360-degree rotational cam hydraulic door closer for narrow frame door

A 360-degree rotational cam hydraulic door closer for a narrow frame door, the 360-degree rotational cam hydraulic door closer comprising:

• a door closer housing, the door closer housing being provided therein along an axis direction thereof with an inner chamber;
• a cam shaft, an axial direction of the cam shaft being perpendicular to an extending direction of the door closer housing, the cam shaft being 360-degree rotatably supported in the door closer housing, the cam shaft being equipped at a middle part thereof with an eccentric cam rotating simultaneously with the cam shaft;
• a bidirectional piston, the bidirectional piston being slidingly disposed in the inner chamber and located at a right side of the eccentric cam, a damping roller being rotationally disposed at a side of the bidirectional piston close to the eccentric cam;
• and
• a drive spring, the drive spring being accommodated in the inner chamber and abutted against the bidirectional piston and the door closer housing, the drive spring driving the damping roller to be consistently flexibly abutted against an outer peripheral surface of the eccentric cam;
• wherein the outer peripheral surface of the eccentric cam is provided clockwise in order with a left closing arc recess, an upper damping protrusion, a right closing arc recess and a lower damping protrusion;
• the left closing arc recess and the right closing arc recess are located on a same horizontal line;
• the upper damping protrusion and the lower damping protrusion are located on a same vertical line.