Applications suitable for grease. Grease
and oil are not interchangeable. Grease is used when it is
not practical or convenient to use oil. The lubricant choice
for a specific application is determined by matching the
machinery design and operating conditions with desired
lubricant characteristics. Grease is generally used for:
(1) Machinery that runs intermittently or is
in storage for an extended period of time. Because grease
remains in place, a lubricating film can instantly form.
(2) Machinery that is not easily accessible
for frequent lubrication. High-quality greases can lubricate
isolated or relatively inaccessible components for extended
periods of time without frequent replenishing. These greases
are also used in sealed-for-life applications such as some
electrical motors and gearboxes.
(3) Machinery operating under extreme
conditions such as high temperatures and pressures, shock
loads, or slow speed under heavy load. Under these
circumstances, grease provides thicker film cushions that
are required to protect and adequately lubricate, whereas
oil films can be too thin and can rupture.
(4) Worn components. Grease maintains
thicker films in clearances enlarged by wear and can extend
the life of worn parts that were previously oil lubricated.
Thicker grease films also provide noise insulation.
