Agricultural singulation device for singulating granular material

Abstract

The invention relates to an agricultural singulation device (5) for singulating granular material, in particular seeds and / or fertiliser. In illustrative embodiments, the singulation device (5) comprises: a housing having a shaft (W) which is rotatably mounted inside the housing and defines an axis of rotation (D); and a singulating element (7) that is accommodated in an interior space defined in the housing. The singulating element (7) is coupled to the shaft (W) so that the singulating element (7) is rotatably mounted relative to the housing. Furthermore, the singulating element (7) is positioned in the housing in such a way that a first region and a second region are defined in the housing, and a pressure difference can be generated between these regions in order to cause granular material to accumulate in the first region against the singulating element. The singulation device (5) also comprises, in the second region, a labyrinth seal (20) that is formed by a first sealing portion (22) formed on a periphery of the singulating element (7) and a second sealing portion (24) on one or more inner walls of the housing such that the first sealing portion (22) and the second sealing portion (24) are interlocking structures without mechanical contact.

Description

[0001] Agricultural singling device for singling granular material

[0002] The invention relates to an agricultural singling device for singling granular material according to the preamble of patent claim 1.

[0003] In order to optimize yield and costs on the farm, it is of great importance for a farmer to sow seeds on agricultural land with the greatest possible accuracy in terms of the amount sown and the spatial distribution of the sown seeds. A variety of agricultural devices are known for this purpose, for example as towed and / or mounted implements. Such implements include, among others, agricultural seed drills, which are used to distribute granular material, in particular seed and / or fertilizer, onto agricultural land. For this purpose, such seed drills comprise, in addition to at least one storage container suitable for holding the granular material, at least one, in particular pneumatic, conveying device for supplying the granular material to at least one singulating device arranged on the seed drill.In other embodiments, the granular material can alternatively or additionally be fed from the storage container to the singulating device by gravity. The singulating device is configured to at least partially singulate the supplied granular material and, depending on the type of granular material, in particular seed and / or fertilizer, to discharge it toward the agricultural land as needed.

[0004] Depending on the type or variety, the granular material must be distributed along the cultivated area at different seeding rates and spacings. To meet this need with generic singling devices, various solutions are known from the prior art, such as conventional precision seed drills, which are described in each of the documents DE 10 2007 062 968 A1, EP 0 329 095 A1, EP 2 375 880 A1, and EP 3 735 814 A1.

[0005] Typically, a known precision seed drill has a singling device for singulating seeds, which is arranged in a housing. The singling device comprises a singling element made of plastic and driven in rotation by a shaft, and a turntable that is in sliding mechanical contact with the singling element. The turntable and the singling disc are not rigidly connected to one another. When the singling disc rotates, the turntable is also set in rotation by the mechanical contact with the singling disc and is driven along in the rotation, so that in this sense the mechanical contact between the singling disc and the turntable provides a "sliding seal."

[0006] In the known singling device, the interior of the housing is divided into two regions by the singling element in such a way that a pressure difference can be generated between a first region and a second region in the housing by means of a fan. Typically, the singling element has suitable through-openings at regular intervals along its circumferential direction and / or in its outer region near the circumferential line for carrying along individual grains of the granular material. The through-openings create spatial connections between the first and second regions of the housing. The grains accumulate at these through-openings due to the pressure difference. In addition, the singling device has a cover element at a suitable location which, by temporarily covering the through-openings, prevents the pressure difference and thus a continuous accumulation of the transported grains at the through-openings.

[0007] There is a continuing need to optimise the accuracy of seed and / or fertiliser application in seed drills without complicated design and with low wear, long service life and maintenance-free seed drills with a good cost-benefit ratio.

[0008] This object is achieved by an agricultural singling device for singling granular material according to claim 1. Further advantageous embodiments of the invention are defined in the dependent claims.

[0009] According to a first aspect of the invention, an agricultural singling device for singling granular material, in particular seed and / or fertilizer, is provided. According to illustrative embodiments, the singling device in this aspect comprises a housing with a shaft rotatably mounted in the interior of the housing, which shaft defines a rotation axis, a bell element, and a singling element received in the housing and coupled to the shaft in the interior, such that the singling element is rotatably mounted relative to the housing, and has a plurality of through-openings extending through the singling element. The singling element is arranged in the housing such that the interior of the housing is divided into a first housing region as an overpressure region during operation of the singling element and a second housing region as a negative pressure region during operation of the singling element.A pressure difference can be generated between the first region and the second region for the deposition of granular material on the separating element in the first region compared to the second region. The separating device further comprises a labyrinth seal in the second region, which is formed by a first sealing section on a periphery of the separating element and a second sealing section on one or more inner walls of the housing such that the first sealing section and the second sealing section are interlocking structures without mechanical contact.

[0010] In a second aspect of the invention, an agricultural singling device for singling granular material, in particular seed and / or fertilizer, is provided, wherein the singling device comprises a housing with a housing assembly and a cover assembly detachably mounted on the housing assembly, and a singling element which is accommodated in an interior space defined in the housing. The housing assembly or the cover assembly has a rotatably mounted shaft (which defines a rotation axis), and the singling element is coupled to the shaft, such that the singling element is rotatably mounted relative to the housing. Furthermore, the singling element is arranged in the housing such that a first region is defined between the singling element and the housing assembly.Furthermore, the separating element is arranged in the housing such that a second region is defined between the separating element and the cover assembly, wherein a pressure difference can be generated between these regions for the deposition of granular material on the separating element. The separating device further comprises a labyrinth seal formed by a first sealing section on a periphery of the separating element and a second sealing section on the cover assembly such that the first sealing section and the second sealing section are interlocking structures without mechanical contact.

[0011] A corresponding separating device according to the first and second aspects of the invention features a simplified structure, since elements such as a turntable are omitted, and offers an advantageous service life and freedom from maintenance by eliminating abrasive components and, in particular, abrasive seals. Thus, a corresponding separating device represents a cost-effective device.

[0012] In illustrative embodiments of the various aspects of the invention, an agricultural singling device for singling granular material, in particular seed and / or fertilizer, is provided. As described above, the singling device may comprise a housing with a housing assembly having a rotatably mounted shaft defining a rotation axis, and a cover assembly detachably mounted on the housing assembly. Furthermore, the singling device comprises a singling element accommodated in an interior space defined in the housing. The singling element is coupled to the shaft such that the singling element is rotatably mounted relative to the housing. Thus, the shaft and the singling element are rotatable, while the housing and its elements are stationary.

[0013] Furthermore, in the second aspect, as described above, the separating element can be arranged in the housing such that a first region is defined between the separating element and the housing assembly, and a second region is defined between the separating element and the cover assembly. For example, the cover assembly can comprise a housing cover that, together with the housing assembly, defines the interior of the housing, wherein the second region is defined between the housing cover and the separating element.

[0014] In the various aspects of the invention, as described above, a pressure difference can be generated in the interior of the housing between the first region and the second region by means of a pressure reservoir. A pressure reservoir can provide an overpressure or a negative pressure. For example, a pressure reservoir can be implemented by a blower or a suction device, by means of a container with a pressurized fluid, by means of a pump, etc. Advantageously, a greater pressure is applied on a seed side of the singling element (i.e. the side of the singling element to which seed is fed during operation) than on a side of the singling element opposite the seed side, such that seeds are moved to bores in the singling element and adhere there due to the pressure difference.

[0015] In the various aspects of the invention, the separating element has a radial row of through-openings, for example, through-openings arranged at regular intervals in the radial row, for entraining individual grains of the granular material. The through-openings create spatial connections between the first region and the second region of the housing, and due to the pressure difference, the grains accumulate at these through-openings.

