DK2405142T3 - CENTRIFUGAL PUMP COMPONENT. - Google Patents

Description

Centrifugal pump rotor component Description [0001] The invention concerns a centrifugal pump component, comprising at least one installation part and a split ring, as well as a method for its fabrication.

[0002] Split rings and their configuration are known in many variants in the literature. These are usually fabricated as single components and then installed in a pump casing or an impeller, i.e., being an installation part. Between the split ring and its mating component a hydraulic gap is always formed. The possible minimum gap is limited in the case of rigid, single-piece designs, since one must always allow for manufacturing tolerances.

[0003] EP 2 148 096 A1 shows a multiple-piece arrangement for a split ring, being arranged on the impeller of the pump and sealed off against an opposite, sleeve-shaped segment. The drawback here is that the complicated seal can be destroyed during the installation. A flexible lip of the gap seal is applied during operation against the mating component due to the pressure difference being sealed. This results in increased power consumption and wear, which runs counter to the goal of improved efficiency. Furthermore, individual parts need to be mounted on the impeller and casing, which means additional expense.

[0004] DE 191 53 95 U shows the rigid single-piece design of a split ring, which additionally provides a transport security between impeller and split ring. A ring which is dissolvable in the gap during operation prevents a skewing or corroding. But being a cardboard ring, it lies directly in the hydraulic gap and increases by its thickness the minimum gap spacing. Moreover, the cardboard ring has to be additionally inserted and thus an additional installation step is required.

[0005] EP 0 005 159 Al shows a slip ring seal in which individual parts for installation, transport and storage are combined into a single unit.

[0006] GB 543 404 A shows the breaking open of a seal during installation in a centrifugal pump, making use of a time effect here.

[0007] The problem which the invention proposes to solve is to create a centrifugal pump component comprising an installation component, especially an impeller, and a split ring arranged thereon, so that a gap seal is made possible on the impeller of a centrifugal pump which is favorable in its fabrication and easy in its installation.

[0008] The solution calls for an auxiliary connecting element to be provided on the centrifugal pump component between the impeller and the split ring or within the split ring, the auxiliary connecting element being configured as a predetermined break point. Advantageously, the centrifugal pump component can be fabricated from split ring and impeller as a single piece. This centrifugal pump component is either produced directly from a single rough part or the split ring is connected to the impeller. This simplifies the handling during the installation in the mating component, which receives the centrifugal pump component made up of split ring and impeller. Once the centrifugal pump component has been mounted in the mating component, the split ring can be released from the impeller by breaking the predetermined break point.

[0009] In a further embodiment of the invention, the predetermined break point breaks when shear forces are applied in one direction. The predetermined break point is dimensioned such that the centrifugal pump component can be easily installed in the mating component, while the auxiliary connecting element firmly joins the impeller and the split ring. After the installation, it is possible to produce a minimum gap between impeller and split ring after loosening, when an additional load is present, especially when a different direction of the force flow than the installation direction is present, while the mating component and the split ring remain firmly and tightly joined to each other. An especially advantageous design of the predetermined break point is when this breaks off in the direction of rotation of the pump and blocks in the axial direction. It does not matter here if the resulting gap is radial, axial, or diagonal in nature, or whether the geometries contain regulating possibilities.

[0010] Furthermore, the possibility exists of making the impeller from a first material, especially metal, plastic, or ceramic. Since the impeller in its later function, such as an impeller in a centrifugal pump, may be subjected to especially rough conditions, it is important to select a suitable material for the application. Besides resistance to media, the weight of the component and the ease of fabrication also play an important role in the choice.

[0011] In a further embodiment, the split ring is made from a second material, especially metal, plastic or ceramic. The applications of the centrifugal pump demand a careful choice of the material pairing of split ring and impeller. The split ring according to the invention can be designed so that it is provided as a wearing part in the gap between impeller and casing.

[0012] The possibility exists of fashioning the auxiliary connecting element from a third material, especially from metal, plastic or ceramic. This makes possible any desired choice of the materials for the split ring and the impeller, while a different material can be chosen for the auxiliary connecting element, making possible a breaking of the predetermined break point under the desired shear force.

[0013] In a further embodiment, a labyrinth seal is formed between the impeller and the split ring. The arrangement of split ring and impeller in a centrifugal pump component enables the design of a high-precision sealing device in the form of a labyrinth seal. By the connecting of the two parts to the centrifugal pump component, the spacing and the arrangement are established, so that no further adjustment work is needed during the installation in the mating component.

[0014] It is possible to provide structures for self securing during operation on the split ring, especially threads in the direction of rotation of the impeller. In this way, the connection between split ring and mating component of the pump is self-secured, in particular the split ring has a thread corresponding to the rotation of the pump, so that it is more firmly tightened when a tangential loading of the gap occurs during a starting operation.

[0015] A designing of the centrifugal pump component as an injection molded part allows a film gate between the auxiliary connecting element and the predetermined break point, besides an easy fabrication of the split ring and the impeller.

[0016] Furthermore, the centrifugal pump component can be designed as a multiple-component injection molded part, especially when using different materials for impeller and split ring. In this way, by using incompatibilities of the materials employed, intermeshing labyrinth systems can also be produced, wherein generative methods are especially suitable for the production process. In this case, the predetermined break point is the boundary layer between the two components which cling to each other after the fabrication. The adhesion is much less than the strength of the two components or the loading during operation of the pump.

