GEAR GEOMETRY
BY
Dr Kimutai
12/21/2023 MPE 242 1
,12/21/2023 MPE 242 2
, GEAR GEOMETRY
Introduction
A gear is a toothed wheel that engages another
toothed mechanism by meshing without any
slip(unlike belt or rope), to change speed or the
direction of transmitted motion.
Gear drives are also called positive drives
(constant velocity ratio).
In any pair of gears, the smaller one is called
pinion and the larger one is called gear
immaterial of which is driving the other.
12/21/2023 MPEN 224 3
, When pinion is the driver, it results in step down
drive - output speed decreases and the torque
increases.
On the other hand, when the gear is the driver, it
results in step up drive - output speed increases and
the torque decreases.
Reasons for using gears:
Gears are used either to:
increase or decrease the speed of rotation;
change the amount of force or torque;
move rotational motion to a different axis (i.e. parallel,
right angles, rotating, linear etc.); and
reverse the direction of rotation.
12/21/2023 MPEN 224 4
BY
Dr Kimutai
12/21/2023 MPE 242 1
,12/21/2023 MPE 242 2
, GEAR GEOMETRY
Introduction
A gear is a toothed wheel that engages another
toothed mechanism by meshing without any
slip(unlike belt or rope), to change speed or the
direction of transmitted motion.
Gear drives are also called positive drives
(constant velocity ratio).
In any pair of gears, the smaller one is called
pinion and the larger one is called gear
immaterial of which is driving the other.
12/21/2023 MPEN 224 3
, When pinion is the driver, it results in step down
drive - output speed decreases and the torque
increases.
On the other hand, when the gear is the driver, it
results in step up drive - output speed increases and
the torque decreases.
Reasons for using gears:
Gears are used either to:
increase or decrease the speed of rotation;
change the amount of force or torque;
move rotational motion to a different axis (i.e. parallel,
right angles, rotating, linear etc.); and
reverse the direction of rotation.
12/21/2023 MPEN 224 4
