Composite centrifugal impeller for slurry pumps

A composite impeller suitable for use in pumps handling hot, highly abrasive slurries and having a drive shaft, said impeller comprising:

• a disk shaped backplate comprising an axial forwardly extending hub section and an axial opening extending through said hub for securing said backplate to said drive shaft, said backplate being constructed from material comparable in thermal expansion to said drive shaft;
• a cover plate having a forwardly extending flange concentric to said hub, said cover plate being constructed from material comparable in thermal expansion to said drive shaft,
• a radially segmented insert forming the working surfaces of said impeller sandwiched between said backplate and said cover plate, said segmented insert being constructed from high temperature and wear resistant material and having forwardly extending sections extending between and entirely covering said hub and said flange for matably engaging said hub and said flange and for protecting said hub and said flange from abrasive wear;
• bonding material joining said insert to said backplate and said cover plate, said bonding material being constructed from brazing alloy which at the operating temperature of said pumps allows said insert to float between said backplate and said cover plate to accomodate the differences in thermal expansion between said backplate, said cover plate and said radially segmented insert, yet retains sufficient tensile strength to transmit driving torque to said radially segmented insert.