Ball screw with an oil-storage unit

A ball screw, comprising:

• a screw shaft extending in a direction to form an elongated structure, and the direction in which the screw shaft extending being defined as an axial direction;
• a nut formed with a threaded hole for enabling the nut to be screwed on the screw shaft, and a L-shaped fixing hole formed at an end surface of the nut, extending in the axial direction and being in communication with the threaded hole;
• an oil-storage unit including an oil tank and a connector, the oil tank including a mounting hole, a gap, a connecting end, and an oil-storage space, the mounting hole extends in the axial direction to penetrate the oil tank, and another direction normal to the axial direction being defined as a radial direction, the gap being formed by removing a radial part of the oil tank and in communication with the mounting hole, the gap having a width larger than an outer diameter of the screw shaft, the connecting end being in the form of a concave structure or a convex structure disposed at an end surface of the oil tank and formed in the axial direction with a penetrating hole in communication with the oil-storage space, the connector including a first end, a second end, and an oil feeding hole running through the first and second ends, the first end being inserted in the axial direction and into the fixing hole of the nut, and the second end being connected to the connecting end of the oil-storage unit, the oil-feeding hole having two ends in communication with the oil-storage space and the fixing hole, respectively;
• wherein the second end of the connector is in the form of a convex structure or a concave structure for engaging with the connecting end of the oil tank, so as to fix the oil tank to the connector;
• the oil tank is provided with two first positioning portions extending in the axial direction, and the nut is formed on an outer surface thereof with two second positioning portions for engaging with the first positioning portions.