Influence of geometric error and surface morphology of roller and mold on vibration performance of mold

There are two types of excitation on the rotor of rotating machinery, one is the excitation force acting on the rotor directly, the other is the motion of the foundation. Among the exciting forces acting directly on the rotor, the most common one is the unbalanced centrifugal force. In addition, there are electromagnetic excitation of rotor in motor and fluid excitation of rotor in turbomachinery.

In fact, the shape error and surface topography of two relatively moving contact surfaces will also cause vibration of the system. Due to the influence of processing accuracy and other factors, there is a certain shape error (roundness error) in the outer circle of the mold and roller, and the surface of the mold and roller is not completely smooth, but has a certain surface roughness. Both surface shape error and surface roughness can affect the vibration of the mold to a certain extent.

Based on the vibration model of centrifugal casting machine, considering the surface shape error and surface roughness of roller and mold, the calculation model of excitation caused by surface shape error and surface roughness of roller and mold was established. Combined with the vibration model, the transfer matrix method was used to construct the mold vibration performance meter which can consider the geometric error and surface roughness of roller and mold Finally, the influence of geometric errors between roller and mold surface on the vibration performance of mold rotor is discussed through an example.