MIXING DEVICE WITH SPLIT MIXING SCREW AND INDEPENDENTLY DRIVEABLE SCREW WINDING SECTIONS

Description

[0001] The invention relates to a mixing device, in particular a feed mixer, comprising a mixing container with a filling opening and a dispensing opening, at least one mixing element arranged in the mixing container and rotatable about an axis of rotation, for example a mixing screw or reel, a drive device for driving the mixing element.

[0002] Such mixing devices are known in a variety of designs as stationary systems, towed feed mixers or self-propelled feed mixers.

[0003] Stationary mixing systems are used primarily for feeding biogas plants with organic material. Feed mixers are used particularly on dairy farms for mixing and distributing silage and other feed. The feed components are drawn from a storage area or reservoir either by a feed extraction device integrated into the mixer or by an external filling device and placed into the mixing container. Depending on the design of the mixing system, the material in the container is mixed into a homogeneous ration by one or more horizontally or vertically arranged augers and then discharged via a discharge device.

[0004] The mixing screws arranged in the mixing container can be positioned horizontally or vertically. Horizontal mixers with one or more horizontally arranged mixing screws and vertical mixers with one or more vertically arranged mixing screws are known, as are so-called paddle or reel mixers.

[0005] From FR 2 335 370 A1, an agricultural trailer is known that can be used both as a feed mixer wagon and as a spreader for applying fertilizer. The trailer has two mixing augers 3 arranged in the base area, which feed the material loaded into the trailer to an agitator located in the front of the trailer. The agitator comprises two rotors 4, which rotate on one side about themselves and on the other side about a central axis located between the two rotors 4. The rotors 4 form a conveying system that feeds the material supplied to the rotors 4 by the mixing augers 3 either to a return auger 14 or to a discharge opening 10. By means of the return auger 14, the mixture can be conveyed back to the rear of the trailer so that it can be picked up again by the mixing augers 3 and conveyed forward towards the agitator.If a further mixing circuit is not required, the load is conveyed out of the trailer through the discharge opening 10.

[0006] From US Patent 3,352,543 A, a device for mixing liquids and slurries is known. The device comprises a substantially funnel-shaped housing with a mixing element arranged therein. The mixing element may include several inert mixing elements which mix liquids or slurries introduced into the housing in the manner of a whisk. This device is unsuitable for mixing solid substances, in particular for mixing structural feed, which consists, for example, substantially of straw, grass, or corn components.

[0007] From DE 103 45 322 A1 a feed mixer wagon is known which includes two vertical mixing augers that can be driven independently of each other.

[0008] From DE 20 2015 001 543 U1, a mixer wagon with a vertical mixing screw is known, which is equipped with a magnet for selecting metal parts contained in the feed. The magnet is arranged in a recess of the screw thread. The mixing screw has a section located upstream of the magnet and another section downstream of the magnet. While the mixing screw is thus divided into two sections, these two sections are not independent of each other, but rather, together with the magnet, form a single mixing device, i.e., a mixing screw with an integrated magnet.

[0009] US Patent 2011 / 121114 A1 discloses a feed mixer wagon with a multi-stage mixing auger. The central auger tube consists of a lower section with a relatively large diameter and an upper section with a relatively small diameter. The auger includes a shaft that is rotatable around a vertical shaft and sets the auger in rotation during operation.

[0010] The known systems require a relatively long mixing time. A long mixing time incurs costs and can damage the feed structure. The object of the invention is to eliminate the described disadvantages, to make mixing more efficient, and at the same time to protect the structure of the feed.

[0011] This problem is solved by a mixing device having the features of claim 1.

[0012] According to the invention, at least one mixing screw comprises a single or multiple divided worm gear with at least two worm gear sections and a drive device with a first individual drive for the first worm gear section and a second individual drive for the second worm gear section, or a drive gear in which the drive elements for both worm gear sections rotate about the same geometric axis, so that the first worm gear section can be driven at a first speed and the second worm gear section at a second speed, either in the same direction or in opposite directions, depending on or independent of the other worm gear section.

[0013] In mixing devices known as prior art, with at least one horizontally or vertically arranged mixing screw, the screw flight is generally attached to a housing or a central tube. During operation, the housing or the central tube is set in rotation, and the mixing screw rotates uniformly around its axis over its entire range of motion.

