Abstract: A new type of shale shaker is presented，which is excited by three motor self synchronously. With big exciting force and equipped with no mechanical transmission, and low noise, simple structure, convenient production and maintenance, it can be applied on the shaker with big screening area especially. By building the mechanics model of this kind of Shaker，and using the Hamilton principle, the Selfsynchronism qualification and stability condition of the shaker system are built, and the conditions of the system can carry out uniform elliptical motion. Research results show that this kind of shale shaker can synchronously and steadily run when the selfsynchronism qualification and stability condition are satisfied. So it is of bigger theoridical and engineering applying value.

Key words: shaker, three motor excitation, selfsynchronism, stability, elliptical motion