Abstract: A gyratory crusher for comminution of material fed into the crusher. The gyratory crusher includes an upper crusher frame for supporting one or more wear parts. The upper crusher frame is configurable between an operation mode and a rotation mode. The gyratory crusher further includes a lower crusher frame, wherein the upper crusher frame in the operation mode is in engagement with the lower crusher frame. The gyratory crusher further includes a rotation device configured to rotate the upper crusher frame in relation to the lower crusher frame. The rotation device includes a gear ring configured to be rotatable relative to the lower crusher frame around a vertical axis. A method, and a retrofitting kit, for rotating an upper crusher frame of a gyratory crusher relative to a lower crusher frame of the gyratory crusher are also disclosed.

Abstract: The present disclosure relates to a monitoring system for a hydraulic system in a comminution apparatus including at least one pressurized accumulator. The monitoring system includes at least one pressure sensor and a control unit, wherein the pressure sensor is connected to the control unit. The pressure sensor is arranged to measure a pressure in the at least one accumulator and the control unit is configured to determine that a pressure in the accumulator is outside of a predefined range. The control unit is further configured to control a pressure regulating system that is arranged to restore the pressure in the pressurized accumulator.