An Internal Gear may be described as the opposite of an external gear in that the teeth point towards instead of away from the center, and addendum and dedendum consider reverse positions. Internal Gears provide a compact parallel shaft tranny drive with large velocity reduction. Used with a standard spur pinion the ratio is the same as that of two exterior gears, but the center distance is much smaller. Where it’s important to have two parallel shafts rotate in the same path, the inner gear eliminates the usage of an idler gear.

Internal Gears possess many advantages when properly applied. One such benefit is reduced sliding actions. The corresponding working surfaces of the teeth of an internal gear and pinion are more nearly of the same size than is the case with an exterior gear and pinion having the same tooth ratio and tooth duration. Which means relative slippage of one’s teeth is less regarding the internal. This point presents one of the benefits of using Internal Gears. The sliding actions of 1 tooth over another causes friction; and as friction results in tooth put on, a reduction in the quantity of sliding action is usually desirable.

Internal Gear drives could be operated with the gear in a set position and the pinion rotating along the pitch line, or the apparatus may be free to rotate with the pinion rotating in a fixed position.

When planetary gearbox mating pinions are too close in size to the apparatus, interference may result. Consequently, the difference in teeth of the pinion to the gear should not be significantly less than 15.

RUSH GEARS inc. offers standard Internal Gears in STEEL, STAINLESS STEEL, CAST IRON, BRONZE, Aluminium, DELRIN and NON-METALLIC (PHENOLIC). We will gladly produce made to order Internal Gears to meet your needs.