Conveying and processing screw for a comminuting machine and method for producing a conveying and processing screw

Abstract

The invention, which relates to a conveying and processing screw (1) for a comminuting machine and to a method for producing a conveying and processing screw (1), addresses the problem of specifying a solution which makes it possible to produce conveying and processing screws (1) easily and flexibly adapted to various tasks and to reduce the effort required for maintenance and for any adaption of the conveying and processing screw (1) to changing tasks and thus to reduce the costs for conversion, repair and maintenance measures. The arrangement solves this problem in that the conveying and processing screw (1) has a screw main body (2) with a hollow stub shaft (3) and the first screw flight (9) of the screw main body (2), and that on the hollow stub shaft (3) a separate, removable screw head (4) with a first screw flight (15) of the screw head (4) is arranged.

Description

[0001] Transport and working screw for a crushing machine and method for producing a transport and working screw

[0002] The invention relates to a transport and working screw for a shredding machine which operates according to a grinder principle and shreds animal or vegetable raw materials, wherein the transport and working screw has at least one screw flight and a knife pin.

[0003] The invention also relates to a method for producing a transport and working screw, in which the transport and working screw is provided with a screw flight and a knife pin.

[0004] State-of-the-art technology involves processing a wide variety of animal or plant raw materials at different temperatures using grinders. These animal or plant raw materials are referred to below as a processing product. Such processing products include foodstuffs of plant or animal origin, such as meat, cheese, fat, fish, skin, bones, and other food components.

[0005] For comminution of processed material, particularly in the meat industry, grinders with augers for feeding material to a cutting set are typically used as a device for comminuting a processed material, hereinafter referred to as a comminution machine. The thrust force for transporting the processed material in such a comminution machine is generated through the interaction of a transport and working auger, the processed material as the force transmitter, and a screw housing equipped with support elements. The achievable thrust force is achieved through the material's strength and the various states of force transmission.

[0006] Such shredding machines comprise at least one transport and working screw within a conveyor housing. A raw material receiving opening is arranged at a first end of the transport and working screw in a receiving area for feeding the material to be shredded. A cutting set is arranged at the second end of the transport and working screw. Such a cutting set comprises at least one perforated disc with openings and associated cutting tools such as knives. For simplicity, the transport and working screw is hereinafter referred to as the "conveyor screw."

[0007] DE 38 23 676 A1 describes a meat grinder, or rather a grinder-like shredding machine, that can be used in all areas of the meat industry. The meat grinder is designed so that a pressure chamber can be provided in the pressure housing, between the last flight of a conveyor screw and the cutting unit. The individual adjustment devices for limiting the pressure chamber can be operated from the outside and allow the pressure chamber to be adjusted to the prevailing operating conditions.

[0008] It is also known that such shredding machines employ cutting units consisting of a perforated disc and usually several knives rotating over a surface of the perforated disc as cutting tools for shredding the material. Alternatively, such shredding machines employ a cutting set comprising several combinations of perforated discs and knives.

[0009] The rotating blades of the cutting unit are connected to the conveyor screw by a blade pin, which drives them and sets them in rotation. This ensures that the conveyor screw and one or more blades always rotate in the same position relative to each other, running at the same speed as the conveyor screw and in a specific position synchronized with the conveyor screw.

[0010] The screw rotation generates the thrust pressure in the housing of the screw conveyor with the material to be processed up to the transfer point to the cutting unit.

[0011] The cutting tools forming the cutting unit are secured in position and clamped in front of the conveyor screw in a separate cutting unit housing, with the cutting unit housing being connected to the conveyor screw housing. The material to be processed is shredded in the cutting unit by means of the perforated disc, in a cutting set with several perforated discs, with the rotating cutting tools or knives in the knife chamber. The material to be processed is pressed into the knife chambers by the thrust pressure generated by the conveyor screw. The pressure in the knife chambers increases and the resulting chunky meat pieces (processed material) from the conveying process are compressed to such an extent that shaped elements or pins form on them in the bores of the outflowing perforated disc, which are pressed into the openings of the perforated disc, still connected to the meat piece.In this penetration form, the entire knife space content of all holes is pushed over the disc surface by the knives, penetrates into the holes and is pressed against the sharp edges of the holes in the perforated disc, thereby separating the tenons or shredding the material to be processed.

[0012] Various screw conveyors are known from the state of the art, which differ in size and geometric design of the screw flights of the screw conveyor.

[0013] The general purpose of such screw conveyors is to transport and compact the material in the shredding machine through the rotation of the screw conveyor and its flight. This is particularly intended to generate appropriate pressure in the area where the material is transferred to the cutting tools. This material compaction is a prerequisite for the material to penetrate the openings of the perforated disc and for the material to be separated by the cutting tool in the cutting set.

[0014] The forces acting on the screw conveyor during raw material intake, conveyance, and pressure buildup lead to high loads on the screw conveyor, the knife pin, and the entire cutting set, depending on the consistency of the material being conveyed. These loads are intensified when the material being processed has a high lumpy consistency or is subject to very low temperatures during processing in the shredding machine. These loads lead to wear on the components involved in the processing process, particularly on the cutting tools and the perforated disc.

[0015] For this reason, components such as cutting tools, blades, and perforated discs must be replaced. Replacement may also become necessary due to changing work tasks. If the degree of wear still allows, the components can be reworked, for example, by regrinding, and restored to working order. Such repair measures can also affect the housing.

[0016] Signs of wear on the conveyor screw occur particularly in an area of ​​the screw flight of the conveyor screw after a long period of use, which causes the pressure to build up in front of the cutting set, i.e. directly in a transfer area of ​​the material to be processed from the conveyor screw to the cutting set.

[0017] A disadvantage of the current state of the art is that the repair described above requires replacing the entire screw conveyor with a "new" one that is identical to the machine's original design. This is particularly costly when replacing the entire screw conveyor. Furthermore, a screw conveyor that is only worn in part of the screw conveyor must be disposed of entirely.

[0018] Furthermore, even when adapting to specific materials to be shredded, it is always necessary to replace the entire conveyor screw.

