When it comes to choosing the proper bearing, PBC Linear often refers customers to begin with:
- Precision: The importance of accuracy and repeatability.
- Orientation: How will the system be mounted?
- Speed: Velocity, acceleration, motion profile.
- Travel: Stroke, overtravel, overall envelope.
- Load: End of Arm Tooling (EOAT), cutting or pushing forces.
- Unknown: What could go wrong?
- Duty Cycle: What is the expected lifetime?
- Environment: Hazards, maintenance, contaminants.
- Safety: Safeguards and standards
Within this informal guidance acronym, our experience has shown us that the number one factor in bearing selection is the environment in which that bearing will be used. While the description above for environment is broadly described as hazards, maintenance, and contaminants, the term can cover a range of materials and forces including temperature and humidity, corrosive cleaners and washdown fluids, sticky substances, welding slag, and various types of fine to large particulates. The spectrum of harshness can range from class 1 clean room (cleanest) up to high contamination (dirtiest).
Ask the important questions
There are key considerations to address when establishing how the environment will affect your linear motion system.
- What is the length of travel?
- Where and how will the system be installed?
- What surrounds the system?
- Is there access to perform preventative maintenance?
- If no access to maintenance, does the system require lubrication storage?
Once you have understood the critical needs within your application environment, PBC Linear can provide a wide range of bearing choices for many of those less-than-ideal environments. The following provides details and charts to help match those environmental problems with optimal solutions.
Sticky substances can be found in beverage dispensers, sugar plants, and filling applications, and are handled best by V-Guide rollers. The V-profile channels contamination and clears the raceways, while ball bearings roll and stick. Plain bearings don’t fare well either, allowing sticky substances to fill up the running clearance between the bearing surface and raceway.
Welding cinder or slag can splatter and stick to steel and stainless steel components on V-Guide products, and inhibit travel on ball bearings. Applications such as robotic welders, weld stations, and plasma cutters team up best with plain bearing technology that is combined with our patented FrelonGOLD liner. Its inherent wiping action provides excellent resistance to weld splatter, and has no small raceways to plug. Read our application story on Welding and Automotive Manufacturing.
Dry powder environments are characterized as having fine, powdery particulates, with typical applications that include brick grinding, paper cutting, and gun mounting systems for the military. The video above, Simplicity Linear Bearings vs Bronze Bushing: Dirty Environment Demonstration, provides a simple but enlightening demonstration on the effects of fine particulates on bearings, and the advantages of Simplicity plain bearing over roller bushings within these environments. In the video, our Simplicity bearing is put into a bag with Portland cement. The inherent wiping action is evident, as is the close tolerance between shaft OD and bearing ID that works to keep out contaminants.
Washdown environments are predominately found in food processing applications. Bearing systems have a range of conditions to take into account, from high-pressure sprays and temperature to corrosive detergents. The harshest environments require plain bearing systems with stainless steel, while ball bearings allow contaminents to enter. Read our Linear Motion Design for Washdown Applications white paper for more information on washdown environments, or read our application story Washdown in Bottling Automation.
Large particulates can often contain wood or metal chips, with typical applications including wood milling and foundries. The close fit of plain bearings are ideal as they wipe away debris, while ball bearings will be inhibited by particles filling the raceways. V profiles will also work because of their ability to channel contaminates. Please read our application story on Simplicity in the Woodworking Industry.
Environmental challenges and product solutions
With correct product selection, engineers can overcome most environmental challenges, allowing their linear motion systems to run at a high efficiency rate.
Indoor The indoor application examples below feature these ideal product solutions.
- Cleanroom and Food handling: Plain bearings with Frelon J and aluminum housing, including 316 stainless steel shaft products (Simplicity bearing with Frelon J and S = 316 stainless steel bearing shell a good option).
- Laboratory: All PBC linear products applicable, but dependent upon application.
- General Factory: All PBC Linear products applicable, but dependent upon application.
- Steel Fabrication: Plain bearing and gliding surface products with FrelonGOLD excel in this dirty environment (ceramic coated aluminum shaft near welding).
- Foundry: Plain bearing and gliding surface products excel in this dirty, high-temperature environment.
Outdoor The outdoor application examples below feature these ideal product solutions.
- Rain: Redi-Rail or V-Guide with 400 series stainless steel option, or plain bearings with Frelon J and 300 series stainless steel shafting products.
- Snow: Redi-Rail or V-Guide with 400 series stainless steel option.
- Ice: Redi-Rail or V-Guide with 400 series stainless steel option.
- Sand: Plain bearing and gliding surface products.
- Saltwater (Non-submerged): Redi-Rail or V-Guide with 400 series stainless steel option, or plain bearings with Frelon J and 300 series stainless steel shafting products.
- Saltwater (Submerged): Plain Bearings with Frelon J and aluminum housing, including 316 Stainless Steel shafting products.
- Plain bearings technologies with Frelon liners tolerate frigid cold to extreme hot.
- Ball bearings, cam rollers, and Integral-V products rated 0 C to 80 C (32 F to 176 F).
- PBC Linear actuators rated 0 C to 80 C (32 F to 176 F).
- PBC Linear integrated stepper motors rated -20 C to 40 C (-4 F to 104 F).
Consider selecting these PBC Linear corrosion resistant products when relative humidity levels exceed 70%.
- Gliding surface products or cam roller products, including Redi-Rail or V-Guide with 400 series Stainless Steel option.
- Plain bearings with FrelonGOLD and aluminum housing, including 400 series stainless steel shafting products.
- Plain bearings with Frelon J and aluminum HSG, including 316 series stainless steel shafting products.