Planet gear drive mechanism has lots of advantages, such us small in size, light in weight, large in ratio of drive, high in load ability , good in stability , and it is used in MEMS widely.

Micro planetary gear reducer is the important part in MEMS.

Based on the characteristic of NGW-S type planetary gear reducer, the objective function whose volume is the smallest is put up.

3D parameterized CAD system of planet gear reducer based on Pro/E;

The number of teeth,modulus and ply of sun gear and the number of planet gear are the parameter of the main scantling of structure in design of planet gear reducer.

Mathematical model of optimization design for planetary gear reducer;

Effect of planetary gear reducer on safety of the hoisting mechanism;

Optimization design of the planetary gear reducer based on Matlab;

Considering the meshing stiffness and damping of the gear pairs and stiffness of the bearings,the dynamics governing equations of an inner planetary gear reducer witi three axes were established based on the lumped mass method.

Considering the meshing stiffness and damping of the gear pairs and stiffness of the bearings,the dynamic governing equations of an inner planetary gear reducer with three axes are established based on the lumped mass method.