Purpose
Method for testing the efficiency of additives in lubricating oils with regard to friction coefficient and wear.
Brief description of the method
With this friction-testing machine, a tightly fixed test cylinder is pressed by means of a lever system on a rotating ring wheel, which is immersed to its lower third in the test fluid. The driving motor and the ring wheel rotate together at the same speed. With regard to the number of revolutions per minute, it has to be insured that the fluid flowing into the contact point (friction wear point) between test cylinder and test ring is always sufficient. After testing, abrasive areas (elliptic wear scars) appear on the test cylinder. The dimensions of these wear scars depend on the load-carrying capacity of the test fluid. The sharply limited abrasive area allows a precise measurement, which favours the exact determination of the load-carrying capacity of the test fluid. The higher the load carrying capacity the smaller the wear scar is after a certain running time or precise distance (e.g. 100 m of the peripheral distance of the ring wheel).