Rock and other aggregates are some of the most essential materials in nature. Everywhere you look – roads, bridges, and buildings – are made of these critical materials that make up the very foundation of our society. At Regal Rexnord, our motion control solutions products back this essential industry as it continues to grow, and our products help support an efficient process for these resources to be mined.
Challenges at the Quarry
There are many demanding applications and challenges within a quarry environment that pose obstacles. Rollway spherical roller bearings help address one of the most challenging areas in the mineral processing environment. Vibratory screens play a crucial role in separating rock materials by size once broken down by specialized crushing equipment. Within these machines, shafts run across the width of the shaker screen designed with attached counterweights. Laying across the top of the shafts is a screen fitted with slots that represent the target size of the material which will run through the machine, allowing material of the correct magnitude to pass through and sending the rest to be further crushed. When cranked up, a motor drive spins each of the counterweight fitted shafts at an extremely high rate of speed, some designs being engineered to run in excess of 2,000 RPM.
On each side of the machine, a heavy-duty spherical roller bearing tolerates the brunt of having to combat friction in a nasty environment. Many times, mounted in an OEM housing on a sleeve with a locknut and washer, these bearings will face extremely high temperatures from the high rates of speed - resulting in large amounts of thermal expansion. They will also be battling large impact loads as chunks of rock slam down on top of the screen inside of the machine. All the while, seals integrated into the housing will be fighting off the ingress of water, rock dust, and other heavy particulate – some of which will inevitably make its way to the bearing itself.
Rollway Bearing Enhancements
The harsh conditions of vibratory screens were a primary driver in adopting a highly engineered Rollway spherical roller bearing with enhancements, specifically for this mining process. At the heart of the design is a special machined brass cage, designed to pilot on the outer ring raceway to accommodate the centrifugal forces through the bearing and provide proper roller guidance. Brass is a durable material to handle the impact and shock loading which vibratory screens are accustomed to. The outer ring guided cage allows for lubrication flow in the most critical areas within a bearing and maintaining the needed lubricant film between the roller and outer raceway. Equipped with a modified C4 radial internal clearance, Rollway spherical roller bearings sport clearances in the upper 2/3 of the C4 clearance range to accommodate the radial thermal expansion, as well as shaft and housing fits, in this demanding application. Likewise, the OD and ID tolerances are reduced to allow best fit with the respective housing and shaft.
Rollway bearing cage types, including VS & MA for vibratory applications
Who is Rollway?
Since 1908, Rollway bearings have been a building block of customers' cornerstone products. From trolley cars in the 1910s to tank bearings in WWII - Rollway has a storied history of supporting advancements within heavy industry. The aggregate market is a great example of the strength of our bearing portfolio and how it continues to help customers around the world, no matter how difficult the environment.
If you'd like to find out how Rollway bearings can help your application, schedule time to talk with an expert.
Dan Geraghty has been in the bearing industry since 2015 in various sales engineering, business development, and commercial operations roles. He joined Regal Rexnord in 2020, and currently supports the Industrial Components division as a Business Development Manager for unmounted bearings, partnering with our sales team to support some of Regal’s largest OEM customers, both virtually and on-site. Dan also works on pricing, forecasting, and inventory management for Regal Rexnord’s unmounted bearing brands.