| Underwater operation equipment is an important carrier for the development of deep-sea space resources.Natural seawater is used as the working medium of the hydraulic system of underwater operation equipment,simplifying the hydraulic system,realizing the green deep-sea equipment,and theoretically solving the problems of pollution caused by the oil-water mutual seepage of the hydraulic system during deep-sea operations and the decrease of equipment reliability.The main operation function of underwater operation equipment is inseparable from the cooperation of the deep-sea manipulator.When the three adjacent joint axes of the manipulator wrist intersect at one point,that is,the elbow of the manipulator adopts a swing form,the manipulator has a closed solution,which can be controlled in real time and accurately positioning.However,there is no water hydraulic swing cylinder as the elbow joint of the manipulator at home and abroad.A water-hydraulic swing cylinder for deep-sea manipulators is invented in this paper,therefore,its deep-sea adaptability,angle error and other key issues are studies.Finally,the development and testing of the prototype is completed.The main research contents are as follows:1)Aiming at the problems of deep-sea ultra-high pressure environment and seawater with low viscosity,strong corrosiveness and suspended sand,a water hydraulic swing cylinder with a working chamber and a lubrication chamber separated.The lubrication chamber is lubricated with oil to solve the wear and lubrication of the screw pair problem.The water hydraulic swing cylinder adopts a combined structure of one-stage screw transmission and spline-oriented positioning,and the transmission efficiency is 20%higher than that of two-stage screw transmission.After comprehensively considering the overall size,angle error and structural strength of the screw pair,it is determined that the water hydraulic swing cylinder has a higher power density and transmission efficiency when the nominal diameter of the screw pair is 36 mm and the helix angle is about 41°.2)The effect of the deformation of the spiral pair of the water hydraulic swing cylinder in the deep sea environment on the rotation angle of the water hydraulic swing cylinder is studied,and the angle error caused by the deep sea high pressure environment is merely 0.15°.The compression rate of the sealing ring elastomer is 3.35% under deep sea high pressure,and it is verified that the designed sealing structure can meet the requirements of deep sea work,and has no effect on the rotation angle of the water hydraulic swing cylinder.The angle error caused by the assembly gap of the water hydraulic swing cylinder is 1.2°.Through the improvement of the assembly process,the angle error reduce to 68% of the original.Finally,the various factors of the angle error of the water hydraulic swing cylinder is analyzed,and it is found that the angle error caused by the screw pair clearance and the assembly gap accounts for 73% of the total angle error of the water hydraulic swing cylinder.The angle closed-loop control system is used to improve the positioning accuracy of the water hydraulic swing cylinder.3)The hydraulic swing cylinder for water outlet was developed,the performance tests of the prototype on water surface at 15 MPa and in deep sea were completed.It was concluded that the water hydraulic swing cylinder has good sealing performance,the starting pressure is 0.5 MPa,the maximum output torque is 350 N·m,the maximum rotation angle is 300°,and the angle error is about 3°,and the relationship between the working pressure of the water hydraulic swing cylinder and the output torque is obtained.Through the closed-loop control of the angle of the water hydraulic swing cylinder,it is indicated that the positioning accuracy of the water hydraulic swing cylinder system is±0.1°.The water hydraulic swing cylinder can provide non-continuous rotation power for deep-sea precision water hydraulic drive operations. |
PDF Full Text Request