EP3628411B1 - Screen star for a screening device - Google Patents
Screen star for a screening device Download PDFInfo
- Publication number
- EP3628411B1 EP3628411B1 EP19197319.7A EP19197319A EP3628411B1 EP 3628411 B1 EP3628411 B1 EP 3628411B1 EP 19197319 A EP19197319 A EP 19197319A EP 3628411 B1 EP3628411 B1 EP 3628411B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- fingers
- screening
- star
- taper
- stars
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000012216 screening Methods 0.000 title claims description 108
- 239000000463 material Substances 0.000 claims description 31
- 239000004033 plastic Substances 0.000 claims description 18
- 229920003023 plastic Polymers 0.000 claims description 18
- 241000826860 Trapezium Species 0.000 claims description 2
- 230000007704 transition Effects 0.000 description 29
- 238000004140 cleaning Methods 0.000 description 18
- 230000015572 biosynthetic process Effects 0.000 description 7
- 239000002245 particle Substances 0.000 description 5
- 229920001971 elastomer Polymers 0.000 description 4
- 230000001154 acute effect Effects 0.000 description 3
- 239000007769 metal material Substances 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 230000002787 reinforcement Effects 0.000 description 3
- 239000002689 soil Substances 0.000 description 3
- 230000004323 axial length Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 101100110009 Caenorhabditis elegans asd-2 gene Proteins 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000013590 bulk material Substances 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 239000002361 compost Substances 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 244000037666 field crops Species 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000002362 mulch Substances 0.000 description 1
- 239000003415 peat Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 230000003716 rejuvenation Effects 0.000 description 1
- 239000012858 resilient material Substances 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
- B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
- B07B1/12—Apparatus having only parallel elements
- B07B1/14—Roller screens
- B07B1/15—Roller screens using corrugated, grooved or ribbed rollers
- B07B1/155—Roller screens using corrugated, grooved or ribbed rollers the rollers having a star shaped cross section
Definitions
- the invention relates to a screening star for a screening device for screening material to be screened.
- the invention also relates to a screening device with a plurality of shafts which are rotatably arranged next to one another and on which the screen stars according to the invention are arranged axially next to one another in such a way that the screen stars of adjacent shafts engage in one another in the manner of a comb.
- the material to be screened can be bulk material, in particular mixtures containing soil, such as field crops covered with soil, compost, bark mulch, peat and the like or, for example, building rubble.
- Star screens and screening devices are from EP 1 088 599 B1 and the EP 2 666 549 B1 known. These screening devices and screening stars have proven themselves for screening the materials to be screened. With screening devices of this type, however, cohesive components of the material to be screened, such as loamy and moist soil, first settle on the backs and in the foot areas of the sickle-shaped fingers and, starting from these spaces, also cover the facing, lateral faces of the screening stars. The so-called disc formation occurs. The screening effect suffers as a result, and the drive power to be applied increases. The electric drive draws more power. Eventually, the screening device may become clogged and the drive may switch off due to overload.
- the DE 195 00 022 A1 discloses a screening device for screening bulk materials that are difficult to screen.
- the screening device consists of several parallel, driven shafts on which non-rotatable screen star disks with elastically flexible fingers are arranged.
- Two of the mirror-symmetrical, truncated cone-like screen star disks are joined together at their two large truncated cone bases and thereby form a screen star, so that several screen stars are arranged next to one another on each screen shaft in a rotationally fixed manner.
- star wheels for star wheel rollers of conveyor or trend devices.
- the star wheels which are essentially made of plastic have star-shaped protruding fingers on one hub part. Furthermore, the star wheels, at least in the area of the fingers, are provided with shaped structures which are predetermined by weight and load-optimized effective parameters.
- the US 5,975,441A discloses an apparatus for separating stones from stony material, such as earthen material.
- the device comprises a number of spiked rollers, each of which has a number of detachable spikes.
- the detachable spikes are staggered with respect to the spikes of an adjacent spiked roller so that as the spiked roller rotates, each spike can rotate through the gap between two spikes of the adjacent spiked roller and smaller rocks can fall through the gap between the spikes.
- An agricultural separator with star shafts, each having a plurality of resilient star wheels is in DE 697 01 393 T2 disclosed. Rings made of resilient material are fitted between the star wheels of the star shafts, which ensure better deformability to facilitate the self-cleaning of the star shaft.
- the subject matter of the invention is a screen star for a screening device, which comprises a hub for arranging the screen star on or on a rotatable shaft and a plurality of elastically flexible fingers, which protrude radially outwards from the hub and are distributed in the circumferential direction about an axis of rotation of the screen star.
- the respective finger extends radially and also in the circumferential direction, for example in the shape of a sickle, up to a free end trailing in the direction of rotation.
- the fingers can be made of rubber or, in particular, an elastomeric plastic such as a polyurethane (PU) plastic.
- the rubber or polymer can contain reinforcement particles, for example reinforcement fibers or also larger reinforcement structures, and in principle also other particles to achieve certain material properties.
- the sieve star is an assembly unit, ie it can be assembled as a unit. Hub and fingers are molded together as a unit, ie not joined from several parts.
- the fingers each taper from the foot area in the direction of the free end and in circular-cylindrical sections concentric to the axis of rotation in the circumferential direction on at least one face.
- the fingers taper on both end faces in the longitudinal direction of the fingers.
- the fingers taper on both end faces in relation to a central cross-sectional plane of the sieve star, i.e. the end faces of the fingers taper at least in sections, preferably over the majority of their length and particularly preferably from the foot area to the respective free end, i.e. over the entire length of the respective finger, are inclined to the central cross-sectional plane.
- a taper in the circumferential direction can in principle only be realized on one end face of the sieve star, but in preferred embodiments the fingers taper in the circumferential direction on both end faces.
- a two-sided taper in the longitudinal direction of the respective finger causes the meshing star screens of adjacent shafts to no longer form pairs of screen gaps with axially facing, parallel end faces, which promotes disc formation in conventional screening devices.
- the neighboring screen stars which each form a lateral screen gap with each other, only come closest to each other via the lateral screen gap along a line or a narrow strip and no longer over the entire surface.
- the space laterally between the axially adjacent screen stars widens from a narrowest, linear or at most strip-shaped screen gap in the circumferential direction.
- the axial, i. H. Pressing forces exerted laterally on the material to be screened decrease from the linear screen gap in the circumferential direction of the screen stars. Cohesive or other components of the material to be screened are no longer rubbed or ground to a large extent on the mutually facing end faces of the screen stars.
- a tapering in the circumferential direction on at least one end face has the result that the meshing star screens of adjacent shafts come closest to each other in the area of their axially facing end faces only linearly or in the area of a narrow strip, but no longer over the entire surface. This applies when the fingers each have only one taper in the circumferential direction.
- the fingers are tapered both in the longitudinal direction of the fingers and in the circumferential direction there are only punctiform constrictions, ie the space laterally between the axially adjacent sieve stars widens from one or possibly two punctiform constrictions in the circumferential direction.
- the fingers When tapering along the fingers, the fingers are designed in such a way that they progressively taper radially outwards in the longitudinal direction of the fingers on both end faces of the sieve star.
- the adhesion of cohesive material to be screened is thus counteracted on both end faces, for example also when a sieve star which is tapered according to the invention interacts with a simple disk-shaped sieve star on one or optionally also on both end faces.
- the fingers taper, starting from their foot regions, in the longitudinal direction of the fingers in each longitudinal section of the finger. In modifications, however, they can also taper only in a circular ring extending around the axis of rotation in the longitudinal direction of the fingers, then preferably starting directly from the foot area and/or up to an enveloping circle of the sieve star.
- the fingers which according to the invention taper in circular-cylindrical cuts concentric to the axis of rotation in a circumferential direction on at least one end face, can taper in the circumferential direction on both end faces of the sieve star.
- the fingers can be tapered in the direction of the front and/or in the direction of the back of the respective finger.
- a taper in the circumferential direction can be realized over the entire length of the respective finger, ie in all circular-cylindrical sections of the fingers.
- the tapering in the circumferential direction can also be realized only in a radially outer end region encompassing the free end or only in the foot region.
- the fingers can be tapered in the circumferential direction from the front to the back of the respective finger or at least over the majority of their circumferential extent measured in the respective section.
- the taper in the longitudinal direction of the fingers and/or the taper in the circumferential direction can be in relation to an axially central cross-sectional plane of the sieve star basically be designed asymmetrically, but the tapering along the fingers and/or the tapering against the direction of rotation preferably takes place symmetrically to the central cross-sectional plane.
- the fingers taper in the longitudinal direction of the fingers with a constant angle of inclination to a radial cross-sectional plane, in preferred embodiments over the entire extension of the fingers. Accordingly, the end faces each form a conical surface in the tapering area. Accordingly, the lateral screening gaps, i.e. the lateral narrow points, of a screening device equipped with screening stars that are conical on both sides are straight.
- the angle of inclination can also vary in other variants along the fingers.
- the angle of inclination measured on a radial cross-sectional plane can increase on one or advantageously on both end faces in the longitudinal direction of the respective finger towards the free end, so that the fingers are convex in shape on the end face in question.
- the angle of inclination can decrease outwards on one or advantageously on both end faces in the longitudinal direction of the respective finger, so that the fingers are concavely shaped on the end face in question.
- sieve stars with a convex end face on both sides and sieve stars with a concave end face on both sides can mesh in an axially alternating sequence.
- first shafts can have, for example, star screens each with convex end faces and second shafts can have star screens each with concave end faces, and the first shafts and the second shafts can be arranged alternately next to one another.
- the lateral sieve gaps are no longer straight in such a sieve device, so that elongate, slender particles to be sieved can fall through the lateral sieve gaps more or less only in the direction of their longitudinal extension.
- the fingers of the sieve star each have a front surface pointing in the direction of rotation on their front side and a rear surface pointing against the direction of rotation on their back side Surface, a left face, a right face, and front and rear transitions.
- the front transitions namely a left transition and a right transition, connect the two end faces with the front surface.
- the rear transitions namely a left transition and a right transition, connect the two front surfaces with the rear surface.
- the front transitions and/or the rear transitions are each curved at a radius of curvature of at least 1.5 mm or at least 2 mm.
- the transitions are usually edge-shaped, each with a significantly smaller radius of curvature of less than 1 mm.
- Softly rounded transitions for example, also counteract the adhesion of cohesive screenings components.
- Softly rounded rear transitions are particularly advantageous, since the adhesion of material to be screened usually begins on the rear surfaces of the fingers and from there progresses radially outwards and also axially to the sides. Edged, almost right-angled transitions favor the formation of discs, whereas the screenings in the area of the softly rounded transitions are more likely to be carried away by the neighboring sieve star.
- the fingers can each have a convex shape on their front side pointing in the direction of rotation and/or on their back side pointing counter to the direction of rotation with respect to the axial direction, for example roundly bulging outwards with respect to the axial direction or be arrow-shaped.
- the two flat sides running towards one another in the shape of an arrow advantageously merge into one another in the axially central surface area with a radius of curvature of at least 1.5 mm or at least 2 mm.
- each of the two ideas according to the invention counteracts the adhesion of screening material components on at least one end face. Also the embodiment with softly rounded front and/or rear transitions counteracts the adhesion of screenings components, in particular in combination with the two ideas according to the invention.
- the fingers do not taper off at their free ends, but instead have an end width B E measured axially of more than 5 mm or more than 7 mm.
- the end width B E is preferably in the range of 15 ⁇ 10 mm.
- the fingers can have an axially measured foot width B F of more than 12 mm or more than 15 mm.
- a foot width B F in the range of 26 ⁇ 14 mm is preferred.
- the ratio of foot width to end width, B F /B E can be 1.5 or greater, for example, but is at most 2.5 or preferably less in advantageous embodiments.
- the gap width of the lateral screen gaps can be determined in particular by an axial overhang of the hub over the foot area of the fingers.
- the hub can have a collar running around the axis of rotation, which protrudes over the finger foot area by the axial overhang.
- a collar is expediently present on both end faces.
- the overhang of the respective collar is more than 0.5 mm or at least 1 mm; the overhang is preferably selected from the range of 7 ⁇ 6 mm or 7 ⁇ 3 mm.
- the fingers each have a rotationally-facing front surface, an anti-rotationally-facing rear surface, an outer left face, an outer right face, front transitions connecting the front surfaces to the front surface, and rear transitions, connecting the end surfaces to the rear surface, the front transitions and/or the rear transitions each being curved at a radius of curvature of at least 1.5 mm or at least 2 mm.
- the fingers taper over at least a predominant part of their length, measured from the foot area to the free end, on both end faces in a continuously differentiable manner.
- the fingers can each taper in the direction of the free ends in an axial view of an end face of the screen star.
- the fingers can progressively taper outwards on both end faces of the screen star in the radial direction.
- the fingers on both end faces of the screen star can progressively taper outwards in the direction of the free end of the respective finger in relation to a cross-sectional plane of the screen star.
- the fingers can progressively taper outwards on both end faces of the sieve star in the direction of the free end of the respective finger without kinks.
- the fingers on both end faces of the sieve star taper conically progressively outwards in the direction of the free end of the respective finger with a constant angle of inclination.
- the fingers can each have a front side pointing in the direction of rotation, a back side pointing counter to the direction of rotation, a left-hand end face and a right-hand end face, with the end faces running towards one another in the circumferential direction over at least the majority of their circumferential extension, so that the fingers in the circular-cylindrical sections each taper in the circumferential direction.
