Abstract: A mechanical lubricating pump for supplying lubricating oil to rotary parts of machines and equipment. A rotatable distributor is inserted in the lengthwise direction of a pump body, and a suction port and a discharge port are provided in the diametrical direction of the body. A worm gear is disposed at one end of the distributor, while a plunger is inserted at the other end. Upon rotation of the distributor, the plunger executes relative movements in the axial direction, so that the pumping action is effected to suck and discharge the lubricating oil. The distributor has means by which the roles of the suction port and the discharge port at the time of the forward rotation of a driving source are maintained as they are when the driving source is reversely rotated.