Corrosion-resistant magnet pump

Abstract

Disclosed is a corrosion-resistant magnet pump comprising a front casing, a rear casing provided behind the front casing with a partition wall interposed therebetween, a rotary shaft extending from the front casing into the rear casing and supported by a bearing provided at least in the partition wall, an impeller fixed to the rotary shaft within the front casing, a driven magnet drivingly connected to the rotary shaft within the rear casing and a drive magnet provided outside the rear casing and drivingly rotatable by a motor, the portions of the pump to be exposed to a liquid being made of a corrosion-resistant material, the impeller being fitted around the front end of the rotary shaft and fastened to the rotary shaft by an impeller nut screwed on the front end, the magnet pump being characterized in that the impeller comprises a ceramic insert in the center of the impeller and the remaining portion of corrosion-resistant synthetic resin around the insert, the insert having a rear end face projecting rearward and serving as a thrust bearing face, the partition wall having a thrust bearing face opposed to the rear end face of the insert, the impeller nut and the rotary shaft being made of a corrosion-resistant material.