[0019] There is therefore a need for an improved transport and working screw and an improved method for producing a transport and working screw.

[0020] The object of the invention is now to provide a transport and working screw for a comminution machine and an improved method for producing a transport and working screw, which makes it possible to produce transport and working screws easily and flexibly adapted to different work tasks and to simplify the repair effort and the effort involved in adapting the transport and working screw to changing work tasks and thus reduce the costs for conversion as well as maintenance and repair measures.

[0021] The problem is solved by a transport and processing screw with the features according to claim 1 of the independent patent claims. Further developments are specified in the dependent patent claims.

[0022] According to the state of the art, it is usual for transport and working screws for a shredding machine that operates according to a grinder principle and shreds animal or vegetable raw materials to have at least a first screw flight and a knife pin.

[0023] According to the invention, the transport and working screw has a screw base body with a hollow shaft stub and the first screw flight of the screw base body and that a separate, removable screw head with a first screw flight of the screw head is arranged on the hollow shaft stub.

[0024] The screw base body is therefore shorter than a state-of-the-art transport and working screw, viewed along the longitudinal axis of the screw base body or the transport and working screw. Only after assembly, in which the screw head is positioned and secured on the hollow shaft stub of the screw base body, does the combination of screw base body and screw head reach the length of a state-of-the-art transport and working screw.

[0025] The task of the first screw flight of the screw body is to transport the material to be processed from a receiving area of ​​the shredding machine to the screw head, while the task of the first screw flight of the screw head is to generate thrust pressure, particularly for the transfer area in front of the cutting tool.

[0026] The transport and working screw according to the invention is provided with a screw base body with a hollow shaft stub. This hollow shaft stub has an outer diameter that is smaller than an average outer diameter of the screw base body without the first flight of the screw base body. The hollow shaft stub has a length in a direction of a longitudinal axis of the transport and working screw that is less than one-third of the total length of the transport and working screw.

[0027] For example, the screw base body according to the invention for a transport and working screw of a grinder size 300 has a length of approximately 917 mm, with the length of the hollow shaft stub being in a range between 200 mm and 250 mm.

[0028] The average outer diameter of the screw base body, without taking into account the first screw flight arranged on the surface of the screw base body, can, for example, be in a range between 100 mm or 160 mm and 120 mm or 170 mm, while the outer diameter of the hollow shaft stub is in a range between 60 mm or 120 mm and 80 mm or 130 mm.

[0029] The hollow shaft stub also has a central, cylindrical opening in the form of a counterbore. The depth of this central, cylindrical opening is 120 mm or 140 mm in one example.

[0030] Furthermore, it is intended that a worm head be arranged on the outer diameter of the hollow shaft stub, which is connected to the hollow shaft stub either permanently or detachably. For example, the worm head is positively connected to the hollow shaft stub and thus rotates in the direction of the worm body and at the same speed as the worm body. Furthermore, parallel keys between the components can enable force transmission during rotation.

[0031] The screw head has a first screw thread running around its surface, which is a continuation of the first screw thread of the screw base body arranged on the screw base body. It is provided that an outer diameter of the first screw thread of the screw base body corresponds to an outer diameter of the first screw thread of the screw head at a transition point between the first screw thread of the screw base body and the first screw thread of the screw head. In one embodiment, the pitch of the screw threads in the transition region is selected to be substantially equal.In this way, a continuous transport of the material to be processed is ensured by the transport and working screw according to the invention in the comminution machine over an entire transport path from the first end to the second end of the transport and working screw, i.e. also in the area of ​​the transition point on the transport and working screw.

[0032] Alternatively, the screw head has a first screw flight running around its surface, which has a greater pitch than the first screw flight of the screw body. For example, by means of a greater pitch of the first screw flight of the screw head compared to the first screw flight of the screw body, the material to be processed can be compacted at the second end of the transport and working screw in an area in which the material to be processed is transferred to the cutting set of the shredding machine, which is referred to in this description as the transfer area.

[0033] According to the invention, the screw head is designed to be replaceable. This allows a worn screw head to be removed from the main body of the transport and working screw and replaced with a new one.

[0034] This also makes it possible to remove the screw head from the main screw body of the transport and processing screw and replace it with another screw head with a different flight geometry for a different processing task. Such a screw head has, for example, a different pitch of its flight, a double flight geometry, i.e. two screw flights, or a double flight geometry with additional short cutting edges. Thus, the transport and processing screw according to the invention can be easily adapted to changing work tasks. In versions with two screw flights, these screw flights can have different pitches. The invention also provides for a separate, removable knife pin to be arranged on the hollow shaft stub of the main screw body.For example, the knife pin is positively connected to the hollow shaft stub and thus rotates in the direction of the screw base body and at the same speed as the screw base body.

[0035] This makes it possible to replace the knife pivot, for example, if it shows signs of wear. The knife pivot can also be easily adapted to changing work tasks or cutting tool or knife designs.

[0036] In particular, the screw head and the knife pin are designed to be independently mountable and dismountable on the hollow shaft stub of the screw body. This means that, for example, the knife pin does not need to be disassembled to replace the screw head, and vice versa.

[0037] Typically, the cutting tools, such as knives, are arranged with a plug-in and clampable connection at one end of the knife journal, where the knife journal is not connected to the hollow shaft stub. The knife journal, which is set in rotation by the screw base body with the hollow shaft stub, thus sets the cutting tools, such as knives, in front of a perforated disk of the cutting set in rotation. A further task of the knife journal is to fix the position of the knives relative to points on the screw head with the highest thrust pressures. This ensures effective transfer of the processed material from the screw flight or flights of the screw head in the transfer area to the cutting set. This ensures that the knife chambers of the cutting set are filled evenly and reliably.

[0038] It is particularly advantageous that a first position securing element is arranged between the hollow shaft stub and the screw head and / or a second position securing element is arranged between the hollow shaft stub and the knife pin.

[0039] To ensure that the screw head and / or the knife pin are positioned correctly and secured against mutual twisting on the hollow shaft stub of the screw body, appropriate position securing elements are provided.

