Bearing-Load Analysis and Permissible Loads as Affected by Lubrication in Aircraft Engines

FOR the rapid calculation of bearing loads in aircraft engines the authors have developed an analytical method that is described for the first time in the paper. This was derived from the long tedious graphical method that was formerly used and its accuracy is asserted to be sufficient for all purposes of engine design.

Results of an analysis of the bearing loads in the Curtiss V-1570 Conqueror engine which were obtained by the graphical method are first presented in considerable detail. The Wright R-1750 Cyclone is next analyzed, the method that was employed not being as precise as that used for the other engine. An application of the analytical method using empirical constants derived from a graphical analysis of various engines is also presented. Numerous illustrations and tables supplement the text.

Use of the pv factor as an index of carrying capacity is objected to by one discusser* who stated that this factor is only an indicator of the quantity of heat generated in the bearing. While admitting the validity of this objection, one of the authors, in replying, points out that since the pv factor does indicate to some extent how much heat is generated in a bearing, it, therefore, serves as a measure of the quantity of oil required to cool the bearing.