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EP-3956589-B1 - SEALING SYSTEM FOR SWITCHABLE WATER VALVES

EP3956589B1EP 3956589 B1EP3956589 B1EP 3956589B1EP-3956589-B1

Inventors

  • KURTZ, ANDREAS
  • HOWACK, GERD
  • PILZ, HENRY

Dates

Publication Date
20260513
Application Date
20200623

Claims (14)

  1. A sealing system for switchable water valves, having a valve actuating rod (3), a cartridge (6), a linear stepper motor (7), and a valve body (17), the sealing system comprising a drive by means of the linear stepper motor (7) disposed at the cartridge (6) and adjustment by means of the valve actuating rod (3) and a sealing body (5) disposed in the valve body (17), the sealing body (5) comprising a sealing body main part (2) with at least one central rib (12) is disposed on the valve actuating rod (3), two sealing rings (1) spaced a defined distance from each other are press-fitted on the sealing body main part (2), and one or more axial flow bypasses (21) are disposed as recesses in the sealing body main part (2) underneath said sealing rings (1) or in the sealing rings (1) themselves; characterized in that the two sealing rings (1) are fixed in their positions by two circumferential indented or continuous flange ribs (15) formed at each outer end on the sealing body main part (2) and are secured against slipping on the surface of the sealing body main part (2) wherein an indented or continuous rib (23) is disposed on a main body shank (22) at or immediately proximate to the area of the central rib or ribs (12) for spacing the sealing rings (1) from the sealing surfaces of the central rib or ribs (12)
  2. The sealing system for switchable water valves according to claim 1, characterized in that said one or more axial flow bypasses comprise three or more axial flow bypasses (21) disposed as recesses in the sealing body main part (2) in the area of the sealing rings (1).
  3. The sealing system for switchable water valves according to claim 1 or 2, characterized in that a reducing ring (24) is formed and disposed on the flange ribs (15) of the sealing body main part (2) axially outwardly on one or both sides in the direction of the sealing areas of the valve body (17).
  4. The sealing system for switchable water valves according to claim 3, characterized in that a reducing ring flange or cone is formed and disposed on the reducing ring (24) axially outwardly towards the sealing areas of the valve body (17).
  5. The sealing system for switchable water valves according to any of the claims 1 to 4, characterized in that, when viewed in cross-section, the axial flow bypasses (21) are designed to be half open or open, or individual ones are designed half open and the others open or are designed half open and open in alternation.
  6. The sealing system for switchable water valves according to any of the claims 1 to 5, characterized in that in the case of two central ribs (12), a central recess (14) is formed in the sealing body main part (2) between the two central ribs (12).
  7. The sealing system for switchable water valves according to any of the claims 1 to 6, characterized in that the sealing body main part (2) with the central ribs (12) is formed as a one-piece injection moulded plastic part.
  8. The sealing system for switchable water valves according to any of the claims 1 to 6, characterized in that the sealing body main part (2) with the central ribs (12) is formed in multiple parts.
  9. The sealing system for switchable water valves according to any of the claims 1 to 8, characterized in that one, two or more cavities (18) are formed inside the sealing body main part (2).
  10. The sealing system for switchable water valves according to any of the claims 1 to 9, characterized in that the sealing rings (1) are inserted in the sealing body main part (2) under a defined pre-tension by the inner diameter of the sealing rings (1) being somewhat smaller than the outer diameter of the sealing body main part (2) in the area of the valve seat .
  11. The sealing system for switchable water valves according to any of the claims 1 to 10, characterized in that the sealing body main part (2) is coupled with the valve actuating rod (3) at a coupling point (9), which is designed as a solid body joint or a ball-and-socket joint.
  12. The sealing system for switchable water valves according to any of the claims 1 to 11, characterized in that the contours of the sealing rings (1) of the O-ring type are configured and shaped to match the contours of the sealing areas (10) of the valve body (17) of a two-way or three-way water valve (11).
  13. The sealing system for switchable water valves according to any of the claims 1 to 11, characterized in that the contours of the two sealing areas (10) of the valve body (17) of a two-way or three-way water valve (11) are configured differently.
  14. The sealing system for switchable water valves according to any of the claims 1 to 13, characterized in that a cavity (4) is formed at the back of the sealing rings (1) between a rear sealing surface (8) of the sealing rings (1) and the central rib or ribs (12).

