A Synthetic Approach of Power Screw Drive Failure Modes

Power screw drives are machine components that convert a rotative motion into a translation one with usually high efficiencies and very high "Load to Torque" ratios, thus, often in very compact volumes. Usually made of hardened and grounded carbon steels, "bearing steels", low to medium alloyed rolled and/or hardened steels they are also manufactured from non-metallic materials (f.e. Bronze Rg7) but also, in the recent years, out of "high tech engineered polymers" (PA, PI, PVDF, ...). As machine members subjected to various loading histories, speeds and accelerations, temperature and environmental influences, they may exhibit different failure modes involving fracture, corrosion, fatigue (superficial and volumetric), wear and some other miscellaneous effects linked with their structure or the environment they are working in. A synthetic exhaustive review of all potential simple modes of failure, essentially, based on a property identification, coupled with industry failure cases, seen in practice, has been performed. Power screw drives being used in a wide range of industry sectors and machineries (Heavy casting or rolling devices, packaging units, aerospace, pharmaceutics & medical, water work, ...) preliminary goal of this review was to confront Designers with what they have to check for while designing, this to prevent any types of failures. Even so, this review can also be used by Failure Analysts to be aware of some of the potential issues seen in industry. After a short overview of main materials, heat & surface treatments exploited, a practical synthetic matrix of potential failure modes will be presented.