SE539243C2 - Feeder rotor for feeding granular or powdery material in an agricultural implement, feeder system with a feeder rotor, agricultural implement with a feeder system and method for feeding granular or powdery material - Google Patents

Abstract

17 SUMMARY This document shows a feed rotor (13, 13 ", 13") for feeding granular or powdered material into an agricultural implement. The latar rotor comprises a center portion (132) extending along an axial direction of the feed rotor. , and at least two rotor blades (131) extending radially outwardly from the center portion. The latar rotor has a sealing lip (133, 133 ", 133") which extends around, and axially outwardly, an axial end portion of the center portion, for providing of seal between the feed rotor (13, 13 ", 13") and a portion (125) which in the axial direction defines a feed space (123) in which the feed rotor is located. The document also shows a system for feeding granular or powdered material, an agricultural tool for feeding granular or powdered material and a method for feeding granular or powdered material. Publication image: Fig. 2

Description

IVIATARROTOR FOR IVIATNING granular ELLERPULVERFOFWIIGT IVIATERIAL IN LANTBRUKSREDSKAP.IVIATARSYSTEIVI WITH A MÅTÅRRÜTÜR, LANTERUlíSREDSKÅP MEDETT metering AND METHOD FOR IVIATNING AVGRANULÄRT OR PULVERFORNIIGT IVIATERIAL TECHNICAL FIELD This document relates to a rotor feeder for feeding granular material ellerpulverformigt, which finds application especially in the agricultural implement.

The document also relates to a system for feeding granular or powdered material comprising such a feed rotor and an agricultural implement comprising such a system.

The document also relates to a procedure for feeding granular or powdered material in an agricultural implement.

Background It is known from, for example, WO2013180619A1, that in an agricultural implement, granular or powdered material is fed from a material container via a feeder to a duct for receiving the material in an air stream, which feeds the material on to, for example, a plurality of saw beetles. The lathe comprises a feed housing, in which a feed rotor is rotatably arranged.

The air flow is typically provided by a fan or pump, which creates an overpressure in the duct that conducts the air flow.

To reduce energy consumption, it is desirable to ensure that the overpressure is maintained throughout the duct. One challenge is to insert the material into the channel without losing the overpressure.

One way to achieve this is by providing the material container with a tight-fitting lid, so that the overpressure is maintained all the way up in the material container. Another way to achieve this is to use an injector, whereby a vacuum suction to the channel is achieved according to the venturi principle.

Another way is to provide a feeder which acts as a single air lock and thus prevents the overpressure in the duct from leaking up to the material container, so that normal pressure can be allowed in the material container.

Normal pressure in the material container is advantageous in that it is difficult to create a large material container, with an equally large lid, which closes sufficiently tightly.

One problem is that both the environment in which agricultural implements are used and the material that is fed, often give rise to large amounts of dust and dirt, which makes it difficult to achieve good seals.

There is also a desire to reduce the energy consumption of agricultural implements. In addition, it is desirable to reduce the cost and weight of agricultural implements, for example by using electric motors, preferably electric motors that are not too large. Based on the premise that it is desirable to provide a feeder that functions as an airlock, there is a need for an improved feeder, and in particular a feeder that reduces air leakage in a reverse direction from feeder outlet to feeder inlet.

Summary A purpose is thus to achieve an improved feeder. A particular object is to provide a feeder which causes less pressure loss than known feeders.

The invention is defined by the independent claims. Embodiments appear from the dependent claims, from the following description and from the drawings.

According to a first aspect, a feed rotor for feeding is provided with granular or powdered material, comprising a center portion extending along an axial direction of the feed rotor, and at least two rotor blades extending radially outward from the center portion. The latar rotor has a sealing lip, which extends around, and axially outwardly, an axial end portion of the center portion, to provide a seal between the feed rotor and a portion which in the axial direction defines a feed space in which the feed rotor is located.

"Center portion" means a central portion of the feed rotor. This canvas is made in one piece with and from the same material as the feed rotor.

Alternatively, the center portion may be formed in another material other than the rotor, for example a stiffer material.

The sealing lip reduces leakage past the central portion of the feed rotor, from the material outlet to the material inlet. In addition, a sealing lip can be manufactured with good precision, so that its abutment force, and thus energy consumption, can be controlled.

In addition, the sealing lip reduces the risk of material or material residues entering the bearings around which the feed rotor is rotatable.

