Study on Dependency of Dynamic Properties in a Rolling Roller on Fine Coal Upon the Running Velocity

In previous study, the relation between dynamic behavior of the system and powder characteristic during rolling the roller on the fine coal spread over a table were investigated with the experimental equipment which consist of an elastic support roller system. In this study, we decreased rigidity of supporting part of experimental equipment to decrease natural frequency. These changes of structure enable us to specify a vibration during rolling the roller. We investigated rotating speed variation which is caused by roller slipping and horizontal vibration acceleration. In addition, we investigated relation between these experimental data and travel speed of the experimental equipment. As a result, both rotating speed variation and horizontal vibration acceleration increased with increasing of travel speed of the experimental equipment. After taking maximum value, both rotating speed variation and horizontal vibration acceleration decreased. To clear up the causes of the phenomenon, we investigated dependency of apparent friction coefficient upon slip ratio. However, noticeable dependency wasn’t represented. In addition, we calculated both horizontal vibration acceleration and RMS with frequency band limiting which is same range as natural frequency of the experimental equipment. As a result, it is found that natural frequency of the low level is excited as a main component and the excited frequency component changed to high level with increasing of travel speed of the experimental equipment.