Tooth Fillet Stresses of Gear with Thin Rim : 5th report, Tooth Fillet and Root Stresses of Internal Spur Gear Supported by Pinned Coupling

A method to apply the approximation formulae(1) for tooth fillet and root stresses of a thin-rimmed gear to the calculation of stress state of an internal spur gear was developed(3). In the case of an internal spur gear which is supported by pinned coupling similar to geared coupling, the tooth fillet and root stresses calculated by this method have shown fairly good agreement with the measured values and the validity of this calculation method has been substantiated. The influences of the supporting conditions, dimensions of the internal spur gear and of the number of planet pinions on the tooth fillet and root stresses have been investigated. It has been clarified from the standpoint of stresses induced in an internal gear that the flexible and distributed supporting of an internal gear such as by pinned coupling and/or geared coupling is better than clamping of an internal gear at some fixed points, e.g., by bolts.