An assembling method of an air cylinder assembly used for a double-cylinder rotary compressor

The invention discloses an assembling method of an air cylinder assembly used for a double-cylinder rotary compressor. The double-cylinder rotary compressor comprises the air cylinder assembly and a crank shaft passing through the air cylinder assembly. The air cylinder assembly comprises two air cylinders disposed in the vertical direction and a separation plate between the two air cylinders. Each air cylinder is provided with a piston. The crank shaft comprises two subsidiary crank shaft sections. Each subsidiary crank shaft section comprises a subsidiary shaft section, a subsidiary eccentric shaft section and a subsidiary middle shaft section which are connected in sequence along the axial direction. The assembling method includes S1) a step of coaxially assembling one of the two air cylinders to one side of the separation plate; and S2) a step of coaxially assembling the other air cylinder to the other side of the separation plate in the step S1). According to the assembling method, only one aligning machine is needed to perform aligning and assembling of the separation plate and the two air cylinders, and the method is simple in process, easy in assembling, and capable of ensuring assembling quality of the air cylinder assembly and meeting requirements of large-scale production.