[0014] In contrast, the mixing device according to the invention has at least one mixing screw divided into at least two screw flight sections and comprises a drive device with a first individual drive for the first screw flight section and a second individual drive for the second screw flight section, or a drive gearbox in which the drive elements for both screw flight sections rotate about the same geometric axis. Thus, the material to be mixed can be mixed with varying intensity in different areas of the mixing screw. This allows the mixing process to be adapted to different materials and to different phases of the mixing process.

[0015] In a vertically arranged mixing screw, for example, the lower screw flight section can be driven at a lower speed and the upper screw flight section at a higher speed. This allows the power requirement and mixing intensity of the two screw flight sections to be individually adjusted. The overall power requirement and mixing intensity can thus be optimized. Since the power requirement and mixing intensity of the mixing screw depend, among other things, on its rotational speed, a lower speed can be preselected in the lower section of the aforementioned vertical screw compared to the upper section, in order to specifically reduce the power requirement in this area. A higher speed can be selected in the upper section to specifically increase the mixing intensity there.

[0016] As a result, the division of the mixing screw into individually driveable screw winding sections in vertical mixing screws allows the mixing screw as a whole to be adapted to the respective needs and operating conditions.

[0017] In a first embodiment, the first worm gear section and the second worm gear section can be driven in the same direction, either clockwise or counterclockwise.

[0018] With a co-rotating drive, the function and operation of a vertical screw conveyor known from the prior art can be realized. This is achieved by positioning the two screw flight sections in a way that corresponds to the position of a single-piece, prior-art mixing screw conveyor. For this purpose, in a split vertical screw conveyor, the upper end of the first (lower) screw flight section is positioned adjacent to the lower end of the second (upper) screw flight section. This results in a low-resistance transition from one screw flight section to the other. If both screw flight sections are driven at the same speed in this position, the material to be mixed is conveyed from bottom to top through the adjacent screw flight sections, analogous to a prior-art mixing screw conveyor with a continuous screw flight.In contrast to conventional mixing screws, the mixing screw according to the invention makes it possible to drive the two screw flight sections in the same direction but at different speeds. This allows the mixing effect and power requirement to be varied according to requirements.

[0019] As an alternative to a co-rotating drive, a counter-rotating drive can also be used. With such a drive, one screw section rotates clockwise and the other counter-clockwise. A mixing device with counter-rotating screw sections has a particularly intensive mixing effect and is therefore especially well-suited for applications where a short mixing time is required. It is also important to note that, because the mixing rotation is counter-clockwise, very intensive (almost forced) mixing can be expected, particularly in the "collision zone" of the material being mixed.

[0020] In a particular embodiment, the rotational speed of the first and / or the second screw flight section can be adjustable. This adjustment can be achieved, for example, by means of an additional, preferably continuously variable, gearbox. The speed setting allows for adjustment of the rotational speed during a mixing process. For instance, in the initial phase of a mixing process, when the material is still largely uncut, a lower rotational speed can be preselected for one or both screw flight sections to reduce the power requirement. With the material already cut and / or during the application of the mixture, a higher or increasing rotational speed can be selected to accelerate the mixing or application process.

[0021] A variable speed can also be used to adapt the mixing process to varying boundary conditions. These conditions might include, for example, the instantaneous weight of the material being mixed, the instantaneous power requirement, or the instantaneous fill level of the mixing container. These instantaneous boundary conditions can be measured using suitable sensors. For instance, the weight of the material in the mixing container can be measured with standard weighing sensors, the power requirement of the drive components can be determined by measuring the torque in the drive train, or the fill level of the mixing container can be determined with optical sensors (camera, light barrier). Based on the measured sensor data, the speed of one or both screw flight sections can then be adjusted as needed.

[0022] The mixing screw can comprise a tubular housing with a first housing section and a second housing section, wherein the first worm gear section is mounted on the first housing section and the second worm gear section is mounted on the second housing section and at least one single drive is arranged inside the housing.

[0023] Within the tubular housing, which may be conical in its initial section, the drive unit and its individual drives are both well protected against damage and housed in a space-saving manner. In a vertical screw according to the invention with a frustoconical housing in the inner region of the lower screw flight section, the drive device can thus preferably be housed entirely or partially within the aforementioned frustoconical housing.

