Evonik has developed a PEEK moulding compound (polyetheretherketone) with very good tribological properties and high durability for use in the harsh environment of an internal combustion engine to replace metal gears. The series component is manufactured by IMS Gear SE and is used by Mercedes-Benz in various models.
Mass balancers ensure the smooth running of an internal combustion engine by reducing the vibrations caused by the pistons on surrounding structures. Mass balancer gears come into contact with engine oils and are therefore exposed to maximum temperatures of up to 130°C. Until now, only metal gears have been used in this environment.
With Vestakeep PEEK 5000 G, Evonik offers a suitable material with high resistance and high performance to replace these metal gears. In addition to the required vibration damping, plastic gears offer an additional advantage of high resistance to mechanical and tribological stress. Compared to conventional metal gears, they have lower friction losses and are significantly quieter. The lower mass moment of inertia saves energy. Gears made of this material are manufactured by injection moulding and are said to eliminate the extensive reworking that was previously necessary when using metal.
With the use of its own gear testing rig, Evonik supports development activities during close coordination with the customer. "We can generate specific material data that can be used to optimally design the gears made of our high-performance plastics," says Philipp Kilian, head of tribology development high performance polymers at Evonik, describing the advantages. "We can test in a temperature range from -20°C to 260°C, both in dry and lubricated condition."
Dr. Steffen Kanzler, who is responsible for Vestakeep for transportation at Evonik, said: "Our customers receive qualified support from the material selection and computer assisted simulation up to the technical implementation by our application technology team."
Thanks to their high temperature, chemical resistance and high ductility, the high-performance polymers of the brand can replace metal components, for example, to enable sophisticated lightweight construction applications.