[0040] A first position-locking element is arranged between the hollow shaft stub and the screw head. In particular, the first position-locking element is arranged in an area between an outer diameter of the hollow shaft stub and an inner diameter of the screw head. This first position-locking element secures the screw head to the hollow shaft stub in a rotationally secure manner. This arrangement and fixation is carried out in such a way that the screw geometry of the first screw flight of the screw body matches the screw geometry of the first screw flight of the screw head at the transition point between the screw flights.

[0041] Furthermore, a second position-locking element is arranged between the hollow shaft stub and the knife pivot. Specifically, the second position-locking element is positioned in an area between an inner diameter of the cylindrical opening of the hollow shaft stub and an outer diameter of the knife pivot. This second position-locking element secures the knife pivot in the hollow shaft stub, preventing it from twisting. In this way, up to 70% of the power required by the entire machine for shredding is transferred.

[0042] Such a torsion-proof arrangement of the components (hollow shaft stub, screw head, knife pin) relative to one another ensures that the components move in the same direction of rotation and at the same speed, even though, for example, only the first end of the screw base body is driven by a drive means.

[0043] The position securing elements are designed, for example, as parallel keys, with corresponding opposing grooves provided on the surfaces of the components to ensure the above-described arrangement of the components relative to one another and to secure them against force. The use of other position securing elements that secure the components against rotation, such as riveted joints or screws, is also possible. Alternatively, a force-transmitting round material can be used, which, similar to a parallel key, is provided with a profile on each half of the knife pin and in the hollow shaft, thus ensuring positional security.

[0044] In an alternative, the components can be glued together, whereby it is intended that the adhesive connection can be made detachable, for example by means of appropriate solvents or temperatures, in order to be able to separate the components from each other if necessary.

[0045] In a further alternative, the components are welded together at least locally, for example in a front position, so that the components can be separated from each other by removing the weld seam of the locally limited welded connection.

[0046] The position-locking elements generally ensure a drive connection between the components for joint rotation. They also ensure the correct position of the first flight of the screw body and the first flight of the screw head relative to each other, as well as the position of the knife pin. This also ensures the knife position relative to the conveying points for the raw material transfer and the ends of the flight of the screw head.

[0047] Furthermore, a locking washer is provided on the hollow shaft stub of the screw body to secure the screw head and the knife pin in position on the hollow shaft stub. This locking washer can be installed with a screw thread as a secure connection in the hollow shaft stub of the screw body.

[0048] Such a lock washer effectively prevents any change in the position of the components along the longitudinal axis of the screw base body or the transport and working screw. The lock washer features fastening elements that securely attach it to the end of the hollow shaft stub. Such fastening elements include screws.

[0049] The locking washer presses the screw head and the knife pin against the hollow shaft stub, thus preventing longitudinal movement of the components relative to each other. The force acting on the locking washer is very limited, since the design of the pitch of the first screw thread of the screw head and the direction of rotation of the transport and working screws cause pressure on the screw head caused by the material being processed, which also presses the screw head against the hollow shaft stub. Thus, the locking washer only needs to provide basic security for the components and can be designed accordingly small. This also applies to fastening elements such as screws.

[0050] In an advantageous embodiment of the invention, it is provided that short cutting edges are arranged on the screw head.

[0051] Several short cutting edges are arranged on the outer circumference of the screw head. These short cutting edges are preferably arranged in the middle between the side walls of the first screw flight of the screw head and parallel to these. These short cutting edges are intended for pre-cutting the material to be processed as it is transported to the cutting set, particularly in the last flight of the screw head. This allows, for example, a material to be processed at lower temperatures. Alternatively, a material with greater toughness or strength can be processed. Pre-cutting ensures that the material to be processed can penetrate the pin-shaped openings in the perforated disk of the cutting set more quickly, thus ensuring optimal comminution of the material.

[0052] The short cutting edges arranged between the screw flights are intended, for example, to separate the material to be conveyed, which is stuck to the wall of the conveyor housing, into smaller pieces when meat parts of the processing material are conveyed through the screw chambers of the screw flights, and thus to reduce the strength of the material to be conveyed, in order to be able to press it more easily with less pressure and in larger quantities into the cutting set to increase performance.

[0053] It is also planned to apply a hard metal coating to the first flight of the screw head and / or the short cutting edges. To reduce wear in the area of ​​the first flight of the screw head, the surface of this screw head is to be made more robust. This is achieved by coating the surface with a hard metal coating. This reduces wear on this screw head and improves the durability of this flight of the screw head.

[0054] In addition, the surface of the short cutting edges can also be coated with a hard metal layer in order to increase the stability of the short cutting edges or to reduce the wear of the short cutting edges.

[0055] The problem is solved by a method having the features according to claim 7 of the independent patent claims. Further developments are specified in the dependent patent claims.

[0056] In methods for producing a transport and working screw, it is provided that the transport and working screw is provided with at least a first screw flight and a knife pin.

[0057] The aim of the present invention is to design a section of the transport and working screw, located at the second end of the transport and working screw, as a separate component in the form of a replaceable screw head, for new and refurbished transport and working screws. This makes it possible to replace this part of the transport and working screw, which is subject to severe wear, without having to dispose of the entire transport and working screw. The severe wear in this area results from the fact that the material to be processed is transferred to the cutting set in the transfer area under increased pressure and counterpressure.

[0058] The aim is also to make it easy to adapt to a specific material to be shredded by changing the geometry of the first flights of the screw head and other elements of the screw head. Furthermore, a different screw head with the appropriate geometry can be provided for replacement, depending on the task.

[0059] This will reduce the costs of any necessary repair or retrofitting measures.

[0060] According to the invention, it is therefore provided that the transport and working screw is provided with a screw base body which has a hollow shaft stub and the first screw flight of the screw base body and that a separate, removable screw head with a first screw flight of the screw head is provided on this hollow shaft stub.

[0061] According to the invention, the components of the screw base body with its hollow shaft stub, screw head and knife pin are manufactured as individual parts and assembled in one assembly step to form a complete transport and working screw.

