Rotor guard cap, rotor and shredder with rotor guard cap

Abstract

The present application relates to a rotor protection cap (10) for a rotor (100) of a comminution unit (200), wherein the rotor protection cap (10) has an outer surface (12) convex along a circumferential direction for protecting a hub (102) of the rotor (100), wherein the outer surface (12) has a projection (14) extending from it, wherein the projection (14), with respect to its position along the outer surface (12), extends in a first direction (16) perpendicular to the outer surface (12), in a second direction (18) parallel to the outer surface (12) and along the circumferential direction, and in a third direction (20) parallel to the outer surface (12) and perpendicular to the circumferential direction, wherein the projection (14) is larger in the first and second directions (16, 18) than in the third direction (20).

Description

TECHNICAL FIELD

[0001] The present invention relates to a rotor protection cap for a rotor of a comminution unit, wherein the rotor protection cap has an outer surface convex along a circumferential direction for protecting a hub of the rotor. BACKGROUND

[0002] Rotor protection caps of the above technical field are known from the prior art. They are used in particular in shredders to protect a shredder rotor located in the shredding chamber from wear. For example, international patent application WO 2009 / 156432 A1 discloses a shredder rotor comprising a drum with a central hub configured to rotate about a rotational axis. Several rotor protection caps are arranged around this hub, which together form an outer surface of the drum.

[0003] The well-known rotor protection caps serve to cover the internal parts of the rotor, in particular the hub and the components attached to it, and thus protect them from violent impacts caused by the material to be shredded and from the associated wear.

[0004] Since rotor protection caps themselves are subject to very high wear, they must be replaced regularly. This leads to the need to be able to replace the rotor protection caps as quickly and as effortlessly as possible in order to achieve the shortest possible downtime of the shredding unit.

[0005] Furthermore, there is a need to maximize the effectiveness of shredding the material to be shredded. In doing so, various effects during shredding must be taken into account, some of which reinforce and some of which compensate for each other.

[0006] DE 10 2010 022 492 A1 discloses a rotor protection cap for a rotor of a shredding unit. To enable the rotor protection cap to be installed in the shredding unit with less effort, it is proposed that, when new, the rotor protection cap be provided with at least one attachment point protruding from a striking surface, to which a support means can be coupled.

[0007] CN 2 13 376 942 U concerns a rotor protection cap for a hammer crusher, on the outside of which a projection with an opening is welded.

[0008] DE 39 38 725 A1 discloses a rotor protection cap with grooves through which hammers can protrude radially.

[0009] DE 11 04 301 A describes a hammer crusher with a rotor which carries impact cams or hammers in several rings at axial distances from one another. PRESENTATION OF THE INVENTION

[0010] Against this background, it is an object of the present invention to provide a rotor protection cap of the above technical field which maximizes the crushing efficiency and which is easily and quickly replaceable.

[0011] This object is achieved by a rotor protection cap according to claim 1. Advantageous embodiments of the invention emerge from the subclaims. The invention also relates to a rotor with such a rotor protection cap and to a shredder with such a rotor in a shredding chamber enclosed by walls.

[0012] A rotor protection cap for a rotor of a comminution unit has an outer surface that is convex along a circumferential direction to protect a hub of the rotor. The circumferentially convex design of the outer surface does not preclude additional convexity, or concavity, in the axial direction; however, the circumferential convexity is dominant. A slight two-dimensional convexity, also referred to as "congealment," is possible for the invention, as long as the rotor protection cap is more clearly convex in the circumferential direction. This makes it possible to combine the rotor protection cap with other similar rotor protection caps to form an approximately annular or approximately cylindrical rotor protection surface.

[0013] The outer surface, which is convex along the circumferential direction, can have a continuous curvature or be constructed in a facet-like manner from several flat or curved partial surfaces in order to achieve an approximation of a convex curvature in a manner that is simple to manufacture.

