Abstract:
The pressure- viscosity (P- V) coefficient and solidification pressure values of lubrication oils are key testing date for the application of elasto-hydrodynamic theory to tribological design. The P-V coefficients of 20 Chinese lubrication oils were tested using the falling cylinder viscosimeter, and the lowest solidification pressure values of 16 lubrication oils among them were also obtained in this paper. The authors also made an analytical comparison between the different lubrication oils' P-V coefficients and solidification pressure, these oils are: the base lubrication oils produced by three oil fields, the synthetic lubrication oils with different chemical structure and industrial lubrication oils having many uses. The results shown as follows:
a. In order of Chinese lubrication oils' P-V coefficient value is the Shengli oil field's>Kelamayi oil field's > Daqing oil field's; whereas the order of the lowest solidification pressure of them is Kelamayi oil field's>Daqing oil fields's>Shengli oil field's. The P-V coefficients of base lubrication oils with different brand from the same oil field are quite similar, the difference between the lowest solidification pressure is not remarkable.
b. Either diesel engine lubrication oil series or gasoline engine lubrication oil series the P-V coefficient variation is not obvious; The P-V coefficients of gear lubricant and ordinary mechanical lubrication oils are different. In the same series the industrial lubrication oils with different brand have the similar lowest solidification pressure.
c. In order of P-V coefficient value of synthetic or natural lubrication oils with different chemical structure is naphthenic hydrocarbon's > paraffinic hydrocarbon's > castor lubricant's > aromatic hydrocarbon's.