- Crank mechanism The
main element in the crank which is rotated and mounted on
the frame and is so designed that it can perform complete
revolutions/rotation, and its motion is transmitted through
the coupler rod to the lever arm, like wide rotatably mounted,
but not performing complete revolutions. Other alternative
is, instead of being connected to a lever, the coupler may
be attached to a sliding element like a piston, in a steam
engine or internal combustion engine.
- Gear Mechanism This
type of mechanism transmits circular motion from one shaft
to another, usually in conjunction with a change in rotational
speed and torque. Usually in a gear mechanism, the transmission
is effected by the meshing of gear teeth, but in the friction-gear
mechanism this positive drive is replaced by frictional
contact of wheels or rollers.
- Pulley mechanism Connection
between the pulleys on the respective shafts is effected
by flexible elements like belts, rope, etc..
- Cam mechanism A cam
plate mounted on a frame is driven and thus moves a lever
or slider which thus performs a desired predetermined motion
depending on the shape of the cam, for example like valve
control mechanism in an internal combustion engine.
- Ratchet mechanism This
serves to arrest a motion or to produce an intermittent
circular rotation in the driven element. The pawl allows
the ratchet wheel to rotate in one direction only preventing
rotation in the opposite direction by engaging with the
specially shaped teeth on the wheel.
- Screw mechanism when
the screw spindle is rotated, the element attached to the
nut will move in longitudinal direction of the screw. If
the nut is rotatably mounted in the frame of the mechanism
and driven, the screw spindle will move longitudinally.