Maag Gear-wheel & Machine Company Limited

Maag Pump Systems Ag

Eduard Mischler

Meinrad Donner

Roger Stehr

Fritz Haupt

Stefan Kalt

Alfred K Hunziker

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.

Gear pump and its uses

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.

Gear pump

The protective cutoff device includes a cutoff control and a cutoff valve system connected to an automatic position control which is present anyway in the gear wheel grinding machine serving for topological flank correction grinding and to an adjusting cylinder, respectively. As a result, the grinding wheel is effectively disengaged from the tooth flank in the process of being ground in the event of electric power failure and/or pressure failure or an undesirable pressure drop or upon the occurrence of any other disturbance or malfunction of the grinding wheel. Therefore one side of the adjusting cylinder is connected to a return line and the grinding wheel carrier or support is displaced against a stationary stop by a force or pressure accumulator.

Protective cutoff device for a gear wheel grinding machine

A correction device for the rolling tape tension on a gear grinding machine, especially a form grinding machine for spur and helical cylindrical gears, comprising tapes subjected to an initial basic tension at rest, the tapes being attached at one end to a rolling block, and there occurring between the rolling block and the tapes a relative rolling action. The tapes are attached at their other end to a tape stand which is movable to-and-fro. At the tape stand intermediate pieces or tape clamps are mounted on a device which imparts an additional torque on the rolling block. A gauging device measures the tension in the rolling tapes and compares it with the initial tension of the system at rest. In the event of a decrease in the tape tension relative to the initial tension on one side of the rolling block such gauging device actuates the device which produces an additional torque on the opposite side of the rolling block until the gauged tension on the one side of the rolling block again attains the level of the initial tension.

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Regensdorf, Switzerland

Eduard Mischler