Disclosed are a power transfer device for transferring external power to a rotary body, a pipe cutting device using the power transfer device and a hydraulic chucking device using the power transfer device. The power transfer device is configured to transfer external power to a rotary body coupled to one side of a main body. The power transfer device includes at least one double-action interlocking cylinder mounted to a rear surface of the rotary body and provided with a rod protruding toward the main body, a push unit installed in the main body and provided with at least one pusher protruding toward the rotary body, and a bearing disposed between the pusher of the push unit and the rod of the interlocking cylinder and configured to allow relative rotation of the pusher and the rod and to transfer power between the pusher and the rod.

A method for processing profile beam parts includes providing a machining station, an in-feed transport system, and an out-feed transport system. The method further includes transporting and in-feeding a first profile beam part together with a second profile beam part to the machining station, machining at least the first profile beam part in the machining station, out-feeding the first profile beam part with the out-feed transport system from the machining station to an intermediate position which is at a variable distance X from a discharge position between the machining station and the discharge position, and in-feeding the second profile beam part in the machining station with the in-feed transport system over a distance Y and simultaneously out-feeding the first profile beam part over the distance X from the intermediate position to the discharge position. The capacity of the system is improved with the method.