Worn Or Scratched Gear Teeth

Worn or scratched gear teeth
The causes of gear tooth surface wear or scratches are generally divided into adhesive wear, abrasive wear and scratches, corrosion wear and burns.
Adhesive wear - under the conditions of low speed, heavy load, high temperature, poor tooth surface roughness, insufficient oil supply or too low oil viscosity, the oil film is easily damaged and adhesive wear occurs. The high viscosity of lubricating oil is beneficial to prevent the occurrence of adhesive wear.
Abrasive Wear and Scratches - Lubricating oil contains foreign particles and foreign sand particles in open gear transmission or metal wear debris generated during friction, which can cause abrasive wear and scratches. Generally, the friction of the tooth top and the tooth root is more severe than that of the pitch circle, because the pitch circle is in rolling contact during the gear meshing process, while the tooth top and tooth root are in sliding contact.
Corrosion and wear - damage to the tooth surface due to the chemical reaction of some chemicals in the lubricating oil, such as acids, alkalis or water, with the tooth surface to cause corrosion of the metal.
Burns - Burns are local overheating caused by excessive friction caused by overload, overspeed or insufficient lubrication. This temperature rise is sufficient to cause discoloration and overaging, which will re-quench the several micron thick surface layer of the steel and cause whitening. Floor. Damaged surfaces are prone to fatigue cracks.
The occasions where gear tooth surface wear or scratches occur are generally open transmissions.
Preventive measures for gear tooth surface wear or scratches include the use of closed transmission, increasing the hardness of the tooth surface, reducing contact stress, reducing the surface roughness value, and keeping the lubricating oil clean.