POWER TRANSMISSION REFERENCE GUIDE
Rotary bearings
for power transmission
B
earings are internal machine components that are crucial to motion applications. They reduce friction between moving parts by giving a surface something on which to roll rather than slide. Rotary bearings consist of smooth rollers or metal balls and inner and outer surfaces (races) against which the rollers or balls travel. These rollers or balls carry load carrier and let axes spin freely. Bearings typically encounter radial and axial load. Radial loads are perpendicular to the shaft, and axial loads occur parallel to the shaft. Depending on the application, some bearings must withstand both loads simultaneously.
What’s the difference between ball and roller bearings? Because the contact area between balls and races is so small, ball bearings excel in light to moderate loads. The small areas of surface contact also minimize friction-generated heat, so ball bearings work well in high-speed applications. In contrast, roller bearings have cylindrical rollers. They’re common in applications such as conveyor belt rollers because their rolling elements make more surface contact with their races — so handle larger loads with-out deforming. Their shape also allows for a moderate amount of thrust load, as weight is distributed across cylinders instead of spheres.
12
DESIGN WORLD — MOTION
Bearings — Power Transmission HB 05.19 V3.indd 12
5 • 2019
Dodge food-safe ball bearings withstand caustic and high-pressure washdowns with an IP69 rating without an end cover. That’s helpful in food and beverage applications requiring sanitary machinery. The bearings also include Hydro armor sealing with a stainless-steel flinger and four contact lip seals — to prevent water and contamination ingress.
motioncontroltips.com | designworldonline.com
5/14/19 8:27 AM
