Abstract: A water pump, especially for the cooling system of a combustion engine of a car, has a housing with a space for a fluid. This space contains a pump device. The pump device is mounted on a shaft which projects form the housing. The shaft rotates while being supported by a bearing assembly. The bearing assembly has an outer stationary ring mounted on the housing. The fluid space id sealed with respect to the shaft by a sealing unit having a first ring connected to the shaft, and a stationary second ring mounted on the outer ring of the bearing assembly. The first and second rings have sealing surfaces which are directed toward one another, or extend axially. The first ring is resiliently biased toward the second ring, to provide a seal therebetween. The first ring is connected to the shaft via an elastic dampening and centering element located between the inner circumference of the first ring and the outer circumference of the shaft, and distributed over the circumference of the shaft.

Abstract: A sealing assembly forming a seal using a magnetic liquid around a rotatable shaft, comprising an armature for conducting a magnetic field, the armature having a free end adjacent the shaft to form an annular sealing gap; a quantitiy of magnetic liquid contained in the sealing gap by the magnetic field; and at least one covering member mounted on the assembly on one side of the gap to cooperatively define a space with the shaft for containing an amount of fluid at least two times the volume of the gap.

Abstract: A device for holding an amount of magnetic fluid by means of a magnetic field inside a gap-shaped space located around a rotatable shaft, including a unit consisting of an annular pole piece whose inner circumferential plane is located at a relatively short distance from the shaft. The device has at least one annular permanent magnet for generating the magnetic field, whereby the magnetic fluid is kept inside the gap-shaped space between this unit and the shaft. The invention is characterized by the fact that the pole piece (3, 14) is located between two annular permanent magnets (1, 2; 12, 13), whereby the analogous poles of these magnets are directed at each other and the inner circumferential planes of the two magnets are located essential equidistance from the shaft (4, 11) in order to form, together with the shaft, two annular spaces which are located on both sides of an annular intermediate gap.