GB2056241A

GB2056241A - Cleaning device for harvesting machines

Info

Publication number: GB2056241A
Application number: GB8025156A
Authority: GB
Original assignee: Deere and Co
Current assignee: Deere and Co
Priority date: 1979-08-04
Filing date: 1980-08-01
Publication date: 1981-03-18
Also published as: DE2931767C2; FR2462855B1; GB2056241B; FR2462855A1; DE2931767A1

Abstract

In a cleaning device for threshed crop material the material is introduced into a drum 2, e.g. by a coaxial auger feeder 24. An air flow whirling around the inner wall of the drum is created by a blower 4 with a tangentially connected input connection 6. Heavy crop material (grain) tends to be flung against the drum wall and leaves through a grille into a closed conveyor system 14, 16 creating dynamic air pressure in the drum. Chaff and straw tend to be held in vortex in the central core of the drum and leave axially through one drum end. <IMAGE>

Description

SPECIFICATION Cleaning device for harvesting machines The invention relates to a cleaning device for harvesting machines wherein a blower subjects a cleaning drum to cleaning air, which is conveyed into the drum and which separates the harvested crops from impurities, the harvested crops being discharged through sieve-like outlets provided in the cleaning drum.

One known cleaning device (German Offenlegungsschrift 1,457,968) is provided at the end of a threshing and separating drum and is formed of a sieve-like housing in which there is provided a rotatably mounted conveying element which keeps the harvested crops and the impurities moving in the housing, the cleaning housing being subjected to air by way of a blower so that the impurities can be separated from the harvested crops. The blower is in this case connected to the cleaning housing in such a way that the cleaning air is conveyed radially to the cleaning housing. Optimum separation of the impurities from the harvested crops is impossible because of this arrangement of the cleaning blower.

It is the object of the present invention to separate the harvested crops from the impurities by centrifugal means.

According to the present invention, there is provided cleaning device for harvesting machines comprising a cleaning drum, a feeder for feeding threshed material into the drum and a blower for subjected the cleaning drum to cleaning air which is conveyed into the drum through at least one inlet and which separates the harvested crops from impurities, the harvested crops being discharged through at least one sieve-like outlet provided in the cleaning drum, the blower being approximately tangentially connected to the cleaning drum by its pressure connection in such a way that the cleaning air is conveyed, with the harvested crops, along the closed inner wall of the cleaning drum, the cleaned harvested crops being discharged through the outlet(s) which are provided on the wall of and/or at the end of the cleaning drum.Since the cleaning air is conveyed tangentially into the cleaning drum, the material mixture of harvested crops and impurities is caused to rotate and in this case is moved mainly along the inner wall of the cleaning drum. An artificial force field is created hereby, and the heavier parts, i.e. the harvested crops, are forced outwards against the inner wall of the cleaning drum, whilst the lighter parts, namely the impurities, move more towards the centre of the cleaning drum. In this way it is possible for the harvested crops to be discharged through the outlet or outlets provided on the wall of the cleaning drum. This arrangement therefore completely prevents the discharge of impurities through the outlets since the impurities are discharged from the cleaning drum mainly in the axial direction.In this case it is advantageous that the outlet for the cleaned harvested crops is sealed by a device which generates a dynamic pressure, and that the device generating the dynamic pressure is a conveying device for receiving the cleaned harvested crops. The device which generates the dynamic pressure is intended to prevent the cleaning air from being able to escape together with the harvested crops and from also discharging impurities. This device therefore ensures that the harvested crops are moved by centrifugal means along the inner wall of the cleaning drum and are only discharged through the outlet after the impurities are separated from the crops.

In accordance with a further feature of the invention it is advantageous that the outlet, seen in the conveying direction, lies directly behind the inlet of the blower, and that the width of one blower or of a plurality of blowers arranged side by side is to some extent equal to the length of the cleaning drum. In this way it is ensured that the harvested crops must pass, together with the impurities, through the entering stream of cleaning air so that the lighter parts can then be blown off towards the interior, whilst the heavier parts can be discharged towards the exterior.