The sealing lip may have a proximal portion, at which the sealing lip connects to the feed rotor and a distal portion, which due to elasticity the cough sealing lip is movable relative to the feed rotor. The latar rotor may further comprise a gap located between the sealing lip and the rotor blades, the sealing lip being freely movable relative rotor blades.

The sealing lip can meet the respective rotor blade at a substantially right angle and wherein the gap has a substantially extension perpendicular to the bath rotor blade and the sealing lip.

The gap may be tapered in the drawing axially and / or radially towards the opposite center portion.

The sealing lip can be designed to provide prestressing in a radial direction.

Alternatively, or as a complement, the sealing lip may be designed to provide biasing in an axial direction. At least a part of the respective rotor blades may be made of a single-elastic material, preferably rubber-elastic material, such as rubber, thermoplastic elastomer or polyurethane.

For example, the rotor blades may be made entirely of elastic material. Alternatively, the radially and / or axially outer portions of the rotor blades may be made of elastic material. Such elastic portions can bend due to the friction with the wall against which they abut.

The radiator blades can, in the radial direction, have a substantially constant cross-sectional area over at least half, preferably at least 2/3 or at least 3A, of which their radial length.

Alternatively, or as a complement, the rotor blades, seen in the axial direction, may have a portion with in the direction of an axial end of the feed rotor the removal cross-sectional area.

Preferably, the portion extends over at least 1/10 or at least 1/5 of the axial length of the rotor blades. The decreasing cross-sectional area then reduces the abutment force while allowing the rotor blades to bend out.

According to a second aspect, a feed system is provided for feeding degranular or powdered material, comprising a feed housing, which defines a feed space, and a feed rotor as described above. The latar space has at least one axial limitation. The sealing lip abuts the axial boundary so that a sealed space is created, which extends around a geometric axis of rotation of the feed rotor.

The sealed space can be rotationally symmetrical. The lathar system may further comprise a projection extending axially into the feed space from the axial boundary, the sealing lip being radially biased towards a surface of the projection.

The surface may be substantially cylindrical or conical.

Alternatively, the sealing lip may abut against a substantially flat surface of the axial boundary, the sealing lip being axially biased against the flat surface. The latar system may further comprise at least one scraper part located between the sealing lip and the axial boundary, which is arranged so that through the rotation of the feed rotor in the feed housing carry dust and particles which have ended up between the seal and the axial boundary radially outwards.

The scraper portion may comprise an edge extending at an angle to the radius of the sealing lip, so that the rotation of the feed rotor causes dust and particles to migrate radially leaky and away from the area between the axial boundary and the sealing lip. In one embodiment, the rotor blades may be biased toward at least one of the axial restraints and a cylindrical sector-shaped restraint.

By prestressing the rotor blades, a tight abutment can be achieved, which reduces or prevents air leakage in the direction from the material outlet to the material inlet.

According to a third aspect, there is provided an agricultural implement for feeding degranular or powdered material, comprising a container for the material, an air flow generating device, and a channel connected to the air flow generating device. The agricultural implement comprises a feeding system according to what is described above, arranged for feeding the material from the container to the air duct.

According to a fourth aspect, a method is provided for feeding degranular or powdered material into an agricultural implement, comprising causing a feed rotor to rotate in a feed space, which is partly defined by axial restriction, and to seal a space between the axial restriction and by means of a sealing lip. an axial end of the feed rotor.

The method may further comprise biasing the sealing lip in the axial and / or radial direction towards the axial boundary.

The method may further comprise, by means of an intermediate sealing lip and the axial restriction located scraper part and the rotation of the feed rotor in the feed housing, bringing dust and particles which have ended up between the seal and the axial restriction radially outwards.

Brief Description of the Drawings Fig. 1 is a schematic view of a feed system 1 for feeding degranular or powdered material.

Figures 2a-2c show a feed rotor according to a first embodiment.

Figs. 3a-3d show a feed rotor according to a second embodiment.

Fig. 4 shows a feed rotor according to a third embodiment.

Fig. 5 shows a connection between a wing blade of a feed rotor according to the embodiments and an axial wall of the feed space.

Fig. 6 shows a connection between a wing blade of a feed rotor according to the embodiments and a cylindrical wall of the feed space.

Figures 7a-7c show different embodiments of arrangements for cleaning the seal between the feed rotor and the axial constraint.

