Gear Inspection
To optimize the gear performance, an accurate and precise inspection of
gears is a crucial factor. The maximum life of any drive train is solely
dependent on proper inspection and the subsequent repair procedures. If the
gears are not properly inspected it is obvious that the gear will eventually
fail and easily destroy other accessories also in the drive train system.
The technician who is in charge of the gear inspection should be thoroughly
aware with all types of gear wear and damages.
A Basic process
to an accurate gear inspection
For a proper identification of the damaged areas during an
inspection operation, a magnifying glass, a very strong and clear
light source (sunlight is perfect), and a reflector made up of
clean, white and non-glossy sheet of paper is to be used for best
results. The white paper is able to reflect the light properly onto
dark surfaces.
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Gear Inspection Procedure
Outlined here is a few steps that must be used in the Gear inspection
process.
- Before embarking on an inspection mission it is imperative that the
gears are cleaned thoroughly.
- Checking teeth surfaces, this can be done using marking color and
tape.
- A very careful inspection is to be done for the entire surface area
of the gear. This is done to check pitting, spalling, cracking etc.
Other than these gears are prone to other type of damages, which also
need to be taken care of. Inspection is also essential for every gear
tooth. As it is quite likely that only one tooth can be damaged.
- The next step is a very attentive inspection of the gear bore. This
is to be done with a bright light. To cite an example Planet gear
bearing bores are very much sensitive to speeds and high loads. So is
the need for a careful inspection.
- The next step is to look at the bearing bore. The last step is a
proper filling up of the gear inspection checklist. As given here.
Gear Inspection Checklist
The following is the checklist that is a must when carrying out an
inspection of the gears.
| Item |
Yes |
No |
| Normal wear |
|
|
| White Layer Flaking |
|
|
| Abrasive Wear |
|
|
| Spalling |
|
|
| Rippling / Lipping |
|
|
| Uneven Contact |
|
|
| Pitting / Spalling |
|
|
| Foreign Object Damage |
|
|
| Nicks |
|
|
| Destructive |
|
|
| Cracks |
|
|
| Chipping |
|
|
| Scoring |
|
|
| Corrosion/Corrosive Pitting |
|
|
| Case Crushing |
|
|
| Frosting |
|
|
| Pitting |
|
|
Utility of Gear Inspection Process
A Gear inspection process commences with the routine tasks done on the shop
floor and can even extend to manufacturing laboratory for carrying out a
complex and analytical gear evaluation. All or some of these methods are
necessary for maintaining a perfect process control and for production of
parts of the required quality. Inspection in particular, can help in
controlling the following:
- Size of gear
- Quality of gear
- Fixture mounting on machine
- Machine set-up
- Quality of the part blank
- Precision of the cutting tool
- Mounting of cutting tool
- Proper sharpening of the cutting tool
- Heat treatment process
- Condition of the equipment needed for production
Gear Checking Machine
A vital aids in the gear inspection process is the gear checking machines.
They play a crucial role in any gear inspection operation. A gear checking
machine among others is supposed to check the following things:
- Runout
- Pitch Variation
- Accumulated Pitch Variation
- Profile/Involute
- Lead
- Slope error
- Tooth thickness
