As a machine tool business owner, you face the issue of spindle failure. The cost of the spindle repair and the downtime is a serious drag on your bottom line. Since bearing failure is the most common cause of spindle failures, wouldn’t it make sense to do everything possible to protect the bearings? We will show you how a relatively inexpensive bearing seal technology protects you from thousands in downtime and spindle repair costs.
Industry research shows that 76% of spindle failure is caused by contamination of the bearing, 17% is due to overloading, and just 7% by all other factors combined. With this in mind, Setco’s engineers went to work on the contamination problem.
Ordinary bearing seals use two standard methods to keep out contamination. First is the “rubbing seal” that has contact between the seal and the spindle shaft. This solution causes friction, which produces heat, and heat limits the running speed of spindles. Too much heat and friction leads to spindle failure. The second method uses a small-gap labyrinth design between rotating and stationary parts. This solution has the benefit of no contact (no friction) with the seal, but the non-contact labyrinth design must always have a gap. And regardless of its design, fluids, humidity, and other contaminates find their way into bearing. Both solutions work for some conditions but are far from ideal in preventing contamination and premature spindle repairs, especially in coolant spray and high-contaminant environments.
Setco’s AirShield3 is an ingenious near-frictionless bearing seal that uses pressurized air to keep contaminants out. During spindle operation, pressurized air supplied to the bearing seal is redirected to circulate within an internal pocket around the spindle shaft. The circulating air generates uniform pressure behind a flexible lip, causing the lip to flex away from its contact surface. As the lip flexes, the pressurized air escapes and expels contaminants away from the bearings. When not in use, the lip closes and forms a positive seal that keeps contaminants out. So, when your spindle runs, pressurized air protects the bearings, and when it is not in use, a positive seal closes the bearings to all contaminants.
The beauty is that the pressurized air flowing through the AirShield3 works in many conditions, especially in heavy coolant spray and high humidity environments. The machine’s angular orientation does not matter. Air pressure is maintained regardless of the coolant flow rate or the jet velocity. No matter how the machine rotates, the positive air pressure constantly purges contaminants. Even when the equipment is off, the flexible lip still forms a seal to protect the bearings from contamination.
The AirShield1 was introduced in 1998 and over twenty years of use in the field proves this technology works. Over the years, the technology was further advanced to the smaller AirShield2 in 2001 and the more versatile AirShield3 in 2008. These advancements made the AirShield3 more compact for use in more applications. In all this time, there have been ZERO spindle failures caused by bearing contamination when an AirShield was installed, and air purge was properly applied. To back this claim up, we offer a 3-year warranty against spindle contamination when an AirShield is properly pressurized.
The cost of a Setco AirShield3 is a tiny fraction of the cost of a new or rebuilt spindle. AirShield3 bearing seal technology protects you from thousands of dollars in downtime and spindle repair costs. The AirShield3 cartridge design adapts easily to most spindles and comes in 32 sizes ranging from 25 to 250mm inside diameter.** AirShield is patented technology available only through Setco. To find out how to have the AirShield3 as part of your new or rebuilt spindles, contact your Setco representative or contact our Customer Service team.
** AirShields 125mm and larger use AirShield2 technology due to their large size and carry the same 3-year warranty as AirShield3.