[0014] In other words, the outer surface is designed such that, when expertly assembled, it forms the outer surface, or more precisely, a portion of the outer surface, of a substantially cylindrical rotor drum. The rotor drum, as a whole, has a substantially cylindrical shape, although the shape of the rotor drum deviates to a limited extent from a mathematical cylinder in which a base surface is displaced over a fixed distance, for example, due to impact elements, interfering edges, fastening elements, or the like, or due to periodic or non-periodic deformations along the axial direction of the rotor drum.

[0015] The outer surface has at least one projection protruding therefrom, which, relative to its position along the outer surface, extends in a first direction perpendicular to the outer surface, in a second direction parallel to the outer surface and along the circumferential direction, and in a third direction parallel to the outer surface and perpendicular to the circumferential direction, wherein the projection is larger in the first and second directions than in the third direction. The first, second, and third directions are always defined relative to a single projection and can differ from projection to projection due to different positions of the projections along the circumferential direction of the rotor protection cap.

[0016] The projection protrudes like a shark fin from the outer surface of the rotor cap or rotor drum.

[0017] The protrusion creates a non-uniform outer surface of the rotor protection cap. This leads to the beneficial effect of improved shredding performance of the shredding unit, as the protrusion stimulates turbulence in the material flow during operation. Furthermore, the protrusion makes the rotor protection cap easier to handle during replacement, simplifying and accelerating the replacement process. This is made possible, for example, by the protrusion being used as a handle or even, with appropriate design, as an eyelet for a crane hook.

[0018] Preferably, the rotor protection cap has a plurality of projections that are larger in the respective first and second directions than in the respective third direction. This enhances the aforementioned advantageous effects of improved comminution performance and easier handling.

[0019] The quality of the product produced by the shredding unit and optional downstream equipment from the input process material is assessed, among other things, by the degree of shredding. The value of a shredding unit can therefore also be quantified by how effectively and efficiently it can shred, and to what size.

[0020] For example, the quality of a shredded scrap product produced by a shredder as a preferred shredding unit and the downstream equipment, usually an FE end product, is assessed by the achieved purity, in particular its CU content, and its bulk density.

[0021] Interfering edges, hammer tools and the like arranged in a comminution chamber cause shock and impact stresses on the process material, which deform and crush the process material.

[0022] But the impact processes between the particles of the process material moving in this space also represent an essential component of the material stress and contribute greatly to a good deformation effect of the crushing unit on the process material, which in turn positively influences the bulk density of the product.

[0023] The protrusion(s) of the rotor protection cap significantly increase the number of interfering edges in the comminution chamber, thus acting as a stimulator of movement for the process material, whose movement is altered uncontrollably in all directions depending on the angle of impact. This increases the degree of turbulence of the process material in the comminution chamber. This also increases the deformation effect of the comminution unit due to increased impact stress on the process material.

[0024] At the same time, the projection(s) of the rotor protection cap are lighter and less complex to manufacture and install than, for example, pivotally mounted hammers, and are more resilient and effective than interfering edges. Due to their small extension along the third direction, i.e., along the rotor's rotational axis, the projection(s) can exert particularly effective impulses on the process material, as this achieves a wider range of different impact directions, which results from the respective angle of impact of the process material on the respective projection. This also results in different trajectories for the individual particles of the process material, which in turn leads to more effective comminution.

[0025] Furthermore, the projection is formed integrally with a web inside the rotor protection cap. An integral or one-piece design of the projection is particularly reliable and wear-resistant. One-piece construction can be achieved, for example, by a material connection through welding or similar. This allows the rotor protection cap to be used for a longer period of time before the projection separates from the rotor protection cap due to wear.

[0026] Preferably, the projection or projections in the first and second directions are twice as large or larger than in the third direction.

[0027] This particularly large size ratio makes the advantageous effects of the invention particularly pronounced, particularly the resistance combined with ease of manufacture and assembly, as well as the effectiveness of the resulting impulses. Particularly good results can be observed with the process material starting at twice the size in the first and second directions compared to the third direction.

[0028] In a preferred embodiment, the projection(s) is / are each formed with an opening. The opening facilitates handling of the rotor protection cap during assembly or disassembly. The projection can thus additionally serve particularly well as a mounting eyelet for a crane or the like, without impairing the effectiveness of the respective projection.

