A method for calculation of oil supply to the parts of units of agricultural machinery

Force lubrication systems are widely used in engines and transmission units of agricultural machinery; the oil in them is supplied to consumers by the action of oil pumps, thus reducing the nonproductive friction losses and providing the necessary thermal conditions for parts. For calculation of lubrication systems when carrying out the design and further development works, mathematical models are used, representing the complex systems consisting of large number of nonlinear equations. Such systems require the development of special solution methods. A solution method of system of linear and nonlinear equations describing the oil movement through the channels of force lubrication systems should provide the simplicity, unambiguity and high accuracy of calculations. The analysis of mutual influence of the calculated quantities is performed. The three main dependencies are pointed out: the coefficient of friction losses for each of the supply line sections is a function of the volumetric flow rate of oil; the oil density is a function of the pressure in input-output section of the supply line; the pressure by the action of centrifugal forces is a function of the oil density at the input of rotating section. Based on the performed analysis, a solution method for mathematical model of force lubrication system satisfying the suggested requirements is developed. To validate the method, the system of planetary transmission lubrication is calculated; the total volumetric flow rate of oil in the process of its operation under various modes is measured. The obtained results show the good match of calculated and measured values of the volumetric flow rate of oil, which confirms the accuracy of the proposed solution method for system of equations and the possibility of its use for calculation of lubrication systems.

transmission, engine, force lubrication system, calculation, method, mathematical model