A division of Parker Hannifin, located in Otsego, Mich., was custom building machines for its own use, manufacturing brass fittings. Two such machines were rotary-index style and required 10 spindles that could withstand the large amounts of cutting fluids and chips associated with that design.
With recommendations from Setco, a spindle design, manufacture, and rebuild company, Parker decided on the company's belt-driven ProMetrix model spindles, which include the AirShield system. It eliminates spindle-bearing failure by keeping out coolant, condensation, contamination, and chips.
"We've had problems with spindles that incorporate the old method of pressurizing along with standard bearings and seals," says Mike Mehler, manufacturing engineer at Parker Hannifin. "There is a lot of fluids and chips to contend with on a rotary-index machine, so when we found out the Setco spindles included the AirShield, we considered it a bonus," he adds.
Each spindle on the rotary-index machines runs on a 7-hp motor, and the shop drills holes up to 1 1 /4 in. in diameter in the brass fittings. In the running mode, air enters the spindles equipped with AirShield, and an internal-porting arrangement equalizes and disperses supplied air. Equalized air then gradually escapes by gently lifting a Viton seal from its contact surface, creating a near-frictionless design.
When the spindle stops, the air purge is off, and the machine is in washdown condition. The Viton lip seal closes, forming the equivalent of a rubbing seal to prevent contaminates from entering the spindle. Unlike other such systems, AirShield does not inhibit spindle bearing lubrication, is non-contaminating, requires only standard clean/dry shop air, and is maintenance free.
Setco Sales Co.