Detailed description Fig. 1 shows a feeding system 1, which can be supported by an agricultural implement 0, and is used there to distribute granular or powdered material to land over which the agricultural implement travels.

Non-limiting examples of such materials may be seeds, fertilizers and / or pesticides. It will be appreciated that different types of material may be fed into the same system, and that an agricultural implement may be provided with parallel systems, where for example one may feed seed and another may feed fertilizer or pesticide.

The system 1 comprises a material container 10, which may have a cover 11 in the form of a lid or a tarpaulin. The system further comprises a feed housing 12, which houses a feed rotor 13, which is rotatable in the feed housing 12. The latar rotor 13 can be driven by a drive unit, such as an electric or hydraulic motor (not shown). The latar rotor 13 can be driven directly by the motor or indirectly, for example via a transmission, which may comprise gears, belts or friction wheels. The lath housing 12 has an inlet 121 at its upper portion and an outlet 122 at its lower portion. The inlet 121 connects to a lower portion of the material container 10, so that material contained therein can be fed to the feed housing 12 at least in part by means of gravity. Any additional feeding can be accomplished using a stirrer, auger or fluidized bed. The feed housing 12 houses a feed space 123, which may have a generally cylindrical shape. The latar space 123 has a cylindrical boundary surface 124, the radius of which is approximately equal to or slightly less than a radius of the feed rotor 13. The radially outer portion of the wing blade 131 of the latar rotor may thus abut the cylindrical boundary surface 124. The abutment may be such the wing blades 131 are biased against the cylindrical boundary surface 124. Thus, due to the friction between the wing blades and the cylindrical boundary surface 124, the wing blades may bend slightly while the feed rotor 13 rotates in the feed space 123. at least one of which may have a bushing for a shaft about which the feed rotor 13 is rotatable. This shaft may be a drive shaft, which, as described above, may be connected to the drive unit.

In the case of an axially opposite portion of the feed rotor 13, an axial limiting surface may comprise a bushing and / or bearing for the shaft.

According to a first alternative embodiment, the feed rotor 13 may have a free end of the feeder housing, i.e. no support in the radial direction at the axially opposite portion relative to the drive shaft.

According to a second alternative embodiment, a shaft bushing displacement shaft can be provided at one axial end of the feed rotor 13, while at its other axial end a support is provided in the form of an integral part of the axial limiting surface. The axial outer space 123 may have an axial length equal to, or slightly less than, an axial length of the feed rotor 13. The axially outer portions of the lateral wing blades 131 of the latar rotor may thus abut at least one axial boundary surface 125.

The bearing may be such that the vanes 131 are biased against the axial boundary surface 125. Thus, due to the friction between the vanes and the axial boundary surface, the vanes may bend slightly below that of the feed rotor 13 rotating in the feed space 123, which has an outlet housing 12 having a discharge housing 122. connects to a channel, so that the feed rotor 13 fed material is introduced into the channel 14 via a channel inlet 141.

A pump or fan 15 may be connected to the duct to provide an air flow in the duct 14. At the duct inlet 141, the material may be introduced into the duct so that a material-mixed air stream is provided.

The channel 14 can lead the material directly to one or more discharge parts, for example saw beetles 16a, 16b, 16c or fertilizer beetles.

According to an alternative, a distributor 17 can be arranged for distributing the material-mixed air stream to the saw blades 16a, 16b, 16c. Such distributors are known from, for example, WO2015112086A1. As a further alternative, or complement, one or more singularizing devices 18a, 18b, 18c may be provided to ensure a smoother material flow to the saw blades 16a, 16b, 16c. Such singulating devices are known from, for example, WO2015069179A1. The latar rotor 13 may comprise a rotor core 132 and a plurality of rotor blades 131. The rotor core 132 may be made of a relatively rigid material, such as metal or polymer. In the latter case, the rotor core can be formed of a construction plastic with relatively high rigidity.

The rotor core 132 may be integrated with a motor shaft, i.e. permanently connected to the motor shaft or formed integrally with the motor shaft. Alternatively, the rotor core 132 may be a separate part, which is connected to a motor shaft in such a way that torque from the motor is transferable to the feed rotor 13. The rotor blades 131 may be formed of polymer material of lower stiffness than the material of which the rotor core is formed.

