Dynamic Characteristics of Roller Mill

In order to investigate the dynamic characteristics of UBE Loesche mill, accelerations, displacements and strains on various places of a small-sized UBE Loesche mill LM3.6 are measured in actual operation. Then analysing these varying amounts by the F F T real-time-analyzer, frequencies of the vibration of the mill are obtained. On the other hand, replacing the UBE Loesche mill by a vibration model with five degrees of freedom with respect to a vertical motion and estimating masses and spring constants of each part of the mill by means of experiments or calculations, the theoretical natural frequencies of the model are calculated. Then the theoretical results are compared with the experimental ones. Consequently, the following is clarified : The vibration of the mill in actual operation is considered to be a forced vibration because the lowest natural frequency of the mill is fairly higher than the main vibration frequencies of that in actual operation. It has been observed that rollers and table of the mill are in contact with each other, and move in the same phase in the vibration. The higher frequency components of the mill are decreased by accumulators. Furthermore, varying component of the external force applying the case of the mill seems to be about 60% of the force applying the table.