Collaborative Assembly of Hairpin Coils

Established hairpin stators for electric traction motors are made up of a large number of so-called hairpins. To produce these stators, the individual hairpins must first be assembled into an assembly device in order to achieve the desired winding scheme. Manual assembly is prone to errors, while fully automated assembly is characterized by a lack of flexibility and great machine complexity. The new approach presented in this paper is therefore based on the collaborative assembly of the hairpins. A cobot hands the correct hairpins to the operator using an additively manufactued vacuum gripper. The correct positioning of both hairpin legs in the assembly device is ensured by the use of a monitor located under it. The preceding creation of the correct assembly sequence is mostly automated by a collision detection program. Achievable cycle times and possible existing errors are investigated in tests.