| The tooth profile design and machining error of planetary roller screw directly determine the transmission performance.In this paper,the tooth profile design,process manufacturing,error detection analysis,theoretical calculation and performance detection of planetary roller screw are studied based on a project of a research institute in China Shipbuilding.The tooth profile with good contact characteristics is designed based on the meshing transmission theory,and the core processing technology of planetary roller screw is broken through.The machining error is controlled to improve the processing quality of products,and the transmission performance of domestic planetary roller screw is promoted.The specific research contents are as follows :(1)Based on the knowledge of meshing transmission,the meshing equation of spiral surface is established,and the tooth shape of screw,roller and nut is designed considering the contact point position of thread tooth,machining error limit and axial clearance requirement.Considering that the gear in the planetary roller screw pair is prone to tooth breakage,the gear pair is modified to increase the tooth thickness,so as to improve the gear strength and further improve the service life of the planetary roller screw pair.The forming method of grinding wheel is analyzed,which provides reference for the design and manufacture of grinding wheel and surface dressing.(2)According to the working characteristics of planetary roller screw pair,the machining accuracy,selection of materials,design of process flow,determination of surface heat treatment method,design of cutting tools and process parameters are determined based on the basic principles of controlling the machining accuracy,surface strength and good transmission performance of screw thread.After the machining of each part is completed,the thread machining accuracy is detected,the machining error is traced and analyzed,and the error control method is put forward,which provides reference for the subsequent process optimization and process parameters improvement,and promotes the machining quality of planetary roller screw pair.(3)Based on the machining error,assembly error,deformation error and installation error of planetary roller screw pair,the travel error model and transmission efficiency model of planetary roller screw pair are established.Then the causes of each single error in the theoretical model are analyzed and its influence on the axial travel error is calculated,which is used as the evaluation index of the transmission performance of planetary roller screw pair.(4)The travel error,friction torque and transmission efficiency test of planetary roller screw are carried out.The test proves that the transmission performance of planetary roller screw is improved after improving the process.After measuring the error of the test bench and the installation error of the screw pair,the calculated values of the travel error and the transmission efficiency model are corrected,and compared with the experimental values,the validity of the theoretical model of the transmission performance is verified.According to the structural size of the planetary roller screw pair,the machining accuracy level and the actual operating conditions,the travel error and the transmission efficiency can be effectively estimated combined with the theoretical model proposed in this paper. |
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