Abstract: A hydraulic axial piston machine (1) is disclosed, having a cylinder drum (2), which has at least one cylinder (5) in which a piston (9) is arranged to move back and forth, and having a control plate (3), which on rotation of the cylinder drum (2) and control plate (3) relative to one another connects the cylinder (5), in dependence on its position, to a fluid inlet and a fluid outlet (4), a pressure plate (6) being arranged between the cylinder drum (2) and the control plate (3) and having for each cylinder (5) a fluid path (14) between the control plate (3) and the cylinder drum (2). It is desirable for such a machine to be capable of operation also with a hydraulic fluid that has no or only slight lubricating properties. To that end, the cylinder (5) is lined with a bushing (10) of a friction-reducing plastics material which projects from the cylinder drum (2) and is inserted in the pressure plate (6).

Abstract: Motorised head pulley comprising a rotating drum, which is driven by a permanently mounted hydraulic motor situated in the pulley. Between the motor and the pulley, a reduction gear is inserted. The motor and the reduction gear comprise moving parts, which are designed for operation in contact with a water-based, lubricant-free pressure fluid. The motorised head pulley can by this be used without having to pay attention to the risk of pollution from the hydraulic medium. The motorised head pulley is especially appropriate to drive conveyors in food processing production.

Abstract: A refrigeration system having at least one defrostable cold-production device is disclosed, beneath which device a drip tray provided with a drain channel is arranged. In such a refrigeration system, it is desirable to reduce the risk of flooding because of a blocked drain channel. For that purpose, a liquid sensor which detects the presence of liquid at a level above the drain channel is provided in the drip tray.

Abstract: A hydraulic axial piston motor is disclosed, having a rotatable cylinder drum, in which several work pistons, each provided at one end with a slider shoe, are arranged in work cylinders so as to be axially movable, having a control plate, a swash plate, against which the slider shoes bear, a pressure plate which holds the slider shoes on the swash plate, and a pressure-applying unit, which acts on the pressure plate and comprises a hydraulic piston-cylinder arrangement. Using such a motor it is desirable for an adequate contact pressure to be produced using simple means. For that purpose, the piston-cylinder arrangement is arranged between the cylinder drum and the control plate.

Abstract: A method for mounting a cylinder sleeve in a base member is disclosed, in which the cylinder sleeve is inserted in the base member and the outer diameter of the inserted cylinder sleeve is enlarged at one end, and a hydraulic machine with a base member in which at least one cylinder sleeve is arranged in a cylinder bore. In this connection, it is desirable to be able to use materials for the cylinder sleeve that could not previously be satisfactorily fixed in the base member. For that purpose, the cylinder sleeve is heated before the outer diameter is enlarged. The cylinder bore has at at least one end a gradual enlargement of diameter and the cylinder sleeve has an enlargement of its outer diameter matched to this enlargement of diameter.

Abstract: A radial journal bearing (5, 6) is indicated, with an interior bearing surface placed facing an exterior bearing surface, where one of the bearing surfaces comprises a slide shoe (7, 8), which has one end with a contact face loaded to contact against the other bearing surface, and where this end is movable in such a manner that the contact against the other bearing surface can be maintained by a relative displacement of the bearing surface at right angles to the direction of the load. Hereby it is achieved that the variation of the leakage between the slide shoe and the opposing bearing surface is essentially reduced, resulting in longer life and greater stability.

Abstract: A valve, especially a thermostatic expansion valve, has a setpoint spring which bears on a plate having a sloping face. A setpoint adjusting device is provided in a housing connecting tube. The adjusting device has a pressure-applying piece having a contact face engaging the sloping face, is secured against rotation and has a threaded bore. An adjusting screw which is supported on the connecting tube against axial displacement engages in this threaded bore. In this construction, the connecting tube requires no machining.

Abstract: In a device for controlling the pressure to be supplied to a hydrostatic steering unit (1) by means of a control signal (s), there is a rotary slide valve arrangement, one slide valve element of which is rotatable by means of a steering means (5) and the other side valve element of which is corrected by means of a measuring motor (16). Together with a series throttle (AV), a control throttle (AS) forms a series circuit independent of the intake path of the steering motor (4), which circuit is connected between a pressure source (CF) and the tank (6). The control throttle (AS) has a closing characteristic that extends substantially across the entire working range of the angle of rotation of the slide valve elements. The control signal (s) is tapped between the series throttle (AV) and the control throttle (AS). This provides a pressure control that is independent of load.

Abstract: A hydraulic system is proposed, with a pressure source (P), a pressure sink (T), a work motor (4), a main valve (3) which is arranged between the pressure source (P) and the pressure sink (T) on the one hand and the work motor (4) on the other hand and is connected to the work motor (4) by way of work connections (73, 74), and a compensating valve (2) between the pressure source (P) and main valve (3) and an additional valve arrangement (5) between the main valve (3) and the pressure sink (T), which controls the volume flow from the main valve to the pressure sink (T). In a system of that kind it is desirable to provide better control facilities. To that end, the valve arrangement (5) has an externally controllable degree of opening.