[0062] The hollow shaft stub according to the invention is provided at the second end of the screw base body or the transport and working screw in the area of ​​the cutting set of the comminution machine. This provision takes place during the manufacture of the screw base body for a new transport and working screw. Alternatively, a previously used transport and working screw, in which the area at the second end of the transport and working screw is worn in particular, can be converted into a screw base body with a hollow shaft stub and thus continue to be operated as a transport and working screw in a comminution machine as a repaired screw base body in conjunction with a new screw head.

[0063] During the assembly step, the screw head, which is designed as a separate component, is pushed onto the outside or circumference of the cylindrical hollow shaft stub and fixed with its first screw thread.

[0064] It is also planned to provide a separate, removable knife pin on the hollow shaft stub. The hollow shaft stub will be provided with a central, cylindrical opening into which the knife pin, designed as a separate component, will be inserted and secured during the assembly step.

[0065] After completion of these assembly steps concerning the screw head and the knife pin, the transport and working screw according to the invention is completely ready and can be used in the shredding machine.

[0066] Furthermore, the invention provides that the screw head is secured against rotation relative to the screw base body by means of a first position securing element and / or the knife pin is secured against rotation by means of a second position securing element.

[0067] The screw head and knife journal components are attached and fixed to the screw base body in such a way that the screw base body, which is set in a rotary motion, transmits or transfers this rotary motion to the screw head and knife journal. Position locking elements are used to ensure a rotationally secure attachment of the screw head and knife journal components to the screw base body. In one embodiment, a first position locking element is arranged in an area between an outer diameter or an outer surface of the hollow shaft stub and an inner diameter or an inner surface of the screw head.

[0068] A second position-locking element is arranged in an area between an inner diameter of the cylindrical opening or an inner surface of the hollow shaft stub and an outer diameter or an outer surface of the blade pin. These position-locking elements are designed as parallel keys and inserted into corresponding grooves arranged in the components. Such parallel key-groove combinations are known from the prior art. Alternatively, a force-transmitting round material can be used, which, similar to a parallel key, is inserted into grooves arranged in the components on each half side and ensures the anti-twist position locking.In a particular embodiment, it is provided that the first screw flight of the screw base body is provided with a pitch that differs from the first screw flight of the screw head and / or that hardened short cutting edges are provided on the screw head in spaces between the first screw flight of the screw head.

[0069] The first screw flight, located on the screw body, has a first pitch for receiving the raw material, while the first screw flight, located on the screw head, has a second pitch. The first pitch and the second pitch can be the same or different for generating thrust pressure to feed the material into the cutting set.

[0070] In one embodiment of the transport and working screw according to the invention, the second pitch of the first screw flight of the screw head has a smaller pitch than the first pitch of the first screw flight of the screw body. Such a design results in greater compaction of the material being processed in the shredding machine by the transport and working screw in the area of ​​the screw head. This greater compaction is very advantageous in the transfer area at the second end of the transport and working screw, since the cutting unit of the shredding machine is located in this area.

[0071] In a further embodiment, hardened short cutting edges are arranged on the circumference or outer surface of the screw head in the spaces between the first screw flight of the screw head. Several of these short cutting edges are preferably arranged in the middle between the side walls of the first screw flight of the screw head and parallel to these side walls. The short cutting edges are preferably arranged near the transfer area at the end of the screw flight of the screw head.

[0072] These sharp, short cutting edges rotate with the screw head and are designed to pre-cut the material during its transport to the cutting set. This allows, for example, material with very solid, coarse pieces or fragments to be processed more effectively at lower temperatures.

[0073] According to the invention, a second screw flight with a wedge-shaped feed cutting edge is arranged on the screw head and a first support surface is arranged at each of the ends of the first screw flight and the second screw flight, the first support surfaces being arranged opposite one another at an angle of 180 degrees.

[0074] The invention provides for a second screw flight to be arranged on the screw head, which is preferably located centrally between the side walls of the first screw flight of the screw head. At its beginning, this second screw flight has a wedge-shaped, rising intake edge that initially has a sharp edge. The function of this intake edge is to divide the flow of processing material conveyed from the screw flights to the beginning of the second screw flight into two mass flows or partial flows, which are then transported further in areas between the first screw flight and the second screw flight to the ends of the screw flights in the transfer area. The two partial flows exit the screw head at the ends of the screw flights opposite one another or offset by 180 degrees and are thus guided via the transfer area to the cutting set with the knives.

[0075] It is further provided that first support surfaces are arranged at the opposite ends of the first and second screw flights, which are offset by 180 degrees. These first support surfaces are characterized in that they have a surface in the shape of a circular ring section, wherein both surfaces lie in an imaginary first plane at the end of the screw head, which is aligned orthogonally to the longitudinal axis of the transport and working screw according to the invention. These first support surfaces generate a pressure or counterpressure in order to press the material to be processed against the cutting set with the knives. Starting from the first support surfaces, a first force effect is created in each case, which is directed parallel to the longitudinal axis in the direction of the cutting set.In particular, it is provided according to the invention that second support surfaces are arranged at a distance from the first support surfaces on the first screw flight and on the second screw flight, wherein the second support surfaces are arranged opposite one another at an offset angle of 90 degrees to the first support surfaces and at an angle of 180 degrees to one another, and that a displacement body is arranged on each second support surface.

[0076] Furthermore, it is provided that second support surfaces are arranged at a distance from the ends of the first and second screw flights and thus from the first support surfaces. These second support surfaces are arranged at an offset angle of 90 degrees to the first support surfaces. This offset angle is determined when viewing the end of the screw head, starting from the cutting tools or the transfer area. Thus, both the first support surfaces and the second support surfaces are arranged opposite each other at an angle of 180 degrees to each other.

[0077] The surfaces of the second support surfaces are also designed in the shape of a circular ring, with both surfaces lying in an imaginary second plane, which is also oriented orthogonally to the longitudinal axis. Thus, the first support surfaces lie in the first plane at the end of the screw head, which is spaced apart from the second plane in which the second support surfaces are arranged.

[0078] These second support surfaces also generate pressure or counterpressure to press the material being processed against the cutting set with the knives. A second force is generated from each of the second support surfaces, which is directed parallel to the longitudinal axis and parallel to the first force in the direction of the cutting set.

