| dc.description.abstract | The planetary gear train has the advantages of high speed ratio, high power to weight ratio, compact structure, and coaxial input and output axes. Hence, it is widely applied in various mechanical transmission systems such as automation equipment, vehicle transmission, wind power generation, etc. In order to achieve a larger speed ratio of the planetary gear drive, a multi-stage planetary gear drive is generally employed with combination between the individual stages to fullfil the design requirements. The combination can be achieved by connecting the annular gear, sun gear, and carrier.
The first step for design of of the multi-stage planetary gear drive is analysis of the complete mechanism after the structure is determined. In general, the analysis methods for planetary gear drives are derived from the relations of the structure. Hence the analysis of multi-stage planetary gear drives will be laborious due to structure diversification. The aim of the thesis is thus to propose a design approach for multiple stage of planetary gear drives based on modularization concept. At first, the structure coding scheme is determined from the connection relations between each stage. Various matrix equations are therefore established based on the coding scheme so as to calculate quickly the speeds, torques, and complete mechanical efficiency of the planetary gear train. With this analysis, the basic gearing design parameter can be obtained for the required design specification. Afterwards, a design catalog for various connection types of ring gears, sun gears and carrier of the planetary gear train is proposed for design aid. The proposed design approach from basic design to detialed design can incrase the efficiency for designing the planetary gear train.
In this study, a differential type two-stage planetary gear drive was analyzed and designed according to the proposed approach. It was manufactured and assembled. The measurement of the contact pattern of the gears was also conducted. It can be inferred from the measured contact patterns that the running of the planetary drive is not smooth due to a larger eccentricity of the carrier. This inference is in good agreement with the measurement result of the components on a 2.5D Measuring Machine. | en_US |