Clearance eliminating device of guide screw rod

The utility model discloses a clearance eliminating device of a guide screw rod, which mainly solves the problems that the transmission process of a lower beam of the existing testing machine is not stable, and axial clearances exist during the stress. The device comprises a moving beam and a screw rod; the screw rod is arranged on the moving beam; a screw is arranged on the outer side of the screw rod; a worm wheel is arranged on the outer side of the screw; a compression nut is arranged at the top end of the screw; a bolt is arranged on the compression nut; a clearance eliminating nut is arranged on the inner side of the compression nut; a guide pin is arranged between the clearance eliminating nut and the screw; a spring is arranged above the clearance eliminating nut; and a turnbuckle is covered on the outer side of the spring. When the screw rod rotates and is stressed upward, the moving beam is lifted upward all the time, a lower combined surface of threads of the screw contacts with an upper combined surface of the screw rod all the time, the clearance between a screw rod pair is eliminated, the whole rigidity of the testing machine can be improved, the device is stable in transmission, and the effective dynamometry scope of the testing machine is enlarged.