PEEK gears replace metal in automotive applications

PEEK gears replace metal in automotive applications

Plastic gears are gradually replacing traditional metal gears in numerous technical applications because they are lighter and quieter, have good dry running properties, are low friction and low wear, and can be manufactured efficiently. Compared to gears made from engineering plastics, products made from high-performance plastics such as polyether ether ketone (PEEK) are typically more stable in terms of mechanical, thermal and chemical properties, and are therefore able to extend load limit values.

Convincing mechanical properties and chemical resistance of PEEK

When developing high-performance polymers for gears, the different mechanical and thermal properties and tribological requirements should be reconciled as much as possible with the stresses involved. Certain material modifications can have an adverse effect on gear performance. For example, additives that are sometimes used to improve wear resistance or reduce friction may negatively affect the dynamic mechanical behavior of gears if they become a source of defects or cracks (depending on the particle properties and their potential to bond to the plastic matrix).

The high-performance plastic PEEK has many advantages over engineering plastics such as polyoxymethylene (POM), Pa6 and Pa66 for use as a gear material. In particular, it can transmit high loads even in high-temperature environments. Because of its almost negligible water absorption and low shrinkage and post-shrinkage, molded parts are dimensionally stable and, based on the molecular structure of the thermoplastic material, it is also extremely chemically resistant. These properties are particularly important when gears are lubricated with motor oil or transmission fluid, which is a corrosive environment for many plastics.

Compared to other engineering plastics, PEEK's extremely high mechanical and thermal stability has made it successful in gear applications.

Other advantages of PEEK include excellent frictional wear characteristics, particularly low wear and friction coefficients. The latter ensures energy savings in both dry running and lubricated conditions.

Compared to metal gears, special plastic peek gears can effectively damp vibration, but also has a high mechanical and frictional pressure resistance. These advantages allow peek gears to be used in automotive transmissions, engineers have made the impossible possible, and through a series of tests and evaluations, peek has been able to be perfectly applied to this harsh operating conditions.