WO2017061942A1

WO2017061942A1 - Metering rotor for metering granular or powdered material in an agricultural implement, meter system and method for feeding granular or powdered material

Info

Publication number: WO2017061942A1
Application number: PCT/SE2016/050961
Authority: WO
Inventors: Gert Gilstring
Original assignee: Väderstad Holding Ab
Priority date: 2015-10-08
Filing date: 2016-10-06
Publication date: 2017-04-13
Also published as: SE1551296A1; SE539243C2

Abstract

The present document discloses a metering rotor (13, 13', 13") for feeding granular or powdered material in an agricultural implement. The metering rotor comprises a central portion (132), which extends along an axial direction of the metering rotor, and at least two rotor blades (131 ), which extend radially outward from the central portion. The metering rotor has a sealing lip (133, 133', 133"), which extends around, and axially outward from, an axial end portion of the central portion, for providing a seal between the metering rotor (13, 13', 13") and a part (125) which in the axial direction limits a feeder space (123) in which the metering rotor is located. The document also discloses a system for feeding granular or powdered material and a method for feeding granular or powdered material.

Description

METERING ROTOR FOR METERING GRANULAR OR POWDERED MATERIAL IN AN AGRICULTURAL IMPLEMENT, METER SYSTEM AND METHOD FOR FEEDING GRANULAR OR POWDERED MATERIAL

Technical Field

This document relates to a metering rotor for feeding granular or powdered material, which has a use in agricultural implements in particular.

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

Furthermore, the document relates to a method for feeding granular or powdered material in an agricultural implement.

Background

It is known, for example from WO2013180619A1 , in an agricultural implement, to feed granular or powdered material from a material container via a feeder to a channel that takes up the material in an air stream and that feeds the material onward to, for example, a plurality of furrow openers.

The feeder comprises a feeder housing, in which a metering rotor is rotatably disposed.

The air stream is typically achieved by a fan or a pump, which produces an overpressure in the channel that leads the air stream.

It is desirable to ensure that the overpressure is maintained in the entire channel in order to reduce energy consumption, and it is a challenge to introduce the material in the channel without losing the overpressure.

One way of achieving this is to provide the material container with a seal-tight lid, so that the overpressure is maintained all the way up in the material container.

Another way of achieving this is to utilize an injector, in which a vacuum suction to the channel is achieved according to the Venturi principle. Another method is to provide a feeder that acts as an air lock and thus prevents the overpressure in the channel from leaking up into the material container, allowing normal pressure in the material container.

Normal pressure in the material container is advantageous, since it is difficult to provide a large material container with a similarly large lid which is sufficiently seal-tight.

One problem is that the environment in which the agricultural implement is used and the material being fed often give rise to large amounts of dust and dirt, which makes it difficult to achieve good seal-tightness.

It is also desirable to reduce the energy consumption of the agricultural implement. In addition, it is desirable to reduce the cost and weight of the agricultural implement, for example by using electric motors, preferably electric motors that are not too big.

Based on the fact that it is desirable to provide a feeder that acts as an air lock, there is a need for an improved feeder, in particular a feeder which reduces air leakage in a reverse direction from the feeder outlet to the feeder inlet.

Summary

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

The invention is defined in the independent claims. Embodiments are set forth in the dependent claims, in the description that follows and in the drawings.

According to a first aspect, a metering rotor for feeding granular or powdered material is provided, comprising a central portion, which extends along an axial direction of the metering rotor, and at least two rotor blades, which extend radially outward from the central portion. The metering rotor has a sealing lip which extends around, and axially outward from, an axial end portion of the central portion, for providing a seal between the metering rotor and a part which in the axial direction limits a feeder space in which the metering rotor is located. "Central portion" refers to a central portion of the metering rotor. This can be made in one piece with and of the same material as the metering rotor.

Alternatively, the central portion can be made of another material than the rest of the rotor, for example a stiffer material.

The sealing lip reduces leakage beyond the metering rotor central portion, from the material outlet to the material inlet. A sealing lip can also be made with a high degree of precision, so that its bearing 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 metering rotor is rotatable.

