Computer#aided design of the pump profile with epicycloidal gearing using MathCad tools

The article discusses a method for determining the relative eccentricity χ, used in calculating the thermal balance of an internal combustion engine sliding bearing. When performing this calculation, a number of temperature values are set in the bearing oil layer. For each set temperature, the engine oil viscosity value μ and the bearing load factor Ф are determined. To determine the relative eccentricity, graphical dependencies of the load factor on the relative eccentricity are used as input data. The thermal calculation of the sliding bearing showed that the accuracy of determining the relative eccentricity χ is of great importance. Their inaccurate definition leads to a failure of the thermal balance in the bearing. In addition, the method of determining the value of χ by the accepted value of the ratio of the working length of the bearing to the diameter of the connecting rod neck of the crankshaft (graphically) for this calculation is quite time-consuming. For this reason, the graphical method for determining χ has been replaced with an analytical one. Relative eccentricities were obtained using the least squares method. An algorithm has been developed for automated construction of transverse and longitudinal profiles of an oil pump with epicycloidal engagement.