What Is An Industrial Trunnion?

Trunnions & Rotary Kilns

Published on December 13, 2012 by: Kimberlie Stewart

By general definition, a trunnion is a cylindrical protrusion used as a mounting or pivoting point. The term is also used to describe the wheel on which a a rotating cylinder is positioned. A trunnion design is used for rotary kilns used in the cement and lime, paper and pulp and similar industries.

About Trunnion Bearings

A trunnion bearing is an industry-specific bearing mechanism that allows a piece of equipment to rotate without any restrictions, yet still remain fastened to the equipment. For example, different types of machinery suited for different industries – such as cement, lime, paper, food processing or waste – all utilize different types of machinery that incorporate different types of trunnion bearings within those machines. These types of industrial machines can include kilns, coolers, dryers and calciners. Trunnion bearings can be likened to hip joints, which allow your legs to move freely while still remaining attached to your body. In heavy industry, trunnion bearings are attached to shafts. These shafts allow the devices to execute highly precise tasks without damaging the structures of the machines during the process.

Trunnion Roller vs. Trunnion Bearing

Some industries use trunnion rollers instead of trunnion bearings to attach shafts to machines. Just like their name suggests, trunnion rollers are perfectly spherical machinery parts that allow the shafts to spin to accomplish specialized tasks. Some machines can utilize both rollers and bearings to accomplish different sub-tasks within one main task, or to achieve varying tasks for completely unrelated jobs.

Importance of Keeping Your Machinery's Trunnion Bearings Working Properly

During normal, low-temperature conditions, your machinery's trunnion bearings will most likely be able to bear regular the normal wear and tear imposed on them during use. However, once the running of your machinery exceeds 125 degrees F, normal industrial petroleum lubricants can cause carbonaceous residues and low viscosities to surface. Consequently, these substances will overload your trunnion rollers and bearings, and initiate repeated mechanical problems and breakdowns. These distressing circumstances can ultimately cost thousands upon thousands of dollars in repair or replacement costs.

The only sure way to protect your machinery from trunnion bearing or roller failure is to consistently apply high-temperature industrial lubricants. These specially formulated lubricants will lower your machinery's bearing and roller temperatures, increase your production time, reduce your maintenance and repair costs and extend the life of your equipment indefinitely.

Trunnion Tires (Tyres) & Rollers

A rotary kiln or dryer that is positioned within a trunnion rests on rollers, bearings and/or tires (aka tyres). These parts allow rotation of the kiln or dryer however to minimize friction these parts must be lubricated to compensate for operating temperatures that can exceed 600 degrees Farenheit. The preferred lubrication for a rotary kiln or dryer is a solid graphite block or composite metal-graphite block lubricating bar. These lubricating bars are manually inserted into the equipment and produce a slick and relatively even graphite coating on moving parts. Lubricating graphite block products are a specialized lubricant that are available from a graphite block distributor such as Anion Corporation in Atlanta, Georgia.

Related Rortary Kiln Components

There are many other parts within a rotary kiln or dryer which need maintenance, lubrication, and infrequent replacement. These parts or services include trunnion and tire resurfacing, tire resurfacing, kiln mill bearing lubrication, kiln roller lubrication, and the periodoc cleaning and painting. Repairs to trunnions, rotary kilns and dryers should be performned by a professional industrial equipment repair company.