Patent Description:
As is described in <CIT> (the '<NUM> Patent), combine grain tank unloading systems of combine harvesters typically consist of single or multiple apparatus including a cross conveyor or conveyors, that feed grain to an unloader conveyor or conveyors, and a vertical unloader conveyor, such as an auger, operable for lifting the grain to a generally horizontal conveyor or auger that conveys the grain to a truck or other holding bin.

A further agricultural vehicle with a conveyor and a clutch is known from <CIT>. Further viscous clutches are e.g. known from <CIT>, <CIT> and <CIT>.

It would be desirable to have a capability to control the unload rate of an unloader conveyor, for instance, to more accurately meter grain to top off trucks or other receptacles, and to fill smaller wagons and receptacles.

In view of the foregoing Background, disclosed herein is a viscous clutch for use with combine grain tank unloading systems of combine harvesters. It should be understood, however, that the viscous clutch is not limited for use with unloading systems, rather, the viscous clutch is applicable for use with any variable speed (non-zero control) mechanical power transmission system, such as those systems in a combine harvester.

The invention is related to an agricultural vehicle, in particular a combine harvester, in accordance with the appended claims. The vehicle comprises an apparatus for feeding or conveying grain comprises a conveyor for moving grain having an input end and an output end; and a viscous clutch either directly or indirectly connected to the input end of the conveyor for transmitting torque from an input component to the conveyor in a variable manner.

The invention is furthermore related to methods as described in the appended claims, of feeding or conveying grain using a conveyor in an agricultural vehicle, said methods comprising: operating a viscous clutch, which is either directly or indirectly connected to an input end of the conveyor, to transmit torque from an input component to the conveyor in a variable manner.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates an embodiment of the invention, in one form.

Inasmuch as various components and features of harvesters 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.

In the drawings, like numerals refer to like items, certain elements and features may be labeled or marked on a representative basis without each like element or feature necessarily being individually shown, labeled, or marked, and certain elements are labeled and marked in only some, but not all, of the drawing figures.

Referring now the drawings, in <FIG>, a representative agricultural harvesting machine <NUM> is shown, including an unloader conveyor <NUM> operable for unloading grain from a grain holding device, which is a conventional grain tank <NUM>, located on an upper region of harvesting machine <NUM>. Such a machine <NUM> is described in the '<NUM> Patent. Here, harvesting machine <NUM> is depicted as a well-known, commercially available combine operable for harvesting a wide variety of grains, including, but not limited to, wheat, beans, corn, rice, and the like. Typically, the grain is harvested and threshed from stalks, pods, or other crop material, and conveyed away from a cleaning system of machine <NUM> by a clean grain conveyor to a grain elevator (not shown). The grain elevator then lifts the grain upwardly to a grain delivery conveyor which is operable for discharging the grain into grain tank <NUM>. When grain tank <NUM> is filled with grain, or filled to a desired level, unloader conveyor <NUM> can be operated for unloading the grain from tank <NUM>, onto the ground, or into a wagon, truck or other vehicle, or a bin or other grain receptacle <NUM> (larger receptacle illustrated for example) or 16A (smaller receptacle).

Referring also to <FIG> and <FIG>, grain tank <NUM> includes apparatus <NUM> operable for feeding or conveying the grain contained therein to unloader conveyor <NUM>. Here, apparatus <NUM> includes a pair of conventional cross conveyors <NUM> and <NUM> disposed in sideward extending covered troughs <NUM> in a floor of the grain tank, in the well-known manner. Cross conveyors <NUM> and <NUM> each comprises a generally horizontal elongate helical auger rotatable by a drive <NUM> (via a clutch <NUM>) as denoted by the arrows in <FIG>, for conveying grain through the respective troughs <NUM> to an opening <NUM> in an inlet end <NUM> of unloader conveyor <NUM>. Each conveyor has an input end 20a and an opposite output end 20b. Here also, it should be noted that although apparatus <NUM> in grain tank <NUM> is illustrated including two cross conveyors <NUM> and <NUM> for feeding grain to unloader conveyor <NUM>, a variety of other conveyor configurations can be utilized for performing this function, including, but not limited to, a single conveyor, or more than two conveyors, such as two cross conveyors that feed to a main conveyor, which, in turn, feeds the unloader conveyor. Also, although helical augers are shown, apparatus <NUM> can comprise other type conveyors, such as a moving belt or belts, or any other apparatus suitable for feeding grain to the unloader conveyor.

