Internal Gears

Internal gears can be recognized by their cylindrical pith surface with teeth, which are engraved from inside of the rim instead of outside, and are parallel to the axis. These gears are used in combination with a pinion. The teeth of the internal gears are such designed so that they can conveniently bear
heavy loads and the weight of these loads get evenly distributed among them.
The primary function of the internal gears is to transfer the rotatory
motion between parallel shafts that rotate in the same direction. Here,
again the teeth of the internal gears play a vital role. The non-binding
design of these teeth confirms silent and unimpeded operation.
A low-sliding and high-stress loading can be performed through the internal
gears. This quality also makes these gears unique. Internal gears are quite
economical and also support adverse working circumstances. Internal gears
are used most with the planetary gears as they offer large reduction ratios
when used with them. The metal from which these gears are manufactured is
brass, and it's the only metal for the purpose.
Application of Internal Gears
Internal gears are one of the highly used and efficient variety of gears.
They are often used for applications like rolling, indexing, timing, and so.
They also function as a tool for the purpose of creating solid models of
drive components. Internal gears commonly found their application in
industries like sugar mills, cement plants, fertilizers and pesticides,
power generation (especially thermal), steel, textile, mining, material
handling, machine tools, to name a few.

Diagram showing a complex network of internal gears along with some other
gears in an engine
Advantages of Internal Gears
- These internal gears result in minimal sliding action.
- They are of one of the cost-effective varieties of gears.
- Internal gear drives may be operated even when the gear is static.
- The formation of these gears precludes interference in the internal
meshes.
- The teeth of internal gears are relatively less slippery due to their
unique formation.
- These gears are considered ideal for working efficiently even in
extreme conditions.
- The special non-binding tooth design of these gears ensures smooth
and quiet operation.