Patent Description:
An agricultural harvester known as a "combine" is historically termed such because it combines multiple harvesting functions with a single harvesting unit, such as picking, threshing, separating, and cleaning. A combine includes a header, which removes the crop from a field, and a feeder housing which transports the crop matter to a threshing and cleaning system. The threshing and cleaning system may include a threshing rotor that rotates within a housing and performs a threshing operation on the crop material to remove the grain. The housing may include adjustable concaves with perforations for the grain to pass therethrough. Once the grain is threshed, it falls through the perforations in the concaves onto a grain pan. From the grain pan, the grain is cleaned using the cleaning system, which generally includes one or more sieves and a cleaning fan. The cleaning fan blows air through the sieves to discharge chaff and other debris toward the rear of the combine. The clean grain is then transported to a grain tank onboard the combine via a clean grain auger. Material other than grain (MOG), such as straw, debris, dust, etc., from the threshing section proceeds through a residue system, which may utilize a straw chopper to process the MOG and direct it out through the rear of the combine. Typically, a combine is equipped with side doors that allow an operator to easily access the threshing and cleaning system.

A corn header generally includes a conveyor, row units, and accompanying drive architecture to power the header. The conveyor is disposed aft of the row units and it may be in the form of a conveyor belt, an auger with a tubular shaft having left and right flighting, or a combination of both. The row units generally include snouts, gathering chains, and stalk rolls. The corn header may also include chopping units, also known as "choppers", located underneath the stalk rolls. The snouts are conically shaped to pass in between the rows of corn, defining a designated passageway in between the snouts for the rows of corn to travel therein. Hence, a respective row unit may have a slot to receive a respective row of corn. Each row unit also includes respective gearboxes to drive the gathering chains and stalk rolls. A gathering chain generally includes chain links that form an endless chain and protuberances, such as paddles, affixed thereto for contacting the corn stalks. As the combine traverses the field, the corn stalks are pulled inwardly by the gathering chains and downwardly by the stalk rolls. This motion causes the ears of corn to contact the base of the header, e.g. deck plate, and snap off from their respective stalks. The gathering chains additionally help to move crop material inwardly towards the conveyor, which transports the ears of corn to the center of the header for entry into the feeder housing. The stripped corn stalks are further pinched and crushed by the stalk rolls, in order to accelerate the decomposition process of the stalks. The chopping units include rotating blades, located beneath the stalk rolls, which chop the stalks, leaves, or other MOG into smaller pieces for expediting the decomposition thereof.

Some corn headers may include a split drive system with separate drivelines and gearboxes for individually and respectively driving the row units and chopping units. For instance, each row unit may include a gearbox for driving the gathering chains and stalk rolls. Each row-unit gearbox may be operably connected to and driven by a single row-unit driveline, which in turn is operably driven by the power take off (PTO) of the combine. Hence, independently from the row units, the chopping units may be driven by a separate set of chopper gearboxes coupled to a separate chopper driveline which is driven by the PTO.

During engagement or in-field operation of the header, the chopping units may cause a spike in torque within the chopper driveline which may damage the driveline of the combine. For example, the spikes in torque may bend, break, or otherwise damage the intermediary drive shaft and/or the jack shaft of the feeder housing. As can be appreciated, the idle speed of the engine and/or the control system of the combine may affect the severity of the torque spikes during the startup operation of the header. Hence, such torque spikes may limit header-combine compatibility since some headers may inevitably damage an incompatible combine. <CIT> refers to a header of an agricultural combine or header including all the features in the preamble of claim <NUM>.

What is needed in the art is a drive system for a header that efficiently reduces torque spikes in the header in order to increase the compatibility of the header.

The invention is defined as set out in independent claim <NUM>.

In one exemplary embodiment formed in accordance with the present invention there is provided a drive system of a header that includes a gearbox and a torque damper. The torque damper operably connects the gearbox to the drive shaft which transmits motive power from the combine to the header. The torque damper reduces a magnitude of a torque spike, caused by the driven components of the header, to protect the driveline components of the header and/or combine during an initial startup and/or harvesting operation of the header.

In another exemplary embodiment formed in accordance with the present invention, there is provided a drive system of a header for an agricultural vehicle. The header includes a plurality of driven devices. The drive system includes a shaft configured for conveying motive power from the agricultural vehicle to the header, a gearbox configured for being located on the header and for transferring motive power to the plurality of driven devices, and a torque damper. The torque damper is operably connected in between the shaft and the gearbox. The torque damper is configured for reducing a magnitude of a torque spike.

