Bearings and Lubrication Explained

Protecting bearings from dust and water.

Protecting bearing from dust. Protection methods like labyrinth rings, rubber seals, felt seals, and shaft mechanical seals are described. The choice of the appropriate shaft seal and seal configurations to protect against dust ingress is critical. Numerous shaft seal designs suited to dusty conditions are reviewed.

Grease - the right type of lubrication in bearing.

The classification, selection, and application of greases. Greases are designed for specific applications and if used in the wrong service they will not be effective. Compare the properties of greases and check those used in your equipment are suited to the service.

Agitator shafts steady bearing problems.

Vertical tank agitator bearings are required to take both radial and thrust loads. To protect the gearbox it is common practice to install intermediate bearings on the shaft. If these bearings are exposed to the process vapors then special care is needed to protect them from contamination and ensure adequate lubrication.

Angular contact bearing use.

They are used on shafts that encounter axial forces or combined loads (both axial and radial forces). Examples are centrifugal and helical rotor pump shafts and helical and worm gear shafts in gearboxes. Their design only permits axial forces in one direction. For alternating axial loads, they must be installed as a bearing set to accommodate the forces from both directions. When set back to back, and less so when set face to face, they act to stiffen the shaft and handle larger bending moments such as overhung components or high midpoint shaft loading.

Spherical roller bearing use.

These bearings are popular because they can take very heavy loads and are self-aligning. Their design allows them to take combined loads in both the radial and axial directions acting together.

Converting bearings from oil bath to greased lubrication.

The conversion of shaft bearings on a basket centrifuge from oil bath to grease lubrication involved changing the method of shaft sealing. Roller bearings can be lubricated with oil or grease. The use of grease has distinct advantages in some applications.

How o-rings work.

Properly designed o-ring grooves and properly installed o-rings stop the passage of pressurized liquids or gasses. O-rings are made of elastomeric materials such as rubbers and plastics. Flexibility while being deformed under pressure is their greatest sealing advantage. They deform under pressure and then return back to their original shape once the pressure is removed.

Oil - how clean does it have to be?

Clean, dry oil can extend equipment life between failure up to 8 - 10 times the normal operating life. Timken, the bearing manufacturer, reports that reducing water levels from 100 PPM (parts per million) to 25 PPM increases bearing life 2 times. British hydraulics research indicates that if solids contamination with particles larger than 5 microns (0.005 mm or 0.0002") is reduced from the range of 5,000 - 10,000 particles per milliliter of oil to 160 - 320 particles, the machine life is increased 5 times.

The 6 secrets of trouble-free lubrication success.

Lubricants can only reduce friction if their immediate environment sustains their lubricating properties. Once the operating conditions are known a suitable lubricant with the right properties can be used. When the lubricant is in place it is necessary to maintain the environment and the machine to the specified design standards and protect it from changes to the design conditions. There are six key factors to address for trouble-free life where grease or oil lubrication is used on machinery.

Lubrication cleanliness & filtration.

When oil in gearboxes become contaminated there is a rapid loss of bearing operating life. It is critical that metal particles, dirt, sand, oxidization products, etc be removed from the oil before they gouge and tear-up the finely tolerance machine parts. Oil replacement, contamination prevention and oil filtration are common practices religiously adopted by the best in the equipment reliability management business. This article explains the fine requirements for successful contamination control to ensure long trouble-free equipment life.