Technical Paper
Development of Noise Reducing Grease
2011-04-12
2011-01-1246
In recent years, background noise in vehicle interiors has tended to decrease more and more in hybrid and luxury cars. As a result, there is an increased demand for noise reduction capabilities of automotive grease, in addition to the original lubrication function. In this study, we report the mechanism of noise reduction in car air conditioners, and describe a new grease that meets both excellent noise reduction and low temperature performance. In the collision model, sound pressure is generated by collision velocity and material properties (ex. Poisson ratio, Young's modulus). When the grease is applied over the area around the collision point, collision velocity is reduced because of the viscous resistance of the grease. Therefore, it is effective to use highly viscous base oil for noise reduction. However, the base oil also harmfully influences low temperature performance.