DSM, along with automotive component specialist KACO, has developed a lightweight crankshaft cover that uses EcoPaXX, DSM’s bio-based polyamide 410, for the latest line of diesel engines developed by the Volkswagen Group.
The cover incorporates integral seals in PTFE and liquid silicone rubber (LSR), as well as various metal inserts. It will be used on Volkswagen’s new MDB modular diesel engine platform, implemented across its Audi, Seat, Škoda and VW brands.
Compared with covers made of aluminium, system costs for the EcoPaXX cover are said to be considerably lower, thanks in part to the use of an integrated, fully automated production cell for the component at KACO. Weight has been reduced considerably too, since the EcoPaXX grade is 45% less dense than aluminium.
DSM says that 70% of its EcoPaXX polyamide 410 is derived from renewable resources, and the polymer is certified 100% carbon neutral from cradle to gate. In the production stage, KACO moulds the crankshaft cover, and at integrates two separate seals: the first, made of PTFE, is placed into the mould by a robot, and EcoPaXX is over-moulded onto it; the second, made of LSR, is then moulded directly into the part using a 2K process.
Thermoplastic crankshaft covers are still uncommon, with polyamide 6 or 66 being the favoured material.
Andreas Genesius, Head of Project Management at KACO said: “The part comes out of the injection moulding cell ready to be assembled onto the engine block. No trimming is necessary at all. By taking a holistic approach to automotive part design and production, we are contributing to sustainable technological progress without any compromise on part performance or competitiveness.”
Fibre orientation, the number and position of gating points, and the design and integration of the various inserts have been optimised to minimise warpage and ensure tight seals between the cover and the engine block and oil sump, says DSM. The cover is also resistant to the tightening of bolts fixing it to the engine block and the sump (each of which are built to different tolerances), as well as from tools used to fix the position of the FEAD (Front End Accessory Drive) belt.