Roller bearings typically have a higher radial loading capacity than ball bearings. However, they also usually have a lower thrust loading capacity. They use rolling elements which are cylindrical in shape, such as the Cylindrical Roller Bearing, the Needle Roller Bearing, and the Thrust Bearing as opposed to a ball, giving a larger surface contact area which aids the greater loading capacity as it reduces the concentration of internal loads. If a roller bearing is loaded at an angle as opposed to directly radially, it will fail very quickly.
Roller Bearing Applications
- Contact surface is generally rectangular when load is applied.
- Higher rotational torque than for ball bearings, but rigidity is also higher.
- Higher load rating than ball bearings.
- Support heavy radial loads.
- Support limited axial loads.
- Lower speed ability than ball bearings due to the increased friction.
Types of Roller Bearings
Cylindrical Roller Bearings
- Low-friction, high-radial load capacity, and high speed capacity
- Point of contact between the bearing and the race is a line, load is distributed over a larger area allowing the bearing to handle a greater load
- Applications such as conveyor-belt rollers
Needle Roller Bearings
- Elongated cylindrical rolling elements with small diameters
- Only radial loads
- Used in applications where radial space is limited.
- Generate high amounts of friction
- Used at low speeds and oscillation motions
Roller Thrust Bearings
- Handle high thrust loads
- Typically found in gearsets used for car transmissions between gears or between the housing and rotating shafts