Abstract: With a differential gearing having a spur gear construction, the compensating gears (31a, 31b) are installed in meshing pairs and are tightly enclosed by a housing (14) so that with meshing spur gears (22, 23) they can act as toothed pumps with pressure zones, with a locking moment being produced between the two driven shafts (2,3). A substantial increase in the locking moment is achieved in that the compensating gears constructed as pinions are disposed in a determined sequence on the circumference of the spur gears and also comprise along their face width partitions (32) which prevent a reduction in pressure along the toothing. As a result with an equal number of pinion pairs there is produced a number of pressure zones which is more than double and consequently there is an increase in the locking moment developed.

Abstract: A differential gearing, in which the torque introduced via an input shaft is distributed equally to two driven shafts, is constructed as a spur gear differential and has a pinion arrangement as the locking mechanism in which the pinions and spur gears work as geared pumps. The pump moment is directly the locking moment, with the hydrostatic pressure developed being reduced by precisely dimensioned clearances without any further control devices being required. A special arrangement of the pinions in a housing guarantees an equal locking moment in both directions of rotation.

Abstract: For the reduction of capacity losses and heating in hydrodynamic working circuits, especially retarders, caused by undesired air circulation in emptied condition, it is suggested to introduce a certain quantity of a blocking medium into the working chamber. This blocking medium may be operating fluid, air, or a mixture of both, and can be introduced radially from the inside, from the outside, or from the center. It forms a blocking film by rotation of the bladed rotor wheel, which substantially prevents the circulation of air from one bladed wheel to the other.

Abstract: A hydrodynamic retarder is revealed having a rotor blade wheel and a stator blade wheel each with two different types of blading, i.e. an inner blading enclosed by an outer blading. The two blade rings are provided with blades inclined in opposite directions. This allows said retarder to be operated in both directions of rotation. A particularly advantageous development of the invention is that the retarder is operated as a counter-rotating retarder, whereby the stator is rotated in the opposite direction by means of a reversing gear. Thus, a vehicle can be hydrodynamically braked almost to standstill. When integrating the retarder into a rail vehicle, the rotor can be driven by the wheel sets separately from the stator. An identical braking effect is obtained in both directions of travel.

Abstract: The invention relates to a hydrodynamic retarder having two independent operating circuits. Opposite a double rotor on the one hand is a stator fixed to a housing, and the rows of vanes concerned are inclined. The other half of the rotor forms with a rotatable stator and a second operating circuit having rows of blades equally effective in both rotational directions. The stator of this second operating circuit can be coupled via a gear unit and a coupling device to the retarder shaft. The gear unit drives the stator in a direction opposite to the direction of rotation of the rotor and with step-up transmission. When braking from a high travelling speed, only the first operating circuit is effective, the stator of the second operating circuit is released by the retarder shaft and freely rotates as well without any braking action.

Abstract: The disclosure concerns a hydrodynamic control coupling with a primary drive vane wheel and a secondary driven vane wheel which together define a toroidal working chamber. Each vane wheel carries an array of vanes on its interior which extend toward the vanes of the other vane wheel. The vanes of the vane wheels are inclinded with respect to the axis of the coupling, yet each is oriented parallel to a respective radius of the coupling. Furthermore, the vanes on each of the vane wheels are inclined to extend toward the vanes on the other wheel. There is a working fluid inlet to the working chamber. A working fluid outlet from the working chamber is through the secondary, driven vane wheel and is via a plurality of bores extending tangentially toward the axis of the coupling. An overflow valve communicates with the outlet from the working chamber. Upon the rotary speed of the primary vane wheel increasing rapidly, the overflow valve reacts by opening more widely, reducing the filling level in the coupling.

Abstract: The invention concerns a hydrodynamic torque transfer unit, particularly in the form of a hydrodynamic brake. Flow to the inlet of the working chamber of the transfer unit is controlled by an inlet valve movable between a closed, partially open and fully open position. A first piston moves the valve between its positions. A change over device cooperates with the first piston. The change over device includes a second piston. A first pressure chamber is defined between the first and second pistons. A second pressure chamber is defined behind the second piston. Initially, the first pressure chamber is pressurized, driving the first piston and thus the inlet valve to the fully open position. The second piston is moved by pressurization of the second pressure chamber to cut off pressure to the first pressure chamber and to instead cause communication between the first pressure chamber and the working chamber.

Abstract: A hydrodynamic brake is disclosed of a kind comprising a rotor bucket wheel and a stator bucket wheel in a housing and defining a torus-shaped working chamber and defining between them a bucket wheel gap. An outlet duct surrounds the perimeter of the rotor bucket wheel. A plurality of baffle type flow obstructions are provided about the periphery of the bucket wheel gap, and are movable into the bucket wheel gap and when the brake is not engaged. A small gap between the radially outermost part of the rotor bucket wheel and the housing is continuous with the outlet duct. A second duct connects the outlet duct and the space in which the baffle type flow obstructions are accommodated, thereby preventing unwanted movement of the flow obstructions into the bucket wheel gap while the brake is engaged.

Abstract: The disclosure contains a hydrodynamic torque transmitting unit particularly for a hydrodynamic brake. A working chamber that is filled with working fluid contains a stator and a rotor. An inlet valve controls inlet of fluid to the working chamber. A piston connected with the inlet valve selectively closes the valve. The piston initially opens the inlet valve fully for a surge of working fluid into the working chamber. In a stage I condition, valving and pressure chambers associated with the piston returns the inlet valve to an intermediate position reducing the inflow of working fluid into the working chamber after the initial surge. In a stage II condition, the pressure chambers remain continuously pressurized for holding the inlet valve in the condition of maximum supply of working fluid to the working chamber. Various piston arrays are described in different embodiments.