[0016] In this way, the singulation quality can be advantageously optimized by changing the pressure difference for different geometries of the seed to be sown, and singulation of the grains by means of pressure difference during operation can be safer / less sensitive to different grain geometries than mechanical singulation via volume, such as by means of spoons and / or pockets.

[0017] A radial row refers to a series of through holes with a constant radius extending from a center point of the singulating element, such as the point where a rotational axis defined by the shaft passes through the singulating element. Additional radial rows with different radii and optionally different through hole sizes and / or spacing can be provided. This allows the singulating element to be used to spread a larger quantity of seed or seeds of different grain sizes. Pressure control can also be adjusted using through holes.

[0018] In illustrative examples herein, the separating element can have suitable through-openings at regular intervals along its circumferential direction, i.e., in the azimuthal direction, in the separating element and / or in its outer region near the circumferential line. The through-openings can create spatial connections between the first region and the second region of the housing, and the grains can accumulate at these through-openings due to the pressure difference.

[0019] Furthermore, in the various aspects of the invention, as described above, the separating device further comprises a labyrinth seal formed by a first sealing portion on a periphery of the separating element and a second sealing portion on one or more interior walls of the housing, for example, on the cover assembly in the interior of the housing, such that the first sealing portion and the second sealing portion are interlocking structures without mechanical contact. Thus, the labyrinth seal provides a seal in the housing of the separating device between the first region and the second region, maintaining a permanent seal without wear.

[0020] The first sealing section, which is formed on the separating element, and the second sealing section, which is formed on the housing, for example on the cover assembly, provide a non-contact seal between the separating element and the at least one inner wall of the housing, for example the cover assembly, in which a sealing effect of the labyrinth seal on an extension of a flow path is achieved by means of the first and second sealing sections in a gap to be sealed between the separating element and the at least one inner wall of the housing, for example the cover assembly.The first and second sealing sections, when combined in the assembled housing, provide a flow resistance that is significantly higher than the gap to be sealed. In other words, the first and second sealing sections in the assembled housing act together as a labyrinth seal such that an interlocking or meshing of the first and second sealing sections in the housing between the rotating separating element and the cover assembly stationary thereto achieves a sealing effect. For example, the interlocking of the first and second sealing sections can lead to turbulence in a labyrinth structure created by the interlocking sealing sections, so that the labyrinth seal already achieves a sufficient sealing effect without the need for additional sealants and / or sliding seals. A friction-free and wear-free seal is provided in the separating device in a simple manner.In this case, the labyrinth seal can be formed by an interlocking of curved web structures, wherein the curved web structures in the first and second sealing sections are designed such that, despite the curvature, they are arranged in a contactless interlocking when the housing assembly and the cover assembly are mounted in the housing. In the case of curved webs, it can be advantageous if the curved webs are designed to be elastic, so that when the separating element is inserted into the housing or when the cover assembly is mounted on the housing assembly, the first and second sealing sections can slide past one another despite mutual undercuts in order to arrive at the contactless, interlocking arrangement. In contrast, linearly designed webs, i.e. webs without a curvature, provide simplified assembly, since with linear webs there are no undercuts of webs in the various sealing sections.

[0021] In various illustrative embodiments of the first and / or second aspect of the invention, the separating element can be provided as a separating element that is at least partially drum-like or hollow-cylindrical or shell-like or disc-shaped, such as a separating drum or a separating shell or a separating disc.

[0022] In illustrative examples in which the singulation device comprises a singulation element of the singulation drum type, the labyrinth seal is formed such that a first sealing section of the labyrinth seal is formed on an outer circumferential surface surrounding the singulation drum, and a second sealing section of the labyrinth seal, engaging therewith, is formed on the inner walls of the housing. For example, the through-openings in the singulation drum are formed as at least one radial row of through-openings, and the labyrinth seal comprises sealing sections formed on the outer circumferential surface of the singulation drum, each of which is formed between an end edge of the singulation drum and the at least one radial row on the outer circumferential surface of the singulation drum.This allows a contactless seal to be created on the casing surface between a surface area of ​​the singling drum with through openings formed therein and the spatial areas at the front edges. This is advantageous regardless of whether seed is fed in on the outer casing surface, so that the first area or overpressure area is provided on the outer casing surface during operation, with the second area or underpressure area being provided in the interior area of ​​the singling drum, which is partially delimited by the inner surface of the casing of the singling drum, or whether seed is fed in on the inner casing surface, so that the first area or overpressure area is provided on the inner casing surface.Overpressure area is provided during operation, wherein the second area or negative pressure area is provided during operation in the outer area of ​​the separating drum, which is partially limited by the outer surface of the casing of the separating drum.

[0023] In specific illustrative examples of the first and / or second aspect of the invention, the through-openings can, for example, extend substantially axially or radially through the singulating element without limitation, depending on the type of singulating element, either as a singulating disc or singulating tray, or as a singulating drum. For example, the through-openings can be formed as through-holes penetrating the singulating element substantially parallel or radially to the axis of rotation of the singulating element, such as in the case of a singulating disc or singulating tray. Alternatively, the through-openings can be provided as through-holes formed radially with respect to the axis of rotation if the singulating element is provided as a hollow cylindrical element, such as a singulating drum.

[0024] In some advantageous embodiments, the housing, for example the housing assembly, can further comprise a cover element held by a holder, wherein the holder is mounted on the housing, for example on the cover assembly, in a rotationally fixed manner, and the cover element is designed to prevent the pressure difference at a suitable location when the singling element rotates. The cover element is arranged in the housing relative to the singling element on a side opposite the seed side of the singling element in order to cover a passage opening of the singling element covered by a grain of seed on the seed side from the opposite side as well, thereby preventing the pressure difference from being present at the passage opening. This enables the granular material to be dispensed at a precise time and location after a predetermined transport (path) through the singling element.

[0025] In some illustrative first embodiments, the housing can be formed from a housing assembly and a cover assembly, and the cover assembly can further comprise a housing cover and a bell insert that is inserted into the housing cover in a rotationally fixed manner, wherein the second sealing section is formed on a circumference of the bell insert. In this case, the second region is defined by the bell insert independently of the housing cover. Thus, a pressure difference can be provided at the separating element. Leakage of the seal can be determined via the geometry of the second sealing section, and the pressure difference between the first and second regions in the housing can be influenced accordingly. Furthermore, additional sealing of the housing can be achieved by means of the housing cover.

[0026] In an advantageous refinement of the illustrative first embodiments, the cover assembly can further comprise a cover element that is rotationally fixed to the cover assembly and is designed to prevent the pressure difference at a suitable location when the separating element rotates. The cover element can rotationally fixedly mount the bell insert accommodated in the housing cover to the housing cover. This allows for reliable installation of the bell insert in the housing cover in a simple manner. For example, the cover element can be attached to a ring insert that can be removably and rotationally fixedly mounted in the housing cover. Mounting the ring insert can simultaneously rotationally fix the bell insert to the housing cover.The bell insert can also be installed in the housing cover in such a way that the bell insert can be moved axially within the housing cover, so that manufacturing tolerances can be compensated for by this axial displacement. For this purpose, the insertion or insertion depth of the bell insert in the housing cover (as a measure of the spacing between the bell insert and the housing cover) can be manually adjustable or self-adjusting due to the flow and pressure, in particular by means of, for example, a spring-loaded holder for the bell insert in the housing cover. For example, a spring element can be provided between the bell insert and the housing cover and between the bell insert and the cover element, e.g. a ring insert, which allows axial displacement of the bell insert against the spring action of the spring element.