Moreover, it is advantageous that the outlet can be divided into sections by means of a separating device through which harvested crops, which have been cleaned to varying degrees, can be fed to various conveying devices, and that the second outlet, which is formed by means of the separating device, is provided, relative to the conveying direction of the harvested crops, in the rear section of the cleaning drum or in an extension of the cleaning drum. It is ensured by means of the separating device that harvested crops, which have been cleaned to varying degrees, can be fed to various conveying devices, it being possible for the harvested crops, which have been cleaned to a lesser degree, to be fed back to the cleaning device.Moreover, it is advantageous that the end of the feeder for the harvested crops is situated in the front section of the cleaning drum, the outlet of the cleaning drum is covered by a device having longitudinal orifices, and that the device is in the form of a finger rake, the tines of which form an angle to the plane which extends in the flow direction of the air. Moreover, it is advantageous that the finger rake is curve-shaped and designed so as to be adjustable, and that the tines of the finger rakes are spaced from one another by a variable distance. Moreover, it is advantageous that the finger rake is detachably connected to the cleaning drum. Mechanical separation, in addition to pneumatic separation of the harvested crops from the impurities, is ensured by using the finger rake.In this case it is advantageous that a plurality of finger rakes, which are arranged at intervals from one another when seen in the peripheral direction, are provided on the inner wall of the cleaning drum, the said rakes being spaced, at their delivery ends, from the inner wall of the cleaning drum.

In accordance with a further feature of the invention it is advantageous that at least one adjustable guide device is provided in the area of the pressure connection of the cleaning blower, and that the device for conveying the cleaned harvested crops comprises, in the area of its inlet connection, an adjustable guide device, the front end of which can be pivoted into the cleaning drum. The adjustable guide device ensures that the impurities are conveyed more or less towards the inner area of the cleaning drum, depending on the quality of the harvested crops. in this case it is advantageous that at least two blowers, spaced at intervals from one another, or groups of blowers are distributed on the circumference of the cleaning drum.Moreover, it is advantageous that the cleaning drum comprises a plurality of inlets distributed on the circumference thereof and is at least partially surrounded by an outer, closed jacket which forms an annular channel, the annular channel being connected by its air inlet to at least one blower, that a finger rake is associated with each inlet, the finger rake above the outlet being larger than the other finger rakes, and that the adjustable guide device is provided on the annular channel in the area of its air outlet.

Moreover, it is advantageous that the inlet for the cleaning air is provided with the largest inlet cross-section and the outlet for the cleaned harvested crops is provided in the upper section of the cleaning drum.

In accordance with a further feature of the invention it is advantageous that the feeder for the harvested crops is mounted coaxially with the cleaning drum and is followed by a rotary conveying device which comprises blades and which is mounted concentrically with the feeder.

Because of the additional arrangement of a further rotary conveying device, which can be installed in the system after, for example, a screw conveyor, the harvested crops are also caused to rotate in the cleaning drum by mechanical means in a simple manner. In this case it is advantageous that the feeder is connected by its outlet connection to the pressure connection of the blower, the outlet connection lying, relative to the conveying direction in the cleaning drum, in a transverse plane which extends through the front part of the cleaning drum.

In accordance with a further feature of the invention it is advantageous that a threshing and separating device, which extends coaxially with the cleaning drum, runs into the front section of the said drum. The entire device has a more compact construction because the cleaning device is mounted coaxially with the threshing and separating device.

Moreover, it is advantageous that the finger rake extends over the entire width of all the outlets for the cleaned harvested crops and at least partially covers the outlets in the conveying direction of the harvested crops, and that the blower is connected, relative to the conveying direction of the harvested crops, to the end of the cleaning drum by a suction connection, the pressure connection of the said blower being connected to the annular channel. It is also advantageous that the outlet for impurities is provided on the wall of the cleaning drum, and that the suction connection of the blower extends coaxially with the cleaning drum. Owing to the coaxial arrangement of the blower at the end of the cleaning drum, the power input can be reduced since a rotary motion has already been imparted to the cleaning air entering the blower.

Moreover, it is then advantageous that the impurities at the end of the cleaning drum are discharged laterally.