[0079] In one direction of movement of the partial streams of the processed material, seen in front of the two second support surfaces, a wedge-shaped displacement body is arranged on the corresponding screw flight. This displacement body has a pitch that is greater than the second pitch of the first screw flight of the screw head or greater than the pitch of the second screw flight of the screw head. In the area of ​​the displacement body, a reduction in cross-section results in additional displacement or compression of the processed material, i.e. a directed movement of the partial streams. This displacement or compression supports the second force effects emanating from the second support surfaces. This serves to fill the closed knife spaces with pressure-increasing processed material for the purpose of forming meat plugs in the decreasing perforated disk.

[0080] The first and second screw flights arranged on the screw head each have a pitch H over a complete rotation of the screw flights of 360 degrees. The position of the second support surfaces, which is the same as the end of the displacer, is selected such that a distance of H / 8 results between the first support surfaces and the second support surfaces along the longitudinal axis of the transport and working screw.

[0081] The screw head has a double flight geometry due to the first screw flight and the second screw flight. Due to the four support surfaces arranged at 90 degrees to one another, pressure is built up in the material to be processed due to the four forces acting towards the individual closed knife chambers of the cutting set, also in four areas offset by 90 degrees to one another. The invention creates a 4-point conveying profile for the material to be processed. This 4-point conveying profile enables all four knife chambers located in front of the knives of the cutting set to have the same fill level with the material to be processed and the same pressure conditions. Thus, the partial surfaces of the perforated disc are used almost equally in four areas and integrated into the comminution of the material to be processed, whereby a significant increase in the throughput of the material to be processed during comminution in the comminution machine is achieved.

[0082] The circular ring cutouts of the first support surfaces and the circular ring cutouts of the second support surfaces each have circular arcs belonging to a central angle, which lies in a range between 10 degrees and 30 degrees and is in particular 20 degrees. The central angle is arranged on the longitudinal axis of the transport and working screw. Viewed in the direction of the longitudinal axis, two adjacent support surfaces are offset from one another at an angle of 90 degrees. This arrangement, offset by 90 degrees from one another, also corresponds to the arrangement of four knives in the cutting set. Since the knives in the cutting set are driven by the knife pin, the positions and orientations of the four knives in relation to the four support surfaces and the forces associated with the support surfaces remain the same.Thus, due to the four forces, four knife chambers belonging to the knives are filled almost evenly with the material to be processed under almost the same pressure, which leads to an improvement in the throughput of the shredding machine.

[0083] The screw head according to the invention can thus be used in a shredding machine operating according to the grinder principle for the purpose of replacing transport and working screws that have been in use for a longer period of time. This also makes it possible to convert the transport and working screws to higher-performance technical solutions.

[0084] In addition, the screw head according to the invention is used in the new production of transport and working screws and thus enables simple replacement solutions for the particularly stressed screw head or a simple adaptation of the area of ​​the screw head to changed technologies.

[0085] It is also possible for the screw head according to the invention to be adapted to transport and working screws from different manufacturers, since the tools are used internationally in standardized sizes and thus have a high degree of dimensional uniformity, which the screws essentially follow. Alternatively, the screw head according to the invention can be adapted to various sizes of transport and working screws.

[0086] The screw head can be replaced at any time if necessary modifications or advanced wear occur, as only the high-precision part of the screw head is required for high-quality thrust generation by the transport and working screws, and can therefore be easily restored thanks to the screw head's interchangeability. The applicant provides the screw head as a commercial product for users and service companies, along with information on its implementation on all screw types, making it generally available for use.

[0087] The above-explained features and advantages of this invention will be better understood and appreciated after careful study of the following detailed description of the preferred, non-limiting exemplary embodiments of the invention with the accompanying drawings, which show:

[0088] Fig. 1: a screw base body with a cut hollow shaft stub and a screw head in a sectional view, Fig. 2: a part of the screw base body with the hollow shaft stub, the screw head and a knife pin after assembly of the separately manufactured components to a transport and working screw in a sectional view,

[0089] Fig. 3: a transport and working screw according to the invention in a

[0090] side view,

[0091] Fig. 4: the screw head according to the invention with two screw flights in a side view and

[0092] Fig. 5: a perspective view of the screw head according to the invention in connection with knives of a cutting tool.

[0093] Figure 1 shows, as components of the transport and working screw 1 according to the invention, a screw base body 2 with a cut hollow shaft stub 3 and a screw head 4.

[0094] At a first end 5 of the screw base body 2, a limit stop 6 and a means 7 for connecting the screw base body 2 to a drive unit (not shown) are arranged. Such a drive unit ensures rotation of the screw base body 2 and thus of the entire transport and working screw 1, which is arranged in a comminution machine (not shown).

[0095] The hollow shaft stub 3 is arranged at a second end 8 of the screw base body 2. A first screw flight 9 of the screw base body 2 is arranged on the screw base body 2 and has a first pitch, for example, for receiving the material to be processed. In the example of Figure 1, the outer diameter of the screw base body 2 changes in the direction toward the second end 8. This is exemplary and not a feature of the present invention.

[0096] The hollow shaft stub 3 has an outer diameter which is smaller than an average outer diameter of the screw base body 2 or a maximum outer diameter of the screw base body 2 at the second end 8 according to Figure 1. This refers to an outer diameter of the screw base body 2 which results without the first screw flight 9 of the screw base body 2.

[0097] The hollow shaft stub 3 has a length 10 in a direction of a longitudinal axis 11 of the transport and working screw 1 or the screw base body 2, which is less than one-third of the total length of the transport and working screw. In one example, the outer diameter of the screw base body 2 is approximately 10 mm, depending on the design.

[0098] 120 mm or 160 mm and the length 10 approx.145 mm or 190 mm.

[0099] The hollow shaft stub 3 further has a central, cylindrical opening 12 in the form of a counterbore. In one example, the depth 13 of this central, cylindrical opening 12 is a maximum of only 90% of the length 10 of the hollow shaft stub 3. In one example, the maximum depth 13 of the opening 12 is approximately 100 mm or 140 mm, depending on the embodiment.

