The invention discloses an automatic
grease-
injection device of a bearing. The automatic
grease-
injection device of the bearing comprises a driving belt,
grease discharging thin pipes, a grease storing box, a T-shaped supporting frame and an air pressure adjusting valve. Bearing grooves are fixedly arranged on the driving belt, the T-shaped supporting frame is arranged on one side of the driving belt, and an upper
piston bucket is arranged on one side of the bottom of a cross beam of the T-shaped supporting frame. The upper
piston bucket is connected with a lower
piston bucket through an inner double-end
piston rod, a pneumatic pump is connected with the lower portion of an
electromagnetic valve, and the air pressure adjusting valve is arranged in the middle position between the
electromagnetic valve and the pneumatic pump. According to the automatic grease-
injection device of the bearing, the bearing is subjected to grease injection by combination of
automatic transmission and quantitative grease injection. The driving belt can enable the grease injection of the bearing to be streamlined, grease-injection efficiency is improved, and manual cost is reduced. The grease discharging thin pipes distributed in a ring shape, an
infrared detector and the air pressure adjusting valve can enable fat to be injected between the inner ring and the outer ring of the bearing evenly, accurately and quantitatively, so that a reject ratio of the grease injection is reduced.