The pros and cons of floating bearings and ball bearings in the turbocharger

I believe that most people mention the structure of the turbocharger, the first reaction will be a turbine or compressor, turbine and the compressor is the manufacturers' technical core and would think. We also seem to have missed a inconspicuous parts good, is the turbine shaft. Shoulder maximum speed of more than 150,000 revolutions have deep processing, superb mold processing standards, resistant ultrahigh mild wear material selection, the entire selection of manufacturing process so demanding requirements turbine shaft is each turbo pressure is the most central part of the manufacturers. Play supporting the turbine shaft turbine bearings, is the protagonist of this article.
The turbocharger bearing structure related to the problems of the turbo operating reliability and durability. Turbocharger bearings are mainly divided into two categories, one for the floating bearing (commonly known as the wave Division bearings), and the other is on ball bearings. Most modern automotive turbocharger bearings using floating bearings without his durable Value ear. Floating bearing is actually set in the ring of the shaft between the ring and the shaft and ring and bearing has a gap to form a two-layer film. Ring floating in between the shaft and the bearing. Usually inner gap of 0.05mm, the outer gap is about 0.1 mm. The bearing wall thickness of about 3.0-4.5mm, manufactured by tin-lead bronze alloy, the bearing surface of plating layer having a thickness of about 0.005-0.008mm, pewter or metallic indium. The turbocharger work, the bearing between the shaft and the bearing rotation. Therefore, we can see that the shortcomings of the floating bearing: turboshaft high turn running resistance, oil pressure and high quality requirements of the the unstable dynamic control of the turbine shaft.Emphasis on the durability of the German turbine manufacturer KKK products are basically floating bearing the main picture shows the very popular K04 turbo kit
The ball bearing is more visible performance models, as the name suggests, the ball bearing is installed in the turbine shaft ball, replace the oil floating bearing position. The ball bearing advantage just floating bearing opposites: friction smaller, lower turbo lag effect is more favorable to the power limits of press; can effectively control the dynamics of the turbine shaft; lubricating oil pressure, and quality can be slightly lower indirectly enhance the life of the turbine. Its disadvantages are also obvious, is the life expectancy is less than the floating bearing, generally 70000-80000 km to the life of the limit, and maintenance costs are expensive, difficult to repair. However, due to the ball bearing very tempting to upgrade power ball bearing is still the mainstream equipment performance models.