Abstract: The invention concerns a pump for conveying hot media wherein the pump has a pump housing, a seal housing (13, 14) disposed at a distance from the pump housing and is connected thereto, a bearing housing (19) connected to the pump housing via a Chinese lantern-shaped structure (7, 17, 18) and is disposed at a spacing from the seal housing, a fan wheel (22) disposed in the spacing, and a shaft (4) which penetrates the aforementioned parts. The delivery direction of the fan wheel extends from the connection between the pump housing and the seal housing (13, 14) towards the bearing housing (19) to enhance the cooling of the seal housing (13, 14) and of the bearing housing (19). To further enhance the thermal cooling properties, the drive motor is screed from the heated air flow by the bearing housing (19) and by a heat-insulating device (10) on the pump housing.

Abstract: A device is proposed for centering a bearing bushing on a shaft wherein the bushing is made of a material, such as a ceramic, that is sensitive to tensile stress. At lower operating temperatures the bushing exhibits a degree of play relative to the shaft, but is play-free relative thereto at high operational temperatures. Correct centering of the bushing is ensured even in the higher temperature range by the provision of a pair of centering rings which are connected to the shaft without play and act on the bushing to center it. The centering rings are made of a material which, in comparison to the bushing, is not sensitive to tensile stress. It is expedient to provide the two centering rings at the end faces of the bushing. The clamping action of the centering rings on the bushing assures rotational pull of the bushing at low operating temperatures.

Abstract: Centrifugal pump of the sectional-casing design, in which the casing sections (8, 9) each have a cylindrical casing shell and inner-wall parts (12-15) connected thereto in one piece. The casing shell of at least one casing section (8, 9) is composed of an outer, continuous shell part (24, 25) and of at least two separate inner shell parts (19-22) with respective associated inner-wall parts (12-15). The outer and the inner shell parts are expediently connected firmly to one another, especially by shrink bonding.

Abstract: Centrifugal pump for the delivery of hot media, in particular of hot water with at least one shaft passage through the pump housing (1,2) to the outside, which passage is provided with a mechanical seal (5). The sealing space is separated from the pump housing by a spacer zone (8) with close shaft play. For the avoidance of sealing disturbances by accumulated gas, the sealing space contains first means (12, 20, 21) for the generation of a liquid circulation in the sealing space with intensive impingement of the sliding surface area of the mechanical seal, second means (12, 18,21) for the stabilization of the liquid circulation away from the mechanical seal and thirdly a large-volume, flow-stabilized, ventable receiving space for separated gas. The gas fractions are thereby reliably isolated from the mechanical seal, separated from the liquid circulation and accumulate in the upper region of the sealing space, so that they are extracted from the liquid circulation and can be drawn off.