- the fingers in circular-cylindrical sections concentric to the axis of rotation can each have a front side pointing in the direction of rotation, a rear side pointing counter to the direction of rotation, a left-hand end face and a right-hand end face, the end faces in the circular-cylindrical sections converging in the shape of arrows.
- the fingers are elongated in a circular or elliptical shape in circular-cylindrical sections concentric to the axis of rotation. Irrespective of this, the fingers can each taper in circular-cylindrical sections concentric to the axis of rotation over at least the predominant part of their circumferential extent in the circumferential direction.
- the fingers of the sieve star according to the invention each have a front side pointing in the direction of rotation, a rear side pointing against the direction of rotation, a left end face and a right end face in circular-cylindrical sections concentric to the axis of rotation, and in the circular-cylindrical sections the front side in the direction of rotation and /or the back is or are arrow-shaped against the direction of rotation.
- the front and/or the back can have a left flat side and a right flat side and the flat sides can converge in the shape of an arrow.
- the flat sides are flat or rounded outwards.
- the fingers each have a rotationally facing front surface, an anti-rotational rear surface, an outer left face, and an outer right surface, with the front and/or the rear surface being or being convex.
- the front side can be curved outwards in the direction of rotation and/or the back side against the direction of rotation.
- the hub can consist of a harder material than the fingers, for example a metal material or a harder plastic or rubber material.
- the hub and the fingers are each formed from a plastic material, the plastic material being filled with an additive which reduces fretting in the region of the free ends of the fingers.
- the fingers are made of an elastomeric plastics or rubber material optionally filled with reinforcing material.
- the fingers of the sieve star according to the invention advantageously have a width B F axially in a foot area and a width B E at the free end, with B F /B E being at least 1.5 and at most 2.5, preferably 1.8 ⁇ 0.2.
- the sieve star can have a maximum axial width B N in the area of the hub and the fingers can have a maximum axial width BF in the foot area, with B N /B F being at least 1.5 and at most 2.5, preferably 1.8 ⁇ 0.3.
- the sieve star can have a maximum axial width B N in the area of the hub and the fingers can each have a width B E at the free end, with B N /B E being at least 2 and at most 4, preferably 3.2 ⁇ 0.4 .
- a flight circle of the sieve star or an enveloping circle placed radially on the outside at the free ends of the fingers has a diameter of at least 150 mm and at most 300 mm, preferably 190 ⁇ 40 mm.
- a finger foot circle of the screen star or an outer circumference of the hub can have a diameter of at least 50 mm and at most 200 mm, preferably 100 ⁇ 30 mm.
- the hub on both end faces of the sieve star has a collar around the axis of rotation of the sieve star, which protrudes axially by at least 1 mm and at most 12 mm, preferably 7 ⁇ 3 mm, over the fingers.
- the hub of the screen star may have a central axial passage with a non-circular cross-section, preferably with at least one flat side, for non-rotating mounting on the shaft.
- a radial gap width over an axial length of the respective frontal screening gap is at least 2 mm and at most 12 mm, preferably 6 ⁇ 2 mm.
- a lateral gap width can be along the respective lateral screen gap everywhere at least 1 mm and at most 10 mm, preferably 4 ⁇ 2 mm.
- the screening device comprises a drive device for driving the shafts in rotation, with the drive device being set up to drive adjacent shafts at the same speed.
- the screening device can comprise a drive device for rotating the shafts, the drive device being set up to vary the speed of at least one of the shafts during operation of the device relative to the speed of an adjacent shaft.
- the Figures 1 and 2 show a screen star 1, as is known from the prior art, in an axial view of an end face and in a perspective view for better understanding of the invention.
- the sieve star 1 has a hub 2 and a plurality of fingers 5a distributed over the circumference of the hub 2, which protrude outwards from the outer circumference of the hub 2 in the radial direction R, starting from foot areas 6, and in the circumferential direction T and thereby counter to the direction of rotation of the sieve star 1 crescent-shaped bent inward to a free end 7 extend.
- the circumferential direction T entered is the direction of rotation of the sieve star 1.
- the free ends 7 are trailing ends.
- circumferential direction covers the direction of rotation and the opposite direction in equal measure, while when using the term “direction of rotation” a distinction is to be made between these two circumferential directions.
- the fingers 5a can be bent elastically and are therefore flexible. They are made of a plastic material.
- the hub 2 can be formed from the same plastic material or from a different, then expediently harder, plastic material.
- the hub 2 has a passage 3 in the central area for the arrangement on the shaft.
- the passage 3 is formed as a multi-flat in order to connect the sieve star 1 in a form-fitting manner to the shaft so that it cannot rotate.
- the hub 2 can have an insert made of a metal material in a central area for a rotationally immovable arrangement on a rotationally drivable shaft. more preferably, however, the plastic in the area of the hub 2 is sufficiently strong and hard so that such an insert can be dispensed with.
- the hub 2 has a collar 4 which protrudes axially over the fingers 5a and runs around a central axis of rotation D of the sieve star 1 .
- the hub 2 On the other end of the star screen 1, the hub 2 has a collar 4 of the same type.
- the outer circumference of the collar 4 on both sides is at the same time the outer circumference of the hub 2.
- the fingers 5a project outwards practically directly from the outer circumference of the collar 4, so that the foot areas 6 of the fingers 5a extend almost to the outer circumference of the hub 2 or the collar 4 enough.
- the outer circumference of the collar 4 can be regarded as the circle of the feet of the fingers 5a.
- One of the fingers 5a serves as a cleaning finger.
- a cleaning element 9 made of a metal material is supported on the front side of this cleaning finger 5a.
- the cleaning element 9 of the respective screening star 1 acts as a scraper, which removes material adhering to the axially adjacent screening stars 1 and one or the two scrapes adjacent shafts and thereby contributes to the screen gaps not clogging.
- the cleaning finger 5a is not crescent-shaped, but rather extends at least essentially straight in the radial direction R and counter to the direction of rotation T and, measured in the circumferential direction T, has a greater thickness than the other fingers 5a.
- Advantageous configurations for the combination of cleaning finger 5a and cleaning element 9 are, for example, in FIG EP 1 088 599 B1 described.
- the hub 2 When rotating about the axis of rotation D, the free ends 7 of all fingers 5a and also the free end of the cleaning element 9 revolve around an enveloping circle with the diameter D H .
- the hub 2 has an outer circumference with a diameter D N which, in the context of the invention, is regarded as the diameter of the root circle of the fingers 5a.
- the diameter D H is selected from the range of 150 mm to 250 mm, preferably 150 mm to 230 mm.
- the diameter DN is selected from the range of 50 mm to 200 mm, preferably 70 mm to 130 mm.
- the radial extension of the fingers 5a is from the range of 50 mm to 180 mm, preferably 80 mm to 120 mm. These are just examples of preferred size ranges. The invention is also advantageous for other diameter ranges.
- the fingers 5a each have, with respect to the direction of rotation, a front or front surface 10, a rear or rear surface 11, a left face 12 and a right face 13, and connecting transitions 14 at the front 10 and connecting transitions 15 at the rear 11 .
- the transitions 14 and 15 are softly rounded by connecting the respective end faces 12 and 13 to the front surface 10 and the rear surface 11 with a radius of curvature of 1.5 mm or more, preferably 2 mm or more. By avoiding sharp edges at the respective transition 14 and 15, the adhesion of cohesive screenings components is counteracted.
- the fingers 5a and also the cleaning finger 5a each taper progressively from the foot region 6 in the direction of the free end 7, ie they taper in the longitudinal direction L of the respective finger 5a in the cuts CC. This results in favorable conditions with regard to the desired elastic flexibility along the fingers 5a on the one hand with sufficient stability in the respective foot area 6 on the other.
- the narrowing along the fingers 5a is accompanied by a narrowing also in the radial direction R and thus in the longitudinal sections of the sieve star 1 containing the axis of rotation D. In figure 1 a longitudinal section AA is entered.
- the fingers 5a In circular-cylindrical sections BB concentric to the axis of rotation D, ie in the circumferential direction T, the fingers 5a have a constant width, measured axially, apart from a convexly rounded front end section and a convexly rounded rear end section.
- FIG 3 is the sieve star 1 in the section AA of the figure 1 shown.
- Section AA shows the course of the longitudinal direction of the finger L ( figure 1 ) progressive rejuvenation recognizable.
- the tapering occurs symmetrically on both end faces in relation to an axially central cross-sectional plane Q.
- the taper is formed in such a way that a symmetrical trapezoid with a radially inner long base in the finger foot region 6 and a comparatively shorter outer base at the free end 7 results in the sections AA for each of the fingers 5a.
- the two inclined end faces 12 and 13 enclose an acute angle with one another.
- the fingers 5a taper in the radial direction R directly from the base circle or the base regions 6 to the enveloping circle or the free ends 7.
- the cross-sectional plane Q forms the bisector.
- the angle of inclination ⁇ measured on it is at least 3° or at least 4° and preferably at most 20° or at most 16°.
- the taper runs over a greater length, but otherwise analogously to the taper in section A-A, so that the end faces 12 and 13 in sections CC are at an angle of inclination that is slightly smaller than the angle ⁇ is to run into each other.
- the end faces 12 and 13 each run along the fingers 5a from the foot area 6 to the free end 7 in a monotonous and continuously differentiable manner.
- the fingers 5a taper in the longitudinal direction L of the fingers in each length section.
- the cleaning finger 5a corresponds to the other fingers 5a in terms of taper.
- the cleaning finger 5a thus tapers in the longitudinal direction of the cleaning finger 5a and radially outwards, each symmetrically to the central cross-sectional plane Q.
- figure 4 shows one of the fingers 5a in section BB.
- the end faces 12 and 13 of the fingers 5a are parallel in the circular-cylindrical sections BB concentric with the axis of rotation D.
- the front surface 10 and the rear surface 11 are convex and curve outwards uniformly and round over the entire width of the respective finger 5a in the respective section BB. As in the exemplary embodiment, they can be bulged with a constant radius.
- the transitions 14 and 15 are not angular but softly rounded, with the respective radius of curvature being smaller than the radius of the surfaces 10 and 11 and advantageously being at least 1.5 mm or 2 mm or more.
- figure 5 is a radial view of the outer circumference of the screen star 1 of the first embodiment. It can be seen that the fingers 5a and also the cleaning finger 5a each taper progressively from the foot area 6 in the direction of the free end 7 .
- the hub width B N is selected from the range of 25 mm to 40 mm, preferably 30 mm to 40 mm.
- the root circle width B F is selected from the range of 12 mm to 25 mm, preferably 15 mm to 22 mm.
- the end width B E is selected from the range of 5 mm to 20 mm, preferably 7 mm to 15 mm. These are just examples of preferred size ranges. The invention is also advantageous for other width ranges.
- Figures 6 and 7 each show a portion of a screening device with screening stars of the first embodiment.
- figure 7 shows the partial area in an axial view of one end face of the sieve stars 1.
- figure 6 shows the same section in section EE figure 7 , in which the axes of rotation of the shafts 20 extend.
- the screening device has a plurality of rotationally drivable shafts 20 which are arranged next to one another and along which a plurality of screening stars 1 are arranged next to one another.
- the sieve stars 1 are mounted on the shafts 20 and secured against rotation.
- the sieve stars 1 of adjacent shafts 20 engage with each other with their fingers 5a in the manner of a comb, so that the sieve stars 1 of one shaft 20 and the sieve stars 1 of the adjacent shaft 20 alternately form lateral sieve gaps 21 and frontal sieve gaps 22 in the longitudinal direction of the shaft, which in plan view are common result in a coherent screen gap 21, 22 which meanders in the axial direction.
- the mutually facing end faces of intermeshing star screens 1 delimit the lateral sieve gaps 21.
- the free ends 7 of the sieve stars 1 delimit the frontal sieve gaps 22 with the radially facing, outer peripheral surfaces of the collars 4 of the sieve stars 1 of the respectively adjacent shaft 20.
- the lateral screen gaps 21 each have a narrowest screen gap, strip-shaped in section EE, with a gap width Ws, corresponding to the conical taper of the screen stars 1 .
- the narrowest screen gap is linear in the circumferential direction of the screen stars 1 .
- the front screen gaps 22 each have between the free end 7 and the outer Circumferential surface of the two collars 4 a narrowest screen gap with a radial gap width W R on.
- the gap widths W R and Ws largely determine the fineness of the star screen formed by the screen stars 1 . Due to the tapering in the longitudinal direction of the fingers 5a, the axial length of the frontal screen gaps 22 is reduced in comparison to simply disc-shaped screen stars 1 of the same material and the same stability.
- figure 8 shows a portion of a screening device with shafts 20 along which screening stars 1 of a second embodiment are arranged.
- the sieve stars 1 each have fingers 5b which extend in the longitudinal direction of the fingers 5b, ie in the longitudinal direction L ( figure 1 ), at a varying tilt angle ⁇ ( figure 3 ) are inclined in such a way that the fingers 5b are curved outwards on both end faces 12 and 13, forming a convex shape.
- the fingers 5b are flattened at the free ends 7, as in the first exemplary embodiment.
- You can average BB ( figure 1 ) correspond to the fingers 5a. Due to the meshing of convex sieve stars 1 of the shafts 20 with likewise convex sieve stars 1 of adjacent shafts 20, lateral sieve gaps 21 with punctiform constrictions Ep are formed.
- the screening device can alternately have first shafts 20 with screening stars 1 of the first exemplary embodiment and second shafts 20 with screening stars 1 of the second exemplary embodiment. Also in such modifications, in which conically tapered screen stars 1 mesh with convexly tapered screen stars 1, punctiform constrictions result for the lateral screen gaps 21.
