Abstract: A sealing system for an essentially vertical shaft includes an active sealing element disposed between a first structural part rotating with the shaft and a second structural part stationary on a housing. A wall of the housing separates an upper oil-free volume from a lower volume containing oil. The oil flows through the sealing system through a gap formed by the first structural part and a third structural part stationary on the housing. The active sealing element is preferably a threaded shaft seal. In another embodiment, the active sealing element is a combination of a primary contact seal and a threaded shaft seal. The oil flow removes heat generated by the rotating system.

Abstract: In order to return the fluid which has penetrated into the sealing gap of a floating ring seal, recesses with closed edges are machined inside the region permanently covered by the sealing surfaces in a sealing ring in which the fluid is drawn to an end of the recess very close to the chamber to be sealed and hydrodynamically taken to a high pressure. Mirror-image recesses are effective regardless of the direction of rotation. The recesses are machined in very small sliding surfaces of ceramic sealing rings using a laser beam. Such a floating ring seal has a relatively low leakage rate with low friction. Two fluids can be mutually sealed with a double recess array.

Abstract: In the case of conventional seal arrangements comprising a sealing ring (5) consisting of a tough-elastic plastic material and a rubber-elastic stressing ring (6), where one edge (53) of the sealing ring (5) is in contact with the circumference of a rod (1), the pressing force encountered at the edge is dependent, to a very high degree, on the fluid pressure because the fluid pressure acts upon the circumferential surface of the sealing ring (5) either directly or via the rubber-elastic stressing ring (6). The pressing force, which consequently rises considerably in the presence of high fluid pressure, leads to high frictional forces at the sealing edge (53), which increase even further in the course of operating time.

Abstract: A sealing ring structure comprises a sealing ring provided with sealing edges which are arranged adjacent its ends and are in contact with a second machine part, and a stressing ring embracing the sealing ring, loading it in the radial direction and being fitted into an annular recess in the sealing ring. The tightness of such a structure at high fluid pressures is improved by the fact that the stressing ring is accommodated in a trapezoidal annular groove in the sealing ring which communicates with the space between the sealing edges by radial bores. The stressing ring, which is fixed in the groove of the sealing ring, is shifted in operation in response to the prevailing pressures whereby the sealing edge on the high-pressure side is relieved from pressure while the contact pressure exerted upon the sealing edge on the low-pressure side is simultaneously increased.

Abstract: A seal comprised of a sealing ring (1) and a clamping ring (2) presses against the end face (3 ) of a machine part (3). The sealing ring surrounds a tubular part (12), close to the low-pressure end of which are formed a narrow sealing ridge (131) and a support part (11). The axial thrust exerted on the sealing ring (1) is transferred essentially by the support part (11) via the elastomer clamping ring (2) to the end face (31), so that the sealing ring (11) can yield in a floating manner against radial movements of the opposite operating surface. The pressure to be sealed off acts both via the clamping ring (2) on the one side and, an annular groove (422) on the other side of the tubular part (12), so that the sealing surface is essentially relieved of its load.

Abstract: Means for preventing relative twisting between a seal ring and the parts of structure accommodating it by providing that in connection with high pressure shaft seals, the axial thrust resulting from the action of the pressure of the seal ring on its low pressure side radial face is taken up by a number of projections, the cross section of the seal ring undergoing undulating deformation as seen in the circumferential direction owing to the axial flexure of individual parts of the seal ring; it is furthermore possible to have additional projections as means for preventing twisting. As a consequence of the undulation of the entire cross section of the seal ring there will also be the useful effect of undulation of the seal interface edge, constituted by parts of this cross section, on the high pressure side.

Abstract: An arrangement for sealing that point at which the axially movable rod of a hydraulic device passes through its housing wall, comprises a sealing ring consisting of a tough-elastic plastic material or a harder elastomeric material and a stressing ring consisting of a softer elastomeric material, the two rings being accommodated jointly in a groove in the housing wall in such a manner that the sealing ring projecting from the groove is in contact with the axially moving rod, while the stressing ring seals the sealing ring against the circumferential face of the groove. The sealing ring is provided, on its inner surface facing the rod, with two axially offset annular sealing edges. The annular space between these two sealing edges is connected with the outer surface of the sealing ring by a channel. The channel opens at a point where it is covered by the stressing ring and which is located near the high-pressure end of the common contact face of the sealing ring and the stressing ring.

Abstract: In packings for hydraulic pistons or piston rods with a packing ring comprised of a tough elastic synthetic material as the contact packing between a stationary machine part comprising an annular groove and a moving machine part comprising an initial slope and of a rubber clamping ring clamping the packing ring radially and providing a sealing action with respect to the annular groove in the stationary machine part, an annular surface is located between the end face of a step at the high pressure side and a conical surface adjoining the latter on the low pressure side, which annular surface forms an obtuse angle with the conical surface of such a value that when the packing travels in over the initial slope the resultant F.sub.res of the normal force F.sub.N and of the frictional force F.sub.R halves the sealing edge angle. When using conventional materials and conventional angles for the conical surface and the inlet slope, a value of 45.degree.