[0024] The drive mechanism of the mixing device preferably comprises a planetary gear set. Planetary gear sets, also called epicyclic gear sets, are gear or friction gear sets that, in addition to shafts fixed to the frame, also have axles that rotate on circular paths within the frame. Accordingly, a distinction is made between the central or sun gears mounted on the fixed axles and the epicyclic or planet gears mounted on the rotating axles. The gears rotating on the rotating axles orbit a central gear, similar to how planets orbit the sun. The carrier that supports the rotating axles itself rotates around a fixed axle.

[0025] The use of a planetary gear in the mixing device according to the invention has the following advantages in particular: The design is small and compact, resulting in low weight and favorable space efficiency relative to the rated torque. High efficiency is achieved through small inertial masses and low rolling and sliding speeds on the tooth flanks. A planetary gearbox offers high overload reserves, which is particularly advantageous during the start-up of mixed operation. The input and output shafts are coaxial. Reversing the direction of rotation is possible.

[0026] In a preferred embodiment, the planetary gear comprises a carrier, a ring gear, and a sun gear, wherein either the carrier, the ring gear, or the sun gear is fixed, and the two non-fixed units each provide an individual drive for the first and second worm gear sections. The planetary gear thus operates in two-shaft mode. Therefore, the gear is positively driven and has a degree of friction of F=1.

[0027] In a preferred embodiment, the screw flight sections are separated from each other by a parting plane, with the first screw flight section being arranged on one side of the parting plane and the second screw flight section on the other side of the parting plane. This prevents collisions between the screw flight sections even if the two screw flight sections are driven at different rotational speeds or different speeds.

[0028] Preferably, the separating plane located between the screw flight sections is arranged at a 90° angle to the axis of rotation of the mixing screw. This results in a simple design of the screw flight sections and particularly cost-effective manufacturing. The separation at a 90° angle to the axis of rotation is easy to set and readjust due to the precise adjustment required along the entire length of the meeting area.

[0029] In a vertical screw conveyor, an alternative design allows for the separation plane to be inclined instead of being angled at 90° to the axis of rotation. For example, inclined screw flight segments relative to the axis of rotation enhance the concentric conveying effect. With inwardly inclined screw flight segments in a vertical screw conveyor, less material falls off the mixing screw when the drum rotates.

[0030] The individual drives of the screw flight sections can be mounted together on one side of the parting line. This has the advantage of creating corresponding free spaces on the other side of the parting line. In the case of a vertical screw conveyor, this results in a freely accessible space above the mixing screw and easy filling of the mixing chamber from above.

[0031] Alternatively, it is also possible to arrange the individual drive of the first screw flight section on the first side of the parting line and the individual drive of the second screw flight section on the second side of the parting line. This allows the mixing screw to be supported equally well from both sides.

[0032] In a preferred embodiment, the first and / or the second screw flight section has an end section extending from the second side to the parting line. The end section may have a cutting edge or a non-cutting area with blunt elements. The blunt elements can form a transition zone, which may be configured as line contact (parallel) or point contact (V-shaped). A particularly suitable application would be, for example, the preparation of free-flowing mixed rations where no cutting tools are required.

[0033] As an alternative to a non-cutting end section, a cutting edge can be provided on at least one screw flight section to cut the mixture. Preferably, however, not only one screw flight section has a cutting edge, but both screw flight sections have a cutting edge. The two cutting edges form counter-edges against each other, by means of which the mixture can be cut with minimal resistance.

[0034] The cutting edges can be arranged so that they contact each other at the moment of contact when the worm gear sections rotate at different speeds. The contact can be linear or non-linear, for example, wave-like. A non-linear contact requires less force and thus reduces the drive requirement.

[0035] Furthermore, the cutting edges can be adjustable in height and / or orientation. To achieve this adjustability, a screw connection can be provided, for example, with elongated holes for the screws.

[0036] Preferably, the cutting edges form a V-shaped formation at the moment they meet. As the rotation continues, the material between the cutting edges is thus separated by a shearing cut. This avoids power peaks and results in a smooth cut in the area of ​​the cutting edges, which is gentle on the internal structure of the mixture. In simpler terms, the mixture is cut by a pulling, scissor-like motion without being torn or crushed.

