Common wear forms of large open gear

Failure mode of open gear

The main failure modes of open gear are pitting corrosion, spalling, plastic deformation, gluing, broken teeth and abrasion.

(1) Pitting. The main reason of pitting corrosion is the insufficient contact fatigue strength of gear surface interface.

(2) Spalling. Due to the fracture caused by high cyclic Hertz stress and the massive separation of surface metal, that is, the pitting area diffuses with the increase of gear running time.

(3) Plastic deformation. Due to friction extrusion deformation, fatigue and other factors, gear tooth surface material sliding phenomenon.

(4) When the surface temperature of the glued tooth surface is higher than the recrystallization temperature, the plastic deformation occurs, and obvious wave crest and groove are formed along the sliding direction.

(5) Other forms of injury. Abrasion, broken teeth, crush and rust.

Lubrication requirements and forms of large open gear

The lubrication requirements of large open gear are as follows: high viscosity, good adhesion to the gear surface during operation, not easy to drop; strong wear resistance and high extreme pressure resistance, FZG > 12, four ball sintering load > 650kg; high bearing capacity; spray lubrication requires good pumping performance, oil bath lubrication has good flow performance; lubricant It has good physical and chemical stability, good resistance to high temperature, dust and water. It has no impact on the operator’s body and no harm to the environment.

At present, the lubrication forms of large open gear include spray lubrication and oil bath lubrication, which have their own advantages and disadvantages. Using spray lubrication method, the lubrication effect of gear tooth surface is better, and the discharge of lubricant is also better controlled, which can make the site environment clean and tidy. However, spraying lubrication needs one-time equipment input, high oil cost and increased maintenance points. Spray lubrication is the mainstream choice for customers at present. With immersion lubrication, the gear tooth surface lubrication effect is obvious, the oil cost is low, and the labor intensity of maintenance personnel is small. However, if the gear surface is polluted by dust leakage, the tooth surface will be damaged quickly, and the waste of oil change will be very large.