[0029] Preferably, the projection(s) is / are delimited in the second direction by two flanks, each of which is / are formed with a different inclination relative to the outer surface. The flanks in the direction of rotation of the rotor form the main impact surface of the respective projection on the process material. The opposing flanks primarily serve to support the respective projection in order to safely dissipate the force absorbed by the projection upon impact to the rotor protective cap and the rotor. Inclined flanks are advantageous in this context because they enable greater strength of the projection(s).

[0030] Advantageously, the projection(s) is / are permanently attached to the rotor protective cap. Projections that are detachably attached to the rotor protective cap are more susceptible to premature wear because the detachable attachment means often partially protrudes from the outer surface of the rotor protective cap and thus comes into highly abrasive contact with the process material. Projections that are permanently attached to the rotor protective cap can be more easily secured, for example, entirely within the space enclosed by the outer surface, thus avoiding this disadvantage. For example, a positive-locking attachment of the projection to the rotor protective cap can be provided.

[0031] The rotor protection cap preferably has one, two, or three projections. Multiple projections per rotor protection cap allow for a reinforcement of the technical effect achieved by a single projection while simultaneously allowing for quick and easy installation. Since a tightly spaced arrangement of multiple projections weakens their effect, it may be advantageous to provide only one projection, depending on the size of the rotor protection cap.

[0032] The rotor protection cap preferably has a fastening means for attaching the rotor protection cap to the rotor. The fastening means can be, for example, an eyelet, a hook, an opening or a recess in a web, a projection, a groove or a tongue, or the like in the area enclosed by the rotor protection cap, i.e., on the side of the outer surface opposite the projection(s). Thus, the rotor protection cap can be mounted quickly, safely, and reliably directly or indirectly to the hub of the rotor.

[0033] In a preferred embodiment, the outer surface has a recess designed so that a hammer or striking element can pass through it during operation of the rotor from within the space enclosed by the rotor protective cap to the outside through the outer surface. As an alternative to this embodiment with a recess, it is possible to dispense with a hammer or a similar striking element passing through a recess. Further alternatively, a rotor protective cap can be omitted at the location on the rotor where a hammer or the like is provided.

[0034] The recess of this preferred embodiment allows for better protection of the rotor hub while allowing a hammer to be applied to the area covered by the protective cap.

[0035] An advantageous rotor has a rotor protection cap as shown in the preceding description. A preferred shredder has such a rotor in a shredding chamber enclosed by walls.

[0036] Preferably, the walls have shredding projections extending in the circumferential direction of the rotor and in the radial direction of the rotor. This allows the operating principle of the projections on the rotor protection cap to be transferred to one or more walls of the shredder and utilized there. This allows for further enhancement of the final product produced from the process material.

[0037] Preferably, the shredder projections of the shredder wall(s) extend toward the rotor and along a rotational direction of the rotor by a greater amount than in a direction along a rotational axis of the rotor. This unevenly distributes the inner surface of the shredder chamber. This leads to the beneficial effect of improved shredding performance of the shredder because the shredder projections stimulate turbulence in the material flow during shredder operation. Furthermore, the shredder chamber wall equipped with the shredder projection can be more easily handled during replacement thanks to the shredder projection, which simplifies and accelerates the replacement process.

[0038] Further advantages and developments of the invention will become apparent from the following description of the figures and the entirety of the claims. SHORT DESCRIPTION OF THE FIGURES Fig. 1 shows a preferred rotor protection cap with three projections. Fig. 2 shows another preferred rotor protection cap with two projections. Fig. 3 shows another preferred rotor protection cap with a projection. Fig. 4 shows a system of several rotor protection caps, which together form an approximately cylindrical rotor protection surface with projections protruding from it. Fig. 5 shows a preferred rotor including a hub with hammers arranged thereon and a system of several rotor protection caps with recesses or omitted rotor protection caps. Fig. 6 shows a sectional view of a preferred shredder having a shredding chamber with shredding projections arranged on walls of the shredding chamber. WAYS OF IMPLEMENTING THE INVENTION