Unloader conveyor <NUM> here includes an elongate upwardly or generally vertically extending auger <NUM> supported for rotation in an upwardly extending tubular housing <NUM>, and an elongate auger <NUM> oriented horizontally or at a small acute angle to horizontal, supported for rotation in an elongate tubular housing <NUM> connected to and forming a continuation of housing <NUM>. Housing <NUM> and an upper portion of housing <NUM> are supported in cantilever relation by a lower portion of housing <NUM> for rotation relative thereto, between a sidewardly extending unloading position as shown in <FIG>, and a rearwardly extending stowed position at about a <NUM> degree angle to the unloading position, in the well-known manner. Auger <NUM> is connected to auger <NUM> for rotation thereby in a suitable manner, such as by bevel gears, a Hooke's joint, or the like, also in the well-known manner. Auger <NUM> is driven by the drive <NUM> connected thereto.

A drive <NUM> is connected to conveyors <NUM>, <NUM> and <NUM> for rotating conveyors in the desired rotational direction. Drive <NUM> may represent an engine, a motor, an electric drive motor, a fluid motor, or a driven shaft that is connected to the motor of the machine <NUM>, for example. Although only one drive <NUM> is shown connected to conveyors <NUM>, <NUM> and <NUM>, it should be understood that machine <NUM> may include multiple independent drives <NUM> for independently driving conveyors <NUM>, <NUM> and <NUM>.

Drive <NUM> is connected to each of conveyors <NUM>, <NUM> and <NUM> via an input component 32a, a viscous clutch <NUM> and an output component 32b. Input component 32a and output component 32b may each be a shaft (such as a PTO shaft), a belt, or a chain, one or more gears, a gear box or a transmission that provides a two-stage reduction in power (for example) for driving the conveyors <NUM>, <NUM> and <NUM> at an appropriate speed.

A separate clutch <NUM> is associated with each conveyor <NUM>, <NUM> and <NUM>. Alternatively, and although not shown in <FIG>, the output of a single clutch <NUM> may be connected to all of the conveyors <NUM>, <NUM> and <NUM> (or output components 32b) by way of one or more belts, shafts, etc. for simultaneously controlling all of those conveyors <NUM>, <NUM> and <NUM>. Viscous clutch <NUM> accomplishes variable speed control for each conveyor <NUM>, <NUM>, <NUM> regardless of the speed transmitted by the input component 32a. Each clutch <NUM> is shown connected to the output side of the input component 32a and the input side of the output component 32b. The output side of the output component 32b is either directly or indirectly connected to one of the conveyors <NUM>, <NUM> and <NUM>. As an alternative to the embodiment shown in <FIG>, each clutch <NUM> may be connected directly between drive <NUM> and one of the conveyors <NUM>, <NUM>, <NUM>.

Machine <NUM> further comprises a control <NUM> that is operable for controlling unloader conveyor <NUM> and apparatus <NUM>. Elements of control <NUM> include a processor based controller <NUM> that is connected to an input device <NUM>, drive <NUM> and clutches <NUM> by suitable conductive paths <NUM>. Paths <NUM> can be, for instance, wires of a wiring harness, or a wired or wireless communications network. To facilitate convenient and simple operation, input device <NUM> can be located on a multi-function or propulsion handle <NUM> (<FIG>) or other location on the machine <NUM>.

Turning now to <FIG>, each clutch <NUM> is an electromagnetically actuated viscous clutch. The details of such an exemplary clutch for use with machine <NUM> are described in <CIT>.

