A gear with teeth on the inner cylindrical surface. The teeth can be either spur or helical. Internal gear teeth have a concave rather convex shape with a thicker base than an equivalent external gear. This not only gives it greater tooth strength but due to a lower sliding velocity along the tooth profile, also makes them quieter.

Module- 6 Module etc

Applications: Various equipments used in industrial sectors such as Cement plants, Sugar mills, Fertilizer plants, Thermal power station, Mineral plants, Chemical plants, Paper mills, Mining Industry, Steel rolling plants, Textile plants, Material handing equipments, machine tools etc.