For example, the rotor blades may be formed of an elastic material, such as a rubber-elastic material, for example polyurethane, rubber, thermoplastic elastomer or the like. Elastic materials with hardness Shore A in the order of 30-90, preferably 50-70, have proved suitable.

Preferably, the rotor blades 131 may also be formed of a material which is softer than the material of which the boundary walls 124, 125 of the feed space are formed.

The filter blades 131 may be formed in one piece of material, which may surround and enclose the core 132.

Figs. 2a-2c show a feed rotor 13 according to a first embodiment. The latar rotor 13 has a plurality of rotor blades 131, as well as a core 132. In the example shown, the armator rotor has nine rotor blades.

Fig. 2a shows a perspective view of the feed rotor 13.

Fig. 2b shows the feed rotor in section in a plane comprising the geometric axis of rotation of the feed rotor. Fig. 2b also shows the portion of the core which is intended for attachment to the motor or motor shaft.

Fig. 2c shows an enlarged view of an end portion of the rotor arranged in a feed housing.

The core 132 may be adapted for engagement with a drive shaft (not shown) from a motor (not shown) for driving the feeder. Furthermore, the core 132 may be adapted to connect to, or form part of, a bearing at the relative axial end of the relative motor.

Furthermore, Fig. 2a shows a rotor which is divided into two axially adjacent portions, the rotor blades of which are displaced about 20 ° relative to each other in order to reduce the occurrence of air pulses during the feeding.

The rotor shown in Figs. 2a-2c has a sealing lip 133 which is adapted to act in the radial direction by biasing against a leaky cylindrical surface housed projection 126 from an axial boundary wall 125.

The projection 126 may be adapted to connect to the core 132 to provide storage or support for the rotation of the rotor in the feed space.

The sealing lip 133 is formed in the form of a circumferential, axially tight and radially slightly inwardly projecting portion of elastic material, which may (but must not) be of the same material as the rotor blades are formed of.

Preferably, the sealing lip may define a frustoconical space, the outer opening of which has a slightly smaller inner radius than the outer radius of the projection, so that the sealing lip 133 is biased radially inwards towards the projection 126 and thus provides a good seal.

A gap 134 (Figs. 2b, 2c) may be formed between the axially distal portions of the sealing lip 133 and the axially distal portions of the rotor blades 131 so that the sealing lip and the rotor blades can move independently of each other.

Figs. 3a-3d show a feed rotor 13 "according to an alternative embodiment, where the sealing lip 133 'instead acts substantially axially against an axial limiting surface 125. Apart from the design of the sealing lip 133', the feed rotor according to Figs. 3a-3d is identical to that shown in Figs. 2a-2c.

Fig. 3a shows a perspective view of the feed rotor 13 ", without axial limiting wall.

Fig. 3b shows a further perspective view of the feed rotor 13 ', where the axial end portion of the core 132 is better visible and where also the radial extent of the sealing lip 133' can be seen.

Fig. 3c shows the feed rotor 13 'seen in section.

Fig. 3d shows a detail of the feed rotor 13 'on which the gap 134' of the intermediate sealing lip and the rotor blade 131 is visible, as well as parts of the feed housing 12. Referring to Fig. 3d, the rotor 13 'is rotatable about an axis of rotation C.

A rotor blade 131 extends radially from a core 132 to a cylindrical boundary wall 124 of the feed space 123. According to one embodiment, the distal portion of the rotor blades abuts the cylindrical boundary wall 124. The abutment may be such that the rotor blades 131, when the rotor rotates relative to the follower space 123 the distal portion and the boundary wall 124, are bent backwards, seen in a direction of rotation. Such deflection can amount to 0.5-5 mm, preferably 1-3 mm or 1-2 mm seen in the angular direction.

Viewed in the axial direction, the rotor blades 131 extend to an axial boundary wall 125. Also against the axial boundary wall 125 (preferably both axial boundary walls) the axially distal portion of the rotor blades 131 can lie.

For example, the rotor blades, seen in the axial direction, may extend past one end of the rotor core 132. Furthermore, the abutment may be such that the rotor blades bend relative to the boundary wall 125. Then deflection may amount to 0.5-5 mm, preferably 1-3 mm or 1-2 mm. seen in the tangential direction at the axial and radially distal portion of the rotor blades. The latar rotor 13 'further has a sealing lip 133' for sealing against the denaxial boundary wall 125. In the example shown, the sealing lip 133 'is axially biased against the boundary wall 125 and in sliding contact therewith.