- figure 9 shows a portion of a screening device with the known from the prior art screening stars 1 with fingers 5b and screening stars 1 with fingers 5c modified again.
- the screen stars 1 with the fingers 5b are on a shaft 20 axially next to each other arranged, and the screen stars 1 with the fingers 5c are arranged on an adjacent shaft 20 axially side by side.
- the sieve stars with the fingers 5c only one sieve star 1 is shown as representative of the others.
- the screening stars 1 engage with the fingers 5c like a comb in the screening stars 1 with the fingers 5b of the neighboring shaft.
- the fingers 5c are in finger longitudinal direction L ( figure 1 ) at a varying tilt angle ⁇ ( figure 3 ) tapers in such a way that the sieve stars 1 are curved inwards in the area of the fingers 5c on both end faces, whereby the relevant sieve star 1 in the area of the fingers 5c tapers concavely in the direction of the free end 7 of the respective finger 5c.
- the fingers 5c are flattened as in the first embodiment.
- You can average BB ( figure 1 ) correspond to the fingers 5a.
- figure 10 shows examples of modified fingers 5d to 5g, each of which differs in terms of the cross-sectional shape in the circular-cylindrical sections BB concentric to the axis of rotation D.
- the fingers 5d to 5g are in the direction of the free end of the respective finger, ie in the longitudinal direction of the finger L ( figure 1 ), tapered and can correspond to the fingers 5a or the fingers 5b or the fingers 5c with respect to the taper in the longitudinal direction L in particular and replace the respective type of finger within a screening device.
- the finger 5d has the shape of a rectangle in section B-B. It differs from the finger 5a of the first exemplary embodiment only in that the front surface 10 and the rear surface 11 are also straight in the respective section B-B.
- the finger 5e corresponds to the finger 5a of the first exemplary embodiment in the area of the front surface 10 and the two end faces 12 and 13, but is convex in the shape of an arrow on the rear surface 11 in contrast thereto.
- the finger 5f has two parallel faces 12 and 13, an arrow-shaped convex front surface 10 and an arrow-shaped convex rear surface 11 in section B-B.
- the finger 5g has parallel end faces 12 and 13 over about half of its circumferential extent, a rear surface 11 orthogonal thereto and straight in section B-B and a front surface 10 semi-oval, for example circular or elliptical, in section B-B.
- a sieve star 1 according to the invention is shown.
- the screening star 1 differs from the screening star 1 known from the prior art with regard to the shape of the circular-cylindrical cross-section BB concentric to the axis of rotation D and otherwise corresponds to the first exemplary embodiment.
- the fingers of the sieve star 1 are designated as fingers 5h to distinguish them from the fingers of the exemplary embodiments explained above.
- a cleaning finger as in the first exemplary embodiment, is not shown. This is due to the fact that the cleaning element 9 ( figure 1 ) is attached only after the forming of the screen star 1 forming plastic body and figure 11 shows the sieve star 1 before the cleaning element 9 is attached.
- the fingers 5h taper from the foot area 6 in the direction of the free end 7, i.e. in the longitudinal direction L of the fingers, like the fingers 5a of the first exemplary embodiment. Unlike the fingers 5a, however, the fingers 5h also taper over at least the majority of their circumferential extension measured in the circumferential direction T.
- figure 12 shows the in figure 11 registered cut BB.
- the circumferential direction T coincides with the direction of rotation of the sieve star 1 and is in figure 12 also registered.
- the fingers 5b have the shape of a trapezium, in which the front surface 10 pointing in the direction of rotation forms the long base and the rear surface 11 pointing against the direction of rotation forms the short base.
- the fingers 5h taper in the circumferential direction T, in the fourth exemplary embodiment counter to the direction of rotation T, on both end faces symmetrically, so that the trapezoidal shape is obtained in section BB.
- the front surface 10, the rear surface 11 and the two end faces 12 and 13 are each straight in section BB.
- transitions 14 and 15 extend over comparatively large radii of curvature into each other.
- the end faces 12 and 13 each enclose an acute angle 2 ⁇ in the sections BB, the bisector of which is the central cross-sectional plane Q.
- the angle of inclination ⁇ relative to the radial section plane Q is at least 4° or at least 5°.
- the angle of inclination ⁇ is preferably at most 15° or at most 10°.
- the sieve star 1 of the fourth exemplary embodiment can also be convex in accordance with the second exemplary embodiment or tapered concavely in accordance with the third exemplary embodiment in relation to the taper in the finger longitudinal direction L.
- FIG 15 shows examples of further modified fingers 5i to 5m, each of which differs in terms of the cross-sectional shape in the circular-cylindrical sections BB concentric to the axis of rotation D.
- the fingers 5i to 5m are in the direction of the free end of the respective finger, ie in the longitudinal direction L ( figures 1 and 11 ), tapered and can correspond to the fingers 5a or 5h or instead to the fingers 5b or the fingers 5c in relation to the taper in the longitudinal direction L and can replace the respective type of finger within a screening device. They differ from the fingers 5a and 5d to 5g in that they taper in the circumferential direction T over at least the majority of their circumferential extent, corresponding to the finger 5h.
- the finger 5i is derived from the finger 5h of the fourth exemplary embodiment and differs from it in that the front surface 10 and the rear surface 11 are each convexly curved over the entire width of the finger 5d.
- the finger 5j is triangular in section B-B, with the "point" of the triangle trailing in the direction of rotation T.
- the finger 5k has, in section B-B, an arrow-shaped front surface 10, an axially extending rear surface 11 and two straight end faces 12 and 13 which taper towards one another at an acute angle against the direction of rotation T.
- the finger 51 is diamond-shaped in section B-B with two end faces 12 and 13, which run from a circumferentially central, wide area in the direction of rotation T to the front surface 10, which is only designed as a "tip”, and also counter to the direction of rotation T to the also only as "Pointed" trained rear surface 11 run.
- the finger 51 is as a result in both circumferential directions, i. H. in the direction of rotation T and against the direction of rotation T, tapered in the shape of an arrow.
- the finger 5m is oval in section B-B, e.g. elliptical, with the extent in the circumferential direction T greater than the axial extent, i. H. larger than the width.
- the oval shape for example an elliptical shape, is favorable in view of the wear that occurs during operation and also because of the constriction that forms in the lateral screen gap in a punctiform manner for reducing the adhesion of cohesive screenings components.
- the transitions between the surfaces 10 to 13 are each represented as edges. In preferred embodiments, however, these fingers are also softly rounded at the relevant transitions with a radius of curvature of at least 1.5 mm or, preferably, at least 2 mm.
- figure 16 shows meshing star screens 1 of the first exemplary embodiment in a relative rotational position to one another, in which just one finger 5a of one sieve star 1 is in maximum overlap with a finger 5a of the other sieve star 1. Due to the taper at least essentially in the longitudinal direction L of the fingers 5a is formed between the two overlapping fingers 5a a linear constriction E L . The lateral screen gap existing between the momentarily overlapping fingers 5a widens upwards and downwards, starting from the constriction E L . This design of the screen gaps counteracts the adhesion of cohesive screened material components and thus the so-called disc formation. This reduces the drive power required to operate the screening device.
- FIGs 17 and 18 show two meshing star screen 1 of the fourth embodiment.
- the cooperating screen stars 1 just take a rotational position in which a finger 5h of a screen star 1 has a slight overlap with one of the fingers 5h of the other screen star 1.
- E P punctiform constriction
- the sieve stars 1 continue to rotate, the overlap increases.
- Two punctiform constrictions form E P , which, starting from the state of the initial overlap, migrate in the direction of the two free ends of the overlapping fingers 5h. This turning state is in figure 18 shown. If the relevant fingers 5h dip even further into the overlap, the axial width ( figure 6 ) of the lateral screen gap existing between these two fingers 5h. Due to the double taper and the resulting punctiform bottlenecks E P , the adhesion of cohesive screenings components and thus the formation of discs is counteracted even more effectively.
Landscapes
- Combined Means For Separation Of Solids (AREA)
Description
Die Erfindung betrifft einen Siebstern für eine Siebvorrichtung zum Sieben eines Siebguts. Die Erfindung betrifft auch eine Siebvorrichtung mit mehreren nebeneinander drehbar angeordneten Wellen, auf denen axial nebeneinander erfindungsgemäße Siebsterne so angeordnet sind, dass die Siebsterne benachbarter Wellen kammartig ineinandergreifen. Bei dem Siebgut kann es sich um Schüttgüter, insbesondere erdhaltige Gemische, wie etwa mit Erde behaftete Feldfrüchte, Kompost, Rindenmulch, Torf und dergleichen oder beispielsweise auch um Bauschutt, handeln.The invention relates to a screening star for a screening device for screening material to be screened. The invention also relates to a screening device with a plurality of shafts which are rotatably arranged next to one another and on which the screen stars according to the invention are arranged axially next to one another in such a way that the screen stars of adjacent shafts engage in one another in the manner of a comb. The material to be screened can be bulk material, in particular mixtures containing soil, such as field crops covered with soil, compost, bark mulch, peat and the like or, for example, building rubble.
Siebsterne und Siebvorrichtungen, sogenannte Sternsiebe, wie die Erfindung sie unter anderem betrifft, sind aus der
Die
In der
Die
Eine landwirtschaftliche Trennvorrichtung mit Sternwellen, welche jeweils mehrere federnde Sternräder aufweisen, wird in der
Es ist daher eine Aufgabe der Erfindung, dem Anhaften von Siebgutbestandteilen am Siebstern und dadurch einer Scheibenbildung entgegen zu wirken.It is therefore an object of the invention to counteract the adhesion of screenings components to the screening star and thus disc formation.
Die Erfindung hat dementsprechend einen Siebstern für eine Siebvorrichtung zum Gegenstand, der eine Nabe zur Anordnung des Siebsterns auf oder an einer drehbaren Welle und mehrere elastisch nachgiebige Finger umfasst, die in Umfangsrichtung um eine Drehachse des Siebsterns verteilt von der Nabe nach radial außen vorragen. Der jeweilige Finger erstreckt sich radial und auch in Umfangsrichtung, beispielsweise sichelförmig, bis zu einem in Drehrichtung nachlaufenden freien Ende. Die Finger können aus Gummi oder insbesondere einem elastomeren Kunststoff, wie etwa einem Polyurethan(PU)-Kunststoff, bestehen. Im Gummi oder Polymer können Verstärkungspartikel, beispielsweise Verstärkungsfasern oder auch größere Verstärkungsstrukturen, grundsätzlich auch andere Partikel zur Erzielung bestimmter Werkstoffeigenschaften, enthalten sein. Der Siebstern ist eine Montageeinheit, d.h. als Einheit montierbar. Nabe und Finger sind gemeinsam als Einheit geformt, d.h. nicht aus mehreren Teilen gefügt.Accordingly, the subject matter of the invention is a screen star for a screening device, which comprises a hub for arranging the screen star on or on a rotatable shaft and a plurality of elastically flexible fingers, which protrude radially outwards from the hub and are distributed in the circumferential direction about an axis of rotation of the screen star. The respective finger extends radially and also in the circumferential direction, for example in the shape of a sickle, up to a free end trailing in the direction of rotation. The fingers can be made of rubber or, in particular, an elastomeric plastic such as a polyurethane (PU) plastic. The rubber or polymer can contain reinforcement particles, for example reinforcement fibers or also larger reinforcement structures, and in principle also other particles to achieve certain material properties. The sieve star is an assembly unit, ie it can be assembled as a unit. Hub and fingers are molded together as a unit, ie not joined from several parts.
Nach der Erfindung verjüngen sich die Finger jeweils vom Fußbereich in Richtung auf das freie Ende und in kreiszylindrischen, zur Drehachse konzentrischen Schnitten in Umfangsrichtung an mindestens einer Strinfläche. Bei Verjüngung in Richtung auf das freie Ende verjüngen sich die Finger an beiden Stirnseiten in Fingerlängsrichtung. Dies bedeutet, dass sich die Finger an beiden Stirnseiten in Bezug auf eine zentrale Querschnittsebene des Siebsterns verjüngen, die Stirnflächen der Finger also zumindest abschnittsweise, vorzugsweise über den überwiegenden Teil ihrer Länge und besonders bevorzugt vom Fußbereich bis zum jeweiligen freien Ende, d h. über die gesamte Länge des jeweiligen Fingers, zur zentralen Querschnittsebene geneigt sind. Wenn im Folgenden davon die Rede ist, dass sich die Finger in Längsrichtung verjüngen, wird dieser Sachverhalt in verkürzter Form ausgedrückt. Eine Verjüngung in Umfangsrichtung kann zwar grundsätzlich an nur einer Stirnseite des Siebsterns verwirklicht sein, in bevorzugten Ausführungen verjüngen sich die Finger in Umfangsrichtung jedoch an beiden Stirnseiten.According to the invention, the fingers each taper from the foot area in the direction of the free end and in circular-cylindrical sections concentric to the axis of rotation in the circumferential direction on at least one face. When they taper towards the free end, the fingers taper on both end faces in the longitudinal direction of the fingers. This means that the fingers taper on both end faces in relation to a central cross-sectional plane of the sieve star, i.e. the end faces of the fingers taper at least in sections, preferably over the majority of their length and particularly preferably from the foot area to the respective free end, i.e. over the entire length of the respective finger, are inclined to the central cross-sectional plane. When it is mentioned below that the fingers taper in the longitudinal direction, this fact is expressed in an abbreviated form. A taper in the circumferential direction can in principle only be realized on one end face of the sieve star, but in preferred embodiments the fingers taper in the circumferential direction on both end faces.
