Basic Mechanisms of Diesel Lubrication Correlation of Bench and Engine Tests
Abstract
The lubrication behaviour of a cylinder liner/piston ring contact in a diesel engine has been simulated in a point contact reciprocating rig. When lubricants containing ZDDP additives are used, electrical contact resistance measurements establish that a thick 'reaction film' quickly forms in the rubbed region, protecting the metal surfaces. Electrical capacitance measurements show that the film thickness can vary from 0.1 to 1 micrometer: the film appears to be a solid organic polymer with a shear strength of 50-100 MPa. Using segments of diesel engine cylinder liners from various manufacturers in the reciprocating rig, the changes in surface roughness during the running-in process were monitored. The induction time needed for the formation of the reaction film as well as the coherence of the film was studied as a function of load and temperature (in the range 150 - 250 C). A theoretical analysis of flash temperatures in reciprocating contacts confirms that these are small under the conditions in this rig, so that the measured temperatures are those actually responsible for the reactions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 25, 1991
- Accession Number
- ADA237685
Entities
People
- A. Cameron
- A. F. Alliston-greiner
- D. Cameron
- J. A. Greenwood
Organizations
- University of Cambridge