EP0346285B1 - Valve arrangement - Google Patents

Description

The invention relates to a valve arrangement, in particular for piston compressors, pumps or the like, with a component which contains a passage opening through which a fluid can flow and a disk-like valve body which covers the passage opening and interacts with a valve seat surrounding it and which, together with a valve seat which can be braced against it The spring element is freely movable in a fluid flow-through recess of a guide part that at least partially surrounds the valve seat, said recess being designed at a distance from the valve seat that allows the valve body to be lifted off, with inwardly projecting shoulders on which the Part of the spring element facing away from the valve body rests under pretension.

In a valve arrangement of the type mentioned known from FR-A-2 339 116, the valve body formed by a flat plate is braced against the valve seat by a coil spring. This valve construction requires a relatively large, high installation space to accommodate the coil spring.

There are also others, e.g. Valve arrangements used in reciprocating compressors are known, each having an annular or concentric slot valve plate, which together with a spring plate by a central screw or e.g. are clamped by three corresponding fastening elements distributed over the valve between a valve seat part which can be placed on the passage opening and a holding plate which can be braced against the latter, the valve seat part and the holding plate being provided with openings through which the fluid can flow. These known, multi-part valve constructions each require a relatively large installation space and, in addition, a relatively large amount of work when assembling and installing the valve.

The invention has for its object to provide a valve arrangement of the type mentioned improved in this regard in a simplified, compact and inexpensive construction, in particular with a low overall height, which enables an embodiment with a small clearance and correspondingly small dimensions of the required installation space.

This object is achieved according to the invention in that the valve body is designed with a central local elevation on the side facing away from the valve seat, and in that the spring element is formed by a round spring plate which can be loosely braced against this elevation, the elevation being a support surface for a central supporting surface the spring plate.

The inventive design of the valve body and the spring element enables a particularly flat, compact design of the valve, its installation height essentially only by the thicknesses of the valve body and the spring plate and is determined by the stroke of the valve body. At the same time, simple installation and removal of the spring element in particular is ensured, since the flat spring plate, when untensioned, is correspondingly easier to handle than a helical spring, for example.

Embodiments of the invention are specified in the dependent claims.

• Fig. 1 einen mit Ventilanordnungen nach der Erfindung versehenen Hubkolbenkompressor in einem durch zwei Horizontalebenen geführten Schnitt;
• Fig. 2 eine der Ventilanordnungen nach der Erfindung in einem Ausschnitt aus der Fig. 1 in einer grösseren Darstellung;
• Fig. 3 die Ventilanordnung nach Fig. 2 in einer Draufsicht;
• Fig. 4 eine Einzelheit der Ventilanordnung in einer Draufsicht.

Further features result from the following description of an exemplary embodiment of the invention shown schematically in the drawing. Show it:

• 1 shows a reciprocating compressor provided with valve arrangements according to the invention in a section taken through two horizontal planes;
• 2 shows one of the valve arrangements according to the invention in a detail from FIG. 1 in a larger representation;
• 3 shows the valve arrangement according to FIG. 2 in a top view;
• Fig. 4 shows a detail of the valve assembly in a plan view.

1 has four cylinders 1, 2, 3 and 4, in which pistons 5, 6, 7 and 8 are guided. The cylinders 1 and 2 have a common axis 10 lying in the plane of the drawing, while the cylinders 2 and 4 are arranged on a common axis 11 set back from the plane of the drawing. The pistons 5 and 7 are coupled via a yoke 14 connecting their piston rods 12 and 13 to a sliding piece 15 which is mounted on a crank pin 16 of a crankshaft 17. The crankshaft 17 is connected to a motor, not shown, for example an electric motor. The slider 15 is guided transversely to the axis 10 between two guideways 18 formed in the yoke 14. The pistons 6 and 7 are via a yoke 22 connecting their piston rods 20 and 21, respectively coupled to a second slider, not shown, mounted on the crank pin 16, which is displaceably guided transversely to the axis 11 in the yoke 22, which is offset by 90 ° relative to the yoke 14.