[0027] In a further advantageous embodiment of the illustrative first embodiments, the housing cover can have a first flow channel or, with an additional component that can be fastened to the housing cover, form the first flow channel, which is designed to provide an overpressure at the second sealing section on the circumference of the bell insert between the bell insert and the housing cover. The housing cover can have a second flow channel, which is designed to provide a fluid connection between an environment of the separating device and the second region or to apply a negative pressure to the second region. By providing flow channels in the housing cover, impairment of the first and second regions can be avoided, since these are defined separately by the separating element in the housing assembly and the bell insert in the cover assembly.Furthermore, the first and second flow channels can be used to guide flows in the cover assembly in a targeted manner.

[0028] In alternative embodiments to the illustrative first embodiments, the housing cover can form the first flow channel with the housing assembly in the housing. This allows for a compact design of the housing cover, since the first flow channel is not formed solely by the housing cover.

[0029] In an illustrative example herein, the first flow channel in the housing cover can have an end opening in a region that is substantially axially opposite a grain receiving region of the singling element. The grain receiving region refers to a region of the singling element at which seed is received by the singling element and can be understood as a region of the surface of the singling element on a seed side of the singling element that is directed towards a seed supply, for example, on a circumferential segment of the disc within an angular range of + / - 45°, in particular + / - 30°. 0The grain receiving area can be arranged in the region of the lower half of the singling element, in particular with regard to the direction of rotation of the singling element in front of a seed outlet from the housing. In this case, an exact or approximate arrangement relative to the grain receiving area can be within a tolerance of no more than 30% of a radius of the singling element, or of no more than 20% of a radius of the singling element, or of no more than 15% of a radius of the singling element, or of no more than 10% of a radius of the singling element, or of no more than 5% of a radius of the singling element. In this way, flow can be supplied to the labyrinth seal at the grain receiving area, so that a sealing effect of the labyrinth seal can be optimized locally at the grain receiving area in a simple and reliable manner, so that a fluid flow is directed to an area in which grain picking is currently taking place and / or has taken place.This directed fluid flow compensates for any leakage of the labyrinth seal in the grain intake area.

[0030] In some illustrative second embodiments, the housing can be formed from a housing assembly and a cover assembly, and the cover assembly can comprise a housing cover with the second sealing section formed on an inner surface of the housing cover, which second sealing section delimits a radial inner region from a radial outer region in the housing cover, wherein in the assembled housing, the radial inner region defines the second region. This represents a structurally greatly simplified cover assembly in which the labyrinth seal is formed directly in the housing cover. This eliminates the need for an additional insert in the housing cover, and the cover assembly can be manufactured cost-effectively and assembled very quickly with very few manual steps.

[0031] In an advantageous configuration of the illustrative second embodiments, the housing cover can have a first flow channel designed to provide an overpressure in the radial outer region between the housing cover and the separating element. The housing cover can have a second flow channel designed to provide a fluid connection between an environment of the separating device and the second region or to apply a negative pressure to the second region. The flow channels can be used to guide desired fluid flows in the cover assembly in a targeted manner, so that at least the second region can be subjected to a suitable pressure. Furthermore, a sealing effect of the labyrinth seal can also be improved by providing a flow directed towards the labyrinth seal.

[0032] In a further advantageous embodiment of the illustrative second embodiments, the first flow channel in the housing can further be designed to apply an overpressure to a grain receiving area of ​​the singulating element relative to the second area. In this case, an overpressure flow is supplied to the grain receiving area by means of the first flow channel, and grain reception is improved because the overpressure flow flows through a grain bed in the grain receiving area, thus reducing friction and holding forces of grains in the grain receiving area. Accordingly, individual grains can be more easily removed from a pile of material. Furthermore, the overpressure flow guided through the first flow channel at the grain receiving area can prevent grains from becoming stuck in front of the gap, which, especially in the case of light grains, prevents grains from becoming stuck in front of the gap between the housing and the singulating element.

[0033] In a further advantageous refinement of the illustrative second embodiments, the separating element can have two radial rows of through-openings, wherein a radial row of through-openings located radially inward with respect to the first sealing section has openings facing the radial inner region and corresponds to the through-openings for entraining individual grains of the granular material, and wherein a radial row of through-openings located radially outward with respect to the first sealing section, when the housing is mounted, has openings facing the radial outer region and being in fluid communication with the first flow channel in the housing cover. The output capacity of the separating device can be increased and / or flow channels can be provided in a simple manner through the separating element.

[0034] In some illustrative embodiments, the first and second sealing sections can be formed by a plurality of webs that are arranged in the housing in an interlocking manner. For example, at least two webs can be formed in the first sealing section, while at least one web is formed in the second sealing section, wherein the webs in the first and second sealing sections can be in non-contact meshing engagement. Alternatively, at least one web can be formed in the first sealing section, while at least two webs are formed in the second sealing section, wherein the webs in the first and second sealing sections can be in non-contact meshing engagement. The webs can have the same or different lengths. For example, the lengths of the webs can decrease from radially inner to radially outer webs (monotonic or strictly monotonic).In some specific examples herein, a radially innermost web can have the greatest length and outwardly following webs can have the same or different (e.g. decreasing) lengths. This can structurally improve the sealing effect of the labyrinth seal. Different web lengths can create different sealing areas radially all the way around, so that in areas with poor sealing and thus increased flow, any dust or contamination that may have accumulated in the labyrinth seal can be blown out. In some illustrative embodiments, the labyrinth seal between the at least one inner wall of the housing, for example the cover assembly, and the separating element can be designed as an annular labyrinth seal formed in the circumferential direction of the separating element.Additionally or alternatively, the separating element can be inclined relative to a vertical orientation in the housing. The inclination of the separating element can be within an angle range between 0 and 45°, for example, between 0° and 30°, relative to a vertical line in the housing. An inclined separating element provides improved adhesion of granular material in the through-openings in the grain receiving area. An annular labyrinth seal provides a beneficial sealing effect at the edge of the separating element.

[0035] In some illustrative embodiments, the pressure reservoir can provide a pressure that is elevated relative to a pressure in the second region, and the housing, for example, the housing assembly, can have a supply line connected to the first region (and, for example, the cover assembly, if present) to apply the elevated pressure to the first region and a radially outer side of the labyrinth seal, respectively. This advantageously provides an overpressure-type separating device.

[0036] In some illustrative embodiments, the pressure reservoir can provide a pressure that is lower than the pressure in the first region, and the housing (e.g., the cover assembly, if present) can have a supply line configured to apply a pressure that is higher than the lower pressure to a radially outer side of the labyrinth seal. This advantageously provides a separating device in which the increased pressure can be higher than the pressure in the first region, so that a sealing effect of the labyrinth seal can be optimized.

[0037] In the pressure difference-based singulation described herein, the singulation element always divides the housing into a region of higher pressure and a region of lower pressure. In order for grains to accumulate on the singulation element, the granular material is located in the region of higher pressure. This region is referred to as the overpressure region, and the region of lower pressure as the underpressure region. The pressure level in the overpressure region can be higher than the pressure level of an ambient atmosphere. The pressure level in the underpressure region can be lower than the pressure level of an ambient atmosphere or at ambient atmosphere. This is not restrictive, as it is essential that the pressure level in the overpressure region is higher than the pressure level in the underpressure region.

