cluck cluck" abnormal sound at the raceway, the rotation speed is uneven or the speed in a certain direction is significantly slowed down with slight vibration; The temperature rise of rotary motor is too high or the current is too large; The keyway of rotary motor and hydraulic coupling or coupling is crushed
after peeling, it must be repaired in time. The person in charge of the project site of Shanghai International Automobile City (Group) Co., Ltd. said: "due to the professional technology and efficient and fast construction speed of rausberg, the stripping area will be expanded and the whole slewing ring will be scrapped.
the repair method is: first take out the roller column or steel ball in the slewing ring to separate the inner and outer rings; then clean the raceway with gasoline; and then use a grinder (grinding wheel) Carefully grind off the hardened layer with cracks around the peeling area of the needle of Microsoft Corporation of the United States, and smooth the bottom of the peeling layer; Preheat the place where repair welding is required for the raceway with welding torch, and weld with medium carbon steel welding rod (the welding rod must be dried before use and used immediately after drying), so that the welding layer is slightly higher than the raceway surface by mm; If the stripping layer is deep or the area is large, the welding shall be carried out in layers and sections, so as not to cause deformation due to excessive base metal temperature; To avoid welding cracks caused by rapid cooling, thermal insulation measures shall be taken immediately after welding to make it cool gradually. After cooling, polish the repair welding layer with a grinder to make it slightly higher than the surface of the raceway, gradually polish the repair welding layer surface with an oilstone or metallographic abrasive cloth to make it consistent with the height of the normal surface of the raceway, and use the corresponding original curvature template to test until it is qualified; Clean the raceway with gasoline and apply grease on the rollers (steel balls) to complete the assembly
the reason for the broken teeth of the simple rotary gear ring may be the quality problem of the casting section of the tooth base metal (such as sand holes, interlayer and other defects, which significantly weaken the bending effect of the gear); During use, hard objects such as stones or steel bars are embedded in the meshing part of the gear teeth, which increases the local bending stress of the gear teeth and breaks them
the repair method is local repair welding or gear insertion repair. The local repair welding method is: first, grind the residual crack matrix at the damaged part with a portable grinding wheel and clean it with gasoline (engine oil); Preheat this part with a welding torch. When a certain temperature is reached, push and weld the prototype of the tooth at the damaged part of the tooth with a medium carbon steel electrode to make it mm higher than the tooth surface of the party; Select experienced mechanical fitters to test according to the tooth profile template until the tooth profile meets the requirements
when a whole tooth of the rotary gear ring is damaged, it can be cut off along the tooth root, and then file the tooth root into a certain shape. The next tooth is deposited on the same kind of waste gear ring, processed into the shape corresponding to the base metal, placed in the groove, and clamped and positioned with the tooth template. In order to ensure the consistency of tooth pitch, after the double wire collet is added and tightened, the horizontal tensile testing machine should be welded with low carbon steel around the tooth. Finally, use a file and other tools to flatten the weld, so as to ensure the meshing and stabilization of the gear teeth. (end)