Crankshaft transmission structure and machining method

The invention relates to the technical field of mechanical transmission structures, and discloses a crankshaft transmission structure and a machining method.The crankshaft transmission structure comprises a driving shaft, an eccentric shaft and a connecting shaft, and a connecting rod assembly slidably connected into a compression groove of an air cylinder unit is installed on the connecting shaft; the driving shaft is rotationally connected to the crankcase, a gap is formed between the crankcase and the driving shaft, and sealing gaskets are arranged at the two ends, located in the gap, of the driving shaft to form a lubricating liquid cavity; a bidirectional thread is arranged on the driving shaft located in the lubricating liquid cavity, a first liquid passing opening is formed in the end, corresponding to the lubricating liquid cavity, of the crankcase, and a second liquid passing opening is formed in the threaded connection position, corresponding to the bidirectional thread, of the crankcase. The first