Lubrication of Non-Reactive Surfaces at High Loads

By non-reactive is meant that the  surface will not react with  what  are  customarily  known  as EP elements such as  chlorine, phosphorus, or sulfur compounds. While there is little likelihood of extensive use of  some metal  combinations, it is well  to mention the possibilities. Thus,Antler suggests that 0.03 to 10  per  cent of trimeric  tin  sulfide compounds in  either  oils  or lubricating greases will  increase  the anti wear  qualities of the lubricant on surfaces such as  titanium-on-titanium, stainless steel-on-stainless steel, or gold-on-gold. The same  additives are also  said to be  effective on plastics, such as “nylon”, polyvinyl  chloride, polyethylene, etc.

Chromium is inert to most sulfur compounds but  will  react  with  most  chlorine compounds. Consequently, in  lubricating stainless steel  gears  under  heavy  loads, the  use  of chlorine compounds is  dictated.

Manufacturers  of gears  from  special  metals or  other  materials will no  doubt have  suggestions as to  the  proper  lubricants. Since EP agents are not  effective on  Babbitt, use of such  compounds in lubricants for  certain journal  bearings will  not  increase  the  lubricating  value.

Turbine Oils

In many turbine installations the oil must  serve  not only the bearings  but  also  the  reduction  gearing and  perhaps the  thrust  elements. Therefore, consideration of this type of lubricant is necessary. The viscosity of the oil used in geared turbines is generally a compromise since the bearings would require a lower viscosity than the gearing. The base oil should be in the range of 300 to 500 SUS at 100 degree F. This oil should be  well refined  so that  it  will  have  long  life  and  so that  any naturally  occurring  compounds which might  contribute  to  emulsions are  removed. All of these points to solvent refined oils.

Alkyl  phenols, such as 2, 6-ditertbutyl – 4 – methyl phenol, or “Ionol” in a  proportion of 0.1 to 1 per cent are  satisfactory  oxidation  inhibitors for  most  turbine  oil formulations.

Rust  inhibitors should  be  of a nature  which  will not  contribute  to  emulsions nor  be  removed  from the oil by water. Or this reason “Lubrizol 850” or “Alox 1832” can be used. The former is effective in concentrations o 0.05 to 0.10 per cent and the latter in amount up to 2.5 per cent.

An  antifoaming  agent,  such  as a dimethyl  silicon polymer, in  a  concentration of about 0.001  per cent, should  be  present  in turbine  oils.

According to Landis et al. the emulsive tendencies of antirust turbine oils can be reduced by the addition of small amounts of aryl sulfonic acids or their salts. A typical composition  consists of : a solvent  refined  oil having  a viscosity  of 350 to 600 SUS  at  100 degree F  and  containing  0.25  per cent  by  weight  of  2, 6 – ditertbutyl -4 – methylphenol; 0.1 per cent  of  phenyl  alpha  naphthylamine; 0.1 per cent  of an  antitrust  agent obtained   by  reacting  oleic  acid  with  triethylenetetramine, in a molar ratio of 1.3  to 1, to  produce an  intermediate  product  which  is  then  reacted  with  triisobutenyl  succinic  acid  anhydride in a molar  ratio of 2.3 to 1; and  0.02 per cent  of sodium  petroleum  sulfonate. As  a  substitute  for  the  last  ingredient, 0.02 per cent  of either barium  or zinc  petroleum  sulfonate  or  0.05 per cent  of  ammonium  petroleum sulfonate, can  be used. The proportion of such demulsifies is critical and an excess defeats the purpose.

Industry Trends As They Affect Transmission Lubrication

Every industry  is alert to  equipment  and  processing  changes whereby  improvements can  be  made in quality and  quantity of their  products. It is  only  by  such  changes  that  this  nation or  any  country  can continue  to  provide  what  have  come  to be  considered the  necessary  elements of  our  mode  of life. Practically any specific   industry could be singled out to indicate this trend. Everyone is familiar with the steps being taken by the steel industry in this regard, but perhaps a better illustration concerns the miracle of modern agriculture. Fewer farmers than  formerly are cultivating less land but producing an over abundance of food and fiber. The change has taken place in one generation. Thus, in 1920 the product of one  farmer  would  feed eight  persons, whereas  in 1963 one farmer  can produce   enough  food  for  twenty   eight people. Most of the above increase has occurred since 1950   during which period the output per man on a farm has doubled. One factor making this change possible is the availability and use of expensive machinery. Proper gear and transmission lubricants assure that this machinery operates satisfactorily and with a minimum of difficulty.

The lubrication industry can take pride  in the fact  that  the  lubricants  it  supplies are  a very  essential part  of the  miracle of modern agriculture  and also  of the  miracles  taking  place in other industries. As  a corollary,  it might be kept  in mind that  further  improvements  in  production and in  services which are  accepted as a part  of our  living will only be possible  if the  proper gear and  transmission lubricants are  available.