The sealing lip can have a proximal portion, at which the sealing lip connects to the metering rotor, and a distal portion, which, through elasticity of the sealing lip, is movable relative to the metering rotor.

Moreover, the metering rotor can comprise a gap located between the sealing lip and the rotor blades, wherein the sealing lip is freely movable relative to the rotor blades.

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

The gap can be tapered axially and/or radially inward toward the central portion.

The sealing lip can be formed to provide pre-tension in a radial direction.

Alternatively, or as a complement, the sealing lip can be formed to provide pre-tension in an axial direction.

At least a part of each rotor blade can be made of an elastic material, preferably a rubber elastic material, such as rubber, thermoplastic elastomer or polyurethane.

For example, the rotor blades can be made entirely of an elastic material. Alternatively, the radial and/or axial outer portions of the rotor blades can be made of an elastic material. Such elastic portions can deflect as a result of the friction with the wall they bear upon. The rotor blades, viewed in a radial direction, can have a substantially constant cross-sectional area across at least half, preferably at least 2/3 or at least 3/4, of their radial length.

Alternatively, or as a complement, the rotor blades, viewed in an axial direction, can have a portion with a declining cross-sectional area in the direction toward an axial end of the metering rotor.

Preferably, the portion extends across at least 1 /10 or at least 1 /5 of the axial length of the rotor blades. Such a declining cross-sectional area reduces the bearing force while allowing the rotor blades to bend out.

According to a second aspect, a metering system for feeding granular or powdered material is provided, comprising a feeder housing, which defines a feeder space, and a metering rotor as described above. The feeder space has at least one axial limitation. The sealing lip bears on the axial limitation so that a sealed space is provided, which extends around a geometrical rotational axis of the metering rotor.

The sealed space can be rotationally symmetrical.

Moreover, the metering system can comprise a protrusion which extends axially inward in the feeder space from the axial limitation, wherein the sealing lip is radially pre-tensioned against a surface of the protrusion.

The surface can be substantially cylindrical or conical.

Alternatively, the sealing lip can bear on a substantially planar surface of the axial limitation, wherein the sealing lip can be axially pre-tensioned against the planar surface.

Moreover, the metering system can comprise at least one scraper part, which is located between the sealing lip and the axial limitation and, through the rotation of the metering rotor in the feeder housing, is arranged to carry dust and particles radially outward from between the seal and the axial limitation.

The scraper part can comprise an edge, which extends at an angle to the radius of the sealing lip, so that the rotation of the metering rotor causes dust and particles to migrate radially outward and away from the area between the axial limitation and the sealing lip. In one embodiment, the rotor blades can be pre-tensioned against at least one of the axial limitation and a cylindrical sector shaped limitation.

By pre-tensioning the rotor blades, a sealed bearing can be provided, which reduces or prevents air leakage in the direction from the material outlet to the material inlet.

According to a third aspect, an agricultural implement for feeding granular or powdered material is provided, 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 metering system as described above, arranged for feeding the material from the container to the air channel.

According to a fourth aspect, a method for feeding granular or powdered material in an agricultural implement is provided, comprising causing a metering rotor to rotate in a feeder space, which in part is defined by an axial limitation, and using a sealing lip to seal a space between the axial limitation and an axial end of the metering rotor.

The method can further comprise pre-tensioning the sealing lip axially and/or radially toward the axial limitation.

The method can further comprise using a scraper part, located between the sealing lip and the axial limitation, and the rotation of the metering rotor in the feeder housing, to carry dust and particles radially outward from between the seal and the axial limitation.

Brief description of the drawings

Fig 1 is a schematic view of a metering system 1 for feeding granular or powdered material.

Figs 2a-2c show a metering rotor according to a first embodiment.

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

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

Fig 5 shows a connection between a wing blade of a metering rotor according to any one of the embodiments and an axial wall of the feeder space. Fig 6 shows a connection between a wing blade of a metering rotor according to any one of the embodiments and a cylindrical wall of the feeder space.

Figs 7a-7c show various embodiments of arrangements for cleaning the seal between the metering rotor and the axial limitation.

