Thermoplastic high performance composite gears

This paper describes the development and testing of gears based on polyetheretherketone (PEEK) and endless carbon fibers. Behind these results is a research project funded by INNOSUISSE with the aim of developing plastic gears with which much higher strengths than previously available gears can be achieved. In principle, two types of gearwheels are investigated which differ in their manufacturing method: icotec’s injection molding CFM (Composite flow moulding) process and milled gears (GP) made of composite plate materials. The wheels produced in the CFM process have very good static strength. However, the expected performance in the running tests could not be achieved due to insufficient dimensional accuracy from the CFM process. Comparative tests with GP gears were able to confirm the expected service life. For example, the tests with a line load of 60 N/mm were terminated after approximately 106 load cycles, since the wear was limited to the run-in amount and no failure was to be expected. During dry running tests in a range of 105-106 cycles a load > 129 N/mm was run