Abstract: An apparatus for improving the cooler efficiency of a hydraulic drive system in a self-propelled agricultural machine includes a constantly running hydraulic pump which is driven by an internal combustion engine and a diverting device. The hydraulic pump creates a constant circulating stream of hydraulic fluid that circulates separately from the working stream of hydraulic fluid of the system. The diverting device draws a partial stream of hydraulic fluid from the working stream to the cooler. The diverting device adjusts the size of the partial flow depending on the temperature of the constant circulating stream of fluid in order to allow the cooler to work continuously at optimum efficiency without exceeding the maximum permissible pressure in the system.

Abstract: The harvesting machine includes an attachment, a feed device for material to be harvested, a cutting drum for the material to be harvested, an ejection means for conveying the material from the cutting drum, an advantageously hydrostatic drive for the feed device, a drive for the cutting drum, respective rotation speed sensors for measuring actual rotation speeds of the cutting drum and the feed device and an electronic analysis unit.

Abstract: A hydraulic control valve formed as a magnet valve with several connections and switching positions, comprises a housing provided with several connections, a valve slider displaceable in the housing, an electromagnet provided with an extensible plunger for controlling the valve slider, a valve seat provided in the housing, a ball movable between a closing position and an opening position with respect to the valve seat, a closing spring which urges the ball to the closing position. The ball is bringable by the valve slider to the opening position under the action of a force of the electromagnet, a valve body is firmly but exchangeably inserted in the valve housing so that the valve slider is guided in the valve body. The valve body accommodates the valve slider, the ball and a closing spring which presses the ball against the valve seat. A plurality of conduits are provided, including a pressure conduit, a control conduit and a consumer conduit.

Abstract: An agricultural harvester has a drawing-in device, a main drive provided with a main drive shaft, an auxiliary drive having a hydraulic motor, a turning arm supporting the hydraulic motor and turnable about a stationary axis extending parallel to the main drive shaft, positioning member arranged so that the turning arm is turnable by the positioning member in two end positions, the hydraulic motor having a driven pin, a pinion having spur teeth and fixed on the driven pin of the hydraulic motor, a drive spur gear fixed on the main drive shaft, so that the turning arm is turnable by the positioning member so that the pinion engages with the drive spur gear and disengages from the latter.

Abstract: A control device with a steering control block in which four hydraulic control valves, controllable in pairs by means of a spool valve, together with reversing valves, adjustable by the spool valve, are disposed and are connected with forward and reverse controlling control connectors of a right and a left drive. The spool valve is activated by a steering wheel and a drive lever; the drives are differentially charged in an analog steering sense. The control device is suitable for tracked vehicles.