Several exemplary embodiments of a cleaning device according to the invention are explained with the aid of the drawing. In the drawing: Figure 1 shows a diagrammatic section of a cleaning device in side view, Figure 2 shows a plan view of the cleaning device according to Figure 1, Figure 3 shows a further exemplary embodiment of the cleaning device, in side view, Figure 4 shows a plan view of the cleaning device according to Figure 3, Figure 5 shows a third exemplary embodiment of the cleaning device, in side view, Figure 6 shows a fourth exemplary embodiment of the cleaning device, in side view, Figure 7 shows a fifth exemplary embodiment of the cleaning device, in side view, having a plurality of finger rakes distributed over the circumference, Figure 8 shows a sixth exemplary embodiment of the cleaning device, in side view, having a housing, situated in the upper area of the cleaning device, for conveying cleaned harvested crops, Figure 9 shows a seventh exemplary embodiment of the cleaning device, in plan view, having an additional rotary conveying device which is arranged after the feeder, Figure 10 shows an eighth exemplary embodiment of the cleaning device, in side view, the outlet connection of the feeder leading into the pressure connection of the blower, Figure 11 shows a ninth exemplary embodiment of the cleaning device, in side view, a threshing and separating device being partly integrated in the cleaning drum, Figure 12 shows a plan view of the cleaning device according to Figure 11, Figure 13 shows a tenth exemplary embodiment of the cleaning device, in plan view, the cleaning blower being mounted at the-end of and coaxially with the cleaning drum.

In the drawing, 2 designates a cleaning drum of a cleaning device for harvesting machines, it being possible for the cleaning device to be used also in combine harvesters. The cleaning drum 2 is cylindrically shaped in the exemplary embodiment, it being also possible for the cleaning drum to be oval-shaped or cone-shaped. Connected to the cleaning drum 2 is a blower 4 which is connected tangentially to the cleaning drum 2 via a pressure connection 6. In this case the pressure connection 6, as shown in Figure 1, is connected to the lower wall of the cleaning drum. In this way the cleaning air emerging from the pressure connection 6 is conducted into the cleaning drum 2 through an inlet 7 provided in the wall of the cleaning drum 2 and is then moved tangentially along the inner wall 8 of the cleaning drum 2, the harvested crops also being conveyed along with the impurities.

Behind the inlet 7 there is provided in the cleaning drum a lateral outlet 10 to which an inlet connection 12 of a conveying device 14 is connected. The conveying device 14 serves to receive the cleaned harvested crops and for this purpose comprises a screw conveyor 16 which can carry the harvested crops directly or indirectly to a storage tank (not shown in the drawing). The harvested crops, which are delivered, for example, from a threshing and separating device 20 (Figures 11 and 12), pass through a feeder 18 and through an outlet connection 22 into the cleaning drum 2. As shown in Figure 2, the feeder 18 is equipped with an auger conveyor 24 which extends coaxially with the cleaning drum 2 and, as a result, delivers the harvested crops to the centre of the cleaning drum. A scraper conveyor or other conveyor can also be provided in place of the auger conveyor 24.The cleaning drum 2 comprises, in addition to the first outlet 10, a second outlet 26 which is separated from the first outlet 10 by means of a separating device, for example a partition 28. The outlet 10 provides access to the conveyor housing 30 and the outlet 26 provides access to the conveyor housing 32.

The conveyor housing 30 can be connected to the storage tank, whilst the conveyor housing 32 can be connected to the housing of the threshing and separating device 20. In this way the harvested crops which have been only partially cleaned are fed back to the cleaning device. In place of the blower 4 shown in Figure 1, a plurality of blowers 4' arranged side by side can be connected, as shown in Figure 2, to the cleaning drum 2, the said blowers being mounted on a drive shaft 34 and driven by means of a V-belt pulley 36. Each blower 4' is connected to an inlet 7' which is provided on the wall of the cleaning drum 2. Chaff and other impurities are moved tangentially and axially along the inner wall 8 until they pass out of the cleaning drum 2 through an opening 70 at the end thereof.