[0037] One or both cutting edges can be linear. If both cutting edges are linear, the cutting angle between them is constant along their entire length. With linear cutting edges on both sides, both the cutting angle and the cutting force remain constant.

[0038] Opposite the cutting edge, a flywheel can be provided. Using such a flywheel, as is known, for example, from the crankshaft / flywheel system in an engine, the reaction force can be better / more compactly balanced.

[0039] Furthermore, it is possible for one or both cutting edges to have a curved, saber-like contour. This saber-like contour enhances the pulling effect of the cutting edge between the cutting and counter-cutting edges. A saber-shaped cutting edge also has the advantage of distributing the reaction force over a larger area (angle of rotation) and thus more effectively across the mixing auger. This results in a more uniform torque and reduces wear on the drive train.

[0040] Furthermore, a curved cutting edge is generally longer than a straight cutting edge, so that by using a longer cutting edge the cutting work can be better distributed over the entire cutting edge.

[0041] With counter-rotating blades, the saber-shaped transition at the cutting edge results in only point contact in the overlap area (starting at the bottom / inside, ending at the top / outside). Blockages caused by clogging material are reduced because the material flow can be divided. This also reduces the risk of the mixture becoming compacted and / or mushy. This is particularly important when the mixture is feed for cattle or ruminants. Maintaining the feed structure promotes the metabolism and health of these animals.

[0042] In a further embodiment, an extension penetrating the parting line can be connected to at least one of the screw flight sections. This creates an overlap zone between the screw flight sections in the axial direction of the screw. The overlap zone is thus a space in the axial direction of the screw in which both screw flight sections are active. To prevent collisions between the screw flight sections at different rotational speeds, the end of one screw flight section can be arranged so that, viewed radially, it is located in an inner region and the end of the other screw flight section is located in an outer region. The extension penetrating the parting line between the screw flight sections then winds around an inner region of the other screw flight section in a corkscrew-like fashion.

[0043] Alternatively, it is also possible that the aforementioned extension of one screw winding section does not radially extend beyond the other screw winding section, but is guided through a corresponding recess in the other screw winding section during the rotational movement in order to avoid a collision in this way.

[0044] Regardless of how the risk of collision is addressed, the overlapping area of ​​the two screw flight sections results in an intensified mixing effect. This is generally the case, in particular, when the lower screw flight section with the larger effective diameter, i.e., the lower outer screw part, has a (slight) pitch pointing inwards towards the central axis of rotation of the screw, and the screw flight section of the inner screw part has a (even slightly) outwards pitch.

[0045] To accelerate the comminution of the material, one or more cutting tools can be attached to one or both sections of the screw flight. These cutting tools, for example, cutting blades, can operate as free-cutting tools. Preferably, however, the cutting tools work in conjunction with counter blades attached to the opposite screw flight section. As the screw flight sections rotate, the cutting tools are guided past the counter blades. This results in a shearing cut that severs the material located between the cutting tool and the counter blade.

[0046] Further measures improving the invention are described in more detail below with reference to the figures and preferred embodiments of the invention.

[0047] The figures show: Fig. 1 shows a feed mixer wagon with two vertical augers in a perspective side view; Fig. 2 shows a feed mixer wagon with a feed discharge device in a side view with an indicated horizontal auger; Fig. 3 shows a vertical auger in a first embodiment with co-rotating drive and a linear transition between the auger flight sections in a perspective view; Fig. 4 shows the vertical auger according to Fig. 3 in a side view; Fig. 5 shows the vertical screw according to the Figures 3 and 4 in a cutaway side view; Fig. 6 shows a vertical screw in a second embodiment with counter-rotating drive and a linear transition between the screw thread sections in a perspective view; Fig. 7 shows the vertical screw according to Fig. 6 in a side view; Fig. 8 shows the vertical screw according to the Figures 6 and 7in a cutaway side view; Fig. 9 shows a vertical screw in a third embodiment with co-rotating drive and curved transition between the screw thread sections in a perspective view; Fig. 10 shows the vertical screw according to Fig. 9 in a side view; Fig. 11 shows a vertical screw in a fourth embodiment with counter-rotating drive and an overlap area between the screw thread sections in a perspective view; Fig. 12 shows the vertical screw according to Fig. 11 in a first side view; Fig. 13 shows the vertical screw according to Fig. 11 in a second side view; Fig. 14 shows a vertical screw in a fifth embodiment with counter-rotating drive and additional cutting tools on the screw flight sections in a perspective view; Fig. 15 shows the vertical screw according to Fig. 14in a first side view; Fig. 16 shows the vertical screw according to Fig. 14 in a second side view.

