| dc.description.abstract | Planetary gear drives have advantages of co-axial input and output shaft, higher power density, etc. However, the load sharing between planets will be unequal, because of presentence of manufacturing and assembly errors. On the other hand, the deformation of components under loading leads also uneven distribution of contact stresses on engaged tooth flanks of gear sets. Therefore, load balancing mechanisms are usually applied in planetary gear drives for solving the problem. Among them, the planetary gear sets with flexible pin mechanism can be designed with more than three planets due to flexibly supported planets, and consequently, the transmitted power can be increased. This mechanism for load balancing has gained more attention for application in gear transmission of windturbines.
The purpose of this study is to analyze and to validate the design of the flexible pin load mechanisms so as to provide detailed information for design. Two types of the flexible pin mechanisms are considered. conventional design and new design with compliant joints. At first, two analysis tools, mechanism design software KISSsoftTM and FEM, will be applied to analyze the individual and interwoven influence of design parameters on the performance of the flexible pin mechanisms. Then, two study cases are considered to explore the performances of the flexible pin mechanisms, each analyzed under the condition of individual loading and integration in a planetary gear set, respectively. A static load experiment is also conducted to validate the results obtained from the individual loading analysis.
The results of influence analysis of design parameter show that the parameters of the the pin are more sensitive to the stiffness of the mechanism than those of the sleeve. It can be also to fullfil the design requirements only by adjusting the design parameters of the pin or the slleve. The analysis results show also differences between the analysis tools KISSsoftTM and FEM: the max. bending stress can be upto 15%, deformation upto 16%. The difference comes mainly from the calculation of the sleeve. The analysis results of the new type design show that the performance of entire mechanism can be also derived directly from the individual analysis results of the pin and the sleeve, respectively. The deformation of mechanism tends to a straight line due to the compliant joint design and it can reduce some unexpected wears.. It is also found that the torsional deformation of the carrier affects also the contact stress distribution strongly. The results from the static loading experiment illustrates also that the stiffness of the bearing is also the important factor for entire stiffness of the flexible pin mechanism, and must be considered while in designing such the mecahnism.
| en_US |