10. CENTRIFUGAL CLUTCH
As the engine rotates, the inside assembly of the
centrifugal clutch starts rotating but drum remains
stationary and no power is transmitted. At lower
speed, the centrifugal force produced is not
sufficient to overcome the spring force. So the
clutch remains disengaged. But as the speed
increases, the centrifugal force also increases and
now the centrifugal force becomes greater than
the spring force.
As the centrifugal force becomes greater than the
spring force, this allows the sliding shoes to move
outward against the spring and get engaged with
the inner surface of the drum.
The drum starts rotating and transfers the rotating
power from the engine to the driven shaft of the
transmission.
When the load on the engine increases, its speed
decreases and disengages the clutch.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32. Working of an Overdrive:
The working of an overdrive depends on the same principle as any of the other sun and planetary or epi-cyclic gear
arrangement like automatic gearbox i.e the fixing of any of the sun or planetary or annulus changes the power
output of the drive.
Overdrive Disabled –
When overdrive is disabled the input shaft passing through the sun gear rotates the sun gear which in turn rotates
the constantly meshed planetary gears and then these planetary gears rotates the annulus and direct drive (same as
input shaft rpm) is obtained.
Overdrive enabled-
When driver enabled the overdrive, the sun gear becomes fixed which mean the annulus is now rotated by the
planetary gears or in other words now the input from the input shaft is now transferred through the planetary gear
to the annulus due to which overdrive is obtained, which means now the output shaft rotates with the higher rpm
than input shaft due to the higher reduction ratio of planetary gears and annulus.
