6b-2

keys are used

• only in circumstances which do not call for frequent separation of the parts.

• transmit a drive at considerable mechanical power from a shaft to a hub, or vice versa

• to fit the radius of the shaft

A spring is

• an engineering component which when deflected by a force tends to return to its unloaded shape.

• work by resisting externally applied torque.

• to apply a fixed load throughout their life

High Duty Springs subject to

• resisting externally applied torque.

• rapidly reciprocating loads

• : support the journals of shafts and axles.

Torsion springs work by :

• support the journals of shafts and axles.

• resisting externally applied torque.

• rapidly reciprocating loads

- Bearings are used to

• forces that act radially to the shaft axis.

• resisting externally applied torque.

• support the journals of shafts and axles.

Bearings typically have to deal with two kinds of loading :

• weight

• shear and torsion.

• radial and thrust.

LUBRICATION of the bearings requirement for ---- working life of bearings is adequate lubrication.

• short

• long

Synthetic bearings are often lubricated with What?

• water

• oil

• grease

Ball bearings have a very----- starting resistance and are suitable for high rotation speeds.

• low

• high

• in between

Roller bearings are used

• if the occurring stresses are too severe for ball bearings.

• distinguished into radial- and axial bearings, depending

• becomes necessary to change the direction of control