1.
Development of lubrication theory integrating science, technology and
engineering application
In the late 1970s, Prof. Dowson
coupled the Reynolds hydrodynamic lubrication theory with the Hertz
elastic contact theory, and proposed the elasto-hydrodynamic
lubrication (EHL) theory for the purpose of lubrication design of point
and line contact involved in engineering fields, such as gears and
rolling bearings. However, since the calculation model of the theory
neglected many practical engineering factors, it was greatly restricted
in engineering applications.
In the early 1980s, we proposed the research
objective to develop an engineering model of the EHL theory. We
gradually extended the EHL theory by considering various practical
engineering factors, including thermal effects, non-newton
lubricant, unsteady working conditions and
surface roughness. Furthermore, we built a set of most universal
lubrication equations and improved the corresponding numerical analysis
technique, which finally established the engineering model of the EHL
theory taking account of the combination effect of various engineering
factors. Meanwhile, we developed a measuring technology to investigate
the property of the EHL film at micro-scale. All the researches have
been applied in the lubrication design of railway bearings, satellite
bearings and worm gear to enhance the load capacity significantly.
2. Promotion the development of tribology discipline with times
In the early 1990s, based on our researches on
the EHL theory, we noticed that the current viewpoint of lubrication
states was discontinuous. So we proposed and devoted ourselves into the
research of nano-scale thin film lubrication,
which was latterly regarded it as an unknown
lubrication state between boundary lubrication and elasto-hydrodynamic
Lubrication.
For the thin film lubrication, we developed an interference light intensity technology to measure
the nano-scale film thickness of lubricant,
which can achieve a resolution of 1 nm and the measurable minimum film
thickness was about 3 to 5 nm. Through a series of systemic
experiments, we investigated the formation mechanism and
characteristics of the nano-scale thin film;
then we established the physics model of thin film lubricant and
described the state transformation relationship of lubrication. Some
previously unknown phenomena such as surface effect and time effect
were firstly revealed.
Our researches on thin film lubrication
promoted the latter development of nano-tribology
in SKLT, including many important progresses in rheology
property of confined liquids, in micro-fluids flow, in ultra-precision
polishing technology, etc. The developments in nano-tribology
promoted a close combination between conventional tribology
theory and surface physics and chemistry, which revealed to us the
importance role of surface/interface effect on nano-scale.
Our researches were also promoted significantly by application of
modern micro experimental techniques and analysis methods based on
molecular theory.
3.
Standing on the front edge of tribology
discipline and encouraging the growth of young scholars
In the past 30 years, with the consistent
support from National Natural Science Foundation of China, our research
activities spanned three historical periods.
In the 80s, we researched macro-scale tribology focusing on EHL;
In the 90s, we focused on thin film lubrication
to promote nano-tribology research;
From the new century, we expanded our research
fields to include the surface and interface technology
During the past 30 years, our research group has graduated more than 50
master and Ph.D students, and cooperated with
about 20 postdoctoral fellows. Nowadays, most of them have become
outstanding and active scholars, forming a booming force in the fields
of science and technology. By now, two of them were selected as Cheung
Kong Scholar Chair Professor, four of them won the National Science
Fund for Distinguished Young Scholars, two of them got the awards of
the National Excellent Doctoral Dissertation.The
way before us is much challenging but also full of chance, we need to
surpass the past achievements, and work harder for a brighter future!
