Internal Gears

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

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

Because of the thinness of the band, it is sometimes difficult to produce high precision. On the other hand, gear grinding to boost precision grade is bound by the amount of manufacturers and their available grinding facilities resulting in very high cost.

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

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

Internal gears tend to be used in applications involving planetary gear drives and gear couplings. There are three main types of planetary equipment mechanisms: planetary, solar and star types. Depending on the type and the design of which shafts become input and result, many variations of rate transmitting ratios and rotational directions are produced.