The pistons 5, 6, 7 and 8, which are guided in cylinder inserts 23, 24, 25 and 26, each define a compression space 31, 32, 33 in the cylinders 1, 2, 3 and 4 which are closed by detachably fastened cylinder covers 27, 28, 29 and 30 or 34. The compression space 31 of the cylinder 1 forming the first compression stage is delimited by an end plate 35 which is inserted into the cylinder head 27 and which is provided with several, for example four through openings 36 arranged offset in the circumferential direction are provided. The passage openings 36, of which only one is visible in FIG. 1, are each provided with a pressure valve 37. The pressure valves 37 are each arranged on the side of the end plate 35 facing away from the piston 5 in a recess 38 of a guide part, according to FIG. 1 of a holding plate 40, which is detachably fastened on the end plate 35. A plurality of passage openings 42 are also formed in the piston 5, each of which is provided with a suction valve 41. Correspondingly - during the suction stroke of the piston 5 and with the suction valves 41 open - a connection is established between the compression space 31 and a cylinder space 43 separated from it by the piston 5, which is connected to a feed line (not shown) for the medium to be compressed, e.g. Natural gas, is connected. The suction valves 41 are arranged on the side of the piston 5 facing the compression space 31, each in a recess 44 of a further guide part detachably fastened to the piston 5, as shown in the illustration of a holding plate 45.

In the cylinders 2 and 3, the compression spaces 32 and 33 are each one on the cylinder insert 24 and 25th attached end plate 46 and 47 limited. The end plates 46 and 47 each contain a central through-opening 36 provided with the pressure valve 37, for example four, provided with suction valves 41, circumferentially offset through-openings 42, of which only one is also visible in FIG. 1. The recess 38 receiving the pressure valve 37 is formed in the cylinder cover 28 and 29, respectively. The recesses 44 receiving the suction valves 41 are each formed in the end part of the cylinder insert 24 or 25 facing the inside of the end plate 46 or 47, which serves as a guide part for the suction valves 41. The recesses 38 are each connected to the compression space 32 or 33 by a lateral opening.

In the cylinder 4, both a passage opening 36 provided with the pressure valve 37 and a passage opening 42 provided with the suction valve 41 are formed in the cylinder cover 30, the recess 38 receiving the pressure valve 37 in a connecting nipple 50 which can be screwed into the cylinder cover 30 of a pressure line leading away from the compressor 51 is formed, while the recess 44 receiving the suction valve 41 is formed in a nipple 52 which connects the compression space 34 to a flow channel 58 formed in the cylinder cover 30.

1, the piston 5 is shown in its top dead center position, in which the compression space 31 is the smallest. During the suction stroke of the piston 5, the gas supplied to the cylinder space 43 is sucked through the passage opening 42 with the suction valve 41 open. During the pressure stroke, the gas compressed to a pressure of, for example, 5 bar, with the pressure valve 37 open, is passed through the passage opening 36 into a cylinder space 55 and from there via a connecting cylinder cover 27 and 28 Flow channel 56 and an annular channel 48 of the second compression stage formed by the cylinder 2 are supplied.

The gas sucked into the compression chamber 32 through the passage openings 42 during the suction stroke of the piston 6 is reduced to a pressure of e.g. Compressed 20 bar and supplied with the pressure valve 37 open via a flow channel 57 connecting the cylinder covers 28 and 29 and an annular channel 49 to the third compression stage formed by the cylinder 3.

In Fig. 1, the piston 7 of the cylinder 3 is shown in the bottom dead center position, in which the compression space 33 is largest. The gas sucked into the compression space 33 during the suction stroke of the piston 7 is reduced to a pressure of e.g. 60 bar compressed and fed via the flow channel 58 connecting the cylinder covers 29 and 30 and through connection channels 59 and 60 formed in the nipple 52 to the fourth compression stage formed by the cylinder 4.

The gas sucked into the compression space 34 during the suction stroke of the piston 8 is brought to a pressure of e.g. 180 bar compressed and supplied with the pressure valve 37 open via the pressure line 51 to a gas fuel tank, not shown, which e.g. can be designed as a fuel tank of a motor vehicle.

