Centrifugal pump

A centrifugal pump comprising:

• a motor that has a shaft, and
• an impeller that is engaged with an end portion of the shaft such that a rotation of the impeller relative to the shaft is limited, a nut fixing the impeller to the shaft, the end portion of the shaft being located on a first side of the shaft, wherein
• the impeller includes
• a main panel that is engaged with the shaft,
• a plurality of passage walls that extend from the main panel in an axial direction,
• a side panel that is in contact with end surfaces of the plurality of the passage walls that face away from the main panel, the side panel having an inflow opening at a radially center part, and
• a fluid passage that is defined by two of the plurality of passage walls which are adjacent to each other in a circumferential direction, the two adjacent passage walls being located between the main panel and the side panel, the fluid passage communicating with the inflow opening,
• the impeller is configured to rotate to intake a fluid into the fluid passage through the inflow opening, a pressure of the fluid taken into the fluid passage being increased by a centrifugal pressure, the fluid being discharged radially outward of the impeller, and
• the side panel includes an engagement portion configured to be engaged with a fixation jig that limits a rotation of the impeller during fixing the impeller to the shaft by screwing the nut.