Evaluation of oil-film thickness along the path of contact in a gear mesh by capacitance measurement

Abstract

This paper presents a new method to evaluate the oil-film thickness in gears. By using high speed capacitance measurements in combination with an exact timing it is possible to detect the changes in capacitance along the path of contact. With knowledge of the contact area, the oil-film thickness can be calculated from the capacitance measurements. The design of the test rig relies on a good electrical insulation and accurate speed measurements. First test results show that the changing conditions in the contact can be detected by the measurement of the capacitance.