Detailed description

In Fig 1 , a metering system 1 is shown, which can be supported by an agricultural implement 0 and thus be used for distribution of granular or powdered material on the ground on which the agricultural implement is traveling.

A non-limiting example of a material of this kind can be seed, fertilizer and/or pesticides. It will be appreciated that different types of material can be fed in the same system, and that an agricultural implement can be equipped with parallel systems where, for example, one feeds seeds and another feeds fertilizer or pesticides.

The system 1 comprises a material container 10, which can have a cover 1 1 in the form of a lid or a tarpaulin. The system further comprises a feeder housing 12, which includes a metering rotor 13 which is rotatable in the feeder housing 12.

The metering rotor 13 can be driven by a drive unit, such as an electric or hydraulic motor (not shown). The metering rotor 13 can be driven directly by the motor or indirectly, for example via a transmission which can comprise gears, belts or friction wheels.

The feeder 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 in this can be fed to the feeder housing 12, at least partly using gravitation. Additional feeding can possibly be provided using an agitator, a feed screw or a fluidized bed.

The feeder housing 12 includes a feeder space 123, which can have a generally cylindrical form. The feeder space 123 has a cylindrical limit surface 124, whose radius is approximately equal in size to, or somewhat smaller than, a radius of the metering rotor 13.

The radial outer portion of the wing blades 131 of the metering rotor can thus bear upon the cylindrical limit surface 124. The bearing can be such that the wing blades 131 are pre-tensioned against the cylindrical limit surface 124. Therefore, the wing blades, as a result of the friction between the wing blades and the cylindrical limit surface 124, can bend out a little while the metering rotor 13 rotates in the feeder space 123.

The feeder space 123 can also have axial limit surfaces 125, of which at least one can have a bushing for an axle around which the metering rotor 13 is rotatable. This axle can be a drive axle which, as described above, can be connected to the drive unit.

In the event of an axial opposite portion of the metering rotor 13, an axial limit surface can comprise a bushing and/or bearing for the axle.

According to a first alternative embodiment, the metering rotor 13 can have a free end in the feeder housing, i.e. no support in the radial direction in the event of an axial opposite portion relative to the drive axle.

According to a second alternative embodiment, an axle bushing for a drive axle can be provided at one of the axial ends of the metering rotor 13, while at its other axial end a support in the form of an integrated part of an axial limit surface is provided.

The feeder space 123 can have an axial length which is equal in size to, or somewhat smaller than, an axial length of the metering rotor 13.

The axial outer portions of the wing blades 131 of the metering rotor can thus bear upon at least the one axial limit surface 125.

The bearing can be such that the wing blades 131 are pre-tensioned against the axial limit surface 125. Therefore, the wing blades, as a result of the friction between the wing blades and the axial limit surface, can bend out a little while the metering rotor 13 rotates in the feeder space 123.

The metering housing 12 has an outlet 122, which connects to a channel, so that material fed by the metering rotor 13 is introduced into the channel 14 via a channel inlet 141 . A pump or a fan 15 can be connected to the channel to provide an air stream in the channel 14. At the channel inlet 141 , the material can be introduced into the channel so that an air stream mixed with material is achieved.

The channel 14 can lead the material directly to one or several feed- out parts, for example furrow openers 16a, 16b, 16c or fertilizer openers.

According to one alternative, a distributor 17 can be arranged for distributing the air stream mixed with material to the furrow openers 16a, 16b, 16c. Such distributors are known from, for example, WO20151 12086A1 .

As an additional alternative, or complement, one or more singulating devices 18a, 18b, 18c can be arranged to ensure a more even flow of material to the furrow openers 16a, 16b, 16c. Such singulating devices are known from, for example, WO2015069179A1 .

The metering rotor 13 can comprise a rotor core 132 and a plurality of rotor blades 131 . The rotor core 132 can be made of a relatively stiff material, such as metal or polymer. In the latter case, the rotor core can be made of a construction plastic with a relatively high stiffness.

The rotor core 132 can be integrated with a motor shaft, i.e.

permanently connected to the motor shaft or made in one piece together with the motor shaft. Alternatively, the rotor core 132 can be a separate part, which is connected to a motor shaft in such a manner that torque from the motor is transferable to the metering rotor 13. The rotor blades 131 can be made of polymer material with a lower stiffness than the material that the rotor core is made of.

