Bearings
Radial and axial forces act on the shaft during operation of the gas turbine. Bearings are used to transfer the forces from the shaft to the housing. The gas turbine has thrust bearings and a thrust bearing. The thrust bearings are designed to transmit the force in the axial direction, and the thrust bearing is necessary to prevent the shaft from moving in the axial direction.
The bearing is supplied with oil as a lubricant.
The plain bearing housing consists of two halves – upper and lower. Inside the housing there are shells mounted, which rest on the pads. The channel formed by half of the shells is fed with oil. As it rotates, the rotor entrains the oil behind it. Thus, an «oil wedge» is utilized – a film whose rotation rotates the shaft. To prevent displacement, the bottom liner is rigidly fastened. The halves of the body are rigidly fastened together by studs.
The thickness of the oil film in which the shaft rotates is about 0.5-0.7 mm. During rotation, the oil temperature is indicated. To reduce friction, babbitt is poured on the surface of the liners. Babbitt consists of copper, antimony and tin. In order to reduce bearing wear during start-up of the Gas Turbine Unit, a so-called rotor hydraulic elevator is used.