[0038] Further details of the invention can be found in the following detailed description of illustrative embodiments with reference to the drawings. The drawings show:

[0039] Fig. 1 shows a sowing unit of an agricultural sowing machine in a perspective exploded view according to some illustrative embodiments;

[0040] Fig. 2 shows an agricultural singling device in a perspective view of an opened housing according to illustrative embodiments;

[0041] Fig. 3 shows the agricultural singling device from Fig. 2 in a cross-sectional view;

[0042] Fig. 4 shows the agricultural singling device from Fig. 2 in a further cross-sectional view;

[0043] Fig. 5 is a sectional view of a cover assembly according to some illustrative embodiments;

[0044] Fig. 6 shows the agricultural singulating device from Fig. 2 in a further cross-sectional view to illustrate some flow paths;

[0045] Fig. 7 shows a sowing unit of an agricultural seed drill in a perspective exploded view according to alternative embodiments; and

[0046] Fig. 8 shows the agricultural singling device from Fig. 7 in a schematic cross-sectional view of a section of the singling device.

[0047] With reference to Fig. 1, a sowing unit 2 of an agricultural seed drill (not shown) is shown in a perspective exploded view. The sowing unit 2 can be fastened by means of support elements 1 to a frame oriented transversely to the direction of travel F of the seed drill (not shown) (in Fig. 1, a frame element 1a of a frame oriented perpendicular to the direction of travel F, for example a telescopic frame, is shown, wherein the frame element 1a represents a telescopic frame element) of the agricultural seed drill (not shown). The sowing unit 2 can be fastened in the seed drill (not shown) as one of several sowing units (not shown) to the frame (not shown), so that by means of at least one further sowing unit (not shown) in addition to the sowing unit 2, one or more further seed furrows can be filled with seed and / or fertilizer can be applied along one or more furrows.The sowing unit 2 can be movable relative to the frame.

[0048] As shown in Fig. 1, the sowing unit 2 has a storage hopper 3 for storing granular material to be spread, in particular seed and / or fertilizer. The lower region of the storage hopper 3 is designed as an outlet area in which an outlet opening (not shown in Fig. 1, see reference numeral 4 in Fig. 2) is arranged. The granular material to be spread is fed via the outlet opening (not shown in Fig. 1, see reference numeral 4 in Fig. 2) to a singulating device 5, which is arranged below the storage hopper 3.

[0049] The singling device 5 will now be described in more detail with reference to Fig. 1 to 3. The singling device 5 comprises a housing formed from a housing assembly 6a and a cover assembly 6b detachably mounted on the housing assembly 6a. Arranged within the housing is a singling element 7 which can be driven rotationally in a direction of rotation R about a rotation axis D and is preferably at least partially rotationally symmetrical. The singling element 7 is designed to at least partially singulate the granular material that can be provided in the housing by means of a feed from the storage container 3. The housing has a shaft W which is rotatably mounted on the housing assembly 6a and by means of which the singling element 7 is rotatably driven during operation of the singling device 5. Although the singling element 7 is shown in Fig.1 to 3 as being vertically oriented in the housing, the orientation of the separating element 7 in the housing may also deviate from a vertical orientation without limiting the scope of the description in this regard. Reference is made here to the explanation of inclined separating elements in the description, whereby the disclosure regarding inclined separating elements is incorporated in its entirety by reference at this point.

[0050] In illustrative embodiments herein, the separating element 7 represents a separating element 7, which is at least partially designed as a circular disk or shell in the form of a separating disk or separating shell and is rotationally fixedly coupled to the shaft W, such that the shaft W sets a specific rotational movement of the separating element 7 at a predetermined rotational speed. The separating element 7 is arranged in the housing such that a first region B1 is defined between the separating element 7 and the housing assembly 6a, and a second region B2 is defined between the separating element 7 and the housing assembly 6b. A pressure difference can be generated in the interior space between the first region B1 and the second region B2 by means of a pressure reservoir (not shown).

[0051] The housing assembly 6a has an opening into which the separating element 7 is at least partially received, wherein the opening of the housing assembly 6a can be surrounded by an annular flange portion (cf. reference numeral 6af in Fig. 2).

[0052] However, this does not represent a limitation and, as an alternative to the illustrated embodiment, the separating element 7 can also be designed as a separating drum (not illustrated) that is at least partially drum-like or cylinder-like, instead of the explicitly illustrated separating element 7.

[0053] With further reference to Figs. 1 to 3, the separating element 7 has suitable through-openings 11 for entraining individual grains of the granular material at regular intervals along its circumferential direction and / or in its outer region near the circumferential line, wherein the through-openings 11 create spatial connections between the first region B1 and the second region B2 of the housing, and the grains accumulate at these through-openings 11 due to the pressure difference. Furthermore, the separating device 5 can further comprise a cover element 12 at a suitable location in the housing, which temporarily covers the through-openings 11 to prevent the pressure difference and thus a continuous accumulation of the transported grains.

[0054] With reference to the illustration in Fig. 2, the through openings 11 are arranged in the circumferential direction of the separating element 7 along a diameter or a radius starting from the axis of rotation D in the region of an outer disk circumference. Alternatively, it is also conceivable for the through openings 11 to be arranged on the circumference of the separating element 7. Although in Figs. 1, 2 and 4 only one radial row of through openings 11 (ie the through openings 11 are only formed in a ring arrangement with a substantially fixed radius) is formed in the separating element 7, this does not represent a restriction and instead of one radial row, two or more concentric radial rows of through openings can be provided.For example, the through-openings of the various radial rows may all have the same size, or each radial row may have through-openings with an associated fixed size, wherein the through-openings of at least two radial rows differ from one another.

[0055] According to illustrative and non-limiting embodiments, the illustrated singling device 5 can further be designed as an overpressure singling device, wherein a pressure which is greater than a pressure in the second region B2 can be generated in the first region B1 via a pressure reservoir (not shown) that can be connected to a pressure supply line 8, such as a blower (not shown). Alternatively, a negative pressure singling device or another type of singling device is also conceivable, for example in which the first region B1 is connected to the ambient atmosphere via the pressure supply line 8, while the second region B2 is connected to a negative pressure reservoir (not shown), e.g. a suction element (not shown), via a suitable supply line (not shown), so that a pressure in the second region B2 is lower than a pressure in the first region B1.

[0056] In general, in the illustrated embodiments, the housing is divided into at least the first region B1 and the second region B2 by means of the separating element 7. This division of the housing via the separating element 7 is designed such that a pressure difference can be generated between at least the first region B1 and the second region B2.

[0057] As described above, the first region B1 and the second region B2 of the housing are spatially connected to one another via the through-openings 11, such that individual grains of the granular material can be carried along between the two regions B1, B2 within the through-openings 11 due to the pressure difference, in particular a suction effect resulting therefrom. Individual grains are transported in the direction of rotation R to the cover element 12 on a first side of the separating element 7 facing the first region (generally the side facing the region with higher pressure). The cover element 12 is arranged on a side of the separating element 7 opposite the first side. The cover element 12 is further configured to temporarily prevent the pressure difference, in particular locally in the region of the cover element 12, by at least partially covering at least one through-opening 11.Due to the suppressed pressure difference, the at least one grain carried by the singling element 7 is released for detachment in the region of the covering element 12. Thus, a grain released by the covering element 12 is transferred to a seed placement device 130 at a defined position, as shown in Fig. 1. In illustrative examples, the covering element 12 is designed in the form of a roller that rolls along the disc due to friction while the singling element 7 rotates. As shown in Fig. 1, the seed placement device 130 comprises furrow opening elements 14 designed as disc coulters, depth control elements 15, and devices 16 for closing a furrow. In addition, the seed placement device 130 can comprise a delay device (not shown). The delay device reduces the movement speed of a grain.The deceleration device can comprise a catching element that fixes the grain at the bottom of a furrow. Alternatively or additionally, the deceleration device can comprise a braking element that changes the speed of the grain based on the advance speed of the sowing unit 2. The catching element can be designed, for example, to be rolling or grinding. The braking element can be designed, for example, as an air outlet or to be rotating.

