A torque anchor intended to block the rotation of a production string with respect to a casing of a well, the torque anchor comprising a body, at least two supports mobile with respect to the body, wheels borne by the supports, the wheels being suitable for running on an inner face of said casing, at least one restraining device suitable for exerting a force on said wheels in order to anchor said wheels in said casing.Each restraining device comprises a set of springs suitable for acting on the set of said supports and a guide capable of guiding said set of springs; said guide being borne by said supports; said guide being mobile with respect to at least one support.