Jaw crusher, mineral material processing plant and method for processing mineral material

1. A jaw crusher comprising a fixed jaw and a movable jaw for forming a crushing chamber therebetween which is open at the top, the fixed jaw comprising a first wear part mounted thereto and the movable jaw comprising a pitman and a second wear part mounted thereto; wherein the pitman is rotatably mounted to a first eccentric shaft, wherein the pitman is further rotatably mounted to a second eccentric shaft configured to guide the stroke of the movable jaw to create a movement pattern with a linear crushing stroke, wherein the second eccentric shaft is positioned between the first eccentric shaft and the crushing chamber and the eccentricity of the second eccentric shaft is larger than the eccentricity of the first eccentric shaft.

2. The jaw crusher of claim 1 , wherein a horizontal line passing through the center of the first eccentric shaft passes through the lower or upper dead center of the second eccentric shaft.

3. The jaw crusher of claim 2 , wherein the horizontal line passing through the center of the first eccentric shaft passes through the middle section of the crushing chamber.

4. The jaw crusher of claim 2 , wherein the horizontal line passing through the center of the first eccentric shaft passes through the centerline of the crushing chamber thus dividing the crushing chamber into two parts of equal height (H).

5. The jaw crusher of claim 1 , wherein the second eccentric shaft is configured to swing back and forth in response to the first eccentric shaft rotating.

6. The jaw crusher of claim 1 , wherein the second eccentric shaft is mounted in such a way that the upper or lower dead center thereof is removed from the horizontal line.

7. The jaw crusher of claim 1 , wherein the first eccentric shaft and the second eccentric shaft are bearing-mounted to a body of the jaw crusher and to the pitman.

8. The jaw crusher of claim 1 , wherein the radius of the second eccentric shaft is between 2 and 4 times that of the radius of the first eccentric shaft.

9. A mineral material processing plant, wherein the mineral material processing plant comprises a jaw crusher of claim 1 .

10. A mineral material processing plant of claim 9 , wherein the mineral material processing plant is a mobile processing plant.

11. A method for processing mineral material comprising the steps of:

providing a jaw crusher including a fixed jaw and a moveable jaw that form a crushing chamber therebetween which is open at the top, the fixed jaw including a first wear part mounted thereto and the moveable jaw including a pitman and a second wear part mounted thereto, wherein the pitman is rotatably mounted to a first eccentric shaft and to a second eccentric shaft configured to guide the stroke of the moveable jaw to create a movement pattern with a linear crushing stroke, wherein the second eccentric shaft is positioned between the first eccentric shaft and the crushing chamber and the eccentricity of the second eccentric shaft is larger than the eccentricity of the first eccentric shaft; and

directing a linear crushing stroke to the material to be crushed in the crushing chamber by swinging the second eccentric shaft back and forth in response to the first eccentric shaft rotating.

12. The method of claim 11 wherein the jaw crusher is provided within a mineral material processing plant.