Oil injection apparatus

An oil injection apparatus comprising:

• a storage unit for extruding lubricating oil stored therein through an ejection hole formed therein;
• a discharge unit adapted to communicate with the storage unit through the ejection hole and discharge the lubricating oil supplied from the storage unit out of the discharge unit in reply to a pumping operation;
• a plurality of discharge pumps arranged at intervals and extending in a radial direction of the discharge unit, each of said discharge pumps having a piston slidably coupled to a cylinder, wherein the piston is positioned at a radially inner side of the discharge unit and includes at least one intake hole for taking the lubricant oil therethrough, and wherein the cylinder is positioned at a radially outer side of the discharge unit and has an oil discharge port at a distal portion thereof, the cylinder and the piston being in fluid communication with each other and configured to discharge the lubricating oil through the discharge port of the cylinder upon operation;
• and
• a driving unit adapted to rotate relative to a central axis, the driving unit including a pressurizing rotor having an outer cam surface eccentrical to the central axis of the driving unit so as to sequentially press the pistons of the discharge pumps upon rotation, thereby causing the lubricating oil introduced through the intake hole of the respective pistons to be sequentially pumped out and discharged through the discharge port of the respective cylinders.