It is not uncommon for pump repair shops
to repair a wide variety of size and shaped impellers.
Accordingly, the bore sizes and corresponding tolerances
also vary from part to part. Because of these
variations, shops have to machine a new arbor for each
impeller, which adds significant cost to the balancing
operation. Inventory, storage and quality control of
numerous balancing arbors adds to the total cost of the
process
Mechanically expanding tooling arbors are the solution
to this dilemma. Mechanically expanding tooling is very
easy to use and saves a significant amount of time for
loading and unloading the impellers. The tooling
consists of a tapered arbor and a mechanically expanding
collet. The gripping force comes from the collet as it
slides up the tapered shaft to fit into the bore. A
tooling package consisting of five individual arbors
covers a bore range of several inches. To utilize
these arbors most efficiently, a hard-bearing,
permanently calibrated balancing machine should be used,
eliminating the need for recalibration of soft-bearing
machines.