[0039] Fig. 1 shows a preferred rotor protection cap 10 with three projections 14. The three projections 14 protrude from an outer surface 12 which is convex along a circumferential direction to protect a Fig. 1 not, but for example in Fig. 5, protrude outwardly from the hub 102 of a rotor 100. The projections 14 are configured in a shark fin manner, which in the present context means that, relative to their respective position along the outer surface 12, they are larger in a first direction 16 perpendicular to the outer surface 12 and in a second direction 18 parallel to the outer surface 12 and along the circumferential direction than in a third direction 20 parallel to the outer surface 12 and perpendicular to the circumferential direction. The circumferential direction, to which the second direction 18 and third direction 20 refer, can be determined directly with respect to the convexity of the outer surface 12.

[0040] The rotor protection cap 10 is designed in such a way that, together with other rotor protection caps, it forms an approximately cylindrical rotor protection surface. Such a surface is, for example, Fig. 4 and Fig. 5, which will be discussed in more detail below. In Fig. 1, the outer surface 12 has a facet-like structure, which means that in this case it is constructed from five facets that merge into one another, the transition between which is each marked by a kink. The individual facets are in turn flat, so that the planes and the transitions bent between them create an approximate curvature, which in the present context is to be understood as forming the convex outer surface and easily enables the person skilled in the art to distinguish the outer side of the rotor protective cap 10 from the inner side of the rotor protective cap 10. In the interior, i.e. on the side facing away from the outer side 12, there is a fastening means 28 in the form of, in this embodiment, an opening in a web 29. Various other fastening means 28 are conceivable alternatively or additionally, for example eyelets, hooks, recesses, projections, grooves or tongues.

[0041] The projections 14 are in the Fig. 1, the projections 14 are formed integrally with the rotor protection cap 10. They are part of the web 29 arranged within the outer surface 12 and protrude outward through the outer surface 12. This eliminates the need for additional fastening of the projections 14 to the outer surface 12 of the rotor protection cap 10, which makes the projections particularly robust.

[0042] The core of the present invention lies in the provision of the shark fin-like projections 14, which, due to their arrangement and design, result in an unevenness of the outer surface 12 of the rotor protection cap 10. This unevenness leads to the advantageous effect of improved shredding performance of the shredding unit. In the present case, the rotor protection cap 10 is a rotor protection cap 10 for the rotor of a shredder as a preferred embodiment of a shredding unit.

[0043] The Fig. The projection 14 shown centrally in Figure 1 has an opening 22 that is not provided in the other two projections 14 of this embodiment. This opening 22 facilitates handling of the rotor protection cap 10 during its assembly or disassembly on or from the rotor because, for example, a hook of a crane or the like can be hooked onto it, allowing the rotor protection cap 10 to be transported and held particularly easily during assembly.

[0044] The projections 14 of the Fig. 1 are shaped differently. In addition to the opening 22, which is only provided in the central projection 14, a front first flank 24 and a rear second flank 26 of the respective projections 14 are also designed differently. The first flank 24 is preferably inclined, i.e. it forms an angle other than zero to the first direction 16. The second flank 26 is also preferably inclined with respect to the first direction 16. The inclination of the first and second flanks 24, 26 can be designed differently from projection 14 to projection 14. This leads, on the one hand, to different strength properties of the respective projection 14 and, on the other hand, if the respective projections 14 have an uneven shape, to further non-uniformity of the surface.

[0045] The unevenness of the surface, in turn, leads to a higher quality of the shredded product output by the shredder. Furthermore, the first and second flanks 24, 26 can be configured, in particular inclined, depending on the size of the respective projection 14.

[0046] A transition between the first flank 24 and an outer surface of the projections 14 is in the Fig. 1 shown embodiment rounded.

