Structural Analysis of a Rotary Combustion Engine Rotor

The purpose of this paper is to describe the methodology used at John Deere Tech. Int'l to perform detailed analyses of Wankel engine rotors. Only limited numerical results are shown since these would vary with engine designs and applications. The finite element method is used to compute temperature distribution in the rotor and also compute pressure, acceleration and thermal stress due to the imposed loads. The results of this analysis can be used to identify structural inadequacies, reduce weight, or determine growth potential.

An experimental check of the validity of the FEM results was made. Correspondence between strain gage results and the computed FEM pressure stress is discussed. The varying stress level during engine rotation at critical elements in the rotor is ‘discussed in detail. Specialized finite element techniques such as submodeling are used to obtain the desired light weight rotor design while preserving structural adequacy.