Valve

The invention relates to an automatic valve, in particular for gas compressors, with at least one sealing element, essentially designed as a mushroom-shaped piston, which is guided in the stroke direction with a guide attachment relative to a catcher plate and biased with a closing head by means of a spring against an opening sealed in the opposite seat plate is.

Such valves are also referred to as poppet valves and are known, for example, from US Pat. No. 2,624,587. The individual valves or individual sealing elements arranged in groups enable good efficiency and a long service life as well as simple spare parts storage, maintenance and assembly with the appropriate valve lift. The suspension, guide and

The closing force of the individual sealing elements is introduced via holes in the catcher plate. Constructions of this type have proven themselves especially in slow-running reciprocating compressors with a low compression ratio, as it is only in this compressor class that it is easily possible to achieve the large valve lift required for this type of valve, which ensures good efficiency. Problems arise especially with faster running compressors because the

Service life of the individual sealing elements is negatively affected due to the high opening and closing speeds.

Due to the lower manufacturing costs - compared to ring or plate valves - and also due to the simplified stock of spare parts, there has long been a need to use such poppet valves in other compressor classes, but always

Difficulties arise with the large valve lifts required for an efficiently working valve of this type or the large opening and closing speeds associated therewith. Furthermore, because of the required guide length of the sealing elements at the lifting height, the catcher plate must be made very thick, which leads to an undesirable increase in manufacturing costs, especially of the catcher plate, which from the point of view of mechanical stress is only a fraction of the thickness required for receiving, guiding and springing the sealing elements would need.

The problems mentioned are partially solved in an arrangement known, for example, from US Pat

Catcher plate is independent. The reliable fastening of this guide pin in the catcher, however, requires increased care during manufacture and assembly.

The object of the present invention is to improve a valve construction of the type mentioned so that the mentioned disadvantages of the mentioned known constructions are avoided and that in particular a simple and inexpensive construction, manufacture and assembly, as well as use in previously closed application areas of such valve types becomes possible.

This is achieved according to the present invention in a valve of the type mentioned in that the guide extension of the or each sealing element together with the spring is arranged and supported in a cup-like suspension element inserted in a through hole in the catcher plate and at least partially directly on the inner circumference with its outer circumference of the suspension element is performed. In this way, a single cup-like suspension element with any length of guide can be inserted in a - compared to the lifting height of the sealing elements - thin catcher plate per individual sealing element in a simple manner and also secured in a supported manner, which enables a light and material-saving construction. It can thus be realized in a very simple and inexpensive manner within wide limits guided stroke lengths of the sealing elements of any size, the modular structure ensuring simple assembly and maintenance as well as stocking of spare parts.

According to a particularly preferred embodiment of the invention it is provided that in order to limit the stroke of the sealing element, its guide attachment at its end remote from the closing head interacts with a stop on the bottom of the suspension element. Over the length of the cup-like suspension element between its holder in the catcher plate and the stop, the opening closing element on the catcher has an elastic stop to a certain extent, which reduces the stress on the components and increases the service life - especially of course for hanging elements made of plastic or similar elastic materials.

AT 412 302 Β

In a preferred embodiment of the invention, the suspension element can be inserted into the catcher plate from the side of the seat plate and fixed to the latter by means of a fastening element which is preferably designed as a snap or screw construction. This ensures on the one hand that the cup-like suspension element cannot fall out of the catcher plate and lead to malfunctions even when the fastening is loosened, while on the other hand simple exchangeability remains ensured.

In a further preferred embodiment of the invention, the suspension element and / or the sealing element can be made of impact-resistant plastic, preferably glass or carbon fiber reinforced PA (polyamide), PEEK (polyetheretherketone), PPS (polypheneline sulfide) or partially aromatic

PA (polyamides), optionally with additives that improve the sliding properties, such as in particular MoS2, PTFE (polytetrafluoroethylene), PFA (polyfluoroalkoxy) or graphite, and are preferably manufactured by injection molding. This enables robust and inexpensive designs of the wearing parts and thus opens up further applications.

According to a particularly preferred further embodiment of the invention, the spring biasing the sealing element can be made in one piece with the suspension element or the sealing element, which allows a simple anti-twist device to reduce abrasion problems and also to reduce assembly costs.

The invention is explained in more detail below with reference to the exemplary embodiments shown schematically in the drawing. 1 shows a perspective exploded view of a valve according to the invention and FIG. 2 shows a cross section through another embodiment.

The two valves shown can be used, for example, as suction or pressure valves of a reciprocating piston compressor for gases. There are in each case a plurality of sealing elements 1 designed essentially as mushroom-shaped pistons, which are provided with an in the w guided in the stroke direction essentially hollow-cylindrical guide extension 2 relative to a catcher plate 3 and each separately with a closing head 4 by means of a spring 5 against one in the opposite seat plate 6 sealed opening 7 are biased. In order to be able to make the guided length of the sealing elements 1 and thus the achievable lifting height independent of the thickness of the catcher plate 3, the guide extension 2 of each sealing element 1 together with the spring 5 is arranged in a cup-like suspension element 8 inserted in a through hole 15 of the catcher plate 3 and with its outer circumference is guided directly on the inner circumference of the suspension element 8. The interior 9 between the sealing element 1 and the suspension element 8, which accommodates the spring 5, is vented via a bore 10 in the base 11 of the suspension element 8.

The suspension element 8 is inserted into the catcher plate 3 from the side of the seat plate 6 and is fixed to the catcher plate 3 by means of a fastening element which is not shown in detail here, for example a snap or screw construction, which facilitates manufacture, assembly and maintenance.

The suspension element and possibly also the sealing element 1 itself can be made of plastic, for example glass or carbon fiber reinforced PA, PEEK, PPS or partially aromatic PA, optionally with additives that improve the sliding properties, such as MoS2, PTFE, PFA or graphite, and are preferably manufactured by injection molding be. The possibility of injecting the spring 5 in one piece with either the suspension element 8 or the sealing element 1 is particularly advantageous, since this results in a further simplification of storage, assembly and maintenance and, in addition, the stress on the

Contact points of the respective items is reduced by rotating the elements.

Furthermore, reference should be made here to a spacer ring 12 shown in both figures, which is fixed by means of several pins 13 opposite the catcher plate 3 and above its height an adjustment of the overall height of the valve can be made, so that this construction is also very easy as a replacement for existing ones such valves with predetermined

Total heights can be used. For the sake of completeness, reference should also be made to a dowel pin 14, which defines the position between the seat plate 6 and the catcher plate 3.

The arrangement of the sealing element 1 with the closing head 4 overlapping the cup-shaped suspension element 8, which can be seen especially in FIG. The relatively large guide diameter results in a very

AT 412 302 Β stable guidance of the sealing elements 1 even with large strokes. The bore 10 as a pressure relief of the interior 9 is not directed directly into the gas flow, which effectively prevents contamination of the interior 9.

If - as in Fig. 2 shown - the distance 17 between the underside of the closing head 4 and 5 upper edge of the cup-like suspension element 8 used is greater than the distance 18 between the lower end of the closing element 2 facing away from the closing head 4 and the stop 16 on the bottom 11 of the suspension element 8 results from the Length of the suspension element 8 has a certain elasticity, which reduces the stress when the closing element strikes and thus increases the service life of the parts.