[0058] With reference to Fig. 1, at least one ejection member 17 is also arranged within the housing, which can be driven by the separating element 7, for example in that the ejection member 17 is driven by the engagement of the teeth in through-openings. The ejection member 17 is arranged on the second side of the separating element 7 and behind the cover element 12 in the direction of rotation R. The ejection member 17 is designed to engage at least partially in the through-openings 11 and thus to clean the through-openings 11 of blockages and / or dirt. In this case, stuck dirt, grains or other deposits within the through-openings 11 are released by pressing out ejection elements which are formed on the ejection member 17 and are designed to engage in the through-openings 11.However, this does not constitute a limitation and instead no pressure interruption element and only the ejection organ may be provided.

[0059] With reference to Fig. 1, 2, 3, 4 and 6, the cover assembly 6b has a housing cover 6b1 and a bell insert 6b2 which is inserted into the housing cover 6b1 in a rotationally fixed manner. The bell insert 6b2 represents a half-shell element which only has a central opening 13c. Furthermore, the bell insert 6b2 is not in direct mechanical contact with the separating element 7, so that rotation of the separating element 7 is not impaired by mechanical contact between the separating element 7 and the bell insert 6b2. In particular, the separating element 7 rotates freely within the housing. By means of the central opening 13c, the bell insert 6b2 can be attached to and plugged onto a central cylindrical projection 13d on an inner surface of the housing cover 6b1.This allows for a rotationally fixed and precise fixation of the bell insert 6b2 in a predetermined position without the risk of misaligned assembly of the bell insert 6b2 on the housing cover 6b1. The central opening 13c and the projection 13d further provide a connection between the region B2 and a flow channel 28 in the housing cover 6b1, which is connected to the surroundings of the separating device 5. This allows the region B2 to be maintained at ambient pressure. Alternatively, it can be coupled to a vacuum reservoir (not shown) via the flow channel 28.

[0060] In some illustrative embodiments, the bell insert 6b2 can be installed in the housing cover 6b1 in such a way that the bell insert 6b2 is inserted in the housing cover 6b1 so as to be axially displaceable and is mounted at a desired insertion or insertion depth in the housing cover 6b1. By installing at the desired insertion and insertion depth in the housing cover 6b1, manufacturing tolerances can be compensated for by installing with a set axial displacement. For example, the insertion or insertion depth of the bell insert 6b2 in the housing cover 6b1 can be set manually by inserting or screwing the bell insert 6b2 onto the projection 13d, wherein the projection 13d is an external thread with a predetermined thread pitch (not shown) or is designed to displace the bell insert 6b2 in the axial direction along the projection 13d. In other illustrative examples, the insertion or insertion depth can furthermoreThe insertion depth of the bell insert 6b2 in the housing cover 6b1 is adjusted due to flow and pressures in the housing acting on the bell insert 6b2. In other illustrative examples, a spring-loaded holder for the bell insert 6b2 in the housing cover 6b1 can also be provided, wherein the insertion depth of the bell insert 6b2 in the housing cover 6b1 is adjusted by spring elements (not shown). This spring-loaded holder can be self-adjusting in that an axial displacement of the bell insert 6b2 in the housing cover 6b1 is adjusted due to flow and pressures in the housing acting on the bell insert 6b2.For example, a resilient element (not shown) can be provided between the bell insert 6b2 and the housing cover 6b2 and between the bell insert 6b2 and the ring insert 12a, which allows an axial displacement of the bell insert 6b2 counter to a spring action of the resilient element (not shown).

[0061] With reference to Fig. 2, the bell insert 6b2 can be fixed to the housing cover 6b1 by the cover element 12 and / or the ejection member 17, which is mounted on the projection 13d. The cover element 12 and / or the ejection member 17 can be attached to a ring element 12a, which is mounted on the projection 13d and thus prevents the bell insert 6b2 from slipping off the projection 13d. For example, the ring element 12a can be detachably or permanently mounted on the projection 13d by means of screws or bolts.

[0062] With reference to Fig. 2, a fastening of the housing assembly 6b to the housing assembly 6a is described. The housing assembly 6a has projections 14a, 14b, each with through-openings 16a and 16c formed therein. The cover assembly 6b has pin locking elements 16b and 16d, which are designed to be inserted into the through-openings 16a and 16c for a locking connection. For example, the pin locking elements 16b and 16d are formed on the housing cover 6b1 in order to detachably mount the housing cover 6b1 with the bell insert 6b2 inserted therein to the housing assembly 6a. Alternatively, the pin locking elements 16b and 16d can be formed on the bell insert 6b2. In further alternative embodiments, through holes (not shown) may be formed on the housing cover 6b1 or the bell insert 6b2 to engage with pin locking elements (not shown) on the housing assembly 6a.When the housing cover 6b1 is mounted on the housing assembly 6a, the housing is sealed, whereby, for example, the housing cover 6b1 with a sealing surface when mounted on the housing assembly 6a seals against a seal of the housing assembly 6a.

[0063] With reference to Figs. 3, 4, and 6, the separating device 5 further comprises a labyrinth seal 20 formed by a first sealing portion 22 on a periphery of the separating element 7 and a second sealing portion 24 on the cover assembly 6b, for example, on a periphery of the bell insert 6b2, such that the first sealing portion 22 and the second sealing portion 24 are interlocking structures without mechanical contact. Thus, the labyrinth seal 20 provides a seal in the housing of the separating device 5 between the first region B1 and the second region B2, maintaining a permanent seal without wear.

[0064] The first sealing section 22 formed on the separating element 7 and the second sealing section 24 formed on the cover assembly 6b provide a non-contact seal between the separating element 7 and the cover assembly 6b, in which a sealing effect of the labyrinth seal 20 is achieved by an extension of a flow path by means of the first and second sealing sections 22, 24 in a gap to be sealed between azimuthal edges of both the separating element 7 and the cover assembly 6b.The first and second sealing sections 22, 24, when combined in the assembled housing, provide a flow resistance that is significantly higher than the gap to be sealed. In other words, the first and second sealing sections 22, 24 in the assembled housing act together as a labyrinth seal 20 such that an intermeshing or interlocking of the first and second sealing sections 22, 24 in the housing between the rotating separating element 7 and the cover assembly 6b stationary therewith achieves a sealing effect. For example, the intermeshing of the first and second sealing sections 22, 24 can lead to turbulence in a labyrinth structure 20 formed by the intermeshing sealing sections 22, 24, so that the labyrinth seal 20 already achieves a sufficient sealing effect without the need for additional sealants and / or sliding seals.A frictionless and wear-free seal is provided in the separating device 5 in a simple manner.

[0065] In illustrative embodiments, the labyrinth seal 20 can be formed by a plurality of webs 22s, 24s, wherein the plurality of webs 22s, 24s of the first and second sealing sections 22, 24 are in meshing, but non-contact, engagement with one another. For example, the first sealing section 22 can have one web that is in meshing engagement with two webs of the second sealing section 24, or vice versa. With regard to the labyrinth seal 20 shown in Figs. 3, 4, and 6, the first sealing section 22 can have two webs 22s, and the second sealing section 24 can have two webs 24s. The webs 22s and the webs 24s can be in meshing, but non-contact, engagement with one another, as shown in Figs. 3, 4, and 6.In this case, a radially inner web of the first sealing section 22 can be longer than a radially outer web of the sealing section 22 in order to extend a flow path in the region B2 towards the labyrinth seal 20 and to further suppress leakage currents.