In yet another exemplary embodiment formed in accordance with the present invention, there is provided an agricultural vehicle that includes a chassis, a prime mover supported by the chassis and configured for providing motive power, a header connected to the chassis and including a plurality of driven devices, and a drive system for driving the plurality of driven devices. The drive system includes a shaft connected in between the header and the chassis and configured for conveying motive power from the prime mover to the header, a gearbox located on the header and configured for transferring motive power to the plurality of driven devices, and a torque damper. The torque damper is operably connected in between the shaft and the gearbox. The torque damper is configured for reducing a magnitude of a torque spike.

In yet another example not according to the invention, there is provided a method for operating a header for an agricultural vehicle. The header includes a plurality of driven devices. The method includes the initial step of providing a drive system for driving the plurality of driven devices. The drive system includes a shaft configured for conveying motive power from the agricultural vehicle to the header, a gearbox configured for being located on the header and for transferring motive power to the plurality of driven devices, and a torque damper. The torque damper is operably connected in between the shaft and the gearbox. The method also includes connecting the header to the agricultural vehicle, initializing a startup operation of the header and starting the header, and dampening a magnitude of a torque spike, by the torque damper, in the startup operation.

One possible advantage of the exemplary embodiment of the drive system is that the torque damper diminishes a magnitude of the spikes in torque caused by the driven elements of the header and transmuted back through the driveline of the header and/or combine.

Another possible advantage of the exemplary embodiment of the drive system is that torque damper allows the header to be compatible with various differing combines.

The terms "forward", "rearward", "left" and "right", when used in connection with the agricultural harvester and/or components thereof are usually determined with reference to the direction of forward operative travel of the harvester, but they should not be construed as limiting. The terms "longitudinal" and "transverse" are determined with reference to the fore- and-aft direction of the agricultural harvester and are equally not to be construed as limiting. The terms "downstream" and "upstream" are determined with reference to the intended direction of crop material flow during operation, with "downstream" being analogous to "rearward" and "upstream" being analogous to "forward. " The term startup operation of the header may refer to a process and time during which motive power is initially provided to one or more driven devices of the header and the driven devices in order to startup the driven devices. The term harvesting operation of the header may refer to a process wherein the header is cutting and/or gathering the crop material from the field.

Referring now to the drawings, and more particularly to <FIG>, there is shown an exemplary embodiment of an agricultural vehicle <NUM>. The agricultural vehicle <NUM> may generally include a chassis <NUM>, wheels <NUM> driven by a prime mover <NUM>, an operator cab <NUM>, a feeder housing <NUM> pivotally connected to the chassis <NUM>, and a header <NUM>. The agricultural vehicle <NUM> may be in the form of any desired agricultural vehicle, such as a combine <NUM>.

The header <NUM> may be connected to the feeder housing <NUM>. The header <NUM> removes and gathers the crop material from the field as the agricultural vehicle <NUM> traverses across the field in a forward direction of travel "F". The header <NUM> may be in the form of any desired header, such as a corn header <NUM>. The corn header <NUM> may include a header frame <NUM>, multiple snouts <NUM> which define channels therebetween for receiving the rows of corn, a crop conveyor <NUM>, such as an auger <NUM>, to convey the crop material inwardly toward the feeder housing <NUM>, and multiple row units <NUM> connected to and supported by the frame <NUM>.

Each row unit <NUM> generally includes gathering chains and stalk rolls (not shown). The row units <NUM> may be driven by gearboxes coupled to one or more cross shaft(s), which are operably coupled to the agricultural vehicle <NUM>. The gathering chains and the stalk rolls may be respectively in the form of any desired gathering chains and stalk rolls.

Referring now collectively to <FIG>, there is shown an exemplary embodiment of a drive system <NUM> of the header <NUM> for driving multiple driven devices, e.g. row units and/or choppers <NUM>. The drive system <NUM> is a split drive system with a row-unit drive portion and a chopper-unit drive portion which transmits motive power to the choppers <NUM>. In the chopper-unit drive portion, the drive system <NUM> generally includes a drive shaft <NUM>, a gearbox <NUM>, and a torque damper <NUM> operably connected in between the shaft <NUM> and the gearbox <NUM> for reducing a magnitude of a torque spike during a startup operation of the header <NUM> and/or a harvesting operation of the header <NUM>. The drive system <NUM> also includes a coupling assembly <NUM> which operably connects the torque damper <NUM> to the shaft <NUM> and the gearbox <NUM>. As shown, the drive system <NUM> is integrated into a corn header for driving choppers <NUM>; however, it should be appreciated that the drive system <NUM> may be integrated into any desired header, for example a draper head or pickup head. Furthermore, it should be appreciated that the components of the drive system <NUM> may be incorporated as part of the header <NUM> and/or the agricultural vehicle <NUM>.

