In allusion to solve the issue of fault diagnosis for bearing and other rotatory machinery. a technique based on fined-grained multi-scale Kolmogorov entropy and whale optimized multi-class support vector machine (abbreviated as FGMKE-WOA-MSVM) is proposed. Firstly. vibration signals are decomposed by fine-grained multi-scale decomposition. https://www.sahmbuffy.com/product-category/3-6v-lithium-batteries/