The invention relates to a three-degree-of-freedom parallel-connection mechanical
wrist which comprises a base, a movable platform, a constrain driving
branch chain used for connecting the base with the movable platform, and two driving
branch chains which are same in structure, wherein the two ends of the three
branch chains are symmetrically distributed in a regular triangle shape together with the base and the movable platform; the constrain driving branch chain consists of two revolute pairs and a driving sliding pair, so that a
resilient packet ring (RPR)-type series-connection structural branch chain can be formed; the constrain driving branch chain is connected with the base and the movable platform by virtue of the revolute pairs; the two driving branch chains which are completely the same as each other respectively comprise a universal pair, a movable driving pair and a spherical hinge, so that an uninterrupted power supply (UPS)-type series-connection structural branch chain can be formed; and the two driving branch chains are respectively connected with the base by virtue of the universal pairs, and connected with the movable platform by virtue of the spherical hinges. The three-freedom parallel-connection mechanical
wrist has the advantages of being strong in
carrying capacity, good in stability, large in
work space, high in flexibility, simple in structure, fewer in moving branch chains, hard to interfere, free from self micro-movement, high in accuracy, easy to control since a driver is close to the base, etc.