Patent Description:
As is described in <CIT>, a cleaning system for a combine harvester includes a fan assembly that is configured to blow air through reciprocating sieves to carry lighter elements of material other than grain (MOG) or chaff away.

Transverse or cross-flow fans of various designs have been advantageously employed with agricultural combines to provide the air that is blown upwardly and rearwardly through the sieves to carry the chaff away from the grain and tailings deposited onto the cleaning system sieves. Transverse fans are useful in combine cleaning systems because such fans can produce a wide stream of air that can be directed upwardly toward the cleaning sieves of the combine cleaning systems but require relatively little space. Such fans, in typical agricultural combines, are disposed such that their air outlet ports are below the sieves of the cleaning system.

One problem with transverse fans is that the air blowing through the fan housing will receive air through its inlet in a uniform manner, however, the air can be unevenly distributed through the outlet ports of the fan. This problem may occur during the process of loading and unloading the sieves. The air within the fan housing will typically follow the path of least resistance, namely, toward the unobstructed portion of the sieves. This may be referred to in the art as a blowout condition.

<CIT> discloses a combine harvester including a cutting and conveyance device for crop, a threshing device for separating grain from the crop, a sieve system arranged in the longitudinal direction of the combine harvester, and a blower system comprising at least two blowers disposed upstream of the sieve system transversely to the longitudinal direction of the combine harvester and controlled independently of one another.

It would be desirable to provide uniform distribution of air through the outlet ports of the fan assembly in order to improve cleaning efficiency, crop processing, and either limit or prevent a blowout condition. It would also be desirable to achieve the aforementioned uniform distribution of air in an automated manner.

The disclosure is generally directed to a cleaning system of a combine harvester.

According to the invention, a cleaning system of a combine harvester comprises:.

Preferably, each sensor is a pressure transducer, a pressure switch, or a strain gauge.

According to an aspect of the invention, a combine harvester comprising the cleaning system is provided. Preferably, the combine harvester further comprises a rotor and concave that are positioned at an elevation above the cleaning system.

According to another aspect of the invention, a method for operating a cleaning system comprises:.

Preferably, the first sensor is mounted to a housing for the first sieve, and the second sensor is mounted to a housing for the second sieve.

The first sensor may at least partially be positioned within the first duct, and the second sensor may at least partially be positioned within the second duct.

Preferably, each valve member is pivotally connected to the fan housing.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates an embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.

It should be appreciated that, while the following discussion will be directed principally to cleaning system embodiments as employed in such a combine harvester, the cleaning systems of the present invention are not limited to use in such harvesters, but could equally as well be employed or utilized in or with other harvesters and equipment, or with other equipment or in other circumstances and situations, consistent with the principles and teachings expounded.

For convenience of reference and understanding in the following discussions, and with respect to the various drawings and their descriptions, the point of reference for the use of various terms that are hereafter employed, including "left", "right", "forward", "rearward", "front", "back", "top", and "bottom", should generally be considered to be taken from a point at the rear of the machine facing in its normal direction of travel, unless it is clear from the discussion and context that a different point of reference is appropriate. Any use of such terms should therefore be considered exemplary and should not be construed as limiting or introducing limitations.

Moreover, inasmuch as various components and features of harvesters and fan assemblies are of well-known design, construction, and operation to those skilled in the art, the details of such components and their operations will not generally be discussed in significant detail unless considered of pertinence to the present invention or desirable for purposes of better understanding.

<FIG> and <FIG>, which are reproduced from <CIT>, identify the general location of and depict a conventional transverse fan assembly <NUM> arranged in operable combination with a typical, conventional, self-propelled agricultural combine harvester <NUM> of the axial-flow type wherein crop material is threshed and separated while it is advanced by and along a generally longitudinally arranged rotor.

As is well known in the art, and as is better illustrated in <FIG>, a threshing apparatus <NUM> of the combine harvester <NUM> includes a rotor assembly <NUM>, including a relatively large diameter rotor <NUM> that is mounted within a threshing cage <NUM>. Disposed about the cage <NUM> is a system of concaves <NUM> and separating grates <NUM> which, through the action of the rotor <NUM> and centrifugal force, act to separate grain material from other crop residue that is too large to pass through the concaves <NUM> and grates <NUM>, sometimes hereafter referred to as straw.