As shown in Figure 3, the inlet 7 or 7' can be covered at least partially by a sieve-like grill (not shown in the drawing) or by a finger rake 38. The finger rake 38 consists of a large number of tines 40 which are arranged side by side and extend parallel to one another, it being possible to have a variable spacing between the said tines. The widest spacing between the tines 40 occurs in the area above the second outlet 26 so that ears of grain, which have not been threshed or which have only been partially threshed, can be discharged more efficiently, the said ears of grain then being fed back to the cleaning device.The tines 40 shown in Figure 4 form an acute angle relative to the transverse plane which intersects the cleaning drum 2 so that the harvested crops which have been conveyed past the inner wall 8 of the cleaning drum 2 are also deflected laterally. This ensures that the harvested crops are conveyed more efficiently to the end of the cleaning drum 2. The entire surface area of the finger rake 38 covers the entire area of the inlets, designated by 7', and, to some extent, the outlets 10 and 26. The coarser impurities of the harvested crops, for example straw, are hereby deflected from the outlets 10 and 26 so that they cannot be discharged.As shown in Figures 3 and 5, the pressure connection 6 of the blower 4 or 4' is equipped with an adjustable or pivotable guide device 42 which influences the direction in which the cleaning air flowing out of the blower is injected so that impurities in the harvested crops can be conveyed with a relatively strong force towards the central area of the cleaning drum.

This also makes possible adaptation to different types of harvested crops.

In accordance with a further exemplary embodiment according to Figure 5 it is possible to provide, relative to the direction of rotation, a plurality of finger rakes 38 arranged at intervals from one another on the inner wall 8 of the cleaning drum, which finger rakes point inwards with their free ends and thereby guide coarser impurities of the harvested crops into the central area of the cleaning drum and also produce an agitating effect in the mixture of crops and impurities, whereby the harevested crops, for example corn, can be shaken out of the straw layer. The overall length of the finger rakes 38 is in this case less than the overall length of the finger rake 38 above the inlet 7. Moreover, it is possible to provide, in addition to the first blower 4, a second blower 44 which is approximately on a level with the first blower 4.The blower 44 is also connected tangentially to the wall of the cleaning drum 2 by its pressure connection 46, which makes it possible to produce a further effect for separating the mixture of crops and impurities. In accordance with a further exemplary embodiment shown in Figure 6, the inlet connection 12 of the conveying device 14 is equipped with a pivotable guide device 48 which, when in certain positions, extends with its front end 50 into the cleaning drum 2. With the aid of the guide device 48 it is possible to divert impurities more or less away from the conveying device 14 so that this means also makes it possible to adapt the cleaning device to different types of harvested crops.

In accordance with a further exemplary embodiment shown in Figure 7 the cleaning drum 2 can be surrounded by a further outer jacket 52 which forms, with the outer wall of the cleaning drum 2, an annular channel 54 which is connected by its air inlet 56 to the blower 4. In this exemplary embodiment shown in Figure 7, the cleaning drum 2 comprises a large number of inlets 58, which are arranged at intervals from one another and with each of which a finger rake 38 is associated, the free end of each finger rake also being lifted clear of the inner wall 8 of the cleaning drum 2. A pneumatic agitating effect for shaking the mixture of crops and impurities is accentuated by the large number of inlets 58 on the cleaning drum 2. The annular channel 54 ends in front of the outlet 10 of the conveying device 14.At the end of the outlet or at the air outlet 60 of the annular channel 54 there can be provided the guide device 42 which can cause the air stream to be deflected.

In a further exemplary embodiment according to Figure 8 the conveying device 14, which is normally provided in the area of the bottom of the cleaning drum 2, is arranged in the area of the top of the cleaning drum. As shown in Figure 8, the pressure connection 6 of the blower 4 lies in the area of the bottom of the cleaning drum 2, the air inlet 56 of the annular channel 54 being approximately diametrically opposite the outlet 10 of the conveying device 14.

