Hydraulically actuated tool for mounting and dismounting rolling mill roll neck bearings

Apparatus for axially urging a bearing assembly into and out of a seated position on the neck of a roll in a rolling mill, wherein the roll neck has an end which protrudes axially from the bearing assembly when the bearing assembly is in its seated position, and wherein the bearing assembly includes an externally threaded ring having circumferentially spaced radially inwardly protruding lugs coacting in a bayonet connection with circumferentially spaced radially outwardly protruding lugs fixed with respect to the roll neck, the threaded ring being rotatable on the roll neck between an engaged position at which said inwardly and outwardly protruding lugs are aligned circumferentially to axially retain the threaded ring on the roll neck, and a disengaged position at which said inwardly and outwardly protruding lugs are offset circumferentially to accommodate axial removal of the threaded ring from the roll neck, with a lock nut threaded onto the threaded ring, the lock nut being engageable with first and second axial thrust components of the bearing assembly said apparatus comprising:

• a piston surrounded by a cylinder, said piston being configured to internally subdivide said cylinder into axially separated first and second chambers;
• attachment means for removably fixing said piston to the end of the roll neck;
• fluid means for alternatively pressurizing said first and second chambers to alternatively shift said cylinder with respect to the thus fixed piston in opposite first and second directions;
• first force exerting means responsive to shifting of said cylinder in said first direction for acting via said first thrust component to axially urge the bearing assembly into its seated position;
• and
• second force exerting means responsive to shifting of said cylinder in said second direction for acting via said threaded ring, said locknut and said second thrust component to axially urge the bearing assembly out of its seated position.