Elastic floating guide rail for iron roughneck main and back-up wrenches

The invention relates to an elastic floating guide rail for iron roughneck main and back-up wrenches in the technical field of petroleum drilling. The elastic floating guide rail for the iron roughneck main and back-up wrenches comprises a main wrench and a back-up wrench which are coaxially arranged vertically; the main wrench and the back-up wrench are axially supported and positioned through a support block; a main wrench guide rail with an annular opening coaxial to a rotation axis of the main wrench is arranged on the lower surface of the main wrench; a back-up wrench guide rail which is matched with the main wrench guide rail is correspondingly arranged on the upper surface of the back-up wrench; a buckle oil cylinder drives the main wrench and the back-up wrench to relatively rotate along a matching surface of the main wrench guide rail and the back-up wrench guide rail; mutually matched circumference of the main wrench guide rail and the back-up guide rail are in rolling match through a plurality of elastic rolling wheels which are arranged on one of the guide rails in a rotation mode. According to the elastic floating guide rail for the iron roughneck main and back-up wrenches, deviation between a drilling tool center and a guide rail center is compensated through compressive deformation of the elastic rolling wheels when the main wrench and the back-up wrench rotate relatively and accordingly relative rotation of wrench heads is smoothly achieved and the guide rails are prevented from being blocked to rotate or clamped due to different centers.