A gap 134 'is provided between the sealing lip 133' and the wing, so that the sealing lip is movable axially towards / from the wall 125 without the action of the wing. Fig. 4 shows a further embodiment of a feed rotor 13 ". In this embodiment, the axially limiting wall 125 has a projection 126 ", which has a conical surface. The latch rotor 13 "has a sealing lip 133", which is similar to that shown in Figs. 2a-2c and 3a-3d and which in this embodiment is biased in a direction perpendicular to the conical surface, i.e. in the direction of axial and horizontal. Also in this embodiment, the feed rotor 13 "has a gap 134" which allows the rotor blade 131 and the sealing lip 133 "to move independently of each other.

Fig. 5 shows a cross section of a rotor blade 131, seen in a plane perpendicular to the radial direction of the rotor 13, 13 ", 13". The filter blade here has an axially set outer portion 135, which is tapered (seen in the axial direction).

By making the rotor blade tapered in this way, the deflection of the rotor blade due to the friction between the rotor blade and the axial restraining surface 125 is facilitated.

It will be appreciated that the embodiment of the rotor blade 131 shown in Fig. 5 may be used on all of the feed rotors shown herein.

The length of the tapered portion may be 1 / 20-1 / 3 of the axial length of the rotor blade, preferably 1 / 10-1 / 5.

Fig. 6 shows a cross section of a rotor blade 131, seen in a plane perpendicular to the counter-rotation axis C of the rotor 13, 13 ", 13". The rotor blade may have a thickness titanium direction, which is constant +/- 5 ° />, preferably +/- 1 ° /> or +/- 0, 1 ° />, over a radial length corresponding to at least half of the rotor 13, 13 ", 13 ”radius, preferably over a length corresponding to at least 2/3 or at least 4/5 of the rotor.

It will be appreciated that the embodiment of the rotor blade 131 shown in Fig. 6 may be used on all of the feed rotors shown herein and also in combination with the embodiment of the rotor blade shown in Fig. 5.

Fig. 7a shows how a central portion of the axial boundary surface 125 may be formed for the purpose of removing dust and small particles which have moved between the sealing lips 133, 133 ", 133" and the boundary surface 125.

In the example shown in Fig. 7a, the limiting surface 125 has been provided with a pair, in relation to the surface 1251 against which the sealing lip abuts, recessed surface portions 1251, one respective edge separating the surfaces 1251, 1252 from each other. A level difference between the surfaces can be in the order of 0.1-2 mm, preferably 0.5-1 mm.

The recessed surface portions extend, seen in the radial direction, between an outer portion, which is outside the abutment surface of the sealing lip 133, 133 ", 133", and an inner portion, which is located inside the abutment lip of the sealing lip.

The edge extends in such a way that material stuck to the intermediate sealing lip 133, 133 ", 133" and the boundary surface, by feeder rotor rotation, is gradually displaced leaky, until it leaves the contact surface of the intermediate sealing lip 133, 133 ", 133" and the boundary surface.

Fig. 7b shows an alternative arrangement, in which a groove 1252 'is arranged to project from the surface 1251 towards the sealing lips 133, 133 ", 133". The groove extends, like the edge in Fig. 7a, between an outer portion, which is located on the abutment surface of the outer sealing lip 133, 133 ", 133", and an inner portion, which is located inside the abutment surface of the sealing lip.

The design of the file is such that material adhered to the intermediate sealing lip 133, 133 ", 133" and the boundary surface, by feeder rotor rotation, is gradually displaced leaky, until it leaves the contact surface of the intermediate sealing lip 133, 133 ", 133" and the boundary surface.

Fig. 7c shows a further alternative arrangement for carrying away dust and small particles which have entered between the sealing lips 133, 133 ", 133" and the limiting surface 125.

The arrangement shown in Fig. 7c comprises two sets of scrapers 1252 ', which can be provided in the form of grooves or bars in the denaxial limiting surface 125.

For example, a set of 1252 ”scrapers can be provided at a wide, vertical direction, upper portion of the feeder. Alternatively, or complementary, a set of 1252 ”scrapers may be provided at a lower portion of the feeder.

