Crusher, method for crushing material and method for controlling a crusher

A method for crushing material, in which method the material is introduced between a first rotary crushing blade and a second rotary crushing blade, and the second crushing blade moving linearly back and forth with respect to the first crushing blade, and the rotation axis of the crushing blades being parallel to the linear direction of movement, wherein the back-and-forth movement is substantially harmonic.

A method for controlling a crusher, the crusher comprising at least a first crushing blade and a second crushing blade which are arranged to be rotary, the second crushing blade being also arranged to move back and forth along a linear path, and the rotating axes of the first crushing blade and the second crushing blade being parallel with the linear direction of movement of the second crushing blade, wherein in the method, the second crushing blade is adjusted to move along a linear path substantially harmonically.