The threshed grain material is delivered to a cleaning system <NUM> that includes a pair of vertically spaced apart cleaning sieves <NUM> and <NUM> while the straw is propelled rearwardly through the rotor assembly <NUM> where a conventional beater <NUM> acts upon the crop residue discharged from the rotor assembly <NUM>. Beater <NUM> propels the crop residue from the rear of the rotor assembly <NUM> and throws it back for broad discharge from the rear end of the combine.

As may be observed from <FIG>, an auger <NUM> moves the threshed grain material to the cleaning sieves <NUM> and <NUM>, which sieves form part of the cleaning system <NUM> and are mounted for oscillation to separate grain from other larger pieces of threshed crop material. As the sieves <NUM> and <NUM> are vibrated or oscillated, the grain falls through the sieves <NUM> and <NUM> to an underlying clean grain pan <NUM> and into a clean grain trough or collector <NUM>. An auger <NUM> directs the grain from the clean grain trough <NUM> into a hopper or grain bin (not shown) often housed generally directly behind the cab <NUM> (<FIG>) within combine harvester body <NUM>.

The threshed grain material that is too large to fall through the sieves <NUM> and <NUM> forms a relatively large crop mat or veil extending across substantially the entire sieve construction, as fan assembly <NUM> provides air that is blown upwardly and rearwardly, as denoted by the arrows, through sieves <NUM> and <NUM>. Such air flow acts to blow lighter, non-grain elements, sometimes referred to as chaff, away from the crop mat remaining on the sieves <NUM> and <NUM> towards the rear of the harvester, where such chaff is handled in conventional and well-known manners.

The fan assembly <NUM> shown in <FIG> includes a single outlet port directed to sieves <NUM> and <NUM>, however, other fan assemblies include multiple outlet ports, such as the fan shown in <FIG>. For example, a first outlet port is positioned to direct air to a first sieve (commonly referred to as a "pre-sieve"), and a second outlet port is positioned to direct air to one or more additional sieves (e.g., chaffer sieves). As is described above, in fan assemblies having multiple outlet ports, one problem is that air can be unevenly distributed through the outlet ports during the loading and unloading processes.

Turning now to <FIG>, there is illustrated a cleaning system <NUM> for a combine harvester, in accordance with an exemplary embodiment. Cleaning system <NUM> may be used with the combine of <FIG> or a different combine. The cleaning system <NUM> comprises a transverse fan assembly <NUM> and a cleaning shoe <NUM>. The cleaning shoe comprises, at least in part, sieves 309a-309c. The fan assembly <NUM> may replace the fan assembly <NUM> of <FIG> and <FIG> in the combine harvester. And, the sieves 309a-309c may replace the sieves <NUM> and <NUM>.

The fan assembly <NUM> includes a housing <NUM> having a series of panels that are mounted together to form an interconnected housing. The fan assembly <NUM> includes an air inlet <NUM> at its top end. Unlike the fan assembly <NUM> of <FIG>, the fan assembly <NUM> includes two exhaust or outlet openings <NUM> and <NUM> through which air is exhausted. Behind the front panel <NUM> is disposed a curved divider <NUM> positioned between the exhaust openings <NUM> and <NUM>. The curved divider <NUM> serves to separate the inlet air flow <NUM> into two different exhaust flow streams, namely, exhaust air flow <NUM> and exhaust air flow <NUM>.

The fan assembly <NUM> includes a single, unitary rotor <NUM>. The rotor <NUM> includes a series of blades <NUM> for drawing air through the housing <NUM> from the inlet <NUM> to the outlets openings <NUM> and <NUM>. The rotor <NUM> may be driven by a single drive.

A first valve member 320a is positioned within the duct <NUM> leading to the first outlet opening <NUM>. First valve member 320a is pivotably connected to the divider <NUM> by a pivot point <NUM>, bearing or hinge. The location of first valve member 320a within the duct <NUM> may vary, and, the location of the pivot point <NUM> may also vary. Valve member 320a may extend to a length that is either equal to the space in the duct <NUM> (as shown), or less than that space.