For example, the rotor blades can be made of an elastic material, such as a rubber elastic material, for example polyurethane, rubber, thermoplastic elastomer or similar. Elastic materials with hardness Shore A in ranges of 30- 90, preferably 50-70, have proven to be suitable.

Preferably, the rotor blades 131 can also be made of a material which is softer than the material that the limitation walls 124, 125 of the feeder space are made of.

The rotor blades 131 can be made in one piece of material, which can surround and enclose the core 132. Figs 2a-2c show a metering rotor 13 according to a first embodiment. The metering rotor 13 has a plurality of rotor blades 131 , and a core 132. In the example shown, the metering rotor has nine rotor blades.

In Fig 2a, a perspective view of the metering rotor 13 is shown.

Fig 2b shows the metering rotor in section in a plane comprising the geometrical rotational axis of the metering rotor. The portion of the core which is intended for attachment to the motor or the motor shaft is also shown in Fig 2b.

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

The core 132 can be adapted for connection to a drive axle (not shown) from a motor (not shown) for driving the feeder. Moreover, the core 132 can be adapted to connect to, or be a part of, a bearing at an opposite axial end relative to the motor.

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

The rotor shown in Figs 2a-2c has a sealing lip 133 which is adapted to act in radial direction by being pre-tensioned against an outward cylindrical surface of a protrusion 126 from an axial limitation wall 125.

The protrusion 126 can be adapted to connect to the core 132 in order to provide a bearing or support for the rotation of the rotor in the feeder space.

The sealing lip 133 is formed in the form of a circumferential, axially outward and radially somewhat inward projecting portion of elastic material, which can be (but does not have to be) of the same material as the rotor blades.

Preferably, the sealing lip can define a frustoconical space, whose outer opening has a somewhat smaller inner radius than the outer radius of the protrusion, so that the sealing lip 133 is pre-tensioned radially inward against the protrusion 126 and thus provides a good seal. A gap 134 (Figs 2b, 2c) can be formed between 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 metering rotor 13' according to an alternative embodiment, where the sealing lip 133' instead acts substantially axially against an axial limit surface 125. Apart from the design of the sealing lip 133', the metering rotor according to Figs 3a-3d is identical to the

embodiment shown in Figs 2a-2c.

Fig 3a shows a perspective view of the metering rotor 13', without an axial limitation wall.

Fig 3b shows an additional perspective view of the metering rotor 13', where the axial end portion of the core 132 is more visible and where the radial extension of the sealing lip 133' can also be seen.

Fig 3c shows the metering rotor 13' viewed in section.

Fig 3d shows a detail of the metering rotor 13' where the gap 134' between the sealing lip and the rotor blade 131 is visible, and also parts of the feeder housing 12.

With reference to Fig 3d, the rotor 13' is rotatable around a rotational axis C.

A rotor blade 131 extends radially from a core 132 to a cylindrical limitation wall 124 of the feeder space 123. According to one embodiment, the distal portion of the rotor blades bears on the cylindrical limitation wall 124. The bearing can be such that the rotor blades 131 , when the rotor rotates relative to the feeder space 123, as a result of the friction between the distal portion and the limitation wall 124, deflect rearward, viewed in a direction of rotation. Such a deflection can amount to 0.5-5 mm, preferably 1 -3 mm or 1 -2 mm viewed in a tangential direction.

Viewed in an axial direction, the rotor blades 131 extend to an axial limitation wall 125.

The axially distal portion of the rotor blades 131 can also bear on the axial limitation wall 125 (preferably both axial limitation walls).

For example, the rotor blades, viewed in an axial direction, can extend beyond an end of the rotor core 132. Moreover, the bearing can be such that the rotor blades deflect relative to the limitation wall 125. Such a deflection can amount to 0.5-5 mm, preferably 1 -3 mm or 1 -2 mm, viewed in a tangential direction at the axially and radially distal portion of the rotor blades.

Moreover, the metering rotor 13' has a sealing lip 133' for sealing against the axial limitation wall 125.