Der erste erfindungsgemäße Gedanke, eine beidseitige Verjüngung in Längsrichtung des jeweiligen Fingers, bewirkt, dass die miteinander kämmenden Siebsterne benachbarter Wellen keine paarweisen Siebspalte mit axial einander zugewandten, parallelen Stirnflächen mehr bilden, wodurch bei herkömmlichen Siebvorrichtungen die Scheibenbildung begünstigt wird. Die benachbarten Siebsterne, die jeweils einen seitlichen Siebspalt miteinander bilden, kommen sich über den seitlichen Siebspalt nur noch längs einer Linie oder eines schmalen Streifens und nicht mehr vollflächig am nächsten. Der Raum seitlich zwischen den axial benachbarten Siebsternen verbreitert sich von einem engsten, linien- oder allenfalls streifenförmigen Siebspalt in Umfangsrichtung. Die von benachbarten Siebsternen axial, d. h. seitlich, auf das Siebgut ausgeübten Presskräfte nehmen vom linienhaften Siebspalt ausgehend in Umfangsrichtung der Siebsterne ab. Es kommt an den einander zugewandten Stirnseiten der Siebsterne nicht mehr oder weit weniger zu einem flächigen Verreiben oder Zerreiben bindiger oder anderer Bestandteile des Siebguts.The first idea according to the invention, a two-sided taper in the longitudinal direction of the respective finger, causes the meshing star screens of adjacent shafts to no longer form pairs of screen gaps with axially facing, parallel end faces, which promotes disc formation in conventional screening devices. The neighboring screen stars, which each form a lateral screen gap with each other, only come closest to each other via the lateral screen gap along a line or a narrow strip and no longer over the entire surface. The space laterally between the axially adjacent screen stars widens from a narrowest, linear or at most strip-shaped screen gap in the circumferential direction. The axial, i. H. Pressing forces exerted laterally on the material to be screened decrease from the linear screen gap in the circumferential direction of the screen stars. Cohesive or other components of the material to be screened are no longer rubbed or ground to a large extent on the mutually facing end faces of the screen stars.
Der zweite erfindungsgemäße Gedanke, eine Verjüngung in Umfangsrichtung an mindestens einer Stirnfläche, hat zur Folge, dass die miteinander kämmenden Siebsterne benachbarter Wellen sich im Bereich ihrer axial einander zugewandten Stirnseiten nur linienförmig oder im Bereich eines schmalen Streifens, aber nicht mehr vollflächig am nächsten kommen. Dies gilt, wenn die Finger jeweils nur eine Verjüngung in Umfangsrichtung aufweisen. Sind die Finger hingegen sowohl in Längsrichtung der Finger als auch in Umfangsrichtung verjüngt, bilden sich nur noch punktförmige Engstellen, d. h. der Raum seitlich zwischen den axial benachbarten Siebsternen verbreitert sich von einem oder gegebenenfalls zwei punktförmigen Engstelle(n) in Umfangsrichtung. Die von benachbarten Siebsternen axial auf das Siebgut ausgeübten Presskräfte nehmen von der oder den punktförmigen Engstelle(n) ausgehend ab. Dem Anhaften bindiger Siebgutbestandteile und somit einer Scheibenbildung wird bei Überlagerung beider Arten der Verjüngung noch wirksamer entgegengewirkt.The second idea according to the invention, a tapering in the circumferential direction on at least one end face, has the result that the meshing star screens of adjacent shafts come closest to each other in the area of their axially facing end faces only linearly or in the area of a narrow strip, but no longer over the entire surface. This applies when the fingers each have only one taper in the circumferential direction. On the other hand, if the fingers are tapered both in the longitudinal direction of the fingers and in the circumferential direction there are only punctiform constrictions, ie the space laterally between the axially adjacent sieve stars widens from one or possibly two punctiform constrictions in the circumferential direction. The pressing forces exerted axially on the material to be screened by adjacent screening stars decrease starting from the punctiform constriction(s). The adhesion of cohesive screenings components and thus the formation of discs is counteracted even more effectively when both types of tapering are superimposed.
Bei Verjüngung längs der Finger sind die Finger so gestaltet, dass sie sich in Fingerlängsrichtung nach radial außen fortschreitend an beiden Stirnseiten des Siebsterns verjüngen. Dem Anhaften bindigen Siebguts wird somit an beiden Stirnseiten entgegengewirkt, beispielsweise auch dann, wenn ein erfindungsgemäß verjüngter Siebstern an einer oder gegebenenfalls auch an beiden Stirnseiten jeweils mit einem einfach scheibenförmigen Siebstern zusammenwirkt. In vorteilhaften Ausführungen verjüngen sich die Finger von ihren Fußbereichen ausgehend in Fingerlängsrichtung in jedem Längsabschnitt des Fingers. In Modifikationen können sie sich aber auch nur in einem um die Drehachse erstreckten Kreisring in Fingerlängsrichtung verjüngen, dann bevorzugt unmittelbar vom Fußbereich ausgehend und/oder bis zu einem Hüllkreis des Siebsterns.When tapering along the fingers, the fingers are designed in such a way that they progressively taper radially outwards in the longitudinal direction of the fingers on both end faces of the sieve star. The adhesion of cohesive material to be screened is thus counteracted on both end faces, for example also when a sieve star which is tapered according to the invention interacts with a simple disk-shaped sieve star on one or optionally also on both end faces. In advantageous embodiments, the fingers taper, starting from their foot regions, in the longitudinal direction of the fingers in each longitudinal section of the finger. In modifications, however, they can also taper only in a circular ring extending around the axis of rotation in the longitudinal direction of the fingers, then preferably starting directly from the foot area and/or up to an enveloping circle of the sieve star.
Zweckmäßigerweise können sich die Finger, welche sich erfindungsgemäß jeweils in kreiszylindrischen, zur Drehachse konzentrischen Schnitten in eine Umfangsrichtung an mindestens einer Stirnfläche verjüngen, an beiden Stirnseiten des Siebsterns in Umfangsrichtung verjüngen. Die Finger können hierbei in Bezug auf die Drehrichtung in Richtung auf die Vorderseite und/oder in Richtung auf die Rückseite des jeweiligen Fingers verjüngt sein. Eine Verjüngung in Umfangsrichtung kann über die gesamte Länge des jeweiligen Fingers, also in allen kreiszylindrischen Schnitten der Finger, verwirklicht sein. Die Verjüngung in Umfangsrichtung kann aber stattdessen auch nur in einem das freie Ende umfassenden radial äußeren Endbereich oder nur im Fußbereich verwirklicht sein. Die Finger können von der Vorderseite bis zur Rückseite des jeweiligen Fingers oder wenigstens über den überwiegenden Teil ihrer im jeweiligen Schnitt gemessenen Umfangserstreckung in Umfangsrichtung verjüngt sein.Expediently, the fingers, which according to the invention taper in circular-cylindrical cuts concentric to the axis of rotation in a circumferential direction on at least one end face, can taper in the circumferential direction on both end faces of the sieve star. In relation to the direction of rotation, the fingers can be tapered in the direction of the front and/or in the direction of the back of the respective finger. A taper in the circumferential direction can be realized over the entire length of the respective finger, ie in all circular-cylindrical sections of the fingers. Instead, the tapering in the circumferential direction can also be realized only in a radially outer end region encompassing the free end or only in the foot region. The fingers can be tapered in the circumferential direction from the front to the back of the respective finger or at least over the majority of their circumferential extent measured in the respective section.
Die Verjüngung in Fingerlängsrichtung und/oder die Verjüngung in Umfangsrichtung kann oder können jeweils in Bezug auf eine axial zentrale Querschnittsebene des Siebsterns zwar grundsätzlich asymmetrisch gestaltet sein, bevorzugt erfolgt die Verjüngung längs der Finger und/oder die Verjüngung gegen die Drehrichtung jedoch symmetrisch zur zentralen Querschnittsebene.The taper in the longitudinal direction of the fingers and/or the taper in the circumferential direction can be in relation to an axially central cross-sectional plane of the sieve star basically be designed asymmetrically, but the tapering along the fingers and/or the tapering against the direction of rotation preferably takes place symmetrically to the central cross-sectional plane.
Die Finger verjüngen sich in Fingerlängsrichtung in ersten Varianten mit konstantem Neigungswinkel zu einer radialen Querschnittebene, in bevorzugten Ausführungen über die gesamte Erstreckung der Finger. Die Stirnflächen bilden im sich verjüngenden Bereich dementsprechend jeweils eine Konusfläche. Entsprechend sind die seitlichen Siebspalte, d.h. die seitlichen Engstellen, einer mit beidseits konischen Siebsternen bestückten Siebvorrichtung gerade.In first variants, the fingers taper in the longitudinal direction of the fingers with a constant angle of inclination to a radial cross-sectional plane, in preferred embodiments over the entire extension of the fingers. Accordingly, the end faces each form a conical surface in the tapering area. Accordingly, the lateral screening gaps, i.e. the lateral narrow points, of a screening device equipped with screening stars that are conical on both sides are straight.
Der Neigungswinkel kann stattdessen aber auch in anderen Varianten längs der Finger variieren. So kann der auf eine radiale Querschnittebene gemessene Neigungswinkel in zweiten Varianten an einer oder vorteilhafterweise an beiden Stirnseiten in Längsrichtung des jeweiligen Fingers zum freien Ende hin zunehmen, so dass die Finger an der betreffenden Stirnseite konvex geformt sind. Sind nebeneinander angeordnete Wellen einer Siebvorrichtung mit Siebsternen bestückt, die an beiden Stirnseiten jeweils konvexe, vorzugsweise nach außen rund gewölbte Stirnflächen aufweisen, wird im Raum seitlich zwischen miteinander kämmenden Siebsternen jeweils eine punktförmige Engstelle erhalten. In der Draufsicht auf ein derartiges Sternsieb verbreitern sich die seitlichen Siebspalten von der punktförmigen Engstelle aus. In dritten Varianten kann der Neigungswinkel an einer oder vorteilhafterweise an beiden Stirnseiten in Längsrichtung des jeweiligen Fingers nach außen abnehmen, so dass die Finger an der betreffenden Stirnseite konkav geformt sind. In einer Siebvorrichtung können Siebsterne mit beidseits konvexer Stirnseite und Siebsterne mit beidseits konkaver Stirnseite in axial alternierender Folge ineinandergreifen. In solch einer Siebvorrichtung können erste Wellen beispielsweise Siebsterne mit jeweils konvexen Stirnseiten und zweite Wellen Siebsterne mit jeweils konkaven Stirnseiten aufweisen und die ersten Wellen und die zweiten Wellen alternierend nebeneinander angeordnet sein. Die seitlichen Siebspalte sind in solch einer Siebvorrichtung nicht mehr gerade, so dass langgestreckt schlanke Siebgutpartikel quasi nur in Richtung ihrer Längserstreckung durch die seitlichen Siebspalte fallen können.Instead, the angle of inclination can also vary in other variants along the fingers. In second variants, the angle of inclination measured on a radial cross-sectional plane can increase on one or advantageously on both end faces in the longitudinal direction of the respective finger towards the free end, so that the fingers are convex in shape on the end face in question. If juxtaposed shafts of a screening device are equipped with screening stars, each of which has convex, preferably outwardly curved, end faces on both end faces, a punctiform constriction is obtained in the space laterally between meshing screening stars. In the top view of such a star screen, the lateral screen gaps widen from the point-like constriction. In third variants, the angle of inclination can decrease outwards on one or advantageously on both end faces in the longitudinal direction of the respective finger, so that the fingers are concavely shaped on the end face in question. In a sieve device, sieve stars with a convex end face on both sides and sieve stars with a concave end face on both sides can mesh in an axially alternating sequence. In such a screening device, first shafts can have, for example, star screens each with convex end faces and second shafts can have star screens each with concave end faces, and the first shafts and the second shafts can be arranged alternately next to one another. The lateral sieve gaps are no longer straight in such a sieve device, so that elongate, slender particles to be sieved can fall through the lateral sieve gaps more or less only in the direction of their longitudinal extension.
Die Finger des Siebsterns weisen jeweils an ihrer Vorderseite eine in Drehrichtung weisende vordere Oberfläche, an ihrer Rückseite eine gegen die Drehrichtung weisende rückwärtige Oberfläche, eine linke Stirnfläche, eine rechte Stirnfläche sowie vordere und hintere Übergänge auf. Die vorderen Übergänge, nämlich ein linker Übergang und ein rechter Übergang, verbinden die beiden Stirnflächen mit der vorderen Oberfläche. Die hinteren Übergänge, nämlich ein linker Übergang und ein rechter Übergang, verbinden die beiden Stirnflächen mit der rückwärtigen Oberfläche.The fingers of the sieve star each have a front surface pointing in the direction of rotation on their front side and a rear surface pointing against the direction of rotation on their back side Surface, a left face, a right face, and front and rear transitions. The front transitions, namely a left transition and a right transition, connect the two end faces with the front surface. The rear transitions, namely a left transition and a right transition, connect the two front surfaces with the rear surface.
