Abstract: The present disclosure relates to a foldable truss boom section, a truss boom and a crane. The foldable truss boom section includes: two chords that do not intersect with each other; at least two slideways fixedly disposed on each of the two chords, wherein each of the at least two slideways has at least two slideway fixing points; and at least two long web members connecting the two chords, wherein each of the at least two long web members has at least one sliding end which is slidable along the slideway and connected to the slideway at one of the at least two slideway fixing points, so that a cross-section state of the truss boom section is changeable.

Abstract: Power equipment, a driving device of trench cutter, and a trench cutter are disclosed. The power equipment comprises a motor, a motor installation seat with an inner cavity having a first installation hole and a second installation hole in respective ends, and a transmission shaft. The motor, at the upper part of the seat, is sealingly connected with the seat. A motor output shaft extends into the inner cavity through the first installation hole. One end of the transmission shaft extends into the inner cavity through the second installation hole and is drivingly connected with the motor output shaft. The middle part of the transmission shaft and the second installation hole are sealingly connected; the other end of the transmission shaft extends from the second installation hole. A motor oil drainage cavity can be sealed by sealing the seat without changing the structure of the motor without a lip seal.