Abstract: In order to develop new type of forging manipulators, the method and principle of type synthesis for forging manipulators based on GF set is proposed. The concept and characteristics of GF set, which contains translational item and rotational item that rotational axes are intersects at one point, is introduced. The influence of translational item on rotational axis is studied. The theorem of rotational axis position subjected to the translation is presented and proved. Then the union and intersection rules for GF set based on the theorem are proposed. The motions of forging manipulator are decomposed into main motions which include lifting, pitching, and the translation about the forward direction of forging manipulator, and secondary motions which include yawing and lateral motion. According to the two kinds of motions and GF set, serials of forging manipulators are proposed. From the type synthesis procedure of forging manipulator perspective, the method with GF set is an intuitive approach that provides a novel method for type synthesis of forging manipulators.

Key words: Forging manipulator, GF set, Rotational axis position, Type synthesis