Research On New Power Split Continuously Variable Transmission Of Planetary Ring-Bevel Gear Type

With the development of science and technology and positive response to the national energy conservation and environmental protection policies,mechanical CVT in industrial production and transportation are becoming more and more common.However,its performances of lower transmission power and efficiency as well as the small output torque impose restrictions on applications in large machines.Therefore,this paper proposed and developed a new type of power split continuously variable transmission of planetary bevel gear type which is capable of realizing high power and high efficiency transmission.In this paper,the structure and transmission principle of the original RX type planetary ring taper continuously variable transmission are analyzed in detail.The design method of the geometric dimension parameters of the main transmission parts is described.The positive force and peripheral force of the transmission wheel are analyzed.The calculation formula of the numerical solution of the slip offset of each contact point is put forward by calculating the theoretical formula of the the contact point positive pressure and the long and short half shaft of the contact point ellipse of the transmission wheels.A detailed calculation method for the total friction efficiency of the planetary ring taper continuously variable transmission is obtained.Then,according to the analysis of the relevant theoretical principles,the structural design scheme of the new power split continuously variable transmission of planetary bevel gear type is determined.The design method of the positive pressure adaptive for the new transmission is put forward.In theory,it can reduce the energy consumption of the entire transmission system,indirectly improving the efficiency of the overall transmission,compared with RX-type planetary ring taper continuously variable transmission.Secondly,the power flow and the force of the transmission are analyzed and calculated.Referring to the design method of the geometric dimension parameters of the planetary ring taper continuously variable transmission,the design method of the mean value is used for the first time to deduce the method of calculating the geometric dimension of the transmission of the new transmission.In addition,the calculating formula of the transmission efficiency is deduced.Again,the efficiency diagram of the original planetary ring taper continuously variable transmission is obtained from the calculation of the actual example.The power flow distribution diagram and the total transmission efficiency diagram of the new transmission are obtained from the theoretical calculation.The new transmission efficiency,compared with the planetary ring bevel gears of the CVT,is increased by 10% or more,compared with the original planetary ring taper continuously variable transmission,is an increase of more than 15%.Moreover,without changing the rated power of the planetary ring bevel gear continuously variable power,the transmission efficiency of the power split planetary ring bevel gear continuously variable transmission power can be more than 2.7 times as long as that of the original one.Therefore,the new transmission achieve a high-power transmission.Finally,the new three-dimensional solid component model was modeled on the new transmission.the assembly of all three-dimensional solid parts models and the interference verification of the pre-simulation were carried out.Respectively,the improved planetary bevel gears continuously variable transmission and the new transmission,in the Adams simulation software,were carried out for dynamic simulation analysis.The simulation results of the transmission ratio and transmission efficiency and the results of theoretical analysis have a high similarity.The simulation results show that: the transmission ratio of the planetary ring bevel gear continuously variable transmission changes between 0.06~0.53,which basically reach the demand of the actual application speed range of the transmissions.Although the transmission ratio of the new transmission is only in the range of 0.26~0.38,its transmission efficiency compared with the former,is in general increased by 10% or more.Simulation results verifies the correctness of the theoretical analysis and provides an accurate theoretical basis for the subsequent trial production of the physical prototype.Additionally,it has some theoretical guidance value for studying the same type of transmissions.