[0048] Identical or similar elements in the following figures may be designated with the same or similar reference numerals. Furthermore, the figures of the drawing, their description, and the claims contain numerous features in combination. It is clear to a person skilled in the art that these features can also be considered individually or combined into further combinations not described in detail here. The invention expressly extends to embodiments that are not defined by combinations of features from explicit cross-references in the claims, meaning that the disclosed features of the invention can be combined with one another in any way that is technically feasible. The exemplary embodiments shown in the figures are therefore merely descriptive and are not intended to limit the invention in any way.

[0049] The terms used below, "upper", "top", "lower", "left" or "right", refer to the arrangement of the components of the mixing device in operating mode as shown in the drawing.

[0050] Figure 1 Figure 1 shows a mixing device 100 in the form of a feed mixer wagon with a mixing container 10 and a mixing element 13 arranged therein in the form of two vertical mixing augers 15. The feed mixer wagon has a chassis 20 and can be coupled to a towing vehicle, for example a tractor (not shown), by means of a hitch 39. The mixing container 10 is open at the top, so that feed components to be mixed can be added to the mixing container 10 from above through a filling opening 11 formed therein. The feed components introduced into the mixing container 10 are mixed by the mixing augers 15 to form a homogeneous feed mixture and can then be dispensed through a discharge opening 12.

[0051] The wall of the mixing container 10 is shown interrupted, so that of the two mixing augers 15 configured identically in the illustrated embodiment, the rear mixing auger 15, viewed in the direction of travel of the feed mixer wagon, can be clearly seen.

[0052] Both mixing screws 15 have a screw flight 16 with a lower screw flight section S1 and an upper screw flight section S2 arranged in the opposite direction. The two screw flight sections S1 and S2 can be driven independently of each other by means of a drive device 17 with two individual drives 18 and 19. This screw design corresponds to that described in the Figures 4 to 6 the structure shown and is related to the explanation of the Figures 4 to 6 described in more detail. In addition to the screw flight 16, a scraping arm 37 can be installed in the lower area of ​​the mixing screw 15 (see below). Fig. 3) is designed to accelerate the emptying of residual feed during dispensing through the dispensing opening 12. The screw thread sections S1 and S2, which can be driven independently and at different speeds n1 and n2, ensure intensive and rapid mixing of the feed components.

[0053] Fig. 2 Figure 1 shows a mixing device 100' in the form of a feed mixer wagon with a mixing container 10 and a mixing element 13 arranged therein in the form of a horizontal mixing screw 15. The feed mixer wagon is filled either by means of a feed removal device 36 or through a removal opening 11 provided on the top of the mixing container 10'. The mixing screw 15 comprises a front screw tube 40 with a screw flight S1 arranged thereon and a rear screw tube 41 with a screw flight S2 arranged thereon.

[0054] The in Figure 2The illustrated embodiment of the mixing device 100' is to be understood as exemplary and is not claimed by this patent.

[0055] The Figures 3, 4 and 5 Figure 1 shows a vertical screw conveyor 15 in a first embodiment with a co-rotating drive and a linear transition between the screw flight sections S1 and S2. The lower screw flight section S1, like the upper screw flight section S2, rotates in a clockwise direction R1. Both screw flight sections S1 and S2 convey the mixture upwards when rotating in the direction R1.

[0056] To illustrate that the rotational speeds n1 and n2 can be different, two arrows are drawn in the region of rotational speed n2, while only one arrow is drawn in the region of rotational speed n1. The worm gear section S1 lies entirely on a first side 24 of the parting plane 23, while the worm gear section S2 lies entirely on a second side 25 of the parting plane 23. Collisions of the worm gear sections S1 and S2 during rotation at different rotational speeds n1 and n2 are therefore prevented.

