摘要 |
A tube motor having an electric motor which is placed in a tube and the electric motor is coupled to a screw transmission including two screws with different pitches and a guide rod, whose driven screw and guide rod are arranged in-line on the common axis and manufactured as a single piece, placed rotatable, axially immovable driven nut and in an immovable guide profile, the electric motor being fixed at one end of said stationary tube and the driven nut being rotatably but axially immovable coupled to the other end of the stationary tube; whereby the pitch of said driven screw is high enough that the whole screw transmission is self-locking with respect to an external torque. |