Abstract: A high-speed drive shaft is connected to dredge pump shaft by a planetary gear, upon which a controlled speed is superposed, by branching power off the high-speed shaft for driving an auxiliary adjustable pump which, in turn, runs a hydrostatic motor whose rotary output is connected to the ring gear of the planetary gear via a transmission which includes two brakes and a speed-responsive clutch; one brake is also speed-responsive, the other one is responsive to motor pressure, to provide a possibly redundant system for preventing torque transmission to the motor, e.g., in case of dredge pump blockage.

Abstract: A shaft carrying a cutter head is bolted to the output shaft of a speed reducer gear in coaxial configuration and having a casing journalled on the shaft. The casing carries plural drive motors and the gear has a combining stage as input. The shafts are mounted in thrust and pendulum bearings in a frame and the casing is held against rotation on that frame. The output stage of the gear is a planetary gear with a spider from which extends the output shaft and a hollow shaft and in opposite directions. The casing is journalled on the shaft by bearings engaging the hollow shaft and the output shaft at opposite sides of the spider.