Abstract: A rotary trench excavator comprising a prime mover (1) pivotably connected to a movable frame (2) carrying a working member having the form of a system of drive rotors (9 to 11). To drive each such rotor (9 to 11), its interior accommodates a support frame (6) with support and guide rollers (7 and 8), and a drive mechanism. In order to ensure turning of each rotor (9 to 11) 180.degree., or of the entire system of rotors, there is provided an additional frame (4) connected to the frame (2) of the excavator and to each of the rotors (9 to 11) by way of detachable flanges (13 to 26).

Abstract: A bucket-wheel trench excavator comprising a prime mover and an excavating unit arranged to bear on a wheeled support. The frame of the excavating unit is connected to the frame of the prime mover by means of an intermediate frame and horizontal-pivoted joints. Displacement of the excavating unit between the working position and the transport position is effected by two hydraulic cylinders which, in conjunction with the frames, form at least one four-element linkage wherein the intermediate frame and the excavating unit frame are rigid members and the hydraulic cylinders are connected end-to-end. The effect kinematic connection between the two frames and the hydraulic cylinders, provision is made for a strut connecting the four-element linkage joints provided between the rigid frames and between the hydraulic cylinders.