Analytical solution of the use of oblique arms in reducing the forces imposed on brackets of the vertical generator and its foundation

In large hydroelectric power-plants with a power of more than 100 megawatts, vertical generators are used, in which the diameter and the weight of their stator exceeding 8 meters and several hundred tons, respectively. In this structure, which is the location of the magnetic plates and the stator core, there are two rings with radial or oblique arms for mounting bearings of rotating parts of the generator (they are called upper and lower brackets). These arms transfer the forces due to the increase in the length of the ring (due to the increase in temperature), the radial forces applied from the turbine, and the torsion hydraulic torque from the turbine axis to the stator or its foundations. Therefore, accurate prediction of these forces and torque in the design of the structure and the calculation of compressive and bending stresses on the structure or foundation of the arms is of particular importance. In this paper, the effect of using oblique arms on the reduction of compressive stresses and the foundation forces of large vertical generators, is analyzed analytically. The effect of angle, length, number, and arrangement of oblique arm on stress and forces for three different load cases are investigated.