Abstract: Tamping machine is a kind of special engineering equipment which is used for railway construction．Tamping device being used to compact ballast is the key part of tamping machine, with which two main tamping processes, clamping and vibrating, could be carried out. Clamping squeezes the stones to flow under the sleeper and vibrating compresses ballast. The development of tamping device is briefly introduced, and then the current status of tamping device and the exciting technology are discussed in detail．Combining with project practice，the problems concerning excitation technology of tamping device in high frequency and adjustable amplitude are analyzed, and the new electro-hydraulic excitation for tamping device is proposed．The novel electro-hydraulic exciter can increase the export force, realize high amplitude during certain frequency range and solve the problem of bias impact to the cylinder. Its key technology is realizing the control of excitation frequency and amplitude through the rotation valve spool which is driven by step motor and the hydraulic cylinder changing direction lead by the high frequent oil flow direction. To meet the needs of different operating conditions, overcome the strong swing problem of the clamping cylinder generated by tamping bar vibration and the wear of tamping bar by forced vibration, exciting technology of load sensing and stepless regulation of frequency and amplitude is the trend of tamping device vibration development.

Key words: Electro-hyraulic excitation, Exciting technology, Oscillating amplitude, Tamping device, Vibration frequency