[0047] Fig. Figure 2 shows a further embodiment of a preferred rotor protection cap 10, which differs from the one shown in Fig. 1 in particular in that only two projections 14 are provided here. However, both projections 14 have an opening 22 for easier handling. Furthermore, the projections 14 each have first and second flanks 24, 26 running perpendicular to the outer surface 12. The projections 14 are in the Fig. 2 are arranged and dimensioned such that they extend over a kink between adjacent facets. They follow the orientation of the facets, thus extending in the first direction 16 by an equal length, so that they each contain two flat parts and a kink, which can be considered a transition between the two flat parts and can be viewed as an extension of the kink of the facets abutting at this point.

[0048] Fig. Figure 3 shows another preferred embodiment of a rotor protection cap 10, which differs from the first embodiment shown in the number and configuration of the projection 14. In contrast to the first embodiment, the third embodiment has only one projection 14, which approximately corresponds to the central projection 14 of the first embodiment and has the opening 22, but is arranged at a different location along the outer surface 12 of the rotor protection cap 10.

[0049] In addition to the three previously described and in the Fig. In addition to the embodiments of the rotor protection cap 10 shown in Figures 1 to 3, there are also numerous other possibilities for designing the rotor protection cap 10. For example, even more projections 14 or even differently shaped projections 14 can be provided. The projections 14 can also be arranged not in alignment, but offset from one another along the third direction 20, in order to further increase the unevenness. However, an aligned arrangement of the projections 14 makes it possible to utilize the preferably integral design with the web 29 within the outer surface 12.

[0050] Fig. Figure 4 shows a system of several rotor protection caps 10, which together form an approximately cylindrical rotor protection surface with projections protruding from it. Each of the Fig. 4 shown individual rotor protection caps 10 is according to the in Fig. 1 shown embodiment of a preferred rotor protection cap 10, which is why a detailed description of the individual rotor protection caps 10 is omitted. In Fig. 4 the approximately cylindrical shape can be clearly seen, which results from the arrangement of the rotor protection caps 10 around the hub 102 of the rotor 100 (both in Fig. 5 shown).

[0051] Fig. 5 shows similar to the Fig. 4, the rotor protection caps 10 are attached to the hub 102 of the rotor 100. The rotor 100 according to Fig. 5 has, in addition to the rotor protection caps 10 with their projections 14 on its outer surface, recesses through which hammers 30 protrude through the outer surface otherwise formed by the outer surfaces 12 of the rotor protection caps 10.

[0052] The hammers 30 represent additional impact elements that protrude from the surface when the rotor 100 is in use due to the centrifugal force generated during operation. However, they are not rigidly attached to the hub 102 of the rotor 100, so that they can also withstand particularly large forces. To allow the hammers 30 to move accordingly, the outer surface of the rotor is interrupted at this point, which can be achieved by omitting a rotor protective cap 10 in place of a hammer 30. Alternatively, it is also possible to design the rotor protective cap 10 accordingly by having a recess designed such that a hammer 30 or an impact element can pass through it from within the space enclosed by the rotor protective cap 10 through the outer surface 12 to the outside during operation of the rotor 100.

[0053] Fig.6 shows a sectional view of a preferred shredder 200 having a shredding chamber 204 with shredder projections 206 arranged on walls 202 of the shredding chamber 204. The shredder projections 206 are attached to several walls 202 of the shredding chamber 204 such that they also protrude into the shredding chamber 204 in a shark fin-like manner. The orientation of the shredder projections 206 is based on the hub of the rotor 100 and the rotation direction of the motor defined thereby.

[0054] These shredding projections are also preferably configured perpendicular to the outer surface 12 of the rotor protection caps 10 arranged on the rotor 100 and parallel to this outer surface and along the circumferential direction of the rotor, larger than in a third direction parallel to the outer surface and perpendicular to the circumferential direction, i.e. parallel to the hub.

[0055] The illustrated embodiments of the rotor protection cap 10 make it possible to handle the rotor protection cap 10 more easily, particularly during assembly or disassembly, and thus reduce the downtime of the shredder when replacing such a rotor protection cap 10. Furthermore, the preferred embodiments achieve improved shredding performance of the shredder 200 by inducing turbulence in the material flow through shark fin-like disruptive elements integrated into the rotor protection cap 10 or the wall 202 of the shredder chamber 204.