[0100] Figure 1 also shows the screw head 4, manufactured as a separate component. The screw head 4 has a cylindrical base body 14, on which a first screw flight 15 of the screw head 4 is arranged. The first screw flight 15 of the screw head 4 has a second pitch.

[0101] Alternatively, the screw head 4 can have a cylindrical base body 14 on which the first screw flight 15 and a second screw flight 28 are arranged, as shown in Figure 1. In this way, a double flight geometry or a double-flight screw head is formed in the area of ​​the screw head 4. This occurs in particular in the vicinity of a transfer area 29, in which the material to be processed (not shown in Figure 1) is transferred from the screw head 4 to a cutting set of the comminution machine (also not shown). This transfer area 29 is shown in Figure 1 outlined by a dash-dash line.

[0102] The outer diameter of the hollow shaft stub 3 of the screw base body 2 is adapted to the inner diameter of the cylindrical base body 14 of the screw head 4 so that the screw head 4 can be pushed onto the hollow shaft stub 3.

[0103] In one example, the inner diameter of the cylindrical base body 14 of the screw head 4 is approximately 120 mm and a length 16 of the screw head 4 is approximately 200 mm.

[0104] To mount the screw head 4 on the hollow shaft stub 3 of the screw base body 2, the screw head 4 is moved in the direction shown by the arrow 30 in Figure 1.

[0105] Figure 2 shows a part of the screw base body 2 with the hollow shaft stub 3 and the first screw flight 9 of the screw base body 2, the screw head 4 and a knife pin 17 after assembly of the separately manufactured components to form a transport and working screw 1 according to the invention in an at least partial sectional view.

[0106] After the screw head 4 has been moved with the first screw flight 15 of the screw head 4 in the direction 30 shown in Figure 1 by the arrow during assembly of the transport and working screw 1, the screw head 4 reaches the position shown in Figure 2 on the hollow shaft stub 3. To ensure that the screw head 4 is arranged on the hollow shaft stub 3 in a rotationally secure manner, at least one first position securing element 18 is arranged between these two components. In the example in Figure 2, the first position securing element 18 is designed as a feather key, with two of these first position securing elements 18 being shown. Such feather keys are usually arranged in corresponding grooves machined in the hollow shaft stub 3 and in the screw head 4, in which grooves have also been machined.These first position securing elements 18 enable a transmission of a rotary movement from the hollow shaft stub 3 of the driven screw base body 2 to the screw head 4.

[0107] During assembly of the transport and working screw 1 according to the invention, a base 19 of the knife pin 17 is inserted and fixed into the central, cylindrical opening 12 of the hollow shaft stub 3, as is also shown in Figure 2.

[0108] In the example of Figure 2, the base 19 of the knife pin 17 has a pin 20 and a radial circumferential ring 21. The pin 20 is arranged in a bore 22 arranged in the central, cylindrical opening 12 of the hollow shaft stub 3 and corresponding to the pin 20. In this way, the knife pin 17 is arranged so as to be centered relative to the screw base body 2. The circumferential ring 21 is provided for further precise alignment of the knife pin 17 along the longitudinal axis 11. This circumferential ring 21 rests with its outer diameter or its outer side against the inner diameter or the inner side of the hollow shaft stub 3 with a close tolerance. In this way, the base 19 of the knife pin 17 is arranged in a positionally secured manner in two areas in the hollow shaft stub 3, thereby ensuring the alignment of the knife pin 17 along the longitudinal axis 11.

[0109] To ensure the rotationally secure arrangement of the knife pin 17 in the hollow shaft stub 3, at least one second position-locking element 23 is arranged between these two components. In the example of Figure 2, the second position-locking element 23 is designed as a feather key for transmitting force between the hollow shaft stub 3 and the knife pin 17, with two of these second position-locking elements 23 being shown in Figure 2.

[0110] Typically, such second position-locking elements 23 are arranged as keys in corresponding grooves in the hollow shaft stub 3 and in the base 19 of the knife journal 17. These second position-locking elements 23 enable the transmission of the rotary movement from the hollow shaft stub 3 of the driven screw base body 2 to the knife journal 17 and thus to the cutting tools 24, such as knives, arranged on the knife journal 17. These cutting tools 24 are shown only in simplified form in Figure 2 using a dash-dot line. The transfer area 29 is shown in Figure 2 using a dash-dash line.

[0111] To secure the position, i.e., to prevent movement of the screw head 4 relative to the hollow shaft stub 3 and of the knife pin 17 relative to the hollow shaft stub 3, the transport and working screw 1 has a position-securing locking washer 25. This locking washer 25 is firmly connected to the hollow shaft stub 3 by means of corresponding connecting elements. In one embodiment, the locking washer 25 is screwed to the hollow shaft stub 3 by means of several screws; these screws are not shown in Figure 2.

[0112] The locking washer 25 prevents displacement of the screw head 4 and / or the knife pin 17 relative to the screw base body 2 along the longitudinal axis 11.

[0113] Figure 3 shows a transport and working screw 1 according to the invention in a side view, at least partially.

[0114] The transport and processing screw 1 comprises the screw base body 2 with the first screw flight 9 of the screw base body 2 as the receiving profile for the processed material and the screw head 4 with the first screw flight 15 of the screw head 4, which form a thrust pressure area. Furthermore, the transport and processing screw 1 according to the invention comprises the knife pin 17 arranged in the hollow shaft stub 3 (not shown).

[0115] Also visible is the transition point 31 between the first screw flight 9 of the screw base body 2 and the first screw flight 15 of the screw head 4. The task of the first screw flight 9 of the screw base body 2 is to transport the processing material (not shown) from a receiving area of ​​the comminution machine to the screw head 4, while the task of the first screw flight 15 of the screw head 4 is to generate thrust pressure, particularly for the transfer area 29 in front of the cutting tool 24. The position of the transfer area 29 is shown in Figure 3 only by means of an arrow for the sake of clarity.

