Kinematics and performance analysis of rudder blade fixed hydraulic spherical joint

In view of the problem of driving method for the spherical motion mechanism, a new type of hydraulic drive spherical joint with two degrees of freedom was proposed. The joint mechanism used a full cycle rotating motor and a rudder blade swing motor as drive, adopted a measuring system of slide support frame, and could achieve a full rotation. The oil circuit design programs for the two driving motor were given respectivly. The reasonable sealing method was adopted in different parts of the mechanism. Based on the mechanism theory, the forward and inverse kinematics equations and the velocity Jacobian matrix were derived and the singular configuration of the mechanism was found. Through the analysis of dexterity performance index of the mechanism, the workspace was found by simulation when the mechanism was in a good performance. The spherical joint mechanism has the following characteristics, compact structure, high motion accuracy, large load, and it can complete the omni-directional output.