Abstract
A parallel robot with three limbs and five degrees of freedom includes: a static platform as a support base, and a movable platform as a position adjustment, wherein a machining output unit is provided on the movable platform for executing actions; an unconstrained limb group is provided between the static platform and the movable platform, and a constrained limb is also provided between the static platform and movable platform for constraining; the constrained limb moves between the unconstrained limb group, or between extension lines of the unconstrained limb group. The present invention comprises three limbs which are connected to the movable platform through movable joints. The three limbs are connected to the static platform through kinematic pairs. Positional and angular stiffness of the robot can be ensured by proportional constraints on a triangle surrounded by the movable joints as well as a triangle surrounded by connecters on the kinematic pairs. The present invention has the structural advantages of high stiffness and large workspace, which is capable of efficient machining of core components for large-scale high-end equipment.