5. Thrust and leaf bearings

The leaf bearing concept emerged in the mid-1960s to overcome the operating limitations of rigid bearings. As already mentioned, rigid air bearings have limited load capacity and, above all, low damping. Low- and medium-power rotating machines operate at very high speeds and require bearings capable of ensuring stable operation (without self-sustained vibrations) and withstanding unbalance forces often greater than the static load [21] .

The leaf bearing tends to meet these needs. It consists of adding an elastic and dissipative structure between the bearing sleeve and the shaft (figure 31 ).