[0066] With reference to Fig. 3, 5 and 6, further advantageous embodiments are described which, in addition to the labyrinth seal 20, provide for the application of an overpressure to the labyrinth seal 20 by the cover assembly 6b. This can improve the sealing effect of the labyrinth seal 20 by suppressing leakage flows through the labyrinth seal 20. For this purpose, as shown in Fig. 3, the cover assembly 6b has a flow channel 26 which is designed to apply an overpressure applied via the flow channel 26 to the labyrinth seal 20 on the cover side. For example, the housing cover 6b1, as shown in Fig. 3, 5 and 6, has the flow channel 26 which is designed to provide an overpressure at the second sealing section 24 on the circumference of the bell insert 6b2 between the bell insert 6b2 and the housing cover 6b1.The housing cover 6b1 may further comprise the flow channel, which is designed to provide a fluid connection between an environment of the separating device and the second region B2 or to apply a negative pressure to the second region B2, as described above.

[0067] In some illustrative embodiments, the labyrinth seal 20 between the cover assembly 6b and the separating element 7 can be designed as an annular labyrinth seal 20 formed in the circumferential direction of the separating element 7.

[0068] 3 and 6, the first flow channel 24 in the housing cover 6b2 has an end opening 25a that is in fluid communication with the flow channel 26 and opens into a channel region of the flow channel 26 that is defined between the bell insert 6b2 and the housing cover 6b1. This channel region of the flow channel 26 directs the fluid flow at one end to an area that is essentially axially opposite a grain receiving area 30 of the singulating element 7. In this case, an overpressure flow is guided to the grain receiving area 30' by means of the flow channel 24, and grain receiving is accordingly improved, since the overpressure flow flows through a grain bed in the grain receiving area 30. This reduces the friction and holding forces of grains in the grain receiving area 30, so that individual grains can be more easily separated from a heap.Furthermore, the overpressure flow at the grain receiving area 30 can prevent grains from becoming stuck in front of the gap, which, especially in the case of light grains, prevents grains from becoming stuck in front of the gap between the housing and the separating element 7. Fig. 6 illustrates a flow path of a fluid flow in the flow channel 26 by means of arrows that enter through the end opening 25a into the channel area of ​​the flow channel 26 between the bell insert 6b2 and the housing cover 6b1 and are directed towards the area that is essentially axially opposite the grain receiving area 30 of the separating element 7. Furthermore, the fluid flow in the channel area is distributed towards the labyrinth seal 20, as indicated by the arrows pointing vertically upwards in the illustration in Fig. 6.This allows an annular configuration of the labyrinth seal 20 to be distributed in the area between the housing cover 6b1 and the bell insert 6b2, directed toward the labyrinth seal 20, whereby the cylindrical projection 13d, to which the bell insert 6b2 is mounted in a rotationally fixed manner, prevents a connection to the opening 13c. Thus, there is no connection between the flow channel 26 and the area B2 from the cover assembly 6b.

[0069] With reference to Fig. 5, an illustrative and non-limiting embodiment of the flow channel 26 in the housing cover 6b1 is shown, which shows a guidance of overpressure flow to the opening 25. For example, the flow channel 26 can be designed to connect the opening 25 to a supply line 9 in the cover assembly 6b, which is connected to the supply line 8 in the housing assembly 6a. The supply line 8 can, as shown in Fig. 4, have a branch in the housing assembly 6a, so that an overpressure flow S provided by the supply line 8 is split to apply an overpressure to the region B1 by means of an overpressure partial flow S1 and to apply a branched overpressure partial flow S2 via the supply line 9 and the flow channel 26 to the labyrinth seal 20. The overpressure partial flow S1 can be greater than the overpressure partial flow S2.This does not represent a restriction and the overpressure partial flow S2 can also be provided for separation via an additional line (not shown).

[0070] With further reference to Figs. 3 and 5, the flow channel 28 is also shown, which connects the opening 13c in the lid assembly 6b with the surroundings of the separating device 5 or a vacuum reservoir (not shown).

[0071] With reference to Figs. 7 and 8, a sowing unit 2' of an agricultural seed drill (not shown) according to alternative embodiments is shown in a perspective exploded view. The sowing unit 2' differs from the sowing unit 2 described above with reference to Fig. 1 by a singling device 5' which is provided instead of the singling device 5 in Fig. 1. Like reference numerals between Figs. 1 and 7 designate like elements which correspond to one another in Figs. 1 and 7, reference being made to the description of these like elements with regard to Fig. 1 above and being fully incorporated by reference into the description of Figs. 7 and 8.

[0072] With further reference to Fig. 7 and 8, the sowing unit 2' can be fastened by means of support elements 1 to a frame oriented transversely to the direction of travel F of the sowing machine (not shown) (in Fig. 7, a frame element 1a of a frame oriented perpendicular to the direction of travel F, for example a telescopic frame, is shown, wherein the frame element 1a represents a telescopic frame element) of the agricultural sowing machine (not shown). The sowing unit 2' can be fastened to the frame (not shown) in the sowing machine (not shown) as one of several sowing units (not shown), so that by means of at least one further sowing unit (not shown) in addition to the sowing unit 2', one or more further seed furrows can be filled with seed and / or fertilizer can be applied along one or more furrows. In some illustrative examples, the sowing unit 2' can be movable relative to the frame to compensate for soil contours.For example, the at least one sowing unit 2' can be provided on a parallelogram linkage (not shown) or another linkage arrangement (not shown) in a height-variable and / or laterally displaceable manner on a sowing machine (not shown).

[0073] As shown in Fig. 7, the sowing unit 2' has a storage container 3 for storing granular material to be spread, in particular seed and / or fertilizer. The lower region of the storage container 3 is designed as an outlet region in which an outlet opening (not shown in Fig. 1, see the corresponding description of reference numeral 4 in Fig. 2, which is included in full at this point) is arranged. Via the outlet opening (not shown in Fig. 1, see reference numeral 4 in Fig. 2), the granular material to be spread is fed to a singulating device 5', which is arranged below the storage container 3.

[0074] The agricultural singling device 5' is provided for singling granular material, in particular seed and / or fertilizer. In illustrative embodiments, as will now be described with reference to Figs. 7 and 8, the singling device 5' comprises a housing including a housing assembly 6a with a rotatably mounted shaft W defining a rotation axis D, and a cover assembly 6b' detachably mounted on the housing assembly 6a. Furthermore, the singling device 5' comprises a singling element 7, which is received in an interior space defined in the housing. The singling element 7 is coupled to the shaft W, such that the singling element 7 is rotatably mounted relative to the housing. The singling element 7 is arranged in the housing such that a first region BT (cf.corresponding description of reference symbol B1, which is included in full at this point) and a second region B2' (cf. corresponding description of reference symbol B2, which is included in full at this point) is defined between the separating element 7 and the cover assembly 6b', wherein a pressure difference can be generated between these regions for the accumulation of granular material on the separating element 7. The separating device 5' further comprises a labyrinth seal 20', which is formed by a first sealing section 22 on a circumference of the separating element 7 and a second sealing section 24' on the cover assembly 6b' such that the first sealing section 22 and the second sealing section 24' are interlocking structures without mechanical contact. With further reference to Fig.8, the cover assembly 6b' comprises a housing cover 6bT with a first flow channel 26', which is designed to provide an overpressure at the radial outer region 6ra' between the housing cover 6b1' and the separating element 7. The housing cover 6bT further has a second flow channel 28', which is designed to provide a fluid connection between an environment of the separating device 5' and the second region B2' or to apply a negative pressure to the second region B2'. The flow channel 28' can be designed corresponding to the flow channel 28, the description of which is hereby incorporated by reference in its entirety. In some illustrative examples, for example, an opening ©bi is formed in the housing cover 6b1', through which a connection to the environment or a negative pressure reservoir can be established.The opening ©bi may, in some examples, be formed coaxially with the rotational axis D. Furthermore, the cover assembly 6b' may further comprise a cover element 12 and a stripping element 17, wherein the cover element, as already described with regard to Fig. 1 above, functions to prevent the pressure difference and thus a continuous deposition of transported grains, reference being made to the corresponding description of the elements 12 and 17 above.