[0056] The quality of the shredded scrap product produced by the shredder 200 and the downstream systems is essentially assessed by the achieved purity, i.e., in particular, the copper content, and the bulk density of the ferrous end product. As is known, the disruptive edges and hammer tools arranged in the shredder chamber 204 subject the process material to impact and impact stresses, which deform and also crush the process material. The preferred design of the rotor protection caps 10 with the projections 14 or the wall 202 with the shredder projections 206 results in the impact processes between the process material particles moving in the shredder chamber 204 experiencing an additional crushing effect, which can significantly improve the bulk density of the ferrous end product.

[0057] Primarily by the projections 14, preferably also in combination with the shredder projections 206, the number and intensity of the impact processes between the particles of the process material moving in the shredder chamber 204 is increased and intensified, thereby increasing the degree of turbulence of the process material in the shredder chamber 204 and thus overall increasing the deformation effect of the shredder 200 due to an increased impact stress on the process material.

[0058] Thus, the present invention provides a rotor protection cap 10 which maximizes the comminution effectiveness of a comminution unit, in particular a shredder 200, and which is easily and quickly replaceable. LIST OF REFERENCE SYMBOLS 10 Rotor protection cap 12 Exterior surface 14 lead 16 first direction 18 second direction 20 third direction 22 Opening 24 first flank 26 second flank 28 fasteners 29 steps 30 hammers 100 rotors 102 hub 200 shredders 202 wind 204 shredding room 206 Shredder protrusion

Claims

[1] Rotor protection cap (10) for a rotor (100) of a shredding unit (200), wherein the rotor protection cap (10) has an outer surface (12) convex along a circumferential direction for protecting a hub (102) of the rotor (100), wherein the outer surface (12) has a projection (14) protruding therefrom, wherein the projection (14), relative to its position along the outer surface (12), extends in a first direction (16) perpendicular to the outer surface (12), in a second direction (18) parallel to the outer surface (12) and along the circumferential direction and in a third direction (20) parallel to the outer surface (12) and perpendicular to the circumferential direction, wherein the projection (14) is larger in the first and second directions (16, 18) than in the third direction (20) and wherein the projection (14) is formed integrally with a web (29) in the interior of the rotor protection cap (10). [2] Rotor protection cap (10) according to claim 1, wherein the projection (14) is twice as large in the first and second directions (16, 18) as in the third direction (20) or larger. [3] Rotor protection cap (10) according to claim 1 or 2, wherein the projection (14) is formed with an opening (22). [4] Rotor protection cap (10) according to one of the preceding claims, wherein the projection (14) is limited in the second direction (18) by two flanks (24, 26) which are formed with mutually different inclinations relative to the outer surface (12). [5] Rotor protection cap (10) according to one of the preceding claims, wherein the projection (14) is formed inseparably with the rotor protection cap (10). [6] Rotor protection cap (10) according to one of the preceding claims, wherein the projection (14) is formed integrally with the rotor protection cap (10). [7] Rotor protection cap (10) according to one of the preceding claims, wherein the rotor protection cap (10) has one, two or three projections (14). [8] Rotor protection cap (10) according to one of the preceding claims, wherein the rotor protection cap (10) has a fastening means (28) for fastening the rotor protection cap (10) to the rotor (100). [9] Rotor protection cap (10) according to one of the preceding claims, wherein the outer surface (12) has a recess which is designed such that a hammer (30) or a striking element can pass through it during operation of the rotor (100) from within the space enclosed by the rotor protection cap (10) through the outer surface (12) to the outside. [10] Rotor (100) with a rotor protection cap (10) according to one of the preceding claims. [11] Shredder (200) with a shredding chamber (204) enclosed by walls (202) in which a rotor (100) according to claim 10 is arranged. [12] Shredder (200) according to claim 11, wherein the walls (202) have shredder projections (206) extending in the circumferential direction of the rotor (100) and in the radial direction of the rotor (100). [13] The shredder (200) of claim 12, wherein the shredder projections (206) extend toward the rotor (100) and along a direction of rotation of the rotor (100) by a greater amount than in a direction along a rotation axis of the rotor (100).

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