Gear commonly used steel tempered steel, hardened steel, carburizing and nitriding steels. Slightly lower strength than cast steel, forged steel, commonly used in large size gears; poor mechanical properties of grey cast iron, open gear drives that can be used for light loads; nodular cast iron parts to replace steel gear plastic gear used for light loads and requirements where low noise, paired with steel gears of gear with good thermal conductivity.

Gear in the future is to overload, high speed, high precision and high efficiency, direction, and small size, light weight, long life and reliability.

And gear theory and manufacturing process of development will is further research tooth injury of mechanism, this is established reliable of strength calculation method of according to, is improve gear hosted capacity, extended gear life of theory based; development to arc tooth profile for representative of new tooth shaped; research new of gear material and manufacturing gear of new process; research gear of elastic deformation, and manufacturing and installation errors and temperature field of distribution, for tooth repair shaped, to improved gear running of smooth sex, and in full Shi increases tooth of contact area, So as to improve the carrying capacity of gears.

Friction, lubrication and lubrication technology is the Foundation of gear research work, study on elastohydrodynamic lubrication theory, promote the use of synthetic lubricants and added to it as appropriate and extreme pressure additives in the oil can not only improve the bearing capacity of tooth surface, but also to improve the transmission efficiency.