ExxonMobil:Premium greases for bearings that can ensure effective relubrication

Rolling element bearings can be broadly categorized as Ball bearings, Cylindrical roller bearings, Spherical roller bearings, Needle roller bearings, and Tapered roller bearings. They find application in a variety of equipment ranging from electric motors to gearboxes and conveyor systems.

Bearings undergo a regimented relubrication program which involves timely lubrication to replace grease that has deteriorated, leaked away, or become contaminated. It takes on the spot know-how backed by expertise to determine the relubrication intervals, owing to the varying conditions these components operate under.

How often one should lubricate the bearings depends on numerous factors. Generally, the smaller the bearing and faster the speed, the less frequent is the interval for lubrication. For instance, ball bearings have a base interval for lubrication, whereas, for a cylindrical roller, the relubrication frequency is almost five times more, relatively.

Having factored in the causes that determine the relubrication intervals and accelerate the process, the immediate requirement to be addressed is the way in which we can mitigate the lubrication challenges. ExxonMobil offers premium greases for bearings that can ensure effective relubrication. These include the following:

Mobil Polyrex™ EM Series: The advanced thickener formulation and proprietary manufacturing techniques of Mobil Polyrex™ EM Series provide improved bearing performance and protection for long electric motor life. These greases are recommended for long-life lubrication of electric motor ball and roller bearings. Key features are:

• Enhanced grease life ensures longevity, high-temperature lubrication of ball and roller bearings, particularly in sealed-for-life applications
• Advanced polyurea thickener increases durability versus conventional polyurea greases when subjected to mechanical shear forces
• Low-noise properties is beneficial for lubrication of ball bearings in many noise-sensitive applications.

Mobilith SHC™ Series: These greases are superior performance products designed for a wide variety of applications at extremes of temperature. Key features are:

• High and low temperature performance enables protection at high temperatures and low torque
• Protection against wear, rust and corrosion reduces downtime and maintenance costs
• Structural stability in the presence of water retrains excellent grease performance in hostile aqueous environments.

Mobilgrease XHP™ 220 Series: These are designed for a wide range of applications including industrial, automotive, construction and marine sectors. Their performance features make them ideal choices for operating conditions including high temperature, water contamination, shock loading and extended re-lubrication operations. Key features are:

• Resistance to water washout and spray-off helps assure proper lubrication and protection even in the most severe water exposure conditions
• Rust and corrosion resistance offer protection of lubricated parts even in hostile aqueous environments
• Broad multi-purpose application provides potential for inventory rationalization and reduced inventory costs.

Relubrication is paramount for ensuring effective performance, protection and long life of rolling element bearings. Using the right lubricant offers benefits of time, maintenance cost, productivity and profitability.

Some factors that determine greasing interval of bearings
Operating Temperature	Environmental Conditions	Adding Grease between Flushing Intervals
Higher temperatures increase a grease’s oxidation rate, doubling it for every 18ºF (10ºC). For example, a bearing operating at 250ºF (120ºC) will require greasing 10 times as often as one operating below 150ºF (65ºC) Grease softens as temperatures increase and may become fluid enough to leak out of the housings	Environmental conditions that subject bearings to contamination, add to the relubrication frequency. Bearings exhibit unusual conditions such as excess heat emission, noise, leakage, vibration, etc. under such conditions.	Many bearings require relubrication with small quantities of grease, between grease flushing intervals. If the seals are in good condition, the quantity of the grease needed may be small and infrequent.