Abstract: A receiver unit for a data transmission system, where transmitted data signals are accompanied by overhead signals, comprises processor means with one or more processors for processing said overhead signals as well as RAM type storage means, in which the processor means can store the data which are obtained by the processing of the overhead signals. Further, between the arriving overhead signals and the processor means there is a buffer circuit, in which the overhead signals can be temporarily placed prior to their processing, and from which the processor means can fetch the signals as the processor means become ready to process the signals.

Abstract: A gear pump which is fitted with a magnetic coupling (6) to ensure against leaks uses circulation of the pump fluid to cool the magnetic coupling. The circulation is established by supplying the pump rotor (4) with radial channels (24) which terminate in recesses on the periphery of the rotor and which are connected to an axial channel (26) in the rotor shaft leading to the end of the shaft which is nearest the magnetic coupling. The fluid which is drawn through the channels (24) is mixed with the main stream of fluid in a section which is cut out of the wall of the pump chamber (16), and fresh cooling fluid is drawn via the chamber (40) to the radial gap in the magnetic coupling.