The choppers <NUM>, which are schematically illustrated in <FIG>, may include reciprocating knives that are located underneath the stalk rolls for chopping the remaining crop material into smaller pieces. The choppers <NUM> may be separately driven from the gathering chains and stalk rolls. Hence, the choppers <NUM> may be driven by designated gearboxes and cross shaft(s) which are operably coupled to and independently driven by the agricultural vehicle <NUM>. The choppers <NUM> may be in the form of any desired choppers.

The shaft <NUM> may be a power take off (PTO) shaft <NUM> of the agricultural vehicle <NUM> which extends outwardly from the feeder housing <NUM>. More particularly, the shaft <NUM> may be operably connected in between the feeder drive jack shaft of the feeder housing <NUM> and the torque damper <NUM> via the coupling assembly <NUM>. In operation, the drive system <NUM> may experience torque spikes which may damage the shaft <NUM> and/or the feeder drive jack shaft. For example, the feeder drive jack shaft may become bent and/or broken if a torque spike from the header <NUM> exceeds its operational stress limits. The drive shaft <NUM> can be in the form of any desired shaft for transmitting motive power from the agricultural vehicle <NUM> to the driven devices, e.g. choppers <NUM>, of the header <NUM>.

The gearbox <NUM> is connected to and supported by the header <NUM>. The gearbox <NUM> transfers motive power from the shaft <NUM> to the driven devices, e.g. choppers <NUM>, of the header <NUM>. The gearbox <NUM> may be in the form of a back-sheet gearbox <NUM> which is affixed to the backside of the frame <NUM> of the header <NUM>. The gearbox <NUM> includes a gearbox shaft <NUM>, e.g. splined input shaft <NUM>, with a receiving hole <NUM> therein (<FIG>). The gearbox <NUM> may be in the form of any desired gearbox.

The torque damper <NUM> is operably connected in between the shaft <NUM> and the gearbox <NUM>. The torque damper <NUM> may include multiple torsional springs <NUM> disposed within a housing <NUM>. The torque damper <NUM> may reduce torsional spikes at start up, shut down, idle, and/or during a harvesting operation. The torque damper <NUM> may be in the form of any desired torque damper. For example, the torque damper may comprise a spring type torque damper <NUM>, a fluid coupling type damper, and/or a flexible coupling type damper.

The coupling assembly <NUM> includes an adapter <NUM> operably connecting the torque damper <NUM> to the yoke of the shaft <NUM>, a sleeve <NUM> connected to the shaft <NUM> of the gearbox <NUM>, and a bearing <NUM> mounted on the sleeve <NUM>. The adapter <NUM> may be in the form of a uniform plate with a left end connected to the yoke of the shaft <NUM>, via fasteners, and a right end connected to the torque damper <NUM>, via fasteners. It is conceivable that coupling assembly <NUM> may not include an adaptor <NUM> such that the drive shaft <NUM> directly connects to the torque damper <NUM>.

The sleeve <NUM> is rigidly mounted onto the gearbox shaft <NUM> by splines and/or one or more fasteners. For example, the sleeve <NUM> can be connected to the gearbox shaft <NUM> by splines (unnumbered), a fastener <NUM>, and an end washer <NUM> (<FIG>). The fastener <NUM> is disposed within and threadedly engaged with the hole <NUM>. The washer <NUM> is engaged with the fastener <NUM> and a corresponding inner lip of the sleeve <NUM> such that the fastener <NUM> and the washer <NUM> rigidly connect the sleeve <NUM> to the gearbox shaft <NUM>. The sleeve <NUM> comprises a first, left end mounting the bearing <NUM> and a second, right end mounting the torque damper <NUM> such that the adapter <NUM> and the torque damper <NUM> are both supported by the sleeve <NUM>. The sleeve <NUM> comprises an outer splined surface (unnumbered) engaging with the bearing <NUM> and the torque damper <NUM>, a first bore 224A with a first diameter, and a second bore 224B with a second diameter which is different than the first diameter. The first bore 224A houses and engages with the washer <NUM>, and the second bore 224B receives and engages with the gearbox shaft <NUM>.

Referring now collectively to <FIG> and <FIG>, there is shown another exemplary embodiment of a drive system <NUM> of the header <NUM> for driving multiple driven devices, e.g. row units and/or choppers <NUM>. The drive system <NUM> may be substantially similar to the drive system <NUM>, except that the drive system <NUM> additionally includes an overrunning clutch <NUM> with a splined input coupler <NUM> and an output yoke <NUM>. The drive system <NUM> may generally include a drive shaft <NUM>, a gearbox <NUM>, a torque damper <NUM> operably connected in between the shaft <NUM> and the gearbox <NUM>, and a coupling assembly <NUM> with an adapter <NUM> that operably connects the torque damper <NUM> to the yoke <NUM> of the overrunning clutch <NUM>. It should be appreciated that the drive system <NUM> may be integrated into any desired header, for example a corn head, draper head, or pickup head.

