Fastener

Fastener
nut
An ordinary nut loosens whe the forces of vibration overcome those of friction. In a nut and lock washer combination, the lock washer is used to prevent the nut from losening.
lock washer 锁紧垫片
bolt
screw
cotter pin 开口销
Rivet 铆钉
Shaft
Shafts are mounted in bearings and transmit power through such devices as gears, pulleys 皮带轮, cams凸轮 and clutches离合器. These devices introduce forces which attempt to bend the shaft; hence the shaft must be rigid enough to prevent overloading of the supporting bearings.
For diameters less than 3 in., the usual shaft material is cold-rolled steel cotaining about 0.4% carbon. Shafts are either cold-rolled or forged in sizes from 3 in. to 5 in.. For sizes above 5 in, shafts are forged and machined to size. Plastic shafts are widely used for light load applications.
Bearing
ball bearing
rolled bearing
The concern of a machine designer with ball bearings and roller bearings is fivefold as follows:
1.Life in relation to load

1. Stiffness, i.e. deflections under load
2. friction;

4.wear;
5.noise.
wear磨损
interference 过盈
journal bearing / Sliding bearing滑动轴承
lubricant 润滑油
groove沟，槽
champer 倒角