Type synthesis of tire building drum with scalable drum-shoulder

This paper deals with the innovative design of a tire building drum with large axial and radial scalable ratios. Type synthesis of the tire building drum with scalable drum-shoulder is studied by dividing the drum into internal and external drum-shoulder mechanisms according to movement requirements and driving modes. The possible structural forms of these two types of mechanisms are obtained by adding independent limbs. On that basis, the relationship of limb structural constraint screws is analyzed based on screw theory, resulting in the feasible structure of each limb subject to structural requirements, so that feasible initial configurations of the two types of mechanisms are obtained by combining the limbs. Thereby, the regenerative motion chain method is employed to obtain all the configurations with the same topological characteristics as initial configurations, during which 11 types of internal drum-shoulder mechanisms and 6 types of external drum-shoulder mechanisms are synthesized, respectively, and 726 types of tire building drums with scalable drum-shoulders are combined. Finally, the feasibility of the method proposed is corroborated with the CAD simulation model of one synthesized tire building drum.