Although not shown in <FIG>, an actuator 402a is configured to rotate the first valve member 320a about pivot point <NUM> and within the duct <NUM> (see arrows) based upon instructions received from a controller <NUM>. Actuator 402a may be actuated either electrically or hydraulically, for example. Actuator 402a could be a solenoid, gear motor, or hydraulic piston, for example.

First valve member 320a is configured to be moved between a fully-closed position (not shown) and a fully open position (shown) by actuator 402a. In the fully-closed position, the first valve member 320a is rotated to a position such that it prevents the air flow <NUM> from being expelled through the outlet opening <NUM>. In a fully-open position, the first valve member 320a is rotated to a position such that it does not prevent the air flow <NUM> from being expelled through the outlet opening <NUM>. In operation, the first valve member 320a may be rotated to any predetermined position that is defined between the fully-open and fully-closed positions.

Similarly, a second valve member 320b is positioned within the duct <NUM> leading to the second outlet opening <NUM>. Although not shown in <FIG>, an actuator 402b is configured to rotate the second valve member 320b within the duct <NUM> (see arrows) based upon instructions received from controller <NUM>. Valve member 320b and actuator 402b share the same structure and function as the valve member 320a and actuator 402a, and will not be described further.

Cleaning shoe <NUM> comprises a shoe housing <NUM> (only a portion of which is shown) to which the sieves 309a-309c are connected. The function of a cleaning shoe is well understood in the art. Located beneath each sieve 309a-309c is a pressure sensor 352a-352c, respectively. Each pressure sensor 352a-352c may be mounted directly to shoe housing <NUM>. Each pressure sensor 352a-352c is configured to sense the air pressure being delivered by the fan <NUM> onto the respective sieves 309a-309c, respectively, via the outlet openings <NUM>/<NUM>. Sensors 352a-352c transmit the air pressure readings to controller <NUM>.

A second set of pressure sensors 360a and 360b are positioned within the ducts <NUM> and <NUM>, respectively. Pressure sensors 360a and 360b sense the air pressure being delivered through the ducts <NUM> and <NUM>, respectively. Pressure sensors 360a and 360b also sense any backpressure caused by loading of the sieves <NUM>, which is communicated via ducts <NUM> and <NUM>, respectively. Thus, for example, pressure sensor 352a can sense backpressure caused by crop loading at sieve 309a. And, pressure sensor 352a senses an air pressure that is indicative of the air pressure at sieve 309a. It can also be stated that air pressure sensor 352a is 'near' sieve 309a because it is positioned within the air duct that faces the sieve 309a.

Pressure sensors <NUM> and <NUM> may be any conventional, off-the-shelf, pressure transducer, pressure switch, or strain gauge, for example. Other styles of pressure sensors are known to those skilled in the art.

According to the embodiment shown, system <NUM> includes pressure sensors <NUM> and pressure sensors <NUM>. According to another embodiment, system <NUM> includes pressure sensors <NUM>, but not pressure sensors <NUM>. According to yet another embodiment, system <NUM> includes pressure sensors <NUM>, but not pressure sensors <NUM>. Sensors <NUM> may be provided on a conventional cleaning system to serve other purposes such as monitoring the air pressure in the sieves, whereby the monitored air pressures are used for adjusting the sieve opening and fan speed based upon the monitored air pressure. Thus, cleaning system <NUM> may take advantage of existing sensors in a combine harvester.

<FIG> depicts a schematic diagram of a system <NUM> for controlling air flow in the cleaning system <NUM>. As noted above, cleaning system <NUM> can include sensors <NUM> and/or sensors <NUM>. Controller <NUM> receives pressure readings transmitted from sensors <NUM> and/or sensors <NUM>. Controller <NUM> analyzes the pressure readings to determine the pressure level at the ducts <NUM> and <NUM> and/or the sieves <NUM> and identifies any imbalance in pressures between the ducts <NUM> and <NUM> and at the sieves <NUM>. The controller <NUM> can include a memory having a table of valve positions related to desired air pressure values. Based upon the pressure readings transmitted from sensors <NUM> and/or sensors <NUM>, the controller <NUM> activates the actuators 402a and/or 402b to adjust the rotational positions of the valves 320a and 320b between their open and closed positions, respectively, thereby affecting the air flow at the sieves <NUM>. Communications between controller <NUM> and sensors and actuators may be either wired or wireless.

