Abstract: The invention concerns a rotary slide set for a hydraulic steering arrangement with an outer rotary slide and an inner rotary slide arranged in the outer rotary slide, and having in its surface tank grooves, which are, at least in predetermined rotary positions, connected with a low pressure connection, and at least one through-opening in its wall, each overlapping, at least partly, a tank groove. In a rotary slide set of this kind it is desired to avoid jamming between the inner and the outer rotary slides. For this purpose, surface recesses have been made at the remaining tank grooves to serve as balancing areas.

Abstract: A hydraulic vehicle drive, particularly for mobile hoisting platforms, has a first pair of wheels drivable by first wheel motors in dependence of a first control valve and a second pair of wheels provided with second hydraulic motors. A switching arrangement short-circuits the second hydraulic motors in the driving-free state and for cooling supplies them with a flushing flow. In the driven state a second control valve, in dependence of which the second hydraulic motors are drivable, is activated, and if required connected with the first control valve. Thus, optionally, the first wheel pair can be driven alone or together with a certain driving output from the second wheel pair.

Abstract: A hydraulic valve arrangement with locking and floating function, with a control valve (9), which, for two operating positions (11, 12) connects one motor connection (A) with a pump connection and a second motor connection (B) with a tank connection and vice versa, in a floating position (13) connects both motor connections (A, B) with the tank connection and in a locking position (10) separates both motor connections (A, B) from the pump and tank connections. Further, there are two closing valves (16, 17), each being connected between the control valve (9) and a motor connection (A, B) and each having a piston loaded by a spring and limiting a spring chamber, the spring chambers being pressure releasable. Characteristic of this valve arrangement is that lifting valves (18, 19) are provided for the pressure release, which valves are operated by a control pressure depending on the position of the control valve (9). This improves the operating reliability.

Abstract: A hydraulic machine with an orbiting displacement element connected unrotatably with an output shaft via an intermediary shaft, the intermediary shaft having at least at one end an external toothing, which engages an internal toothing, which permits a swivel motion of the intermediary shaft. The external toothing has teeth with concavely shaped tooth sides having a smaller curvature at the axial ends than in the area of the axial center.

Abstract: A hydraulic steering device is disclosed, having a housing in which an inner control slider and an outer control slider are arranged so that they are rotatable relative to one another and which together are arranged as alterable flow path means between a supply connection arrangement and a working connection arrangement. In such a steering device it is desirable to produce a remote control facility of simple construction. To that end, each control slider is connected to a driving slider, and between the two driving sliders there is created at least one pressure chamber which is acted upon by fluid under pressure, and a change in volume of the pressure chamber effects a relative displacement of the two control sliders.

Abstract: The invention concerns a hydraulic motor (1) having at least one gearwheel set section (2), a supply section (3) and a front section (4) on which an output arrangement (15) can be fixed, the sections (2 to 4) being connected with each other in the axial direction by fixing bolts (11).It is desired to simplify the production and the service during operation for such a motor.For this purpose several bores (17) are provided, which penetrate the motor (1,) from one axial end (21) to the other, in which connection bolts (6) are arranged, which are provided with an engagement area (18) on the side of the front section (4).

Abstract: A hydrostatic steering device having substantially identical first and second steering systems, each including a pump connected to a steering unit, which is connected to a steering motor by two motor hoses. A steering wheel is common to both steering units. The device includes a change-over valve which has an operation position hydraulically coupling together the two motor hoses of the second steering system, while hydraulically isolating from each other the two motor hoses of the first steering system, and an emergency position hydraulically coupling together the two motor hoses of the first steering system, while hydraulically isolating from each other the two motor hoses of the second steering system. A switching device switches the change-over valve from the operation position to the emergency position, when a fault occurs in the first steering system.