Roller Bearings

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 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
cylindrical-roller-brg2

  • 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
needle-roller-brg

  • Roller thrust bearings
    • Handle high thrust loads
    • Typically found in gearsets used for car transmissions between gears or between the housing and rotating shafts
roller-thrust-brg