The utility model discloses a machine structure for centrifugal pump, seal the seat and fix the cover and establish at the epaxial axle sleeve of pump including quiet ring, rotating ring, machine, on the axle sleeve fixed cover be equipped with with spacing its the interior rotating ring seal receptacle of rotating ring, the machine seals seat clearance cover and establishes on the axle sleeve, the machine seal be provided with between seat and the axle sleeve with spacing its the interior quiet ring seal receptacle of quiet ring is provided with axial spring in the quiet ring seal receptacle, the spring will quiet ring supports and leans on on the rotating ring, the rear end that the machine sealed the seat is provided with radial spacer, the spindle nose loop that is equipped with with pump shaft axial swing joint overlaps in the shaft shoulder department of pump shaft. The utility model discloses a quick -witted structure is sealed the change by bi -polar face machine and is sealed for a single -end machine, eliminates the warpout moreover and seals the leakage problem that rubs pair fracture and cause, has reduced the influence of particulate medium to sealed of sound ring, and the life cycle that has prolonged the pump has reduced the spare parts expense and the cost of overhaul.