[0057] The lower screw flight S1 comprises an end section 26 on its upper side with a linear cutting edge 27 in the illustrated embodiment. The upper screw flight S2 comprises an end section 28 on its lower side with a linear cutting edge 29 in the illustrated embodiment. The cutting edges 27 and 29 are adjustable relative to each other in the illustrated embodiment. This allows adjustment of the cutting gap between the cutting edges and also of the alignment of the cutting edges. In the illustrated embodiment, the cutting edges 27 and 29 are adjusted relative to each other such that a V-shaped formation 30 is formed when the cutting edges 27 and 29 overlap. Material located between the cutting edges is thus cut with minimal resistance.

[0058] The worm gear sections S1 and S2 are driven by a drive device 17 that partially projects into a housing 21 from below. The housing 21 comprises two separate housing sections G1 and G2. The worm gear section S1 is mounted on the housing section G1, which is conically shaped in the illustrated embodiment, and the worm gear section S2 is mounted on the housing section G2. The drive device 17 comprises a planetary gear set 22 with a sun gear 42, planet gears 44 mounted on planet carriers 43, and a ring gear 45. The in Fig. 5In the illustrated embodiment, the worm gear sections S1 and S2 are driven in the same direction by coupling the planet carriers 43 to the lower housing section G1 and the sun gear 42 to the upper housing section G2. In a simple embodiment, the rotational speeds n1 and n2 can be predefined by the design of the planetary gear. In the illustrated embodiment, the planetary gear 22 includes an additional ring gear 46. This results in a superposition function in which the ring gear 46 of the first planetary stage does not form a fixed unit with the main body, but is toothed with a correction worm shaft or via external teeth. By rotating this worm or via a pinion drive (for example, by means of a hydraulic motor), the ring gear of the planetary gear rotates and the output speed changes.Superimposed gearboxes are the ideal solution for synchronizing the processing phases when mixing animal feed. In principle, it would also be possible to incorporate a further superimposed function on the second planetary stage. In such an embodiment, the speeds n1 and n2 can be adjusted independently of each other.

[0059] The Figures 6, 7 and 8 Figure 15 shows a vertical screw conveyor 15 in a second embodiment with a counter-rotating drive and a linear transition between the screw flight sections S1 and S2. The lower screw flight section S1 rotates in the direction of rotation R1, while the upper screw flight section S2 rotates counterclockwise in the direction of rotation R2. The screw flight sections S1 and S2 are configured such that they convey the mixture upwards despite the different directions of rotation R1 and R2.

[0060] Analogous to the first embodiment according to the Figures 3 to 5also includes the second embodiment according to the Figures 6 to 8 A drive device 17 with a planetary gear 22. In contrast to the first embodiment, the second embodiment features a counter-rotating drive of the worm gear sections S1 and S2. For this purpose, the lower housing section G1 – and thus also the drive of the worm gear section S1 – is driven via the ring gear 45. The upper housing section G2 – and thus also the drive of the worm gear section S2 – is driven, as in the first embodiment, via the sun gear 42. In the second embodiment as well, the rotational speeds n1 and n2 are variable and can be implemented, for example, in the manner already described above.

[0061] The Figures 9 and 10Figure 1 shows a vertical mixing screw 15 in a third embodiment with a co-rotating drive. The end sections 26 and 28 of the screw flight sections S1 and S2 each have a saber-shaped curved contour 31. The outer region of the screw flight section S1 is coreless and projects a short distance beyond the parting line 23 into the region of the second side 25. This results in an overlap between the screw flight regions S1 and S2, the effect of which is described in the section on the Figures 11 to 13 is explained in more detail.

[0062] Alternatively, the parting plane 23 could also be arranged at an angle and oriented to the alignment of the saber-shaped curved contour 31. In such a configuration, the worm gear section S1 would lie entirely on the first side 24 of the parting plane 23, and the worm gear section S2 entirely on the second side 25.

[0063] In the Figures 9 and 10as well as in the following described Figures 11 to 16 The respective drive devices 17 are not shown. The ones in the Figures 9 to 16 The vertical mixing screws 15 shown are preferably also driven by planetary gears 22. In this respect, the provisions regarding the first and second embodiments apply ( Figures 3 to 6 as well as the explanations given in sections 7 to 9). In simplified terms, all embodiments can be equipped with a co-rotating or a counter-rotating drive.

