The choice of design parameters of main and conrod bearings for passenger car engines

Abstract

BACKGROUND: The creation of a new internal combustion engine begins with a preliminary design, during which the architectural design of the engine is born, the main features of its basic components are determined. Bearings (in this case, sliding bearings) are the cornerstones of the design, which create the foundation and form the basis – the skeleton of the power train mechanism and, as a result, the image of the future engine. Therefore, the exact selection of these key engine components is an ongoing challenge.

AIMS: Тo develop and propose an engineering method for selecting bearing parameters based on a statistical analysis of the most successful car engine designs implemented in practice.

METHODS: The method of comparative analysis of relative loads was used in the work, which allows to evaluate the loading conditions and the bearing capacity of main and conrod bearings using relative values familiar to engine engineers, such as the ratio of the diameters of the conrod and main journals to the cylinder diameter (d/D_c, d1/D_c), the ratio of the length of the journal to their diameters (L_cp/d, L_mp/d) or to the diameter of the cylinder (L_cp/D_c, L_mp/D_c), etc.

RESULTS: Simple but physically understandable values have been obtained that characterize the operating conditions of the bearing, with the help of which, using the available catalogs of manufacturers, the designer has the opportunity to select the bearing shells closest to his, the designer’s, requirements – i.e., choose the type, size of the bearings and potential supplier.

CONCLUSIONS: The proposed method for selecting the design parameters of automobile engines bearings can significantly reduce the amount of computational work at the stage of preliminary design of the power mechanism (crankshaft-cylinder block-rod-piston group). The data presented in the work can also be useful for updating the long-outdated data presented in the educational literature of the 70s–90s.

Keywords

sliding bearing / bearing shell projection area / piston area / conditional average pressure in the bearing / relative diameter / relative length of the bearing

Funding

ФГУП "НАМИ"

RIGHTS & PERMISSIONS

Zlenko M.A., Terenchenko A.S., Shibaev I.S.