According to a further exemplary embodiment as shown in Figure 9, the feeder 18 is mounted coaxially with the cleaning drum 2 and, seen in the conveying direction, is equipped, after the auger conveyor 24, with an additional rotary conveying device 62 which is provided with blades 64. The auger conveyor 24 and the conveying device 62 are mounted on a common shaft 66 which extends through the cleaning drum 2, the conveying device 62 being provided in the cleaning drum 2. This causes the entering mixture of crops and impurities to be also rotated mechanically and moved along the inner wall 8 of the cleaning drum. Therefore a less powerful version of the blower 4 can be used.At the lower end of the cleaning drum 2 there is provided a chopper 68, which can also be in the form of an axial-flow conveyor and which enables the straw to be cut up into small pieces, which are then ejected through the axial opening 70 provided at the rear end of the cleaning drum 2. The opening 70 in this case has a diameter which is approximately equal to the diameter of the cleaning drum 2.

In accordance with the exemplary embodiment shown in Figures 11 and 12 there can be provided, in the front section of the cleaning drum 2, the threshing and separating device 20 which moves past part of the finger rake 38. As a result, the auger conveyor 24 shown in Figure 2 can be omitted. Owing to the coaxial arrangement of the threshing and separating device 20 in the cleaning drum 2, it is possible for the entire threshing and separating device to have a very compact construction. As shown in Figure 11, the threshing and separating device 20 comprises a threshing drum 72 above a concave 74. Owing to the special arrangement of the threshing and separating device 20 in the cleaning drum 2, the separated harvested crops can be fed directly to the cleaning device.

In the exemplary embodiment shown in Figure 13 a suction connection 76, which is connected to a blower 78, is also connected to the rear end of the cleaning drum 2. The blower 78 can be in the form of a radial-flow blower and can be equipped with separate blades 80. The blower 78 is driven via a shaft 82 which can be mounted on the shaft 66. The blower 78 comprises a housing 84 which is equipped with a pressure connection 86 which extends helically around the cleaning drum 2 and is connected to the annular channel 54 (Figure 8).

The air from the cleaning drum 2 is sucked in through the suction connection 76 by this means and is conveyed via the blower 78 into the pressure connection 86 and therefore into the annular channel 54 which passes the cleaning air into the cleaning drum 2 through the inlet 7. A closed system for circulating the cleaning air is obtained in this way. Since the cleaning air is already rotating when it passes out of the cleaning drum 2 into the suction connection 76, it is possible to reduce the power requirement of the cleaning device, as a smaller proportion of acceleration energy must be imparted to the cleaning air. In this device the outlet 88 for impurities is provided at the rear end of the cleaning drum 2 and arranged laterally so that the impurities can also be guided laterally out of the drum, the cleaned harvested crops being discharged through the outlet 10 or 26. Because of this closed system for circulating the cleaning air, the formation of dust is minimised as only a very small proportion of cleaning air can flow in an outward direction out of the cleaning device.

The feeder 18 and the auger conveyor 24 shown in Figure 1 can also be connected at right angles to or tangentially to the pressure connection of the blower 4, as shown in Figure 10, so that the harvested crops pass into the pressure connection 6 through the suction effect of the blower. After the harvested crops enter the pressure connection 6, they are conveyed into the cleaning drum 2 with the cleaning air.

Claims

1. Cleaning device for harvesting machines comprising a cleaning drum, a feeder for feeding threshed material into the drum and a blower for subjected the cleaning drum to cleaning air which is conveyed into the drum through at least one inlet and which separates the harvested crops from impurities, the harvested crops being discharged through at least one sieve-like outlet provided in the cleaning drum, the blower being approximately tangentially connected to the cleaning drum by its pressure connection in such a way that the cleaning air is conveyed, with the harvested crops, along the closed inner wall of the cleaning drum, the cleaned harvested crops being discharged through the outlet(s) which are provided on the wall of and/or at the end of the cleaning drum.

2. Cleaning device according to claim 1, wherein the outlet for the cleaned harvested crops is closed off by a device which generates a dynamic pressure.

3. Cleaning device according to claim 2, wherein the device which generates the dynamic pressure is a conveying device for receiving the cleaned harvested crops.

4. Cleaning device according to claim 1,2 or 3, wherein the outlet, seen in the conveying direction, lies directly behind the inlet of the blower.

