Nuclear Power plants Gear Lubrication

Present indications are that the principal gearing in nuclear power plants will be in connection with turbines. Such  reduction units should be  far  enough removed  from the area of high  radiation that no degradation  of the oil  from such  a source  will occur.

Cox et al.^14 who have considered this matter state: “Irradiation tests of turbine oils show that maximum expected radiation doses in  current and projected power plants over a twenty year period  does not change the  physical  properties of the oil. Oxidation stability and other properties are, therefore, still of most importance in turbine oil selection”.

Also  Okrent^43  in treating  design considerations of nuclear powered  surface vessels concludes that the  reduction gearing  in connection with  the  turbine presents no problems  from a radiation standpoint. In spite of the  above thoughts, Watson^51  mentions  that in  nuclear  power  generating  stations, a  number of applications  will be found where  gears  should  be run  without  lubrication. Experiments were, therefore, made with various materials, run in a dry state, with latter wear. As a  result, it is suggested that if loads are not heavy, spur gears, made of  case hardened  En steel, phosphate prior to coating  the flanks with  molybdenum  disulfide, can  be run  continuously, in a dry state, without  measurable  wear. Also  a worm wheel , made  from  woven  asbestos base  with  a case  hardened  steel worm, is promising for  operation in a dry  state.

No doubt, when and if gear oils with radiation resistance are necessary, suitable fluids will have been developed. Thus, polybenzenoid   compounds containing short alkyd groups show promise in such applications.

One  interested  in this subject might  avail himself  of a series of  eight  papers devoted to “Non-conventional  Lubricants  and Bearing  Materials such  as Are Used  in Nuclear  Engineering”. These were presented at the Manchester college of Science and Technology on April 12, 1962 by the lubrication and Wear Group of The Institute of Mechanical Engineers (British).   

Reasonable Costs of Gear and Transmission Lubricants

Cost is a quality just as are physical characteristics, and by discussing it immediately following characteristics, the reader will have in mind all of the requirements of gear oils and can thus visualize the fact that considerable effort and precise compounding goes into the manufacture of a satisfactory lubricant.

At one time gear oils consisted, in the main, of black oils which were not too well refined. While some residual products are now sold for the purpose, most gear lubricants are on par with motor oils in quality and price. As further demands are made on gear lubricants for specific applications, more expensive additives and even synthetic fluids will be required in some cases. Thus, the trend of cost of such products can be expected to increase to some extent. In return, the consumer will obtain a better product and in many cases a longer service life.

It is appropriate, when considering the cost of a lubricant, to also keep in mind the cost of the equipment to be serviced. The proper lubricant, applied as needed in the right amount, will protect and prolong the life of machinery many years.