In the example shown, the sealing lip 133' is axially pre-tensioned against the limitation wall 125, and in sliding contact thereto.

A gap 134' is arranged between the sealing lip 133' and the wing, so that the sealing lip is moveable axially toward/from the wall 125 without any effect from the wing.

Fig 4 shows an additional embodiment of a metering rotor 13". In this embodiment, the axial limitation wall 125 has a protrusion 126', with a conical surface. The metering rotor 13" has a sealing lip 133", which is similar to the one shown in Figs 2a-2c and 3a-3d, and which in this embodiment is pre- tensioned in a perpendicular direction to the conical surface, i.e. in an axial and horizontal direction. Also in this embodiment, the metering 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 , viewed in a plane perpendicular to a radial direction of the rotor 13, 13', 13". The rotor blade has here, in an axial view, an outer portion 135, which is tapered outward (viewed in an axial direction).

By making the rotor blade tapered in this manner, the deflection of the rotor blade is facilitated as a result of the friction between the rotor blade and the axial limitation surface 125.

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

The length of the tapered portion can 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 , viewed in a plane perpendicular to the rotational axis C of the rotor 13, 13', 13". The rotor blade can have a thickness in the tangential direction, which is constant +/- 5%, preferably +/- 1 % or +/- 0.1 %, across a radial length corresponding to at least half of the radius of the rotor 13, 13', 13", preferably across a length corresponding to at least 2/3 or at least 4/5 of the radius of the rotor.

It will be appreciated that the embodiment of the rotor blade 131 , shown in Fig 6, can be used on all metering 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 limitation surface 125 can be designed in order to remove dust and small particles which have entered between the sealing lip 133, 133', 133" and the limitation surface 125.

In the example shown in Fig 7a, the limitation surface 125 has been provided with, in relation to the surface 1251 which the sealing lip bears upon, a pair of recessed surface portions 1251 , wherein a respective edge separates the surfaces 1251 , 1252 from each other. A difference in level between the surfaces can be in the range of 0.1 -2 mm, preferably 0.5-1 mm.

The recessed surface portions extend, viewed in a radial direction, between an outer portion, which is outside the bearing surface of the sealing lip 133, 133', 133", and an inner portion, which is inside the bearing surface of the sealing lip.

The edge extends in such a way that material that is stuck between the sealing lip 133, 133', 133" and the limitation surface, through the rotation of the metering rotor, is gradually displaced outward, until it leaves the bearing surface between the sealing lip 133, 133', 133" and the limitation surface.

Fig 7b shows an alternative arrangement, where a groove 1252' is arranged to project out from the surface 1251 toward the sealing lip 133, 133', 133". The groove extends, like the edge in Fig 7a, between an outer portion, which is outside the bearing surface of the sealing lip 133, 133', 133", and an inner portion, which is inside the bearing surface of the sealing lip.

The design of the groove is such that material that is stuck between the sealing lip 133, 133', 133" and the limitation surface, through the rotation of the metering rotor, is gradually displaced outward, until it leaves the bearing surface between the sealing lip 133, 133', 133" and the limitation surface. Fig 7c shows an additional alternative arrangement for removing dust and small particles which have entered between the sealing lip 133, 133', 133" and the limitation surface 125.

The arrangement shown in Fig 7c comprises two sets of scrapers 1252", which can be provided in the form of grooves or slots in the axial limitation surface 125.

For example, a set of scrapers 1252" can be provided, viewed in a vertical direction, at an upper portion of the feeder. As an alternative, or as a complement, a set of scrapers 1252" can be provided at a lower portion of the feeder.

Claims

PATENT CLAIMS

1 . A metering rotor (13, 13', 13") for feeding granular or powdered material, comprising:

a central portion (132), which extends along an axial direction of the metering rotor, and

at least two rotor blades (131 ), which extend radially outward from the central portion,

characterized by

a sealing lip (133, 133', 133"), which extends around, and axially outward from, an axial end portion of the central portion, for providing a seal between the metering rotor (13, 13', 13") and a part (125) which in the axial direction limits a feeder space (123) in which the metering rotor is located.

