Time domain series system definition and gear set reliability modeling

• A new type of series system, i.e. time-domain multi-configuration series system is defined, that is of great significance to reliability modeling.
• Multi-level statistical analysis based reliability modeling method is presented for gear transmission system.
• Several system specific reliability models are established for gear set reliability estimation.
• The differences between the traditional series system reliability model and the new model are illustrated.

Time-dependent multi-configuration is a typical feature for mechanical systems such as gear trains and chain drives. As a series system, a gear train is distinct from a traditional series system, such as a chain, in load transmission path, system-component relationship, system functioning manner, as well as time-dependent system configuration. Firstly, the present paper defines time-domain series system to which the traditional series system reliability model is not adequate. Then, system specific reliability modeling technique is proposed for gear sets, including component (tooth) and subsystem (tooth-pair) load history description, material priori/posterior strength expression, time-dependent and system specific load-strength interference analysis, as well as statistically dependent failure events treatment. Consequently, several system reliability models are developed for gear sets with different tooth numbers in the scenario of tooth root material ultimate tensile strength failure. The application of the models is discussed in the last part, and the differences between the system specific reliability model and the traditional series system reliability model are illustrated by virtue of several numerical examples.