Abstract: A fully functional analyzing unit is included within the fluid-tight housing of a dialyzer which may be immersed in the medium to be analyzed. An opening in the housing is closed by a dialysis membrane. A channel defining body cooperates with the membrane to define a flow channel. The unit includes a carrier fluid reservoir and a carrier pump for generating a flow of carrier fluid through the flow channel. By dialysis via the membrane, the flow of carrier fluid is transformed into a flow of sample fluid which is received in a reaction channel. Reagent fluid from at least one reagent reservoir is delivered to the reaction channel by at least one reagent pump, and a detecting device is coupled to the reaction channel for detecting a reaction product originating from a reaction between the reagent fluid and the sample fluid and for generating a corresponding detection signal. Effluent from the reaction channel is received in a waste reservoir.

Abstract: A hydraulic piston engine driven by a lubricant-free, water-based pressure fluid, and comprising an enclosing housing and a piston-connected drive shaft supported by radial journal bearings in bearing bushings. One of the sliding surfaces of the radial journal bearing comprises a recess with a bearing-supporting hydrostatic pressure fluid pocket. The center of the recess is displaced by an angle (.alpha.) in the direction against the direction of rotation of the drive shaft, seen in relation to the geometrical, radial mean point in the high-load area for transmission of the piston forces to the bearing surface via the drive shaft. Hereby a particularly reliable piston motor of the type indicated is provided.

Abstract: A valve is indicated as well as a device for controlling the valve body in a valve, which is special in that the travel of the valve body in the valve housing is insignificantly damped in the opening movement of the valve, and strongly damped in the closing movement of the valve. The valve is therefore distinguished by the fact that especially in connection with pressure media with a low boiling point, the risk of cavitation in the valve and instability in operation is reduced.

Abstract: A fully functional analyzing unit is included within the fluid tight housing of a dialyzer which is immersed in the medium to be analyzed. An opening in the housing is closed by a dialysis membrane. A channel defining body cooperates with the membrane to define a flow channel. The unit includes a carrier fluid reservoir and a carrier pump for generating a flow of carrier fluid through the flow channel. By dialysis via the membrane, the flow of carrier fluid is transformed into a flow of sample fluid. A detecting device is coupled to detect an analyte in the sample fluid and for generating a corresponding detection signal. Effluent sample fluid is received in a waste reservoir. The device is suitable for in situ real-time measurement of plant nutrient salts in process waters of waste water treatment plants.

Abstract: A hydraulic axial piston machine is disclosed, having a cylinder drum which is mounted for rotation relative to a housing (1), with a bearing (3) having a slide face (4) being arranged between the circumference of the cylinder drum and the housing (1). It is desired that such a machine shall be capable of operating also with fluids that are not such good lubricants as hydraulic oil. For that purpose the slide face (4) is formed by a friction-reducing plastics material and has at least one recess (5, 6, 7) communicating with at least one end edge of the slide face (4).

Abstract: A measuring section for an electromagnetic flowmeter is provided having a metallic measuring tube made of a non-magnetic material, a set of magnetic coils for generating a magnetic field in a direction substantially at fight angles to the direction of flow, an electrode arrangement which is arranged substantially at fight angles to the direction of the magnetic field and substantially at right angles to the direction of flow, and an electrical insulator on the inside of the measuring tube, and also a method for the manufacture of this measuring section. Here, it is desirable for manufacture to be carried out with a relatively high degree of reliability. For that purpose, the insulator is constituted by a surface layer of metal oxide or metal nitride having a thickness of more than 10 .mu.m an on the inside of the measuring tube. The inside of the measuring tube can be oxidized or nitrogenized for that purpose and a metal oxide or a metal nitride is deposited on the resulting oxide or nitride layer.

Abstract: A controlled proportional valve is provided, with a main slide valve section (4) containing a main slide valve, which section controls a flow of fluid between a pump connection (P) connected to a pump (2) and a tank connection (T) connected to a tank (6) and two work connections connected to a load (5) and which generates a load-sensing signal (LS.sub.INT) in dependence on the pressures at the work connections (A, B), and with a compensating slide valve section (3) which controls the pressure across the main slide valve section (4) in dependence on the load-sensing signal (LS.sub.INT). It is desirable to achieve a more rapid response time in a proportional valve of that kind, wherein the control means should be capable of being retrofitted to existing proportional valves. To that end, a control arrangement (10) which controls the pressure of the load-sensing signal (LS.sub.INT) to influence the actual volume flow and/or the actual pressure in the work connections (A, B) is provided.

Abstract: A hydraulic machine is disclosed, with an annular gear with internal teeth and, eccentrically mounted in the annular gear, a gearwheel with external teeth which engage with the internal teeth, the internal teeth comprising one more tooth than the external teeth and the contour of the external teeth being formed by an envelope of a system of generating circles, the midpoints of which lie on a trochoid which, as a rolling circle rolls without slipping on a base circle, can be generated by the movement of a point lying on a radial ray of the rolling circle co-rotating with the rolling circle. A method of producing the contour of a rear wheel of such a machine is also disclosed. In such a machine it is desirable to realize a satisfactory inner seal and low Hertzian stresses. To that end, the spacing of the point from the midpoint of the rolling circle is larger than the radius of the rolling circle.

Abstract: A control valve is disclosed, having a housing which has an input port and an output port that are connected to one another by a flow path in which a throttling device is arranged. It is desirable for such a control valve to be able to hold a volume flow constant, irrespective of the load pressure at the output port. For that purpose, the throttling device comprises a series connection of a first throttle, the passage of which is externally adjustable, and a second throttle, the passage of which is adjustable in dependence on pressure.