Spark erosion machining of miniature gears: a critical review

This paper presents a review of previous work conducted as regards to the machining of miniature gears by spark erosion machining (SEM) process and its variants. Miniature gears are key components of various small devices. Their proper function requires the selection of an appropriate manufacturing and/or finishing process that will deliver the required fit for purpose quality. Spark-erosion-based machining processes have a proven track record to impart the relevant quality characteristics and to minimize the number of operations required. This paper commences with an introduction to miniature gears before outlining the spark erosion machining of gears. Details as regards to previous efforts conducted on machining of these gears by SEM-based processes are presented before selected future research trends, directions and avenues for possible future research are offered. This paper focuses exclusively on SEM of miniature gears even though it is noted that similar research work on macrogears is also limited. This review paper aims to facilitate an overall view of all the available literature on spark erosion machining of miniature gears in a single article, to promote the technology and to provide a road map to researchers for making efforts towards exploring these technologies further.