GB2373427A

GB2373427A - Combine harvester separation unit

Info

Publication number: GB2373427A
Application number: GB0106691A
Authority: GB
Inventors: Andrie Visagie; Thomas Barrelmeyer
Original assignee: Claas Selbstfahrende Erntemaschinen GmbH
Current assignee: Claas Selbstfahrende Erntemaschinen GmbH
Priority date: 2001-03-19
Filing date: 2001-03-19
Publication date: 2002-09-25
Also published as: UA76980C2; GB0106691D0; ZA200303742B; WO2002074064A1

Abstract

This invention refers to a combine harvester (2, figure 1) with a rotor housing 22 which is positioned in a lengthwise direction and which comprises a separation rotor 24 inside of the rotor housing 22 and sucking blower means 36 arranged at the discharge end (28, figure 1) of the rotor housing 22. To improve the separation performance of such an axial-flow combine type, it is suggested to arrange a collection chamber 58 in functional proximity towards a deflector plate 54, and transfer elements 62, 64 convey the separated fraction from the collection chamber 58 into an initial portion of the rotor housing 66 so as to allow further separation.

Description

Applicant: Claas Selbstfahrende Erntemaschinen GmbH, Münsterstrasse 33,33428 Harsewinkel, Germany Combine Harvester The present invention relates to a combine harvester with at least one separation unit comprising a rotary driven separation rotor arranged in a rotor housing with a feeding zone where harvested material is fed into the rotor housing, a separation zone with sieve means arranged in the rotor housing of said separation zone, a discharge zone which is located at the discharge end of the rotor housing and a sucking blower unit which sucks an air flow stream at least through the sieve means into the separation zone and the discharge zone, and a grain collecting element arranged in some distance towards the sieve means, all arranged such that a part of the air flow stream is sucked into the separation zone from the space between the sieve means and the grain collecting element, and a deflector plate arranged in said space to deviate said part of air flow stream..

Such a separation unit is known from PCTIUS 97/02432. A deflector plate is suggested to deviate the air flow stream sucked out of the space between the sieve means and the grain collecting element to use the differentiating effect of centrifugal forces and gravity upon the different fractions of kernels and chaff for an improved separation of the different fractions. In the location of the deflector plate a second grain exit is suggested, and from there the separated grain should be guided through a further cleaning process. As a further cleaning element, there may be a conventional cleaning system working with oscillating sieve means, but also a second separation unit comparable in its function with the initial separation unit.

The problem of that cleaning process is, that parts of the kernel fraction to be cleaned might still stick to the ears or other fractions of a plant or dirt, and that the impacts upon such kernels from the cleaning elements are not strong enough to separate such kernels from the elements to be separated. If that fraction of kernels mixed with other elements like straw, ears or chaff is conveyed into the grain tank, the cleaning result of the combine harvester in total would be adversely affected. Accordingly, it is the object of this invention to find a solution how to improve the cleaning function of the separation unit of this type of axial flow combine with a sucking blower unit.

This object can be achieved if a collection chamber is arranged in functional proximity towards a deflector plate, and transfer elements convey the separated fraction from the collection chamber into an initial portion of the rotor housing. In a combine harvester with a one-stage separation unit without further cleaning means such a return mechanism safeguards that especially that fraction of those particles, which have left the rotor housing through the sieve means, but which has not yet been perfectly threshed, is returned into the rotor housing for another threshing cycle and a better cleaning of the sample collected in the grain tank, all achieved on a low level of kernel losses. In the space between the sieve means and the grain collecting element the air flow stream does not lift up the pure and clean kernels because their surface in relation to their weight is too small to be torn away by the wind. So the pure kernels are sliding down the way of the grain collecting element towards the grain collecting auger and from there into the grain tank. Those kernels which still stick to straw, chaff, dirt or ear elements have been heavy enough to exit the rotor housing through the openings in the sieve means, however, their weight in relation to their surface is lighter than that of the pure and clean kernels, and as a result they are blown upwards by the wind. If these kernels are not sorted out of the air flow stream, they would be blown out of the combine harvester and get lost. That an additional separation is possible by a deflector plate has been disclosed in the prior art reference. However, by using the function of the deflector plate to feed back the separated fraction to the rotor housing is a cheap, but very effective solution to improve the cleanliness of the kernel fraction collected in the grain tank without adding expensive and bulky additional functional elements and without risking an increase of losses.

