Gyratory crusher, a method for rotating an upper crusher frame and a retrofitting kit

A gyratory crusher for comminution of material fed into the crusher, the gyratory crusher comprising:

• an active crushing member consisting of a main shaft, a crushing head and a mantle which mantle presents an outer surface against which material crushing is made;
• an upper crusher frame for supporting one or more wear parts, wherein the upper crusher frame defines a cone-shaped crushing chamber and is configurable between an operation mode and a rotation mode;
• a lower crusher frame;
• wherein the upper crusher frame in the operation mode is in engagement with the lower crusher frame to prevent movement between the upper crusher frame and the lower crusher frame and wherein the engagement is released between the upper crusher frame and the lower crusher frame in the rotation mode to allow movement between the upper crusher frame and the lower crusher frame;
• a top framework which spans the crushing chamber across its top said top framework including a spider containing a machined journal which fixes the position of the upper end of the main shaft;
• and
• a rotation device configured to rotate the upper crusher frame in relation to the lower crusher frame in the rotation mode, and wherein the rotation device comprises a gear ring configured to be rotatable relative to the lower crusher frame around a vertical axis, and wherein the upper crusher frame is engaged with the gear ring, and configured to rotate, in the rotation mode, together with the gear ring around the vertical axis.