Patent Application
20110147634
The invention relates to a ball valve, in particular for highly pressurized media, with a valve housing in which a ball spindle, which is pivoted around an axis in the housing at an axial distance from the pivot support, has a ball body as a blocking element between the input part and the output part of a passage of the housing for media, and the flow opening located in the ball body can be oriented to the passage for media for unblocking the ball valve by turning the ball spindle.
Ball valves of this type are known and are readily available in commerce, see for example the applicant's brochure D 5.501.19/06.03. These ball valves are used for blocking of volumetric flows preferably in hydraulic circuits, but also for gaseous and/or aggressive media. These valves are not used as throttle valves, but as controllable blocking elements which in the opened state form a full flow passage for unobstructed flow of a medium.
In the common use of these valves in systems with high system pressures, the supply connections between the valve housing and pipeline system must be made especially reliable and secure. At high pressure stages, for example in the range of 500 bar, therefore supply connections by welding or positive clamping are conventional. This does yield high operating reliability, but problems arise when replacement of the ball valve is necessary, for example, at the end of the service life of wearing parts, for example the ball spindle. In other words, for supply connections which cannot be easily disconnected, nondestructive dismounting is not possible.
With respect to this problem, the object of the invention is to provide a ball valve of the type under consideration which, if necessary, enables dismounting of the wearing parts from the valve housing without disconnecting the supply connections on the valve housing.
According to the invention this object is achieved by a ball valve which has features of claim 1 in its entirety.
In that, according to the characterizing part of claim 1, the ball spindle is supported on two end sections which are made identically and which are connected to the ball body on both sides, the support on at least one end section being formed by a support cover which has integrated slide bearing elements and which can be detachably mounted on the housing, nondestructive dismounting of the ball spindle and the pertinent wearing parts is possible such that at least one support cover on the end section of the ball spindle is removed and the flanges are detached. In this way, with motion which is axial with respect to the spindle axis, the ball spindle can be drawn out of the housing, the second end section being withdrawn from its slide support. The ball spindle therefore cannot be removed without the flanges being detached or removed.
In an especially advantageous manner the arrangement can be such that the support on the two end sections is formed by support covers which can be detachably mounted on the housing, each support cover being made in the form of a bearing sleeve, which are made identical and which can be installed from the exterior of the housing in the spindle passage of the housing, preferably can be screwed in. By dismounting the two support covers and the flanges, both the slide bearing elements of the two support covers as wearing parts can be replaced, and also the passage for media in the housing is comfortably accessible from the spindle passage so that here wearing parts which potentially are located here in the passage for media can also comfortably be replaced if necessary.
For especially advantageous embodiments the spindle passage of the housing is stepped such that its diameter in the region bordering the ball body of the ball spindle located in the housing is slightly larger than the outside diameter of the ball body and in the region nearer the exterior of the housing is larger in comparison. In this configuration of the spindle passage, the installation of bearing sleeves which can be screwed in is made especially simple and reliable because the bearing sleeves which are matched to the spindle passage and which are therefore likewise stepped on the exterior can be screwed in as far as contact with the steps, the steps effecting exact axial positioning of the bearing sleeves.
In an especially advantageous manner, the arrangement can be made such that bearing seats stepped on the inside of the bearing sleeves for slide bearing bushes are formed which are located axially at a distance from one another and between which there is an O-ring. In an optionally required replacement of wearing parts the slide bearing elements therefore can be replaced separately, while the bearing sleeves themselves can be further re-used.
In an especially advantageous manner, in the passage of the housing for the media in each section adjoining the ball body there can be a sleeve body which forms a sealing shell in interaction with the ball body and which in passage through a spring arrangement is pretensioned against the ball body. This construction ensures not only perfect sealing due to the resilient contact of the sleeve body with the ball body of the ball spindle, but the sleeve bodies can also be replaced separately as wearing parts from the spindle passage when the spindle body is dismounted from the spindle passage after removal of the support cover.