In a combine harvester with a two-stage arrangement of separation units the fraction of harvested good sorted out by the first deflector plate has already been subject of a further cleaning cycle, however, the problem, that there still is a fraction of harvested good containing kernels which stick to straw, dirt, chaff and ears and which need a stronger impact to be separated from such elements than has been effected during the precedent cleaning cycle is still unsolved. Here it brings a big advantage to integrate a second deflector plate in the second separation unit and to return the separated fraction of harvested good into the rotor housing of the first separation unit. So the same advantages described above for a one-stage arrangement also apply for a two-stage arrangement of the separation units.

It is a feature of this invention that the collection chamber comprises of a rear wall, side walls and a floor portion forming a trough-like structure, which guides the separated fraction towards the transfer elements. By such a simple"bucket"which is open towards the deflector plate that fraction of harvested good which has been deviated by the deflector plate can be collected without further driven elements.

It is a further feature of this invention that on the shaft of the separation rotor there is a deflection rotor which kicks fractions of harvested good into the air flow stream generated by a sucking blower unit. By this deflection rotor kernels which might get lost are remitted into the threshing cycle.

It is also suggested to place a closing plate behind the deflection rotor, which comprises an opening in its middle section. Such a closing plates supports the kickout function of the deflection rotor in its periphery, but allows the light chaff fractions to pass it through the central opening.

Further improvements are mentioned as elements of the subclaims. The invention is now described in more detail by virtue of drawings. In the attached drawings the following aspects can be seen: Fig. 1 a side-view upon a self-propelled combine harvester, Fig. 2 a side view upon a single separation unit equipped with the collection chamber and transfer elements to return a fraction of harvested good, Fig. 3 a side view upon a two-stage arrangement of separation units with a collection chamber and transfer elements and further improvements.

A combine harvester 2 shown in figure I is equipped with a driver's cabin 4, an engine 6 with a cooling system 8, a front wheel 10 with a rotational axis 12, a rear wheel 14, a cutter bar 16, and a feeder house 18, which distributes the harvested material from the cutter bar 16 into the feeding opening 20 of the rotor housing 22, which is part of a separation unit. Inside of the rotor housing 22 there is arranged a separation rotor 24, which is rotatably driven by driving elements 26, here shown as pulley drives, from the power of engine 6. Seen along the rotational axis of the separation rotor 24 from the feeding opening 20 towards the discharge end 28 of the rotor housing 22, the front section of the separation rotor 24 comprises auger blades 30 which approximately define the length of the feeding zone where the harvested material is fed into the rotor housing 22. The middle and rearward section of the separation rotor 24 is equipped with beater plates 32 which approximately define the length of the separation zone along the length of the rotor housing 22. It is noted here that the tools for feeding the harvested material into the rotor housing and threshing and separating the harvested material may also be different from auger blades or beater plates, they are mentioned here just as examples. Of course an expert could also choose other tools, which he is aware of and which serve his desired function. The bottom portion of rotor housing 22 comprises of sieve means 34, through which grain kernels and chaff may exit the rotor housing 22. The sucking blower unit 36 sucks an air flow stream at least through the sieve means into the separation zone of the rotor housing 22 and from there towards the discharge zone 28 and out of the rotor housing 22 and out of the combine harvester 2. The sucking blower unit 36 is connected in its function towards the separation rotor 24. Rotor housing 22, separation rotor 24 and sucking blower unit 36 together form the basic components of a separation unit. Grain kernels which exit the rotor housing 22 through the openings of sieve means 34 fall at least partially on the grain collecting element 38 which guides the grain kernels by gravitational forces towards the grain collecting auger 40, which distributes the collected grain into a grain conveyor-not shown-, which feeds the grain into the grain tank 42. The air flow stream generated by the sucking blower 36 is moving through the intermediate space between the sieve means 34 and the grain collecting element 38.

The description above refers to the function of a single separation unit, however, it is to be understood that of course there may be arranged two separation units as described side by side in a combine harvester, and instead of conventional sieve means there may be one or more additional separation units as described in its basic function above for a further cleaning of the separated grain, they should then be arranged underneath the first separation units.

The inclined arrangement of rotor housing 22 and the separation rotor 24, which is arranged inside of rotor housing 22, by more than 300 towards the horizontal plane brings some advantages. First of all, it reduces the speed of the harvested material inside of the rotor housing towards the discharge end 28, so that it rotates inside of the rotor housing 22 along a longer travelling path with more opportunities for separating grain kernels. Due to the fact that the gravitational forces are acting with more effect upon the heavier fractions of the harvested material like the grain kernels, they tend to move slower through the rotor housing 22, which brings some separation effect upon them in relation to the lighter fractions of the harvested material like straw or chaff. An additional advantage is that the grain can be collected by simple grain collecting elements 38, which may be formed in the shape of a chute, and transported towards the collecting auger without any further driven elements. Also for using the second separation rotor 44 as a cleaning apparatus for the fraction of grain kernels and chaff which has exited the rotor housing 22, it is advantageous to have an inclined arrangement of the rotor housing 22, because the air flow stream which is moving along the outer surface of the sieve means 34 towards the sucking blower unit 36 cannot suck the grain kernels upwardly very easily due to their weight, so that they tend to fall either onto the grain collecting element 38 or into the second grain exit towards the second separation rotor 44.

