The invention relates to a system for changing the hammers of a shredder including a shredder with one or more covers and a rotating drum equipped with a plurality of hammers; a lifting system suitable to move said hammers and a control unit which controls both the opening of the shredder and the movements of the lifting system and preferably also the unlocking/locking of the hammers from/on the drum to allow their replacement. The system can be managed hydraulically with a single hydraulic supply. It is included to be able to control the system remotely or to include its automation according to a maintenance plan. A relative method for changing the hammers of a shredder is also disclosed.

A rotor positioning device in a crusher is arranged to adjust a rotational position of a rotor shaft. A shaft engager includes a female toothed mating surface for coaxial engagement with a male mating surface at an end of the rotor shaft, so they become rotationally interlocked. The shaft engager includes alignable indicator slots that are, when in use, alignable with markings associated with an end of the rotor shaft, such that the markings become visible through the slots as the rod is rotationally driven by a drive component. The markings correspond to hammer positions within the crusher, such that these can be maneuvered for maintenance (e.g. to top dead-center positions) before access to the crusher chamber is gained.

A rotor locking device in a crusher is arranged for locking a rotational position of a rotor shaft. A shaft engager includes a female toothed mating surface for coaxial engagement with a male mating surface at an end of the rotor shaft to rotationally interlock the same. A fastening portion with engager apertures overlaps with a bearing mount surrounding the rotor shaft so it can be fastened therewith. The engager apertures are circumferentially elongated in order to accommodate alignment with fastening points in the bearing mount, at least when a closest rotational mating position is chosen for alignment. This enables any rotational position of the rotor shaft to be locked for safety before having to access the crusher chamber, especially when the rotor of the crusher has become blocked and requires maintenance.

A hammer mountable at a rotor of a horizontal shaft impact crusher (HSi-crusher), the hammer including a front face, a rear face and at least one recess projecting inwardly into a main body of the hammer from the front face. The at least one recess being arranged to receive an attachment element to mount the hammer at a hammer lifting device.

Improved free-swinging hammermill hammer configurations are disclosed and described for comminution of materials such as grain and refuse. The hammer configurations of the present disclosure are adaptable to most hammer mill or grinders having free-swinging systems. The configurations as disclosed incorporate comminution edges having increased hardness for longer operational run times. The improved configurations improve installing, removing, and cleaning hammer components within the hammermill. More particularly, a method for replacing hammers and spacers includes pre-assembling hammers, spacers, hammer saddles, locking collars, or any combination thereof and temporarily attaching them to one another before placement onto a hammermill rod. Once placed on the hammermill rod, the temporary attachment is broken such that the hammers within the pre-assembled group may move freely with respect to one another.

A rotor locking device in a crusher is arranged for locking a rotational position of a rotor shaft. A shaft engager includes a female toothed mating surface for coaxial engagement with a male mating surface at an end of the rotor shaft to rotationally interlock the same. A fastening portion with engager apertures overlaps with a bearing mount surrounding the rotor shaft so it can be fastened therewith. The engager apertures are circumferentially elongated in order to accommodate alignment with fastening points in the bearing mount, at least when a closest rotational mating position is chosen for alignment. This enables any rotational position of the rotor shaft to be locked for safety before having to access the crusher chamber, especially when the rotor of the crusher has become blocked and requires maintenance.

A rotor positioning device in a crusher is arranged to adjust a rotational position of a rotor shaft. A shaft engager includes a female toothed mating surface for coaxial engagement with a male mating surface at an end of the rotor shaft, so they become rotationally interlocked. The shaft engager includes alignable indicator slots that are, when in use, alignable with markings associated with an end of the rotor shaft, such that the markings become visible through the slots as the rod is rotationally driven by a drive component. The markings correspond to hammer positions within the crusher, such that these can be manoeuvred for maintenance (e.g. to top dead-center positions) before access to the crusher chamber is gained.

Improved free-swinging hammermill hammer configurations are disclosed and described for comminution of materials such as grain and refuse. The hammer configurations of the present disclosure are adaptable to most hammer mill or grinders having free-swinging systems. The configurations as disclosed incorporate comminution edges having increased hardness for longer operational run times. The improved configurations improve installing, removing, and cleaning hammer components within the hammermill. More particularly, a method for replacing hammers and spacers includes pre-assembling hammers, spacers, hammer saddles, locking collars, or any combination thereof and temporarily attaching them to one another before placement onto a hammermill rod. Once placed on the hammermill rod, the temporary attachment is broken such that the hammers within the pre-assembled group may move freely with respect to one another.

A rotor of an impact crusher may include a crushing roll body and at least one holding device that is mounted on the crushing roll body and is configured to hold a blow bar. The holding device may have a guide frame and at least one guide element. The guide element may be connected to the blow bar and may be movably mounted on the guide frame such that movement of the guide element relative to the guide frame in a radial direction results in movement of the blow bar relative to the crushing roll body in the radial direction. The guide element can be arranged so as to be movable in an axial direction relative to the blow bar.

A crusher hammer lifting device facilitates raising and lowering of a hammer mountable at a rotor of a horizontal shaft impact crusher (HSi-crusher). The device includes a main body, a mount engager for attachment to an auxiliary lifting tool and a hammer attachment for releasably mounting the hammer in a rotatable manner at the device.