All pressure valves 37 and suction valves 41 are, apart from any different dimensions of the interacting parts, essentially the same design. According to the illustration in FIGS. 2, 3 and 4, which show the pressure valve 37 of the cylinder 1, the pressure valve 37 contains a disk-shaped round valve body 61 and which completely covers the associated passage opening 36 a round spring plate 62, under the action of which the valve body 61 loosely rests with a flat contact surface against a valve seat 63 surrounding the passage opening 36. As shown, the valve seat 63 is formed directly on the end plate 35 delimiting the compression space 31. The valve body 61 is provided on the side facing away from the valve seat 63 with a central elevation 64, which can be formed, for example, by a cylindrical extension or, as shown in FIG. 2, by a truncated cone-shaped thickening of the valve body 61. A bearing surface 65 for a central supporting surface 66 of the spring plate 62 is formed on the elevation 64. The spring plate 62 is held clamped in the recess 38 of the holding plate 40 surrounding the pressure valve 37 against the valve body 61, the recess 38 being designed with a shoulder 67 narrowing in cross section. The shoulder 67 protrudes at a distance from the valve body 61 which allows the valve body 61 to be lifted off and thus forms an abutment for the edge part 71 of the spring plate 62 which can be biased against it.

According to the representation in FIGS. 2 and 3, the recess 38 can be designed with local, niche-like extensions 68 which are distributed over its circumference and which ensure a low-loss flow through the recess 38 through the gas emerging from the compression space 31 when the pressure valve 37 is open. It goes without saying that a different number of extensions, or possibly only a single corresponding connection opening, can also be provided.

As can be seen in particular from FIG. 4, three slots 70 are formed in the spring plate 62 over their surface in the circumferential direction, each of which, one on an annular edge portion 71 the reference point 72 lying on the spring plate 62, runs spirally essentially over the four quadrants A, B, C and D of the surface of the spring plate 62 against its central support surface 66. This support surface 66, which corresponds to the contact surface 65 of the elevation 64, is determined by an imaginary circle inscribed between the inner ends 73 of the three slots 70. The slots 70 are designed such that, starting from their respective reference point 72, they each have an initial section E running along the edge section 71 with a width increasing in the area of the first quadrant A towards the second quadrant B and decreasing at the beginning of the second quadrant B. , and have a central section F running over the remainder of the second quadrant B and essentially over the third quadrant C with an essentially constant, small width and an end section G running in the area of the fourth quadrant D with a width increasing again towards the support surface 66 .

The course of the slots 71 is selected such that webs 74 remain between them, each of which has a width H which, starting from the edge part 71, continuously decreases slightly over the first half of its length and against the second half of its length the central support surface 66 continuously increases slightly. The support surface 66 can be made relatively small without an opening, and thus, like the corresponding contact surface 65 of the elevation 64. This construction therefore results, with optimal use of the material of the spring plate 62, in a design with relatively long, favorably stressed webs 74, which allow a relatively large spring travel with a small diameter of the spring plate 62. Accordingly, a maximum deflection of the spring plate is obtained if a minimum clearance is maintained 62 achieved so that the structural dimensions of the compressor can be kept correspondingly small.

The valve design according to the invention is particularly suitable for small, dry-running compressors, the valve body 61 and spring plates 62 e.g. Can have diameters of about 10 to 12 mm. The spring plates 62 can be made of spring steel or another material suitable for leaf springs, such as titanium or beryllium, and each have a thickness of 0.1 to 0.3 mm. It goes without saying that designs with dimensions other than those described are also possible. The valve bodies 61 can be made of metal or a plastic, e.g. Polyether ether ketone (PEEK). In connection with the spring plate 62 described above, the plastic design, in particular, enables a cost-effective, low-mass and low-noise valve arrangement to be achieved, which responds quickly and which guarantees operation with minimal wear and a correspondingly long service life. An optimal ratio between the maximum deflection and the spring force of the spring plate 62 can be achieved in versions in which the bearing surface 65 formed on the elevation 64 and the central support surface 66 of the spring plate 62 have a diameter which is approximately 1/4 to 1/8 of the diameter of the valve body 61.

