Internal gear is a gear using its teeth cut in the internal surface area of a cylinder and meshes with spur gears.

In its manufacturing, due to its shape, the most common hobbing machine found in spur gear production can’t be used. Generally it is made out of gear shaper (or gear shaping machine) equipped with a pinion cutter. More recently, the efficiency of internal gear cutting offers been improved by a different procedure called skiving.

Due to the thinness of the ring, it really is sometimes difficult to produce high precision. However, gear grinding to boost precision grade is limited by the number of producers and their obtainable grinding facilities resulting in very high cost.

Also, although it is normally too expensive to make helical teeth internal gears, Ever-Power has managed to get possible to produce them simply by adopting equipment that can cut them simply by making pinion cutters rather than needing helical guides.

Normally, internal gears can be used with the same module spur gears, depending on the amount of teeth combinations, nonetheless it is necessary to note the possibilities to getting involute, trochoid or trimming interferences. For using Ever-Power standard share gears, please consult the PDF formatted “Specialized Details of Internal Gears” section for usable quantity of teeth combinations.

Internal gears tend to be found in applications involving planetary gear drives and gear couplings. There are three main types of planetary gear mechanisms: planetary, solar and superstar types. Based on the type and the design of which shafts act as input and result, many variations of velocity tranny ratios and rotational directions are produced.