Carrying Capacity Study Of The Spirit Of The Planetary Transmission. Linear Actuator

Precision planetary transmission of electromechanical actuator(EMA) in aerocraft is an important transmission components which required volume, mass minimization, the carrying capacity maximization, integrated performance optimization. As extremely harsh Technical requirements, high reliability and short-term overload is several times of common planetary transmission, precision planetary transmission design theory is a key technology bottlenecks, there is no complete design specification. This paper focuses on the load characteristics of precision planetary transmission, designed to increase carrying capacity through research to find out the law, provide a theoretical basis for the rational design.Firstly, the precise theory of planetary transmission based on analytical method is established by comparison of different calculation methods on root bending strength and tooth contact strength; the tooth root stress on compression side cannot be ignored in the final analysis, and the formulas of the tooth root strength on compression is established; research suggests that the tooth root stress on compression side cannot be ignored, thus the formulas of the tooth root strength on compression is established.Secondly, five special mesh positions are fixed based on the theory of gear mesh, and the deformable body model considering friction and the fillet of root under the rated load, twice rated load, thrice rated load is analyzed to compare the stress, some suggestions are listed to enhance the load capacity on high overload condition.Thirdly,.the influence of errors on planet load sharing is researched. The manufacturing errors and assembly errors is listed and analyzed, and a simplified discrete model is established, The accuracy of the discrete model is quantified by comparing its predictions to the predictions of the finite element model. Two models is used to quantify the influence of errors on gear bending stresses, and on planet loads on the condition of high over load.In the end, the influence of ring gear rim thickness on the stress, strain and planet load sharing on the condition of high over load is analyzed by using the finite element model of the whole planetary transmission which provide a theoretical basis for the design.