2. The metering rotor according to claim 1 , wherein the sealing lip (133, 133', 133") has a proximal portion, at which the sealing lip (133, 133',

133") connects to the metering rotor (13, 13', 13"), and a distal portion, which, through elasticity of the sealing lip, is movable relative to the metering rotor.

3. The metering rotor according to claim 1 or 2, further comprising a gap (134, 134', 134") located between the sealing lip (133, 133', 133") and the rotor blades (131 ), wherein the sealing lip (133, 133', 133") is freely movable relative to the rotor blades.

4. The metering rotor according to claim 3, wherein the sealing lip (133, 133', 133") meets each rotor blade (131 ) at a substantially right angle, and wherein the gap (134, 134', 134") has a principal extension perpendicular to the rotor blade and the sealing lip.

5. The metering rotor according to claim 3 or 4, wherein the gap (134, 134', 134") is tapered axially and/or radially inward toward the central portion.

6. The metering rotor according to any one of the preceding claims, wherein the sealing lip is formed to provide pre-tension in a radial direction.

7. The metering rotor according to any one of the preceding claims, wherein the sealing lip (133, 133', 133") is formed to provide pretension in an axial direction.

8. The metering rotor according to any one of the preceding claims, wherein at least a part of each rotor blade is made of an elastic material, preferably a rubber elastic material, such as rubber, thermoplastic elastomer or polyurethane.

9. The metering rotor according to any one of the preceding claims, wherein the rotor blades, viewed in a radial direction, have a substantially constant cross-sectional area across at least half, preferably at least 2/3 or at least 3/4, of their radial length.

10. The metering rotor according to any one of the preceding claims, wherein the rotor blades, viewed in an axial direction, have a portion with a declining cross-sectional area in the direction toward an axial end of the metering rotor.

1 1 . A metering system for feeding granular or powdered material, comprising:

a feeder housing (12), which defines a feeder space (123), and a metering rotor (13, 13', 13") according to any one of the preceding claims,

the feeder space (123) having at least one axial limitation (125), characterized by

that the sealing lip (133, 133', 133") bears on the axial limitation (125) so that a sealed space is provided, which extends around a geometrical rotational axis of the metering rotor.

12. The metering system according to claim 1 1 , further comprising a protrusion (126, 126') which extends axially inward in the feeder space from the axial limitation, wherein the sealing lip (133, 133', 133") is radially pre- tensioned against a surface of the protrusion.

13. The metering system according to claim 12, wherein the surface is substantially cylindrical or conical.

14. The metering system according to claim 1 1 , wherein the sealing lip (133, 133', 133") bears on a substantially planar surface of the axial limitation (125), wherein the sealing lip is axially pre-tensioned against the planar surface.

15. The metering system according to any one of claims 1 1 -14, further comprising at least one scraper part, which is located between the sealing lip (133, 133', 133") and the axial limitation (125) and, through the rotation of the metering rotor in the feeder housing, is arranged to carry dust and particles radially outward from between the seal and the axial limitation (125).

16. The metering system according to any one of claims 1 1 -15, wherein the rotor blades are pre-tensioned against at least one of the axial limitation (125) and a cylindrical sector shaped limitation (124).

17. An agricultural implement (0) for feeding granular or powdered material, comprising:

a container (10) for the material,

an air flow generating device (1 1 ), and

a channel (14) connected to the air flow generating device,

characterized by

a metering system according to any one of claims 1 1 -16, arranged for feeding the material from the container (10) to the air channel (14).

18. A method for feeding granular or powdered material in an agricultural implement, comprising:

causing a metering rotor (13) to rotate in a feeder space (123), which in part is defined by an axial limitation (125), and

using a sealing lip (133, 133', 133") to seal a space between the axial limitation and an axial end of the metering rotor.

19. The method according to claim 18, further comprising pre- tensioning the sealing lip axially and/or radially toward the axial limitation.

20. The method according to claim 18 or 19, further comprising using a scraper part, located between the sealing lip (133, 133', 133") and the axial limitation (125), and the rotation of the metering rotor in the feeder housing (12), to carry dust and particles radially outward from between the seal and the axial limitation.