The clutch <NUM> permits selective engagement between input component 32a (connected to drive <NUM>) and output component 32b (connected to one of the conveyors <NUM>, <NUM>, <NUM>), for example, to selectively drive one of the conveyors <NUM>, <NUM>, <NUM> as a function of a rotational input from the input component 32a. In a closed position of the clutch, rotation of the input component 32a is transmitted to the output component 32b, whereas, in an open position of the clutch, rotation of the input component 32a is not transmitted to the output component 32b. It is noted that clutch may not, necessarily, achieve full decoupling. Controller <NUM> is connected to clutches <NUM> for selectively varying (i.e., metering) the torque transmission between the input component 32a and the output component 32b.

Referring now to the details of the clutch <NUM>, clutch <NUM> includes a rotor <NUM> and a housing <NUM> (having a front part 102a and a rear part 102B) that generally surrounds the rotor <NUM> to define a working chamber <NUM> therebetween. The input component 32a, is fixedly connected to the front part 102a of the housing <NUM> by one or more bolts (for example). An electromagnetically controlled valve assembly <NUM> regulates the flow of shear fluid (e.g., a conventional silicon oil shear fluid) from a fluid reservoir <NUM> through a return bore <NUM> to control clutch engagement. An opening 126A is formed between front and rear sides of the rotor <NUM>, and a channel <NUM> is formed in the rotor <NUM> between the opening 126A and an area adjacent to the return bore <NUM>. The valve assembly <NUM> is configured to selectively permit shear fluid to pass out of the return bore <NUM>, through the channel <NUM>, and then to the working chamber <NUM>. In this way, shear fluid can be delivered to the working chamber <NUM> at both the front and rear sides of the rotor <NUM> approximately simultaneously, and the working chamber can essentially fill from an outer diameter toward and inner diameter.

The cover plate <NUM> of the valve assembly <NUM> is designed such that it is biased to uncover the opening <NUM> in the rear plate 112A of the reservoir <NUM> (i.e., an "on" or open position where the clutch <NUM> is engaged) by default, which permits shear fluid to flow from the reservoir <NUM> to the working chamber <NUM>. This position of plate <NUM> is not shown. Shear fluid present in the working chamber <NUM> transmits torque by creating a frictional engagement between the rotor <NUM> and the housing <NUM>, and the instantaneous percentage of torque transmission can vary as a function of the amount of shear fluid in the working chamber <NUM>.

The valve assembly <NUM> can be electromagnetically actuated to close the opening <NUM> (as shown in <FIG>). When the electromagnetic coil assembly <NUM> is energized (as controlled by controller <NUM>), magnetic flux is generated by the coil <NUM> and is transmitted through the flux circuit to move the armature <NUM> toward the pole plate <NUM>, which in turn moves the cover plate <NUM> toward the opening <NUM> in the rear plate 112A of the reservoir <NUM>. In this way, energizing the coil assembly <NUM> causes the clutch <NUM> to disengage by covering the opening <NUM> more, which limits or prevents shear fluid from passing from the reservoir <NUM> to the working chamber <NUM> (as shown).

As an alternative to the arrangement described above, cover plate <NUM> may be normally biased to cover the opening <NUM>, and valve assembly <NUM> can be actuated to uncover the opening <NUM>.

The radial channel <NUM> is formed in the front side of the rotor <NUM>, relative to the location of the cover plate <NUM> and the opening in the rear plate 112A of the reservoir <NUM>. The radial channel <NUM> provides space for the cover plate <NUM> to move axially to cover and uncover the opening <NUM> in the rear plate 112A of the reservoir <NUM>. In addition, the radial channel <NUM> and the groove <NUM> together form a fluid path between the opening <NUM> from the reservoir <NUM> to the opening 126A near the outer diameter (OD) of the rotor <NUM>. In that way, input of shear fluid to the working chamber <NUM> occurs at one of the fluid openings (e.g., fluid opening 126A), which provides a fluid outlet that is substantially centered axially in the rotor and is substantially radially centered. Locating the fluid outlet at or near the axial center of the rotor <NUM> permits feeding shear fluid to the working chamber <NUM> at both the front and rear sides of the rotor substantially simultaneously, as well as permitting feeding the shear fluid to the working chamber <NUM> near the OD of the rotor <NUM>.