[0064] The Figures 11 to 13Figure 15 shows a vertical mixing screw in a fourth embodiment with a counter-rotating drive. In contrast to embodiments one to three, the screw flight section S1 breaks through the parting plane 23 and projects with an extension 32 into the area of ​​the second side 25. To prevent a collision when the screw flight sections S1 and S2 rotate at different speeds n1 and n2, the extension 32 is coreless and projects laterally beyond the screw flight section S2. The extension 32 thus creates an overlap area 33 in the vertical direction. Within this overlap area 33, the screw flight section S2 acts in an inner region located close to the center of the axis of rotation 14, and the extension 32 of the screw flight section S1 acts in an outer region located farther from the center of the axis of rotation 14.

[0065] Analogous to the described embodiment, it would also be possible, in principle, for an extension provided on the worm gear section S2 to project into an area on the first side 24 of the parting plane 23 or for a mutual overlap to occur. The coreless extensions must be designed in such a way that collisions are prevented when the worm gear sections S1 and S2 rotate at different speeds n1 and n2.

[0066] Regardless of how the overlap area is designed, the overlap of the screw thread sections S1 and S2 results in a particularly intensive and rapid mixing of the feed components.

[0067] The Figures 14 to 16Figure 1 shows a vertical mixing screw 15 in a fifth embodiment. This fifth embodiment has a counter-rotating drive and additional cutting tools 34 in the form of cutting blades. In the illustrated embodiment, five cutting blades are mounted vertically on the screw flight section S1 in the region of the end section 26. The cutting tools 34 work together with counter blades 35, which are formed by slots 38 that are provided in the end section 28 of the screw flight section S2. The additional cutting tools 34 and counter blades 35 cut the feed located in the transition area between the screw flight sections S1 and S2, thus helping to reduce the risk of mushy feeding and to maintain the structure of the feed.Furthermore, they reduce the risk of feed becoming trapped between the screw spiral sections and unacceptably high load peaks occurring due to the overlapping of the end sections 26 and 28.

[0068] The five described examples represent only a few of the many possible variations. In particular, all technically feasible combinations of the following variants are possible: different drive types (co-rotating, counter-rotating) with different drive devices (planetary gears, individual drives), different designs of the worm gear sections S1 and S2 (with overlap area, without overlap area), different designs of the end sections 26 and 28 or of the cutting edges 27 and 29 (linear, curved, serrated, etc.), different types and attachment of additional cutting tools 34 and counter blades 35.

[0069] All embodiments according to the invention have in common that a mixing element 13 comprises at least two worm gear sections S1 and S2, each of which can be driven individually. Reference symbol list

[0070] 10 Mixing container 10' Mixing container 11 Filling opening 12 Dispensing opening 13 Mixing element 14 Rotary axis (of 13 or15) 15Mixing screw 16Screw flight 17Drive device 18First single drive 19Second single drive 20Chassis 21Housing 22Planetary gearbox 23Separating plane 24First side (of 23) 25Second side (of 23) 26End section (of S1) 27Cutting edge (at 26) 28End section (of S2) 29Cutting edge (at 28) 30V-shaped formation 31Curved contour 32Extension (at S1 and / or S2) 33Overlap area (of S1 and S2) 34Cutting tool 35Counter blade 36Removal device 37Clearing arm 38Slot (in 28) 39Attachment device 40Screw tube 41Screw tube 42Sun wheel 43 Planetary carrier 44 Planetary gears 45 Ring gear (Planetary stage 2) 46 Ring gear (Planetary stage 1) 100 Mixing device (Vertical mixer) 100' Mixing device (Horizontal mixer) G1 Housing section G2 Housing section n1 Speed ​​(of S1) n2 Speed ​​(of S2) S1 First worm gear section S2 Second worm gear section R1 Direction of rotation (clockwise) R2 Direction of rotation (counterclockwise).

