Magnetically driven centrifugal pump

Claim 1

A magnetically driven centrifugal pump comprising a housing having a space provided therein, a split plate for dividing said space of said housing into a rotor chamber and an impeller chamber, an inlet and outlet connected to said impeller chamber, first and second bearing members fixed respectively to the inner wall of said rotor chamber and to said split plate, a shaft rotatably supported by said first and second bearing members respectively at its rearward end and intermediate portions and having its forward end portion projected into said impeller chamber, an internal rotor fixed to said shaft within said rotor chamber and having a plurality of first magnets, an external rotor disposed outside said housing and having a plurality of second magnets magnetically connected to said first magnets, a driving means for rotating said external rotor, an impeller fixed to said shaft within said impeller chamber, fluid intake passage means for guiding into said rotor chamber a fluid pumped by said impeller, resticting means for reducing the pressure of the fluid passing through said passage means, and cooling passage means for permitting the fluid sent from said rotor chamber to pass through said first and second bearing members thereby cooling said bearing members, the inner wall of said rotor chamber which is faced to the rearward face of said internal rotor being provided with first guide vanes extending toward said shaft, said first guide vanes defining first guide passages therebetween, said first guide passages being opened to the rotor chamber at their lengthwise sides and having such a configuration as to cause fluid rotating jointly with the internal rotor to positively flow through said first guide passages toward the shaft.