GEAR MEASUREMENT

Introduction:

Gears are mechanical drives.

Gears are used to transmit power. Gear in the form of a toothed wheel.

Types of gears:

Spur gear

Helical gear

Spiral gear

Bevel gear

Worm and Worm wheel

Rack and pinion

Gear terminology:

Tooth Profile

Base circle

Pitch circle diameter

Pitch

Addendum

Dedendum

Pressure angle ()

Circular pitch

Clearance(C)

Blank diameter

Face, Flank, Top land

Back lash

Module (m)

Pitch point

Tooth thickness.

Gear errors:

Adjacent pitch error

Cumulative pitch error

Profile error

Cyclic error

Periodic error

Run out

Radial run out

Axial run out

Gear measurement (Spur gear):

Concentricity

Alignment

Hardness

Pith:

1.   Point to point measurement

2.   Direct angular measurement

Run out

Lead

Backlash

Profile:

1.   Optical projection method

2.   Involute measuring machine

3.   Tooth displacement method.

Tooth thickness:

1.   Constant chord method

2.   Base tangent method