Flank-load-carrying-capacity of oil-lubricated thermoplastic gears for power transmission

• Applicant: Professor Dr.-Ing. Karsten Stahl
• Subject Area: Engineering Design, Machine Elements, Product Development
• Term: from 2018 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 393025460

The use of plastic gears for power transmitting gearboxes is gaining more and more importance. Low density and high damping characteristics are plastic specific advantages. Temperature dependent material parameters and load carrying capacity, however, restrict the scope of application. Running in dry condition may cause melting of the plastic teeth and therefore failure of the whole gearbox. Therefore the knowledge of the tooth temperature is of high importance for plastic gear development. Current calculation methods such as VDI 2736 are derived from steel standards and therefore neglect plastic specific material characteristics. In the scope of a DFG-project, several thermoplastic materials have been investigated regarding tooth load-carrying-capacity. Modified calculation approaches to calculate tooth root stresses have been developed. In the current research project, adequate thermoplastic materials are now investigated regarding tooth flank-load-carrying-capacity under lubricated conditions. Experimental investigations for the determination of the tooth temperatures as well as runs in back-to-back testing will be performed. In addition theoretical studies using numerical and analytical approaches will be conducted and validated using experimental results. The objective is to extend the current state of knowledge regarding flank-load-carrying-capacity for plastic gears and to develop a safe and complete calculation method.

• DFG Programme: Research Grants