The key point of condition monitoring and fault diagnosis of gearboxes is a fault feature extraction. The study of fault feature detection in rotating machinery from vibration analysis and diagnosis has attracted sustained attention during past decades. In most cases determination of the condition of a gearbox requires study of more than one feature or a combination of several techniques. This paper attempts to survey and summarize the recent research and development of feature extraction methods for gear fault diagnosis, providing references for researchers concerning with this topic and helping them identify further research topics. First, the feature extraction methods for gear faults diagnosis are briefly introduced, the usefulness of the method is illustrated and the problems and the corresponding solutions are listed. Then, recent applications of feature extraction methods for gear faults diagnosis are summarized, in terms of industrial gearboxes. Finally, the open problems of feature extraction methods for gear fault diagnosis are discussed and potential future research directions are identified. It is expected that this review will serve as an introduction summary of vibration feature extraction methods for gear faults diagnosis for those new to the concepts of its applications to gear fault diagnosis based on vibratio
