Aluminum magnesium alloy transmission shell capable of exhausting and reducing pressure

The invention relates to the technical field of transmissions, and discloses an aluminum magnesium alloy transmission shell capable of exhausting and reducing pressure, which comprises a transmission assembly, the transmission assembly comprises a transmission shell and a power shaft arranged at the output end of the transmission shell, a driving groove is formed in an inner cavity of the transmission shell, and a driving disc is arranged on one side of the outer surface of the power shaft. A first magnetic block is arranged on the outer surface of the driving disc, the top face of an inner cavity of the top cover downwards extends to an inner cavity of the exhaust pipe and is provided with a limiting column capable of limiting and stretching, a rotating pipe is arranged around the axis of the exhaust pipe, and the upper end of the rotating pipe upwards extends to the lower end of the top cover and is provided with a scraper with the side wall attached to the outer surface of the exhaust pipe. The problem tha