Spur gear is a kind of gear transmission mode, which consists of a pair of meshing gear teeth, both ends of the plane parallel and the gear teeth are arranged in a straight line. Spur gears are usually used to transmit rotary motion and torque. They transmit power through the meshing between teeth to realize power transmission between different shafts. Widely used in various fields, especially in machinery manufacturing, aerospace, automotive industry, power industry and heavy machinery manufacturing and other fields.