The phenomenon of cavitation consists in the disruption of continuity in the liquid where there is considerable local reduction of pressure. The formation of bubbles within liquids (cavitation) begins even in the presence of positive pressures that are equal to or close to the pressure of saturated vapor of the fluid at the given temperature.
In 1935 the U.S. Army Air Corps held a “fly-off” between two aircraft vying to win the contract for the military’s next long-range bomber. The competition was regarded as a mere formality because Boeing’s Model 299 was the logical choice. It could carry five times as many bombs as the army had specified and fly faster with twice the range of previous bombers.
In their search for the latest and greatest management and technical innovations, which often arrive with glorious trappings and fanfare, organizations often overlook opportunities to correct deficiencies that are so ingrained within the organization that they are often accepted as normal. Even simple changes can profoundly affect an organization’s effectiveness and bottom line.
“My question is regarding lubricant selection for a heavily loaded, slow-speed gearbox that faces dropping viscosity and increasing wear issues. The gearbox is used in a steel melt shop and has a forced lubrication system with an operating temperature of 52 degrees C. The manufacturer’s recommendation is a 680 viscosity grade (VG) mineral oil, but should we choose a 1000 VG polyalphaolefin (PAO) oil or a 1000 VG mineral oil with plastic deformation (PD) additives?”
A chain is a series of traveling journal bearings with a means to engage the teeth of a sprocket and transmit force and motion. Because each chain joint is a bearing, proper lubrication is essential to obtain the maximum service life from a chain drive or conveyor.
