Protective cover with improved coupler

The utility model discloses a protective cover with an improved coupler. The protective cover comprises a cover plate, a left bearing plate and a right bearing plate, wherein the lower portion of the left bearing plate and the lower portion of the right bearing plate are bent at 90 degrees, the left bearing plate is fixed to the left of the coupler, the right bearing plate is fixed to the right side of the coupler, the upper end of the left bearing plate is hinged to the lower end of one side of the cover plate, the upper end of the right bearing plate is connected with a lower screw on the other side of the cover plate, and one side face of the cover plate is provided with an operation handle. Firstly, a full-sealed cylindrical structure is formed, a high-speed rotating device can be isolated completely, and the structure is simple and attractive; secondly, after the screw at the lower end of the other side of the cover plate is disassembled, the cover plate can be rotated and opened, and accordingly the cou