Effects of Grease Characteristics on Sound and Vibration of a Linear-Guideway Type Recirculating Ball Bearing

This paper deals with the effects of grease characteristics on sound and vibration of a linear-guideway type ball bearing. First, sound, vibration, and temperature of a linear-guideway type ball bearing were measured by changing 16 types of greases. Next, in order to explain the effects of grease characteristics (absolute viscosity η₀ of the base oil in the grease at atmospheric pressure, pressure–viscosity coefficient ξ of the base oil, and penetration P of grease) and linear velocity V on the sound pressure p and vibratory acceleration a of the linear bearing, dimensional analyses were carried out. The dimensional analyses derived dimensionless products Pp/(η₀V) and η₀ξV/P for the sound, and dimensionless products Pa/V² and η₀ξV/P for the vibration. The plot of the measured data using dimensionless products showed that both sound pressure p and vibratory acceleration a (under a certain linear velocity) decreased as the absolute viscosity η₀ of the base oil in the grease at atmospheric pressure or the pressure–viscosity coefficient ξ increased. Whereas the sound pressure p decreased as the penetration P decreased, the vibratory acceleration a decreased as P increased.