Gears, Gears and More Gears2).pdf · 2020-04-26 · Gears Gear Speed :- Calculation A motor gear...
Transcript of Gears, Gears and More Gears2).pdf · 2020-04-26 · Gears Gear Speed :- Calculation A motor gear...
Gears, Gears and More Gears
What is a gear?
A gear is a wheel with teeth that mesh together with other gears.
Gears change the• speed• torque (rot. force)• direction of rotating axles.
Different types of gears
Spur gears
Belts & PulleysBevel gears
Idler gears Worm gears
Gear Motion
If this were my “Driver
Gear,” it would be
causing the motion
Thus the “Driven Gear”
would be compelled to move
Where Do You Find a
Simple Gear Train?
Two meshed gears
will rotate in
opposite directions.
Watch gears
11. Found in:
– Watch
– Sewing Machine
– Motor
Where Do You Find a
Simple Gear Train with
Idler?
Two meshed gears will rotate
in opposite directions.
An Idler Gear allows the
drive and driven gears to
rotate in the same direction.
8. Found in - Paper Transport Rollers
Gears
Generally, the Gear Ratio is
calculated by counting the teeth of
the two gears, and applying the
following formula:
Gear ratio = Number of teeth on driven gear
Number of teeth on driver (drive) gear
Gear Ratio
Gear Ratio….continued
Driver (Input) Driver (Input)
Driven (Output)
Driven (Output)
GearsGear Ratio - Calculation
A 100 tooth gear drives a
25 tooth gear. Calculate the
gear ratio for the meshing
teeth.
Gear ratio = Number of teeth on driven gear
Number of teeth on driver gear
Gear ratio = driven 25 = 1
driver 100 4
This is written as 1:4Or .25
Important
Calculations
Work Done = Force x Distance moved in the direction of the
force
Power = Total Time Taken
Total Work Done
Efficiency % =Power Output
Power Input
Friction: - Resists the movement of one surface over another
X 100
Efficiency = Mechanical advantage
Velocity ratio
Gears Gear Speed :- Calculation
A motor gear has 28
teeth and revolves at 100
rev/min. The driven gear
has 10 teeth. What is its
rotational speed?
Speed of driven gear = Number of teeth on driver gear x 100
Number of teeth on driven gear
Speed of driven gear = driver = 28 x 100 = 280 rev/min
driven 10
28 teeth,
driver
10 teeth,
driven