Dustproof protective cover

The utility model discloses a dustproof protective cover, relates to the technical field of oil pumping units, and aims to solve the problems that a belt runs for a long time and is loosened, and an existing protective cover only has a dustproof function and cannot adjust the tension of the belt, so that the belt slips, the working efficiency is low and the working efficiency is high in the prior art. In order to solve the problems that in the prior art, when a belt breaks, an alarm cannot be given out, and practicability is low, according to the scheme, a protective cover and a sealing plate are included, adjusting mechanisms are arranged on the inner wall of the top and the inner wall of the bottom of the protective cover correspondingly, and each adjusting mechanism comprises a mounting frame, three springs, three fixing frames and three extrusion rollers; and the mounting mechanism comprises two mounting blocks, a mounting pipe and a touch rod. The tension of the belt can be adjusted in real time, the sit