[0017] The invention furthermore concerns a method for mounting an impeller with a split ring which is arranged thereon into a centrifugal pump, wherein, in the first step, a single-piece part comprising an impeller and a split ring is joined to the mating component, the split ring being arranged between the impeller and the mating component, and in a further step the split ring is broken from the single-piece part at a predetermined break point. It is advantageous that no further installation work between impeller and split ring is needed when joining the centrifugal pump component to the mating component. When assembling the centrifugal pump, it is only necessary to mount one part in exact fit. After breaking the predetermined break point, impeller and split ring are optimally adjusted.

[0018] In a further embodiment of the method, the connection of the split ring to the casing takes place in a positively locking manner, in particular by way of threads, plugin or snap-action connections. This makes possible a simple and precise assembly. The connection can be reversible in design, so that a later replacement of the centrifugal 5 pump component is made possible.

[0019] In a further embodiment of the method, the connection of the split ring to the casing takes place in an integrally joined manner, in particular by way of adhesive bonding, welding or something comparable. It is advantageous that the assembly can ) be performed very easily here. Very robust connections can be produced by the material closure.

[0020] In a further embodiment of the method, the connection of the split ring to the casing takes place in a non-positive manner, in particular by way of locating fits, shrink i fits or comparable methods. In this variant, a secure connection of the centrifugal pump component to the mating component is made possible.

[0021] Further embodiments will result from the combination of the embodiments presented thus far and therefore are not further mentioned here. ) [0022] Sample embodiments of the invention are shown in the drawings and shall be described more closely below. There are shown:

Figure 1 an installation preparation and Figure 2 an enlarged detail of this.

[0023] Figure 1 shows an installation part in the form of an impeller 1. This can be used in a fluid work machine or a fluid force machine. In the case of a centrifugal pump, one or two split rings 2 can be provided to bound off the pressure regions. One ) suction-side and one pressure-side split ring 2 here serve to seal off a pump pressure chamber at mating surfaces located in the casing, not shown here. These split rings 2 are each joined by an auxiliary connecting element 3 to the impeller 1. The auxiliary connecting element 3 has a predetermined break point, not shown in Figure 1. After the installation part has been mounted in the casing, the split rings fit firmly in the casing. The impeller cannot turn in this state. By the breaking of the predetermined break point, the impeller 1 and split ring 2 are separated from each other and the smallest possible narrow hydraulic gap is formed between the components. Any roughness of the predetermined break point is easily ground down.

[0024] Figure 2 shows in an enlarged detail of Figure 1 the arrangement of the split ring 2 and the auxiliary connecting element 3 in relation to the impeller 1. The figure shows that three components can consist of three different materials. The choice of the materials depends on the requirements for the centrifugal pump and the detachability of the predetermined break point. The breaking can occur through a definite axial loading or a torque.

List of reference numbers [0025] 1. Impeller 2. Split ring 3. Auxiliary connecting element

Claims (13)

A centrifugal pump component comprising a built-in component, the built-in component being an impeller (1) and a splitting ring (2) arranged thereon, a part of the splitting ring (2) being mounted stationary with a counter component, preferably a housing, preferably mounted on the pump. characterized in that a connecting auxiliary element (3) is provided between the impeller and the split ring (2) or inside the split ring (2), the connecting auxiliary element (3) being designed as a predetermined breaking point. Centrifugal pump component according to Claim 1, characterized in that the fracture site breaks when applied by shear forces in one direction. Centnfugal pump component according to Claim 1 or 2, characterized in that the impeller is made of a first material, in particular of metal, plastic or ceramic. Centrifugal pump component according to Claim 3, characterized in that the split ring (2) is made of a different material, in particular of metal, plastic or ceramic. Centrifugal pump component according to Claim 4, characterized in that the connecting auxiliary element (3) is made of a third material, in particular of metal, plastic or ceramic. Centrifugal pump component according to one of Claims 1 to 5, characterized in that a labyrinth gasket is provided between the impeller and the split ring (2). Centrifugal pump component according to one of Claims 1 to 6, characterized in that self-securing structures are provided during operation on the split ring (2), in particular threaded fuses. Centrifugal pump component according to one of Claims 1 to 7, characterized in that the centrifugal pump component is provided as an injection-molded part. Centrifugal pump component according to one of Claims 1 to 8, characterized in that the centrifugal pump component is provided as a multicomponent injection molded part, in particular when using different materials for impellers and splitting (2). Method for mounting an impeller with at least one split ring (2) arranged thereon in a centrifugal pump, characterized in that a single part comprising an impeller) and a split ring (2) in the first step are inserted into the counter component, i.e. in the housing, and that in a subsequent step the split ring (2) is broken from the individual part at a predetermined breaking point. Method according to Claim 10, characterized in that the connection of the split ring (2) to the housing takes place in a positive manner, in particular through threads, plug or snap connections. Method according to claim 10, characterized in that the connection of the split ring (2) with the housing takes place in a fabric-fitting manner, in particular through gluing, welding or the like. Awa # 160215 Method according to claim 10, characterized in that the connection of the split ring (2) to the housing takes place in a force-fitting manner, in particular through fitting, shrinking or the like. Awa # 160215