Durability Investigation of plastic gears

Abstract

Plastic materials can be used for various gears and gear mechanisms due to their qualities, like wear resistance when running dry, low noise, vibration damping, low inertia, low manufacturing cost, etc. However, they also expose with temperature connected problems like rapidly decreasing load, thermal expansion and accuracy of moulded gears. Therefore, it is a challenge to produce gears with adequate accuracy and durability to serve in contemporary mechatronic applications in automotive, in medical equipment and many other industries. Such materials are POM, PA6, PA66, PEEK, reinforced plastic materials, etc. and steel. Proper combination of such materials can result in long and reliable operation of such mechanisms. On the other hand, S-gears offer improved properties in comparison to involute (Egears), which essentially comprise lower contact pressure, less sliding and frictional losses, stronger root and improved oil film when lubricated. The goal is development of advanced power transmission drive components made of polymers. So, a material database, a testing system and testing procedures with varying material combinations and gear pairs according to VDI are necessary to support a designer in proper decisions. Some material properties, especially fillers are presented. Furthermore, testing facilities, gears and some results are discussed.