Bei einer weiteren beispielhaften Ausführungsform sind die vorderen Übergänge und/oder die rückwärtigen Übergänge jeweils unter einem Krümmungsradius von wenigstens 1,5 mm oder wenigstens 2 mm gekrümmt. Üblicherweise sind die Übergänge kantenförmig mit jeweils einem deutlich kleineren Krümmungsradius von weniger als 1 mm. Durch beispielsweise weich gerundete Übergänge wird dem Anhaften bindiger Siebgutbestandteile ebenfalls entgegengewirkt. Besonders vorteilhaft sind weich gerundete rückwärtige Übergänge, da die Anhaftung von Siebgutmaterial zumeist an den rückwärtigen Oberflächen der Finger beginnt und von dort nach radial außen und auch axial zu den Seiten fortschreitet. Kantige, nahezu rechtwinkelige Übergänge begünstigen die Scheibenbildung, wohingegen das Siebgut im Bereich der weich gerundeten Übergänge vom benachbarten Siebstern eher mitgerissen wird.In a further exemplary embodiment, the front transitions and/or the rear transitions are each curved at a radius of curvature of at least 1.5 mm or at least 2 mm. The transitions are usually edge-shaped, each with a significantly smaller radius of curvature of less than 1 mm. Softly rounded transitions, for example, also counteract the adhesion of cohesive screenings components. Softly rounded rear transitions are particularly advantageous, since the adhesion of material to be screened usually begins on the rear surfaces of the fingers and from there progresses radially outwards and also axially to the sides. Edged, almost right-angled transitions favor the formation of discs, whereas the screenings in the area of the softly rounded transitions are more likely to be carried away by the neighboring sieve star.
Die Finger können jeweils an ihrer in Drehrichtung weisenden Vorderseite und/oder an ihrer gegen die Drehrichtung weisenden Rückseite in Bezug auf die Achsrichtung konvex geformt sein, beispielsweise in Bezug auf die Achsrichtung nach außen rund vorgewölbt oder pfeilförmig sein. Dies bedeutet, dass die vordere Oberfläche und/oder die rückwärtige Oberfläche des jeweiligen Fingers in den kreiszylindrischen, zur Drehachse konzentrischen Schnitten konvex ist oder sind, die vordere Oberfläche also in Drehrichtung und/oder die rückwärtige Oberfläche gegen die Drehrichtung konvex ist oder jeweils sind. Weist eine der beiden Oberflächen eine Pfeilform auf, so gehen die beiden pfeilförmig aufeinander zulaufenden Flachseiten vorteilhafterweise im axial zentralen Oberflächenbereich unter einem Krümmungsradius von wenigstens 1,5 mm oder wenigstens 2 mm rundgebogen ineinander über.The fingers can each have a convex shape on their front side pointing in the direction of rotation and/or on their back side pointing counter to the direction of rotation with respect to the axial direction, for example roundly bulging outwards with respect to the axial direction or be arrow-shaped. This means that the front surface and/or the rear surface of the respective finger is or are convex in the circular-cylindrical sections concentric to the axis of rotation, i.e. the front surface is convex in the direction of rotation and/or the rear surface is or are convex against the direction of rotation. If one of the two surfaces is arrow-shaped, the two flat sides running towards one another in the shape of an arrow advantageously merge into one another in the axially central surface area with a radius of curvature of at least 1.5 mm or at least 2 mm.
Dem Anhaften von Siebgutbestandteilen wirkt jeder der zwei erfindungsgemäßen Gedanken, die Verjüngung in Längsrichtung der Finger und die Verjüngung in Umfangsrichtung an mindestens einer Stirnfläche entgegen. Auch die Ausführungsform mit weich gerundeten vorderen und/oder rückwärtigen Übergängen wirkt dem Anhaften von Siebgutbestandteilen, insbesondere in der Kombination mit den zwei erfindungsgemäßen Gedanken, entgegen.Each of the two ideas according to the invention, the tapering in the longitudinal direction of the fingers and the tapering in the circumferential direction, counteracts the adhesion of screening material components on at least one end face. Also the embodiment with softly rounded front and/or rear transitions counteracts the adhesion of screenings components, in particular in combination with the two ideas according to the invention.
In vorteilhaften Ausführungen laufen die Finger an ihren freien Enden nicht spitz aus, sondern weisen dort eine axial gemessene Endenbreite BE von mehr als 5 mm oder mehr als 7 mm auf. Bevorzugt liegt die Endenbreite BE im Bereich von 15 ± 10 mm. Bei einer Verjüngung in Fingerlängsrichtung und einer Verjüngung in Umfangsrichtung an mindestens einer Stirnfläche können die Finger jeweils im Bereich des freien Endes axial am schmalsten sein.In advantageous embodiments, the fingers do not taper off at their free ends, but instead have an end width B E measured axially of more than 5 mm or more than 7 mm. The end width B E is preferably in the range of 15 ± 10 mm. With a taper in the longitudinal direction of the finger and a taper in the circumferential direction on at least one end face, the fingers can each be axially narrowest in the area of the free end.
Die Finger können im Fußbereich eine axial gemessene Fußbreite BF von mehr als 12 mm oder mehr als 15 mm aufweisen. Eine Fußbreite BF aus dem Bereich von 26 ± 14 mm wird bevorzugt. Bei Verjüngung in Fingerlängsrichtung und/oder Verjüngung in Umfangsrichtung kann das Verhältnis von Fußbreite zu Endenbreite, BF / BE, beispielsweise 1.5 oder größer sein, liegt in vorteilhaften Ausführungen aber höchstens bei 2.5 oder bevorzugt darunter.In the foot area, the fingers can have an axially measured foot width B F of more than 12 mm or more than 15 mm. A foot width B F in the range of 26 ± 14 mm is preferred. With tapering in the longitudinal direction of the finger and/or tapering in the circumferential direction, the ratio of foot width to end width, B F /B E , can be 1.5 or greater, for example, but is at most 2.5 or preferably less in advantageous embodiments.
Die Spaltweite der seitlichen Siebspalte kann insbesondere durch einen axialen Überstand der Nabe über den Fußbereich der Finger bestimmt werden. So kann die Nabe einen um die Drehachse umlaufenden Bund aufweisen, der um den axialen Überstand über den Fingerfußbereich vorragt. Zweckmäßigerweise ist ein derartiger Bund an beiden Stirnseiten vorhanden. Der Überstand des jeweiligen Bunds beträgt in vorteilhaften Ausführungen mehr als 0,5 mm oder wenigstens 1 mm, bevorzugt ist der Überstand aus dem Bereich von 7 ± 6 mm oder 7 ± 3 mm gewählt.The gap width of the lateral screen gaps can be determined in particular by an axial overhang of the hub over the foot area of the fingers. Thus, the hub can have a collar running around the axis of rotation, which protrudes over the finger foot area by the axial overhang. Such a collar is expediently present on both end faces. In advantageous embodiments, the overhang of the respective collar is more than 0.5 mm or at least 1 mm; the overhang is preferably selected from the range of 7±6 mm or 7±3 mm.
Auch in den nachstehend formulierten Ausführungsformen werden vorteilhafte Weiterbildungen der Erfindung nach Anspruch 1 beschrieben.Advantageous developments of the invention according to
Bei einer ersten beispielhaften Ausführungsform weisen die Finger jeweils eine in Drehrichtung weisende vordere Oberfläche, eine gegen die Drehrichtung weisende rückwärtige Oberfläche, eine äußere linke Stirnfläche, eine äußere rechte Stirnfläche, vordere Übergänge, die die Stirnflächen mit der vorderen Oberfläche verbinden, und rückwärtige Übergänge, die die Stirnflächen mit der rückwärtigen Oberfläche verbinden, auf, wobei die vorderen Übergänge und/oder die rückwärtigen Übergänge jeweils unter einem Krümmungsradius von wenigstens 1,5 mm oder wenigstens 2 mm gekrümmt sind.In a first exemplary embodiment, the fingers each have a rotationally-facing front surface, an anti-rotationally-facing rear surface, an outer left face, an outer right face, front transitions connecting the front surfaces to the front surface, and rear transitions, connecting the end surfaces to the rear surface, the front transitions and/or the rear transitions each being curved at a radius of curvature of at least 1.5 mm or at least 2 mm.
Bei einer weiteren beispielhaften Ausführungsform verjüngen sich die Finger jeweils über zumindest einen überwiegenden Teil ihrer vom Fußbereich bis zum freien Ende gemessenen Länge an beiden Stirnseiten stetig differenzierbar. Insbesondere können sich die Finger jeweils in einer axialen Sicht auf eine Stirnseite des Siebsterns in Richtung auf die freien Enden verjüngen.In a further exemplary embodiment, the fingers taper over at least a predominant part of their length, measured from the foot area to the free end, on both end faces in a continuously differentiable manner. In particular, the fingers can each taper in the direction of the free ends in an axial view of an end face of the screen star.
Die Finger können sich an beiden Stirnseiten des Siebsterns in radialer Richtung nach außen fortschreitend verjüngen.The fingers can progressively taper outwards on both end faces of the screen star in the radial direction.
Unabhängig davon können sich die Finger an beiden Stirnseiten des Siebsterns in Richtung auf das freie Ende des jeweiligen Fingers nach außen fortschreitend in Bezug auf eine Querschnittsebene des Siebsterns symmetrisch verjüngen.Irrespective of this, the fingers on both end faces of the screen star can progressively taper outwards in the direction of the free end of the respective finger in relation to a cross-sectional plane of the screen star.
Die Finger können sich an beiden Stirnseiten des Siebsterns in Richtung auf das freie Ende des jeweiligen Fingers nach außen fortschreitend knickfrei verjüngen.The fingers can progressively taper outwards on both end faces of the sieve star in the direction of the free end of the respective finger without kinks.
Bei einer weiteren beispielhaften Ausführungsform verjüngen sich die Finger an beiden Stirnseiten des Siebsterns in Richtung auf das freie Ende des jeweiligen Fingers mit konstantem Neigungswinkel konisch fortschreitend nach außen.In a further exemplary embodiment, the fingers on both end faces of the sieve star taper conically progressively outwards in the direction of the free end of the respective finger with a constant angle of inclination.
Die Finger können in kreiszylindrischen, zur Drehachse konzentrischen Schnitten jeweils eine in Drehrichtung weisende Vorderseite, eine gegen die Drehrichtung weisende Rückseite, eine linke Stirnfläche und eine rechte Stirnfläche aufweisen, wobei die Stirnflächen in Umfangsrichtung über wenigstens den überwiegenden Teil ihrer Umfangserstreckung aufeinander zu laufen, so dass sich die Finger in den kreiszylindrischen Schnitten jeweils in Umfangsrichtung verjüngen.In circular-cylindrical sections concentric to the axis of rotation, the fingers can each have a front side pointing in the direction of rotation, a back side pointing counter to the direction of rotation, a left-hand end face and a right-hand end face, with the end faces running towards one another in the circumferential direction over at least the majority of their circumferential extension, so that the fingers in the circular-cylindrical sections each taper in the circumferential direction.
Darüber hinaus können die Finger in kreiszylindrischen, zur Drehachse konzentrischen Schnitten jeweils eine in Drehrichtung weisende Vorderseite, eine gegen die Drehrichtung weisende Rückseite, eine linke Stirnfläche und eine rechte Stirnfläche aufweisen, wobei die Stirnflächen in den kreiszylindrischen Schnitten pfeilförmig aufeinander zulaufen.In addition, the fingers in circular-cylindrical sections concentric to the axis of rotation can each have a front side pointing in the direction of rotation, a rear side pointing counter to the direction of rotation, a left-hand end face and a right-hand end face, the end faces in the circular-cylindrical sections converging in the shape of arrows.
Bei einer weiteren beispielhaften Ausführungsform sind die Finger in kreiszylindrischen, zur Drehachse konzentrischen Schnitten kreisförmig oder ellipsenförmig langgestreckt. Unabhängig davon können sich die Finger in kreiszylindrischen, zur Drehachse konzentrischen Schnitten jeweils über wenigstens den überwiegenden Teil ihrer Umfangserstreckung in Umfangsrichtung verjüngen.In a further exemplary embodiment, the fingers are elongated in a circular or elliptical shape in circular-cylindrical sections concentric to the axis of rotation. Irrespective of this, the fingers can each taper in circular-cylindrical sections concentric to the axis of rotation over at least the predominant part of their circumferential extent in the circumferential direction.
Die Finger des erfindungsgemäßen Siebsterns sind bei einer weiteren beispielhaften Ausführungsform in kreiszylindrischen, zur Drehachse konzentrischen Schnitten jeweils eine in Drehrichtung weisende Vorderseite, eine gegen die Drehrichtung weisende Rückseite, eine linke Stirnfläche und eine rechte Stirnfläche aufweisen und in den kreiszylindrischen Schnitten die Vorderseite in Drehrichtung und/oder die Rückseite gegen die Drehrichtung pfeilförmig ist oder sind. Dabei kann die Vorderseite und/oder die Rückseite eine linke Flachseite und eine rechte Flachseite aufweisen und die Flachseiten können pfeilförmig aufeinander zulaufen. Insbesondere sind die Flachseiten plan oder rund nach außen gewölbt.In a further exemplary embodiment, the fingers of the sieve star according to the invention each have a front side pointing in the direction of rotation, a rear side pointing against the direction of rotation, a left end face and a right end face in circular-cylindrical sections concentric to the axis of rotation, and in the circular-cylindrical sections the front side in the direction of rotation and /or the back is or are arrow-shaped against the direction of rotation. The front and/or the back can have a left flat side and a right flat side and the flat sides can converge in the shape of an arrow. In particular, the flat sides are flat or rounded outwards.