The deflector plate 54 deviates the air flow stream passing the outer surface of sieve means 34, and those fraction of harvested material which are heavier are deviated into the second separation unit.

Also the second separation rotor 44 is combined for its function with a sucking blower unit 74, which generates an air flow stream comparable to the air flow stream generated by the sucking blower unit 36.

The feeder house 18 contains at least two rotation elements, one front rotating element 46 and one rear rotating element 48. The shape of floor 50 of the feeder housing 18 is partially adapted to the circumference of the rotating elements 46,48. In the region where the arrow 20 points to the line which symbolizes the cross wisely arranged cylindrical shape of the feeder house 18 which houses the rear rotating element 48 in the region of its discharge end, there may also be located the feeding opening of the rotor housing 22. The cross wisely arranged cylindrical shape of the feeder house 18 cuts into the upper half of the length wisely arranged substantially cylindrical shape of the rotor housing 22. The rotating energy of the separation rotor 24,44 can be transmitted to subordinated elements, which is symbolized by arrow 52.

If the rotor housing 22 is arranged in the combine harvester 2 as described, it is possible to position the engine 6 in a location also in the top rear half portion of the combine harvester 2 behind the rear end of the rotor housing 22. This is advantageous because the power of the engine doesn't need to be transported over long distances towards the separation rotor 24, which saves costs and weight. The high arrangement of the engine also avoids that the cooling system sucks in too many straw which is blown out in a downward and rearward direction by the sucking blower means 36 and the blower of the second separation unit. The power necessary to drive the cutter bar 16 and the feeding elements 46,48 arranged inside of the feeder house 18 or other working components or generators of hydraulic pressure or electrical energy may be transmitted by the shaft of separation rotor 24 or 44 from the rear to the front of the combine harvester 2. This saves additional drive train elements and it keeps the width of the combine harvester 2 slim. The PTO stubble shaft of the separation rotors 24,44 may be equipped with toothed wheels which transfer the rotating energy to subordinated shafts, hydraulic pumps, electric generators, gearboxes or the like. For the sake of simplified demonstration, the possibility of driving any other components is indicated by arrow 52.

In the triangle defined by the upper half of the rotor housing 22, the rear wall of the cabin 4 and the top margin of the combine harvester 2, it is easy to accommodate the grain tank 42. If there is only one separation rotor contained in the rotor housing (two in a side-by-side arrangement are possible), the space of the grain tank 42 may even reach downwardly along the sides of rotor housing 22 so that it is designed like a saddle tank.

To achieve enough space to place the front end of rotor housing 22 as low as possible, it is advantageous to avoid a rigid front axle or a cross wisely arranged beam of the machine frame in the region proximate to the front wheel. To drive the front wheels, small hydraulic or electric motors can be placed next to each wheel so that one motor drives one wheel.

Whereas figure 1 has been used to explain the general function of a sucking blower unit-type axial flow combine, now the basic idea of the invention is explained in more detail in figure 2.

At the deflector plate 54 the travelling path of the air flow stream is deviated. The traveling path of the deviated air flow stream is symbolized by the arrow W. The higher the suspension velocity of those particles transported by the air flow stream is, the more slowly they tend to change their travelling direction.

So if the wind blows around the deflector plate 54, some of the particles transported by the air flow stream do not change their traveling direction fast enough, and they bump against the deflector plate 54. Being stopped and out of the wind, the only force which acts upon them is the gravitational force, and accordingly these particles tend to fall down in a vertical line. As soon as they reach the air flow stream, it will of course have an impact upon the traveling path, however, these particles only get slowly accelerated by the air flow stream again, and

there is only a slight change of the travelling direction. Their traveling path is indicated by arrow Kl.