[0075] In illustrative embodiments herein, the first flow channel 26' in the housing cover 6b2' can be further configured to apply an overpressure to a grain receiving area 30' of the singulating element 7 relative to the second area B2'. The grain receiving area 30' refers to an area of ​​the disk where grains are received by the singulating element 7.

[0076] With reference to Fig. 8, the separating element 7 has two radial rows R1, R2 of through-openings, wherein a radial row R1 (a first row) of through-openings located radially inward with respect to the first sealing section 22 has openings facing the radial inner region 6ri' and corresponding to through-openings 11 for entraining individual grains of the granular material. A radial row R2 (a second row) of through-openings located radially outward with respect to the first sealing section has, when the housing is mounted, openings 1T that face the radial outer region 6ra' and are in fluid communication with the first flow channel 26' in the housing cover 6b1'. The size and / or number of openings 11 and 11 1may be the same or different, whereby a size and / or number of the openings 1T of the 2nd row may be larger than a size and / or number of the openings 11 of the first row. In some specific illustrative examples, the size of the openings 11 may be larger than the size of the openings 1T. For example, the size of the openings 1T of the second row may be + / - 50% of the size of the opening of the 1st row. Additionally or alternatively, the number of openings of the respective rows may be different.

[0077] With further reference to Fig. 8, the labyrinth seal 20' is shown according to some illustrative embodiments. The first and second sealing sections 22, 24' can be formed, similar to the sealing sections 22, 24, by a plurality of webs 22s and 24s', which are arranged in an interlocking manner in the housing. For example, the webs of the plurality of webs 22s, 24s' of the first and second sealing sections 22, 24' are in meshing, but non-contact, engagement with one another. For example, the first sealing section 22 can have one web that is in meshing engagement with two webs of the second sealing section 24', or vice versa. With regard to the labyrinth seal 20' shown in Fig. 8, the first sealing section 22 can have two webs 22s and the second sealing section 24' can have one web 24s'. The webs 22s and the web 24s' can be in non-contact meshing engagement with each other, as shown in Fig.8. The webs of the first sealing section 22 can have the same or different lengths. As an alternative to the labyrinth seal 20' shown, the first sealing section 22 can have more than two webs 22s, and the second sealing section 24' can have more than one web 24s', wherein the webs of the first and second sealing sections 22, 24' mesh with one another without contact.

[0078] In some illustrative embodiments and with reference to Fig. 8, the singling element 7 can be inclined by an angle with respect to a vertical orientation in the housing, for example an angle between 0° and 45°, for example between 0° and 25°, preferably between 0° and 20°, more preferably between 0° and 15°. The inclination of the singling element 7 can be set such that an upper edge of the singling element 7 in the housing covers only a part of the singling element 7 in a vertical plan view of the singling element 7 in the housing. A singling element inclined in this way allows advantageous adhesion of grains in the through-openings 11 of the singling element 7, since the adhesion is supported by the weight of the grains in the grain receiving area 30.

[0079] In some illustrative embodiments, the labyrinth seal 20' between the cover assembly 6b' and the separating element 7 can be formed as an annular labyrinth seal 20' formed in the circumferential direction of the separating element 7. In some illustrative embodiments and with further reference to Fig. 8, a pressure reservoir (not shown) can provide a pressure increased compared to a pressure in the second region B2', and the housing assembly 6a can have a supply line 8' connected to the first region BT and the cover assembly 6b' in order to apply the increased pressure to the first region BT, respectively.

[0080] In some other illustrative embodiments and with further reference to Fig. 8, the pressure reservoir (not shown) can provide a pressure reduced compared to a pressure in the first region BT, and the cover assembly 6b' can have a supply line 9' configured to apply a pressure increased compared to the reduced pressure to a radially outer side of the labyrinth seal 20'. The increased pressure can be higher than the pressure in the first region BT. In this case, the pressure reservoir (not shown) can be provided as an additional, separate pressure reservoir (not shown) to at least partially apply pressure to the labyrinth seal 20'.

[0081] In some other illustrative embodiments, as shown in Fig. 8, the supply line 8' can be directly connected to the supply line 9', so that a fluid flow supplied to the supply line 8' is fed directly and completely into the supply line 9', in particular without losses. In this case, the region BT is not fed directly by the supply line 8', in particular, there is no direct supply to the region BT by the housing assembly 6a, but the region BT is fed indirectly by the supply lines 8' and 9', which supply a fluid flow to the labyrinth seal 20' via the flow channel 26'. In this case, the flow channel 26' is in fluid communication with the region B1 via the openings 1T of the radial row R2. A radially outer side of the labyrinth seal 20' is subjected to the increased pressure in order to provide a sealing effect of the labyrinth seal 20'.

[0082] Although Fig. 8 shows that the supply line 8' is only directly connected to the supply line 9', this does not represent a limitation and instead the supply line 8' in the housing assembly 6a can be designed to directly supply the area BT, wherein a branch (not shown) from the supply line 8' in the housing assembly 6a is also connected to the supply line 9' in the cover assembly 6b'. In this case, the radial row R2 with the openings 1T is not provided and the supply line 9' is only connected to the flow channel 26' in order to direct a fluid flow that branches off from the supply line 8' and is supplied to the flow channel 26' through the supply line 9' from the cover assembly 6b' only onto the labyrinth seal.

[0083] In some illustrative embodiments of the separating device 5, 5' described above, a supply of a fluid to the labyrinth seal can be provided from the side of the cover assembly 6b, 6b' in order to pressurize the labyrinth seal from the side of the cover assembly 6b, 6b'. A specific gap size can be provided in the interlocking between the first and second sealing sections 22, 24, 24' (for example, by a suitable choice of geometric dimensions for the webs of the first and second sealing sections 22, 24, 24' and / or the positioning of the webs of the first and second sealing sections 22, 24, 24'), so that a specific leakage flow through the labyrinth seal into the first region B1, BT is tolerated.For this purpose, for example, a pressure that is higher than a pressure applied to the first region B1, BT can be applied to the labyrinth seal from the cover assembly 6b, 6b', for example via a suitable pressure source and / or a nozzle formed in the cover assembly 6b, 6b', in order to direct a specific flow onto the labyrinth seal. A leakage flow flowing from the cover assembly 6b, 6b' through the labyrinth seal into the first region B1, BT can, for example, loosen granular material in the grain receiving region 30, 30', so that frictional and adhesive forces between grains in the granular material in the grain receiving region 30, 30' are reduced.