Bei einer weiteren beispielhaften Ausführungsform weisen die Finger jeweils eine in Drehrichtung weisende Vorderseite, eine gegen die Drehrichtung weisende Rückseite, eine äußere linke Stirnfläche und eine äußere rechte Stirnfläche auf, wobei die Vorderseite und/oder die Rückseite konvex ist oder sind. Dabei kann die Vorderseite in Drehrichtung und/oder die Rückseite gegen die Drehrichtung nach außen rund gewölbt sein.In another exemplary embodiment, the fingers each have a rotationally facing front surface, an anti-rotational rear surface, an outer left face, and an outer right surface, with the front and/or the rear surface being or being convex. The front side can be curved outwards in the direction of rotation and/or the back side against the direction of rotation.
Bei einer Weiterbildung kann die Nabe aus einem härteren Material als die Finger, beispielsweise einem metallenen Werkstoff oder einem härteren Kunststoff- oder Gummimaterial, bestehen.In a further development, the hub can consist of a harder material than the fingers, for example a metal material or a harder plastic or rubber material.
Bei einer weiteren beispielhaften Ausführungsform sind die Nabe und die Finger jeweils aus Kunststoffmaterial geformt, wobei das Kunststoffmaterial im Bereich der freien Enden der Finger mit einem Reibverschleiß mindernden Zuschlagstoff gefüllt ist.In a further exemplary embodiment, the hub and the fingers are each formed from a plastic material, the plastic material being filled with an additive which reduces fretting in the region of the free ends of the fingers.
Vorteilhafterweise bestehen die Finger aus einem elastomeren Kunststoffmaterial oder Gummimaterial, das optional mit Verstärkungsmaterial gefüllt ist.Advantageously, the fingers are made of an elastomeric plastics or rubber material optionally filled with reinforcing material.
Die Finger des erfindungsgemäßen Siebsterns weisen vorteilhafterweise axial jeweils in einem Fußbereich eine Breite BF und am freien Ende eine Breite BE auf, wobei BF/BE wenigstens 1.5 und höchstens 2.5, vorzugsweise 1.8 ± 0.2, ist.The fingers of the sieve star according to the invention advantageously have a width B F axially in a foot area and a width B E at the free end, with B F /B E being at least 1.5 and at most 2.5, preferably 1.8±0.2.
Der Siebstern kann axial eine größte Breite BN im Bereich der Nabe aufweisen und die Finger können axial eine größte Breite BF jeweils im Fußbereich aufweisen, wobei BN/BF wenigstens 1.5 und höchstens 2.5, vorzugsweise 1.8 ± 0.3, ist.The sieve star can have a maximum axial width B N in the area of the hub and the fingers can have a maximum axial width BF in the foot area, with B N /B F being at least 1.5 and at most 2.5, preferably 1.8±0.3.
Alternativ oder Zusätzlich kann der Siebstern axial eine größte Breite BN im Bereich der Nabe aufweisen und die Finger können axial jeweils am freien Ende eine Breite BE aufweisen, wobei BN/BE wenigstens 2 und höchstens 4, vorzugsweise 3.2 ± 0.4, ist.Alternatively or additionally, the sieve star can have a maximum axial width B N in the area of the hub and the fingers can each have a width B E at the free end, with B N /B E being at least 2 and at most 4, preferably 3.2±0.4 .
Bei einer beispielhaften Ausführungsform hat ein Flugkreis des Siebsterns oder ein radial außen an die freien Enden der Finger angelegter Hüllkreis einen Durchmesser von wenigstens 150 mm und höchstens 300 mm, vorzugsweise 190 ± 40 mm.In an exemplary embodiment, a flight circle of the sieve star or an enveloping circle placed radially on the outside at the free ends of the fingers has a diameter of at least 150 mm and at most 300 mm, preferably 190±40 mm.
Ein Fingerfußkreis des Siebsterns oder ein Außenumfang der Nabe kann einen Durchmesser von wenigstens 50 mm und höchstens 200 mm, vorzugsweise 100 ± 30 mm, haben.A finger foot circle of the screen star or an outer circumference of the hub can have a diameter of at least 50 mm and at most 200 mm, preferably 100±30 mm.
Bei einer beispielhaften Ausführungsform weist die Nabe an den beiden Stirnseiten des Siebsterns um die Drehachse des Siebsterns umlaufend jeweils einen Bund auf, der axial um wenigstens 1 mm und höchstens 12 mm, vorzugsweise 7 ± 3 mm, über die Finger vorsteht.In an exemplary embodiment, the hub on both end faces of the sieve star has a collar around the axis of rotation of the sieve star, which protrudes axially by at least 1 mm and at most 12 mm, preferably 7±3 mm, over the fingers.
Die Nabe des Siebsterns kann einen zentralen axialen Durchgang mit einem nicht kreisrunden Querschnitt, vorzugsweise mit wenigstens einer flachen Seite, für eine drehunbewegliche Montage auf der Welle aufweisen.The hub of the screen star may have a central axial passage with a non-circular cross-section, preferably with at least one flat side, for non-rotating mounting on the shaft.
Nachstehend werden weiterbildende Ausführungsformen der Siebvorrichtung nach Anspruch 10 beschrieben.Further developing embodiments of the screening device according to claim 10 are described below.
Bei einer ersten beispielhaften Ausführungsform der Siebvorrichtung beträgt eine radiale Spaltweite über eine axiale Länge des jeweiligen frontalen Siebspalts überall wenigstens 2 mm und höchstens 12 mm, vorzugsweise 6 ± 2 mm. Eine seitliche Spaltweite kann längs des jeweiligen seitlichen Siebspalts überall wenigstens 1 mm und höchstens 10 mm, vorzugsweise 4 ± 2 mm, betragen.In a first exemplary embodiment of the screening device, a radial gap width over an axial length of the respective frontal screening gap is at least 2 mm and at most 12 mm, preferably 6±2 mm. A lateral gap width can be along the respective lateral screen gap everywhere at least 1 mm and at most 10 mm, preferably 4 ± 2 mm.
Bei einem weiteren Ausführungsbeispiel umfasst die Siebvorrichtung eine Antriebseinrichtung für den Drehantrieb der Wellen, wobei die Antriebseinrichtung dazu eingerichtet ist, benachbarte Wellen mit gleicher Drehzahl anzutreiben.In a further exemplary embodiment, the screening device comprises a drive device for driving the shafts in rotation, with the drive device being set up to drive adjacent shafts at the same speed.
Unabhängig davon kann die Siebvorrichtung eine Antriebseinrichtung für den Drehantrieb der Wellen umfassen, wobei die Antriebseinrichtung dazu eingerichtet ist, die Drehzahl wenigstens einer der Wellen im Betrieb der Vorrichtung relativ zur Drehzahl einer benachbarten Welle zu variieren.Irrespective of this, the screening device can comprise a drive device for rotating the shafts, the drive device being set up to vary the speed of at least one of the shafts during operation of the device relative to the speed of an adjacent shaft.
Nachfolgend werden Ausführungsbeispiele der Erfindung anhand von Figuren erläutert. An den Figuren offenbar werdende Merkmale bilden jeweils einzeln und auch in jeder, in sich nicht widersprüchlichen Merkmalskombinationen die Gegenstände der Ansprüche und auch die vorstehend beschriebenen Ausgestaltungen vorteilhaft weiter. Es zeigen:
Figur 1- einen beispielhaften und im Stand der Technik bekannten Siebstern eines ersten Ausführungsbeispiels in einer axialen Sicht auf eine Stirnseite, zur Erleichterung des Verständnisses der Erfindung,
Figur 2- den Siebstern in einer perspektivischen Sicht,
Figur 3- den Siebstern im Schnitt
A-A der Figur 1 , Figur 4- den Schnitt B-B durch einen Finger des Siebsterns der
Figur 1 , - Figur 5
- den Siebstern in einer radialen Sicht auf den äußeren Umfang,
Figur 6- eine Siebvorrichtung mit aus dem Stand der Technik bekannten Siebsternen in einem Schnitt,
Figur 7- die
Siebvorrichtung der Figur 6 in einer axialen Sicht, Figur 8- eine Draufsicht auf eine Siebfläche einer Siebvorrichtung mit weiteren aus dem Stand der Technik bekannten Siebsternen,
Figur 9- eine Draufsicht auf eine Siebfläche einer Siebvorrichtung mit weiteren aus dem Stand der Technik bekannten Siebsternen,
Figur 10- Formen des Querschnitts B-B der Finger von Siebsternen,
Figur 11- einen erfindungsgemäßen Siebstern in einer axialen Sicht auf eine Stirnseite,
Figur 12- den
Siebstern der Figur 11 im Schnitt B-B, Figur 13- den Schnitt A-A durch einen Finger des Siebsterns der
Figur 11 , Figur 14- den Siebstern der
Figur 11 in einer perspektivischen Sicht, Figur 15- alternative Formen des Querschnitts B-B von in Umfangsrichtung verjüngten Fingern von Siebsternen,
- Figur 16
- zusammenwirkende Siebsterne des ersten Ausführungsbeispiels mit linienförmiger Engstelle im seitlichen Siebspalt,
- Figur 17
- zusammenwirkende Siebsterne des vierten Ausführungsbeispiels mit punktförmiger Engstelle im seitlichen Siebspalt, und
- Figur 18
- die Siebsterne der
Figur 17 in veränderter Drehposition.
- figure 1
- an exemplary and in the prior art known sieve star of a first embodiment in an axial view of a front side, to facilitate understanding of the invention,
- figure 2
- the sieve star in a perspective view,
- figure 3
- the sieve star in the average AA of the
figure 1 , - figure 4
- the cut BB through a finger of the sieve star the
figure 1 , - figure 5
- the screen star in a radial view of the outer circumference,
- figure 6
- a screening device with screening stars known from the prior art in a section,
- figure 7
- the screening device
figure 6 in an axial view, - figure 8
- a plan view of a screen surface of a screening device with other screening stars known from the prior art,
- figure 9
- a plan view of a screen surface of a screening device with other screening stars known from the prior art,
- figure 10
- Shapes of cross-section BB of fingers of sieve stars,
- figure 11
- a screen star according to the invention in an axial view of a front side,
- figure 12
- the sieve star
figure 11 on average BB, - figure 13
- the cut AA through a finger of the sieve star the
figure 11 , - figure 14
- the sieve star
figure 11 in a perspective view, - figure 15
- alternative shapes of the cross-section BB of circumferentially tapered fingers of sieve stars,
- figure 16
- cooperating screen stars of the first embodiment with a linear constriction in the lateral screen gap,
- figure 17
- interacting screen stars of the fourth embodiment with a punctiform constriction in the lateral screen gap, and
- figure 18
- the sieve stars of
figure 17 in a different rotational position.
Die
Von dem Begriff "Umfangsrichtung" werden die Dreh- und die Drehgegenrichtung gleichermaßen erfasst, während bei Verwendung des Begriffs "Drehrichtung" zwischen diesen beiden Umfangsrichtungen unterschieden werden soll.The term “circumferential direction” covers the direction of rotation and the opposite direction in equal measure, while when using the term “direction of rotation” a distinction is to be made between these two circumferential directions.