For optimum operating behavior, for ball spindles and sealing shells there can be a pairing of material of an alloy based on cobalt or an aluminum-copper alloy and the slide bearing bushes can be formed from a copper-aluminum alloy.
In especially advantageous embodiments, on both ends of the passage for the media on the respective exterior of the housing, there can be a flange attached by screws with an integrated connection piece for forming the connections to the fluid system.
Especially advantageously the arrangement here can be made such that the identically made flanges have a pipe socket which projects into the passage for the media, whose end forms a support for a corrugated spring washer which pretensions the respective sleeve body for sealing against the ball body of the ball spindle.
The invention is explained in detail below using the embodiments shown in the drawings.
The embodiments of the ball valve shown in the drawings have a one-piece valve housing 2 in the form of a rectangular cuboid. The flow path for the pertinent medium to be controlled is a passage which is centrally located in the housing 2 in the form of an opening 4. As the controllable blocking element for blocking and clearing the flow path, in the housing 2 with an axis perpendicular to the opening 4, a ball spindle 6 is pivoted which forms between two end sections 8 and 10 a ball body 12 which, as is conventional in ball valves, forms the actual blocking body of the ball spindle 6. For this purpose, the ball body 12 has a flow opening 14 which is adjustable by turning the ball spindle 6 to the opening 4 of the housing 2 which forms the passage for the media. To switch the ball valve by turning the ball spindle 6, on a shoulder 16 of the end section 10 of the ball spindle 6 which is at the top in
The ball spindle 6 is pivoted on its two identically made end sections 8 and 10. The support is formed on the two end sections 8, 10 by one support cover at a time which are made in the form of support sleeves 26. They are made the same as so-called identical parts and from one side of the housing 2 and the other are installed in the spindle passage 28. The latter is stepped such that its diameter in the inner end section which is adjacent to the ball body 12 of the ball spindle 6 is slightly larger than the outside diameter of the ball body 12 and in the region nearer the exterior of the housing 2 is larger in comparison. In the illustrated examples in which the support sleeves 26 are installed in the housing 2 by screwing down, the spindle passage 28 in the widened outer region has an inside thread 30 into which the pertinent bearing sleeve 26 with an outside thread can be screwed. Due to the stepped shape of the spindle passage 28, the support sleeve 26 which is stepped in a suitable manner when it is screwed into the spindle passage 28 is in contact with the step 32 located in the passage and thus is axially positioned in the screwed-in state. The inside of the bearing sleeves 26 is likewise stepped in order to form bearing seats for the inner slide bearing bushes 34 and outer slide bearing bushes 36 between which there is a small intermediate space in which an O-ring (numbered 62 in
In the opening 4 which forms the passage for the media, on each section bordering the ball body 12 there is a sleeve-like sealing shell in the form of a sleeve body 38 with a sealing edge 40 matched to the outside arch of the ball body 12 and an O-ring 42 located at half the sleeve length for sealing against the housing opening 4. The sleeve bodies 38 are each elastically pretensioned against the ball body 12. A spring element which is designed for this purpose, in particular a corrugated spring washer 44 or a plate stack, is supported on a pipe socket 46 which extends from a flange 50 attached by screws 48 to the housing 2 into the housing opening 4 against which it is sealed with an O-ring 52. The identically made flanges 50 each have a connecting piece 54 for forming the connection to a fluid system which is not shown. The connecting pieces 54 can be covered by a protective hood 56 which is clipped on for purposes of storage and shipping.
When the support sleeves 26 are dismounted on both support end sections 8 and 10, all bearing bushes 34 and 36 can be replaced as wearing parts. For bearing sleeves 26 which have been removed on both sides, within the spindle passage 28 enough free space is available to replace the sleeve bodies 38 as wearing parts from the inside of the spindle passage 28. These advantages include the advantage that the ball valve can be efficiently and economically produced because it is assembled from identically made so-called identical parts, specifically, two identical flanges 50, identical support covers in the form of support sleeves 26, identical bearing bushes 34 and 36 and identical sleeve bodies 38 which are pretensioned with an identically made spring arrangement each.
While in the example from