[0116] Figure 3 shows the transport and working screw 1 after all components have been assembled and secured in position. In this finished form, the transport and working screw 1 is used in the shredding machine, which is not shown in Figure 3.

[0117] The illustration in Figure 3 shows short cutting edges 26 arranged on the circumference of the screw head 4. These short cutting edges 26 are arranged in an area between adjacent side walls 27, for example, of the first screw flight 15 of the screw head 4, and parallel to them. These short cutting edges 26 are intended for pre-cutting the material to be processed during the transport path of the material via the transfer area 29 to the cutting set, in order to reduce the material strength of the material to be processed and facilitate its introduction into the working areas of the knives of the cutting set. The transfer area 29 and the cutting set with the knives are not shown in Figure 3.

[0118] To reduce wear on the first screw flight 15 of the screw head 4 and the short cutting edges 26, these are hardened accordingly. In one embodiment, the surfaces of these elements 15 and / or 26 are coated with a hard metal layer for this purpose. Other methods known from the prior art for producing harder surfaces can also be used.

[0119] Figure 3 also shows a second screw flight 28 of the screw head 4, which is preferably arranged centrally between the side walls 27 of the first screw flight 15 of the screw head 4. This second screw flight 28 has a wedge-shaped intake edge 32 at its beginning. The function of this intake edge 32 is to divide the flow 33 of the processed material into two partial flows 34, which are subsequently transported between the screw flights 15 and 28 to the ends of the screw flights 15 and 28. The two partial flows 34 exit the screw head 4 at the ends of the screw flights 15 and 28 opposite one another or offset by 180 degrees and reach the cutting set with the knives via the transfer area 29 (not shown).

[0120] It is provided that first support surfaces 35 are arranged at the opposite ends of the screw flights 15 and 28, which are offset by 180 degrees. These first support surfaces 35 are characterized in that they have a surface in the shape of a circular ring section, wherein both surfaces lie in an imaginary first plane which is oriented orthogonally to the longitudinal axis 11. These first support surfaces 35 generate a pressure or counterpressure in order to press the material to be processed against the cutting set with the knives. Starting from the first support surfaces 35, a first force effect 36 is created in each case, which is directed parallel to the longitudinal axis 11 in the direction of the cutting set.

[0121] Furthermore, one of two second support surfaces 37 can be seen in Figure 3, since the second support surface 37 is located behind the knife pin 17 due to the perspective view in Figure 3. The second support surfaces 37 are arranged opposite one another at an offset angle 43 of 90 degrees (not shown) to the first support surfaces 35 and at an angle of 180 degrees to one another.

[0122] The surfaces of the second support surfaces 37 are also formed in the shape of a circular ring section, with both surfaces lying in an imaginary second plane oriented orthogonally to the longitudinal axis 11. Thus, the first support surfaces 35 lie in a first plane spaced from the second plane of the second support surfaces 37.

[0123] These second support surfaces 37 also generate pressure or counterpressure to press the material being processed against the cutting set with the knives. A second force 38 is generated from each of the second support surfaces 37, which is directed parallel to the longitudinal axis 11 in the direction of the cutting set.

[0124] The circular ring cutouts of the first support surfaces 35 and the circular ring cutouts of the second support surfaces 37 each have circular arcs 42, which each extend over a center angle 40 not shown in Figure 3. This center angle 40 lies in a range between 10 degrees and 30 degrees and is in particular 20 degrees.

[0125] There is an angle of 90 degrees between each two adjacent support surfaces 35 and 37. In other words, two adjacent support surfaces 35 and 37 are each offset by 90 degrees from each other. This 90-degree offset arrangement also corresponds to the arrangement of four knives in the cutting set. Since the knives in the cutting set are driven by the knife pin 17, the positions or alignments of the four knives relative to the four support surfaces 35 and 37 remain the same.

[0126] Viewed in a direction of movement of the partial streams 34 of the material to be processed, a displacement body 39 is arranged in front of each of the two second support surfaces 37, whereby only one displacement body 39 can be seen in Figure 3. This displacement body 39 has an additional pitch 41, which is greater than the second pitch of the first screw flight 15 of the screw head 4 or the pitch of the second screw flight 28. In the area of ​​the displacement body 39, an additional displacement or directed movement of the partial stream 34 takes place to support the second force effects 38.

[0127] The screw head 4 has a double flight geometry due to the first screw flight 9 and the second screw flight 28. Due to the four support surfaces 35 and 37, which are offset by 90 degrees to one another, the pressure of the material to be processed is built up by the forces 36 and 38 in the direction of the cutting set, also in four areas offset by 90 degrees to one another. According to the invention, a 4-point conveying profile of the material to be processed is created. This 4-point conveying profile enables all four knife chambers located in front of the knives of the cutting set to have the same fill level with the material to be processed and the same pressure conditions. Thus, the partial surfaces of the perforated disk are used almost equally in four areas and integrated into the comminution of the material to be processed, whereby a significant increase in the throughput of the material to be processed during comminution in the comminution machine is achieved.Figure 4 shows the screw head 4 according to the invention with two screw flights 15 and 28 in a side view.

[0128] The first support surfaces 35 are arranged at the ends of the screw flights 15 and 28. Starting from these first support surfaces 35, the first force effects 36 are shown parallel to the longitudinal axis 11. The first support surfaces 35 lie in an imaginary first plane 44 at the end of the screw head 4. The first plane 44 is oriented orthogonally, or at right angles, to the longitudinal axis 11.

[0129] The second support surfaces 37, only one of which can be seen in Figure 4, lie in an imaginary second plane 45, which is also oriented orthogonally to the longitudinal axis 11 and parallel to the first plane 44.

[0130] The first plane 44 is arranged at a distance of H / 8 from the second plane 45, where H is a pitch of the first or second screw flight 15, 28. Such a pitch H describes the distance of a starting point from a target point when this point lies on the outer circumference of the screw flight and the screw is moved through a rotation angle of 360 degrees.

[0131] Figure 4 also shows the displacer body 39. The displacer body 39 has a greater pitch than the associated first or second screw flight 15, 28 and thereby compresses the material to be conveyed (not shown) during transport through the screw flights 15, 28. The displacer body 39 has an additional pitch 41, the angle of which is shown in Figure 4.

