The Research Of Screw Rotarycylinder For Underwater Manipulator

The screw rotary cylinder is a special kind of cylinder which can translate the hydraulic energy into torque energy.It has the characteristics of big and precise rotational angle,compact structure and huge output torque,so it is adapt for hydraulic machine's rotary motion.This design of screw rotary cylinder is used for ROV's mechanical arm to make it turn around.ROV need to do many different motions to complete different tasks.Designing a mechanical arm which can turn over 360° will largely improve ROV's underwater work capability.So it is meaningful to do the research of screw rotary cylinder.This paper has mainly done these following works:At first.Design the double-screw spiral structure according to the demanding of rotary angle and output torque etc.The first and mainly work of designing is calculating nominal diameter and screw pitch.Then check out every parameter to ensure the quality of the design.Use the SolidWorks software to 3-D modeling designing components and assemble these parts to check if there is interference.Then research the dynamics analysis of double-screw rotary structure.find out the relationship of these designing parameters and build Kinetic equation.then research the rule of designing parameters' influence to the screw rotary cylinder,and optimize design structure.Certiflcate the mechanical hand can complete 360 degree rotation when the piston stroke is 73mm.The transmission efficiency of the mechanism is studied,which is mainly influenced by the mechanical transmission efficiency and the volume efficiency.Then use ANSYS software to do Static analysis by finite element method,simulate the situation of maximum torque and get stress and strain distribution for shaft and piston.Test structure strength by comparing the demands of stress and strain.When the cylinder is simulated,the stress and strain and deformation of the system under the maximum pressure are tested,and the performance is appropriate.At last,two oil film in the inner space of the cylinder are analyzed,they are meaningful to the efficiency and service life.Choose the most suitable oil film by comparing different films'performance through flow field analysis.