The invention relates to a seal arrangement for a liquid-tight connection between a connection opening of a liquid-conducting component, especially of a washing container of a dishwasher, and a connection piece of a liquid flow device, especially a recirculation pump, as well as to a method for manufacturing such a seal arrangement.
In household appliances, especially in dishwashers, water-conducting units are often connected to the washer container by means of liquid-tight sealing elements.
In a dishwasher for example a seal arrangement can typically be connected between a pressure piece of a recirculation pump and an inlet connection of a washing container or a pump sump. The seal arrangement can consist of a hose-like sealing element made of soft rubber material which is pushed onto both the inlet connection of the washing container and also onto the pressure piece of the recirculation pump. The hose-like sealing element is thus in sealing contact with the inlet connection of the washing container and the pressure piece of the recirculation pump respectively.
In the area of the sealing points between the sealing element and the inlet or pressure piece the sealing element is strengthened with outer ring sleeves which can be embodied from a dimensionally-stable plastic material rigid by comparison with the rubber material. In this way a predetermined compression force is applied to the soft rubber material in the sealing points.
During dishwashing overpressure is applied to the interior space of the washing container or the pump sump, which acts on the sealing element with a pushing force against the installation direction. For stable retention the sealing element is thus gripped by attachment clamps in the area of its sealing points. The seal arrangement can thus have a number of separate components which can only be installed with some effort.
It is an object of the invention to provide a seal arrangement or a method for manufacturing such a seal arrangement in which the number of components can be reduced and which is also easy to install.
The object is achieved by the features and preferred developments of the invention as disclosed in the claims.
The sealing element has a radial inner sealing point and also a radial outer sealing point. The radial outer sealing point of the sealing element is in sealing contact with the edge of a connection opening of a liquid-conducting component, such as a dishwasher washing container. The sealing element is also in sealing contact with its radially inner sealing point with the inside connection piece of a liquid flow device, such as a recirculation pump for example. In this way the sealing element, in terms of installation, can be easily pressed into the ring gap between the connection opening edge and also the connection piece. Additional clamps are not required in this case.
For a reliable seal the edge of the connection opening can be delimited by an approximately cylindrical ring wall. The ring wall can be in sealing contact over a large surface area with the outer sealing point of the sealing element.
As already mentioned above, the sealing element can be made of a soft rubber material. To increase its dimensional stability the sealing element can feature additional support elements, especially retaining rings or ring sleeves, with the aid of which the sealing element can be pressed in the area of its sealing points against the edge of the connection opening or against the connection piece respectively.
The two sealing points of the sealing element can be connected to each other by an equalization section, especially by a bellows section. The bellows section can especially be embodied in the form of a corrugated section. It can compensate for installation-related tolerances. In addition the bellows section can reduce transmission of vibrations between the liquid flow unit, such as the recirculation pump, and the water-conducting component, such as the washing container.
For simple and precisely-positioned assembly of the sealing element the edge of the connection opening and/or the connection piece can be embodied with a movement stop, especially a ring stop, against which the sealing element can be pressed.
Preferably the sealing element with its two sealing points can be pushed in a common assembly direction onto the edge of the connection opening and onto the connection piece until both sealing points are stopped by the above-mentioned movement stops.
For a smooth assembly movement the connection piece is pre-positioned exactly in relation to the connection opening in a pre-assembly step. In this case the connection piece can project in a first variation at least partly into the connection opening of the water-conducting component. Depending on the situation with regard to installation space, the connection piece can also be arranged offset in height at a distance outside the water-conducting component. The sealing element can be adapted to both installation positions with the above-mentioned equalization section.
In the event of the sealing element being pushed into a ring gap between the connection opening edge and the connection piece, starting from an interior space, in the installation position the sealing element is exposed to the interior of the water-conducting component. Where a washing container is used as the water-conducting component its interior is pressurized during dishwashing. The liquid column in the interior thus presses with excess pressure on the exposed sealing surfaces of the sealing element.
Unlike in the prior art, in accordance with the invention no pushing force is created which promotes the working loose of the sealing element from the connection opening or from the connection piece. Instead, in accordance with the invention, the sealing element is pressed in the area of its sealing points against the two movement stops as well as against the edge of the connection opening, which causes the sealing between the connection piece and the connection opening edge to be strengthened even further.
The invention also relates to a dishwasher having at least one inventive seal arrangement.
Other advantageous developments of the invention are described in the subclaims.
The invention and its embodiments and developments and their advantages will be explained in greater detail below with reference to drawings, in which the respective drawings show the following schematic diagrams:
In accordance with
As can be seen from
On its opposite side the sealing element 18 is in sealing contact with its radially outer side 27 with a cylindrical ring wall 29 which delimits the opening edge of the connection opening 21 in the container floor 13.
To stabilize the sealing points 25, 27, rigid ring collars 31, 33 are integrated into the rubber material 23 of the sealing element 18. The internal diameter of the lower ring collar 31 in the installed position is dimensioned so that the sealing point 25 is pressed with a predetermined compression in the radial direction against the pressure piece 16 of the recirculation pump 16. Correspondingly the outer diameter of the upper ring collar 33 in the installation position is dimensioned so that the radially outer sealing point 27 is likewise pressed with a suitable compression in the radial direction against the ring wall 29 of the connection opening 21.
As can further be seen from
As an alternative to the exemplary embodiment shown, the recirculation pump 17 with its pressure piece 16 can also be in direct connection with the pump sump 15 of the dishwasher in flow terms. In this case the connection opening 21 is not formed directly in the dishwasher floor 13 but is embodied directly in the pump sump 15.
During dishwashing the recirculation pump 17 displaces washing liquor in the flow directions I, II, III shown in the diagram in the direction of the spray arms 7, 9. In the liquid space 39 upstream between the recirculation pump 17 and the connection opening 21 of the washing container 13, an overpressure p1 therefore obtains by comparison with the ambient pressure p0.
The surfaces 41 of the sealing element 18 exposed to the liquid space 39 thus have a pressure force applied to them from within. The forces FR produced as a result, in accordance with
The installation of the sealing element 18 between the connection opening 21 of the washing compartment floor 13 and the pressure piece 16 of the recirculation pump 17 is illustrated with reference to
In a subsequent installation step the sealing element 18 is pressed with a second joining movement in a vertical installation direction B with the aid of an installation stamp 43 into the ring gap 19 between the ring wall 29 and the pressure piece 16. In this case in a joint operation the two sealing points 25, 27 of the sealing element 18 are pressed into sealing contact with the ring wall 29 of the connection opening 21 as well as with the pressure piece 16 of the recirculation pump 17. The installation stamp 43 is provided with correspondingly graduated pressure surfaces in order to make possible the offset installation position of the sealing points 25, 27 offset in accordance with
The two sealing points 25, 27 of the sealing element 18 are connected to each other via a bellows section 45 which makes possible such an installation-related offset between the two ring collars 31, 33 in the installation direction B. During dishwashing the bellows section 45 additionally acts as an insulation element, with which a transmission of operation-related vibrations from the recirculation pump 17 to the washing container 13 is reduced.
In
In this way an advantageous seal arrangement is provided for a dishwasher which especially seals from the pressure or wet area of the pump sump to the recirculation pump and/or other units, preferably without further clips or securing devices.
Number | Date | Country | Kind |
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10 2010 031 559.1 | Jul 2010 | DE | national |