Quick switching structure of single-stage centrifugal pump and multi-stage centrifugal pump and working method of quick switching structure

The rapid switching structure comprises a mechanical seal support, the mechanical seal support is fixed to a motor middle cover, a motor end cover is arranged on the front side of the motor middle cover, a motor front cover is arranged on the front side of the motor end cover, and a main shaft is arranged in the mechanical seal support; a shaft sleeve, a second-stage impeller, a friction ring A, a first-stage impeller and an inducer are sequentially sleeved on the main shaft from back to front; the motor front cover is provided with a first adjusting device used for controlling the first-stage guide vane outlet position to be communicated with or disconnected from the motor end cover channel A, and a second adjusting device used for controlling the first-stage guide vane outlet position to be communicated with or disconnected from the second-stage impeller inlet position. The invention further discloses a working method of the rapid switching structure. According to the rapid switching structure of the single