Quick-injection grease filling device

A quick-injection grease filling device for filling grease into a roller unit structure of a bearing, the bearing having an inner frame part and an outer frame part, the quick-injection grease filling device comprising:

• an oil cup having a closed cup bottom and an upper cup mouth, said oil cup having a straight inner peripheral wall extending between the closed cup bottom and the upper cup mouth, said oil cup having an interior that defines an oil-receiving tank, the oil-receiving tank adapted to hold the grease therein;
• a piston received in the oil-receiving tank and being driveable upwardly and downwardly in the oil-receiving tank, said piston having an oppression surface and a bearing placement surface facing opposite directions, said piston having a side ring surface connected to a periphery of the oppression surface and the bearing placement surface, wherein the bearing placement surface faces toward the upper cup mouth, the oppression surface facing toward the closed cup bottom, the oppression surface adapted to press on the grease in the oil-receiving tank, the bearing placement surface adapted to allow the bearing to be placed thereon such that the outer frame part of the bearing presses the bearing placement surface to define an enclosed and sealed grease filling margin, wherein the side ring surface has at least one sealing ring, the at least one sealing ring being slidably fitted on the straight inner peripheral wall, wherein a center of said piston has a plurality of through-holes extending through the oppression surface and the bearing placement surface;
• a detachable guide seat having a combination part and a screw hole, the combination part being attached to the upper cup mouth of said oil cup through a detachable assembly unit such that said detachable guide seat is attachable to or detachable from the upper cup mouth;
• a screw screwed into the screw hole of said detachable guide seat so as to be movable forwardly and backwardly, said screw having an inner end and an outwardly extending end, the inner end extending into said oil cup, the outwardly extending end extending out of the upper cup mouth, the outwardly extending end having a rotating drive part thereon;
• and
• an oppression part configured on an inner end of said screw such that said oppression part is movable forwardly and backwardly along with said screw, said oppression part adapted to press upon the bearing.