roller bearing

roller bearing (plural roller bearings)

1. A bearing in which the load is carried by round (e.g. cylindrical or spherical) elements.
   • 1959, "Steam's Finest Hour" edited by David P. Morgan, Kalmbach Publishing Co.

     In 1930 the proposal of placing all axles of a steam locomotive on roller bearings was viewed so suspiciously that the Timken Roller Bearing Company couldn't even obtain permission to equip an existing engine at its own expense. (It ended up buying a demonstrator loco and equipping that with roller bearings instead.)

• Rolling-element bearing on Wikipedia.Wikipedia
• ball bearing