Abstract: The present invention relates to a self-propelled surface milling machine, preferably in the form of an asphalt-milling machine, snow-milling machine or Surface Miner, having a mill roll which is drivable about a rotational axis, and a mill roll drive comprising an electrical motor which is accommodated within the mill roll, wherein stator and rotor of the electrical motor are accommodated within a dust and air-tightly sealed motor housing. It will be suggested to associate a cooling device comprising a closed circuit liquid cooling system to the electrical motor located within the milling roll body. Due to the high heat capacity of a suitable coolant, such as oil or mixed water and glycol small volume flows and hence small conduit cross sections will be sufficient. On the other hand, any incorporation of dust into the mill-roll drive as well as any formation of dust by discharge air can be avoided by the closed form of the circuit liquid cooling system.

Abstract: The present invention relates to an electric machine with a machine housing, in which a rotor and a stator winding are accommodated, wherein the stator winding includes winding heads arranged on opposite sides each in a winding head space, and with a cooling device which includes a liquid cooling circuit with a stator jacket cooling and cooling coils as well as a fan connected with the rotor for circulating air in the machine housing. The invention furthermore relates to a method for cooling such electric machine. In accordance with the invention it is provided that the cooling coils extend through the winding head spaces outside the winding heads and the fan includes two fan wheels each associated to a winding head space for generating an air flow circulating inside each winding head space, which by means of air duct and/or guiding means in the respective winding head space is circulatingly passed over the exposed cooling coils and through the winding heads.

Abstract: The present invention relates to a winch for elevating plant, in particular cranes, cable-operated excavators and similar construction machinery, comprising a hoisting drum, an electric motor for the drive of the hoisting drum which is received in the interior of the hoisting drum as well as power electronics and/or control electronics for the electric motor comprising at least one frequency inverter and/or frequency converter. In accordance with the invention, the power electronics and/or control electronics for the electric motor are received at least partly in the interior of the hoisting drum. Not only short cabling distances are hereby achieved; interference emissions with negative effects on the electromagnetic compatibility are avoided; and voltage overshoots impairing the service life of the inverter and the motor are reduced, but also a particularly compact construction of the winch is achieved.

Abstract: A method of controlling an hydraulic activation unit includes the steps of using a characteristic diagram of a first hydraulic transformer as an input variable in the control unit; using a characteristic diagram of a second hydraulic transformer as an input variable in the control unit; and activating the hydraulic actuator responsive to the input variables. The hydraulic activation unit includes the hydraulic power unit, such as a hydraulic actuator or a hydraulic motor, for producing a force. The first hydraulic transformer is operably connected to a first side of the actuator for supplying a pressure. The second hydraulic transformer is operably connected to a second side of the actuator for supplying a pressure. The control unit for assessing the first and second hydraulic transformer operably activates the hydraulic actuator.