Potential for Lightweight Design of a Hybrid Conncecting Rod for Automobile Applications

Using a split hybrid connecting rod developed by Daimler-Benz, the industrial applicability in the engine is verified. The connecting rod consists of several components such as a compression-stressed shank and a tension loop made of CFRP, a split crankshaft bearing and a small connecting rod eye made of titanium.

Beyond weight savings the use of these materials offers specific advantages like

• good damping properties of CFRP reducing noise emission of the engine
• high bending strength and stiffness of titanium.

A prerequisite for making optimum use of the low oscillating mass of the hybrid connecting rod is a lighter design of the entire engine through weight reductions of attached parts. Due to high material and fabrication costs, mass production of split hybrid connecting rods is not practicable at present, whereas unsplit versions can successfully be utilized in high efficiency engines.