[0084] Although some illustrative embodiments describe a coupling of flow channels and / or supply lines in the lid assembly to a pressure reservoir that is provided for pressurizing the first region, this does not constitute a limitation, and instead an additional separate pressure reservoir, e.g. a blower, a pressurized gas in a container, etc., may be provided exclusively to support the application of pressure to the labyrinth seal from the lid assembly. The pressure for applying pressure to the labyrinth seal may be provided at least partially by the additional separate pressure reservoir. For example, in some specific and non-limiting embodiments herein, the additional separate pressure reservoir may be integrated into, integrable with, or coupleable with the lid assembly.

[0085] Although embodiments in which a separating element is rotatably mounted in a housing assembly are described above with reference to Figs. 1 to 8, this does not represent a limitation of the described embodiments and instead the separating element may be rotatably mounted on a housing cover.

[0086] Although in the illustration of Figures 1 to 8 the separating elements are each shown as a separating disc and / or a separating tray, this does not represent a limitation of the present description of the figures and each of the embodiments described with regard to Figures 1 to 8 can instead also be realized with a separating drum as the separating element.

[0087] Wherever approximate language such as "about", "approximately", "substantially" or similar is used in this description, this represents an approximation within a reasonable tolerance of measurement or manufacturing, for example, without limitation, a deviation of + / - 20% or less, or + / - 15% or less, or + / - 10% or less, or + / - 5%.

[0088] It is understood that the features mentioned in the previously described embodiments are not limited to these specific combinations and are also possible in any other combinations. Furthermore, it is understood that the geometries shown in the figures are merely exemplary and are also possible in any other configurations.

Claims

Claims 1. An agricultural singling device (5, 5') for singling granular material, in particular seed and / or fertilizer, comprising: a housing with a shaft (W) rotatably mounted in the interior of the housing, which defines a rotation axis (D), and a singling element (7) accommodated in the interior defined in the housing, wherein the singling element (7) is coupled to the shaft (W) such that the singling element (7) is rotatably mounted relative to the housing, wherein the singling element (7) is arranged in the housing such that a first region (B1, B1') and a second region (B2, B2') are defined in the interior, which are separated from one another by the singling element (7) in the interior, such that a pressure difference can be generated in the interior between the first region (B1, B1') and the second region (B2, B2') by means of a pressure reservoir,wherein the separating element (7) has a radial row of suitable through-openings (11) for entraining individual grains of the granular material, wherein the through-openings (11) create spatial connections between the first region (B1, BT) and the second region (B2, B2') of the housing and the grains accumulate in the first region (B1, BT) due to the pressure difference at these through-openings (11), characterized in that the separating device (5, 5') further comprises a labyrinth seal (20, 20'), which is formed in the second region (B2, B2') by a first sealing section (22) formed on a circumference of the separating element (7) and a second sealing section (24, 24') on one or more inner walls of the housing in such a way that the first sealing section (22) and the second sealing section (24, 24') form interlocking structures without mechanical contact. are., 2. Separating device (5, 5') according to claim 1, wherein the housing in the second region (B2, B2') further comprises a cover element (12) held by a holder (12a) wherein the holder (12a) is mounted on the housing in a rotationally fixed manner, and wherein the cover element (12) is designed to prevent the pressure difference at a suitable location when the separating element (7) is rotating.

3. Separating device (5) according to claim 1 or 2, wherein the housing is formed from a housing assembly (6a) which defines the first region (B1) with the separating element (7), and a cover assembly (6b) which defines the second region (B2) with the separating element (7), and the cover assembly (6b) further comprises a housing cover (6b1) and a bell insert (6b2) which is inserted into the housing cover (6b1) in a rotationally fixed manner, wherein the second sealing section (24) is formed on a circumference of the bell insert (6b2).

4. Separating device (5) according to claim 3 in conjunction with claim 2, wherein the cover element (12) mounts the bell insert (6b2) accommodated in the housing cover (6b1) on the housing cover (6b1) in a rotationally fixed manner.

5. Separating device (5) according to one of claims 3 to 4, wherein the housing cover (6b1) has a first flow channel (26) which is designed to provide an overpressure at the second sealing section (24) on the circumference of the bell insert (6b2) between the bell insert (6b2) and the housing cover (6b1), and wherein the housing cover (6b1) has a second flow channel (28) which is designed to provide a fluid connection between an environment of the separating device and the second region (B2) or to apply a negative pressure to the second region (B2).

6. Separating device (5) according to claim 5, wherein the first flow channel (24) in the housing cover (6b1) has an end opening (25) at a region which is substantially axially opposite a grain receiving region (30) of the separating element (7).

7. Separating device (5') according to claim 1 or 2, wherein the housing is formed from a housing assembly (6a) which defines the first region (BT) with the separating element (7), and a cover assembly (6b') which defines the second region (B2') with the separating element (7), and the cover assembly (6b') comprises a housing cover (6b1') with the second sealing section (24') formed on an inner surface (6bi') of the housing cover (6b1'), which seals off a radial inner region (6ri') from a radial outer region (6ra') in the housing cover (6b1') against each other delimits, whereby in the assembled housing the radial inner area (6ri') defines the second area (B2').

8. Separating device (5') according to claim 7, wherein the housing cover (6bT) has a first flow channel (26') which is designed to provide an overpressure at the radial outer region (6ra') between the housing cover (6bT) and the separating element (7), and wherein the housing cover (6b1) has a second flow channel (28') which is designed to provide a fluid connection between an environment of the separating device (5') and the second region (B2') or to apply a negative pressure to the second region (B2').

9. Separating device (5') according to claim 8, wherein the first flow channel (26') in the housing cover (6b2') is further designed to apply an overpressure to a grain receiving area (30') of the separating element (7) relative to the second area (B2').

10. Separating device (5') according to one of claims 7 to 9, wherein the separating element (7) has two radial rows of through-openings (R1, R2), wherein a radial row (R1) of through-openings lying radially inward with respect to the first sealing section has openings facing the radial inner region (6ri') and corresponds to the through-openings (11) for entraining individual grains of the granular material, and wherein a radial row (R2) of through-openings lying radially outward with respect to the first sealing section (22) has openings (1T) when the housing is mounted, which face the radial outer region (6ra') and are in fluid communication with the first flow channel (26') in the housing cover (6b1').

11. Separating device (5, 5') according to one of claims 1 to 10, wherein the first and second sealing sections (22, 24, 24') are formed by a plurality of webs (22s, 24s, 24s') which are arranged in the housing in an interlocking manner.

12. Separating device (5, 5') according to one of claims 1 to 11, wherein the labyrinth seal (20, 20') between the housing and the separating element (7) is formed as an annular seal in the circumferential direction of the separating element (7). Labyrinth seal (20, 20') is formed, and / or wherein the separating element (7) in the housing is inclined against a vertical orientation.

13. Separating device (5, 5') according to one of claims 1 to 12, wherein the pressure reservoir provides a pressure which is increased compared to a pressure in the second region (B2, B2') and the housing has a supply line (8, 8') which is connected to the first region (B1, B1') in order to apply the increased pressure to the first region (B1, BT) and a radially outer side of the labyrinth seal (20, 20').

14. Separating device (5, 5') according to one of claims 1 to 12, wherein the pressure reservoir provides a pressure which is reduced compared to a pressure in the first region (B1, BT) and the housing has a supply line (9, 9') which is designed to apply a pressure which is increased compared to the reduced pressure to a radially outer side of the labyrinth seal (20, 20').

15. Separating device (5, 5') according to claim 14, wherein the increased pressure is higher than the pressure in the first region (B1, BT).

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