Use of semiliquid greases in closed gearboxes

Abstract

1. Semiliquid greases have a number of advantages over liquid transmission oils. The use of the semiliquid greases eliminates the need for complex seals, gives a considerable reduction in lubricant consumption, and simplifies the maintenance of the mechanisms lubricated. Moreover, the semiliquid greases are better in preventing corrosion and are effective in reducing the levels of noise, vibration, and shock loading; they are better in lubricity, particularly during startup and shutdown. The disadvantage of these products, in comparison with liquid lube oils, is that they are not as effective in removing heat. 2. The present [USSR] product line of semiliquid greases is limited. Hence the matter of developing domestic semiliquid greases for enclosed gearboxes is very urgent. 3. In the development or selection of formulas for semiliquid transmission greases, the following considerations may be used as rough guidelines. a) For multifunctional semiliquid greases, petroleum oils are the logical choice as the dispersion medium, in view of their relatively good availability. b) The most promising materials should be considered to be greases thickened with lithium soaps of 12-hydroxystearic acid; these greases are high in mechanical stability. Also very promising are greases thickened with complex calcium and aluminum soaps. c) The properties of greases can be improved markedly by the use of antioxidant, anticorrosion, antiscoring, adhesion, and other additives.