CENTRIFUGAL PUMP HAVING RADIAL THRUST BALANCED

PURPOSE:To prevent acting of an excessive radial thrust to the vanes of an impeller, by forming a fluid passage of a centrifugal pump to have a minimum width at the starting point of volute of a volute chamber and a maximum width at the end of the volute. CONSTITUTION:A fluid passage of a centrifugal pump is formed such that its width (shown as bsp in the drawing) is minimum (bsp) at the starting point of volute of a volute chamber, i.e., as small as possible as may not hinder the flow of work fluid discharged from a centrifugal impeller 1 and maximum (b2+2l) (where l is the thickness of a side plate of the impeller 1) at the end of the volute, i.e., as small as possible as the radial fluid pressure is acted to the impeller 1. Thus, a volute type centrifugal pump having a circular casing 4 with a single tongue portion is so constructed that the product of the width of the fluid passage and the radial static pressure acted to the impeller 1 is constant along the entire length of the fluid passage. By employing such an arrangement, it is enabled to simplify manufacturing of the centrifugal pump, to balance and compensate the static pressure acted to the impeller 1 and to thereby prevent occurrence of extraordinary large radial thrust.