Modified embodiments can contain valve bodies, each of which is designed with a conical or lenticular contact surface and which cooperate with correspondingly designed valve seats. An embodiment is also possible in which the valve seat is formed on an exchangeable insert.

The invention is not limited to use on compressors of the type described and illustrated above, but is also for other, single or multi-stage designs, as well as for other applications, e.g. suitable for pipes, breathing air compressors, compressors for low-temperature technology or compressors for compressing CO₂, nitrogen and similar media. The valve arrangement according to the invention is also suitable for use on pumps or lines for liquid media, e.g. Water or liquid gas, suitable.

Claims (10)

1. A valve arrangement, more particularly for reciprocating compressors, pumps or the like, comprising a component (5, 30, 35, 46, 47) having a passage (36, 42) through which a fluid can flow, and a discoid lid (61) which covers the passage (36, 42) and co-operates with a valve seat (63) extending around said passage and which, together with a resilient element urgeable against it, is disposed for free movement in a recess (38, 44) in a guide part extending around the valve seat (13) at least to some extent, said recess (38, 44) being adapted to have a fluid flow therethrough and being open towards the passage (36, 42), and being formed with inwardly projecting steps (67) at a distance from the valve seat (63) such as to permit lifting of the lid (61), that part (71) of the resilient element which is remote from the lid (67) bearing with prestressing against said steps (67), characterised in that the lid (61) has, on the side remote from the valve seat (63), a central local protuberance (64) and in that the resilient element is formed by a round diaphragm plate (62) urgeable loosely against said protuberance (64), the protuberance (64) having an abutment surface (65) for a central thrust surface (66) of the diaphragm (62).

2. A valve arrangement according to claim 1, characterised in that the valve seat (63) co-operating with the lid (61) is devised directly on the component (5, 30, 35, 46, 47) containing the passage (36, 42).

3. A valve arrangement according to claim 1 or 2, characterised in that the lid (61) is made of plastics, for example, polyether etherketone.

4. A valve arrangement according to any of the previous claims, characterised in that the protuberance (64) of the valve lid (61) is frustum-shaped and in that the abutment surface (65) facing the diaphragm (62) has a diameter of from ¼ to ⅛ of the valve lid diameter.

5. A valve arrargement according to any of the previous claims, characterised in that the diaphragm (62) is made of spring steel and is from 0.1 to 0.3 mm thick.

6. A valve arrangement according to any of the previous claims, characterised in that the diaphragm (62) is formed with three slots (70) and each slot, starting from a reference position (72) on the edge part (71), extends in a spiral substantially over the four quadrants (A, B, C, D) of the surface of the diaphragm (62) towards the central thrust surface (66), the thrust surface (66) which remains between the inner ends (73) of the slots (70) corresponding to the abutment surface (65) on the valve lid protuberance (64).

7. A valve arrangement according to claim 6, characterlsed in that each slot (70) has, starting from the reference position (72): an initial part (E) which extends substantially over a first quadrant (A) with a width increasing towards the second quadrant (B) and decreasing at the start thereof; a central part (F) which extends over the remainder of the second quadrant (B) and over the third quadrant (C) with a reduced and substantially constant width; and a terminal part (G) which extends over the fourth quadrant (D) with a width increasing towards the first quadrant (A).

8. A valve arrangement according to claim 6 or 7, characterised in that the slots (70) bound three webs (74) which extend from the edge part (71) towards the central thrust surface (66) and which, starting from the edge part (71), each have a width (H) decreasing continuously substantlally over the first half of web length and increasing continuously substantially over the second half of web length towards the central thrust surface (66).

9. A valve arrangement according to any of the previous claims, characterised in that the recess (38, 44) receiving the lid (61) and the diaphragm (67) has on its periphery at least one local widering (68) increasing its cross-section.

10. Use of a valve arrangement according to any of the previous claims in a reciprocating compressor for compressing gas, such as natural gas, to be stored as fuel in a motor vehicle.

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