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Dobbel Drum Winches
Motors The workhorse of our AHT winches is the radial piston hydraulic motor. This motor has up to 98 % volumetric efficiency under ideal operating conditions. It has proven to function well in many tough applications in In both heavy landbased industry and in the offshore industry. The motors are fitted with custom made load holding manifolds which have several functions. The manifolds will close the lift side if the pressure in the lowering side comes down to a pressure where cavitation could occur. This ensures that the load is held if a pipe is ruptured and also makes sure that the motors never can cavitate. In addition to the load holding function, the manifolds are equipped with a free-wheeling function that can rapidly let the motor rotate freely without any torque being transferred. The manifold also includes pressure relief functions and boost pressure inlet.
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Triple Drum Winches
flow from the HPU can be used by fewer motors, creating a higher rotational speed. This is very useful if a light load is being used or if the wire without load needs to be rapidly raised from the seabed. The motors active in different steps are changed automatically to have an even wear of all components. The gearing is fail-safe and does not allow activation if the actual load is too high for the requested gear step. Safety Safety is a key issue. The hydraulic system has several safety features and important functions which are backed up by battery power and sometimes by energy stored in accumulators. All critical functions are hardwired to work even if the control system for some reason is inoperable.
Main control valve The motors are being controlled by a high response industrial proportional valve. This very fast and accurate valve enables us to control the rotational speed and requested pressure acting on the motors. Gear steps The free-wheeling function is also used to create different gear steps. By disconnecting one or a number of motors, the entire 9