For example, sensor 352a may measure a higher air pressure than pressure sensors 352b and 352c indicating that the air pressure at sieve 309a is higher than the air pressure at sieves 309b and 309c. Accordingly, based upon the measured pressures, the controller <NUM> would either (i) move valve 320a closer toward its closed position (by way of actuator 402a), or (ii) move valve 320b closer toward its open position (by way of actuator 402b), in order to increase the air flow to sieves 309b and 309c. Controller <NUM> may be configured to (i) maintain equal air pressure at the sieves, (ii) maintain the air pressure at each sieve at a pre-defined pressure, or (iii) maintain the air pressure at the sieves at a pre-defined differential (e.g., <NUM>% air flow to sieve 309a, and <NUM>% air flow to sieves 309b and 309c).

<FIG> depicts a flow chart showing an exemplary closed loop method or routine <NUM> for operating the cleaning system of <FIG>. According to routine <NUM>, at step <NUM>, sensors <NUM> and/or <NUM> transmit the local air pressures to controller <NUM>. At step <NUM>, controller <NUM> determines the air pressure at each sieve <NUM> (either directly via sensors <NUM> or indirectly via sensors <NUM>), and then calculates a deviance (i.e., an error) from a desired air pressure at each sieve <NUM> using an algorithm. At step <NUM>, and if required due to the occurrence of a deviance, the controller <NUM> transmits instructions (in the form of an error signal) to actuators <NUM> in order to change the position of one or more valves <NUM> within their ducts, in an effort to maintain the air pressure at the sieves at the desired air pressures. The routine <NUM> then returns to step <NUM> to monitor the local air pressures that were adjusted at step <NUM>, and proceeds to adjust the valves <NUM> again at step <NUM> , if necessary. The controller <NUM> may utilize a proportional-integral-derivative (PID) loop to eventually reach the desired air pressure at each sieve <NUM>. It should be understood that system <NUM> is a closed loop system.

It is to be understood that the operational steps are performed by the controller <NUM> upon loading and executing software code or instructions which are tangibly stored on a tangible computer readable medium, such as on a magnetic medium, e.g., a computer hard drive, an optical medium, e.g., an optical disc, solid-state memory, e.g., flash memory, or other storage media known in the art. Thus, any of the functionality performed by the controller <NUM> described herein is implemented in software code or instructions which are tangibly stored on a tangible computer readable medium. Upon loading and executing such software code or instructions by the controller <NUM>, the controller may perform any of the functionality of the controller described herein, including any steps of the methods described herein.

The term "software code" or "code" used herein refers to any instructions or set of instructions that influence the operation of a computer or controller <NUM>.

Claim 1:
A cleaning system (<NUM>) of a combine harvester (<NUM>) comprising a fan assembly (<NUM>) comprising a housing (<NUM>), a fan rotor (<NUM>) at least partially positioned within the housing, and at least one inlet duct (<NUM>) through which air is delivered into the housing, the cleaning system further comprising:
a first duct (<NUM>) leading to a first outlet port (<NUM>) through which air is exhausted outside of the housing, and a second duct (<NUM>) leading to a second outlet port (<NUM>) through which air is also exhausted outside of the housing,
a first valve member (320a) positioned within the first duct for throttling the flow of air through the first duct;
a second valve member (320b) positioned within the second duct for throttling the flow of air through the second duct;
a first actuator (402a) for adjusting a position of the first valve member within the first duct;
a second actuator (402b) for adjusting a position of the second valve member within the second duct;
a first sieve (309a) positioned adjacent the first outlet port to receive a flow of air from the first duct;
a second sieve (309b/309c) positioned adjacent the second outlet port to receive a flow of air from the second duct;
a first sensor (352a/360a) for either directly or indirectly sensing an air pressure at the first sieve;
a second sensor (352b/352c/360b) for either directly or indirectly sensing an air pressure at the second sieve; and
a controller (<NUM>) configured to receive the sensed air pressures from the first and second sensors, compare the sensed air pressures with either each other or threshold values, and transmit instructions to one or both of the first and second actuators to adjust the positions of one or both of the first and second valve members based upon the comparison and thereby adjust the flow of air to the first and/or second sieves,
characterized in that each valve member (320a, 320b) is pivotable connected to the housing of the fan assembly.