Die Finger 5a sind elastisch biegbar und dadurch nachgiebig. Sie bestehen aus einem Kunststoffmaterial. Die Nabe 2 kann aus dem gleichen oder einem anderen, dann zweckmäßigerweise härteren Kunststoffmaterial geformt sein. Die Nabe 2 weist im zentralen Bereich einen Durchgang 3 für die Anordnung auf der Welle auf. Der Durchgang 3 ist als Mehrflach geformt, um den Siebstern 1 formschlüssig mit der Welle drehunbeweglich zu verbinden. Die Nabe 2 kann für eine drehunbewegliche Anordnung auf einer drehantreibbaren Welle in einem zentralen Bereich einen Einsatz aus einem metallenen Werkstoff aufweisen, bevorzugter ist der Kunststoff im Bereich der Nabe 2 jedoch ausreichend fest und hart, so dass auf einen derartigen Einsatz verzichtet werden kann.The
Wie in
Einer der Finger 5a dient als Reinigungsfinger. An der Vorderseite dieses Reinigungsfingers 5a ist ein Reinigungselement 9 aus einem metallenen Werkstoff abgestützt. In einer Siebvorrichtung mit mehreren nebeneinander angeordneten Wellen, auf denen jeweils axial nebeneinander mehrere der Siebsterne 1 angeordnet sind und kämmend ineinander greifen, wirkt das Reinigungselement 9 des jeweiligen Siebsternsl als Schaber, der anhaftendes Material von den axial benachbarten Siebsternen 1 und der einen oder den zwei benachbarten Wellen schabt und dadurch dadurch dazu beiträgt, dass die Siebspalte nicht verstopfen. Der Reinigungsfinger 5a ist zur Erhöhung der Steifigkeit gegen Biegung nicht sichelförmig, sondern zumindest im Wesentlichen gerade in die Radialrichtung R und gegen die Drehrichtung T erstreckt und weist in Umfangsrichtung T gemessen eine größere Dicke als die anderen Finger 5a auf. Vorteilhafte Konfigurationen für die Kombination aus Reinigungsfinger 5a und Reinigungselement 9 werden beispielsweis in der
Bei Drehung um die Drehachse D laufen die freien Enden 7 aller Finger 5a und auch das freie Ende des Reinigungselements 9 auf einem Hüllkreis mit dem Durchmesser DH um. Die Nabe 2 weist im Bereich des Bunds 4 einen Außenumfang mit Durchmesser DN auf, der im Sinne der Erfindung als Durchmesser des Fußkreises der Finger 5a angesehen wird. Der Durchmesser DH ist aus dem Bereich von 150 mm bis 250 mm, vorzugsweise 150 mm bis 230 mm, gewählt. Der Durchmesser DN ist aus dem Bereich von 50 mm bis 200 mm, vorzugsweise 70 mm bis 130 mm, gewählt. Die radiale Erstreckung der Finger 5a ist aus dem Bereich von 50 mm bis 180 mm, vorzugsweise 80 mm bis 120 mm, gewählt. Dies sind nur Beispiele bevorzugter Größenbereiche. Die Erfindung ist vorteilhaft auch für andere Durchmesserbereiche.When rotating about the axis of rotation D, the free ends 7 of all
Die Finger 5a weisen jeweils bezogen auf die Drehrichtung eine Vorderseite oder vordere Oberfläche 10, eine Rückseite oder rückwärtige Oberfläche 11, eine linke Stirnfläche 12 und eine rechte Stirnfläche 13, und verbindende Übergänge 14 an der Vorderseite 10 und verbindende Übergänge 15 an der Rückseite 11 auf. Die Übergänge 14 und 15 sind weich gerundet, indem sie mit jeweils einem Krümmungsradius von 1,5 mm oder mehr, vorzugsweise von 2 mm oder mehr, die jeweilige Stirnfläche 12 und 13 mit der vorderen Oberfläche 10 und der hinteren Oberfläche 11 verbinden. Durch die Vermeidung scharfer Kanten am jeweiligen Übergang 14 und 15 wird dem Anhaften bindiger Siebgutbestandteile entgegengewirkt.The
Die Finger 5a und auch der Reinigungsfinger 5a verjüngen sich jeweils vom Fußbereich 6 in Richtung auf das freie Ende 7 fortschreitend, d.h. sie verjüngen sich in Längsrichtung L des jeweiligen Fingers 5a erstreckten Schnitten C-C. Hieraus ergeben sich günstige Verhältnisse hinsichtlich der gewünschten elastischen Biegbarkeit längs der Finger 5a einerseits bei ausreichender Stabilität im jeweiligen Fußbereich 6 andererseits. Die Verjüngung längs der Finger 5a geht mit einer Verjüngung auch in radialer Richtung R und somit in die Drehachse D beinhaltenden Längsschnitten des Siebsterns 1 einher. In
In
In den in Längsrichtung L des jeweiligen Fingers 5a erstreckten Schnitten C-C verläuft die Verjüngung über eine größere Länge, ansonsten aber analog zur Verjüngung im Schnitt A-A, so dass die Stirnflächen 12 und 13 in den Schnitten C-C mit einem Neigungswinkel, der geringfügig kleiner als der Winkel α ist, aufeinander zu laufen. Die Stirnflächen 12 und 13 laufen jeweils längs der Finger 5a vom Fußbereich 6 bis zum freien Ende 7 monoton und stetig differenzierbar aufeinander zu. Die Finger 5a verjüngen sich in Fingerlängsrichtung L jeweils in jedem Längenabschnitt.In the sections CC extending in the longitudinal direction L of the
Der Reinigungsfinger 5a entspricht in Bezug auf die Verjüngung den anderen Fingern 5a. Im Ausführungsbeispiel verjüngt sich der Reinigungsfinger 5a somit in Längsrichtung des Reinigungsfingers 5a und nach radial außen jeweils symmetrisch zur zentralen Querschnittsebene Q.The
Die Finger 5a weisen jeweils längs der Nabe 2 ihre größte Breite, BN, am Fußkreis eine demgegenüber geringere Breite, BF, und an den freien Enden 7 die kleinste Breite, BE, auf. Vorteilhaft sind folgende Verhältnisbereiche:
- 1.5 ≤ BF/BE ≤ 2.5, vorzugsweise 1.6 ≤ BF/BE ≤ 2
- 1.5 ≤ BN/BF ≤ 2.5, vorzugsweise 1.5 ≤ BN/BF ≤ 2.1
- 2 ≤ BN/BE ≤ 4, vorzugsweise 2.8 ≤ BN/BE ≤ 3.6
- 1.5 ≤ BF / BE ≤ 2.5, preferably 1.6 ≤ BF / BE ≤ 2
- 1.5 ≤ B N /B F ≤ 2.5, preferably 1.5 ≤ B N /B F ≤ 2.1
- 2 ≤ B N / BE ≤ 4, preferably 2.8 ≤ B N / BE ≤ 3.6
Die Nabenbreite BN ist aus dem Bereich von 25 mm bis 40 mm, vorzugsweise 30 mm bis 40 mm, gewählt. Die Fußkreisbreite BF ist aus dem Bereich von 12 mm bis 25 mm, vorzugsweise 15 mm bis 22 mm, gewählt. Die Endenbreite BE ist aus dem Bereich von 5 mm bis 20 mm, vorzugsweise 7 mm bis 15 mm, gewählt. Dies sind nur Beispiele bevorzugter Größenbereiche. Die Erfindung ist vorteilhaft auch für andere Breitenbereiche.The hub width B N is selected from the range of 25 mm to 40 mm, preferably 30 mm to 40 mm. The root circle width B F is selected from the range of 12 mm to 25 mm, preferably 15 mm to 22 mm. The end width B E is selected from the range of 5 mm to 20 mm, preferably 7 mm to 15 mm. These are just examples of preferred size ranges. The invention is also advantageous for other width ranges.
Die
Die Siebvorrichtung weist mehrere drehantreibbare Wellen 20 auf, die nebeneinander angeordnet und längs denen jeweils mehrere Siebsterne 1 nebeneinander angeordnet sind. Die Siebsterne 1 sind verdrehgesichert auf den Wellen 20 montiert. Die Siebsterne 1 benachbarter Wellen 20 greifen mit ihren Fingern 5a kammartig ineinander, so dass die Siebsterne 1 der einen Welle 20 mit den Siebsternen 1 der benachbarten Welle 20 in Wellenlängsrichtung alternierend aufeinander folgend seitliche Siebspalte 21 und frontale Siebspalte 22 bilden, die in der Draufsicht gemeinsam einen in axialer Richtung mäanderförmig verlaufenden, zusammenhängenden Siebspalt 21, 22 ergeben. Die einander zugewandten Stirnflächen ineinandergreifender Siebsterne 1 begrenzen die seitlichen Siebspalte 21. Die freien Enden 7 der Siebsterne 1 begrenzen mit den radial zugewandten, äußeren Umfangsflächen der Bunde 4 der Siebsterne 1 der jeweils benachbarten Welle 20 die frontalen Siebspalte 22.The screening device has a plurality of rotationally
Die seitlichen Siebspalte 21 weisen der kegelförmigen Verjüngung der Siebsterne 1 entsprechend jeweils eine im Schnitt E-E streifenförmige engste Sieblücke mit einer Spaltweite Ws auf. In Umfangsrichtung der Siebsterne 1 ist die engste Sieblücke linienförmig. Die frontalen Siebspalte 22 weisen jeweils zwischen dem freien Ende 7 und der äußeren Umfangsfläche der beiden Bunde 4 eine engste Sieblücke mit einer radialen Spaltweite WR auf. Die Spaltweiten WR und Ws bestimmen maßgeblich die Feinheit des von den Siebsternen 1 gebildeten Sternsiebs. Durch die Verjüngung in Längsrichtung der Finger 5a wird die axiale Länge der frontalen Siebspalte 22 im Vergleich zu einfach scheibenförmigen Siebsternen 1 gleichen Materials und gleicher Stabilität verringert. Dies trägt insbesondere dann zu einer erhöhten Feinheit des Sternsiebs bei, wenn die radiale Spaltweite WR größer als die seitliche Spaltweite Ws ist. Da die Finger 5a in Richtung auf ihre freien Enden 7 zweckmäßigerweise nicht spitz auslaufen, sondern am freien Ende 7 abgeflacht sind, könnten bei entsprechend großer radialer Spaltweite WR frontale Siebspalte 22 entstehen, durch die vergleichsweise große, kompakte Partikel durch das Sternsieb nach unten fallen würden. Die Verjüngung in Längsrichtung der Finger 5a wirkt dem entgegen.The
In einer Abwandlung kann die Siebvorrichtung alternierend nebeneinander erste Wellen 20 mit Siebsternen 1 des ersten Ausführungsbeispiels und zweite Wellen 20 mit Siebsternen 1 des zweiten Ausführungsbeispiels aufweisen. Auch in derartigen Abwandlungen, in denen konisch verjüngte Siebsterne 1 mit konvex verjüngten Siebsternen 1 kämmen, ergeben sich für die seitlichen Siebspalte 21 punktförmige Engstellen.In a modification, the screening device can alternately have
Durch das Zusammenwirken von Siebsternen 1 mit konvexen Fingern 5b mit Siebsternen 1 mit konkaven Fingern 5c werden seitliche Siebspalte 21 erhalten, die dem konvex-konkaven Verlauf der Stirnflächen 12 und 13 entsprechend gekrümmt sind. Hierdurch wird die Feinheit des Sternsiebs erhöht, da lange dünne Siebgutpartikel die gekrümmten Siebspalte 21 (
Der Finger 5d hat im Schnitt B-B die Form eines Rechtecks. Er unterscheidet sich vom Finger 5a des ersten Ausführungsbeispiels nur dadurch, dass auch die vordere Oberfläche 10 und die rückwärtige Oberfläche 11 im jeweiligen Schnitt B-B gerade sind.The
Der Finger 5e entspricht im Bereich der vorderen Oberfläche 10 und den beiden Stirnflächen 12 und 13 dem Finger 5a des ersten Ausführungsbeispiels, ist jedoch im Unterschied zu diesem an der rückwärtigen Oberfläche 11 pfeilförmig konvex.The
Der Finger 5f weist im Schnitt B-B zwei parallele Stirnflächen 12 und 13, eine pfeilförmig konvexe vordere Oberfläche 10 und eine pfeilförmig konvexe rückwärtige Oberfläche 11 auf.The
Der Finger 5g weist über etwa die Hälfte seiner Umfangserstreckung parallele Stirnflächen 12 und 13, eine hierzu orthogonale, im Schnitt B-B gerade rückwärtige Oberfläche 11 und eine im Schnitt B-B halbovale, beispielsweise kreisförmige oder elliptische, vordere Oberfläche 10 auf.The finger 5g has parallel end faces 12 and 13 over about half of its circumferential extent, a
In den
Die Finger 5h verjüngen sich vom Fußbereich 6 aus in Richtung auf das freie Ende 7, d.h. in Fingerlängsrichtung L, wie die Finger 5a des ersten Ausführungsbeispiels. Abweichend von den Fingern 5a verjüngen sich die Finger 5h aber auch über zumindest den überwiegenden Teil ihrer in Umfangsrichtung T gemessenen Umfangserstreckung.The
In Längsschnitten, wie beispielsweise in dem in
Die Überlagerung der Verjüngung in Fingerlängsrichtung L und der Verjüngung in Umfangsrichtung T ist auch in der Perspektive der
Der Siebstern 1 des vierten Ausführungsbeispiels kann in alternativen Ausführungen in Bezug auf die Verjüngung in Fingerlängsrichtung L auch dem zweiten Ausführungsbeispiel entsprechend konvex oder dem dritten Ausführungsbeispiel entsprechend konkav verjüngt sein.In alternative embodiments, the
Der Finger 5i ist vom Finger 5h des vierten Ausführungsbeispiels abgeleitet und unterscheidet sich von diesem dadurch, dass die vordere Oberfläche 10 und die rückwärtige Oberfläche 11 über die gesamte Breite des Fingers 5d jeweils konvex rund gewölbt sind.The finger 5i is derived from the
Der Finger 5j ist im Schnitt B-B dreieckförmig, wobei die "Spitze" des Dreiecks in Drehrichtung T nachläuft.The finger 5j is triangular in section B-B, with the "point" of the triangle trailing in the direction of rotation T.
