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 .