Abstract
In order to measure accurately the oil-film pressure in machine elements such as plain bearings and rolling contact parts without reducing the rigidity and changing the configuration of sliding surface, we have developed a piezo resistive-type thin-film pressure sensor. Using physical vapour deposition technique (PVD-sputtering), a sensor was deposited with a thickness of approximately 3∼5 μm on the sliding surface. The electrical resistance of such pressure sensors varies under pressure (piezoresistivity). But when used in machines such as internal combustion engines, sensors are subjected to extraneous influences causing measurement errors such as temperature change and deformation of the sliding surface. In order to reduce these errors, the material and the shape of the sensor were devised: To reduce first the temperature dependence of pressure sensitivity, alloy composition of the sensor was optimized. To reduce the temperature dependence at higher temperature caused by oxidation of sensor material, aluminium-nitride film, instead of oxide films, was applied successfully as an insulating and a protection film. Then, to reduce the error due to sensor deformation, a new sensor shape was devised, that possesses a uniform and low strain sensitivity. This has enabled to correct for error properly or even made the correction unnecessary for practical use. Using this newly-developed sensor, the distribution of oil-film pressure was measured in engine main bearing and in piston pin-boss.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call