Der Finger 5k weist im Schnitt B-B eine pfeilförmige vordere Oberfläche 10, eine axial erstreckte rückwärtige Oberfläche 11 und zwei gerade, gegen die Drehrichtung T spitzwinklig aufeinander zulaufende Stirnflächen 12 und 13 auf.The
Der Finger 51 ist im Schnitt B-B rautenförmig mit zwei Stirnflächen 12 und 13, die aus einem in Umfangsrichtung mittleren, breiten Bereich in Drehrichtung T auf die nur als "Spitze" ausgebildete vordere Oberfläche 10 zulaufen und auch gegen die Drehrichtung T auf die ebenfalls nur als "Spitze" ausgebildete rückwärtige Oberfläche 11 zulaufen. Der Finger 51 ist im Ergebnis in beide Umfangsrichtungen, d. h. in Drehrichtung T und gegen die Drehrichtung T, pfeilförmig verjüngt.The
Der Finger 5m ist im Schnitt B-B oval, beispielsweise elliptisch, wobei die Erstreckung in Umfangsrichtung T größer als die axiale Erstreckung, d. h. größer als die Breite, ist. Die ovale Form, beispielsweise elliptische Form, ist im Hinblick auf den im Betrieb auftretenden Verschleiß und auch wegen der sich im seitlichen Siebspalt punktförmig bildenden Engstelle zur Reduzierung des Anhaftens bindiger Siebgutbestandteile günstig.The
In den Darstellungen der Finger 5d bis 5g und 5i bis 5m sind die Übergänge zwischen den Flächen 10 bis 13 jeweils als Kanten dargestellt. In bevorzugten Ausführungen sind aber auch diese Finger an den betreffenden Übergängen weich gerundet mit einem Krümmungsradius von jeweils wenigstens 1.5 mm oder, bevorzugt, wenigstens 2 mm.In the representations of the
Die
- 11
- Siebsternsieve star
- 22
- Nabehub
- 33
- Durchgangpassage
- 44
- BundFederation
- 5a-m5a-m
- Fingerfinger
- 66
- Fingerfußbereichfinger foot area
- 77
- freies Endefree end
- 88th
- --
- 99
- Reinigungselementcleaning element
- 1010
- Vorderseite, vordere OberflächeFront, front surface
- 1111
- Rückseite, rückwärtige Oberflächeback, back surface
- 1212
- Stirnseite, linke StirnflächeFront face, left front face
- 1313
- Stirnseite, rechte Stirnflächefront face, right front face
- 1414
- vorderer Übergangfront transition
- 1515
- rückwärtiger Übergangbackward transition
- 1616
- --
- 1717
- --
- 1818
- --
- 1919
- --
- 2020
- WelleWave
- 2121
- seitlicher Siebspaltlateral sieve gap
- 2222
- frontaler Siebspaltfrontal screen gap
- BEBE
- Breite des freien Endeswidth of the free end
- BFbf
- Breite im FingerfußbereichWidth in the finger foot area
- BNB.N
- Breite der Nabewidth of the hub
- DD
- Drehachseaxis of rotation
- DNDN
- Durchmesser der Nabediameter of the hub
- DHIE
- Durchmesser des Hüllkreisesdiameter of the enveloping circle
- ELel
- Engstellebottleneck
- Epep
- Engstellebottleneck
- RR
- radiale Richtungradial direction
- TT
- Umfangsrichtung, DrehrichtungCircumferential direction, direction of rotation
- XX
- axiale Richtungaxial direction
- WsWs
- seitliche Spaltweitelateral gap width
- WRWR
- radiale Spaltweiteradial gap width
Claims (15)
- A screening star for a screening device, the screening star comprising:1.1 a hub (2) for non-rotatably arranging the screening star (1) on a rotatable shaft (20); and1.2 elastically flexible fingers (5a-m) which protrude radially outwards from the hub (2) in a distribution in the circumferential direction about a rotational axis (D) of the screening star (1) and which each extend in the circumferential direction (T) from a base region (6) up to a free end (7) which is a trailing end in the rotational direction,1.3 wherein the fingers (5a-m) each comprise a left-hand end-facing area (12) and a right-hand end-facing area (13), and the end-facing areas (12, 13) each exhibit an inclination (α) with respect to a central cross-sectional plane (Q) of the screening star (1), such that the end-facing areas (12, 13) converge in the direction (L) of the free end (7) of the respective finger (5a-m), and the fingers (5a-m) taper in the direction (L) of the free end (7) of the respective finger (5a-m) on both end-facing sides (12, 13) of the screening star (1),wherein that
1.4 the fingers (5a-m) taper, in circular-cylindrical sections (B-B) which are concentric with respect to the rotational axis (D), in a circumferential direction (T) on at least one end-facing area (12, 13). - The screening star according to claim 1, wherein the fingers (5a-m) each taper on both end-facing sides (12, 13) over at least most of their length as measured from the base region (6) up to the free end (7).
- The screening star according to any one of the preceding claims, wherein the fingers (5a-m) taper progressively outwards on both end-facing sides (12, 13) of the screening star (1) in the direction (L) of the free end (7) of the respective finger (5a-m) symmetrically in relation to a cross-sectional plane (Q) of the screening star (1).
- The screening star according to any one of the preceding claims, wherein the fingers (5a; 5h) conically taper progressively outwards on both end-facing sides (12, 13) of the screening star (1) in the direction (L) of the free end (7) of the respective finger (5a; 5h) at a constant angle of inclination (α), or the fingers (5b) taper progressively outwards on both end-facing sides (12, 13) of the screening star (1) in the direction (L) of the free end (7) of the respective finger (5b) at a varying angle of inclination (α), such that the two end-facing sides (12, 13) are curved convexly outwards or concavely inwards in a round shape.
- The screening star according to any one of the preceding claims, wherein the fingers (5a-m) taper, in circular-cylindrical sections (B-B) which are concentric with respect to the rotational axis (D), in a circumferential direction (T) on both end-facing areas (12, 13).
- The screening star according to the preceding claim, wherein the fingers (5a-m) taper in the circumferential direction (T), in the circular-cylindrical sections (B-B), symmetrically with respect to a cross-sectional plane (Q) of the screening star (1).
- The screening star according to any one of the preceding claims, wherein the fingers (5h; 5i) each at least substantially form, in the circular-cylindrical sections (B-B), an isosceles trapezium comprising a long base which is a leading side in the rotational direction (T) and a short base which is a trailing side in the rotational direction (T).
- The screening star according to any one of claims 1 to 6, wherein the fingers (5m) are oval in circular-cylindrical sections (B-B) which are concentric with respect to the rotational axis (D).
- The screening star according to any one of the preceding claims, wherein the fingers (5a; 5e; 5g; 5i; 5m) each comprise, in circular-cylindrical sections (B-B) which are concentric with respect to the rotational axis (D), a front side (10) pointing in the rotational direction (T), a rear side (11) pointing counter to the rotational direction (T), a left-hand end-facing area (12) and a right-hand end-facing area (13), and wherein in circular-cylindrical sections (B-B) which are concentric with respect to the rotational axis (D), the front side (10) is curved outwards in a round shape in the rotational direction (T) at least over most of the axial width of the respective finger (5a; 5e; 5g; 5i; 5m) and/or the rear side (11) is curved outwards in a round shape counter to the rotational direction (T) at least over most of the axial width of the respective finger (5a; 5e; 5g; 5i; 5m).
- The screening star according to any one of the preceding claims, wherein the hub (2) and the fingers (5a-m) which are tapered on both sides are moulded together in one piece from plastic.
- The screening star according to any one of the preceding claims, wherein the hub (2) and fingers (5a-m) are each moulded from a plastic material, and the plastic material in a central region of the hub (2) has a higher Shore hardness than the plastic material in the base region (6) of the fingers (5a-m) and/or the plastic material in the region of the free ends (7) of the fingers (5a-m) has a higher Shore hardness than the plastic material in the base region (6) of the fingers (5a-m).
- A screening device, comprising:12.1 multiple shafts (20) arranged next to each other such that they can each rotate about a rotational axis (D); and12.2 for each shaft (20), multiple screening stars (1) arranged axially next to each other and non-rotatably connected to the respective shaft (20), each according to any one of the preceding claims,12.3 wherein the screening stars (1) of adjacent shafts (20) interlock and mesh, such that the end-facing areas (12, 13) of axially adjacent screening stars (1) delineate lateral screening gaps (21) and the free ends (7) of the screening stars (1) delineate frontal screening gaps (22).
- The screening device according to the preceding claim, wherein the lateral screening gaps (21) each exhibit a lateral gap width (Ws) orthogonally with respect to the mutually facing end-facing areas (12, 13) of axially adjacent screening stars (1), and the frontal screening gaps (22) each exhibit a radial width gap width (WR), and the lateral gap width (Ws) is smaller than the radial gap width (WR).
- The screening device according to any one of the immediately preceding two claims, wherein the mutually meshing screening stars (1) comprising mutually facing end-facing areas (12, 13) form linear constrictions (EL) or punctiform constrictions (EP) in accordance with their tapering, and the lateral gap width (Ws) is measured axially across the constriction (EL; EP).
- The screening device according to any one of the immediately preceding three claims, comprising a drive device for rotary-driving the shafts (20), wherein the drive device is designed to drive adjacent shafts (20) at different rotational speeds.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102018122601.2A DE102018122601A1 (en) | 2018-09-14 | 2018-09-14 | Sieve star for a sieve device |
Publications (2)
Publication Number | Publication Date |
---|---|
EP3628411A1 EP3628411A1 (en) | 2020-04-01 |
EP3628411B1 true EP3628411B1 (en) | 2022-11-02 |
Family
ID=67956589
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19197319.7A Active EP3628411B1 (en) | 2018-09-14 | 2019-09-13 | Screen star for a screening device |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP3628411B1 (en) |
DE (1) | DE102018122601A1 (en) |
PL (1) | PL3628411T3 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE202022105600U1 (en) | 2022-10-04 | 2022-11-02 | Günther Holding GmbH & Co. KG | Sieving device for sieving material to be sieved and sieve star for a sieving device |
DE202022105596U1 (en) | 2022-10-04 | 2022-10-17 | Günther Holding GmbH & Co. KG | Sieve star with cleaning element |
DE202022105599U1 (en) | 2022-10-04 | 2022-11-02 | Günther Holding GmbH & Co. KG | Sieving device for sieving material to be sieved and sieve star for a sieving device |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE534888C (en) * | 1928-12-06 | 1931-10-03 | A W Mackensen Maschinenfabrik | Roller grate |
DE4415815A1 (en) * | 1994-05-05 | 1995-11-09 | Gerhard Dipl Ing Mock | Screening device for sorting loose material |
GB9607826D0 (en) * | 1996-04-16 | 1996-06-19 | Pearson Richard Ltd | Agricultural separating device and agricultural separator |
US5975441A (en) * | 1997-12-29 | 1999-11-02 | Burkholder; Melvin M. | Apparatus for separating rocks from soil |
EP1088599B1 (en) * | 1999-10-01 | 2002-05-02 | Bernd Günther | Rotary screen element and method for cleaning rotary sceen elements |
DE102008054239A1 (en) * | 2008-10-31 | 2010-05-20 | Grimme Landmaschinenfabrik Gmbh & Co. Kg | Starwheel for starwheel rollers of conveying or separating devices |
DE202012005012U1 (en) * | 2012-05-21 | 2012-06-11 | Komptech Umwelttechnik Deutschland Gmbh | screening star |
-
2018
- 2018-09-14 DE DE102018122601.2A patent/DE102018122601A1/en active Pending
-
2019
- 2019-09-13 EP EP19197319.7A patent/EP3628411B1/en active Active
- 2019-09-13 PL PL19197319.7T patent/PL3628411T3/en unknown
Also Published As
Publication number | Publication date |
---|---|
PL3628411T3 (en) | 2023-02-20 |
DE102018122601A1 (en) | 2020-03-19 |
EP3628411A1 (en) | 2020-04-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP3628411B1 (en) | Screen star for a screening device | |
EP2143531B1 (en) | System with two different drive shafts and with a tool with an attachment opening for form-fit connection with the drive shafts | |
EP0879077B1 (en) | Device for filtering plasticised thermoplastics and filter unit therefor | |
EP2361159B1 (en) | Star screen, in particular for a star screen machine | |
EP3416473B1 (en) | Gathering device for crops | |
EP1088599B1 (en) | Rotary screen element and method for cleaning rotary sceen elements | |
EP2188064B1 (en) | Eccentric screen element for disk screens | |
EP3043962A1 (en) | Cutting tool | |
EP3669637B1 (en) | Agricultural harvester with conveyor drum | |
EP0303755B1 (en) | Apparatus for granulating chicken excrements or similar materials | |
DE10027909C2 (en) | Rotary screen element and method for cleaning rotary screen elements | |
EP3750390B1 (en) | Conveyor for a liquid manure distributor | |
EP2014834B1 (en) | Spinnerdisc for Winterservice-Spreading-Apparatus | |
EP0578051B1 (en) | Toothed packer roller | |
EP2772128A1 (en) | Flail knife and cutter block for the same | |
DE1156723B (en) | Screen grate | |
EP3940146A1 (en) | Spreading device for spreading vehicle | |
DE19952005B4 (en) | Star or disc sieve arrangement, comprising a plurality of sieve disc shafts | |
EP3195718B1 (en) | Cutting blade for a tool head of a free cutter | |
DE202008014705U1 (en) | Device for preparing the soil for sowing and for spreading seed | |
CH623453A5 (en) | ||
WO2013079209A1 (en) | Sifting star, in particular for a sifting star machine | |
DE2506952C2 (en) | Forage mower | |
DE202006002348U1 (en) | Soil processing device used as a cutting harrow comprises cutting units each having a cutter on its peripheral side and arranged on a hub section in the direction of the rotary axis | |
DE2049124A1 (en) | Machine for shredding bulky goods |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE |
|
17P | Request for examination filed |
Effective date: 20200831 |
|
RBV | Designated contracting states (corrected) |
Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: GRANT OF PATENT IS INTENDED |
|
INTG | Intention to grant announced |
Effective date: 20220422 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE PATENT HAS BEEN GRANTED |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D Free format text: NOT ENGLISH |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP Ref country code: AT Ref legal event code: REF Ref document number: 1528375 Country of ref document: AT Kind code of ref document: T Effective date: 20221115 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 502019006108 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D Free format text: LANGUAGE OF EP DOCUMENT: GERMAN |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: FP |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG9D |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20230302 Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20230202 Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: ES Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20230302 Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20230203 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 502019006108 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed |
Effective date: 20230803 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 20230920 Year of fee payment: 5 Ref country code: IE Payment date: 20230920 Year of fee payment: 5 Ref country code: GB Payment date: 20230920 Year of fee payment: 5 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: PL Payment date: 20230821 Year of fee payment: 5 Ref country code: FR Payment date: 20230928 Year of fee payment: 5 Ref country code: DE Payment date: 20230920 Year of fee payment: 5 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: CH Payment date: 20231001 Year of fee payment: 5 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20230913 |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20230930 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20230913 Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20221102 |