5. Cleaning device according to any of the preceding claims, wherein the width of one blower or of a plurality of blowers arranged side by side is approximately equal to the length of the cleaning drum.

6. Cleaning device according to any of the preceding claims, wherein the outlet is divided into sections by means of a separating member through which sections harvested crops, which have been cleaned to varying degrees, are fed to different conveying devices.

7. Cleaning device according to claim 6, wherein the second outlet, which is formed by means of the separating member, is provided, relative to the conveying direction of the harvested crops, in the rear section of the cleaning drum or in an extension of the cleaning drum.

8. Cleaning device according to any of the preceding claims, wherein the end of the feeder for the harvested crops is situated in the front section of the cleaning drum.

9. Cleaning device according to any of the preceding claims, wherein the outlet of the cleaning drum is covered by a device having longitudinal orifices.

10. Cleaning device according to claim 9, wherein the device is in the form of a finger rake, the tines of which form an angle to the plane which extends in the flow direction of the air.

11. Cleaning device according to claim 10, wherein the finger rake is curve-shaped and designed so as to be adjustable.

12. Cleaning device according to claim 10 or 11 , wherein the tines of the finger rakes are spaced from one another by a varying distance.

1 3. Cleaning device according to claim 10, 11 or 12, wherein the finger rake is detachably connected to the cleaning drum.

14. Cleaning device according to any of the preceding claims, wherein a plurality of finger rakes, which are arranged at intervals from one another when seen in the peripheral direction, are provided on the inner wall of the cleaning drum, the rakes being spaced, at their delivery ends, from the inner wall of the cleaning drum.

1 5. Cleaning device according to any of the preceding claims, wherein at least one adjustable guide device is provided in the area of the pressure connection of the cleaning blower

16. Cleaning device according to any of the preceding claims, wherein the device for conveying the cleaned harvested crops comprises, in the area of its inlet connection, an adjustable guide device, the front end of which can be pivoted into the cleaning drum.

1 7. Cleaning device according to any of the preceding claims, wherein at least two blowers, spaced at intervals from one another, or groups of blowers are distributed on the circumference of the cleaning drum.

1 8. Cleaning device according to any of the preceding claims, wherein the cleaning drum comprises a plurality of inlets distributed around the circumference thereof and is at least partially surrounded by an outer, closed jacket which forms an annular channel, the annular channel being connected by its air inlet to the blower(s).

1 9. Cleaning device according to claim 18, wherein a finger rake is associated with each inlet, the finger rake above the outlet being larger than the other finger rakes.

20. Cleaning device according to claim 18, wherein an adjustable guide device is provided on the annular channel in the area of its air outlet.

21. Cleaning device according to any of the preceding claims, wherein the inlet for the cleaning air is provided with the largest inlet cross-section and the outlet for the cleaned harvested crops is provided in the upper section of the cleaning drum.

22. Cleaning device according to one or more of the preceding claims, wherein the feeder for the harvested crops is mounted coaxially with the cleaning drum and is followed by a rotary conveying device which comprises blades and which is mounted concentrically with the feeder.

23. Cleaning device according to any of the preceding claims, wherein the feeder is a threshing and separating device, which extends coaxially with the cleaning drum and runs into the front section of the drum.

24. Cleaning device according to any of claims 1 to 21, wherein the feeder is connected by its outlet connection to the pressure connection of the blower, the outlet connection lying, relative to the conveying direction in the cleaning drum, in a transverse plane which extends through the front part of the cleaning drum.

25. Cleaning device according to any of the preceding claims, wherein a finger rake extends over the entire width of all the outlets for the cleaned harvested crops and at least partially covers the outlets in the conveying direction of the harvested crops.

26. Cleaning device according to any of the preceding claims, wherein the blower is connected, relative to the conveying direction of the harvested crops, to the end of the cleaning drum by a suction connection, the pressure connection of the blower being connected to an annular channel around the drum.

27. Cleaning device according to claim 26, wherein the suction connection of the blower extends coaxially with the cleaning drum.

28. Cleaning device according to any of the preceding claims, wherein an outlet for impurities is provided on the wall of the cleaning drum.