What are the main failure modes of closed soft-tooth-surface gear transmission?

[StRonan]

Here are the main failure modes of closed soft-tooth-surface gear transmission: 1. Tooth breakage: Tooth breakage usually occurs in two situations: (1) One is fatigue breakage caused by repeated bending stress and stress concentration; (2) The other is overload breakage caused by sudden severe overload or impact load. 2. Pitting corrosion: During gear operation, under the repeated action of alternating contact stress at the meshing point, several small cracks will appear on the tooth surface near the pitch line. As the cracks expand, small pieces of metal will peel off, a phenomenon known as pitting corrosion. Continued expansion of pitting corrosion will affect the smoothness of transmission, generate vibration and noise, and prevent the gear from working properly. 3. Tooth surface wear: During gear meshing, due to relative sliding, especially when external hard particles enter the meshing working surface, tooth surface wear will occur. As wear progresses, the tooth surface will lose its correct shape, and in severe cases, the tooth will become too thin and break. Tooth surface wear is the main failure mode of open gear transmission. To reduce wear, important gear transmissions should use closed transmission and pay attention to lubrication. 4. Tooth surface adhesion: In high-speed and heavy-duty gear transmissions, the pressure between tooth surfaces is high, the temperature rises, and lubrication is poor. When the instantaneous temperature is too high, the two tooth surfaces will partially melt and the metal will adhere to each other. When the two tooth surfaces move relative to each other, the adhered areas will tear, forming banded or large-area scars along the sliding direction. In low-speed and heavy-duty transmissions, oil film formation is difficult, and although frictional heat is not significant, cold adhesion may still occur due to heavy loads. 5. Tooth surface plastic deformation: For soft-tooth-surface gears with lower hardness, under low-speed and heavy-duty conditions, excessive tooth surface pressure and friction can cause the metal on the tooth surface to undergo plastic flow and lose its original shape. Increasing tooth surface hardness and using high-viscosity lubricating oil can help prevent or reduce tooth surface plastic deformation.