Total Productive Maintenance (TPM) - New way of protecting against mechanical wear
Wear in engines, gearboxes, and other mechanical equipment is caused by friction between metal surfaces. Lubricants create a protective
film in order to prevent the metal surfaces from coming into contact. Taking a new approach, Total Productive Maintenance modifies the
structure of the surfaces; making the metal smoother and providing long-term protection against wear.
Conventional lubricants are used to create a film between metal surfaces in order to prevent metal-to-metal contact. In addition, lubricants
also conduct heat generated by friction away from the area of contact. In an ideal situation the metal parts would slide on a ‘pillow’ of
lubricant and there would be no direct contact. In practice, no lubricant can totally prevent contact, especially in extreme conditions. When an
engine is started in cold weather, for instance, the valve mechanism has to work for a short period of time without any lubrication at all.
Problems can also be caused by many other factors: water, dirt, or other contaminants may enter the lubrication system, different parts may
rotate at different speeds, or there can be significant variations in external conditions.
An expensive option
Various materials are added to oil during the lubricant manufacturing process to improve its properties, and these additives account for the
differences between lubricants. The additives are intended to slow down the wear process or prevent oxidation, corrosion, and freezing.
They may constitute as much as 75% of the lubricant price. Additives are also used to promote a stronger oil film, which can be achieved by
adding materials that consists of long molecule chains.
Other types of additives can be used to smooth and strengthen the metal surfaces, and there is evidence that these methods can slow the
wear process and decrease friction. The best results are achieved when the mechanical part to be treated are still in good condition. The
effect is, however, not long-lasting and such treatment can be expensive over the long term. In almost all cases, new additive has to be
applied each time the oil is changed.
Building a new, smoother surface
Total Productive Maintenance is not based on the conventional idea of creating an oil film between the contact surfaces. Instead, it modifies
surface structure of the metal, forming a new, very smooth metal-ceramic surface. The active constituents of the Total Productive
Maintenance compound consists of a mixture of natural minerals based on magnesium silicate and catalysts. Treatment simply involves
adding the compound to the original lubricant and operating the equipment for a period of time under certain conditions. The lubricant
carries the Total Productive Maintenance compound to the friction zone, where it gradually starts to react.
The reaction at the heart of the Total Productive Maintenance process involves an exchange of atoms. The magnesium contained in the
Total Productive Maintenance compound yields its place to ferric atoms from the metal surface, and the silicate groups are incorporated
into them. New, larger-volume Ferro silicate crystals are formed. The friction between the metal surfaces produces the heat energy required
for the reaction. The micro relief of the surfaces consists of peaks and valleys, and heat is generated as the peaks are broken off by contact
between the surfaces.
The ferro silicate crystals fill the microscopic holes and crack in the metal surfaces, and protrude above the original surface. The parts
being treated actually increase in mass – a chance that can be detected using precision measuring equipment. The reaction ends
automatically when the two metal surfaces no longer make contact and there are no more free ferric atoms.
Low friction coefficient
This results in a situation where two metal-ceramic surfaces are in contact. These surfaces have very low friction coefficient, even in dry
conditions. The clearances are decreased, the operation of the machine is smoother, and there is a lot less stress on the components.
Furthermore, there is no longer a critical need for lubricant to keep two coarse metal surfaces apart. There is less vibration, less friction,
less heat, and less oil contamination. Depending on the type of equipment, Total Productive Maintenance can reduce fuel or energy
consumption by 3-30%, reduce emissions by 10-40%, decrease spare part expenses, reduce repair costs, reduce the need for
maintenance stops – increasing capacity utilization and reliability and equipment operating lifetime.
Total Productive Maintenance products are unique in their ability to compensate for wear and provide effective protection for metal friction
surfaces over extended periods of time. It must be remembered that in case of new or almost new equipment the improvement may not be
measurable, but in practically every case the ferro silicate structure forms to protect the original friction surface.
Wide range of applications
Total Productive Maintenance can be used in all equipment that contains friction and sliding surfaces made of FE-based metal, regardless
of whether they are new or worn. It has been tried and tested in a range of applications including electric motors, internal combustion
engines, transmissions including differentials and chains, compressors, bearings, hydraulic equipment, pumps, and blowers.
An important advantage of the Total Productive Maintenance is that it can be used to treat bearings and contact surfaces without
disassembling the machines. This kind of Total Productive Maintenance increases operational reliability, reduces scheduled and
unscheduled downtime and helps control production costs.
This article has focused on practical application of Total Productive Maintenance. However, in wider context Total Productive Maintenance is
a whole maintenance program concept. Jack Roberts, Ph.D., Department of Industrial and Engineering Technology, Texas A&M
University-Commerce explains, learn more....
More Information
'An Introduction To Total Productive Maintenance' by Venkatesh J., and published by The Plant Maintenance Resource Center concludes:
"Today, with competition in industry at an all time high, TPM may be the only thing that stands between success and total failure for some
companies. It has been proven to be a program that works. It can be adapted to work not only in industrial plants, but in construction,
building maintenance, transportation, and in a variety of other situations." Learn more....
RVS® Technology is a family of products offering Total Productive Maintenance functionality for variety of industrial applications from
transportation to plant machinery, learn more....
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