Abstract: A servo-controlled magnetic valve has a main valve (13) and a servo valve (14). The servo valve opens when, after an empty stroke, a solenoid plunger (7) entrains a slide member (23) that carries the servo closure member (20) and, as a result, pressure is released to the low pressure side (17) from a pressure chamber (25) on the side of the servo piston (24) that is remote from the main valve seat (15). The servo piston (24) is an annular piston that surrounds an insert (19) that carries the main valve closure member (18) and the servo valve seat (20) and which, during the operating stroke, entrains the slide member (23) by means of first stops (26) and the insert (19) by means of second stops (28). In that manner, it is possible to obtain sufficient opening of the main valve (13) and a small overall height of the magnetic valve while retaining an initial empty stroke of the solenoid plunger (7).

Abstract: A description is given of an adjustable hydrostatic axial piston machine whose angle can be varied by means of a servo-piston (9) to which actuating pressure can be applied and which is connected to an electrohydraulic control valve. The control valve has a control piston (15) and a control sleeve (22) which can be moved axially relative to one another. The control piston (15) can be axially adjusted with a stepper motor (10), and the control sleeve (22) is coupled mechanically or hydraulically to an adjusting mechanism (9, 7) for the angle for the purpose of feeding back the angle.

Abstract: A suction gas conduit (1) for a refrigeration compressor has a curved section (4) of the gas path (2), which connects an inlet section (3) of the gas path to an outlet section (5). A widening (11) in the form of a step (12) is located on the inner side of the curve of the gas path. The curved section (4) especially abuts, at the outlet end, a valve plate (7) of the compressor, which valve plate (7) has a suction gas opening (6). The outer side of the curve of the gas path (2) is unimpeded. The step height (H) is from 0.3 to 1.0 times, and the step length (L) from 0.2 to 1.0 times, the hydraulic diameter (d) of the outlet section (5). As a result thereof, the unavoidable recirculation flow is located in a position where its undesirable effect is limited.

Abstract: A method of manufacturing a hollow piston including: fixing a core insert formed of a non-metallic material in a desired location within a mold cavity, injecting a mixture of non-metallic binder material and metal particles into the cavity so as to surround at least a portion of the core insert and form a piston, and eradicating the core insert from the piston.

Abstract: A drive train comprises an internal combustion engine, a clutchless gearbox, which can be shifted by means of an electronic control unit and by means of actuating devices, without a mechanical synchronizing device, and a hydrostatic gearbox with a hydraulic pump and a hydraulic motor, which are connected in a closed circuit. The rotational speed of the hydraulic motor being controllable in dependence on a control signal to the adjusting device of the hydraulic pump and/or to the adjusting device of the hydraulic motor. The control unit calculates the control signal by means of setpoint input via an accelerator pedal or as a function of the rotational drive speed of the internal combustion engine, with shifting of the transmission stages being possible by means of the actuating devices.

Abstract: The invention concerns a connecting rod for a hermetic refrigerating compressor, in which the connecting rod forms the mechanical connection between a crank and a piston. The purpose of the invention is to reduce wear in the crank bearing of the compressor with simple means. This is obtained by reducing compressive stresses in the connecting rod by making a cut-out in the connecting rod near the crank bearing. The cut-out causes deflection of compressive stresses, so that they are distributed over a larger share of the crank bearing surface. Also the outer shape of the connecting rod is adapted, so that also here the compressive stresses are distributed over a larger bearing surface. This reduces the wear on the crank bearing of the compressor and increases the life.

Abstract: A loop flushing circuit for a hydrostatic transmission module includes a three position, three port pilot pressure operated loop flushing valve having a first inlet port fluidly connected to the first system pressure line, a second inlet port fluidly connected to the second system pressure line and an outlet port fluidly connecting the loop flushing valve to the case drain through a drain line having a drain orifice therein. A loop flushing and lubrication line fluidly connected to the drain line upstream of the drain orifice extends within the casing and has an open end directed toward the rotating elements of one of the pump and motor. The three position valve has an intermediate position operatively located between the opposite end positions. System pressure from at least one of the first and second system pressure lines is always routed to the loop flushing and lubrication line through the valve regardless of which of the three positions the valve is in.

Abstract: The invention concerns a machine arrangement with a first machine having a first rotation connection, a second machine having a second rotation connection, and a shaft for transmission of a torque, the shaft being unrotatably connected with both rotation connections. In this connection it is desired to minimize the effects of alignment errors on mounting the two motors. For this purpose the shaft (5) has, at least in one end, an external toothing (6) engaging with an internal toothing (8, 9) of the machine at this end, said external toothing permitting a swivel movement of the shaft (5), the teeth (10) of said external toothing (6) having concavely extending tooth flanks (11, 12), whose axial ends (15, 16) are less curved than their area of the axial centre.

Abstract: A variable displacement bent axis hydraulic unit includes a control mechanism having a control housing with a displacement feedback sleeve and spool connected by a spring. A computer controls a proportional solenoid fluid valve that is in operative fluid engagement with the end of the spool opposite its spring connection with the displacement feedback sleeve. The displacement feedback sleeve is urged by the spring into engagement with a cam member on the yoke of the bent axis unit.

