Master's thesis discusses the welding of segments of electric motor stator core with Nd:YAG and fiber laser. The goal of research was selection of optimal welding parametrs with wich we can reach sufficient mechanical strength of welded joints with minimal cogging torque of electric motor. In theoretical part is described the theory basis about brushless direct current electric motor, its construction, operation and characteristics. Then is presented literature overview about welding of laminated stator core and theory basis about laser and laser welding. Experimental work contains descriptions of welded material and construction of stator core, descriptions of welding equipment and selection of welding parametrs and description of researches for quantitative evaluation and comparsion of welded joints quality and cogging torque of electric motor. Based on results of preliminary test, mechanical test, metallographic examination, hardness measurements and cogging torque measuremets and minimal input energy per unit length of weld the optimal welding parametrs for welding of segments of electric motor stator core are selected. The results of cogging torque measurements showed that the influence of the welding parametrs on cogging torque are negligible.
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