Abstract: In the case of a wind power installation with at least one wind turbine and one current generator device, the current generator device has at least two generators. The generators are coupled to one another via at least one differential gear unit, the wind turbine being arranged on a balancing gear of the differential gear unit. The rotors of the generators are in each case connected to an axial gear of the differential gear unit, the stators of the generators being connected to one another to form an abutment on which the differential carrier of the differential gear unit is accommodated such that it can rotate.

Abstract: The invention relates to a cutting machine, in particular a tread cutting machine, having at least one cutting blade (8) linearly traversable on a blade carriage (1) for achieving a feed movement and rotationally driven by a motor (2), the motor (2) for the drive of the cutting blade (8) being arranged outside the blade carriage (1), and a torque-transmission means, which comprises a means for transmitting tensile forces, being provided between the motor (2) and the cutting blade (8), and that part of the torque-transmission means which is traversable with the blade carriage (1) having a markedly lower mass than the motor (2). In this case, the motor (2) is provided with a device which is designed as a closed-loop control or an open-loop control and is intended for keeping the rotational speed of the cutting blade (8) at least approximately constant during a feed movement of the cutting blade (8).

Abstract: The invention relates to a sintered material as friction material for a pole shoe, a pole shoe area or at least an area of the pole shoe friction surface of a magnetic track brake (300), more particularly an eddy current brake and/or magnetic track brake with a magnetic basic and/or carrier member.

Abstract: A sintered material is used as a friction material for a pole shoe area of a magnetic track brake, having at least one of a magnetic basic member and a carrier member. The sintered material contains at least one of a proportion of pulverized wear inhibitor and a proportion of powder forming a protective layer.

Abstract: A pole core with pole lips serves for fixing a field winding in the pole housing of a direct current motor. The pole core has a central pole body mountable on an inner side of the pole housing. The pole lips are formed of one piece with the central pole body and are resiliently and springily connected to the central pole body, so that the field coil can be pressed against the pole housing in an elastic springy manner without additional spring elements, so that no damage occurs to the insulating coat of the coil.