ball-bearing
ball-bearing — noun
1. A set of tiny, hard steel balls placed between two surfaces of a machine so that
A set of tiny, hard steel balls placed between two surfaces of a machine so that one part can rotate or slide against the other with much less friction.
Valentina replaced the old ball bearings in her bicycle's rear wheel hub.
collocation: replace ball bearings
After greasing the ball bearings, Ravindra tested the conveyor belt system.
The skateboard moved much more easily after we put new ball bearings in the wheels.
A grinding noise from the fan meant the ball bearings inside were worn.
- bearing
a broader category; ball bearings are one type of bearing, along with roller bearings and plain bearings
- roller bearing
similar in function but uses short cylinders instead of balls to reduce friction
文法句型
ball bearing(s) + in + [machine part]
用法筆記
Ball bearing is most often used in the plural form (ball bearings) even when referring to a single mechanical assembly, because the component contains many small balls.