Foreign object debris (FOD) including dirt, dust and oil can material cast-off, can all cause damage to turbine engine bearings. FOD can be introduced to the oil system by using inappropriate oil can opening tools and oil filling equipment not suited for the task.
Even though turbine engine bearings are made of hardened steel and designed to operate for a long time in a FOD-free environment, they are surprisingly susceptible to damage from FOD. When FOD enters the engine oil system, bearing life shortens dramatically.
The reason is the very high contact pressures that are present in the small contact zones between the bearing rolling elements and the raceway. Pressures of around 200,000 psi between the ball and the raceway are not uncommon. Over-rolling contaminant particles with such high contact pressures results in bruises and dents in the bearing raceway with raised edges around. The raised edges are like the edge of a crater.
The harder the particle, the sharper the dent and the higher the stress concentrations at the edges. In severe cases a “comet tail” might form on one side of the crater. This is from the ball hitting the edge of the crater and then going back out smoothing that edge along the way.
Every time the rolling element passes over the dent, contact pressure increases at the raised edge of the dent. The indentation thereby creates higher stress and initiates fatigue. This fatigue leads to premature spalling. The spall starts as a surface crack originating at the back end of the indentation.
Hard particles such as chips and metal fragments from inappropriate oil can opening can also get wedged in the softer cage material and create grooves in rolling elements. The “grooving” leads to improper rolling-contact and shorter bearing life.
How much oil can material cast-off is introduced to the inside of a turbine oil can? Read the newsletter here.
TheCanKey is the only FOD free oil can opener on the marked. It is tested and certified by Saybolt Laboratories not to leave any debris whatsoever in the oil can during the opening process.
Use TheCanKey turbine oil can opener to ensure not to introduce FOD to your oil system when servicing or filling oil. It is an easy, proper and effective way to prevent FOD. Using TheCanKey FOD free oil servicing tools will ultimately save costs and improve overall safety and performance of the engine.
Read more about TheCanKey FOD free oil service tools here: www.TheCanKey.com
