The invention relates to a rotary drive for a drum in a winch on a support frame that has two parallel rotary piston motors that can be operated independently, each of which has a housing and a shaft. The housings are each connected to the drum for conjoint rotation. There is a reversible freewheel coupling between the shafts and the support frame in the force-transferring path, with which the respective shafts can be connected to the support frame for transferring forces.

Wind energy systems, such as an Airborne Wind Turbine (AWT), may be used to facilitate conversion of kinetic energy to electrical energy. An AWT may include an aerial vehicle that flies in a path, such as a substantially circular path, to convert kinetic wind energy to electrical energy. The aerial vehicle may be coupled to a winch assembly via a tether. The winch assembly may include a winch drum and a drum door. The winch assembly may be configured such that the drum door may operate in two or more positions, such as an open position and a closed position, to reduce the likelihood of stability problems occurring at the aerial vehicle during winding or unwinding of the tether.

Wind energy systems, such as an Airborne Wind Turbine (AWT), may be used to facilitate conversion of kinetic energy to electrical energy. An AWT may include an aerial vehicle that flies in a path, such as a substantially circular path, to convert kinetic wind energy to electrical energy. The aerial vehicle may be coupled to a winch assembly via a tether. The winch assembly may include a winch drum and a drum door. The winch assembly may be configured such that the drum door may operate in two or more positions, such as an open position and a closed position, to reduce the likelihood of stability problems occurring at the aerial vehicle during winding or unwinding of the tether.

A pneumatic load balancing system comprises a pressure sensor for determining the pressure in a chamber of the actuating cylinder, and a controller for controlling the air pressure in the chamber of the actuating cylinder via at least one air supply valve. The controller is configured to during a load balancing sequence continuously or periodically obtain a current air pressure in the chamber from the pressure sensor when supplying air to the chamber via said at least one air supply and to determine a balancing air pressure in the chamber when, if air fed to the chamber, the air pressure stops increasing or when the gradient of the pressure increase is below a pre-determined threshold value; or if the air pressure is let out from the chamber, the air pressure starts to decrease. The balancing air pressure thus determined is then used as the balancing air pressure for the actuating cylinder of the pneumatic load balancing system. Hereby an automatic setting of the air pressure required for load balancing can be achieved. The user does then not need to manually feed the required air-pressure and the system will use the correct air-pressure and mistakes in setting of the air pressure can be avoided.

A winch control system for off-road mobile construction or forestry equipment that includes a designated cab or operator platform area for operating the off-road mobile construction or forestry equipment is disclosed herein, the winch control system may include an input device. The input device may include a control interface and may be configured to control one or more functions of a winch in response to user interaction with the control interface. The input device may be portable and may be configured to be moved about the designated cab or operator platform area. The winch control system may be configured to enable operation of the winch when the input device is positioned within the designated cab or operator platform area and such that the input device is unable to control the one or more functions of the winch from a location beyond the designated cab or operator platform area.