[0132] The wedge-shaped displacement body 39 ends with the circular cutout-shaped surface of the second support surface 37. From this, the second force effect 38 arises.

[0133] Figure 5 shows a perspective view of the screw head 4 according to the invention in conjunction with knives of a cutting tool 24, which are arranged on the knife pin 17. Also shown are the first support surfaces 35, arranged opposite one another and offset by 180 degrees. Also visible are the second support surfaces 37, which are also arranged opposite one another and offset by 180 degrees.

[0134] It can also be seen that the surfaces of the first support surfaces 35 and the surfaces of the second support surfaces 37 have a circular cutout shape. The offset of two adjacent support surfaces 35 and 37 is illustrated by way of example in Figure 5 at a location with an offset angle 43 of 90 degrees between a first support surface 35 and a second support surface 27.

[0135] The circular ring cutouts of the first support surfaces 35 and the circular ring cutouts of the second support surfaces 37 each have circular arcs 42, each extending over the center angle 40. This center angle 40 lies in a range between 10 degrees and 30 degrees and is in particular 20 degrees. The vertices of the center angle 40 and the offset angle 43 lie at a common point on the longitudinal axis 11.

[0136] Since the support surfaces 35 and 37, from which the forces 36 and 38 emanate, are fixedly related to the four blades of the cutting tool 24 and do not change their positions relative to one another, this ensures that the material to be processed is fed almost evenly into all four separate spaces in front of the blades, also referred to here as the blade spaces. This provides a four-point conveying profile of the material to be processed, achieving a nearly uniform filling level and pressure conditions in the four blade spaces. Thus, a larger portion of the perforated disc is utilized in the comminution of the material to be processed than is possible with the prior art. List of reference symbols

[0137] 1 transport and working screw

[0138] 2 screw base bodies

[0139] 3 hollow shaft stub

[0140] 4 snail head

[0141] 5 first end of the screw body

[0142] 6 Limitation

[0143] 7 Means for connecting to a drive unit

[0144] 8 second end of the screw body

[0145] 9 first flight of the screw body

[0146] 10 Length of the hollow shaft stub

[0147] 11 Longitudinal axis

[0148] 12 Opening

[0149] 13 depth

[0150] 14 cylindrical base body

[0151] 15 first screw flight of the screw head

[0152] 16 Length of the screw head

[0153] 17 knife tenons

[0154] 18 first position securing element

[0155] 19 Base of the knife pin

[0156] 20 cones

[0157] 21 circumferential ring

[0158] 22 Hole

[0159] 23 second position securing element

[0160] 24 cutting tools

[0161] 25 Lock washer

[0162] 26 short blade

[0163] 27 Side wall of the snail duct

[0164] 28 second screw flight of the screw head transfer area

[0165] Direction

[0166] Transition point

[0167] Feeding edge

[0168] Flow of processed material

[0169] Partial flow of the processed material first support surface first force effect second support surface second force effect

[0170] Displacer

[0171] Center angle additional pitch displacer

[0172] circular arc

[0173] Offset angle first level second level

Claims

Patent claims 1. Transport and working screw (1) for a comminution machine which operates according to a grinder principle and commins animal or vegetable raw materials, wherein the transport and working screw (1) has at least one first screw flight (9) and one knife pin (17), characterized in that the transport and working screw (1) has a screw base body (2) with a hollow shaft stub (3) and the first screw flight (9) of the screw base body (2) and that a separate, removable screw head (4) with a first screw flight (15) of the screw head (4) is arranged on the hollow shaft stub (3).

2. Transport and working screw (1) according to claim 1, characterized in that a separate, removable knife pin (17) is arranged on the hollow shaft stub (3) of the screw base body (2).

3. Transport and working screw (1) according to claim 1 or 2, characterized in that a first position securing element (18) is arranged between the hollow shaft stub (3) and the screw head (4) and / or a second position securing element (23) is arranged between the hollow shaft stub (3) and the knife pin (17).

4. Transport and working screw (1) according to one of claims 1 to 3, characterized in that a locking washer (25) is arranged on the hollow shaft stub (3) of the screw base body (2) to secure the screw head (4) and the knife pin (17) on the hollow shaft stub (3).

5. Transport and working screw (1) according to one of claims 1 to 4, characterized in that a second screw flight (28) with a wedge-shaped feed cutting edge (32) is arranged on the screw head (4) and that a first support surface (35) is arranged at the ends of the first screw flight (15) and the second screw flight (28), wherein the first support surfaces (35) are arranged opposite one another at an angle of 180 degrees.

6. Transport and working screw (1) according to one of claims 1 to 5, characterized in that second support surfaces (37) are arranged on the first screw flight (15) and on the second screw flight (28) at a distance from the first support surfaces (35), wherein the second support surfaces (37) are arranged opposite one another at an offset angle (43) of 90 degrees to the first support surfaces (35) and at an angle of 180 degrees to one another, and that a displacement body (39) is arranged on each second support surface (37).

7. Method for producing a transport and working screw (1), in which the transport and working screw (1) is provided with a first screw flight (9) and a knife pin (17), characterized in that the transport and working screw (1) is provided with a screw base body (2) which has a hollow shaft stub (3) and the first screw flight (9) of the screw base body (2) and that on this hollow shaft stub (3) a separate, removable screw head (4) with a first screw flight (15) of the screw head (4) is provided.

8. Method according to claim 7, characterized in that a separate, removable knife pin (17) is provided on the hollow shaft stub (3).

9. Method according to claim 7 or 8, characterized in that the screw head (4) is secured against rotation relative to the screw base body (2) by means of a first position securing element (18) and / or the knife pin (17) is secured against rotation relative to the screw base body (2) by means of a second position securing element (23).

10. Method according to one of claims 7 to 9, characterized in that the first screw flight (9) of the screw base body (2) is provided with a pitch different from the first screw flight (15) of the screw head (4) and / or that hardened short cutting edges (26) are provided on the screw head (4) in spaces between the first screw flight (15) of the screw head (4).

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