The drive ratio. When the level of the transmission gear ratio of 1 / 6-1 / 87. When the two-stage reduction gear ratio of 1 / 99-1 / 7569; when three transmission gear ratio is 1 / 5841-1 / 658503. Also, according to a multi-level needs can also be combined ratio reaches a specified large. 2. Transmission efficiency. Due to the use of a rolling engagement engagement portion, usually a transmission efficiency of 90% -95%. 3. Compact, small size and light weight. Volume and ordinary cylindrical gear reducer can be reduced compared to the 2 / 1-2 / 3. 4. Fault, long life. The main GEARING bearing steel grinding parts manufacturing, and therefore the mechanical properties and wear resistance are good, but also because of the rolling friction, thus less failure, long life. 5. smooth and reliable operation. Due process for multi-tooth gear meshing, so to make it smooth and reliable operation, low noise. 6. Easy disassembly, easy maintenance. 7. strong overload capacity, impact resistance, low moment of inertia for frequent starting and reversing operation characteristics.