WEB EXCLUSIVE: Next-generation Volkswagen diesel engines will benefit from a multi-functional crankshaft cover that reduces weight and cost. It was jointly developed by DSM Engineering Plastics (U.S. office in Brimingham, Mich.) and automotive component manufacturer KACO of Japan. The cover is made of DSM’s biobased EcoPaXX nylon 410.
The new cover incorporates integral seals of PTFE and LSR (liquid silicone rubber) as well as various metal inserts. It will be used on VW’s new MDB modular diesel engine platform, implemented across its Audi, Seat, Skoda, and VW brands. Compared with aluminum covers, system costs for the EcoPaXX cover are reported to be considerably lower, thanks in part to the use of an integrated, fully-automated production cell at KACO. Weight has been reduced considerably as well.
Thermoplastic crankshaft covers are still uncommon, with nylon 6 and 66 being the favored materials. The very tight dimensional specification of the VW version, as well as the high loads it has to withstand, made the challenge of producing the new cover particularly severe. The partners met the challenge, thanks to nylon 410’s mechanical properties at elevated temperatures and excellent toughness, together with KACO’s skill in integrating static and dynamic seals into the parts.
Says Andreas Genesius, head of project management at KAKO, “The part comes out of the injection molding cell ready to be assembled onto an engine block. No trimming is necessary at all.” KACO uses the production cell to mold the crankshaft cover and integrate two separate seals: The first, in PTFE, is placed into the mold by a robot, and EcoPaxx is overmolded onto it. The second, in LSR, is then molded directly into the part using a two-component injection process.