A model-based design approach to redesign a crankshaft for powder metal manufacturing

Abstract: A crankshaft is a component which is used to convert a reciprocating movement into rotating or vice versa. Through the past years classical manufacturing techniques did not leave space for a new approach regarding manufacturing this component. Powder Metallurgy provides a manufacturing technique which can revolutionize this procedure and make it more economical and more efficient. In order for this to be achieved, the crankshaft must be produced in different pieces. Webs, counter-webs and journal shafts must be produced individually and assembled together. The main challenge in this thesis is to understand if the crankshaft’s counter webs could be manufactured all in the same pieces or in as less pieces as possible. This thesis deals mostly with the technical requirements and proposing a new modular design. A kinematic-kinetic analysis is performed by using the values from the existing crankshaft which has been scanned and converted into a CAD model. The numerical values from the kinetic-kinematic analysis in Matlab are compared with a MBS model from Adams. Then the balancing of the crankshaft is analyzed and it is investigated how the counterweights should be arranged in space and what should be the mass and the geometrical properties of them. From the component’s design specifications, several models are generated and evaluated with the Pugh matrix. The original and the new proposed models are compared as far as concern the mass, center of mass, mass moment of inertia and natural frequencies.