Abstract: Gear pump with meshing gears enclosed by a pump housing, with bearing journals arranged on longitudinal axes and each projecting laterally away from the gears, wherein at least one of the bearing journals has, at least over part of its axial extension, a bearing journal diameter that lies in the range of 90% to 100% of a root diameter of the toothing of the associated gear. A toothing width (b) is at least twice the dimension of a distance (a) between the longitudinal axes, the toothing width (b) being an extension of the gears parallel to the longitudinal axes.

Abstract: A method of controlling a gear pump comprising two meshing gear wheels (11, 12), wherein the two gear wheels (11, 12) are driven via respective shafts (2, 3) each by a drive unit (7, 8). A current position of the one gear wheel (11, 12) is determined with respect to the current position of the other gear wheel (12, 11), and the current position of the one gear wheel (11, 12) is continuously adjusted with respect to the current position of the other gear wheel (12, 11) according to specified predefined operating conditions.

Abstract: Gearwheel pump, having a housing with at least two intermeshing gears with shafts supported by slide bearings lubricated with pumping medium (M) fed from a suction side to a pressure side, a return duct which leads pumping medium which flows outward through the plain bearing back to the suction side, and a valve (5) having a stationary part and a moveable part (20, 21). The valve (5) has a setting characteristic which runs, as a first approximation, linearly at least in one region, wherein the setting characteristic is defined by a differential pressure (?p) across the valve as a function of a setting path (x) in the valve (5) thereby significantly improving capability for setting the pressure in the transition region between the plain bearing and a dynamic seal of a driveshaft which is guided outward.

Abstract: In order to cool the slide bearing area for the slidable bearing of a gear pump shaft, a slide bearing bush with a slide bearing area and, in the case of the guiding-through of a shaft, a sealing area extends in one piece integrally to the outside, and a cooling-medium guiding system provided in the bush is connected from the outside. This eliminates all sealing problems for the cooling medium feeding to the slide bearing area.

Abstract: A gear pump comprises rotors disposed in roller bearings. For the delivery of very viscous polymer meltings, bearings surfaces of at least one of inner races, outer races of the bearings and bearing surfaces of roller elements are made of a steel with a high-temperature stability. Bearing takes place on material pairings consisting of one of S6-5-2 high-speed steel and silicon nitride Si.sub.3 N.sub.4. The roller bearings are either unlubricated or lubricated by a lubricant remaining in the bearing, preferably a solid-substance lubrication. A distance of supported shafts, from a gearwheel face to a supporting area of the shafts, determined by the outer contact point in the roller bearing, is smaller than twice the median diameter of the shafts therealong.

Abstract: To reduce squeeze pressure peaks on meshing rotors of a gear pump, recesses are molded into the product duct wall in the meshing area, on the delivery side and the suction side. The recesses are formed with spherical segments or other continuously curved surfaces.

Abstract: Apparatus and process for handling thermoplastic liquified material is disclosed. A system including an extruder feeding into a degasifying chamber is disposed upstream of a gear pump for pressurizing the material. The extruder gravity delivering, by way of a multiple-billet die, billets to the gears outside of the gear meshing area.

Abstract: A gear pump rotor assembly is disclosed. In order to prevent that the gear toothing is cooled in an unreliable manner, radial heat flow is reduced in the toothing area of the shaft, preferably by means of an insulation air chamber or other insulated section, with respect to the heat flow in other shaft areas to be cooled.

Abstract: A gear pump comprising a housing for housing gear pump rotors in a housing interior, said housing having a housing end at an end face side of the housing through which at least one pump rotor shaft is guided from the housing interior to outside the housing, a shaft bearing in the housing end for rotatably supporting the rotor shaft, and a labyrinth seal in the housing end which in use surrounds the rotor shaft, wherein the shaft bearing is arranged separately from the labyrinth seal at a position spaced axially inward toward the housing interior with respect to the labyrinth seal.

Abstract: Method and apparatus for on-site cleaning of a gear pump by coupling the gear pump outlet to the gear pump inlet and to the inlet end of the passage and which bypasses the bearing and is preferably controlled by a valve element which can block off the bypass in normal operation and be opened for a cleaning operation to increase the pressure on the side of the bearing connected to the inlet and thereby increase the velocity of the flushing stream.