FAG FE 8 - Bearing test / DIN 51819
Intended to determine the wear resistance and coefficient of friction of a lubricant under mixed / limited lubrication conditions. On two test benches, two pairs of bearings are run under different conditions (load, temperature, time), then the wear of the rolling element of the cage is measured.
FAG FE 9 - Bearing test / DIN51821
Intended to determine the life of a fat and its performance limit for operation at high temperatures (up to 250ºC). The test is carried out with five pairs of angular contact ball bearings which rotate at variable speeds (3000, 6000 rpm) under axial load (1500, 3000, 6000 N) and a high temperature until the failure of the tested fat. In the same way, and in accordance with DIN 51825, the temperature at which the product is able to reach the 100h defined by this test defines the upper limit of these fats. In the same way, and in accordance with DIN 51825, the temperature under which the product is able to exceed the 100h defined for the F50 value of this test is established as the upper limit of type K greases.
Test to determine the useful life of a grease This test determines the life and maximum performance at high temperature of a grease. It consists in fixing on a test bench five independent equipments, each with two bearings mounted on an axis, making it possible to test several greases. At a pre-defined temperature and speed (up to 230 ºC and between 5000 - 25000 rpm), the bearings are made to work simultaneously, applying an axial (100-1100 N / roll) and radial (50 - 900 N / roll) load. .) until the failure. These elements make it possible to establish the service life of the lubricating product and to calculate the lubrication frequencies.
Consistency of a fat (NLGI)
According to the standard, its stability against the mechanical shear of thickening soap. According to DIN ISO 2137, the consistency is determined by the depth, measured with an accuracy of 0.1 mm, to which a standard cone sinks into the grease under given conditions. The results are the basis of the NLGI grade established by DIN 51818. This result represents the hardness or flexibility of the grease.
Drop point of a fat
The drop point is the temperature at which the three-dimensional structure of the grease begins to flow to the test vessel. This value is measured according to the requirements of DIN ISO 2176
Determination of oil separation
The oil contained in the greases tends to separate from the latter during storage. This separation does not represent, a priori, a deterioration of the fat, because it can be mixed again with the appropriate means. According to DIN 51817, after exposure for 7 days at a temperature of 40ºC of a test container filled with fat and weighing 100g, the quantity of oil released is measured and the percentage of oil is indicated. weight loss that this represents.