Abstract: A special ball joint for servo piston actuation in a bent axis unit includes an elongated actuator rod having a substantially spherical external surface on a first end and a servo piston on a second end. Also included is a single-piece yoke adapted to carry a cylinder block and rotate about an axis of rotation. A socket having a substantially spherical surface is interposed between the yoke and the spherical surface on the rod such that the actuator rod rotates the yoke with forces residing in at least two planes when hydraulic pressure is applied to the servo piston. Two servo pistons and two such ball joints can be applied to the yoke to obtain rotation of the yoke which is up to greater than plus or minus 45° from a neutral position. The external surface on the first end of the actuator rod and the socket must be mating so as to provide freedom of movement. The socket can be incorporated into the yoke itself. The foregoing servo pistons are received in servo bores of a one-piece control housing.

Abstract: Electric bus arrangement (1) for DC-supply of power components, particularly for an inverter, having a first and a second plate (2, 3), arranged in parallel with each other, separated by an isolating layer (4), by which the first plate (2) connects first connections of power components (13) of a first group with first connections (23) of power components (14) of a second group, and the second plate (3) connects second connections of the power components (13) of the first group with second connections of the power components (14) of the second group. In such a bus arrangement an increase of the switching frequency is desired, however without the risk of damaging components due to overvoltage.

Abstract: A positive displacement hydraulic unit includes a housing having a chamber formed therein with a circumferential surface bounded by a pair of spaced apart end walls. A rotary element for displacing fluid rotatably mounts in the chamber. A layer of abradable coating material is positioned between an end wall of the chamber and the adjacent side wall of the rotary element so as to provide a near-zero side clearance for the rotary element and thereby high volumetric efficiency for the hydraulic unit.

Abstract: A filled hydraulic piston assembly includes a piston body having first and second ends and a compartment in the piston body extending inwardly from the second end toward the first end. The piston is filled with an insert element which is inserted into the compartment of the piston and then held therein by pushing an annular lip on the second end of the body inwardly and against the adjacent end of the insert element. The insert element is comprised of a material that is less dense than the material of the body but has a higher bulk modulus than hydraulic oil. Oil channels can be formed in a variety of shapes on or around the insert so that oil may flow through the filled piston. The piston insert element can be formed from a variety of materials, such as plastic, magnesium, aluminum or other nonferrous metals. The body is generally comprised of steel.

Abstract: A micromixer having a mixing chamber for mixing two fluids. The mixing chamber has a first inlet arrangement for the supply of a first fluid and a second inlet arrangement for the supply of a second fluid. The mixing chamber includes a wall along which the first fluid flows, and the second inlet arrangement has at least one opening in the wall. A projection is located on the wall adjacent to the opening and extending into the mixing chamber so that the first fluid flows around the projection and builds a boundary layer with the second fluid. Mixing takes place by diffusion through the boundary layer.

Abstract: The invention relates to a hydraulic steering arrangement (1) with a housing (4), in which an inner control slide (7) and an outer control slide (6) are arranged to be mutually rotational, forming together a variable flow path device between a supply connection device (P, T) and a working connection device (L,R), at least one pressure chamber (17) being arranged between two working slides (15, 16), connected with both control slides (6, 7), the volume change of said pressure chamber (17) causing the relative displacement, and with a measuring motor (10). In such steering arrangements a simple an inexpensive way of realizing a remote control principle is desired. For this purpose, an intermediary plate (14) is arranged between the measuring motor (10) and the control slides (6, 7), in which plate at least one fluid channel (18, 19) is arranged to form at least one part of a connection from the pressure chamber (17) to the outside.

Abstract: There is disclosed a hydraulic or pneumatic machine having a first displacement element (8) that is rotatable about an axis of rotation connected to a shaft (10) so as to rotate therewith, which shaft is mounted rotatably in a housing (2), and co-operates with a second displacement element (9). The structure of such a machine is to be improved. For that purpose, the housing (2) has a pocket (3) in which the displacement elements (8, 9) are so arranged that the housing (2) covers the displacement elements (8, 9) axially on both sides (4, 5) at least in a working region and in the circumferential direction over a maximum of 180°.

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 steering device, in particular for vehicles, is disclosed, having a housing in which two sliders are arranged to move relative to one another and together form at least one adjustable throttle, a restoring device for restoring the two sliders to their neutral position being provided, one of the two sliders being driveable and the other of the two sliders being in operative connection with a measuring device. In such a steering device it is desirable to improve the correlation between steering torque and flow amplification; in particular it is desirable to linearize the relationship better. For that purpose the measuring device is arranged in a flow path closed in itself, and operates as a pump, while an open flow path runs past the closed flow path from an inlet connection arrangement to an outlet connection arrangement.

Abstract: A solenoid valve comprising a coil surrounding a guide for an armature, the armature being movable in the guide through magnetising of the coil or by means of a return mechanism, and a valve seat co-operating with a closing member for selective opening or closing of a valve opening through the valve seat controlled by the armature movement. As the closing member is a separate device in relation to the armature, which closing member is activated by the armature movement to a rocking movement around a contact point with the valve seat, an normally open or normally closed solenoid is obtained.

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.