Claims (20)

A latar rotor (13, 13 ", 13") for feeding granular or powdered material, comprising: a center portion (132) extending along an axial direction of the feed rotor, and at least two rotor blades (131) extending radially sealed from the center portion, characterized by a sealing lip (133, 133 ", 133") extending around, and axially sealed from, an axial end portion of the center portion, for effecting sealing between the feed rotor (13, 13 ", 13") and a portion (125) which in the axial direction delimits a feed space (123) in which the feed rotor is located. A lathe rotor according to claim 1, wherein the sealing lip (133, 133 ', 133 ") has a proximal portion, to which the sealing lip (133, 133", 133 ") connects the feed rotor (13, 13", 13 ") and a distal portion, which by elasticity the cough sealing lip is movable relative to the feed rotor. A latar rotor according to claim 1 or 2, further comprising a gap (133, 133 ", 133") and the rotor blades (131) located in the gap (134, 134 ', 134 "), the sealing lip (133, 133", 133 " ) are freely movable relative rotor blades. A lathe rotor according to claim 3, wherein the sealing lip (133, 133 ", 133") meets the respective rotor blade (131) at a substantially right angle and the gap (134, 134 ", 134") has a substantially extension perpendicular to the bed rotor blade and the sealing lip. A lathe rotor according to claim 3 or 4, wherein the gap (134, 134 ', 134 ") is tapered in the drawing axially and / or radially inwardly towards the center portion. A latar rotor according to any one of the preceding claims, wherein the sealing lip is designed to provide bias in a radius || direction. A lathe rotor according to any one of the preceding claims, wherein the sealing lip (133, 133 ", 133") is designed to provide prestressing in an axial direction. A lathe rotor according to any one of the preceding claims, wherein at least part of the respective rotor blade is made of an elastic material, preferably rubber-elastic material, such as rubber, thermoplastic elastomer or polyurethane. L \ / latar rotor according to one of the preceding claims, wherein the rotor blades, seen in radius || direction, has a substantially constant cross-sectional area over at least half, preferably at least 2/3 or at least 3A, of its radial length. A lathe rotor according to any one of the preceding claims, wherein the rotor blades, seen in the axial direction, have a portion with a decreasing cross-sectional area in the direction of an axial end of the feed rotor. A charging system for feeding granular or powdered material, comprising: a feed housing (12), which defines a feed space (123), and a feed rotor (13, 13 ", 13") according to any one of the preceding claims, wherein the feed space ( 123) has at least one axial restraint (125), characterized in that the sealing lip (133, 133 ", 133") abuts against the axial restraint (125) so that a sealed space is provided, which extends over a geometric axis of rotation of the feed rotor. The latar system of claim 11, further comprising a projection (126,126 ") extending axially inwardly of the feed space from the axial boundary, the sealing lip (133, 133", 133 ") being radially biased toward a surface of the projection. The latar system of claim 12, wherein the surface is substantially cylindrical or conical. The lathe system of claim 11, wherein the sealing lip (133, 133 ', 133 ") abuts a substantially planar surface of the axial boundary (125), the sealing lip being axially biased toward the planar surface. A charging system according to any one of claims 11 to 14, further comprising at least one scraper portion located between the sealing lip (133, 133 ", 133") and the axial boundary (125), which is arranged to carry dust and particles through the rotation of the feed rotor in the feed housing. which ports between the seal and the axial restraint (125), radially outward. A charger system according to any one of claims 11 to 15, wherein the rotor blades are biased against at least one of the axial restraint (125) and single cylinder sector shaped restraint (124). An agricultural tool (O) for feeding granular or powdered material, comprising: a container (10) for the material, an air flow generating device (11), and a channel (14) connected to the air flow generating device, characterized by a feeding system according to any of claims 11-16, arranged for feeding the material from the container (10) to the air duct (14). Method for feeding granular or powdered material into an agricultural implement, characterized in that causing a feed rotor (13) to rotate in a feed space (123), the part of which is defined by an axial restriction (125), and that by means of a sealing lip (133, 133 ", 133") seal a space between the axial boundary and an axial end of the feed rotor. The method of claim 18, further comprising biasing the sealing lip in the axial and / or radial direction toward the axial boundary. A method according to claim 18 or 19, further comprising, by means of a scraper part located between the sealing lip (133, 133 ", 133") and the axial boundary (125) and rotating the feed housing (12) of the feed rotor, between the seal and the axial boundary, radially leaky.