The Systematic Design and Meshing-Efficiency Analysis of Gear Reducer for Gear-Motor

Recently, the power system equipped in elevator contains motor and gear reducer to get large output torque. In general, the motor and gear reducer of elevator are designed and manufacture separately. The matching and assembly are conducted only when these two main parts are accomplished as independent components. Its chief advantage is the reduced complexity of the related design process. Conventionally, the motor and gear reducer are two devices which are connected by a coupling. However, the power system would constitute a variety of problems such as larger amount of components, heavy weight, longer power-path, and large installation space. The purpose of this paper is to present new design concept which Integrates motor and gear reducer into one single device and named as "gear-motor". This allocation has four advantages: 1. less friction loss an, higher overall efficiency, 2. smaller volume, less weight, and less axial space, 3. better dynamic balancing characteristic, less vibration, and less noise, and 4. small cogging torque and torque ripple of motor. First, according to the combining and eliminating methods of check list, we proposed four design concepts "gear-motor". Based on the concept of train value equation of the train circuit, the 2-stage planetary gear reducer and coupled type gear reducer are synthesized. Then, according to the latent power theorem, the meshing efficiencies of 2-stage planetary gear reducer and coupled type gear reducer are analyzed to be 95.46% and 95.87%. Finally, the engineering design is accomplished to illustrate the design methodology. Based on the proposed methodology, all gear-motors can be synthesized.