Description

The invention relates to an optimized low-noise sealing system for switchable water valves for use in heating appliances and water heaters, in particular for two-way or three-way water valves. In domestic heating appliances or water heaters, in particular in the field of gas-fuelled boilers, a variety of different valve types are known which interrupt and, as needed, redirect the water flow for water circuits. Generally, the valves are fully open or fully closed. Preferably, electromechanically actuated two-way valves or three-way valves are used here. These valves must be designed such that inside them there is no significant pressure drop during water flow and leakage can be reliably excluded in the valve area within the water circuits over the whole temperature range in which they are operated. To be able to avoid leakage, elastically deformable materials are used as sealing bodies, on which a specific pressure force must then be exerted so that the material can be deformed within specific limits in order to ensure the required tightness over extended periods despite multiple switching cycles. On the other hand, the forces acting on the valve body should not be too large because this involves high energy consumption. The electromechanical drives should thus not be dimensioned too large to be able to use cost-efficient drives. Since these are mass products, even small savings result in big economic effects. In principle, there are two solution approaches. On the one hand, there are valves with a hollow cylindrical valve closure system or with spherical valve spaces and matching spherical valve bodies for sealing the valve. At the moment of sealing, a pressure surge occurs in the valve, causing a loud noise which in turn is transmitted through the connected piping system and considered as disturbing. A mixing valve according to the three-way principle with a cylindrical valve closure, which is guided in a bush in a linearly moveable manner, is known from DE 20 2011 004 433 U1. In this valve, the cylindrical valve body is disposed in a mixing chamber such that it shuts off or opens variable proportions of the cross-section of two inlet pipes. Here, the valve spool is made of stainless steel and the valve body is guided in a bush of a carbon-graphite material in a form-fitting manner. This design is costly and is difficult to be manufactured automatically in large series because what matters here are the precise fit of the individual valve components relative to each other and the precise seating of the valve spool. DE 697 18 317 T2 describes a somewhat more spherical sealing body, which is supposed to offer an improved valve arrangement for heating systems and water heaters with greater leak-proof capacity. The sealing body described here is a kind of sealing ball of a cylindrical metal body, which in turn must be moved into cylindrical sealing surfaces. To prevent leakage, a side ring (acting as the actual sealing ring) is disposed inside the valve body to be compressed radially in order to ensure tightness. This design is also intended to avoid any contamination or deposits inside the valve body or to ensure that these have no influence on the tightness of the valve. The disadvantage of this solution is a relatively long travel path for the sealing body because it must be displaced quite a long way into the cylindrical sealing surfaces of the valve seats and as far until the central side ring (sealing ring) can produce its effect. Furthermore, this solution is characterized by the use of expensive materials and the relatively complex manufacture of the sealing body, i.e. manufacture is hard to automate. An electromechanically operated three-way valve with two valve seats is known from DE 10 2012 219 745 A1, wherein a single valve seal is disposed to be moved towards a valve seat with a minimal area to seal it appropriately. The sealing surfaces of the valve body are tapered such that the sealing body lies flat against them. The valve stem closing element is smaller in diameter than the mean inner diameter of the valve body portion. This has the advantage that only the areas lying against the valve surfaces are stressed. The sealing body is guided axially at two opposite points inside the valve body so that it cannot cant or lie against the engaged valve seat in an off-centre position, i.e. in a slantwise manner. This, however, increases the flow resistance to the flowing fluid. It is also disadvantageous that any deformations of the sealing body, e.g. when the sealing body has been pressed on one side against one of the valve seats for a very long time, can potentially affect leakage in the sealing position in the other position. EP2184520A2 discloses a valve. The valve has a piston-shaped valve control element which is moved in an axial direction between a closed position and an opened position, in order to lock or to open the flow between the two channels. The valve control element has an inner passage