During operation, the fluid pump system that includes a fluid return path (not shown) pumps shear fluid from the working chamber <NUM> back to the reservoir <NUM>. Shear fluid is essentially continuously pumped back from the working chamber <NUM> to the reservoir <NUM>. The clutch <NUM> remains engaged only by continuing to keep the valve assembly <NUM> in an open position, allowing more shear fluid to move (i.e., return) from the reservoir <NUM> to the working chamber <NUM>. Conversely, the working chamber <NUM> can be effectively drained by moving the valve assembly <NUM> to a fully closed position, and preventing shear fluid from returning to the working chamber <NUM>.

The degree of energization of electromagnetic coil assembly <NUM>, which affects the amount of shear fluid in the working chamber <NUM>, which affects the degree of torque transmission between the input 32a and output 32b, is controlled by controller <NUM>. That degree of energization may be controlled manually by an operator of the machine <NUM>, or automatically by a program in the memory of controller <NUM>. The degree of energization may be adjusted (metered) by closed loop control of the rotational speed of augers <NUM>, <NUM> and <NUM>, for which the relationship between auger speed and the volume transport rate is known, in order to provide a specific grain unload rate. The speed of the augers may be monitored for the closed loop control using a rotation sensor, or the unload rate may be monitored for the closed loop control using a flow measurement device, for example. The degree of energization may also be adjusted (metered) as a function of a sensed condition, such as a material clog or jam in augers <NUM>, <NUM>, <NUM> that is detected by a pressure sensor <NUM> (<FIG>) associated with output component 32b or one of the augers. Alternatively, the sensor <NUM> may sense a resistance to motion (i.e., rotation) of the output component 32b or auger. If a material clog is detected, then the pressure sensor <NUM> will communicate the same to the controller <NUM>, and the controller <NUM> will disengage the clutch <NUM> to cease operation of the output component 32b.

Controller <NUM> may also communicate with a fill sensor <NUM> located at or near the top of grain receptacle <NUM>. In operation, as the grain fills the receptacle <NUM> and eventually reaches the fill sensor <NUM>, the fill sensor <NUM> transmits a signal to controller <NUM> such that the controller <NUM> understands the fill status of receptacle <NUM>. In response thereto, controller <NUM> slowly energizes coil assembly <NUM> via controller <NUM> to close the opening <NUM> in clutch <NUM>, thereby slowing the introduction of grain into receptacle <NUM>. Eventually, controller <NUM> opens the opening <NUM> to a degree in which the input 32a and output 32b are coupled.

Although clutch <NUM> is described for use with apparatus <NUM> for feeding or conveying the grain contained therein to unloader conveyor <NUM>, it should be understood that clutch <NUM> can be employed in other areas of machine <NUM> requiring variable speed between input and output components by varying torque transmission.

It is to be understood that the above-described operating 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, such as the aforementioned method of operation, is implemented in software code or instructions which are tangibly stored on the tangible computer readable medium. Upon loading and executing such software code or instructions by the controller, the controller may perform any of the functionality of the controller described herein, including any steps of the aforementioned method described herein.

Claim 1:
An agricultural vehicle [<NUM>], in particular a combine harvester [<NUM>], comprising an apparatus [<NUM>] for feeding or conveying grain including a conveyor [<NUM>/<NUM>] for moving grain and having an input end and an output end, wherein the apparatus [<NUM>] further comprises an electromagnetically actuated viscous clutch [<NUM>] either directly or indirectly connected to the input end of the conveyor [<NUM>/<NUM>] for transmitting torque from an input component [32a] to the input end of the conveyor [<NUM>/<NUM>],
characterized in that :
the apparatus [<NUM>] further comprises a controller [<NUM>] that is configured to either energize or deenergize the electromagnetically actuated viscous clutch
clutch [<NUM>] to adjust a torque imparted to the conveyor [<NUM>/<NUM>] by the input component [32a], and
the apparatus [<NUM>] further comprises a sensor [<NUM>] connected to the controller [<NUM>] for detecting motion of the conveyor [<NUM>/<NUM>], and wherein the controller [<NUM>] is configured to adjust a torque transmitted by the viscous clutch [<NUM>] as a function of the detected motion.