The invention relates to a rotor for a centrifuge, in particular for purifying lubricating oil in an internal combustion engine, wherein said rotor is rotatably mounted in the centrifuge housing and is provided with an impurity trapping element, the rotor or the impurity trapping element thereof are made of a plastic material and remote deflecting baffles arranged in said impurity trapping element can be removed from the centrifuge housing. The invention is characterized in that the inventive rotor or the impurity trapping element thereof comprises a lower part and a top part, lower deflecting baffles are provided in the lower part, top deflecting baffles are provided in the top part, the lower and top parts are congruently welded to each other, the deflecting baffles are incorporated into the welded connection and through openings, which connect the chambers of the impurity trapping element delimited by said deflecting baffles to each other in a fluid permeable manner, are embodied in at least one part of the deflecting baffles on one or two sides of the welded connection or on the plane thereof.