The overrunning clutch <NUM> is connected in between the shaft <NUM> and the adapter <NUM>. The overrunning clutch <NUM> is configured for protecting the shaft <NUM> by disconnecting the shaft <NUM> from the adapter <NUM> when the input shaft (not shown) of the gearbox <NUM> rotates faster than the shaft <NUM>. The overrunning clutch <NUM> may be in the form of any desired overrunning clutch.

The torque damper <NUM> is coupled in between the gearbox <NUM> and the adapter <NUM>. The torque damper <NUM> may include a splined coupler <NUM>, multiple torsional springs <NUM>, and a two-part plate housing <NUM> for at least partially housing the torsional springs <NUM> (<FIG>). The torque damper <NUM> may directly connect to the input shaft of the gearbox <NUM> via the coupler <NUM>. The torque damper <NUM> may be connected to the adapter <NUM> by one or fasteners. As can be appreciated, the torque damper <NUM> may also include a housing which entirely covers the torsional springs <NUM>. Alternatively, the torque damper <NUM> and the coupling assembly <NUM> may be disposed within a common housing. Also, it should be appreciated that the coupling assembly <NUM> may or may not include a designated splined sleeve <NUM>, fastener <NUM>, and washer <NUM>, as discussed above. The torque damper <NUM> may be in the form of any desired torque damper. For example, the torque damper may comprise a spring type torque damper <NUM>, a fluid coupling type damper, and/or a flexible coupling type damper.

In operation, the torque damper <NUM>, <NUM> may automatically dampen torque spikes during a startup and/or harvesting operation of the header <NUM>. For instance, the operator may connect the header <NUM> to the agricultural vehicle <NUM> and initialize the startup operation wherein motive power is initially provided to the choppers <NUM> of the header <NUM>. During this initial power startup, the choppers <NUM> may cause a spike in torque, which is subsequently experienced by the shaft <NUM>, <NUM> and/or feeder drive jack shaft of the feeder housing <NUM>. For instance, the engagement peak torque without a torque damper <NUM>, <NUM>, as measured between the left and right ends of the shaft <NUM>, <NUM> may be approximately <NUM>-<NUM> in-lbs (<NUM> - <NUM>).

Such high torque spikes may cause bend, break, or otherwise damage to the shaft <NUM>, <NUM> and/or the feeder drive jack shaft, which may have an operating torque limit of approximately <NUM> in-lbs (<NUM>). Therefore, the torque damper <NUM>, <NUM> may be vital to dampen the torque spike(s) during startup of the header <NUM> in order to protect the shaft <NUM>, <NUM> and/or feeder drive jack shaft. As can be appreciated, during the startup operation, the engine <NUM> of the agricultural vehicle <NUM> may idle at <NUM>-<NUM> rpm. Also, for example, the torque damper <NUM>, <NUM> may dampen any torque spikes during the harvesting operation. For instance, a foreign object may contact the choppers <NUM>, causing a spike in torque, and the torque damper <NUM>, <NUM> may also automatically dampen the magnitude of the torque spike in the harvesting operation.

Claim 1:
A drive system (<NUM>, <NUM>) of a header (<NUM>) for an agricultural vehicle (<NUM>), the header (<NUM>) comprising a plurality of driven devices (<NUM>), the drive system (<NUM>, <NUM>) comprising:
a shaft (<NUM>, <NUM>) configured for conveying motive power from the agricultural vehicle (<NUM>) to the header (<NUM>);
a gearbox (<NUM>, <NUM>) configured for being located on the header (<NUM>) and for transferring motive power to the plurality of driven devices (<NUM>); and
a torque damper (<NUM>, <NUM>) operably connected in between the shaft (<NUM>, <NUM>) and the gearbox (<NUM>, <NUM>), and the torque damper (<NUM>, <NUM>) being configured for reducing a magnitude of a torque spike;
characterized in that
the drive system (<NUM>, <NUM>) further comprises a coupling assembly (<NUM>, <NUM>) which operably connects the torque damper (<NUM>, <NUM>) to the shaft (<NUM>, <NUM>) and the gearbox (<NUM>, <NUM>), wherein the gearbox (<NUM>) comprises a gearbox shaft (<NUM>), and wherein the coupling assembly (<NUM>) comprises a sleeve (<NUM>) that is rigidly mounted onto the gearbox shaft (<NUM>).