The shear stability of the grease refers to the ability of the grease to resist the change of consistency under mechanical shear force under certain conditions, and is an important index to evaluate the mechanical stability and service life of the grease. Shear stability is related to the strength of the fiber structure of the grease and the adsorption force between the fibers. The degree of change in the structure of the grease after the shear force is expressed by the consistency of the grease, that is, the structure of the grease is subjected to mechanical shear The change value of the penetration before and after the force. The change in the working penetration of the grease after the extended shear test can be considered as the shear stability measured under the test conditions. For the test method, see GB/T269 "Test Method for Shear Stability of Grease", which is equivalent to ISO2137-1983.

    Analytical equipment and materials: cone penetration tester and full-size grease working device in accordance with GB/T269 regulations; grease shear tester shown in the figure on the right; constant temperature water bath that can be maintained at 25℃+-0.5℃; Thermometer calibrated at 25°C; stopwatch, etc.

    Test procedure: Keep the temperature at 15~30℃r into the grease cup of the working machine, no need to further control the temperature of the working machine of the grease; assemble the working machine and install the working machine on the shear testing machine, try The sample is reciprocated up and down at a rate of 60 times per minute on the shear test machine according to the prescribed or agreed times; immediately after the work on the sample is completed, the grease working device is placed in a constant temperature water bath of 25℃+-0.5℃1.5H ; Then take out the working device and reciprocate 60 times within about 1min; then determine the cone penetration value of the grease according to the test method conditions, and use the 60 working cone penetration value before the shear test and after the shear test (10,000 60 times of work or after 100,000 times of work) The difference in cone penetration indicates the shear stability of the grease. The smaller the difference in cone penetration, the better the shear stability of the grease.