Claims

1. Mixing device (100), in particular feed mixer, comprising - a mixing container (10) with a filling opening (11) and an outlet opening (12) - at least one mixing organ (13) arranged in the mixing container (10) and rotatable about a vertical axis of rotation (14), such as a mixing screw (15), - a drive unit (17) for driving the mixing organ (13) characterised in that at least one mixing organ (13) - comprises a single or multiple divided screw winding (16) with at least two screw winding sections (S1, S2) and - the drive unit (17) comprises a first individual drive (18) for the first screw winding section (S1) and a second individual drive (19) for the second screw winding section (S2) or a drive gear in which the drive elements for both screw winding sections (S1, S2) rotate about the same geometric vehicle axle, so that the first screw winding section (S1) can be driven at a first speed of rotation (n1) and the second screw winding section (S2) can be driven at a second speed of rotation (n2) in a dependent or independent manner relative to the other screw winding section (S1, S2), either in the same direction or in opposite directions.

2. Mixing device (100) according to claim 1, characterised in that the first screw winding section (S1) and the second screw winding section (S2) can be driven in the same direction of rotation (R1) or in opposite directions of rotation (R2).

3. Mixing device (100) according to claim 1, characterised in that: - the first screw winding section (S1) in the direction of rotation (R1) and the second screw winding section (S2) in the direction of rotation (R2) - or vice versa, the first screw winding section (S1) in the direction of rotation (R2) and the second screw winding section (S2) in the direction of rotation (R1) can be driven in opposite directions.

4. Mixing device (100) according to one of claims 1 to 3, characterised in that the speed of rotation (n1) of the first screw winding section (S1) and / or the speed of rotation (n2) of the second screw winding section (S2) are adjustable.

5. Mixing device (100) according to one of claims 1 to 4, characterised in that the mixing organ (13) - comprises a tubular housing (21) with a first housing section (G1) and a second housing section (G2), - the first screw winding section (S1) is mounted on the first housing section (G1) and the second screw winding section (S2) is mounted on the second housing section (G2), and - the drive unit (17) is arranged at least partially within the housing (21).

6. Mixing device (100) according to any of claims 1 to 5, characterised in that the drive unit (17) comprises at least one planetary gear (22).

7. Mixing device (100) according to claim 6, characterised in that the planetary gear (22) comprises a web, a ring gear and a sun gear, and either the web or the ring gear or the sun gear is fixed and the two non-fixed units each form an individual drive for the first and second screw winding sections (S1, S2).

8. Mixing device (100) according to one of claims 1 to 7, characterised in that the screw winding sections (S1, S2) are separated from each other by a separation level (23) and the first screw winding section (S1) is arranged on a first side (24) of the separation level (23) and the second screw winding section (S2) is arranged on the second side (25) of the separation level (23).

9. Mixing device (100) according to claim 8, characterised in that the separation level (23) is arranged at an angle of 90° to the axis of rotation (14) of the mixing organ (13).

10. Mixing device (100) according to one of claims 8 or 9, characterised in that the individual drive (18) of the first screw winding section (S1) is arranged on the first side (24) of the separation level (23) and the individual drive (19) of the second screw winding section (S2) is arranged on the second side (25) of the separation level (23).

11. Mixing device (100) according to one of claims 8 to 10, characterised in that - the first screw winding section (S1) has an end section (26) extending from the first side (24) to the separation level (23) with a cutting edge (27) and / or - the second screw winding section (S2) has an end section (28) extending from the second side (25) to the separation level (23) and having a cutting edge (29).

12. Mixing device (100) according to claim 11, characterised in that the cutting edges (27, 29) form a V-shaped formation (30) with different rotational speeds (n1, n2) when the screw winding sections (S1, S2) at different speeds of rotation (n1, n2) form a V-shaped formation (30) when they meet, so that when the rotational movement continues, material located between the cutting edges (27, 29) is separated by a shear cut.

13. Mixing device (100) according to claim 11 or 12, characterised in that one or both cutting edges (27, 29) are linear or have a curved, sabre-like contour (31).

14. Mixing device (100) according to one of claims 8 to 13, characterised in that at least one of the screw winding sections (S1, S2) is connected to an extension (32) which breaks through the separation level (23), so that an overlap area (33) is formed between the screw winding sections (S1, S2).

15. Mixing device (100) according to one of claims 1 to 14, characterised in that cutting tools (34) are attached to one screw winding section (S1) or (S2) and counter blades (35) are attached to the other screw winding section (S1) or (S2), which, when the screw winding sections (S1, S2) rotate at different speeds of rotation (n1, n2), can pass each other in a shearing manner, so that material located between the cutting tool (34) and the counter blade (35) is cut.