Other particles transported by the air flow stream are moved in a more downward direction by the deviation of the air flow stream and they succeed not to collide with deflector plate 54, however, the air flow stream is not strong enough to lift the traveling path of these particles up and back again towards arrow W. As a result, these particles bump against the rear wall 56 of the collection chamber 58 and fall down on the floor 60 of collection chamber 58. With the term"in functional proximity"as an indication, where the collection chamber 58 is positioned, is meant that the collection chamber 58 should be placed at a location where at least a good amount of the deviated particles, those which collided with the deflector plate 54 and those which bumped against the rear wall 56, fall down on the floor 60 of collection chamber 58. The best position is a bit towards the rear, with the rear wall 56 extending at least up to the height of the location of deflector plate 54. By a slight inclination of the floor 60 of the collection chamber 58, the collected fraction slides due to gravitational forces towards the transfer element, comprising in this example of an auger 62 to feed the collected fraction sidewards, and a conveyor 64, which feeds the collected fraction back to the front, where it enters the rotor housing 22 at gate 66. Instead of the conveyor shown in figure 2 as an example, also other components covering the same function, for example hoses through which the collected fraction is blown through by a blower unit, are possible.

In figure 3 there is a deflector plate 54 added to the second separation unit with separation rotor 44, and the collecting chamber 58 is arranged in functional proximity to the deflector plate 54 again. On the shaft of separation rotor 44 there are fixed the blades of a deflection rotor 68. Deflection rotor 68 is intended to kick out all heavier particles out of the flow of harvested good which is sucked upwards along the sieve means 34 under the separation rotor 44. The lighter fraction like chaff is sucked through the central opening in closing plate 70 into the direction of sucking blower unit 72. The sucking blower unit 74 is fixed on hollow shaft 76 which is concentrically mounted on the shaft of separation rotor 44 and driven by the disc 78. Sucking blower unit 74 with its hollow shaft 76 may thereby be operated with higher rotational speeds than separation rotor 44. To kick out even those remaining kernels which might have been sucked through the central opening in closing plate 70 further deflection plates 80 are arranged between the closing plate 70 and the sucking blower unit 74. To avoid kernel breakage, these deflection plates are fixed on the shaft of the separation rotor 44, which is running potentially with lower speeds than the sucking blower unit 74. The deflection rotor 68 and the deflection plates 80 kick the kernels cross wisely through the air flow stream, which is generated by sucking blower unit 74, against the rear wall of the collection chamber 58. Other than shown in figure 3, the deflection plates 80 may also be fixed on hollow shaft 76 as an alternative, if the deflecting function of the deflection rotor 68 is already sufficient and a higher separation performance is requested due to the higher rotational speed of deflection plates 80, if they are fixed on hollow shaft 76. With such an arrangement losses of kernels can be avoided to a great extent. All the elements described before may also be used in a single separation unit either respectively.

The examples shown in the figures and explained above are not meant to be limited towards the embodiments shown. Of course it is possible for an expert to adapt the concept described towards the requirements of his application, and functional elements of one example may be integrated into the concept from another example. Also the dimensions and diameters are meant for illustration purposes only and may be adapted to the requirements of a certain application.

Claims

1. Combine harvester with at least one separation unit comprising a rotary driven separation rotor arranged in a rotor housing with a feeding zone where harvested material is fed into the rotor housing, a separation zone with sieve means arranged in the rotor housing of said separation zone, a discharge zone which is located at the discharge end of the rotor housing and a sucking blower unit which sucks an air flow stream at least through the sieve means into the separation zone and the discharge zone, and a grain collecting element arranged in some distance towards the sieve means, all arranged such that a part of the air flow stream is sucked into the separation zone from the space between the sieve means and the grain collecting element, and a deflector plate arranged in said space to deviate said part of air flow stream, characterized in, that a collection chamber (58) is arranged in functional proximity towards a deflector plate (54), and transfer elements (62,64) convey the separated fraction from the collection chamber (58) into an initial portion of the rotor housing (22).

2. Combine harvester according to claim 1, characterized in, that the collection chamber (58) comprises of a rear wall (56), side walls and a floor portion (60) forming a trough-like structure which guides the separated fraction towards the transfer elements (62,64).

3. Combine harvester according to claim 1 or 2, characterized in, that on the shaft of the separation rotor (24,44) there is a deflection rotor (68) which kicks fractions of harvested good into the air flow stream generated by a sucking blower unit (36,74).

4. Combine harvester according to claim 3, characterized in, that a closing plate (70) with an opening in its middle section is placed behind the deflection rotor (68).

5. Combine harvester according to claim 3 or 4, characterized in, that additional deflection plates (80) are placed behind the deflection rotor (68).

6. Combine harvester according to one or more of the preceding claims 3 to 5, characterized in, that the deflection rotor (68) and/or the deflection plates (80) kick fractions of harvested good into the air flow stream generated by the sucking blower unit (36, 74).

7. Combine harvester according to one or more of the preceding claims, characterized in, that the sucking blower unit (74) is operable with a higher rotational speed than the deflection rotor (68) and/or the deflection plates (80).