Abstract A pump impeller, especially useful in the pumping of corrosive and abrasive liquids, includes a unitary blade-shaft member of a material such as a corrosion resistant vitreous or ceramic material, which is impracticable for threading or other such shaping operations or has insufficient strength to withstand normal forces on threads or other such elements thereof. To provide for affixation to means for rotating the impeller in a pump, a threadable shaft extension is employed, inserted into and cemented in place in a hollow portion of the blade-shaft member and threaded or otherwise formed or machined at its other end for connection with suitable driving means. By making the blade-shaft member so that the corrosion-resistant shaft portion is long enough to extend past a seal, contact of the pumped liquid with the impeller is limited to the corrosion-resistant part thereof. Also disclosed are pumps and motor-pump combinations including the mentioned impellers, as well as methods for the manufacture of the impellers.
A corrosion-resistant centrifugal pump impeller comprising a unitary blade-shaft member of nucleated glass which is a substantially crystalline material derived from glass by heat treatment effected in the presence of nuclei seeded into the glass, about which crystals grow at a nucleating temperature, said glass being comparatively brittle or poor in tension so that it is impracticable to thread the shaft portion thereof, such shaft portion including a longitudinally extending walled internal opening along the length of the shaft, and a shaft extension which is of threadable metal, such shaft extension comprising a portion for insertion into the blade-shaft member internal opening and a threaded portion external to said opening, by the threads of which latter portion the impeller blade-shaft member and the shaft extension thereof are connectable to rotating driving means, and cement or adhesive contacting the walls of the internal opening of the impeller blade-shaft member and the inserted portion of the shaft extension and cementing or bonding them together.
Claim 2
Dependent Claim
162 words
A corrosion-resistant centrifugal pump impeller comprising a unitary blade-shaft member of nucleated glass which is a substantially crystalline material derived from glass by heat treatment effected in the presence of nuclei seeded into the glass, about which crystals grow at a nucleating temperature, said glass being comparatively brittle or poor in tension so that it is impracticable to thread the shaft portion thereof, such shaft portion including a longitudinally extending walled internal opening along the length of the shaft, and a shaft extension which is of threadable metal, such shaft extension comprising a portion for insertion into the blade-shaft member internal opening and a threaded portion external to said opening, by the threads of which latter portion the impeller blade-shaft member and the shaft extension thereof are connectable to rotating driving means, and cement or adhesive contacting the walls of the internal opening of the impeller blade-shaft member and the inserted portion of the shaft extension and cementing or bonding them together.
Claim 3
Dependent Claim
114 words
A corrosion-resistant centrifugal pump impeller according to claim 1, wherein the portion of the shaft extension for insertion into the blade-shaft member internal opening and the longitudinally extending walled internal opening in the bladeshaft member are matching cylinders having a regular clearance between them for a cement, the cement is a flexible, permanent cement, the external surface of the insertable portion of the shaft extension is knurled or otherwise roughened to provide improved fastening of said portion to the walls of the internal opening in the blade-shaft member and the external surfaces of the shaft portion of the blade-shaft member and the threaded portion of the shaft extension are of substantially the same diameter.
Claim 4
Dependent Claim
28 words
A corrosion-resistant pump impeller according to claim 2 wherein the cement is a flexible, permanent cement selected from the group consisting of epoxy resin, phenol-formaldehyde and rubber cements.
Claim 5
Dependent Claim
77 words
A corrosion-resistant pump impeller according to claim 1 wherein the impeller includes a rod portion of nucleated glass which is integral with the blade-shaft portion thereof and the insertable portion of the shaft extension is a hollow cylinder which fits the annular opening between the rod and the wall of the impeller shaft internal opening and which is cemented to the nucleated glass walls of the rod and the blade-shaft member internal opening on both sides thereof.