09-10-2012, 04:16 PM
Gear AND Gear Trains
Gear AND Gear Trains.ppt (Size: 1.98 MB / Downloads: 31)
Gears
A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque
Geared devices can change the speed, torque, and direction of a power source.
Classification of Gears
Parallel Shafts
Uniform rotary motion between two parallel shafts is equivalent to the rolling of two cylinders. They are four types
Spur Gears
It is used where the shaft are parallel.
it consists of straight teeth
Helical Gears
The leading edges of the teeth are not parallel to the axis of rotation, but are set at an angle,
Since the gear is curved, this angling causes the tooth shape to be a segment of a Helix
Intersecting Shafts
The motion between two intersecting shafts is equivqlent to the rolling of two cones are known as Bevel Gear
Straight Bevel Gear
Teeth are straight,radial to the point of intersection of the shaft axes and vary in cross section in their length.