The gearbox has a certain design service life, and it will fail due to wear after a certain period of operation under normal condition. In addition, manufacturing, assembly, operation, use and maintenance and other reasons will also cause failure of various components of the gearbox. In the main components of gearbox, such as gear, rolling bearing, shaft, box, fastener and seal, nearly 80% of faults occur in gear and rolling bearing (60% for gear and 60% for bearing) 19%), and these two parts usually have mutual influence when they have faults, bearing faults will affect the gear meshing state, and also show as gear faults, so it is necessary to focus on the gear and rolling bearing, and analyze their typical fault types and causes.
1. Type and cause of gear failure
According to statistics, the proportion of fault types of gears is: broken teeth account for 41%, abnormal tooth surface accounts for 31%, wear accounts for 10%, others account for 18%. See table 2-1 [1 accounts for 10%, others account for 18% for different fault types and causes.
2. Fault types and causes of rolling bearing
Generally, the outer ring of the rolling bearing is fixed and matched with the bearing seat or box body, the inner ring is tightly matched with the journal, and the inner and outer rings are separated from the rolling body by the lubricating oil film, which is used to support the shaft and the rotating parts on the shaft, and bear the radial and biaxial loads at the same time. Because of its high speed, heavy load, poor working environment, it is easy to fail, and the failure rate accounts for the total number of equipment failures 7%, most of the faults occurred in inner ring, outer ring and rolling body, the main types of faults are wear, fatigue peeling, gluing, fracture, corrosion, etc.