AN EXPERIMENTAL STUDY OF FRICTION IN ELASTOHYDRODYNAMIC LUBRICATION,
Abstract
Measurements of friction torque have been made on a disk machine by introducing a torque sensor into the drive to one of the disks. Experimental readings of torque have been made for loads up to approximately 40,000 psi maximum Hertzian contact pressure, for rolling speeds from 15.7 to 314 inches per second and for sliding speeds up to 130 inches per second. A comparison has been made between two oils of dissimilar characteristics. The friction torques developed with an oil of high pressureviscosity exponent and low viscosity index form a strong contrast with the torques developed by an oil of relatively low pressure-viscosity exponent and high viscosity index. The difference is most marked at high loads and low sliding speeds - the pressure sensitive oil developing much larger coefficients of friction. The dependence of friction upon load and sliding speed is in accordance with recent theories of elastohydrodynamic lubrication. It has been confirmed that the effective viscosity within the contact is dependent on the rolling speed of the disks. Data is presented showing the variation of the pressure-viscosity exponent with rolling speed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 28, 1964
- Accession Number
- AD0610134
Entities
People
- M. D. Longfield